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  • 3201.
    Al-Ajmi, Adel M.
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Land and Water Resources Engineering (moved 20130630), Engineering Geology and Geophysics. Department of Petroleum and Chemical Engineering, Oman .
    Zimmerman, Robert W.
    KTH, School of Architecture and the Built Environment (ABE), Land and Water Resources Engineering (moved 20130630), Engineering Geology and Geophysics.
    A new 3D stability model for the design of non-vertical wellbores2006Conference paper (Refereed)
    Abstract [en]

    The Mohr-Coulomb failure criterion is known to be too conservative in estimating the critical mud pressure required to maintain wellbore stability, due to ignoring the strengthening effect of the intermediate principal stress. To eliminate this deficiency, we have developed a new analytical model to estimate the mud pressure required to avoid shear failure at the wall of non-vertical boreholes (i.e., the collapse pressure). This has been achieved by using a linear elastic and isotropic constitutive model for the stresses, and the Mogi-Coulomb criterion to predict failure. For comparison, the stability analysis has been also carried out using Mohr-Coulomb, the modified Lade criterion, and the Drucker-Prager criterion. We have found that implementing the Mogi-Coulomb law instead of Mohr-Coulomb does indeed lessen the conservative nature of the wellbore stability analysis. In general, the Mogi-Coulomb criterion gives an estimate of the collapse pressure that is similar to that given by the modified Lade criterion in polyaxial stress states, and similar to Mohr-Coulomb in triaxial stress states. By comparison, the Drucker-Prager criterion always underestimates the required mud weight. The developed 3D stability model has been applied in a field case study.

  • 3202.
    Al-Ajmi, Adel M.
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Land and Water Resources Engineering, Engineering Geology and Geophysics.
    Zimmerman, Robert W.
    KTH, School of Architecture and the Built Environment (ABE), Land and Water Resources Engineering, Engineering Geology and Geophysics.
    Stability analysis of vertical boreholes using the Mogi-Coulomb failure criterion2006In: International Journal of Rock Mechanics And Mining Sciences, ISSN 1365-1609, E-ISSN 1873-4545, Vol. 43, no 8, p. 1200-1211Article in journal (Refereed)
    Abstract [en]

    A main aspect of wellbore stability analysis is the selection of an appropriate rock failure criterion. The most commonly used criterion for brittle failure of rocks is the Mohr-Coulomb criterion. This criterion involves only the maximum and minimum principal stresses, a, and sigma(3), and therefore assumes that the intermediate stress 92 has no influence on rock strength. As the Mohr-Coulomb criterion ignores the strengthening effect of the intermediate stress, it is expected to be too conservative in estimating the critical mud weight required to maintain wellbore stability. Recently, Al-Ajmi and Zimmerman [Relationship between the parameters of the Mogi and Coulomb failure criterion. Int J Rock Mech Min Sci 2005;42(3):431-39.] developed the Mogi-Coulomb failure criterion, and showed that it is reasonably accurate in modelling polyaxial failure data from a variety of rocks. We then develop a model for the stability of vertical boreholes, using linear elasticity theory to calculate the stresses, and the fully-polyaxial Mogi-Coulomb criterion to predict failure. Our model leads to easily computed expressions for the critical mud weight required to maintain wellbore stability.

  • 3203. Al-ajmi, A.M
    et al.
    Zimmerman, Robert W
    KTH, School of Architecture and the Built Environment (ABE), Land and Water Resources Engineering.
    Relation between the Mogi and the Coulomb failure criteria2005In: International Journal of Rock Mechanics And Mining Sciences, ISSN 1365-1609, E-ISSN 1873-4545, Vol. 42, no 3, p. 431-439Article in journal (Refereed)
    Abstract [en]

    We have shown that linear Mogi criterion does a good job in representing rock failureunder polyaxial stress states. When σ2 = σ3 the linear version of Mogi's triaxial failurecriterion reduces exactly to the Coulomb criterion. Hence, the linear Mogi criterion can be thought of as a natural extension of the Coulomb criterion into three dimensions (i.e., polyaxial stress space). As Mohr's extension of the Coulomb criterion into three dimensions is often referred to as the Mohr-Coulomb criterion, we propose that the linear version of the Mogi criterion be known as the "Mogi-Coulomb" failure criterion. The classical Coulomb failure criterion can therefore be thought of as a special case, which applies only when σ2 = σ3 of the more general linear Mogi failure criterion. Furthermore, we found that the numerical values of the parameters that appear in the Mogi-Coulombcriterion can be estimated from conventional triaxial test data. Thus, this polyaxial failurecriterion can be applied even in the absence of polyaxial (true triaxial) data. This offers a great advantage, as most laboratories are equipped to conduct only traditional σ2 = σ3tests. Finally, we showed that if the linear form of the Mogi criterion is used, the parameters that appear in it can be unambiguously related to the traditional parameters appearing in the Coulomb failure law. The lack of such a relationship for the parameters appearing in the power-law Mogi criterion has been cited in [8] as a major drawback to the use of that model. 

  • 3204. Ala-Kaila, K.
    et al.
    Li, Jiebing
    KTH, Superseded Departments, Pulp and Paper Technology.
    Gellerstedt, Göran
    KTH, Superseded Departments, Pulp and Paper Technology.
    Chemical character of the response of softwood kraft pulp towards industrial two-stage oxygen-alkali delignification2004In: Paperi ja puu, ISSN 0031-1243, Vol. 86, no 5, p. 353-358Article, review/survey (Refereed)
    Abstract [fi]

    The transient behavior of residual material affecting the kappa number of softwood kraft pulp (termed residual lignin), was tested experimentally step-wise in an industrial two-stage oxygen-alkali delignification process. The behavior was characterized by leaching the pulps and dividing the residual lignin into four different fractions to represent the wash loss fraction, the easily leachable fraction, the slowly leachable fraction and the stagnant fraction of the lignin in pulp. Further characterization was made regarding the chemical character of these fractions, i.e. residual lignin, extractives, hexenuronic acid, and other chemical structures that contribute to the kappa number of the pulps. The componential delignification response in the two oxygen-alkali reactors and the effects of the leaching operation were comprehensively assessed regarding the behavior of these different pulp components. The results were compared with results obtained earlier for birch kraft pulp originating from the same industrial process and treated using identical experimental procedures. Application: This study gives a new perspective with which to evaluate apparent and actual responses in industrial oxygen-alkali delignification of kraft pulps.

  • 3205. Ala-Kaila, K.
    et al.
    Li, Jiebing
    KTH, Superseded Departments, Pulp and Paper Technology.
    Sevastyanova, O.
    Gellerstedt, Göran
    KTH, Superseded Departments, Pulp and Paper Technology.
    Apparent and actual delignification response in industrial oxygen-alkali delignification of birch kraft pulp2003In: TAPPI Journal, ISSN 0734-1415, Vol. 2, no 10, p. 23-27Article in journal (Refereed)
    Abstract [en]

    The time-dependent behavior of material that affects the kappa number of birch kraft pulp was experimentally tested in an industrial, two-stage, oxygen-alkali delignification process. The pulps were leached, and the leached material was divided into four different fractions: the wash loss fraction and the easily leachable, slowly leachable, and stagnant fractions. These fractions were further characterized according to their chemical natures, representing residual lignin, extractives, hexenuronic acids, and other chemical structures contributing to the kappa number of the pulps. The apparent and actual delignification responses in the two reactors and the effects of the leaching operation were thoroughly evaluated based on the behaviors to these different pulp components.

  • 3206.
    Ala-Laurinaho, J.
    et al.
    Aalto University, Finland.
    Chicherin, Dmitry
    Aalto University, Finland.
    Du, Zhou
    Aalto University, Finland.
    Simovski, C.
    Aalto University, Finland.
    Zvolensky, T.
    Aalto University, Finland.
    Räisänen, Antti V.
    Aalto University, Finland.
    Sterner, Mikael
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Baghchehsaraei, Zargham
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Shah, Umer
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Dudorov, Sergey
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Oberhammer, Joachim
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Boriskin, A. V.
    IETR, France.
    Le Coq, L.
    IETR, France.
    Fourn, Erwan
    IETR, France.
    Muhammad, S. A.
    IETR, France.
    Sauleau, Ronan
    IETR, France.
    Vorobyov, Alexander
    IETR, France.
    Bodereau, F.
    TRW Autocruise, France.
    El Haj Shhade, G.
    TRW Autocruise, France.
    Labia, T.
    TRW Autocruise, France.
    Mallejac, P.
    TRW Autocruise, France.
    Åberg, Jan
    MicroComp Nordic AB, Sweden.
    Gustafsson, M.
    MicroComp Nordic AB, Sweden.
    Schier, T.
    MicroComp Nordic AB, Sweden.
    TUMESA - MEMS tuneable metamaterials for smart wireless applications2012In: European Microwave Week 2012: "Space for Microwaves", EuMW 2012, Conference Proceedings - 7th European Microwave Integrated Circuits Conference, EuMIC 2012, IEEE , 2012, p. 95-98Conference paper (Refereed)
    Abstract [en]

    This paper describes the main results of the EU FP7 project TUMESA - MEMS tuneable metamaterials for smart wireless applications. In this project, we studied several reconfigurable antenna approaches that combine the new technology of MEMS with the new concept of artificial electromagnetic materials and surfaces (metamaterials and metasurfaces) for realisation of millimetre wave phase shifters and beam-steering devices. MEMS technology allows to miniaturise electronic components, reduce their cost in batch production, and effectively compete with semiconductor and ferroelectric based technologies in terms of losses at millimetre wavelengths. Novel tuneable materials and components proposed in this project perform as smart beam steering devices. Fabricated with MEMS technology in batch and on a single chip, proposed tuneable devices allow substituting of larger and more complex sub-system of, e.g., a radar sensor. This substitution provides a dramatic cost reduction on a system level.

