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  • 1. Abarca, R. R. M.
    et al.
    Gaudio, M. T.
    Chakraborty, S.
    Bhattacharya, Prosun
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Hållbar utveckling, miljövetenskap och teknik, Vatten- och miljöteknik.
    Metals toxic pollutants in the environment: Anthropogenic and geological causes and remediation2019Ingår i: Current Trends and Future Developments on (Bio-) Membranes: Membranes in Environmental Applications, Elsevier Inc. , 2019, s. 109-124Kapitel i bok, del av antologi (Övrigt vetenskapligt)
    Abstract [en]

    Heavy metals are naturally present in nature, but if their concentration is higher than the normal accepted threshold levels, they constitute one of the pollutants that is more difficult to remove and also to rehabilitate the contaminated site by them. There are many heavy-metal pollutants-the most common among them are arsenic (As), chromium (Cr), lead (Pb), mercury (Hg), cadmium (Cd), cobalt (Co), copper (Cu), iron (Fe), magnesium (Mg), manganese (Mn), molybdenum (Mo), nickel (Ni), selenium (Se), and zinc (Zn), along with the less common ones, which produced, for example, by the nuclear process, such as uranium (U)-in different configuration; hence, many possibilities of contamination in the world exist, and they are more difficult to remove.Thus heavy-metal pollution is more and more becoming one of the principal issues of the global interest, because it is common to both industrialized countries and developing countries. These issues are getting hard to be recognized and cannot be followed the simple rules concerning safety and environmental protection, thus fall into the same errors of the already industrialized countries. At the same time, new environment-remediation techniques are developed in the last decade, especially, in these last years. Some of these technologies concern physical or chemical process or effects, such as ion exchanges, flotations, and photocatalysis, while other technologies concern the use of membrane process, especially ultrafiltration or membrane integrated process or hybrid systems, where membranes are generally submerged and used together with another process.In this chapter a review of this problem and some example of technologies for removing and remediation of the environment are reported. 

  • 2. Abbak, Ramazan A.
    et al.
    Sjöberg, Lars E.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Samhällsplanering och miljö, Geodesi och geoinformatik.
    Ellmann, Artu
    Ustun, Aydin
    A precise gravimetric geoid model in a mountainous area with scarce gravity data: a case study in central Turkey2012Ingår i: Studia Geophysica et Geodaetica, ISSN 0039-3169, E-ISSN 1573-1626, Vol. 56, nr 4, s. 909-927Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In mountainous regions with scarce gravity data, gravimetric geoid determination is a difficult task that needs special attention to obtain reliable results satisfying the demands, e.g., of engineering applications. The present study investigates a procedure for combining a suitable global geopotential model and available terrestrial data in order to obtain a precise regional geoid model for Konya Closed Basin (KCB). The KCB is located in the central part of Turkey, where a very limited amount of terrestrial gravity data is available. Various data sources, such as the Turkish digital elevation model with 3 '' x 3 '' resolution, a recently published satellite-only global geopotential model from the Gravity Recovery and Climate Experiment satellite (GRACE) and the ground gravity observations, are combined in the least-squares sense by the modified Stokes' formula. The new gravimetric geoid model is compared with Global Positioning System (GPS)/levelling at the control points, resulting in the Root Mean Square Error (RMS) differences of +/- 6.4 cm and 1.7 ppm in the absolute and relative senses, respectively. This regional geoid model appears to he more accurate than the Earth Gravitational Model 2008, which is the best global model over the target area, with the RMS differences of +/- 8.6 cm and 1.8 ppm in the absolute and relative senses, respectively. These results show that the accuracy of a regional gravimetric model can be augmented by the combination of a global geopotential model and local terrestrial data in mountainous areas even though the quality and resolution of the primary terrestrial data are not satisfactory to the geoid modelling procedure.

  • 3.
    Abbaszadeh Shahri, Abbas
    et al.
    Department of Civil Engineering, Islamic Azad University, Roudehen Branch, Tehran, Iran Johan Lundberg AB, Uppsala, Sweden.
    Larsson, Stefan
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Renkel, Crister
    Johan Lundberg AB, Uppsala, Sweden.
    Correction to: Artificial intelligence models to generate visualized bedrock level: a case study in Sweden (Modeling Earth Systems and Environment, (2020), 6, 3, (1509-1528), 10.1007/s40808-020-00767-0)2020Ingår i: Modeling Earth Systems and Environment, ISSN 2363-6203, E-ISSN 2363-6211, Vol. 6, nr 4Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In the original version of this article, unfortunately a character of the Journal no in the reference 10 has been published incorrectly.

  • 4.
    Abbaszadeh Shahri, Abbas
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Spross, Johan
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Johansson, Fredrik
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Larsson, Stefan
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Landslide susceptibility hazard map in southwest Sweden using artificial neural network2019Ingår i: Catena (Cremlingen. Print), ISSN 0341-8162, E-ISSN 1872-6887, Vol. 183, artikel-id UNSP 104225Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Landslides as major geo-hazards in Sweden adversely impact on nearby environments and socio-economics. In this paper, a landslide susceptibility map using a proposed subdivision approach for a large area in southwest Sweden has been produced. The map has been generated by means of an artificial neural network (ANN) model developed using fourteen causative factors extracted from topographic and geomorphologic, geological, land use, hydrology and hydrogeology characteristics. The landslide inventory map includes 242 events identified from different validated resources and interpreted aerial photographs. The weights of the causative factors employed were analyzed and verified using accepted mathematical criteria, sensitivity analysis, previous studies, and actual landslides. The high accuracy achieved using the ANN model demonstrates a consistent criterion for future landslide susceptibility zonation. Comparisons with earlier susceptibility assessments in the area show the model to be a cost-effective and potentially vital tool for urban planners in developing cities and municipalities.

  • 5.
    Abdi, Amir
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Tillämpad termodynamik och kylteknik.
    Sawalha, Samer
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Tillämpad termodynamik och kylteknik.
    Karampour, Mazyar
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Tillämpad termodynamik och kylteknik.
    Heat recovery investigation of a supermarket refrigeration system using carbon dioxide as refrigerant2014Ingår i: 11th IIR Gustav Lorentzen Conference on Natural Refrigerants: Natural Refrigerants and Environmental Protection, GL 2014, International Institute of Refrigeration, 2014, s. 277-285Konferensbidrag (Refereegranskat)
    Abstract [en]

    This study investigates the heat reclaim of trans-critical CO2-booster refrigeration unit in a supermarket in Sweden. The aim is to compare the control strategy for heat recovery in real supermarket installation to the optimum control strategy.

    The optimum control strategy based on theoretical analysis is explained. By analyzing field measurement of a supermarket, heat recovery in the refrigeration system is studied and compared to the optimum case. To investigate the potential of higher heat recovery rate, a computer model is developed based on the optimum control strategy.  The model is also used to calculate the boundary conditions at which the system should run for highest COP.

    The results show that heat can be recovered at heating COP of 3-4.5. The theoretical analysis shows that the amount of heat that can be recovered from the refrigeration system is about 1.3 times (130 %) the cooling demand in the system. However the analysis of the field measurements shows that only between 30-60 % of the available heat to be recovered is utilized, the rest is released to outdoors. The analysis in this study shows that there is a potential to recover much more heat from the refrigeration system at relatively high heating COP compared to heat pump.

  • 6.
    Abdollahzadeh, Makan
    et al.
    K.N.Toosi University of Technology, Faculty of Geodesy and Geomatic Engineering, Tehran, Iran.
    Eshagh, Mehdi
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Transporter och samhällsekonomi, Geodesi.
    Najafi, Mehdi
    K.N.Toosi University of Technology, Faculty of Geodesy and Geomatic Engineering, Tehran, Iran.
    A semi-vectorization algorithm to synthesis of gravitational anomaly quantities on the Earth's surface2009Konferensbidrag (Refereegranskat)
    Abstract [en]

    The Earth’s gravitational potential can be expressed by the well-known spherical harmonic expansion. The computationaltime of summing up this expansion is an important practical issue which can be reduced by an efficientnumerical algorithm. This paper proposes such a method for block-wise synthesizing the anomaly quantities onthe Earth surface using vectorization.Fully-vectorization means transformation of the summations to the simple matrix and vector products. It is not apractical for the matrices with large dimensions. Here a semi-vectorization algorithm is proposed to avoid workingwith large vectors and matrices. It speeds up the computations by using one loop for the summation either ondegrees or on orders. The former is a good option to synthesize the anomaly quantities on the Earth surfaceconsidering a digital elevation model (DEM). This approach is more efficient than the two-step method whichcomputes the quantities on the reference ellipsoid and continues them upward to the Earth surface. The algorithmhas been coded in MATLAB which synthesizes a global grid of 50 x 50 (corresponding 9 million points) of gravityanomaly or geoid height using a geopotential model to degree 360 in 10000 seconds by an ordinary computer with2G RAM.

  • 7.
    Abdollahzadeh, Makan
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Samhällsplanering och miljö, Geodesi och geoinformatik.
    Najafi-Alamdari, Mehdi
    Geodesy, KNToosi Uni. Tech..
    Application of Molodensky's Method for Precise Determination of Geoid in Iran2011Ingår i: Journal of Geodetic Science, ISSN 2081-9919, E-ISSN 2081-9943, Vol. 1, nr 3, s. 259-270Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Determination of the geoid with a high accuracy is a challenging task among geodesists. Its precise determination is usually carried out by combining a global geopotential model with terrestrial gravity anomalies measured in the region of interest along with some topographic information. In this paper, Molodensky's approach is used for precise determination of height anomaly. To do this, optimum combination of global geopotential models with the validated terrestrial surface gravity anomalies and some deterministic modification schemes are investigated. Special attention is paid on the strict modelling of the geoidal height and height anomaly difference. The accuracy of the determined geoid is tested on the 513 points of Iranian height network the geoidal height of which are determined by the GPS observations.

  • 8.
    Abdullah Asif, Farazee Mohammad
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Industriell produktion.
    Lieder, Michael
    KTH, Skolan för industriell teknik och management (ITM), Industriell produktion.
    Rashid, Amir
    KTH, Skolan för industriell teknik och management (ITM), Industriell produktion.
    Multi-method simulation based tool to evaluate economic and environmental performance of circular product systems2016Ingår i: Journal of Cleaner Production, ISSN 0959-6526, E-ISSN 1879-1786, Vol. 139, s. 1261-1281Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Purpose: The transition from linear to circular product systems is a big step for any organization. This may require an organization to change the way it does business, designs product and manages supply chain. As these three areas are interdependent, bringing change in one area will influence the others, for instance, changing the business model from conventional sales to leasing will demand changes in both product design and the supply chain. At the same time, it is essential for an organization to anticipate the economic and environmental impact of all changes before it may decide to implement the circular product systems. However, there is no tool available today that can assess economic and environmental performance of circular product systems. The purpose of this research is to develop a multi-method simulation based tool that can help to evaluate economic and environmental performance of circular product systems. Method: The conceptual models that are used to develop the tool have been formulated based on review of the state-of-the-art research. System Dynamics (SD) and Agent Based (AB) principles have been used to create the simulation model which has been implemented in Anylogic software platform. Originality: This research presents the first multi-method simulation based tool that can evaluate economic and environmental performance of circular product systems. Findings: Multi-method simulation technique is useful in designing dynamic simulation model that takes into consideration mutual interactions among critical factors of business model, product design and supply chain. It also allows predicting system's behaviour and its influence on the economic and environmental performance of circular product systems.

