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  • 1.
    Abbasi, Saeed
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements.
    A comparison between particle characteristics between two railway brake pads2013Report (Other academic)
  • 2.
    Abbasi, Saeed
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements.
    A study of nanostructured particles in railway tunnels2013Report (Other academic)
  • 3.
    Abbasi, Saeed
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements.
    Nanostructured particles in/outside compartment of running train, an on board measurement2013Report (Other academic)
  • 4.
    Abbasi, Saeed
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements.
    Non-exhaust Nano particle emission in Rail traffic2010Conference paper (Refereed)
  • 5.
    Abbasi, Saeed
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements.
    Jansson, Anders
    Stockholm University, Applied Environmental Science, Stockholm, Sweden.
    Olander, Lars
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Services Engineering.
    Olofsson, Ulf
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements.
    Sellgren, Ulf
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements.
    A pin-on-disc study of the rate of airborne wear particle emissions from railway braking materials2012In: Wear, ISSN 0043-1648, E-ISSN 1873-2577, Vol. 284, 18-29 p.Article in journal (Refereed)
    Abstract [en]

    The current study investigates the characteristics of particles generated from the wear of braking materials, and provides an applicable index for measuring and comparing wear particle emissions. A pin-on-disc tribometer equipped with particle measurement instruments was used. The number concentration, size, morphology, and mass concentration of generated particles were investigated and reported for particles 10 nm-32 mu m in diameter. The particles were also collected on filters and investigated using EDS and SEM. The effects of wear mechanisms on particle morphology and changes in particle concentration are discussed. A new index, the airborne wear particle emission rate (AWPER), is suggested that could be used in legislation to control non-exhaust emissions from transport modes, particularly rail transport.

  • 6.
    Abbasi, Saeed
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements.
    Jansson, Anders
    Sellgren, Ulf
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements.
    Olofsson, Ulf
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements.
    Particle emissions from rail traffic: a literature review2013In: Critical reviews in environmental science and technology, ISSN 1064-3389, E-ISSN 1547-6537, Vol. 43, no 23, 2211-2244 p.Article, review/survey (Refereed)
    Abstract [en]

    Particle emissions are a drawback of rail transport. This work is a comprehensive presentation of recent research into particle emissions from rail vehicles. Both exhaust and non-exhaust particle emissions are considered when examining particle characteristics such as  PM10, and PM2.5 concentration levels, size, morphology, composition, as well as adverse health effects, current legislation, and available and proposed solutions for reducing such emissions. High concentration levels in enclosed rail traffic environments are reported and some toxic effects of the particles. We find that only a few limited studies have examined the adverse health effects of non-exhaust particle emissions and that no relevant legislation exists. Thus further research in this area is warranted.

  • 7.
    Abbasi, Saeed
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements.
    Olander, Lars
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Services Engineering.
    Larsson, Christina
    Bombardier Transportation Sweden AB, Västerås, Sweden.
    Jansson, Anders
    Stockholm University, Applied Environmental Science, Stockholm, Sweden.
    Olofsson, Ulf
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Tribologi.
    Sellgren, Ulf
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements.
    A field test study of airborne wear particles from a running regional train2012In: IMechE, Part F: Journal of Rail and Rapid Transit, ISSN 0954-4097, Vol. 226, no 1, 95-109 p.Article in journal (Refereed)
    Abstract [en]

    Inhalable airborne particles have inverse health affect. In railways, mechanical brakes, the wheel–rail contact, current collectors, ballast, sleepers, and masonry structures yield particulate matter. Field tests examined a Swedish track using a train instrumented with particle measurement devices, brake pad temperature sensors, and speed and brake sensors. The main objective of this field test was to study the characteristics of particles generated from disc brakes on a running train with an on-board measuring set-up.

    Two airborne particle sampling points were designated, one near a pad–rotor disc brake contact and a second under the frame, not near a mechanical brake or the wheel–rail contact; the numbers and size distributions of the particles detected were registered and evaluated under various conditions (e.g. activating/deactivating electrical brakes or negotiating curves). During braking, three speed/temperature-dependent particle peaks were identified in the fine region, representing particles 280 nm, 350 nm, and 600 nm in diameter. In the coarse region, a peak was discerned for particles 3–6 μm in diameter. Effects of brake pad temperature on particle size distribution were also investigated. Results indicate that the 280 nm peak increased with increasing temperature, and that electrical braking significantly reduced airborne particle numbers. FESEM images captured particles sizing down to 50 nm. The ICP-MS results indicated that Fe, Cu, Zn, Al, Ca, and Mg were the main elements constituting the particles.

     

  • 8.
    Abbasi, Saeed
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements.
    Olofsson, Ulf
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements.
    Sellgren, Ulf
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements.
    A study of friction modifiers on airborne wear particles from wheel-rail contact2012Conference paper (Refereed)
    Abstract [en]

    Wheel-rail contact and its wear process are crucial issues in maintenance and operating of rolling stocks. During wheel-rail contact, materials in mating faces are worn off and some of them transferred to airborne particles. Eventhough the wear process in wheel-rail contact are well-known, few studies have been conducted on the airborne particles from wheel-rail contact.

    The purpose of this study is to investigate the effect of using different friction modifier on the amount of airbotne particles from wheel-rail contact in a laboratory simulation. In this regard, a series laboratory tests were used by using round head pin (R=25mm) and dead weight 40 N in a pin-on-disc machine. This set-up simulates a contact pressure around 750 MPa on the pin head.

    The amount of airborne particles and their characteristics were investigated in dry-contact, and non-dry contacts whereas a lubricant, Binol rail 510 and a friction modifier, tramsilence were used. According to the results, the effects of using Binol rail to reduce the amount of airborne particles were considerable.

  • 9.
    Abbasi, Saeed
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements.
    Olofsson, Ulf
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements.
    Sellgren, Ulf
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements.
    Airborne wear particles from train traffic2010Conference paper (Refereed)
  • 10.
    Abbasi, Saeed
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements.
    Olofsson, Ulf
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements.
    Sellgren, Ulf
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements.
    Experiences of measuring airborne wear particles from braking materials and wheel-rail contact2012Conference paper (Refereed)
    Abstract [en]

    During braking both of the discs and pads of disc brakes are worn. Since disc brakes are not sealed, some of the generated wear particles can become airborne.  Wheel-rail is also subjected to wear process during braking as well as normal running. They also contribute to generate airborne particles. Several studies have found an association between adverse health effects and the concentration of particles in the atmosphere, so it is of interest to improve our knowledge of the airborne wear particles generated by disc brakes.

    The present work includes results from full scale testing of rail vehicles. Particle size distribution, morphology and elemental contents are presented and discussed for different combinations of disc and pad materials. Due to high back ground concentration levels in field tests, dedicated laboratory test set ups on a reduced scale were designed and utilized for airborne particle studies with zero background level.

    Promising correlation between field test and the lab set up is identified. Different ways of using this test set up for evaluating how the composition of the airborne particles is classified with respect to their health effects are discussed. Furthermore, different ways of using the proposed method to rank and to quantify airborne particle emission factors are presented.