  • 3207.
    Alallak, Ali
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology.
    Deburring of components: A survey of current and future deburring processes2010Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The machining operations that shape a metal component produce a raised edge or small pieces of material remaining attached to a work piece called burrs and sharp edges. The deburring process is intended to remove these imperfections and produce specific edge profiles.

    Burr formation during machining operations is one of the most significant problems encountered by industrial companies in component manufacturing. Remaining burrs after machining pose a severe risk for component breakdowns, if the burrs get loose. All work piece edges must therefore be completely defect-free.

    In the machining industry manual methods are commonly employed for burr removal. Fully automating deburring operations present a major challenge. Furthermore, removal of internal burrs of various sizes and shapes from parts sometimes becomes an extremely difficult task which causes high cost for labor, time losses, and health and safety risks.

    Increasingly, manufacturers are expected to deliver burr-free parts to their customer. Sandvik Coromant, Scania and Volvo Cars are three of these manufacturers, and these three companies have agreed to contribute to this thesis.

    Sandvik Coromant AB is part of the global enterprise Sandvik Group AB, and is world- leading in providing and developing cutting tools for the metal working industry. The company operates in over 60 countries worldwide and its main production plant is located in Gimo, Sweden [www.sandvik.com].

    Scania is a global automotive industry manufacturer of commercial vehicles—specifically heavy trucks and buses. It also manufactures diesel engines for motive power of heavy vehicles, marine, and general industrial applications. Scania was founded in 1891 in Södertälje, Sweden. Today, Scania has ten production facilities worldwide [www.scania.com].

    Volvo Car Corporation is an automobile manufacturer founded in 1927, in Gothenburg, Sweden. Volvo Cars has approximately 2,300 local dealers and around 100 national sales companies worldwide. Volvo Car Engine is a part of Volvo Cars. Volvo Car Engine produces engines and other components for other units, and it is headquartered in Skövde, Sweden [www.volvocars.com].

    All of the companies above have problems in burr minimizing and removing strategy in machining and deburring operations to achieve quality assurance. Therefore, to choose a deburring system, and to reveal the results of deburring operations, it is necessary to be able to inspect/measure burrs. But, unfortunately, most industrial companies today lack the specialized systems to measure the presence of burrs, which adversely affect the overall deburring process. In this thesis, different types and sizes of work pieces have been taken directly from the production to measure burrs, and conduct experiments on them.

    The thesis focuses on three areas:

    • A survey of the current deburring problems, including burr classification and measurement, current minimization strategies of burr formation, and current deburring methods.
    • Experiments on new and improved deburring methods, including deburring tools (e.g. drilling deburring tools, countersink tools, grinding tools and alumina fiber brushes), water-jet deburring (multi-nozzle rotary lance jets, pure and abrasive single rotary nozzle water jets).
    • A selection matrix as a thesis conclusion which relates these methods to criteria of deburring processes, such as process performance, industrial applications, quality assurance, safety and environment, costs, etc. This matrix can be a basis for a more detailed selection/decision matrix in the future.
  • 3208.
    Alallak, Ali
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Deburring of components: A survey of current and future deburring processes2010Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The machining operations that shape a metal component produce a raised edge or small pieces of material remaining attached to a work piece called burrs and sharp edges. The deburring process is intended to remove these imperfections and produce specific edge profiles. Burr formation during machining operations is one of the most significant problems encountered by industrial companies in component manufacturing. Remaining burrs after machining pose a severe risk for component breakdowns, if the burrs get loose. All work piece edges must therefore be completely defect-free. In the machining industry manual methods are commonly employed for burr removal. Fully automating deburring operations present a major challenge. Furthermore, removal of internal burrs of various sizes and shapes from parts sometimes becomes an extremely difficult task which causes high cost for labor, time losses, and health and safety risks. Increasingly, manufacturers are expected to deliver burr-free parts to their customer. Sandvik Coromant, Scania and Volvo Cars are three of these manufacturers, and these three companies have agreed to contribute to this thesis. Sandvik Coromant AB is part of the global enterprise Sandvik Group AB, and is world- leading in providing and developing cutting tools for the metal working industry. The company operates in over 60 countries worldwide and its main production plant is located in Gimo, Sweden [www.sandvik.com]. Scania is a global automotive industry manufacturer of commercial vehicles—specifically heavy trucks and buses. It also manufactures diesel engines for motive power of heavy vehicles, marine, and general industrial applications. Scania was founded in 1891 in Södertälje, Sweden. Today, Scania has ten production facilities worldwide [www.scania.com]. Volvo Car Corporation is an automobile manufacturer founded in 1927, in Gothenburg, Sweden. Volvo Cars has approximately 2,300 local dealers and around 100 national sales companies worldwide. Volvo Car Engine is a part of Volvo Cars. Volvo Car Engine produces engines and other components for other units, and it is headquartered in Skövde, Sweden [www.volvocars.com]. All of the companies above have problems in burr minimizing and removing strategy in machining and deburring operations to achieve quality assurance. Therefore, to choose a deburring system, and to reveal the results of deburring operations, it is necessary to be able to inspect/measure burrs. But, unfortunately, most industrial companies today lack the specialized systems to measure the presence of burrs, which adversely affect the overall deburring process. In this thesis, different types and sizes of work pieces have been taken directly from the production to measure burrs, and conduct experiments on them. The thesis focuses on three areas:

    •  A survey of the current deburring problems, including burr classification and measurement, current minimization strategies of burr formation, and current deburring methods.
    •  Experiments on new and improved deburring methods, including deburring tools (e.g. drilling deburring tools, countersink tools, grinding tools and alumina fiber brushes), water-jet deburring (multi-nozzle rotary lance jets, pure and abrasive single rotary nozzle water jets).
    •  A selection matrix as a thesis conclusion which relates these methods to criteria of deburring processes, such as process performance, industrial applications, quality assurance, safety and environment, costs, etc. This matrix can be a basis for a more detailed selection/decision matrix in the future.

  • 3209.
    Alam, Amit
    et al.
    KTH, School of Engineering Sciences (SCI), Mathematics (Dept.), Mathematical Statistics.
    Inas, Yakub
    KTH, School of Engineering Sciences (SCI), Mathematics (Dept.), Mathematical Statistics.
    Analys av reporäntans påverkan på prissättningen av bostäder: Slår reporänteförändringar lika mycket på bostäder av olika storlek?2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The aim of this study is to investigate whether changes of the repo rate has diverse effects on apartments of different sizes, targeting specific areas in Stockholm. A conclusion, that the effect of the repo rate differs for apartments of different sizes, was made based on regression analysis and hypothesis testing. The housing market is characterized by vast shifts and the repo rate has reached a historical low-point of -0.25 per cent. It is reflected upon how the central bank’s steering interest rate actually impacts the prices on the housing market and whether it has distinct effects on apartments of different sizes. Apartments sold between years 2005-2015 have been analyzed where the gravity of the repo rate has been taken into consideration and if its significance varies amongst apartments of different sizes. Important parameters concerning apartment prices have been utilized in the constructed model.

  • 3210.
    Alam, Assad
    KTH, School of Electrical Engineering (EES).
    Fuel-Efficient Distributed Control for Heavy Duty Vehicle Platooning2011Licentiate thesis, monograph (Other academic)
    Abstract [en]

    Freight transport demand has escalated and will continue to do so as economiesgrow. As the traffic intensity increases, the drivers are faced with increasinglycomplex tasks and traffic safety is a growing issue. Simultaneously, fossil fuel usageis escalating. Heavy duty vehicle (HDV) platooning is a plausible solution to theseissues. Even though there has been a need for introducing automated HDV platooningsystems for several years, they have only recently become possible to implement.Advancements in on-board and external technology have ushered in new possibilitiesto aid the driver and enhance the system performance. Each vehicle is able to serveas an information node through wireless communication; enabling a cooperativenetworked transportation system. Thereby, vehicles can semi-autonomously travel atshort intermediate spacings, effectively reducing congestion, relieving driver tension,improving fuel consumption and emissions without compromising safety.