  • 9.
    Abdullah Asif, Farazee Mohammad
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Industriell produktion.
    Rashid, Amir
    KTH, Skolan för industriell teknik och management (ITM), Industriell produktion, Maskin- och processteknologi.
    Bianchi, C.
    Nicolescu, Cornel Mihai
    KTH, Skolan för industriell teknik och management (ITM), Industriell produktion.
    System dynamics models for decision making in product multiple lifecycles2015Ingår i: Resources, Conservation and Recycling, ISSN 0921-3449, E-ISSN 1879-0658, Vol. 101, s. 20-33Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The main drivers for adopting product multiple lifecycles are to gain ecological and economic advantages. However, in most of the cases it is not straight forward to estimate the potential ecological and economic gain that may result from adopting product multiple lifecycles. Even though many researchers have concluded that product multiple lifecycles result in gain, there are examples which indicate that the gain is often marginal or even none in many cases. The purpose of this research is to develop system dynamics models that can assist decision makers in assessing and analysing the potential gain of product multiple lifecycles considering the dynamics of material scarcity. The foundation of the research presented in this paper is laid based on literature review. System dynamics principles have been used for modelling and simulations have been done on Stella iThink platform. The data used in the models have been extracted from different reports published by World Steel Association and U.S. Geological Survey. Some of the data have been assumed based on expert estimation. The data on iron ore reserves, iron and steel productions and consumptions have been used in the models. This research presents the first system dynamics model for decision making in product multiple lifecycles which takes into consideration the dynamics of material scarcity. Physical unavailability and price of material are the two main factors that would drive product multiple lifecycles approach and more sustainable decisions can be made if it is done by taking holistic system approach over longer time horizon. For an enterprise it is perhaps not attractive to conserve a particular type of material through product multiple lifecycles approach which is naturally abundant but extremely important if the material becomes critical. An enterprise could through engineering, proper business model and marketing may increase the share of multiple lifecycle products which eventually would help the enterprise to reduce its dependency on critical materials.

  • 10.
    Abhishek, Sarabjot
    et al.
    Dr BR Ambedkar Natl Inst Technol, Dept Phys, GT Rd Bye Pass, Jalandhar 144027, Punjab, India..
    Kaur, Sarabjot
    KTH, Skolan för teknikvetenskap (SCI), Fysik, Kärnfysik.
    Mehra, Rohit
    Dr BR Ambedkar Natl Inst Technol, Dept Phys, GT Rd Bye Pass, Jalandhar 144027, Punjab, India..
    Estimation of Uranium and Related Health Risks Due to Consumption of Groundwater in Lower Himalayas2023Ingår i: Indian Journal of Pure & Applied Physics, ISSN 0019-5596, E-ISSN 0975-1041, Vol. 61, nr 6, s. 478-483Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Exposure to uranium via ingestion of edible products may lead to serious health hazards when taken in quantities more than recommended limit. Hence, to assess the uranium content in groundwater and concerned health hazards 64 groundwater samples were collected from Hamirpur and Mandi districts of Himachal Pradesh. The samples were collected in pre monsoon season from the handpumps and bowries. The region lies in Lower Himalayan range which is storehouse of various granatic rocks. Presence of uranium deposits in Tileli (Mandi), Rajpura (Una), Lambehra (Hamirpur) makes the area more vulnerable for the study. The groundwater samples were analysed to measure concentration of uranium using LED Fluorimeter developed by Quantalase Private. Limited. The uranium concentration in groundwater samples varied from 0.25 to 17.29 & mu;g L-1, with an average value of 1.97. Uranium concentration in none of the samples surpassed the limit of 30 & mu;g L-1 recommended by WHO(2011), 60 & mu;g L-1 set by AERB(2004). Health risks were estimated in terms radiological and chemical toxicity for different isotopes of uranium. The calculated average mortality and morbidity risks were lower than the actual prescribed limit. The average Lifetime Average Daily Dose (LADD) was calculated as 0.04 and Hazard Quotient (HQ) below unity. Annual ingestion doses for different age groups were also measured which lies under safe limit. Thus, it is recommended that the groundwater is safe for consumption by public. Using Hair Compartment Model for uranium and mean daily uranium intake of 2.71 & mu;g for 60-year exposure period, organ specific doses due to uranium radioisotopes in prime organs/tissues and excretion rates via urine, faeces and hair pathway are estimated.

  • 11. Abiye, T. A.
    et al.
    Bhattacharya, Prosun
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Hållbar utveckling, miljövetenskap och teknik.
    Arsenic concentration in groundwater: Archetypal study from South Africa2019Ingår i: Groundwater for Sustainable Development, ISSN 2352-801X, Vol. 9, artikel-id 100246Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    South Africa does not have significant surface water resources, which is often easily affected by unpredictable and rapidly changing climatic variables, due to its location in the arid and semi-arid climatic setting. In large part of the country, groundwater from weathered and fractured crystalline rocks plays pivotal role in sustaining the livelihood, often it contains toxic metals released from the host rocks. The host rocks that are responsible for arsenic release in groundwater are primarily enriched due to metamorphism and igneous processes that resulted in the enrichment of economic minerals. Preliminary assessment indicates that the main arsenic containing minerals are arsenopyrite (FeAsS), arsenical oxide, sulpharsenide, arsenopyritical reefs, leucopyrite, löllingite (FeAs2) and scorodite (FeAsO4·2H2O). Owing to the release of arsenic from highly mineralized rocks that constitute the aquifers, arsenic concentration in the groundwater reaches up to 253 μg/L (Namaqualand), 6150 μg/L (west of Johannesburg), about 500 μg/L in the Karoo aquifers, considerably higher than the WHO guideline value of 10 μg/L. Acid mine drainage from coal and gold mining is also found to be an important source of arsenic and other toxic metals in groundwater.

  • 12. Abrehdary, M.
    et al.
    Sjoberg, Lars E.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Fastigheter och byggande, Geodesi och satellitpositionering.
    Sampietro, D.
    Contribution of satellite altimetry in modelling Moho density contrast in oceanic areas2019Ingår i: Journal of Applied Geodesy, ISSN 1862-9016, E-ISSN 1862-9024, Vol. 13, nr 1, s. 33-40Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The determination of the oceanic Moho (or crust-mantle) density contrast derived from seismic acquisitions suffers from severe lack of data in large parts of the oceans, where have not yet been sufficiently covered by such data. In order to overcome this limitation, gravitational field models obtained by means of satellite altimetry missions can be proficiently exploited, as they provide global uniform information with a sufficient accuracy and resolution for such a task. In this article, we estimate a new Moho density contrast model named MDC2018, using the marine gravity field from satellite altimetry in combination with a seismic-based crustal model and Earth's topographic/bathymetric data. The solution is based on the theory leading to Vening Meinesz-Moritz's isostatic model. The study results in a high-accuracy Moho density contrast model with a resolution of 1° × 1° in oceanic areas. The numerical investigations show that the estimated density contrast ranges from 14.2 to 599.7 kg/m 3 with a global average of 293 kg/m 3 . In order to evaluate the accuracy of the MDC2018 model, the result was compared with some published global models, revealing that our altimetric model is able to image rather reliable information in most of the oceanic areas. However, the differences between this model and the published results are most notable along the coastal and polar zones, which are most likely due to that the quality and coverage of the satellite altimetry data are worsened in these regions.

  • 13. Abrehdary, M.
    et al.
    Sjöberg, Lars
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Fastigheter och byggande, Geodesi och satellitpositionering.
    A New Moho Depth Model for Fennoscandia with Special Correction for the Glacial Isostatic Effect2021Ingår i: Pure and Applied Geophysics, ISSN 0033-4553, E-ISSN 1420-9136, Vol. 178, nr 3, s. 877-888Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this study, we present a new Moho depth model in Fennoscandia and its surroundings. The model is tailored from data sets of XGM2019e gravitationl field, Earth2014 topography and seismic crustal model CRUST1.0 using the Vening Meinesz-Moritz model based on isostatic theory to a resolution of 1° × 1°. To that end, the refined Bouguer gravity disturbance is determined by reducing the observed field for gravity effect of topography, density heterogeneities related to bathymetry, ice, sediments, and other crustal components. Moreover, stripping of non-isostatic effects of gravity signals from mass anomalies below the crust due to crustal thickening/thinning, thermal expansion of the mantle, Delayed Glacial Isostatic Adjustment (DGIA), i.e., the effect of future GIA, and plate flexure has also been performed. As Fennoscandia is a key area for GIA research, we particularly investigate the DGIA effect on the gravity disturbance and gravimetric Moho depth determination in this area. One may ask whether the DGIA effect is sufficiently well removed in the application of the general non-isostatic effects in such an area, and to answer this question, the Moho depth is determined both with and without specific removal of the DGIA effect prior to non-isostatic effect and Moho depth determinations. The numerical results yield that the RMS difference of the Moho depth from our model HVMD19 vs. the seismic CRUST19 and GRAD09 models are 3.8/4.2 km and 3.7/4.0 km when the above strategy for removing the DGIA effect is/is not applied, respectively, and the mean value differences are 1.2/1.4 km and 0.98/1.4 km, respectively. Hence, our study shows that the specific correction for the DGIA effect on gravity disturbance is slightly significant, resulting in individual changes in the gravimetric Moho depth up to − 1.3 km towards the seismic results. On the other hand, our study shows large discrepancies between gravimetric and seismic Moho models along the Norwegian coastline, which might be due to uncompensated non-isostatic effects caused by tectonic motions.