  • 11.
    Abbasi, Saeed
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements.
    Olofsson, Ulf
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements.
    Sellgren, Ulf
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements.
    Lack of applicable criteria in non-exhaust emission legislation: AWPER index a practical solution2011Conference paper (Refereed)
  • 12.
    Abbasi, Saeed
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements.
    Olofsson, Ulf
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements.
    Sellgren, Ulf
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements.
    Olander, Lars
    A field investigation of the size and morphology and chemical composition of airborne particles in rail transport2010Conference paper (Refereed)
  • 13.
    Abbasi, Saeed
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements.
    Olofsson, Ulf
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements.
    Sellgren, Ulf
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements.
    Olander, Lars
    Larsson, christina
    A field investigation of the size, morphology and chemical composition of airborne particles in rail transport2010Conference paper (Refereed)
    Abstract [en]

    The health effects of inhalable airborne particles are well documented. In the European Union the European Council mandates that the level of airborne particles with a diameter smaller than 10 µm (PM10) must not exceed an annual average of 40 µg/m3. Examples of possible sources from rail transport are mechanical brakes, wheel rail contact, current collectors, ballast, sleepers and masonry structures. In this regard, a series of field tests have been conducted on a regular Swedish track using a regional train instrumented with: particle measurement devices, temperature sensors in brake pads and sensors to measure the magnitude of train speed and a GPS.

    Two sampling points for airborne particles were designated in the train under frame. One of the sampling points was near a pad to rotor disc brake contact and a second global sampling point was chosen under the frame, but not near a mechanical brake or the wheel-rail contact. The first one was highly influenced by brake pad wear debris and the other one was influenced by all of the brake pads, wheel and rail wear debris as well as re-suspension. In each sampling points, three tubes were linked to three particle measurement devices. Two sets of Ptrak, Dustrak and Grimm devices were used. The Ptrak 8525 was an optical particle measurement device which could measure particle diameter in the size interval of 20 nm up to 1 micrometer. The Dustrak was used to measure particle mass concentration. The Grimm 1.109 was an aerosol spectrometer which counted number of particles from 0.25 micrometer to 32 micrometer in 31 intervals. These two Grimm devices were equipped with Millipore filters in the devices outlets to capture particles for further studies on morphology and matter of particles.

    The total number and size distribution of the particles for these two sampling points were registered and evaluated in different situations such as activating and deactivating electrical brake or train curve negotiating.

    During braking, three peaks of 250 nm, 350 nm and 600 nm in diameter, with the 350 nm peak dominating were identified in the fine particle region. In the coarse particle region, a peak of around 3-6 µm in diameter was discovered. The brake pad temperature effects on particle size distribution were also investigated and the results showed that the peak around 250 nm increased. Furthermore, the activation of electrical braking significantly reduced the number of airborne particles.

    A SEM was used to capture the images from collected particles on filters. Furthermore, an ICP-Ms method was used to investigate the elemental contents of the particulates on the filter.  In this case the main contribution belonged to Fe, Si, Al, Ca, Cu, Zn. The higher amount of some elements weights such as calcium, silicon, sodium and aluminum in the global sampling point filters revealed that ballast and concrete sleepers were the main sources for these particles although some of them originated from rail, wheel, brake disc and brake pad as well.

  • 14.
    Abbasi, Saeed
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements.
    Olofsson, Ulf
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements.
    Tritscher, Trosten
    TSI.
    Krinke, Thomas
    TSI.
    On-board study of nano- and micrometer-particle characteristics of a running electric train2013Conference paper (Refereed)
  • 15.
    Abbasi, Saeed
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements.
    Olofsson, Ulf
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements.
    Zhu, Yi
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements.
    Sellgren, Ulf
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements.
    Pin-on-disc study of the effects of railway friction modifiers on airborne wear particles from wheel-rail contact2013In: Tribology International, ISSN 0301-679X, E-ISSN 1879-2464, Vol. 60, 136-139 p.Article in journal (Refereed)
    Abstract [en]

    Knowledge of wheel–rail interaction is crucial to wheel and rail maintenance. In this interaction, some of theworn-off material is transformed into airborne particles. Although such wear is well understood, few studiestreat the particles generated. We investigated friction modifiers' effects on airborne particles characteristicsgenerated in wheel-rail contacts in laboratory conditions. Pin-on-disc machine testing with a round-head pinloaded by a dead weight load 40 N simulated maximum contact pressure over 550 MPa. Airborne particlecharacteristics were investigated in dry contacts and in ones lubricated with biodegradable rail grease andwater- and oil-based friction modifiers. The number of particles declined with the grease; the number ofultrafine particles increased with the water-based friction modifier, mainly due to water vaporization.

  • 16.
    Abbasi, Saeed
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements.
    Sellgren, Ulf
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements.
    Olofsson, Ulf
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements.
    Particle emission from rail vehicles: A literature review2012In: Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit, Sage Publications, 2012Conference paper (Refereed)
    Abstract [en]

    Emission of airborne particles is a side effect from rail transport. This work reviews recent research on particle emissions from rail vehicles. Both exhaust and non-exhaust particle emissions are characterized by size, morphology, composition, and size distribution. Current legislation, knowledge of adverse health effects, and available and proposed solutions for emission reductions are also treated. There has been much focus on exhaust emissions, but only a few limited studies have investigated non-exhaust particle emissions, which contain a significant amount of metallic materials. A new method for measuring the airborne wear particle emission rate (AWPER) is proposed as a first step to guide new legislations and to focus further research on non-exhaust airborne emission, i.e., research on the generation mechanisms for particle emissions and their adverse health effects.

  • 17.
    Abbasi, Saeed
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements. KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Sellgren, Ulf
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements.
    Olofsson, Ulf
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements. KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Technical note: Experiences of studying airborne wear particles from road and rail transport2013In: Aerosol and Air Quality Research, ISSN 1680-8584, Vol. 13, no 4, 1161-1169 p.Article in journal (Refereed)
    Abstract [en]

    Airborne particles and their adverse effects on air quality have been recognized by humans since ancient times. Current exhaust emission legislations increase the relative contribution of wear particles on the PM levels. Consequently, wearbased particle emissions from rail and road transport have raised concerns as ground transportation is developing quickly. Although scientific research on airborne wear-based particles started in 1909, there is almost no legislation that control the generation of wear-based particles. In addition, there is no accepted and approved standard measurement technique for monitoring and recording particle characteristics. The main objective of this study is to review recent experimental work in this field and to discuss their set-ups, the sampling methods, the results, and their limitations, and to propose measures for reducing these limitations.

  • 18.
    Abbasi, Saeed
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements.
    Wahlström, Jens
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements.
    Olander, Lars
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Services Engineering.
    Larsson, Christina
    Bombardier Transportation Sweden AB, Västerås, Sweden.
    Olofsson, Ulf
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Tribologi.
    Sellgren, Ulf
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements.
    A study of airborne wear particles generated from organic railway brake pads and brake discs2011In: Wear, ISSN 0043-1648, E-ISSN 1873-2577, Vol. 273, no 1, 93-99 p.Article in journal (Refereed)
    Abstract [en]

    Brake pads on wheel-mounted disc brakes are often used in rail transport due to their good thermal properties and robustness. During braking, both the disc and the pads are worn. This wear process generates particles that may become airborne and thus affect human health. The long term purpose of ‘Airborne particles in Rail transport’ project is to gain knowledge on the wear mechanisms in order to find means of controlling the number and size distribution of airborne particles. In this regard, a series of full-scale field tests and laboratory tests with a pin-on-disc machine have been conducted. The morphology and the matter of particles, along with their size distribution and concentration, have been studied. The validity of results from the pin-on-disc simulation has been verified by the field test results. Results show an ultra-fine peak for particles with a diameter size around 100 nm in diameter, a dominant fine peak for particles with a size of around 350 nm in diameter, and a coarse peak with a size of 3-7 μm in diameter. Materials such as iron, copper, aluminium, chromium, cobalt, antimony, and zinc have been detected in the nano-sized particles.