    This thesis presents contributions to a framework for the design and implementation of HDV platooning. The focus lies mainly on establishing and validating realconstraints for fuel optimal control for platooning vehicles. Nonlinear and linearvehicle models are presented together with a system architecture, which dividesthe complex problem into manageable subsystems. The fuel reduction potentialis investigated through simulation models and experimental results derived fromstandard vehicles traveling on a Swedish highway. It is shown through analyticaland experimental results that it is favorable with respect to the fuel consumption tooperate the vehicles at a much shorter intermediate spacing than what is currentlydone in commercially available systems. The results show that a maximum fuelreduction of 4.7–7.7 % depending on the inter-vehicle time gap, at a set speedof 70 km/h, can be obtained without compromising safety. A systematic designmethodology for inter-vehicle distance control is presented based on linear quadraticregulators (LQRs). The structure of the controller feedback matrix can be tailoredto the locally available state information. The results show that a decentralizedcontroller gives good tracking performance, a robust system and lowers the controleffort downstream in the platoon. It is also shown that the design methodologyproduces a string stable system for an arbitrary number of vehicles in the platoon,if the vehicle configurations and the LQR weighting parameters are identical for theconsidered subsystems.

    With the results obtained in this thesis, it is argued that a vast fuel reductionpotential exists for HDV platooning. Present commercial systems can be enhancedsignificantly through the introduction of wireless communication and decentralizedoptimal control.

  • 3211.
    Alam, Assad
    KTH, School of Electrical Engineering (EES), Automatic Control.
    Fuel-Efficient Heavy-Duty Vehicle Platooning2014Doctoral thesis, monograph (Other academic)
    Abstract [en]

    The freight transport industry faces big challenges as the demand for transport and fuel prices are steadily increasing, whereas the environmental impact needs to be significantly reduced. Heavy-duty vehicle (HDV) platooning is a promising technology for a sustainable transportation system. By semi-autonomously governing each platooning vehicle at small inter-vehicle spacing, we can effectively reduce fuel consumption, emissions, and congestion, and relieve driver tension. Yet, it is not evident how to synthesise such a platoon control system and how constraints imposed by the road topography affect the safety or fuel-saving potential in practice.

    This thesis presents contributions to a framework for the design, implementation, and evaluation of HDV platooning. The focus lies mainly on establishing fuel-efficient platooning control and evaluating the fuel-saving potential in practice. A vehicle platoon model is developed together with a system architecture that divides the control problem into manageable subsystems. Presented results show that a significant fuel reduction potential exists for HDV platooning and it is favorable to operate the vehicles at a small inter-vehicle spacing. We address the problem of finding the minimum distance between HDVs in a platoon without compromising safety, by setting up the problem in a game theoretical framework. Thereby, we determine criteria for which collisions can be avoided in a worst-case scenario and establish the minimum safe distance to a vehicle ahead. A systematic design methodology for decentralized inter-vehicle distance control based on linear quadratic regulators is presented. It takes dynamic coupling and engine response delays into consideration, and the structure of the controller feedback matrix can be tailored to the locally available state information. The results show that a decentralized controller gives good tracking performance and attenuates disturbances downstream in the platoon for dynamic scenarios that commonly occur on highways. We also consider the problem of finding a fuel-efficient controller for HDV platooning based on road grade preview information under road and vehicle parameter uncertainties. We present two model predictive control policies and derive their fuel-saving potential. The thesis finally evaluates the fuel savings in practice. Experimental results show that a fuel reduction of 3.9–6.5 % can be obtained on average for a heterogenous platoon of HDVs on a Swedish highway. It is demonstrated how the savings depend on the vehicle position in the platoon, the behavior of the preceding vehicles, and the road topography. With the results obtained in this thesis, it is argued that a significant fuel reduction potential exists for HDV platooning.

  • 3212.
    Alam, Assad
    et al.
    KTH, School of Electrical Engineering (EES), Automatic Control.
    Asplund, Fredrik
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Mechatronics.
    Behere, Sagar
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Mechatronics.
    Björk, Mattias
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Mechatronics.
    Garcia Alonso, Liliana
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Mechatronics.
    Khaksari, Farzad
    KTH, School of Electrical Engineering (EES), Signal Processing.
    Khan, Altamash
    KTH, School of Electrical Engineering (EES), Signal Processing.
    Kjellberg, Joakim
    KTH, School of Electrical Engineering (EES), Automatic Control.
    Liang, Kuo-Yun
    KTH, School of Electrical Engineering (EES), Automatic Control.
    Lyberger, Rickard
    Scania CV AB.
    Mårtensson, Jonas
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Nilsson, John-Olof
    KTH, School of Electrical Engineering (EES), Signal Processing.
    Pettersson, Henrik
    Scania CV AB.
    Pettersson, Simon
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Mechatronics.
    Stålklinga, Elin
    KTH, School of Electrical Engineering (EES), Automatic Control.
    Sundman, Dennis
    KTH, School of Electrical Engineering (EES), Signal Processing.
    Zachariah, Dave
    KTH, School of Electrical Engineering (EES), Signal Processing.
    Cooperative driving according to Scoop2011Report (Other academic)
    Abstract [en]

    KTH Royal Institute of Technology and Scania are entering the GCDC 2011 under the name Scoop –Stockholm Cooperative Driving. This paper is an introduction to their team and to the technical approach theyare using in their prototype system for GCDC 2011.

  • 3213. Alam, Assad
    et al.
    Besselink, Bart
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Turri, Valerio
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Mårtensson, Jonas
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Johansson, Karl Henrik
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Heavy-Duty Vehicle Platooning for Sustainable Freight Transportation A COOPERATIVE METHOD TO ENHANCE SAFETY AND EFFICIENCY2015In: IEEE CONTROL SYSTEMS MAGAZINE, ISSN 1066-033X, Vol. 35, no 6, p. 34-56Article in journal (Refereed)
    Abstract [en]

    The current system of global trade is largely based on transportation and communication technology from the 20th century. Advances in technology have led to an increasingly interconnected global market and reduced the costs of moving goods, people, and technology around the world [1]. Transportation is crucial to society, and the demand for transportation is strongly linked to economic development. Specifically, road transportation is essential since about 60% of all surface freight transportation (which includes road and rail transport) is done on roads [2]. Despite the important role of road freight transportation in the economy, it is facing serious challenges, such as those posed by increasing fuel prices and the need to reduce greenhouse gas emissions. On the other hand, the integration of information and communication technologies to transportation systems-leading to intelligent transportation systems-enables the development of cooperative methods to enhance the safety and energy efficiency of transportation networks. This article focuses on one such cooperative approach, which is known as platooning. The formation of a group of heavy-duty vehicles (HDVs) at close intervehicular distances, known as a platoon (see Figure 1) increases the fuel efficiency of the group by reducing the overall air drag. The safe operation of such platoons requires the automatic control of the velocity of the platoon vehicles as well as their intervehicular distance. Existing work on platooning has focused on the design of controllers for these longitudinal dynamics, in which simple vehicle models are typically exploited and perfect environmental conditions, such as flat roads, are generally assumed. The broader perspective of how platooning can be effectively exploited in a freight transportation system has received less attention. Moreover, experimental validations of the fuel-saving potential offered by platooning have typically been performed by reproducing the perfect conditions as assumed in the design of the automatic controllers. This article focuses on these two aspects by addressing the following two objectives.

  • 3214.
    Alam, Assad
    et al.
    KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre. Scania CV AB, SE-15187 Södertälje, Sweden.
    Gattami, Ather
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Johansson, Karl H.
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Tomlin, Claire J.
    UC Berkeley.
    Guaranteeing safety for heavy duty vehicle platooning: Safe set computations and experimental evaluations2014In: Control Engineering Practice, ISSN 0967-0661, E-ISSN 1873-6939, Vol. 24, no 1, p. 33-41Article in journal (Refereed)
    Abstract [en]

    In this paper, we consider the problem of finding a safety criteria between neighboring heavy duty vehicles traveling in a platoon. We present a possible framework for analyzing safety aspects of heavy duty vehicle platooning. A nonlinear underlying dynamical model is utilized, where the states of two neighboring vehicles are conveyed through radar information and wireless communication. Numerical safe sets are derived through the framework, under a worst-case scenario, and the minimum safe spacing is studied for heterogenous platoons. Real life experimental results are presented in an attempt to validate the theoretical results in practice. The findings show that a minimum relative distance of 1.2 m at maximum legal velocity on Swedish highways can be maintained for two identical vehicles without endangering a collision. The main conclusion is that the relative distance utilized in commercial applications today can be reduced significantly with a suitable automatic control system.