  • 14.
    Abrehdary, M.
    et al.
    Univ West HV, Div Math Comp & Surveying Engn, SE-46186 Trollhättan, Sweden..
    Sjöberg, Lars
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Fastigheter och byggande, Geodesi och satellitpositionering. Univ West HV, Div Math Comp & Surveying Engn, SE-46186 Trollhättan, Sweden.;Royal Inst Technol KTH, Div Geodesy & Satellite Positioning, SE-10044 Stockholm, Sweden..
    Moho density contrast in Antarctica determined by satellite gravity and seismic models2021Ingår i: Geophysical Journal International, ISSN 0956-540X, E-ISSN 1365-246X, Vol. 225, nr 3, s. 1952-1962Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    As recovering the crust-mantle/Moho density contrast (MDC) significantly depends on the properties of the Earth's crust and upper mantle, varying from place to place, it is an oversimplification to define a constant standard value for it. It is especially challenging in Antarctica, where almost all the bedrock is covered with a thick layer of ice, and seismic data cannot provide a sufficient spatial resolution for geological and geophysical applications. As an alternative, we determine the MDC in Antarctica and its surrounding seas with a resolution of 1 degrees x 1 degrees by the Vening Meinesz-Moritz gravimetric-isostatic technique using the XGM2019e Earth Gravitational Model and Earth2014 topographic/bathymetric information along with CRUST1.0 and CRUST19 seismic crustal models. The numerical results show that our model, named HVMDC20, varies from 81 kg m(-3) in the Pacific Antarctic mid-oceanic ridge to 579 kg m(-3) in the Gamburtsev Mountain Range in the central continent with a general average of 403 kg m(-3). To assess our computations, we compare our estimates with those of some other gravimetric as well as seismic models (KTH11, GEMMA12C, KTH15C and CRUST1.0), illustrating that our estimates agree fairly well with KTH15C and CRUST1.0 but rather poor with the other models. In addition, we compare the geological signatures with HVMDC20, showing how the main geological structures contribute to the MDC. Finally, we study the remaining glacial isostatic adjustment effect on gravity to figure out how much it affects the MDC recovery, yielding a correlation of the optimum spectral window (7 <= n <= 12) between XGM2019e and W12a GIA models of the order of similar to 0.6 contributing within a negligible +/- 14 kg m(-3) to the MDC.

  • 15.
    Abrehdary, M.
    et al.
    Univ West HV, Div Math Comp & Surveying Engn, SE-46186 Trollhättan, Sweden..
    Sjöberg, Lars
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Fastigheter och byggande, Geodesi och satellitpositionering. Univ West HV, Div Math Comp & Surveying Engn, SE-46186 Trollhättan, Sweden..
    Recovering Moho constituents from satellite altimetry and gravimetric data for Europe and surroundings2019Ingår i: Journal of Applied Geodesy, ISSN 1862-9016, E-ISSN 1862-9024, Vol. 13, nr 4, s. 291-303Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this research, we present a local Moho model, named MOHV19, including Moho depth and Moho density contrast (or shortly Moho constituents) with corresponding uncertainties, which are mapped from altimetric and gravimetric data (DSNSC08) in addition to seismic tomographic (CRUST1.0) and Earth topographic data (Earth2014) to a resolution of 1 degrees x 1 degrees based on a solution of Vening Meinesz-Moritz' theory of isostasy. The MOHV19 model covers the area of entire European plate along with the surrounding oceans, bounded by latitudes (30 degrees N-82 degrees N) and longitudes (40 degrees W-70 degrees E). The article aims to interpret the Moho model resulted via altimetric and gravimetric information from the geological and geophysical perspectives along with investigating the relation between the Moho depth and Moho density contrast. Our numerical results show that estimated Moho depths range from 7.5 to 57.9 km with continental and oceanic averages of 41.3 +/- 4.9 km and 21.6 +/- 9.2 km, respectively, and an overall average of 30.9 +/- 12.3 km. The estimated Moho density contrast ranges from 60.2 to 565.8 kg/m(3), with averages of 421.8 +/- 57.9 and 284.4 +/- 62.9 kg/m(3) for continental and oceanic regions, respectively, with a total average of 350.3 +/- 91.5 kg/m(3). In most areas, estimated uncertainties in the Moho constituents are less than 3 km and 40 kg/m(3), respectively, but they reach to much more significant values under Iceland, parts of Gulf of Bothnia and along the Kvitoya Island. Comparing the Moho depths estimated by MOHV19 and those derived by CRUST1.0, MDN07, GRAD09 and MD19 models shows that MOHV19 agree fairly well with CRUST1.0 but rather poor with other models. The RMS difference between the Moho density contrasts estimated by MOHV19 and CRUST1.0 models is 49.45 kg/m(3).

  • 16.
    Abrehdary, M.
    et al.
    Uppsala Univ UU, Dept Earth Sci, Div Geophys, SE-75236 Uppsala, Sweden..
    Sjöberg, Lars
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Fastigheter och byggande, Geodesi och satellitpositionering. Uppsala Univ UU, Dept Earth Sci, Div Geophys, SE-75236 Uppsala, Sweden..
    Remaining non-isostatic effects in isostatic-gravimetric Moho determination-is it needed?2023Ingår i: Geophysical Journal International, ISSN 0956-540X, E-ISSN 1365-246X, Vol. 234, nr 3, s. 2066-2074Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    For long time the study of the Moho discontinuity (or Moho) has been a crucial topic in inferring the dynamics of the Earth's interior, and with profitable result it is mapped by seismic data, but due to the heterogeneous distribution of such data the quality varies over the world. Nevertheless, with the advent of satellite gravity missions, it is today possible to recover the Moho constituents (i.e. Moho depth; MD and Moho density contrast; MDC) via gravity observations based on isostatic models. Prior to using gravity observations for this application it must be stripped due to the gravitational contributions of known anomalous crustal density structures, mainly density variations of oceans, glacial ice sheets and sediment basins (i.e. stripping gravity corrections). In addition, the gravity signals related mainly with masses below the crust must also be removed. The main purpose of this study is to estimate the significance of removing also remaining non-isostatic effects (RNIEs) on gravity, that is, gravity effects that remain after the stripping corrections. This is carried out by using CRUST19 seismic crustal model and employing Vening Meinesz-Moritz (VMM) gravimetric-isostatic model in recovering the Moho constituents on a global scale to a resolution of 1 degrees x 1 degrees. To reach this goal, we present a new model, named MHUU22, formed by the SGGUGM2 gravitational field, Earth2014 topography, CRUST1.0 and CRUST19 seismic crustal models. Particularly, this study has its main emphasis on the RNIEs on gravity and Moho constituents to find out if we can modify the stripping gravity corrections by a specific correction of the RNIEs. The numerical results illustrate that the RMS differences between MHUU22 MD and the seismic model CRUST1.0 and least-squares combined model MOHV21 are reduced by 33 and 41 per cent by applying the NIEs, and the RMS differences between MHUU22 MDC and the seismic model CRUST1.0 and least-squares combined model MDC21 are reduced by 41 and 23 per cent when the above strategy for removing the RNIEs is applied. Hence, our study demonstrates that the specific correction for the RNIEs on gravity disturbance is significant, resulting in remarkable improvements in MHUU22, which more clearly visualize several crustal structures.

  • 17.
    Abrehdary, M.
    et al.
    Division of Mathematics, Computer and Surveying Engineering, University West (HV), SE-461 86, Trollhättan, Sweden.
    Sjöberg, Lars E.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Fastigheter och byggande, Geodesi och satellitpositionering. Division of Mathematics, Computer and Surveying Engineering, University West (HV), SE-461 86, Trollhättan, Sweden.
    Estimating a combined Moho model for marine areas via satellite altimetric - gravity and seismic crustal models2019Ingår i: Studia Geophysica et Geodaetica, ISSN 0039-3169, E-ISSN 1573-1626Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Isostasy is a key concept in geoscience in interpreting the state of mass balance between the Earth’s lithosphere and viscous asthenosphere. A more satisfactory test of isostasy is to determine the depth to and density contrast between crust and mantle at the Moho discontinuity (Moho). Generally, the Moho can be mapped by seismic information, but the limited coverage of such data over large portions of the world (in particular at seas) and economic considerations make a combined gravimetric-seismic method a more realistic approach. The determination of a high-resolution of the Moho constituents for marine areas requires the combination of gravimetric and seismic data to diminish substantially the seismic data gaps. In this study, we estimate the Moho constituents globally for ocean regions to a resolution of 1° × 1° by applying the Vening Meinesz-Moritz method from gravimetric data and combine it with estimates derived from seismic data in a new model named COMHV19. The data files of GMG14 satellite altimetry-derived marine gravity field, the Earth2014 Earth topographic/bathymetric model, CRUST1.0 and CRUST19 crustal seismic models are used in a least-squares procedure. The numerical computations show that the Moho depths range from 7.3 km (in Kolbeinsey Ridge) to 52.6 km (in the Gulf of Bothnia) with a global average of 16.4 km and standard deviation of the order of 7.5 km. Estimated Moho density contrasts vary between 20 kg m-3 (north of Iceland) to 570 kg m-3 (in Baltic Sea), with a global average of 313.7 kg m-3 and standard deviation of the order of 77.4 kg m-3. When comparing the computed Moho depths with current knowledge of crustal structure, they are generally found to be in good agreement with other crustal models. However, in certain regions, such as oceanic spreading ridges and hot spots, we generally obtain thinner crust than proposed by other models, which is likely the result of improvements in the new model. We also see evidence for thickening of oceanic crust with increasing age. Hence, the new combined Moho model is able to image rather reliable information in most of the oceanic areas, in particular in ocean ridges, which are important features in ocean basins.

  • 18.
    Abrehdary, Majid
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Samhällsplanering och miljö, Geodesi och satellitpositionering.
    Sjöberg, Lars E.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Samhällsplanering och miljö, Geodesi och satellitpositionering.
    Bagherbandi, Mohammad
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Samhällsplanering och miljö, Geodesi och satellitpositionering. Univ Gavle, Dept Ind Dev IT & Land Management, SE-80176 Gavle, Sweden.
    Combined Moho parameters determination using CRUST1.0 and Vening Meinesz-Moritz model2015Ingår i: Journal of Earth Science, ISSN 1674-487X, E-ISSN 1867-111X, Vol. 26, nr 4, s. 607-616Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    According to Vening Meinesz-Moritz (VMM) global inverse isostatic problem, either the Moho density contrast (crust-mantle density contrast) or the Moho geometry can be estimated by solving a non-linear Fredholm integral equation of the first kind. Here solutions to the two Moho parameters are presented by combining the global geopotential model (GOCO-03S), topography (DTM2006) and a seismic crust model, the latter being the recent digital global crustal model (CRUST1.0) with a resolution of 1A(0)x1A(0). The numerical results show that the estimated Moho density contrast varies from 21 to 637 kg/m(3), with a global average of 321 kg/m(3), and the estimated Moho depth varies from 6 to 86 km with a global average of 24 km. Comparing the Moho density contrasts estimated using our leastsquares method and those derived by the CRUST1.0, CRUST2.0, and PREM models shows that our estimate agrees fairly well with CRUST1.0 model and rather poor with other models. The estimated Moho depths by our least-squares method and the CRUST1.0 model agree to 4.8 km in RMS and with the GEMMA1.0 based model to 6.3 km.