  • 19. Abderrazek, K.
    et al.
    Uheida, Abdusalam
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Functional Materials, FNM.
    Seffen, M.
    Muhammed, Mamoun
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Functional Materials, FNM.
    Srasra, N. Frini
    Srasra, E.
    Photocatalytic degradation of indigo carmine using [Zn-Al] LDH supported on PAN nanofibres2015In: Clay minerals, ISSN 0009-8558, E-ISSN 1471-8030, Vol. 50, no 2, 185-197 p.Article in journal (Refereed)
    Abstract [en]

    Zn-Al layered double hydroxides (LDH), before and after calcination, were tested for the removal of indigo carmine (IC) dye from solution. These LDH photocatalysts were characterized by powder x-ray diffraction (PXRD), Fourier transform infrared (FTIR) spectroscopy, thermogravimetry/differential thermogravimetry (TG/DTG), nitrogen physisorption at -196 degrees C, scanning electron microscopy (SEM) and diffuse reflectance spectrophotometry (DRS). The different photocatalysts were supported on polyacrylonitrile (PAN) nanofibres, so that filtration was unnecessary. The PXRD and FTIR analyses showed that the IC adsorption on c-Zn-Al-3-500 (LDH calcined at 500 degrees C) was enhanced by construction of the hydrotalcite matrix intercalated with the dye. The intercalation was clearly evidenced by the appearance of a peak at low degrees 2 theta values. All of the materials prepared exhibited photocatalytic activity, which for the c-Zn-Al-3-500 was comparable to that of commercial PAN-supported ZnO nanoparticles (100% degradation after 180 min). Kinetic studies showed that the degradation of the IC followed a pseudo-first order rate. The high activity and the ease of both synthesis and separation processes rendered this photocatalyst a promising candidate for environmental remediation.

  • 20.
    Abrehdary, Majid
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geodesy and Satellite Positioning. Univ Karlstad, Sweden.
    Sjöberg, L. E.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geodesy and Satellite Positioning.
    Bagherbandi, Mohammad
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geodesy and Satellite Positioning. Univ Gavle, Sweden.
    Sampietro, D.
    Towards the Moho depth and Moho density contrast along with their uncertainties from seismic and satellite gravity observations2017In: Journal of Applied Geodesy, ISSN 1862-9016, E-ISSN 1862-9024, Vol. 11, no 4, 231-247 p.Article in journal (Refereed)
    Abstract [en]

    We present a combined method for estimating a new global Moho model named KTH15C, containing Moho depth and Moho density contrast (or shortly Moho parameters), from a combination of global models of gravity (GOCO05S), topography (DTM2006) and seismic information (CRUST1.0 and MDN07) to a resolution of 1 degrees x 1 degrees based on a solution of Vening Meinesz-Moritz' inverse problem of isostasy. This paper also aims modelling of the observation standard errors propagated from the Vening Meinesz-Moritz and CRUST1.0 models in estimating the uncertainty of the final Moho model. The numerical results yield Moho depths ranging from 6.5 to 70.3 km, and the estimated Moho density contrasts ranging from 21 to 650 kg/m(3), respectively. Moreover, test computations display that in most areas estimated uncertainties in the parameters are less than 3 km and 50 kg/m(3), respectively, but they reach to more significant values under Gulf of Mexico, Chile, Eastern Mediterranean, Timor sea and parts of polar regions. Comparing the Moho depths estimated by KTH15C and those derived by KTH11C, GEMMA2012C, CRUST1.0, KTH14C, CRUST14 and GEMMA1.0 models shows that KTH15C agree fairly well with CRUST1.0 but rather poor with other models. The Moho density contrasts estimated by KTH15C and those of the KTH11C, KTH14C and VMM model agree to 112, 31 and 61 kg/m(3) in RMS. The regional numerical studies show that the RMS differences between KTH15C and Moho depths from seismic information yields fits of 2 to 4 km in South and North America, Africa, Europe, Asia, Australia and Antarctica, respectively.

  • 21. Abubakar, Abdulkareem
    et al.
    Al-Wahaibi, Yahya
    Al-Wahaibi, Talal
    Al-Hashmi, Abdul-Aziz R.
    Al-Ajmi, Adel M.
    KTH.
    Eshrati, Mohammad
    Effect of Water-Soluble Drag-Reducing Polymer on Flow Patterns and Pressure Gradients of Oil/Water Flow in Horizontal and Upward-Inclined Pipes2017In: SPE Journal, ISSN 1086-055X, E-ISSN 1930-0220, Vol. 22, no 1, 339-352 p.Article in journal (Refereed)
    Abstract [en]

    Experimental investigations of flow patterns and pressure gradients of oil/water flow with and without drag-reducing polymer (DRP) were carried out in horizontal and upward-inclined acrylic pipe of 30.6-mm inner diameter (ID). The oil/water flow conditions of 0.1- to 1.6-m/s mixture velocities and 0.05-0.9 input oil volume fractions were used, and 2,000 ppm master solution of the water-soluble DRP was prepared and injected at controlled flow rates to provide 40 ppm of the DRP in the water phase at the test section. The flow patterns at the water-continuous flows were affected by the DRP, whereas there were no tangible effects of the DRP at the oil-continuous flow regions. The upward inclinations shifted the boundaries between stratified flows and dual continuous flows, and the boundaries between dual continuous flows and water-continuous flows to lower mixture velocities. This means that the inclinations increased the rate of dispersions. The frictional pressure gradients for both with and without DRP slightly decreased with inclinations especially at low mixture velocities, whereas the significant increases in the total pressure gradients with the inclinations were more pronounced at low mixture velocities. The inclinations did not have a major effect on the drag reductions by the DRP at the high mixture velocities and low input oil-volume fractions where the highest drag reductions recorded were 64% at 0 degrees inclination and 62% at both + 5 degrees and +10 degrees inclinations.  However, the inclinations increased the drag reductions as the input oil-volume fractions were increased before phase-inversion points.

  • 22.
    Ackermann, Thomas
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Historical Development and Current Status of Wind Power2005In: Wind Power in Power Systems, John Wiley & Sons, 2005, 1, 5-24 p.Chapter in book (Other academic)
  • 23.
    Ackermann, Thomas
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Historical Development and Current Status of Wind Power2012In: Wind Power in Power Systems, Second Edition, John Wiley & Sons, 2012, 21-24 p.Chapter in book (Refereed)
    Abstract [en]

    The chapter provides an overview of the historical development (mechanical and electrical power generation) of wind power. It also present the current status of wind power world-wide (capacity installed) together with a discussion of the main drivers for the wind power development, e.g. feed-in tariffs, green certificates etc. Furthermore, the chapter briefly discuss the current trends in wind turbine technology, e.g. larger turbines, and projects development, e.g. offshore wind power.

  • 24.
    Ackermann, Thomas
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Transmission Systems for Offshore Wind Farms2005In: Wind Power in Power Systems, John Wiley & Sons, 2005, 479-503 p.Chapter in book (Other academic)
  • 25.
    Ackermann, Thomas
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Wind Power in Power Systems2005Book (Other academic)
    Abstract [en]

    As environmental concerns have focussed attention on the generation of electricity from clean and renewable sources, wind energy has become the world's fastest growing energy source. The authors draw on substantial practical experience to address the technical, economic and safety issues inherent in the exploitation of wind power in a competitive electricity market. Presenting the reader with all the relevant background information key to understanding the integration of wind power into the power systems, this leading edge text: Presents an international perspective on integrating a high penetration of wind power into the power system Offers broad coverage ranging from basic network interconnection issues to industry deregulation and future concepts for wind turbines and power systems Discusses wind turbine technology, industry standards and regulations along with power quality issues Considers future concepts to increase the penetration of wind power in power systems Presents models for simulating wind turbines in power systems Outlines current research activities Essential reading for power engineers, wind turbine designers, wind project development and wind energy consultants dealing with the integration of wind power systems into distribution and transmission networks, this text would also be of interest to network engineers working for power utility companies dealing with interconnection issues and graduate students and researchers in the field of wind power and power systems.