  • 3215. Alam, Assad
    et al.
    Gattami, Ather
    KTH, School of Electrical Engineering (EES), Automatic Control.
    Johansson, Karl Henrik
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Suboptimal Decentralized Controller Design for Chain Structures: Applications to Vehicle Formations2011In: IEEE 50th Annual Conference on Decision and Control and European Control Conference, Orlando, December, 2011, IEEE , 2011, p. 6894-6900Conference paper (Refereed)
    Abstract [en]

    We consider suboptimal decentralized controllerdesign for subsystems with interconnected dynamics and costfunctions. A systematic design methodology is presented overthe class of linear quadratic regulators (LQR) for chain graphs.The methodology is evaluated on heavy duty vehicle platooningwith physical constraints. A simulation and frequency analysisis performed. The results show that the decentralized controllergives good tracking performance and a robust system. We alsoshow that the design methodology produces a string stablesystem for an arbitrary number of vehicles in the platoon, ifthe vehicle configurations and the LQR weighting parametersare identical for the considered subsystems.

  • 3216.
    Alam, Assad
    et al.
    KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Mårtensson, Jonas
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Johansson, Karl
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Experimental evaluation of decentralized cooperative cruise control for heavy-duty vehicle platooning2015In: Control Engineering Practice, ISSN 0967-0661, E-ISSN 1873-6939, Vol. 38, p. 11-25Article in journal (Refereed)
    Abstract [en]

    In this paper, we consider the problem of finding decentralized controllers for heavy-duty vehicle (HDV) platooning by establishing empiric results for a qualitative verification of a control design methodology. We present a linear quadratic control framework for the design of a high-level cooperative platooning controller suitable for modern HDVs. A nonlinear low-level dynamical model is utilized, where realistic response delays in certain modes of operation are considered. The controller performance is evaluated through numerical and experimental studies. It is concluded that the proposed controller behaves well in the sense that experiments show that it allows for short time headways to achieve fuel efficiency, without compromising safety. Simulation results indicate that the model mimics real life behavior. Experiment results show that the dynamic behavior of the platooning vehicles depends strongly on the gear switching logic, which is confirmed by the simulation model. Both simulation and experiment results show that the third vehicle never displays a bigger undershoot than its preceding vehicle. The spacing errors stay bounded within 6.8. m in the simulation results and 7.2. m in the experiment results for varying transient responses. Furthermore, a minimum spacing of -0.6. m and -1.9. m during braking is observed in simulations and experiments, respectively. The results indicate that HDV platooning can be conducted at close spacings with standardized sensors and control units that are already present on commercial HDVs today.

  • 3217.
    Alam, Assad
    et al.
    KTH, School of Electrical Engineering (EES), Automatic Control.
    Mårtensson, Jonas
    KTH, School of Electrical Engineering (EES), Automatic Control.
    Johansson, Karl H.
    KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre. KTH, School of Electrical Engineering (EES), Automatic Control.
    Look-Ahead Cruise Control for Heavy Duty Vehicle Platooning2013In: Proceedings of the 16th International IEEE Annual Conference onIntelligent Transportation Systems (ITSC 2013), IEEE conference proceedings, 2013, p. 928-935Conference paper (Refereed)
    Abstract [en]

    Vehicle platooning has become important for thevehicle industry. Yet conclusive results with respect to thefuel reduction possibilities of platooning remain unclear, inparticular when considering constraints imposed by the topography.The focus of this study is to establish whether itis more fuel-efficient to maintain or to split a platoon that isfacing steep uphill and downhill segments. Two commercialcontrollers, an adaptive cruise controller and a look-aheadcruise controller, are evaluated and alternative novel controlstrategies are proposed. The results show that an improvedfuel-efficiency can be obtained by maintaining the platoonthroughout a hill. Hence, a cooperative control strategy basedon preview information is presented, which initiates the changein velocity at a specific point in the road for all vehiclesrather than simultaneously changing the velocity to maintainthe spacing. A fuel reduction of up to 14% can be obtainedover a steep downhill segment and a more subtle benefit of0.7% improvement over an uphill segment with the proposedcontroller, compared to the combination of the commerciallyavailable cruise controller and adaptive cruise controller thatcould be used for platooning. The findings show that it isboth fuel-efficient and desirable in practice to consider previewinformation of the topography in the control strategy.

  • 3218.
    Alam, Assad
    et al.
    KTH, School of Electrical Engineering (EES), Automatic Control.
    Sahlholm, Per
    KTH, School of Electrical Engineering (EES), Automatic Control.
    A Method for Determining an Economical Speed for Heavy Vehicles2008In: Proceedings of the 15th World Congress on Intelligent Transport Systems, World Congress on Intelligent Transport Systems (ITS), 2008Conference paper (Refereed)
  • 3219.
    Alam, Joy Alam
    KTH, School of Industrial Engineering and Management (ITM).
    Building business analytics capabilities to become data-driven energy retailers2017Independent thesis Advanced level (degree of Master (Two Years)), 30 credits / 45 HE creditsStudent thesis
  • 3220.
    Alam, Joy
    et al.
    KTH, School of Computer Science and Communication (CSC).
    Ljungehed, Jesper
    KTH, School of Computer Science and Communication (CSC).
    A comparative study of hybrid artificial neural network models for one-day stock price prediction2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Prediction of stock prices is an important financial problem that is receiving increased attention in the field of artificial intelligence. Many different neural network and hybrid models for obtaining accurate prediction results have been proposed during the last few years in an attempt to outperform the traditional linear and nonlinear approaches.

    This study evaluates the performance of three different hybrid neural network models used for one-day stock close price prediction; a pre-processed evolutionary Levenberg-Marquardt neural network, Bayesian regularized artificial neural network and neural network with technical- and fractal analysis. It was also determined which of the three outperformed the others.

    The performance evaluation and comparison of the models are done using statistical error measures for accuracy; mean square error, symmetric mean absolute percentage error and point of change in direction.

    The results indicate good performance values for the Bayesian regularized artificial neural network, and varied performance for the others. Using the Friedman test, one model clearly is different in its performance relative to the others, probably the above mentioned model.

    The results for two of the models showed a large standard deviation of the error measurements which indicates that the results are not entirely reliable.

  • 3221. Alam, M M
    et al.
    Barsoum, Zuheir
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Lightweight Structures.
    Jonsen, P
    Kaplan, A F H
    Haggblad, H A
    Influence of defects on fatigue crack propagation in laser hybrid welded eccentric fillet joint2011In: Engineering Fracture Mechanics, ISSN 0013-7944, E-ISSN 1873-7315, Vol. 78, no 10, p. 2246-2258Article in journal (Refereed)
    Abstract [en]

    Fatigue cracking of laser hybrid welded eccentric fillet joints has been studied for stainless steel. Two-dimensional linear elastic fracture mechanics analysis was carried out for this joint geometry for four point bending load. The numerical simulations explain for the experimental observations why the crack propagates from the lower weld toe and why the crack gradually bends towards the root. Lack of fusion turned out to be uncritical for the initiation of cracks due to its compressive stress conditions. The linear elastic fracture mechanics analysis has demonstrated in good qualitative agreement with fatigue test results that lack of fusion slightly (<10%) reduces the fatigue life by accelerating the crack propagation. For the geometrical conditions studied here improved understanding of the crack propagation was obtained and in turn illustrated. The elaborated design curves turned out to be above the standard recommendations.

  • 3222. Alam, M. M.
    et al.
    Barsoum, Zuheir
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Lightweight Structures.
    Jonsén, P.
    Kaplan, A. F. H.
    Häggblad, H. A.
    The influence of surface geometry and topography on the fatigue cracking behaviour of laser hybrid welded eccentric fillet joints2010In: Applied Surface Science, ISSN 0169-4332, E-ISSN 1873-5584, Vol. 256, no 6, p. 1936-1945Article in journal (Refereed)
    Abstract [en]

    Laser hybrid welding of an eccentric fillet joint causes a complex geometry for fatigue load by 4-point bending. The weld surface geometry and topography were measured and studied in order to understand the crack initiation mechanisms. The crack initiation location and the crack propagation path were studied and compared to Finite Element stress analysis, taking into account the surface macro-and micro-geometry. It can be explained why the root and the upper weld toe are uncritical for cracking. The cracks that initiate from the weld bead show higher fatigue strength than the samples failing at the lower weld toe, as can be explained by a critical radius for the toe below which surface ripples instead determine the main stress raiser location for cracking. The location of maximum surface stress is related to a combination of throat depth, toe radius and sharp surface ripples along which the cracks preferably propagate.