  • 19.
    Abrehdary, Majid
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Samhällsplanering och miljö, Geodesi och satellitpositionering.
    Sjöberg, Lars E.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Samhällsplanering och miljö, Geodesi och satellitpositionering.
    Bagherbandi, Mohammad
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Samhällsplanering och miljö, Geodesi och satellitpositionering.
    The spherical terrain correction and its effect on the gravimetric-isostatic Moho determination2016Ingår i: Geophysical Journal International, ISSN 0956-540X, E-ISSN 1365-246X, Vol. 204, nr 1, s. 262-273Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this study, the Moho depth is estimated based on the refined spherical Bouguer gravity disturbance and DTM2006 topographic data using the Vening Meinesz-Moritz gravimetric-isostatic hypothesis. In this context, we compute the refined spherical Bouguer gravity disturbances in a set of 1 degrees x 1 degrees blocks. The spherical terrain correction, a residual correction to each Bouguer shell, is computed using rock heights and ice sheet thicknesses from the DTM2006 and Earth2014 models. The study illustrates that the defined simple Bouguer gravity disturbance corrected for the density variations of the oceans, ice sheets and sediment basins and also the non-isostatic effects needs a significant terrain correction to become the refined Bouguer gravity disturbance, and that the isostatic gravity disturbance is significantly better defined by the latter disturbance plus a compensation attraction. Our study shows that despite the fact that the lateral variation of the crustal depth is rather smooth, the terrain affects the result most significantly in many areas. The global numerical results show that the estimated Moho depths by the simple and refined spherical Bouguer gravity disturbances and the seismic CRUST1.0 model agree to 5.6 and 2.7 km in RMS, respectively. Also, the mean value differences are 1.7 and 0.2 km, respectively. Two regional numerical studies show that the RMS differences between the Moho depths estimated based on the simple and refined spherical Bouguer gravity disturbance and that using CRUST1.0 model yield fits of 4.9 and 3.2 km in South America and yield 3.2 and 3.4 km in Fennoscandia, respectively.

  • 20.
    Abshirini, Ehsan
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Samhällsplanering och miljö, Geoinformatik.
    Koch, Daniel
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Arkitektur.
    Rivers as integration devices in cities2016Ingår i: City, Territory and Architecture, E-ISSN 2195-2701, Vol. 3, nr 1, s. 1-21Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: As dynamic systems rivers and cities have been in interaction under changing relations over time, and the morphology of many cities has risen through a long and steady struggle between the city functions and the river system flowing inside. This makes river cities an interesting case to study how the presence of geographical features interacts with spatial morphology in the formation of cities.

    Methods: The basis of this research is enabled by utilizing a novel model for cross-city comparison presented by Hillier in his Santiago keynote in 2012 called a “star model”. This is done on large samples of cities investigating concurrent configurations, as well as how the properties in this star model react to specific forms of disturbance.

    Results: Results illustrate that the foreground network as identified through maximum choice values in cities are more vital to the structure of cities than the bridges. The overall syntactic structure tends to retain its character (degree of distributedness) and the location of its foreground network (which street segments constitute the foreground network) even when bridges are targeted. Furthermore, counter to the initial hypothesis, river cities tend to change less than non-river cities after targeted disturbance of the systems. Finally, the results show that while there is a statistical morphological difference between river cities and non-river cities, this difference is not directly explained through the bridges.

    Conclusion: Integrating space syntax with statistical and geospatial analysis can throw light on the way in which the properties of city networks and urban structure reflect the relative effect of rivers on the morphology of river cities. The paper, finally, contributes through offering one piece of a better perception of the structure of river-cities that can support strategies of river-cities interaction as well as enhance our knowledge on the constraints and limits to that interaction.

    Ladda ner fulltext (pdf)
    Abshirini & Koch - Rivers as integration devices in cities
  • 21.
    Acuña, José
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Tillämpad termodynamik och kylteknik.
    Improvements of U-pipe Borehole Heat Exchangers2010Licentiatavhandling, monografi (Övrigt vetenskapligt)
    Abstract [en]

    The sales of Ground Source Heat Pumps in Sweden and many other countries are having a rapid growth in the last decade. Today, there are approximately 360 000 systems installed in Sweden, with a growing rate of about 30 000 installations per year. The most common way to exchange heat with the bedrock in ground source heat pump applications is circulating a secondary fluid through a Borehole Heat Exchanger (BHE), a closed loop in a vertical borehole. The fluid transports the heat from the ground to a certain heating and/or cooling application. A fluid with one degree higher or lower temperature coming out from the borehole may represent a 2-3% change in the COP of a heat pump system. It is therefore of great relevance to design cost effective and easy to install borehole heat exchangers. U-pipe BHEs consisting of two equal cylindrical pipes connected together at the borehole bottom have dominated the market for several years in spite of their relatively poor thermal performance and, still, there exist many uncertainties about how to optimize them. Although more efficient BHEs have been discussed for many years, the introduction of new designs has been practically lacking. However, the interest for innovation within this field is increasing nowadays and more effective methods for injecting or extracting heat into/from the ground (better BHEs) with smaller temperature differences between the heat secondary fluid and the surrounding bedrock must be suggested for introduction into the market.

    This report presents the analysis of several groundwater filled borehole heat exchangers, including standard and alternative U-pipe configurations (e.g. with spacers, grooves), as well as two coaxial designs. The study embraces measurements of borehole deviation, ground water flow, undisturbed ground temperature profile, secondary fluid and groundwater temperature variations in time, theoretical analyses with a FEM software, Distributed Thermal Response Test (DTRT), and pressure drop. Significant attention is devoted to distributed temperature measurements using optic fiber cables along the BHEs during heat extraction and heat injection from and to the ground.

    Ladda ner fulltext (pdf)
    FULLTEXT01
  • 22.
    Adem Esmail, Blal
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Samhällsplanering och miljö. Ruhr University Bochum, Institute of Geography, Universitätsstr. 150, 44805 Bochum, Germany.
    Cortinovis, Chiara
    Suleiman, Lina
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Samhällsplanering och miljö, Urbana och regionala studier.
    Albert, Christian
    Geneletti, Davide
    Mörtberg, Ulla
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Hållbar utveckling, miljövetenskap och teknik, Hållbarhet, utvärdering och styrning.
    Greening cities through urban planning: A literature review on the uptake of concepts and methods in Stockholm2022Ingår i: Urban Forestry & Urban Greening, ISSN 1618-8667, E-ISSN 1610-8167, s. 127584-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Nature-based solutions (NBS) represent the most recent of several "greening" concepts proposed to support spatial planning and decision-making towards sustainable metropolitan regions. Despite similarities, the concepts stem from different disciplines and policy arenas and reflect various models of people-nature relations. This paper aims to analyze the uptake of greening concepts in scientific planning literature focusing on (urban) nature and landscape in the metropolitan region of Stockholm, Sweden, over the last three decades. It investigates what changes this evolution has brought in terms of the topics adopted, methods applied, and types of planning support put into practice. We identified 574 articles that reflect substantial research on greening concepts in the Swedish planning context. The articles demonstrate an initial prevalence of biodiversity with later increases of interest in ecosystem services and NBS. A detailed analysis of the studies focusing on Stockholm revealed Population growth/densification, Green space management and Biodiversity conservation as the most commonly addressed societal challenges. The most frequently mentioned type of green and blue element is Parks and (semi-)natural urban green areas, including urban forests. Methods applied were mostly quantitative, while mixes with qualitative approaches were only apparent in ecosystem services articles. Half of the studies involved practitioners or decision-makers, but only four seemed related to real-life planning processes. Taken together, the influence of scientific literature on the uptake of greening concepts in spatial planning seems to have been limited. Future mainstreaming of greening concepts in Stockholm and beyond could benefit from available data, methods and experiences, but will require more active translation and boundary management. Further research into science-policy-planning interfaces at city scale is thus imperative to advance more sustainable pathways for people and nature in metropolitan regions.

  • 23.
    Adem Esmail, Blal
    et al.
    Department of Civil, Environmental, and Mechanical Engineering, University of Trento, Via Mesiano 77, Trento, 38123, Italy.
    Geneletti, Davide
    Department of Civil, Environmental, and Mechanical Engineering, University of Trento, Via Mesiano 77, 38123 Trento, Italy.
    Design and impact assessment of watershed investments: An approach based on ecosystem services and boundary work.2017Ingår i: Environmental impact assessment review, ISSN 0195-9255, E-ISSN 1873-6432, Vol. 62, s. 1-13Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Watershed investments, whose main aim is to secure water for cities, represent a promising opportunity for large-scale sustainability transitions in the near future. If properly designed, they promote activities in the watershed that enhance ecosystem services while protecting nature and biodiversity, as well as achieving other societal goals. In this paper, we build on the concepts of ecosystem services and boundary work, to develop and test an operative approach for designing and assessing the impact of watershed investments. The approach is structured to facilitate negotiations among stakeholders. Its strategic component includes setting the agenda; defining investment scenarios; and assessing the performance of watershed investments as well as planning for a follow-up. Its technical component concerns data processing; tailoring spatially explicit ecosystem service models; hence their application to design a set of “investment portfolios”, generate future land use scenarios, and model impacts on selected ecosystem services. A case study illustrates how the technical component can be developed in a data scarce context in sub-Saharan Africa in a way that is functional to support the steps of the strategic component. The case study addresses soil erosion and water scarcity-related challenges affecting Asmara, a medium-sized city in Eritrea, and considers urban water security and rural poverty alleviation as two illustrative objectives, within a ten-year planning horizon. The case study results consist in spatially explicit data (investment portfolio, land use scenario, impact on ecosystem services), which were aggregated to quantitatively assess the performance of different watershed investments scenarios, in terms of changes in soil erosion control. By addressing stakeholders' concerns of credibility, saliency, and legitimacy, the approach is expected to facilitate negotiation of objectives, definition of scenarios, and assessment of alternative watershed investments, ultimately, to contribute to implementing an adaptive watershed management.

  • 24. Adem Esmail, Blal
    et al.
    Geneletti, Davide
    Knowledge transfer and capacity building: an example from the urban water sector2018Ingår i: JUNCO Journal of Universities and international development Cooperation, ISSN 2531-8772, Vol. 1, nr 1Artikel i tidskrift (Övrigt vetenskapligt)
    Abstract [en]

    Rural-to-urban migration and sustained natural population growth in Africa, if not properly addressed, may pose serious threat to ecosystems and human wellbeing, both locally and afar. Novel concepts and operative approaches are needed to better frame these challenges and support local decision-making processes, to promote sustainable development. Indeed, this is a key area in which the Academia can make a significant contribution, for example, exploring innovative concepts and developing related approaches to support decision-making processes at a local scale. This paper focuses on the urban water sector as an informative example, ultimately aiming to highlight key areas in which research can provide concrete and valuable assistance. More specifically, we introduce two innovative concepts, i.e. ecosystem services and boundary work; hence propose an operative approach to support the process of design and assessment of the impact of watershed investments. To illustrate real-life implementation of the approach in a data scarce context in sub-Saharan Africa, we consider as a case study soil erosion and water scarcity-related challenges affecting Asmara, a medium-sized city in Eritrea. Accordingly, we adopt urban water security and rural poverty alleviation as two illustrative objectives, within a ten-year planning horizon. The case study application resulted in spatially explicit outputs that inform decision-making processes. By timely addressing stakeholders' concerns of credibility, saliency, and legitimacy, the proposed approach is expected to facilitate negotiation of objectives, definition of scenarios, and assessment of alternative watershed investments. Above all, and beyond the urban water sector, the case study application helps highlighting key areas in which the academic work can make concrete contribution mainly in terms of knowledge transfer and capacity building.