  • 26.
    Ackermann, Thomas
    KTH.
    Wind Power in Power Systems, Second Edition2012Collection (editor) (Refereed)
    Abstract [en]

    The second edition of the highly acclaimed Wind Power in Power Systems has been thoroughly revised and expanded to reflect the latest challenges associated with increasing wind power penetration levels. Since its first release, practical experiences with high wind power penetration levels have significantly increased. This book presents an overview of the lessons learned in integrating wind power into power systems and provides an outlook of the relevant issues and solutions to allow even higher wind power penetration levels. This includes the development of standard wind turbine simulation models. This extensive update has 23 brand new chapters in cutting-edge areas including offshore wind farms and storage options, performance validation and certification for grid codes, and the provision of reactive power and voltage control from wind power plants. Key features: Offers an international perspective on integrating a high penetration of wind power into the power system, from basic network interconnection to industry deregulation; Outlines the methodology and results of European and North American large-scale grid integration studies; Extensive practical experience from wind power and power system experts and transmission systems operators in Germany, Denmark, Spain, UK, Ireland, USA, China and New Zealand; Presents various wind turbine designs from the electrical perspective and models for their simulation, and discusses industry standards and world-wide grid codes, along with power quality issues; Considers concepts to increase penetration of wind power in power systems, from wind turbine, power plant and power system redesign to smart grid and storage solutions. Carefully edited for a highly coherent structure, this work remains an essential reference for power system engineers, transmission and distribution network operator and planner, wind turbine designers, wind project developers and wind energy consultants dealing with the integration of wind power into the distribution or transmission network. Up-to-date and comprehensive, it is also useful for graduate students, researchers, regulation authorities, and policy makers who work in the area of wind power and need to understand the relevant power system integration issues.

  • 27.
    Ackermann, Thomas
    et al.
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Holttinen, H.
    Overview of Integration Studies - Methodologies and Results2012In: Wind Power in Power Systems, Second Edition, John Wiley & Sons, 2012, 2, 361-386 p.Chapter in book (Refereed)
  • 28.
    Ackermann, Thomas
    et al.
    KTH, School of Electrical Engineering (EES), Electric Power Systems. Energynautics GmbH, Germany; Technical University in Darmstadt (TUD), Germany.
    Morthorst, P. E.
    Economic Aspects of Wind Power in Power Systems2005In: Wind Power in Power Systems, John Wiley & Sons, 2005, 383-410 p.Chapter in book (Other academic)
  • 29.
    Ackermann, Thomas
    et al.
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Orths, A.
    Rudion, K.
    Transmission Systems for Offshore Wind Power Plants and Operation Planning Strategies for Offshore Power Systems2012In: Wind Power in Power Systems, John Wiley & Sons, 2012, 2, 293-327 p.Chapter in book (Refereed)
    Abstract [en]

    The electric system within an offshore wind power plant and its connection to the main power system pose new challenges to the experts. The best way of interconnecting the wind turbines inside a wind farm has to be found, fulfilling both, redundancy requirements without compromising economic feasibility. The best choice between technologies (HVAC, HVDC - VSC or LCC) for connecting windfarms to shore has to be made, depending on several criteria. The risk of losing this connection versus redundancy has to be economically evaluated. By combining interconnectors and offshore windfarm connections in a modular way, a DC offshore grid can be developed. Anyhow, already during the planning phase the secure operation should be considered thoroughly, because the optimal architecture has to be found, minimizing the necessary assets ensuring secure operation and facilitating later expansion options. The interaction with the onshore grid has to be investigated as well. To enable investigations covering these issues a benchmark offshore test system has been developed which is described in this chapter.

  • 30.
    Ackermann, Thomas
    et al.
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Söder, Lennart
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    The Value of Wind Power2012In: Wind Power in Power Systems, John Wiley & Sons, 2012, 2, 131-155 p.Chapter in book (Refereed)
    Abstract [en]

    The aim of the power plants in a power system is to supply the load in an economical, reliable and environmentally acceptable way. Different power plants can fulfil these requirements in different ways. In order to select the right sources it is important to compare the value of the different sources using an objective approach. The aim of this chapter is describe the different needs of a power system and how these needs can be met with wind power, that is, the value of wind power in a certain system. The values are operating cost value, capacity value, control value, grid loss reduction value and grid investment value. The values can be calculated for different types of power plants, they can be both positive and negative, and they can be calculated both as a physical cost value and a market value.

  • 31.
    Ackermann, Thomas
    et al.
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Tröster, E.
    New Control Concept for Offshore Wind Power Plants: Constant-Speed Turbines on a Grid with Variable Frequency2012In: Wind Power in Power Systems, John Wiley & Sons, 2012, 2, 345-359 p.Chapter in book (Refereed)
    Abstract [en]

    By using a permanent magnet induction machine as wind generator, the gearbox and converter can be omitted, and the total number of parts reduced leading to a low maintenance and reliable turbine for offshore application. The rotation speed of the turbine however cannot be matched to the wind speed, reducing the energy yield at part load. To overcome this drawback, a central converter can be used, which adjusts the frequency of the local grid in the wind park; this is the so-called park-variable concept. This concept has been compared with respect to energy yield with constant speed and variable speed turbines. Overall, the differences in energy yield of the investigated concepts are so small that other criteria, such as reliability or cost, may be relevant for the selection of one or the other approach. Above all, the park-variable concept represents an interesting alternative to today's common concepts.

  • 32.
    Acuña, José
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Distributed thermal response tests: New insights on U-pipe and Coaxial heat exchangers in groundwater-filled boreholes2013Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    U-pipe Borehole Heat Exchangers (BHE) are widely used today in ground source heating and cooling systems in spite of their less than optimal performance. This thesis provides a better understanding on the function of U-pipe BHEs and Investigates alternative methods to reduce the temperature difference between the circulating fluid and the borehole wall, including one thermosyphon and three different types of coaxial BHEs.

    Field tests are performed using distributed temperature measurements along U-pipe and coaxial heat exchangers installed in groundwater filled boreholes. The measurements are carried out during heat injection thermal response tests and during short heat extraction periods using heat pumps. Temperatures are measured inside the secondary fluid path, in the groundwater, and at the borehole wall. These type of temperature measurements were until now missing.

    A new method for testing borehole heat exchangers, Distributed Thermal Response Test (DTRT), has been proposed and demonstrated in U-pipe, pipe-in-pipe, and multi-pipe BHE designs. The method allows the quantification of the BHE performance at a local level.

    The operation of a U-pipe thermosyphon BHE consisting of an insulated down-comer and a larger riser pipe using CO2 as a secondary fluid has been demonstrated in a groundwater filled borehole, 70 m deep. It was found that the CO2 may be sub-cooled at the bottom and that it flows upwards through the riser in liquid state until about 30 m depth, where it starts to evaporate.