  • 3223. Alam, M. M.
    et al.
    Kaplan, A. F. H.
    Tuominen, J.
    Vuoristo, P.
    Miettinen, J.
    Poutala, J.
    Näkki, J.
    Junkala, J.
    Peltola, T.
    Barsoum, Zuheir
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Analysis of the stress raising action of flaws in laser clad deposits2013In: Materials and Design, ISSN 0261-3069, Vol. 46, p. 328-337Article in journal (Refereed)
    Abstract [en]

    Fatigue cracking of laser clad cylindrical and square section bars depends upon a variety of factors. This paper presents Finite Element Analysis (FEA) of the different macro stress fields generated as well as stress raisers created by laser cladding defects for four different fatigue load conditions. As important as the defect types are their locations and orientations, categorized into zero-, one- and two-dimensional defects. Pores and inclusions become critical close to surfaces. The performance of as-clad surfaces can be governed by the sharpness of surface notches and planar defects like hot cracks or lack-of-fusion (LOF) are most critical if oriented vertically, transverse to the bar axis. The combination of the macro stress field with the defect type and its position and orientation determines whether it is the most critical stress raiser. Based on calculated cases, quantitative and qualitative charts were developed as guidelines to visualize the trends of different combinations.

  • 3224. Alam, Minhaj M
    et al.
    Barsoum, Zuheir
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Lightweight Structures.
    Häggblad, Hans Åke
    Jonsén, Pär
    Kaplan, Alexander
    The Effects of Surface Topography and Lack of Fusion on The Fatigue Strength of Laser Hybrid Welds2009In: Congress proceedings: ICALEO, 28th International Congress on Applications of Lasers & Electro-Optics, 2009, p. 38-46Conference paper (Refereed)
    Abstract [en]

    The geometrical aspects of laser hybrid welds (before, during and after the process) differ from autonomous laser welding and from arc welding. When studying the fatigue behaviour of laser hybrid welded fillet joints we identified that the micro-topography (i.e. the surface ripples) can be more important than the macrogeometry of the weld surface or lack of fusion (LOF), which frequently was detected. The plastic replica method was applied to measure the toe radii at the weld edges while the micro-topography was identified by interferometric profilometry. From metallurgical analysis of the joint interface, the tendency to LOF can be explained. Stress analysis was carried out by Finite element analysis (FEA) for the complex joint geometry and a bending load situation, showing maximum stress on the weld toes, even when including LOF. It was shown that the position and value of the maximum stress depends on a non-trivial combination of the weld geometry, including possible LOF, and the surface micro-topography. Thus it can be explained that at compressive stress conditions LOF does not contribute significantly to the fatigue strength of laser hybrid welds while the surface topography does. Recommendations for defining and in turn avoiding critical geometrical aspects during the welding process are discussed.

  • 3225. Alam, Minhaj M
    et al.
    Barsoum, Zuheir
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Lightweight Structures.
    Jonsén, Pär
    Häggblad, Hans Åke
    Kaplan, Alexander
    Fatigue behaviour study of laser hybrid welded eccentric fillet joints – Part II: State-of-the-art of fracture mechanics and fatigue analysis of welded joints2009In: 12th NOLAMP proceeding 2009: Nordic Laser Materials Processing Conference / [ed] Erling Dam Mortensen, 2009Conference paper (Other academic)
    Abstract [en]

    Simplified fatigue and fracture mechanics based assessment methods are widely used by the industry to determine the structural integrity significance of postulated cracks, manufacturing flaws, service-induced cracking or suspected degradation of engineering components under normal and abnormal service loads. In many cases, welded joints are the regions most likely to contain original fabrication defects or cracks initiating and growing during service operation. The welded joints are a major component that is often blamed for causing a structure failure or for being the point at which fatigue or fracture problems initiate and propagate. Various mathematical models/techniques for various classes of welded joints are developed by analytically or by simulation software's that can be used in fatigue and fracture assessments. This literature survey compiled useful information on fracture and fatigue analysis of various welded joints. The present review is divided into two major sections- fracture mechanics and fatigue analysis with widely used models. A survey table is also introduced to get the outlook of research trend on fatigue and fracture over last 3 decades. Although tremendous research effort has been implemented on fatigue and fracture analysis of conventional welding, research on relatively new welding technology (laser welding, hybrid laser welding) is still limited and unsatisfactory. In order to give guarantee or make welding standard for new welding technology, further research is required in the field of fatigue and fracture mechanics including FEM and multi-scale modeling.

  • 3226. Alam, Minhaj M
    et al.
    Barsoum, Zuheir
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Lightweight Structures.
    Jonsén, Pär
    Häggblad, Hans Åke
    Kaplan, Alexander
    Geometrical Aspects of The Fatigue Behaviour of Laser Hybrid Fillet Welds2009In: Proceedings of the Fatigue Design Conference, 2009Conference paper (Refereed)
  • 3227. Alam, Minhaj M
    et al.
    Barsoum, Zuheir
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Lightweight Structures.
    Josén, Per
    Häggblad, Hans Åke
    kaplan, Alexander
    Fatigue Behaviour Study of Laser Hybrid Welded Eccentric Fillet Joints - Part I2009In: 12th NOLAMP proceeding 2009: Nordic Laser Materials Processing Conference / [ed] Erling Dam Mortensen, 2009Conference paper (Other academic)
    Abstract [en]

    Welded joints are a major component that is often responsible for causing a structure failure or for being the point at which fatigue cracking initiates and propagates. Despite tremendous research efforts, the understanding of fatigue behaviour is still limited, particularly for new techniques like laser hybrid welding. Beside a comprehensive state-of-the-art study, the paper presents a fatigue study of laser hybrid welded eccentric fillet joint of stainless steel of 10 mm thickness, with 5 mm displacement. Motivation is to study the influence of the surface geometry shape on fatigue performance under a four point bending test. 13 samples were produced, measuring the toe radii and testing under constant amplitude loading with stress ratio R=0. Different techniques have been used to measure local weld geometry, like plastic replica, a 3D optical profiler and a 3D-digitizer. The influence of the local weld geometry, like the toe radii, on the stress concentration was studied by FE-analysis. Occasionally lack of fusion was observed, which was taken into account in the FE-analysis. Based on the nominal stress approach, SN-curves were designed for laser hybrid welded eccentric fillet joints. Macro hardness tests were carried out and the crack surfaces were observed in order to detect crack initiation and propagation. Correlations between the toe radii, the corresponding stress maxima and crack initiation locations were studied between the different samples and even along the welds.

  • 3228.
    Alam, Mohammad Faiz
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Evaluating the benefit-cost  ratio of groundwater abstraction for additional irrigation water on global scale.2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Projections show that to feed a growing population which is expected to reach 9.1 billion in 2050 would require raising overall food production by some 70 percent by 2050. One of the possible ways to increase agricultural production is through increasing yields by expanding irrigation. This study assesses the potential costs and benefits associated with sustainable groundwater abstraction to provide for irrigation.The feasibility of groundwater abstraction is determined using a combination of three indicators:groundwater recharge, groundwater quality (salinity) and sustainability (no depletion). Global groundwater recharge estimates used, are simulated with the Lund-Potsdam-Jena dynamic global vegetation model with managed lands (LPJmL). The cost of groundwater abstraction is determinedon a spatially explicit scale on global level at a grid resolution of 0.5°. Groundwater abstraction cost is divided into two parts: capital costs and operational costs. The potential benefit of increased water supply for irrigation is given by the water shadow price which is determined by using a Model of Agricultural Production and its Impact on the Environment (MAgPIE). The water shadow price for water is calculated in areas where irrigation water is scarce based on the potential increase in agricultural production through additional water and it reflects the production value of an additional unit of water. The water shadow price is given on a 0.5° grid resolution in US $/m3. Combining the cost of abstraction and the water shadow price, the benefit cost ratio is calculated globally on a spatially explicit scale to determine where investment in groundwater irrigation wouldbe beneficial. Finally, the results are analysed in global, regional and country perspectives. The results show that groundwater abstraction is beneficial for an area of 135 million hectares which is around 8.8% of the total crop area in the year 2005. Europe show the highest potential with an area of ~ 50 million hectares with a majority of the area located in France, Italy, Germany and Poland. Second is North America with an area of ~ 43.5 million hectares located in the Eastern states where the irrigation infrastructure is less developed as compared to the Western states. Sub-Saharan Africa shows a potential of ~ 15.4 million hectares in the Southern and Eastern countries of Zimbabwe, Kenya, Malawi, Tanzania, Ethiopia and some parts of South Africa. South Asia despite extensive groundwater extraction shows only a moderate potential of ~ 9 million hectares, mostly located in India whereas China shows almost no potential. This is due to extensive groundwater depleted areas which were removed from the analysis and low water shadow prices which made abstraction not beneficial. Well installation costs play an important role in developing countries in regions of Sub-Saharan Africa and South Asia, where a reduction in costs would lead to an increase in area by more than 30%. Subsidy analyses shows that substantial increase in crop land areas where a benefit cost ratio >1 takes place in India with subsidised energy prices but this effect is found to be negligible in Mexico. This study is, to the author’s knowledge, the first to assess the benefit cost ratio of groundwater abstraction on a global scale by determining spatially explicit abstraction costs. The results show that a great potential for groundwater abstraction exists in all regions despite problems of groundwater depletion due to disparity in distribution and development of groundwater resources. Energy subsidies and cheap well installation techniques are the two factors that could bring down the abstraction costs which are quite important in developing regions where farm incomes are low. Also, groundwater irrigation potential not only exists in arid areas of Africa and South Asia where irrigation is needed but also in humid areas of Europe and North America where groundwater irrigation can play an important role in building resilience to events of drought. However, it is essential to not to follow the path that has led to groundwater depletion in many parts of the world and develop this potential in a sustainable way through groundwater use regulations, policies and efficient technologies.