    Ladda ner fulltext (pdf)
    fulltext
  • 25.
    Adem Esmail, Blal
    et al.
    Univ Trento, Dept Civil Environm & Mech Engn, Trento, Italy..
    Geneletti, Davide
    Multi-criteria decision analysis for nature conservation: A review of 20 years of applications2018Ingår i: Methods in Ecology and Evolution, E-ISSN 2041-210X, Vol. 9, s. 42-53Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    1. Multi-criteria decision analysis (MCDA) is a method to support decision-making, by exploring the balance between the pros and cons of different alternatives to ac- complish a specific goal. It assists in framing decision problems, illustrating the per- formance of alternatives across criteria, exploring trade-offs, formulating a decision and testing its robustness. This paper provides a structured review of empirical applications of MCDA to nature conservation published in the scientific literature over the last 20 years. The paper aims at taking stock of past experiences, and comparing them with best practices and common pitfalls identified in the literature, to provide recommendations for better MCDA application to conservation.

    2. The review follows the structure of a generalized MCDA process consisting of three key stages: (1) decision context and problem structuring, (2) analysis and (3) decision.

    3. The search identified 86 papers that describe MCDA applications to a range of top- ics, including conservation prioritization and planning; protected areas management and zoning; forest management and restoration; and mapping of biodiversity, naturalness and wilder. The results show that, concerning problem structuring, a small percentage of the reviewed MCDA engaged stakeholders other than the authors in identifying alternatives and formulating criteria (15% and 35% respectively). Concerning the analysis, criteria assessment was adequately justified by the authors (47%), at times also by involving other stakeholders (22%). Weighting was per- formed in almost all applications, whereas criteria aggregation was mostly based on the weighted linear combination (63%). Sensitivity analysis was largely overlooked (57%). Concerning decision, 45% of the articles provided only an overall ranking or suitability of alternatives, while 22% included additional rankings according to spe- cific criterion, and 8% further analyses and clustering of stakeholders’ preferences.

    4. The paper concludes by suggesting key elements of successful MCDA applications, including clear construction of the decision context; collaborative identification of alternatives and criteria that reflect the values at stake; adequate justification and communication of the methods for criteria assessment and weighting; reasoned choice of the criteria aggregation method, and comprehensive sensitivity analysis.

  • 26.
    Adodoadji-Dogbe, Catherine Doe
    et al.
    SOAS, University of London, UK.
    Urban, Frauke
    KTH, Skolan för industriell teknik och management (ITM), Industriell ekonomi och organisation (Inst.), Hållbarhet, Industriell dynamik & entreprenörskap.
    Climate change, policy processes and local vulnerability2023Ingår i: Handbook on Climate Change and Technology, Edward Elgar Publishing Ltd. , 2023, s. 338-353Kapitel i bok, del av antologi (Övrigt vetenskapligt)
  • 27.
    Adodoadji-Dogbe, Catherine Doe
    et al.
    SOAS, University of London, UK.
    Urban, Frauke
    KTH, Skolan för industriell teknik och management (ITM), Industriell ekonomi och organisation (Inst.), Hållbarhet, Industriell dynamik & entreprenörskap.
    Vulnerability and adaptation to climate change in coastal fishing communities2023Ingår i: Handbook on Climate Change and Technology, Edward Elgar Publishing Ltd. , 2023, s. 373-388Kapitel i bok, del av antologi (Övrigt vetenskapligt)
  • 28.
    Adolfsson, Karin H.
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Melilli, Giuseppe
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Hakkarainen, Minna
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Polymerteknologi.
    Oxidized Carbonized Cellulose-Coated Filters for Environmental Contaminant Adsorption and Detection2020Ingår i: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 59, nr 30, s. 13578-13587Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Cationized cellulose filters with coating of oxidized carbonized cellulose (OCC) were successfully fabricated. The OCC-coated filter was demonstrated as a combined surface for adsorption of environmental contaminants and their detection on the filter by surface-assisted desorption ionization-mass spectrometry (SALDI-MS). The cellulose filters were cationized by utilizing 3-chloro-2-hydroxypropyltrimethylammonium chloride (CHTAC) and sodium hydroxide. It was shown that the degree of substitution increased with the CHTAC feed. OCC, synthesized by hydrothermal carbonization of cellulose with subsequent oxidation and dialysis, was attached onto the cationized filters by electrostatic interactions. The filters adsorbed the model contaminant methylene blue (MB) from aqueous solution, and the MB could subsequently be detected on the filter surfaces by SALDI-MS as [M](+) adduct. The OCC coating further improved the relative peak intensity of [M](+) with little background interferences. This work indicates great potential for the OCC-coated filters as a combined surface for rapid monitoring of environmental contaminants.

  • 29. Agarwal, S.
    et al.
    Wettlaufer, J. S.
    KTH, Centra, Nordic Institute for Theoretical Physics NORDITA. Yale University, New Haven, CT, USA; Mathematical Institute, University of Oxford, Oxford, UK.
    Fluctuations in Arctic sea-ice extent: Comparing observations and climate models2018Ingår i: Philosophical Transactions. Series A: Mathematical, physical, and engineering science, ISSN 1364-503X, E-ISSN 1471-2962, Vol. 376, nr 2129, artikel-id 20170332Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The fluctuation statistics of the observed sea-ice extent during the satellite era are compared with model output from CMIP5 models using a multifractal time series method. The two robust features of the observations are that on annual to biannual time scales the ice extent exhibits white noise structure, and there is a decadal scale trend associated with the decay of the ice cover. It is shown that (i) there is a large inter-model variability in the time scales extracted from the models, (ii) none of the models exhibits the decadal time scales found in the satellite observations, (iii) five of the 21 models examined exhibit the observed white noise structure, and (iv) the multi-model ensemble mean exhibits neither the observed white noise structure nor the observed decadal trend. It is proposed that the observed fluctuation statistics produced by this method serve as an appropriate test bed for modelling studies. 

  • 30. Agarwal, Sahil
    et al.
    Wettlaufer, John S.
    KTH, Centra, Nordic Institute for Theoretical Physics NORDITA. Yale University, United States; University of Oxford, United Kingdom.
    The Statistical Properties of Sea Ice Velocity Fields2017Ingår i: Journal of Climate, ISSN 0894-8755, E-ISSN 1520-0442, Vol. 30, nr 13, s. 4873-4881Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    By arguing that the surface pressure field over the Arctic Ocean can be treated as an isotropic, stationary, homogeneous, Gaussian random field, Thorndike estimated a number of covariance functions from two years of data (1979 and 1980). Given the active interest in changes of general circulation quantities and indices in the polar regions during the recent few decades, the spatial correlations in sea ice velocity fields are of particular interest. It is thus natural to ask, "How persistent are these correlations?'' To this end, a multifractal stochastic treatment is developed to analyze observed Arctic sea ice velocity fields from satellites and buoys for the period 1978-2015. Since it was previously found that the Arctic equivalent ice extent (EIE) has a white noise structure on annual to biannual time scales, the connection between EIE and ice motion is assessed. The long-term stationarity of the spatial correlation structure of the velocity fields and the robustness of their white noise structure on multiple time scales is demonstrated; these factors (i) combine to explain the white noise characteristics of the EIE on annual to biannual time scales and (ii) explain why the fluctuations in the ice velocity are proportional to fluctuations in the geostrophic winds on time scales of days to months. Moreover, it is shown that the statistical structure of these two quantities is commensurate from days to years, which may be related to the increasing prevalence of free drift in the ice pack.

  • 31.
    Agha Karimi, Armin
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Fastigheter och byggande, Geodesi och satellitpositionering.
    Internal Variability Role on Estimating Sea Level Acceleration in Fremantle Tide Gauge Station2021Ingår i: Frontiers in Earth Science, E-ISSN 2296-6463, Vol. 9, artikel-id 664947Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Low frequency internal signals bring challenges to signify the role of anthropogenic factors in sea level rise and to attain a certain accuracy in trend and acceleration estimations. Due to both spatially and temporally poor coverage of the relevant data sets, identification of internal variability patterns is not straightforward. In this study, the identification and the role of low frequency internal variability (decadal and multidecadal) in sea level change of Fremantle tide gauge station is analyzed using two climate indices, Pacific Decadal Oscillation (PDO) and Tripole Interdecadal Pacific Oscillation (TPI). It is shown that the multidecadal sea level variability is anticorrelated with corresponding components of climate indices in the Pacific Ocean, with correlation coefficients of -0.9 and -0.76 for TPI and PDO, respectively. The correlations are comparatively low on decadal time scale, -0.5 for both indices. This shows that internal variability on decadal and multidecadal scales affects the sea level variation in Fremantle unequally and thus, separate terms are required in trajectory models. To estimate trend and acceleration in Fremantle, three trajectory models are tested. The first model is a simple second-degree polynomial comprising trend and acceleration terms. Low passed PDO, representing decadal and interdecadal variabilities in Pacific Ocean, added to the first model to form the second model. For the third model, decomposed signals of decadal and multidecadal variability of TPI are added to the first model. In overall, TPI represents the low frequency internal variability slightly better than PDO for sea level variation in Fremantle. Although the estimated trends do not change significantly, the estimated accelerations varies for the three models. The accelerations estimated from the first and second models are statistically insignificant, 0.006 +/- 0.012 mm yr(-2) and 0.01 +/- 0.01 mm yr(-2), respectively, while this figure for the third model is 0.018 +/- 0.011 mm yr(-2). The outcome exemplifies the importance of modelling low frequency internal variability in acceleration estimations for sea level rise in regional scale.