    Various power levels and different volumetric flow rates have been imposed to the tested BHEs and used to calculate local ground thermal conductivities and thermal resistances. The local ground thermal conductivities, preferably evaluated at thermal recovery conditions during DTRTs, were found to vary with depth. Local and effective borehole thermal resistances in most heat exchangers have been calculated, and their differences have been discussed in an effort to suggest better methods for interpretation of data from field tests.

    Large thermal shunt flow between down- and up-going flow channels was identified in all heat exchanger types, particularly at low volumetric flow rates, except in a multi-pipe BHE having an insulated central pipe where the thermal contact between down- and up-coming fluid was almost eliminated.

    At relatively high volumetric flow rates, U-pipe BHEs show a nearly even distribution of the heat transfer between the ground and the secondary fluid along the depth. The same applies to all coaxial BHEs as long as the flow travels downwards through the central pipe. In the opposite flow direction, an uneven power distribution was measured in multi-chamber and multi-pipe BHEs.

    Pipe-in-pipe and multi-pipe coaxial heat exchangers show significantly lower local borehole resistances than U-pipes, ranging in average between 0.015 and 0.040 Km/W. These heat exchangers can significantly decrease the temperature difference between the secondary fluid and the ground and may allow the use of plain water as secondary fluid, an alternative to typical antifreeze aqueous solutions. The latter was demonstrated in a pipe-in-pipe BHE having an effective resistance of about 0.030 Km/W.

    Forced convection in the groundwater achieved by injecting nitrogen bubbles was found to reduce the local thermal resistance in U-pipe BHEs by about 30% during heat injection conditions. The temperatures inside the groundwater are homogenized while injecting the N2, and no radial temperature gradients are then identified. The fluid to groundwater thermal resistance during forced convection was measured to be 0.036 Km/W. This resistance varied between this value and 0.072 Km/W during natural convection conditions in the groundwater, being highest during heat pump operation at temperatures close to the water density maximum.

  • 33.
    Acuña, José
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Improvements of U-pipe Borehole Heat Exchangers2010Licentiate thesis, monograph (Other academic)
    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.

  • 34.
    Acuña, José
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Palm, Björn
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Distributed thermal response tests on pipe-in-pipe borehole heat exchangers2013In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 109, no SI, 312-320 p.Article in journal (Refereed)
    Abstract [en]

    Borehole Thermal Energy Storage systems typically use U-pipe Borehole Heat Exchangers (BHE) having borehole thermal resistances of at least 0.06 K m/W. Obviously, there is room for improvement in the U-pipe design to decrease these values. Additionally, there is a need for methods of getting more detailed knowledge about the performance of BHEs. Performing Distributed Thermal Response Tests (DTRT) on new proposed designs helps to fill this gap, as the ground thermal conductivity and thermal resistances in a BHE can be determined at many instances in the borehole thanks to distributed temperature measurements along the depth. In this paper, results from three heat injection DTRTs carried out on two coaxial pipe-in-pipe BHEs at different flow rates are presented for the first time. The tested pipe-in-pipe geometry consists of a central tube inserted into a larger external flexible pipe, forming an annular space between them. The external pipe is pressed to the borehole wall by applying a slight overpressure at the inside, resulting in good thermal contact and at the same time opening up for a novel method for measuring the borehole wall temperature in situ, by squeezing a fiber optic cable between the external pipe and the borehole wall. A reflection about how to calculate borehole thermal resistance in pipe-in-pipe BHEs is presented. Detailed fluid and borehole wall temperatures along the depth during the whole duration of the DTRTs allowed to calculate local and effective borehole thermal resistances and ground thermal conductivities. Local thermal resistances were found to be almost negligible as compared to U-pipe BHEs, and the effective borehole resistance equal to about 0.03 K m/W. The injected power was found to be almost evenly distributed along the depth.

  • 35.
    Adjei-Darko, Priscilla
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Remote Sensing and Geographic Information Systems for Flood Risk Mapping and Near Real-time Flooding Extent Assessment in the Greater Accra Metropolitan Area2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Disasters, whether natural or man-made have become an issue of mounting concern all over the world. Natural disasters such as floods, earthquakes, landslides, cyclones, tsunamis and volcanic eruptions are yearly phenomena that have devastating effect on infrastructure and property and in most cases, results in the loss of human life. Floods are amongst the most prevalent natural disasters. The frequency with which floods occur, their magnitude, extent and the cost of damage are escalating all around the globe. Accra, the capital city of Ghana experiences the occurrence of flooding events annually with dire consequences. Past studies demonstrated that remote sensing and geographic information system (GIS) are very useful and effective tools in flood risk assessment and management.  This thesis research seeks to demarcate flood risk areas and create a flood risk map for the Greater Accra Metropolitan Area using remote sensing and Geographic information system. Multi Criteria Analysis (MCA) is used to carry out the flood risk assessment and Sentinel-1A SAR images are used to map flood extend and to ascertain whether the resulting map from the MCA process is a close representation of the flood prone areas in the study area.  The results show that the multi-criteria analysis approach could effectively combine several criteria including elevation, slope, rainfall, drainage, land cover and soil geology to produce a flood risk map. The resulting map indicates that over 50 percent of the study area is likely to experience a high level of flood.  For SAR-based flood extent mapping, the results show that SAR data acquired immediately after the flooding event could better map flooding extent than the SAR data acquired 9 days after.  This highlights the importance of near real-time acquisition of SAR data for mapping flooding extent and damages.  All parts under the study area experience some level of flooding. The urban land cover experiences very high, and high levels of flooding and the MCA process produces a risk map that is a close depiction of flooding in the study area.  Real time flood disaster monitoring, early warning and rapid damage appraisal have greatly improved due to ameliorations in the remote sensing technology and the Geographic Information Systems.

  • 36.
    Admass, Muluneh
    KTH, School of Architecture and the Built Environment (ABE), Land and Water Resources Engineering.
    3-D numerical modeling of flow and sediment transport in rivers2005Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    The fully integrated 3-D, time dependant, hydrodynamic and sediment transport numerical model ECOMSED was used to simulate flow and sediment transport in rivers. ECOMSED was originally developed for large water bodies such as lakes and oceans and solves the primitive equations of RANS along with a second order turbulence model in an orthogonal curvilinear σ- coordinate system. The availability of the model as an open FORTRAN source code made modifications and addition of new models possible. A new bed load transport model was implemented in the code as well as improvements in treatment of river roughness parameterization, bed form effects, and automatic update of flow depth due to bed evolution. The model was applied to 1- km long reach of the River Klarälven, Sweden, where it bifurcates into two west and east channels. The water surface and the flow division in the channels were made in agreement with field data by spatially varying the roughness. However, the spatial distribution of the bed shear stress was not realistic. Improvements were made in the bottom boundary condition to represent the variable effects of bed forms on roughness depending on the flow regime and the flow depth. The improved model realistically reproduced the flow field as well as the sediment transport processes in the river Klarälven.

  • 37.
    Aga, Aboma Emiru
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Fuel Supply Investigation for an Externally Fired Microturbine based Micro CHP System: Case study on a selected site in Bishoftu, Ethiopia2013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Sudden change on earth’s climate, which is a result of an increase in CO2 in the atmosphere, is mainlycaused by burning of fossil fuels for various energy services. However, for the energy services to befavourable to the environment, there should be a balance with the environmental protection, and we cancall that “Sustainable Innovative Development”.

    “EXPLORE Polygeneration” initiative will serve as an important tool to promote the application ofrenewable technologies extending to the future sustainable energy engineering field. This paper is intendedin investigating a suitable fuel supply for the microturbine based micro CHP system available at theDivision of Heat and Power Technology, KTH, Sweden; for a site called “Alema Farm PLC”, Bishoftu,Ethiopia.