  • 3229.
    Alam, M.S.
    et al.
    Memorial University of Newfoundland, Canada.
    Ahmed, Kazi Matin
    University of Dhaka, Bangladesh.
    Hasan, M.A.
    University of Dhaka, Bangladesh.
    Hossain, Muhammed
    KTH, School of Architecture and the Built Environment (ABE), Land and Water Resources Engineering (moved 20130630), Environmental Geochemistry and Ecotechnology.
    Bhattacharya, Prosun
    KTH, School of Architecture and the Built Environment (ABE), Land and Water Resources Engineering (moved 20130630), Environmental Geochemistry and Ecotechnology.
    Controls of sedimentary facies on arsenic mobilization in shallow aquifers of the Matlab North Upazila, southeastern Bangladesh2013Conference paper (Other academic)
    Abstract [en]

    Groundwater extracted from shallow (<100 m bgl) Holocene alluvial aquifers, is the primary source of drinking water in Matlab North Upazila, Southeast Bangladesh. The distribution of lithofacies and its relation to hydrochemistry in such heterogeneous deposits are of fundamental importance for the analysis of groundwater quality. Aquifer sediment samples were collected from 48 locations throughout the study area. Lithofacies distribution was characterized using grain size and sediment colors. Channel fills (sandy) and over bank (silt-clay) deposits the two main lithofacies groups, were identified. These sandy deposits represent an active meandering river or channel fills sediment sequence, which are usually capped by silts and clays of an over bank sediment sequence. All the collected sediments samples were generalized and subdivided based on four distinct color variations, such as Black, White, Off-white, and Red according to Munsell color chart and water-well drillers’ perception.

    Mineral compositions showed variability with the sediment color and grain size. Red and off-white sediments contain fewer amounts of metastable minerals (hornblende, actinolite, kyanite and pyroxenes etc.) than that of black sediments, whereas black sediments contain higher amount of biotite. The relatively high content of biotite and other dark colored ferromagnesian minerals are responsible for the black and grayish color of these sediments. Ferruginous coating on silicates, particularly on quartz grains, gives the red and off-white coloration. Based on the available information regarding sediment colors of aquifers in which tubewell screens were placed, 44 domestic hand pumped tubewells (HTWs) were selected for water sampling. The groundwater abstracted from black sediments of shallow aquifer showed higher concentrations in DOC (median: 5.81 mg/L), dissolved NH

    4+ (median: 3.47 mg/L), PO43- (median: 1.36 mg/L), Fe (median: 4.87 mg/L), As (median: 252.53 μg/L) and relatively low Mn (median: 0.54 mg/L) and SO42-(median: 0.59 mg/L) concentrations, whereas groundwater abstracted from off-white and red sediments of shallow aquifer showed lower concentrations in DOC (median: 1.95 and 1.71 mg/L, respectively), dissolved NH4+ (median: 0), PO43- (median: 0.14 and 0.04 mg/L, respectively), Fe (median: 2.25 and 0.63 mg/L, respectively), As (median: 17.36 and 15.05 μg/L, respectively) and relatively high Mn+2 (median: 1.12 and 1.15 mg/L, respectively) and SO42- (median: 0.79 and 0.78 mg/L, respectively) concentrations. The water samples collected from black sediments (median Eh: 211 mV) indicated most reducing environment, followed by white (median Eh: 227 mV), whereas off-white and red sediments (median Eh: 268 and 274 mV) signified less reducing environment. The study supports that the sediment colors in shallow aquifer can be a reliable indicator of high and low-As concentrations and can be a useful tool for local drillers to target arsenic safe aquifers.

  • 3230. Alam, Samina
    et al.
    Hasan, Mashooda
    Saeed, Sadaf
    Fischer, Andreas
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Inorganic Chemistry.
    Khan, Naeema
    cis-(9S,10S)-Methyl 1-propyl-1,2,3,4-tetrahydro-beta-carboline-3-carboxylate2008In: Acta Crystallographica Section E: Structure Reports Online, ISSN 1600-5368, E-ISSN 1600-5368, Vol. 64, p. O361-U1624Article in journal (Refereed)
    Abstract [en]

    The title compound, C16H20N2O2, was synthesized from ( S)tryptophan methyl ester hydrochloride and butyraldehyde. The absolute configuration 9S, 10S was assigned on the basis of the unchanging chirality of the C9 centre. The NH group of the indole ring is involved in intermolecular N-H center dot center dot center dot O hydrogen bonding, while the NH group of the six-membered ring is not. This latter ring has a half-chair conformation.

  • 3231. Alam, Samina
    et al.
    Hasan, Mashooda
    Saeed, Sadaf
    Fischer, Andreas
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Inorganic Chemistry.
    Khan, Naeema
    trans-(1R,3S)-methyl 1-methyl-1,2,3,4-tetrahydro-beta-carboline-3-carboxylate2007In: Acta Crystallographica Section E: Structure Reports Online, ISSN 1600-5368, E-ISSN 1600-5368, Vol. 63, p. O871-O872Article in journal (Refereed)
    Abstract [en]

    The title compound, C14H16N2O2, was obtained from the reaction between S-tryptophan methyl ester hydrochloride and acetaldehyde. The molecule adopts a trans configuration, with the methyl and methoxycarbonyl groups located on opposite sides of the central tetrahydro-beta-carboline unit. Bifurcated intermolecular N-H...O/N hydrogen bonds link the molecules into chains.

  • 3232. Alam, Samina
    et al.
    Saeed, Sadaf
    Fischer, Andreas
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Inorganic Chemistry.
    Khan, Naeema
    Methyl 2-(2-hydroxyacetamido)benzoate2010In: Acta Crystallographica Section E: Structure Reports Online, ISSN 1600-5368, E-ISSN 1600-5368, Vol. 66, p. O913-U2993Article in journal (Refereed)
    Abstract [en]

    The title compound, C10H11NO4, was formed from 4,1-benzoxazepine-2,5(1H,3H)-dione and ammonia gas. Intramolecular hydrogen bonding is present between the amide N-H group and the carbonyl O atom of the ester group. The crystal structure features intermolecular O-H center dot center dot center dot O hydrogen bonds.

  • 3233.
    Alam, Samiul
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Recurrent neural networks in electricity load forecasting2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In this thesis two main studies are conducted to compare the predictive capabilities of feed-forward neural networks (FFNN) and long short-term memory networks (LSTM) in electricity load forecasting.

    The first study compares univariate networks using past electricity load, as well as multivariate networks using past electricity load and air temperature, in day-ahead load forecasting using varying lookback periods and sparsity of past observations. The second study compares FFNNs and LSTMs of different complexities (i.e. network sizes) when restrictions imposed by limitations of the real world are taken into consideration.

    No significant differences are found between the predictive performances of the two neural network approaches. However, adding air temperature as extra input to the LSTM is found to significantly decrease its performance. Furthermore, the predictive performance of the FFNN is found to significantly decrease as the network complexity grows, while the predictive performance of the LSTM is found to increase as the network complexity grows. All the findings considered, we do not find that there is enough evidence in favour of the LSTM in electricity load forecasting.

  • 3234.
    ALAM, SHABNAM
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.), Industrial Management.
    Towards a Value Driven Transformation2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This thesis brings up the phenomenon of manufacturing companies transforming themselves to become product and service oriented companies. The thesis aims to discuss the importance of customer support service as a competitive advantage during such transformation process. Earlier research has been focused on the advantages and general challenges with adding services to the core products, but what is lacking is to what extent these offerings fulfil the true needs of the customers as combined offerings result in increased complexity of the development, production, delivery and support processes. As the customer support is the most ignored factor among transforming manufacturing companies, it becomes crucial to highlight the importance of it as a key factor to gain competitive advantage. Thus the aim is to answer: What complications are there in succeeding with the customer support service for transforming manufacturing companies towards services?

    To understand what role the customer support service has in relation to transforming manufacturing companies, a case study is conducted at Scania CV AB. The company is offering among other services, the Fleet Management service which is sold together with the vehicles as a way to offer total solutions and become this way service oriented. In Scania´s case, it is the service salesmen at Scania retail organisations that are aimed to act as a first line support towards the customers. Therefore the aim is to investigate and analyse the complications the service salesmen are faced with in supporting their customers. More specifically, the customer´s perspective is studied from the internal organisational view to better visualise the role of the customer support service in relation to the transformation towards services. The study shows that there shouldn´t exist any service without any centralised customer support function as increased sales of services has resulted in increased need for an efficient support service and the fact that the customers base their perceived value on the value-in-use of the offerings. It was further found that the service salesmen need improved IT skills and support from the authorities in terms

    of tools and strategies to obtain an effective value communication of the total solution and this way sustain a professional customer relationship.