  • 32.
    Agha Karimi, Armin
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Fastigheter och byggande, Geodesi och satellitpositionering.
    Bagherbandi, Mohammad
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Fastigheter och byggande, Geodesi och satellitpositionering. Univ Gävle, Fac Engn & Sustainable Dev, Gävle, Sweden..
    Horemuz, Milan
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Fastigheter och byggande, Geodesi och satellitpositionering.
    Multidecadal Sea Level Variability in the Baltic Sea and Its Impact on Acceleration Estimations2021Ingår i: Frontiers in Marine Science, E-ISSN 2296-7745, Vol. 8Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Multidecadal sea level variation in the Baltic Sea is investigated from 1900 to 2020 deploying satellite and in situ datasets. As a part of this investigation, nearly 30 years of satellite altimetry data are used to compare with tide gauge data in terms of linear trend. This, in turn, leads to validation of the regional uplift model developed for the Fennoscandia. The role of North Atlantic Oscillation (NAO) in multidecadal variations of the Baltic Sea is also analyzed. Although NAO impacts the Baltic Sea level on seasonal to decadal time scales according to previous studies, it is not a pronounced factor in the multidecadal variations. The acceleration in the sea level rise of the basin is reported as statistically insignificant in recent studies or even decelerating in an investigation of the early 1990s. It is shown that the reason for these results relates to the global warming hiatus in the 1950s-1970s, which can be seen in all eight tide gauges used for this study. To account for the slowdown period, the acceleration in the basin is investigated by fitting linear trends to time spans of six to seven decades, which include the hiatus. These results imply that the sea level rise is accelerated in the Baltic Sea during the period 1900-2020.

  • 33.
    Agha Karimi, Armin
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Fastigheter och byggande, Geodesi och satellitpositionering.
    Ghobadi-Far, Khosro
    Department of Geosciences, Virginia Tech, Blacksburg, VA, United States.
    Passaro, Marcello
    Deutsches Geodätisches Forschungsinstitut der Technischen Universität München, Munich, Germany.
    Barystatic and steric sea level variations in the Baltic Sea and implications of water exchange with the North Sea in the satellite era2022Ingår i: Frontiers in Marine Science, E-ISSN 2296-7745, Vol. 9, artikel-id 963564Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Satellite altimetry, satellite gravimetry, and in-situ subsurface salinity and temperature profiles are used to investigate the total, barystatic, and steric sea level variations in the Baltic Sea, respectively. To estimate the steric sea level, the density variations are weighted in deeper layers to prevent overestimation of their contribution. We show that the sum of barystatic and steric components exhibits excellent cross correlation (0.9) with satellite altimetry sea level variations and also explains up to 84% of total signal variability from 2002 to 2019. Considering the dominance of barystatic sea level variations in the basin and the limitation of satellite gravimetry in resolving the mass change in water-land transition zones (known as the leakage problem), the mismatch is likely attributed to the inadequate accuracy of the barystatic datasets. The total sea level and its contributors are further decomposed into seasonal, interannual, and decadal temporal components. It is shown that despite its insignificant contributions to seasonal and interannual changes, the steric sea level plays an important role in decadal variations. Additionally, we show that the interannual variations of the barystatic sea level are governed by the North Atlantic Oscillation in the basin. The sea level variation in the North Sea is also examined to deduce the water exchange patterns on different time scales. A drop in the North Sea level can be seen from 2005 to 2011 which is followed by the Baltic Sea level with a ~3-year lag, implying the outflow from the Baltic Sea to the North Sea.

  • 34.
    Aguilar, Mónica García
    et al.
    Swedish University of Agricultural Sciences, Department of Urban and Rural Development.
    Jaramillo, Juan Felipe
    Universidad El Bosque.
    Ddiba, Daniel
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Hållbar utveckling, miljövetenskap och teknik, Hållbarhet, utvärdering och styrning. Stockholm Environment Institute.
    Páez, Diana Carolina
    Universidad El Bosque.
    Rueda, Hector
    Universidad El Bosque.
    Andersson, Kim
    Stockholm Environment Institute.
    Dickin, Sarah
    Stockholm Environment Institute.
    Governance challenges and opportunities for implementing resource recovery from organic waste streams in urban areas of Latin America: insights from Chía, Colombia2022Ingår i: Sustainable Production and Consumption, ISSN 2352-5509, Vol. 30, s. 53-63Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Across the globe, there is increasing interest in implementing circular approaches to urban sanitation and waste management to mitigate environmental challenges and promote sustainable business opportunities. In Latin America where 80% of the population live in urban areas, there is limited investigation into the enabling factors and governance barriers that are critical to implementing circular economy strategies in urban areas. This paper aims at assessing the governance capacity to implement resource recovery from organic waste streams in the municipality of Chía, Colombia, through applying the Governance Capacity Framework in a participatory process with local stakeholders. The findings highlight the importance of local initiatives for resource recovery that allow experimentation, raise awareness and foster collaboration, as well as mechanisms available for public participation in decision-making processes as enabling factors. Meanwhile, the inadequate monitoring and assessment of environmental strategies and policies, inadequate sharing of information among stakeholders and the relative low awareness of potential benefits of recovering resources from organic waste streams, especially among public sector actors, emerge as key barriers. Beyond Chía, the results provide insights on crucial factors for ensuring sufficient governance capacity in other urban areas in low- and middle-income countries which are considering circular approaches to urban sanitation and waste management. The findings also provide an empirical basis to advance the understanding of the governance conditions necessary for implementing resource recovery from organic waste streams, upon which further applications of the governance capacity framework along with participatory aspects in other similar urban contexts could build.

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  • 35.
    Ahlberg, Jesper
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Mark- och vattenteknik, Biogeofysik.
    Gustafsson, David
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Mark- och vattenteknik, Biogeofysik.
    Distributed snow modelling integrating ground penetrating radar data for improved runoff predictions in a Swedish mountain basin2009Ingår i: EGU General Assembly 2009, 2009Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    Operational forecasts of snow melt runoff in Sweden are currently running with precipitation and temperature as the main input variables and calibrated with runoff data, and there is an interest to make better use of new measurement systems for distributed snow data. At the same time, various data assimilation techniques are becoming more frequently used in hydrological modeling, in order to reduce uncertainties related to both model structure errors and errors in input and calibration data. Thus, it is important to address not only what type of snow data that can be used to improve the model predictions, but also what type of input data and model structures that are optimal in relation to the available snow data. The objective of this study is to investigate to what extent the runoff predictions can be improved by assimilation of temporal and spatially distributed snow data, and if the improvements depend on the choice of model structures, for instance the use of energy balance or day-degree snow models. In order to achieve these objectives a new distributed snow model has been implemented into the hydrological modeling framework HYSS/HYPE. This model can easily be setup with either an energy balance model or a day-degree model for the snow pack calculations, and it is easy to run the model with different spatial resolutions. In the fully distributed case, snow drift processes are implicitly included in the model through a precipitation distribution model, based on topographical information and wind direction. The model was applied to a mountain basin in northern Sweden used for hydropower production, where extensive snow measurements were taken during the last two winters 2007-2009. A climate station is located at the outlet of the regulation lake, including automated point measurements of snow depth, snow mass (snow pillow), snow wetness and snow temperature. Distributed snow cover data was sampled using ground-penetrating radar from snow mobiles. Measurements were taken at the time of the maximum snow cover, providing a data set with snow depth, snow density, snow water equivalent along 20 km long transects in representative areas of the basin. The precipitation distribution model was calibrated using the distributed SWE data from the GPR measurements. Application of the calibrated model to previous years without available snow data show that the runoff predictions was improved compared to calibrations without the distributed snow data, however the improvements were larger for the energy balance compared to the day-degree model. Further developments will include assimilation of the temporal and spatial snow data to adjust the distribution of various input variables, for instance air temperature and wind speed.

  • 36.
    Ahlberg, Jesper
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Mark- och vattenteknik, Biogeofysik.
    Gustafsson, David
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Mark- och vattenteknik, Biogeofysik.
    Snow melt runoff simulations using ensemble Kalman filter assimilation of distributed snow data2010Konferensbidrag (Övrigt vetenskapligt)
  • 37.
    Ahlgren, Serina
    et al.
    SLU.
    Björklund, Anna
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Hållbar utveckling, miljövetenskap och teknik, Miljöstrategisk analys (fms).
    Ekman, Anna
    Lund University.
    Karlsson, H
    SLU.
    Berlin, Johanna
    SP.
    Börjesson, Pål
    Lund University.
    Ekvall, Tomas
    IVL.
    Finnveden, Göran
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Hållbar utveckling, miljövetenskap och teknik, Miljöstrategisk analys (fms).
    Janssen, Matty
    Chalmers.
    Strid, Ingrid
    SLU.
    LCA of biorefinieries -identification of key issues and methodological recommendations2013Rapport (Övrigt vetenskapligt)
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  • 38.
    Ahlgren, Serina
    et al.
    Swedish University of Agricultural Sciences.
    Björklund, Anna
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Hållbar utveckling, miljövetenskap och teknik, Miljöstrategisk analys (fms).
    Ekman, Anna
    SP Technical Research Institute of Sweden.
    Karlsson, Hanna
    Swedish University of Agricultural Sciences.
    Berlin, Johanna
    SP Technical Research Institute of Sweden.
    Börjesson, Pål
    Lund University.
    Ekvall, Tomas
    IVL Swedish Environmental Research Institute.
    Finnveden, Göran
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Hållbar utveckling, miljövetenskap och teknik, Miljöstrategisk analys (fms).
    Janssen, Matty
    Chalmers University of Technology.
    Strid, Ingrid
    Swedish University of Agricultural Sciences.
    Review of methodological choices in LCA of biorefinery systems: key issues and recommendations2015Ingår i: Biofuels, Bioproducts and Biorefining, ISSN 1932-104X, E-ISSN 1932-1031, Vol. 9, nr 5, s. 606-619Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The current trend in biomass conversion technologies is toward more efficient utilization of biomass feedstock in multiproduct biorefineries. Many life-cycle assessment (LCA) studies of biorefinery systems have been performed but differ in how they use the LCA methodology. Based on a review of existing LCA standards and guidelines, this paper provides recommendations on how to handle key methodological issues when performing LCA studies of biorefinery systems. Six key issues were identified: (i) goal definition, (ii) functional unit, (iii) allocation of biorefinery outputs, (iv) allocation of biomass feedstock, (v) land use, and (vi) biogenic carbon and timing of emissions. Many of the standards and guidelines reviewed here provide only general methodological recommendations. Some make more specific methodological recommendations, but these often differ between standards. In this paper we present some clarifications (e.g. examples of research questions and suitable functional units) and methodological recommendations (e.g. on allocation).