    Though there is a large biomass energy resource and a huge potential to produce hydroelectric power inEthiopia, the modern energy sector is very small and the energy system is mainly characterized by biomassfuel supplies and household energy consumption. The nation’s limited biomass energy resource is believedto have been depleting at an increasingly faster rate.

    Of the many and surplus amount of renewable energy resources available in and around Alema FarmPLC, poultry litter and pig’s manure are selected to be the two main energy sources for the CHP systemavailable in the lab, after passing through different conversion techniques. However, after consideringsome basic properties like: Energy content and Bulk Density of the fuel, Moisture content , Ashcharacteristic, Tar content, Fuel logistics, Local storage, Fuel feeder system, and Magnitude of GHGReduction; poultry litter is found to be the most convenient to produce a syngas with a Downdraftatmospheric gasifier available in the HPT lab.

    Finally, For the problems caused by the nature of the poultry litter by itself and the methods used in theconversion process, the 40 TRIZ principles of TRIZ inventive principles is used and some major pointsare recommended.

  • 38.
    Ahl, Amanda
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Eklund, Johanna
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Lundqvist, Per
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Yarime, M.
    Balancing formal and informal success factors perceived by supply chain stakeholders: A study of woody biomass energy systems in Japan2018In: Journal of Cleaner Production, ISSN 0959-6526, E-ISSN 1879-1786, Vol. 175, 50-59 p.Article in journal (Refereed)
    Abstract [en]

    Small-scale woody biomass energy systems have an inherent ability to aid in emissions reduction while stimulating local economies and, as collective energy systems, are strongly connected to supply chain design based on local conditions and stakeholder integration. Despite an abundance of forest area alongside the promotion of biomass in energy policies, however, woody biomass utilization still remains low in Japan. The woody biomass supply chain, considered as a socio-technical system, involves a complex, cross-sectoral stakeholder network in which inter-organizational dynamics necessitates well-organized management based on an understanding of formal factors such as technology, as well as informal factors such as social relations and culture. In this paper, success factor perceptions from across the woody biomass supply chain are investigated based on semi-structured interviews with four stakeholders in the Kyushu region of Japan. Identified success factors here are: 1) respect of values & traditions, 2) transportation infrastructure, 3) business model integration, 4) relationship & trust, 5) local vitalization and 6) biomass quality control. A convergence as well as divergence of perceptions are observed, involving both formal and informal dimensions. Aiming to balance perceptions and to enable long-term success of woody biomass in Japan, a series of policy implications are drawn, including cross-ministerial integration, knowledge building on wood logistics, forest certification, local coordinators, biomass quality control standards and a feed-in-tariff for heat. This paper suggests a new arena of policy-making based on the importance of considering both informal and formal dimensions in energy policy.

  • 39.
    Ahlfors, Charlotta
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Industrial Ecology.
    Bergkrantz, Malin
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Industrial Ecology.
    Energieffektivisering av en bandybana: Analys av kompressorkylteknik och fjärrvärmedriven absorptionskylteknik2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Today, the energy consumption in the world is increasing and Sweden is not an exception. Therefore, the continued work towards a sustainable development is essential in order for future generations to have the same opportunities as the people today. An important step towards this goal is to improve the energy efficiency until the next generations technology has been developed. As a result of this the energy resources of the earth could be saved which would lead to cost savings, due to the fact that operating costs would decrease with reduced energy consumption. A reduced electrical power generation would lead to reduced emissions of substances that affect the environment as well. The municipality of Västervik has worked towards a sustainable development for a long time; therefore energy efficiency in the public sector has been implemented.

    An analysis is done, based on a literature study and calculations, in purpose to decide if a change of the cooling system used for the outdoor ice rink in Gamleby would lead to reduced energy consumption and cost savings. The two different machines analysed are the existing compressor cooling machine and an alternative absorption cooling machine in combination with district heat from a local source. If excess of distinct heat could be used as heat source it would be positive for the environment and for sustainable development.

    Through calculations of the cooling demand, the sustainable economy and the CO2-emissions the following conclusions have been made. Since the coefficient of cooling performance is lower for the absorption cooling machine a switch of cooling system would result in a higher demand of energy (heat and power). Due to the different CO2-emission coefficients of the two energy sources a switch would lead to increase of CO2-emissions as well as reduce the efficiency of the resources of the earth.

    The investment cost for an absorption cooling machine is double the investment cost for a commercial compressor cooling machine. Therefore, calculations have shown that it would take 18 years until a change of the cooling system can be seen as cost-effective. This calculation is based on the most optimal conditions such as free district heating and a high value on the coefficient of performance. As well if the district heat would cost, a change would never be cost-effective. The life span of a cooling machine is approximately 25 years and due to the fact that the calculations for the optimal case are based on assumptions that are not confirmed, for instance the energy from the district heat would be free of charge, the authors of this study cannot recommend the change of cooling method for the ice rink seen through an economical perspective. To sum up, the conclusion is that a switch to absorption cooling will not result in an improvement in terms of energy efficiency, cost benefits or emission reduction. Instead, an analysis of the existing system should be made in order to identify efficiency improvement opportunities in areas such as optimization of the control system and reducing the cooling demand of the bandy ice by reducing heat transfer from the environment. 

  • 40.
    Ahlroth, Sofia
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Environmental Strategies.
    Valuation of environmental impacts and its use in environmental systems analysis tools2009Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Valuation of environmental impacts in monetary terms is a both difficult and controversial undertaking. However, the need to highlight the value of ecosystem services in policy decisions has become more and more evident in the face of climate change and diminishing biodiversity in the sea and other ecosystems. Valuing non-market goods and services, like ecosystem services, is a lively research field within environmental economics, and valuation methods have been considerably elaborated in the last ten years. In practical policy analyses, there is often a need for readily available valuations of different impacts. This thesis explores and develops several ways to include valuation of environmental impacts in different policy tools, such as cost-benefit analysis, environmental accounting and life-cycle analysis.

    The first paper in this thesis is a part of the Swedish attempts to construct and calculate an environmentally adjusted NDP (net national product). This work involved putting a price on non-marketed environmental goods and assets. The valuation methods used in paper I include many of the available methods to value non-marketed goods and services.

    Valuation of environmental impacts and/or environmental pressures is used in a number of environmental systems analysis tools besides environmental accounting. Examples are Cost-Benefit Analysis, Life Cycle Assessment, Life Cycle Cost analysis, Strategic Environmental Assessment and Environmental Management Systems. These tools have been developed in different contexts and for different purposes; the way valuation is used also differs. In paper II, the current use of values/weights in the tools is explored, as well as the usefulness of a common valuation/weighting scheme and necessary qualities of such a scheme. In the third paper, a set of generic weights meeting these criteria is developed.

    Some of the generic values in the weighting set are taken from directly from other studies, while some are calculated by applying a benefit transfer method called structural benefit transfer on results from selected valuation studies. The method is tested on a number of valuation studies in the fourth paper.

    Climate change will have a significant impact on Sweden during this century, both positive and negative. In the fifth paper, a rough estimate of the impacts on man-made capital and human health is presented. The study is an example of an impact assessment including only marketed assets valued with market prices. In the last paper, the economics of sustainable energy use is discussed; what is a sustainable energy price, and how might growth be affected if energy use is limited to a sustainable level? The discussion is based on two different models of thought: a back-casting study, describing how a sustainable future society might look like, and economic scenarios projected with general equilibrium models.