  • 3235.
    Alam, Shabnam
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Huaiquio, José
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Materialanskaffning av emballage på Scania2012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Are storage facilities a burden or an asset? In earlier times storage was regarded simply as a means to ensure reliable delivery. Today the additional complexity of being a fixed cost, that must be minimized, has risen. Scania CV AB was founded in 1900 originally as a bicycle manufacturer. It has now evolved to a global heavy duty vehicle and marineengines manufacturer. The company has its own packaging, which is used to facilitateproduction, distribution of goods, components, and spare parts. Striving for continuous improvements is explicitly emphasized in Scania’s mission statement. For packaging, a possible improvement can be achieved by gaining further insight into the companies packaging flow and ordering policies. Hence, the aim of this project is to map Scania’s package flow and to find plausible suggestions for how packaging management can be improved to avoid storage excess. A qualitative method consisting of empirical and literature studies is used to gain a deeper insight of logistics as a subject matter. Observations are made through private guided tours of three departments at Scania, namely engine manufacturing, packaging disposal and the main warehouse. The results show that material and packaging management at Scania must obtain better information flow from each intermediate station in the packaging flow. The packaging flow is vast and complex. Thus, a first step for improvement could most likely be to improve the internal information flow. Subsequently, the improved internal flow should be extended to improve the communication with suppliers.

  • 3236.
    Alam, Sheikh Ariful
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Transport and Location Analysis.
    Evaluation of the potential locations for logistics hubs: A case srudy for a logistics company2013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The location of logistics hubs is one of the most crucial success factors for potential economic

    growth in logistics sector. Since the logistics hub has direct and indirect impacts on different

    stakeholders including investors, policy makers, infrastructure providers, hub operators, hub

    users and the community itself, it needs to be considered carefully. Therefore, logistics hubs

    should be located in such a way that it can provide a better accessibility to three different modes

    of transportation- road, rail and waterways. The aim of this study is to evaluate the potential

    locations for logistics hubs and to find out the criteria that affect for the selection of location for

    logistics hubs. A comprehensive literature study reveals the factors that are affecting the

    selection of location for logistics hubs and the methods to evaluate those locations considering

    the criteria. Location selection or evaluation is a typical multi-criteria decision making (MCDM)

    problem in which performance criteria plays a vital role for the final decision making. Both

    qualitative and quantitative MCDM methods are applied in this study, where the Analytic

    Hierarchy Process (AHP) is qualitative and the gravity method is quantitative method. Analytic

    Hierarchy Process (AHP) is a structured approach to reach the final decision which is one of the

    best methods of all MCDM problems, used in recent literature to evaluate the location selection

    problems. A case study is done for the logistics company, Brinova Fastigheter AB in Sweden.

    This study is followed by AHP method which is considered with selected factors, i.e. highway

    accessibility, intermodal capacity, port capacity and land availability. Moreover, this study is

    conducted by evaluating the four major potential locations in Sweden i.e. Stockholm, Göteborg,

    Helsingborg and Karlshamn for selecting as a logistics hub. Besides, the location for selecting

    logistics hubs is evaluated by the gravity method, which is a quantitative method to determine

    the level of accessibility for the selected locations, considering the flow of goods both inbound

    and outbound and the transport cost between the locations. The result from the AHP method

    recommend that Göteborg is the best potential location to establish logistic hub whereas the

    Gravity model represents that Stockholm has the highest level of accessibility for logistics

    activity. Therefore the study suggested that both Göteborg and Stockholm are considered to be

    the best potential locations considering in present situation

  • 3237.
    Alamaa, Angelica
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
    High-speed railway embankments: a comparison of different regulation2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Swedish transport administration initiated this Master Thesis project and the aim was to compare regulations for the design of high-speed railways from three European countries: France, Germany and Spain. The reason why this is of interest for the Swedish transport administration is the design of the first Swedish high-speed railway, called Ostlänken. Therefore, a literature study of the regulations and other literature regarding high-speed railway has been carried out. A basic description of railway components, slab track and ballasted tracks is presented.

    Ballasted embankments usually consist of a trackbed layer (ballast onto subballast), and the ultimate thickness of this layer is discussed, as there are a number of methods available to calculate the appropriate thickness, with a number of different design parameters. These design methods results in different trackbed thickness and choosing the “wrong” method might lead to an overestimation or underestimation of the trackbed layer. Constructing a ballastless railway line means that the ballast is replaced by another material, usually a slab made of reinforced concrete or asphalt, and the rail is cast onto this slab. Countries design their slab using different methods. Germany has constructed high-speed railway lines with a slab track solution, generally slabs with low flexible stiffness. France has until recently constructed their high-speed line ballasted but is now developing a new slab track technique, called NBT (New Ballastless Track) and Spain uses various methods.

    It is difficult to compare the regulations, however, there are some factors that at least begin to explain the differences between the countries: the frost hazard, the inherent ground quality, purpose with the railway (mixed traffic, solely passenger traffic, etc.), design parameters (life, axle load, etc.). Furthermore, the settlement requirements, soil classification and bearing capacity are factors that varies from country to country, but the origin for this variation is harder to detect.

  • 3238.
    Alameddine, Raged
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Dashtbozorg, Sajad
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Utredning av för- och nackdelar med TN-S respektive TN-C system2016Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In this report analysis the advantages and disadvantages of the TN-C (four conductor system) and TN-S (five conductor system) system. There are different opinion about which system is most appropriate to use in the distribution network and the building main lines. With the help of literature studies and contacts with various power companies and electric companies different opinion have been discussed . TN-C is the most appropriate option in the distribution network and TN-S should be used in the building main lines. This for achieving high and stable electrical environment. This thesis will facilitate the choice of technology and hopefully increase the knowledge about the subject.

  • 3239. Alameldin, A.
    et al.
    El-Gabry, L. A.
    Fridh, Jens
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Saha, Ranjan
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    CFD analysis of suction and pressure side film cooling influence on vane aero performance in a transonic annular cascade2014In: Proceedings of the ASME Turbo Expo, 2014Conference paper (Refereed)
    Abstract [en]

    Operating at temperatures well above their melting point, gas turbines' components are subject to terribly high thermal stresses. In order to keep them intact and performing, different cooling techniques are implemented. One of these methods is film cooling. Film cooling implementation in vane cascades has a potential loss expense. Proper assessment of its impact on the vane performance has to be conducted. The CFD approach of modeling each hole and cooling tube autonomously is very computationally expensive. In the current work an assessment of a new, more computationally efficient CFD approach for modelling film cooling was conducted on a vane cascade operating in the transonic regime (M =0.89). The film cooling holes were represented by orifice boundary condition at the vane surface, omitting the need to model internal coolant plenum and cooling tubes mesh, resulting in 180% reduction in grid size and attributed computational cost interpreted in 300% saving in computation time. Uncooled, and film cooled with different configurations and at different blowing ratios (BR) simulations were performed and compared to experimental measurements. A good agreement was obtained for the exit flow angles, vorticity and aerodynamic loss for all the cases (uncooled and cooled). Pitch-averaged exit flow angle outside endwalls regions remains unchanged for all cooling configurations and blowing ratios. The aerodynamic loss was found to be more sensitive to increasing the blowing ratio on the suction side than on the pressure side. The proposed approach of coolant injection modeling is shown to yield reliable results, within the uncertainty of the measurements in most cases. Along with lower computational cost compared to conventional film cooling modeling approach, the new approach is recommended for further analysis for aero and thermal vane cascade flows.

  • 3240.
    Alander, B.
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Polymeric Materials.
    Capezza, A.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Polymeric Materials. Department of Plant Breeding, The Swedish University of Agricultural Sciences, Box 101, Alnarp, Sweden.
    Wu, Q.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH).
    Johansson, E.
    Olsson, Richard T.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH).
    Hedenqvist, Mikael
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH).
    A facile way of making inexpensive rigid and soft protein biofoams with rapid liquid absorption2018In: Industrial crops and products (Print), ISSN 0926-6690, E-ISSN 1872-633X, Vol. 119, p. 41-48Article in journal (Refereed)
    Abstract [en]

    A novel and facile method to produce inexpensive protein biofoams suitable for sponge applications is presented. The protein used in the study was wheat gluten (WG), readily available as a by/co-product, but the method is expected to work for other cross-linkable proteins. The foams were obtained by high-speed stirring of pristine WG powder in water at room temperature followed by drying. Glutaraldehyde was used to crosslink the foam material in order to stabilize the dispersion, reduce its tackiness and improve the strength of the final foam. The foams were of medium to high density and absorbed readily both hydrophobic and hydrophilic liquids. The foam structure, consisting primarily of an open pore/channel system, led to a remarkably fast capillary-driven (pore-filling only) uptake of a hydrophobic liquid (limonene). Essentially all uptake occurred within the first second (to ca. 90% of the dry weight). In a polar liquid (water), the rapid pore-filling occurred in parallel with a more time-dependent swelling of the foam matrix material. Further improvement in the foam strength was achieved by making a denser foam or adding TEMPO-oxidized cellulose nanofibres. Soft foams were obtained by adding glycerol.