  • 39.
    Ahlmér, Anna Klara
    et al.
    Trivector Traff, Stockholm, Sweden.
    Cavalli, Marco
    CNR, Res Inst Geohydrol Protect, Padua, Italy..
    Hansson, Klas
    Swedish Transport Adm Trafikverket, S-17290 Stockholm, Sweden..
    Koutsouris, Alexander J.
    Stockholm Univ, Dept Phys Geog, S-10691 Stockholm, Sweden..
    Crema, Stefano
    CNR, Res Inst Geohydrol Protect, Padua, Italy..
    Kalantari, Zahra
    Stockholm Univ, Dept Phys Geog, S-10691 Stockholm, Sweden.;Stockholm Univ, Bolin Ctr Climate Res, S-10691 Stockholm, Sweden..
    Soil moisture remote-sensing applications for identification of flood-prone areas along transport infrastructure2018Ingår i: Environmental Earth Sciences, ISSN 1866-6280, E-ISSN 1866-6299, Vol. 77, nr 14, artikel-id 533Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The expected increase in precipitation and temperature in Scandinavia, and especially short-time heavy precipitation, will increase the frequency of flooding. Urban areas are the most vulnerable, and specifically, the road infrastructure. The accumulation of large volumes of water and sediments on road-stream intersections gets severe consequences for the road drainage structures. This study integrates the spatial and temporal soil moisture properties into the research about flood prediction methods by a case study of two areas in Sweden, Vastra Gotaland and Varmland, which was affected by severe flooding in August 2014. Soil moisture data are derived from remote-sensing techniques, with a focus on the soil moisture-specific satellites ASCAT and SMOS. Furthermore, several physical catchments descriptors (PCDs) are analyzed and the result shows that larger slopes and drainage density, in general, mean a higher risk of flooding. The precipitation is the same; however, it can be concluded that more precipitation in most cases gives higher soil moisture values. The lack, or the dimensioning, of road drainage structures seems to have a large impact on the flood risk as more sediment and water can be accumulated at the road-stream intersection. The results show that the method implementing soil moisture satellite data is promising for improving the reliability of flooding.

  • 40.
    Ahmad, A.
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Hållbar utveckling, miljövetenskap och teknik. KWR Water Cycle Research Institute, Nieuwegein, Netherlands; Department of Environmental Technology, Wageningen University and Research (WUR), Wageningen, Netherlands.
    van Mook, J.
    Schaaf, B.
    van der Wal, A.
    Arsenic removal to <1 µg l−1 by coprecipitation with in-situ generated Fe(III) precipitates with and without advanced pre-oxidation2018Ingår i: Environmental Arsenic in a ChangingWorld - 7th International Congress and Exhibition Arsenic in the Environment, 2018, CRC Press/Balkema , 2018, s. 591-592Konferensbidrag (Refereegranskat)
    Abstract [en]

    The aim of this study is to investigate removal of low As concentrations from groundwater at a Drinking Water Treatment Plant (DWTP) in The Netherlands in order to achieve &lt;1 µg L−1 As in produced drinking water. Two iron based emerging technologies, both relying on in-situ generated Fe(III) precipitates for As adsorption, were investigated. These include: 1) Advanced Oxidation-Coprecipitation-Filtration (AOCF) and 2) Coprecipitation prior to ultrafiltration (C-UF). We show that most of the As removal occurs in the top half of a Rapid Sand Filter (RSF) bed. In this part we also observe the conversion of As(III) into As(V). The mechanism of As(III) oxidation to As(V) in the RSF is still not understood, however we hypothesize that either the manganese oxides or the biological activity in the filter bed may be responsible for this conversion. In agreement with this observation, we also notice that drinking water only contains As(V) and that the levels of As(III) are negligible. The experiments have shown that both AOCF and C-UF are promising emerging technologies to reduce arsenic levels to below 1 µg L−1 which is the agreed target in The Netherlands between the Dutch water companies. 

  • 41.
    Ahmad, Arslan
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Hållbar utveckling, miljövetenskap och teknik.
    Bhattacharya, Prosun
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Hållbar utveckling, miljövetenskap och teknik, Vatten- och miljöteknik.
    Arsenic in Drinking Water: Is 10 μg/L a Safe Limit?2019Ingår i: Current Pollution Reports, ISSN 2198-6592, Vol. 5, nr 1Artikel i tidskrift (Refereegranskat)
  • 42.
    Ahmad, Arslan
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Hållbar utveckling, miljövetenskap och teknik, Vatten- och miljöteknik. SIBELCO Ankerpoort NV, Op Bos 300, NL-6223 EP Maastricht, Netherlands.;Wageningen Univ & Res WUR, Dept Environm Technol, Droevendaalsesteeg 4, NL-6708 PB Wageningen, Netherlands..
    Bhattacharya, Prosun
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Hållbar utveckling, miljövetenskap och teknik, Vatten- och miljöteknik.
    Global Groundwater: Source, Scarcity, Security and Solutions2021Ingår i: Groundwater for Sustainable Development, ISSN 2352-801X, Vol. 15, artikel-id 100605Artikel, recension (Övrigt vetenskapligt)
  • 43.
    Ahmad, Arslan
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Hållbar utveckling, miljövetenskap och teknik, Hållbarhet och miljöteknik. KWR Water Cycle Res Inst, Nieuwegein, Netherlands.;WUR, Dept Environm Technol, Wageningen, Netherlands..
    Cornelissen, Emile
    KWR Water Cycle Res Inst, Nieuwegein, Netherlands.;Nanyang Technol Univ, Nanyang Environm & Water Res Inst, Singapore Membrane Technol Ctr, Singapore, Singapore.;Univ Ghent, Particle & Interfacial Technol Grp, Ghent, Belgium..
    van de Wetering, Stephan
    Brabant Water NV Breda, Breda, Netherlands..
    van Dijk, Tim
    Brabant Water NV Breda, Breda, Netherlands..
    van Genuchten, Case
    Univ Utrecht, Fac Geosci, Dept Earth Sci Geochem, Utrecht, Netherlands..
    Bundschuh, Jochen
    Univ Southern Queensland, Int Ctr Appl Climate Sci, West St, Toowoomba, Qld, Australia.;Univ Southern Queensland, Deputy Vice Chancellors Off Res & Innovat, Toowoomba, Qld, Australia.;Univ Southern Queensland, Fac Hlth Engn & Sci, Toowoomba, Qld, Australia..
    van der Wal, Albert
    WUR, Dept Environm Technol, Wageningen, Netherlands.;Evides Water Co NV Rotterdam, Rotterdam, Netherlands..
    Bhattacharya, Prosun
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Hållbar utveckling, miljövetenskap och teknik. Univ Southern Queensland, Int Ctr Appl Climate Sci, West St, Toowoomba, Qld, Australia..
    Arsenite removal in groundwater treatment plants by sequential Permanganate-Ferric treatment2018Ingår i: Journal of Water Process Engineering, E-ISSN 2214-7144, Vol. 26, s. 221-229Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The Dutch drinking water sector is actively investigating methods to reduce arsenic (As) to < 1 mu g/L in drinking water supply. We investigated (1) the effectiveness of sequential permanganate (MnO4-)-ferric (Fe(III)) dosing during aeration-rapid sand filtration to achieve < 1 mu g/L As (2) the influence of MnO4--Fe(III) dosing on preestablished removal patterns of As(III), Fe(II), Mn(II) and NH4+ in rapid sand filters and (3) the influence of MnO4--Fe(III) dosing on the settling and molecular-scale structural properties of the filter backwash solids. We report that MnO4--Fe(III) dosing is an effective technique to improve arsenite [As(III)] removal at groundwater treatment plants. At a typical aeration-rapid sand filtration facility in the Netherlands effluent As concentrations of < 1 mu g/L were achieved with 1.2 mg/L MnO4--and 1.8 mg/L Fe(III). The optimized combination of MnO4-and Fe(III) doses did not affect the removal efficiency of Fe(II), Mn(II) and NH4+ in rapid sand filters, however, the removal patterns of Fe(II) and Mn(II) in rapid sand filter were altered, as well as the settling behaviour of backwash solids. The characterization of backwash solids by Fe K-edge X-ray absorption spectroscopy (XAS) and X-ray diffraction (XRD) showed that the changed settling velocity of backwash solids with MnO4-Fe(III) in place was not due to changes in the molecular-scale structure of Fe-precipitates that constitute the major portion of the backwash solids.

  • 44.
    Ahmad, Arslan
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Hållbar utveckling, miljövetenskap och teknik. Hoofd Ingenieursbureau, Brabant Water N.V., 's-Hertogenbosch, Netherlands .
    Van De Wetering, S.
    Groenendijk, M.
    Bhattacharya, Prosun
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Hållbar utveckling, miljövetenskap och teknik.
    Advanced Oxidation-Coagulation-Filtration (AOCF) - An innovative treatment technology for targeting drinking water with <1 μg/L of arsenic2014Ingår i: One Century of the Discovery of Arsenicosis in Latin America (1914-2014): As 2014 - Proceedings of the 5th International Congress on Arsenic in the Environment, CRC Press, 2014, s. 817-819Konferensbidrag (Refereegranskat)
    Abstract [en]

    Advanced Oxidation-Coagulation-Filtration (AOCF) has been investigated for producing drinking water with less than 1 μg L-1 of As through a series of bench scale and pilot scale experiments. At bench scale, the suitable coagulant, its combination dose with KMnO4 oxidant, the optimum process pH and kinetics of As removal were determined. The optimized AOCF technique was capable of consistently reducing the As concentration to below 1 μg L-1 when implemented at pilot scale and did not adversely affect the already existing removal processes of Fe, Mn and NH4 +. Dual media filter solved the filter run time reduction issue.

  • 45.
    Ahmad, Arslan
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Hållbar utveckling, miljövetenskap och teknik. KWR Water Cycle Res Inst, Nieuwegein, Netherlands.;WUR, Dept Environm Technol, Wageningen, Netherlands.;Evides Water Co NV, Rotterdam, Netherlands..
    van der Wal, Albert
    WUR, Dept Environm Technol, Wageningen, Netherlands.;Evides Water Co NV, Rotterdam, Netherlands..
    Bhattacharya, Prosun
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Hållbar utveckling, miljövetenskap och teknik. Univ Southern Queensland, Int Ctr Appl Climate Sci, Toowoomba, Qld, Australia..
    van Genuchten, Case M.
    Geol Survey Denmark & Greenland GEUS, Geochem Dept, Copenhagen, Denmark.;Univ Utrecht, Fac Geosci, Dept Earth Sci Geochem, Utrecht, Netherlands..
    Characteristics of Fe and Mn bearing precipitates generated by Fe(II) and Mn(II) co-oxidation with O-2, MnO4 and HOCl in the presence of groundwater ions2019Ingår i: Water Research, ISSN 0043-1354, E-ISSN 1879-2448, Vol. 161, s. 505-516Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this work, we combined macroscopic measurements of precipitate aggregation and chemical composition (Mn/Fe solids ratio) with Fe and Mn K-edge X-ray absorption spectroscopy to investigate the solids formed by co-oxidation of Fe(II) and Mn(II) with O-2, MnO4, and HOCl in the presence of groundwater ions. In the absence of the strongly sorbing oxyanions, phosphate (P) and silicate (Si), and calcium (Ca), O-2 and HOCl produced suspensions that aggregated rapidly, whereas co-oxidation of Fe(II) and Mn(II) by MnO4 generated colloidally stable suspensions. The aggregation of all suspensions decreased in P and Si solutions, but Ca counteracted these oxyanion effects. The speciation of oxidized Fe and Mn in the absence of P and Si also depended on the oxidant, with O-2 producing Mn(III)-incorporated lepidocrocite (Mn/Fe = 0.01-0.02 mol/mol), HOCl producing Mn(III)-incorporated hydrous ferric oxide (HFO) (Mn/Fe = 0.08 mol/mol), and MnO4 producing poorly-ordered MnO2 and HFO (Mn/Fe > 0.5 mol/mol). In general, the presence of P and Si decreased the crystallinity of the Fe(III) phase and increased the Mn/Fe solids ratio, which was found by Mn K-edge XAS analysis to be due to an increase in surface-bound Mn(II). By contrast, Ca decreased the Mn/Fe solids ratio and decreased the fraction of Mn(II) associated with the solids, suggesting that Ca and Mn(II) compete for sorption sites. Based on these results, we discuss strategies to optimize the design (i.e. filter bed operation and chemical dosing) of water treatment plants that aim to remove Fe(II) and Mn(II) by co-oxidation.