  • 41.
    Ahlroth, Sofia
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Environmental Strategies.
    Nilsson, Måns
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Environmental Strategies.
    Finnveden, Göran
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Environmental Strategies. School of Computer Science and Communication (CSC), Centres, KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Sustainable Communications, CESC.
    Hjelm, Olof
    Hochschorner, Elisabeth
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Environmental Strategies.
    Weighting and valuation in selected environmental systems analysis tools - suggestions for further developments2011In: Journal of Cleaner Production, ISSN 0959-6526, E-ISSN 1879-1786, Vol. 19, no 2-3, 145-156 p.Article in journal (Refereed)
    Abstract [en]

    In environmental systems analysis tools like Life Cycle Assessment, strategic environmental assessment, cost benefit analysis and environmental management systems, results need to be presented in a comprehensible way to make alternatives easily comparable. One way of doing this is to aggregate results to a manageable set by using weighting methods.. In this paper, we explore how weighting methods are used in some selected Environmental Systems Analysis Tools (ESATs), and suggest possible developments of their use. We examine the differences in current use patterns, discuss the reasons for and implications of such differences, and investigate whether observed differences in use are necessary. The result of our survey shows that weighting and valuation is broadly used in the examined ESATs. The use of weighting/valuation methods is different in different tools, but these differences are not always related to the application; rather, they are related to traditions and views on valuation and weighting. Also, although the requirements on the weights/values may differ between tools, there are intersections where they coincide. Monetary weights, using either endpoint or midpoint methods, are found to be useful in all the selected tools. Furthermore, the inventory shows that that there is a common need for generic sets of weights. There is a need for further research focusing on the development of consistent value sets derived with a wide range of methods. In parallel to the development of weighting methods it is important with critical evaluations of the weighting sets with regard to scientific quality, consistency and data gaps.

  • 42.
    Ahmad, Arslan
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering. Brabant Water NV, 5200 BC 's-Hertogenbosch, The Netherlands.
    Evaluation and optimization of advanced oxidation coagulation filtration (AOCF) to produce drinking water with less than 1 μg/L of arsenic2014Report (Other academic)
    Abstract [en]

    Arsenic is an extremely poisonous element. It has been reported to cause contamination of drinking water sources in many parts of the world. The current drinking water permissible limit for arsenic in the European Union is 10 μg/L. The World Health Organization has a general rule that no substance may have a higher lifetime risk of more than 1 in 100,000. However, several studies on toxicity of arsenic suggest that purely based on health effects the arsenic limit of 10 μg/L is not sufficient. The main goal of this research was to develop an efficient arsenic removal technology that could be able to produce drinking water with an arsenic concentration of less than 1 μg/L. For this purpose, an innovative three step technique, Advanced Oxidation - Coagulation - Filtration (AOCF), was investigated through bench-scale and pilot scale experiments in the Netherlands at the water treatment plant of Dorst. Firstly, prior to the investigations on AOCF, the existing arsenic removal at the water treatment plant was investigated. Secondly, through a series of bench-scale experiments, the optimum type of coagulant, its combination dose with the selected chemical oxidant and optimum process pH were determined. Eventually, the partially optimized technique from the bench-scale was implemented at the pilot scale physical model of water treatment plant Dorst where AOCF was evaluated for arsenic removal and its effect on the removal of other common undesirable groundwater constituents. The optimized AOCF technology consistently removed arsenic from groundwater to below 1 ug/L when implemented at pilot scale. The overall effluent quality also remained acceptable. The method is efficient with both types of filtration media tested in this research i.e., virgin sand and metal oxide coated sand, however virgin sand media showed slightly better arsenic removal efficiency.

  • 43.
    Ahmad, Nawaz
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Hydraulic Engineering. KTH Royal Institute of Technology.
    REACTIVE TRANSPORT MODELLING OF DISSOLVED CO2 IN POROUS MEDIA: Injection into and leakage from geological reservoirs2016Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The geological sequestration of carbon dioxide (CO2) is one of the options of controlling the greenhouse gas emissions. However, leakage of CO2 from the storage reservoir is a risk associated with geological sequestration. Over longer times, large-scale groundwater motion may cause leakage of dissolved CO2 (CO2aq).

    The objectives of this thesis are twofold. First, the modelling study analyzes the leakage of CO2aq along the conducting pathways. Second, a relatively safer mode of geological storage is investigated wherein CO2aq is injected in a carbonate reservoir. A reactive transport model is developed that accounts for the coupled hydrological transport and the geochemical reactions of CO2aq in the porous media. The study provides a quantitative assessment of the impact of advection, dispersion, diffusion, sorption, geochemical reactions, temperature, and heat transport on the fate of leaking CO2aq.

    The mass exchange between the conducting pathway and the rock matrix plays an important role in retention and reactions of leaking CO2aq. A significant retention of leaking CO2aq is caused by its mass stored in aqueous and adsorbed states and its consumption in reactions in the rock matrix along the leakage pathway. Advection causes a significant leakage of CO2aq directly from the reservoir through the matrix in comparison to the diffusion alone in the rock matrix and advection in a highly conducting, but thin fracture. Heat transport by leaking brine also plays an important role in geochemical interactions of leaking CO2aq

    Injection of CO2aq is simulated for a carbonate reservoir. Injected CO2-saturated brine being reactive causes fast dissolution of carbonate minerals in the reservoir and fast conversion of CO2aq through considered geochemical reactions. Various parameters like dispersion, sorption, temperature, and minerals reaction kinetics are found to play important role in the consumption of CO2aq in reactions.

  • 44.
    Ahmad, Nawaz
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Hydraulic Engineering. KTH Royal Institute of Technology.
    Wörman, Anders
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Hydraulic Engineering.
    Jarsjö, Jerker
    Stockholm University, Sweden.
    Sanchez-Vila, Xavier
    Universitat Politècnica de Catalunya, UPC-BarcelonaTech, 08034 Barcelona, Spain.
    Bottacin-Busolin, Andrea
    Hellevang, Helge
    Non-isothermal reactive transport modelling of dissolved CO2 leaking through a fractured caprockManuscript (preprint) (Other academic)
    Abstract [en]

    Geological storage of CO2 is considered as one of the mitigation actions for climate change adverse effects. However, some fraction of CO2 dissolved in the brine following injection, may leak from the reservoir through permeable zones such as conducting fractures. In this study we perform the reactive transport modelling of single-phase brine saturated with dissolved CO2 (CO2aq) along a conducting fracture in a clay-rich caprock. This study investigates the role of temperature and various reaction systems on the fate of migrating CO2aq, its geochemical interactions with the carbonate minerals, its conversion in geochemical reactions and associated medium porosity and permeability evolutions along the transport pathway.About 0.64% of leaking CO2aq is found converted into other ions in its geochemical interactions with calcite (simplified geochemical system). Addition of mineral dolomite in the geochemical system (extended geochemical system) results in up to 11% higher mass conversion of CO2 in reactions as compared to the simplified geochemical system. Considering extended geochemical system and heat transport by moving brine resulted in about 27.34% higher mass conversion of CO2 in reactions as compared to the simplified geochemical system. A combination of extended geochemical system, heat transport and sorption resulted in about 82.59% higher mass conversion of CO2 compared to the simplified geochemical system. Leaking CO2aq travelled less than 250 m along the fractured pathway, for a velocity of nearly 19 m/year in the fracture, due to retardation caused by mass stored in aqueous and adsorbed states.

  • 45.
    Ahmad, Nawaz
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Hydraulic Engineering. KTH Royal Institute of Technology.
    Wörman, Anders
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Hydraulic Engineering.
    Sanchez-Vila, Xavier
    Bottacin-Busolin, Andrea
    The role of advection and dispersion in the rock matrix on the transport of leaking CO2-saturated brine along a fractured zone2016In: Advances in Water Resources, ISSN 0309-1708, E-ISSN 1872-9657, Vol. 98, 132-146 p.Article in journal (Refereed)
    Abstract [en]

    CO2 that is injected into a geological storage reservoir can leak in dissolved form because of brine displacement from the reservoir, which is caused by large-scale groundwater motion. Simulations of the reactive transport of leaking CO2aq along a conducting fracture in a clay-rich caprock are conducted to analyze the effect of various physical and geochemical processes. Whilst several modeling transport studies along rock fractures have considered diffusion as the only transport process in the surrounding rock matrix (diffusive transport), this study analyzes the combined role of advection and dispersion in the rock matrix in addition to diffusion (advection-dominated transport) on the migration of CO2aq along a leakage pathway and its conversion in geochemical reactions. A sensitivity analysis is performed to quantify the effect of fluid velocity and dispersivity. Variations in the porosity and permeability of the medium are found in response to calcite dissolution and precipitation along the leakage pathway. We observe that advection and dispersion in the rock matrix play a significant role in the overall transport process. For the parameters that were used in this study, advection-dominated transport increased the leakage of CO2aq from the reservoir by nearly 305%, caused faster transport and increased the mass conversion of CO2aq in geochemical reactions along the transport pathway by approximately 12.20% compared to diffusive transport.

  • 46.
    Ahmad, Nawaz
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Hydraulic Engineering. KTH Royal Institute of Technology.
    Wörman, Anders
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Hydraulic Engineering.
    Sanchez-Vila, Xavier
    Universitat Politècnica de Catalunya, UPC-BarcelonaTech, 08034 Barcelona, Spain.
    Bottacin-Busolin, Andrea
    The role of advection and dispersion in the rock matrix on the transport of leaking CO2-saturated brine along a fractured zoneManuscript (preprint) (Other academic)
    Abstract [en]

    CO2 that is injected into a storage reservoir can leak in dissolved form because of brine displacement from the reservoir, which is caused by large-scale groundwater motion. Simulations of the reactive transport of leaking CO2aq along a conducting fracture in a clay-rich caprock are conducted to analyze the effect of various physical and geochemical processes. Whilst several modelling transport studies along rock fractures have considered diffusion as the only transport process in the surrounding rock matrix (diffusive transport), this study analyzes the combined role of advection and dispersion in the rock matrix in addition to diffusion (advection-dominated transport) on the migration of CO2aq along a leakage pathway and its conversion in geochemical reactions. A sensitivity analysis is performed to quantify the effect of fluid velocity and dispersivity. Variations in the porosity and permeability of the medium are observed in response to calcite dissolution and precipitation along the leakage pathway. We observe that advection and dispersion in the rock matrix play a significant role in the overall transport process. For the parameters that were used in this study, advection-dominated transport increased the leakage of CO2aq from the reservoir by nearly 305%, caused faster transport and increased the mass conversion of CO2aq in geochemical reactions along the transport pathway by approximately 12.20% compared to diffusive transport. 

  • 47.
    Ahmad, Nawaz
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Hydraulic Engineering. KTH Royal Institute of Technology.
    Wörman, Anders
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Hydraulic Engineering.
    Sanchez-Vila, Xavier
    Universitat Politècnica de Catalunya, UPC-BarcelonaTech, 08034 Barcelona, Spain.
    Jarsjö, Jerker
    Stockholm University, Sweden.
    Bottacin-Busolin, Andrea
    Hellevang, Helge
    Injection of CO2-saturated brine in geological reservoir: A way to enhanced storage safetyManuscript (preprint) (Other academic)
    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 is modelled. Physical and geochemical interactions of injected low-pH CO2-saturated brine with the carbonate minerals (calcite, dolomite and siderite) are investigated in the reactive transport modelling. CO2-saturated brine, being low in pH, shows high reactivity with the reservoir minerals, resulting in a significant mineral dissolution and CO2 conversion in reactions. Over the injection period of 10 years, up to 16% of the injected CO2 is 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 is found mainly in the form of ionic trapping.

  • 48.
    Ahmad, Zoe
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Industrial Ecology.
    An Assessment of the Swedish Bioeconomical Development2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Bioeconomy is an emerging term defined by the European Commission as ‘an economy based on biological,renewable resources to produce bioenergy, biobased products, services and food’. Unlike neighbouring countries Germany and Finland, Sweden lacks an official national bioeconomy strategy and the Swedish bioeconomical development is not mapped. Previous literature has not addressed the topic specifically and to do so, it was believed necessary to address relevant actors currently undergoing the bioeconomical development. It is investigated if the Swedish bioeconomical development is too slow and inefficiently regulated and if so, what measure can be taken. A literature study and 13 interviews with actors relevant to the bioeconomical transition were used to achieve the objective of the study. Concluded, the field of bioeconomy severely needs parameters to make its definition and quantification possible. Despite lacking a national bioeconomy strategy, Sweden’s bioeconomical development is not stalled. The government pursues the transition through specifically created institutions and big investments. Compared to Finland, Sweden performs well within the current bioeconomical sectors (biomass production and biobased sectors were assessed). Parameters must be established to enable a better mapping of the process and to complete the bioeconomical transition within Sweden.

  • 49.
    Ahmadi Achachlouei, Mohammad
    Lund University.
    Contextualization of Information Systems Studies for Developing Countries2010Conference paper (Other academic)
    Abstract [en]

    This thesis project seeks to reconcile perspectives in universalism and localism such that developing countries might benefit from achievements of developed countries in the field of information systems studies while considering the institutional, socio-economic, and contextual configurations particular to their own societies. This project will explore the key concepts borrowed from sociology of science and technology and illustrate their possible uses in information systems studies.

  • 50.
    Ahmadi Achachlouei, Mohammad
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Environmental Strategies. KTH, School of Computer Science and Communication (CSC), Centres, School of Architecture and the Built Environment (ABE), Centres, Centre for Sustainable Communications, CESC.
    Environmental Impacts of Electronic Media: A Comparison of a Magazine’s Tablet and Print Editions2013Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    The aim of this thesis is to assess potential environmental impacts of electronic media distribution and consumption—from a life cycle perspective—as compared to those of print media.

    The thesis consists of a cover essay and two papers appended at the end of the thesis. The cover essay summarizes the papers and puts them in context. The main objectives of the thesis are twofold: to assess potential environmental impacts of production and consumption of tablet editions of magazines from a life cycle perspective (Paper I), and to compare potential environmental impacts of a magazine’s print edition with that of its tablet edition (Paper II).

    The thesis examines the following specific research questions: (1) What are the main environmental impacts of print and tablet editions? (2) Which activities are giving rise to the main environmental impacts of the print and tablet editions? (3) What are the key factors influencing these impacts? (4) What are major data gaps and uncertainties?

    Based on the present assessment, it is clear that for the print magazine, pulp and paper production is the principal cause of most of the potential environmental impacts. For this reason, the use of recycled paper, rather than virgin fiber, in newsprint production may considerably offset environmental impacts.

    For the tablet edition, the content production dominates the potential environmental impacts when readers are few. This appears to be the case in an emerging state of the magazine, but with distribution of more media products to smaller groups of people, this may persist for “mature” products as well. As the number of tablet readers grows, more of the environmental impact of the is due to manufacturing of the device and electronic distribution. However, content production may still be a major factor, depending on the specific environmental impacts studied.

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