  • 46.
    Ahmad, Arslan
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Hållbar utveckling, miljövetenskap och teknik. Department of Environmental Technology, Wageningen University and Research (WUR), Wageningen, Netherlands.
    van der Wens, Patrick
    Brabant Water NV Breda, Breda, Netherlands..
    Baken, Kirsten
    KWR Water Cycle Res Inst, Groningenhaven 7, NL-3433 PE Nieuwegein, Netherlands..
    de Waal, Luuk
    KWR Water Cycle Res Inst, Groningenhaven 7, NL-3433 PE Nieuwegein, Netherlands..
    Bhattacharya, Prosun
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Hållbar utveckling, miljövetenskap och teknik.
    Stuyfzand, Pieter
    KWR Water Cycle Res Inst, Groningenhaven 7, NL-3433 PE Nieuwegein, Netherlands.;Delft Univ Technol, Dept Geosci & Engn, Delft, Netherlands..
    Arsenic reduction to < 1 mu g/L in Dutch drinking water2020Ingår i: Environment International, ISSN 0160-4120, E-ISSN 1873-6750, Vol. 134, artikel-id 105253Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    Arsenic (As) is a highly toxic element which naturally occurs in drinking water. In spite of substantial evidence on the association between many illnesses and chronic consumption of As, there is still a considerable uncertainty about the health risks due to low As concentrations in drinking water. In the Netherlands, drinking water companies aim to supply water with As concentration of < 1 mu g/L - a water quality goal which is tenfold more stringent than the current WHO guideline. This paper provides (i) an account on the assessed lung cancer risk for the Dutch population due to pertinent low-level As in drinking water and cost-comparison between health care provision and As removal from water, (ii) an overview of As occurrence and mobility in drinking water sources and water treatment systems in the Netherlands and (iii) insights into As removal methods that have been employed or under investigation to achieve As reduction to < 1 mu g/L at Dutch water treatment plants. Lowering of the average As concentration to < 1 mu g/L in the Netherlands is shown to result in an annual benefit of 7.2-14 M(sic). This study has a global significance for setting drinking water As limits and provision of safe drinking water.

  • 47.
    Ahmad, Nawaz
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Vattendragsteknik. Policy Wing, Ministry of Petroleum and Natural Resources, Government of Pakistan, Pakistan.
    Wörman, Anders
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Vattendragsteknik.
    Bottacin-Busolin, Andrea
    Sanchez-Vila, Xavier
    Reactive transport modeling of leaking CO2-saturated brine along a fractured pathway2015Ingår i: International Journal of Greenhouse Gas Control, ISSN 1750-5836, E-ISSN 1878-0148, Vol. 42, s. 672-689Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    One concern regarding the underground storage of carbon dioxide (CO2) is its potential leakage from reservoirs. Over short period of time, the leakage risk is related mainly to CO2 as a separate supercritical fluid phase. However, over longer periods upon complete dissolution of injected CO2 in the fluid, the leakage risk is associated with dissolved phase CO2. Over the geological time scales, large-scale groundwater motion may cause displacement of brine containing dissolved CO2 along the conducting pathways. In this paper, we present a comprehensive modeling framework that describes the reactive transport of CO2-saturated brine along a fracture in the clay caprock based on the future, hypothetical leakage of the dissolved phase CO2. This study shows that the transport of leaked dissolved CO2 is significantly retarded by a combination of various physical and geochemical processes, such as mass exchange between conducting fracture and the neighboring rock matrix through molecular diffusion, sorption and calcite dissolution in the rock matrix. Mass stored in aqueous and adsorbed states in the rock matrix caused retention of dissolved CO2 along the leakage pathway. Calcite dissolution reaction in the rock matrix resulted in consumption of leaking dissolved CO2 and reduced its mass along the leakage pathway. Consumption and retention of dissolved CO2 along the leakage pathway have important implications for analyzing the potential reduction of CO2 fluxes from storage reservoirs over large periods and long travel pathways.

  • 48.
    Ahmad, Nawaz
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Vattendragsteknik. Ministry of Petroleum and Natural Resources, Pakistan.
    Wörman, Anders
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Vattendragsteknik.
    Sanchez-Vila, X.
    Jarsjö, J.
    Bottacin-Busolin, A.
    Hellevang, H.
    Injection of CO2-saturated brine in geological reservoir: A way to enhanced storage safety2016Ingår i: International Journal of Greenhouse Gas Control, ISSN 1750-5836, E-ISSN 1878-0148, Vol. 54, s. 129-144Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Injection of free-phase supercritical CO2 into deep geological reservoirs is associated with risk of considerable return flows towards the land surface due to the buoyancy of CO2, which is lighter than the resident brine in the reservoir. Such upward movements can be avoided if CO2 is injected in the dissolved phase (CO2aq). In this work, injection of CO2-saturated brine in a subsurface carbonate reservoir was modelled. Physical and geochemical interactions of injected low-pH CO2-saturated brine with the carbonate minerals (calcite, dolomite and siderite) were investigated in the reactive transport modelling. CO2-saturated brine, being low in pH, showed high reactivity with the reservoir minerals, resulting in a significant mineral dissolution and CO2 conversion in reactions. Over the injection period of 10 yr, up to 16% of the injected CO2 was found consumed in geochemical reactions. Sorption included in the transport analysis resulted in additional quantities of CO2 mass stored. However, for the considered carbonate minerals, the consumption of injected CO2aq was found mainly in the form of ionic trapping.

  • 49.
    Ahmed, Firoz
    et al.
    Noakhali Sci & Technol Univ, Dept Microbiol, Noakhali 3814, Bangladesh..
    Islam, Md Aminul
    Noakhali Sci & Technol Univ, Dept Microbiol, Noakhali 3814, Bangladesh..
    Kumar, Manish
    Indian Inst Technol, Discipline Earth Sci, Gandhinagar 382355, Gujarat, India..
    Hossain, Maqsud
    North South Univ, NSU Genome Res Inst NGRI, Dept Biochem & Microbiol, Dhaka 1229, Bangladesh..
    Bhattacharya, Prosun
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Hållbar utveckling, miljövetenskap och teknik.
    Islam, MD Tahmidul
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Hållbar utveckling, miljövetenskap och teknik.
    Hossen, Foysal
    Noakhali Sci & Technol Univ, Dept Microbiol, Noakhali 3814, Bangladesh..
    Hossain, Md Shahadat
    Noakhali Sci & Technol Univ, Dept Biotechnol & Genet Engn, Noakhali 3814, Bangladesh..
    Islam, Md Sydul
    Noakhali Sci & Technol Univ, Dept Appl Chem & Chem Engn, Noakhali 3814, Bangladesh..
    Uddin, Md Main
    Noakhali Sci & Technol Univ, Dept Biotechnol & Genet Engn, Noakhali 3814, Bangladesh..
    Islam, Md Nur
    Noakhali Sci & Technol Univ, Dept Biotechnol & Genet Engn, Noakhali 3814, Bangladesh..
    Bahadur, Newaz Mohammed
    Noakhali Sci & Technol Univ, Dept Appl Chem & Chem Engn, Noakhali 3814, Bangladesh..
    Didar-Ul-Alam, Md
    Noakhali Sci & Technol Univ, Noakhali 3814, Bangladesh..
    Reza, Hasan Mahmud
    North South Univ, Dept Pharmaceut Sci, Dhaka 1229, Bangladesh..
    Jakariya, Md
    North South Univ, Dept Environm Sci & Management, Dhaka 1229, Bangladesh..
    First detection of SARS-CoV-2 genetic material in the vicinity of COVID-19 isolation Centre in Bangladesh: Variation along the sewer network2021Ingår i: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 776, artikel-id 145724Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We made the first and successful attempt to detect SARS-CoV-2 genetic material in the vicinity wastewaters of an isolation centre i.e. Shaheed Bhulu Stadium, situated at Noakhali, Southeastern Bangladesh. Owing to the fact that isolation centre, in general, always contained a constant number of 200 COVID-19 patients, the prime objective of the study was to check if several drains carrying RNA of coronavirus are actually getting diluted or accumulated along with the sewage network. Our finding suggested that while the temporal variation of the genetic load decreased in small drains over the span of 50 days, the main sewer exhibited accumulation of SARS-CoV-2 RNA. Other interesting finding displays that probably distance of sampling location in meters is not likely to have a significant impact on the detected gene concentration, although the quantity of the RNA extracted in the downstream of the drain was higher. These findings are of immense value from the perspective of wastewater surveillance of COVID-19, as they largely imply that we do not need to monitor every wastewater system, and probably major drains monitoring may illustrate the city health. Perhaps, we are reporting the accumulation of SARS-CoV-2 genetic material along with the sewer network i.e. from primary to tertiary drains. The study sought further data collection in this line to simulate conditions prevailed in most of the developing countries and to shed further light on decay/accumulation processes of the genetic load of the SARS-COV-2.

  • 50. Ahmed, K. M.
    et al.
    Bhattacharya, Prosun
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Hållbar utveckling, miljövetenskap och teknik.
    Groundwater arsenic mitigation in Bangladesh: Two decades of advancements in scientific research and policy instruments2014Ingår i: One Century of the Discovery of Arsenicosis in Latin America (1914-2014): As 2014 - Proceedings of the 5th International Congress on Arsenic in the Environment, 2014, s. 886-888Konferensbidrag (Refereegranskat)
    Abstract [en]

    Two decades have passed since the first detection of arsenic above allowable limits in groundwater of Bangladesh. A good number of scientific research and mitigation projects have so far been completed but still today more than 22 million people are exposed to arsenic leaves of 50 μg L-1 or more. As there are many untested new wells, it is not precisely known how many people are exposed to what level. Scientific knowledge about occurrences, distribution and release mechanisms have enhanced significantly. Although deep tube wells have emerged as the most effective mitigation measure over most of the country, still there are areas where this does not work. Recent studies reported effectiveness of alternative options like intermediate deep wells and subsurface arsenic removal. There has been a major paradigm shift in the policy arena regarding arsenic mitigation.

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