  • 3241.
    Alander, Björn
    KTH, School of Chemical Science and Engineering (CHE).
    Rigid gluten foams formed at ambient conditons2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    A new method based on mechanical foaming to produce renewable foam materials based on gluten, i.e. without using freeze-drying, using high shear mixing and stabilizing the foam using glutaraldehyde is presented. An optimization of the amount of glutaraldehyde is shown and then three ways to tailor the mechanical properties of the foams are evaluated, including increasing the gluten content in the system, adding TEMPO-oxidised cellulose as reinforcement or adding glycerol for plasticization. One system using both the TEMPO cellulose and glycerol combined was also analyzed. The mechanical properties and morphology of the foams were analyzed with compression tests and scanning electron microscopy (SEM). The results shows that foams can be obtained using the method with an optimal glutaraldehyde concentration of 0.25g/10g gluten, resulting in rigid foams with 50-70% porosity and a pore size of 0.25-0.30 mm. Increasing gluten content or adding TEMPO cellulose results in stronger foams with a higher modulus, while glycerol can be added to increase ductility and strain recovery. Combining TEMPO cellulose with glycerol in the foam resulted in weaker materials than for similar samples with only glycerol.

  • 3242. Alander, E. M.
    et al.
    Rasmuson, Åke C.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Transport Phenomena.
    Mechanisms of crystal agglomeration of paracetamol in acetone-water mixtures2005In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 44, no 15, p. 5788-5794Article in journal (Refereed)
    Abstract [en]

    The mechanisms governing the influence of the solvent composition on the agglomeration in a crystallization process have been investigated. Narrowly sieved paracetamol crystals were suspended in supersaturated acetone-water solutions, and were allowed to grow at isothermal conditions, after which the agglomeration was recorded. In all experiments the same sieve size fraction was used as well as the same magma density. In each experiment the supersaturation was kept constant. Experiments were performed in different solvent compositions at different supersaturation, crystal growth rate, solution viscosity, and agitation rate. For a statistically sufficient number of particles from each experiment, the number of crystals in each product particle was determined by image analysis and multivariate data evaluation. From the resulting number distributions of crystals per product particle, parameters defining the degree of agglomeration were extracted. The experimental results clearly establish that there is an influence of the solvent composition on the degree of agglomeration, which cannot be explained by differences in crystal growth rate, or differences in solution viscosity. The degree of agglomeration is found to decrease with increasing solvent polarity. It is, suggested that the mechanism by which the solvent influence relates to the crystal-solvent interaction and the physicochemical. adhesion forces between crystals in the solution.

  • 3243. Alander, E. M.
    et al.
    Uusi-Penttila, M. S.
    Rasmuson, Åke C.
    KTH, Superseded Departments, Chemical Engineering and Technology.
    Characterization of paracetamol agglomerates by image analysis and strength measurement2003In: Powder Technology, ISSN 0032-5910, E-ISSN 1873-328X, Vol. 130, no 03-jan, p. 298-306Article in journal (Refereed)
    Abstract [en]

    Paracetamol is crystallized in different solvents and techniques are developed and used to characterize the product. The product particles from three different solvent compositions: ethylene glycol, acetone and an acetone-water mixture (30-70 wt.%) have been examined. Product properties visually observed are quantified by image analysis and evaluation of measured image descriptors with Principal Component Analysis (PCA). The agglomerate strength has been determined by crushing single agglomerates. Depending on the solvent, the content of single crystals and agglomerates differ. Agglomerates differ by the number and size of crystals grown together, as well as by the strength.

  • 3244. Alander, Eva M.
    et al.
    Rasmuson, Åke C.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Transport Phenomena.
    Agglomeration and adhesion free energy of paracetamol crystals in organic solvents2007In: AIChE Journal, ISSN 0001-1541, E-ISSN 1547-5905, Vol. 53, no 10, p. 2590-2605Article in journal (Refereed)
    Abstract [en]

    The agglomeration of paracetamol during crystallization in different pure solvents has been investigated. Narrowly sieved crystals were suspended as seeds and allowed to grow and agglomerate at constant supersaturation and temperature. Particles from each experiment were examined by image analysis and multivariate data evaluation, for the number of crystals per particle. From the resulting number distribution, parameters defining the degree of agglomeration were extracted. The degree of agglomeration among the product particles is fairly low in water, methanol, and ethanol, while it is substantial in acetone particularly, but also in acetonitrile and methyl ethyl ketone. Surfaces of large, well-grown paracetamol crystals have been characterized by contact angle measurements. The surface free energy components of different crystal faces have been estimated using Lifshitz-van der Waals acid-base theory. The data are used for estimation of the solid-liquid interfacial free energy of each face in the solvents of the agglomeration experiments and the corresponding crystal-crystal adhesion free energy of pairs of faces. The degree of agglomeration in different solvents does correlate to the free energies of adhesion. This supports the hypothesis that the influence of the solvent on the crystal agglomeration relates to physico-chemical adhesion forces between crystal faces in the solution.

  • 3245.
    Alander, Jarmo
    et al.
    Department of Electrical Engineering and Automation, University of Vaasa.
    Autere, Antti
    Department of Electrical Engineering and Automation, University of Vaasa.
    Kanniainen, Olli
    Department of Electrical Engineering and Automation, University of Vaasa.
    Koljonen, Janne
    Department of Electrical Engineering and Automation, University of Vaasa.
    Nordling, Torbjörn E M
    Department of Electrical Engineering and Automation, University of Vaasa.
    Välisuo, Petri
    Department of Electrical Engineering and Automation, University of Vaasa.
    Near infrared wavelength relevance detection of ultraviolet radiation-induced erythema2008In: Journal of Near Infrared Spectroscopy, ISSN 0967-0335, E-ISSN 1751-6552, Vol. 16, no 3, p. 233-241Article in journal (Refereed)
    Abstract [en]

    The acute effects of sun-bathing on the near-infrared absorption spectra of human skin were studied by exposing the shoulders of a male test subject to bright Finnish high summer mid-day sun. The spectra were measured before, immediately after and for several days after exposure. Four different spectral. processing and classification methods were applied to the data set to identify differences caused by exposure to the sun. The spectrophotometer and measuring procedure were found to cause some systematic errors, calling for further development, even though they could, to a large extent, be compensated for computationally. Spectral regions indicating ultraviolet radiation-induced erythema were Located and the degree of erythema could be predicted correctly but the signal is weak. This paper discusses promising wavelength selection methods to study the dermal effects of exposure to the sun, as well as difficulties and remedies of near infrared spectroscopic measurements of the skin.

  • 3246.
    Alanis Jimenez, Ana Karen
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment.
    Influencing Factors on Cycling to School Among Young Adults: Case Study- The Netherlands2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Cycling is an important source of regular physical activity and an equitable mode of transport for reaching the recommended daily hour of activity. This research focusses on gaining insights in the travel behavior of young adults (12-20 years old) and the influencing factors within students from the Dutch provinces of Lim- burg, Overijssel and Noord-Brabant, in order to stimulate cycling among this group.

    Two sets of data were used for this research, the OViN data with 4116 young adults in the Netherlands in 2016 that kept track of all of their out-of-home trips during one day; and a tailored made survey with 592 respondents that was distributed among different secondary and upper secondary schools from the three provinces. Based on two different sets of data, different models were set up explaining the level of influence of the personal characteristics, household character- istics, social, built and natural environment on the cycling behavior of young adults.

    The results indicate that older teenagers are less likely to cycle than younger teenagers and that the purpose of the trip also strongly influences the mode choice. Other personal, household, social and built environment characteristics such as ethnicity, household size, disposable income, friends’ behavior, distance and level of urbanization are also found to have explanatory power. Within the research, different models are set up explaining the influencing variables and the level of influence of the variables analyzed. Based on the findings, measures and incentives can be set up to stimulate the cycling behavior of teenagers.

  • 3247.
    Alaniz Flores, Monica
    KTH, School of Electrical Engineering (EES), Space and Plasma Physics.
    Experiment Control Electronics for Spinning Quad Ionospheric Deployer SQUID2011Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The Spinning QUad Ionospheric Deployer (SQUID) is a soundingcrocket experiment developed to test and verify a novel mechanism to deploy wire booms. The SQUID consists of the Rocket Mounted Unit (RMU) and the Free Flying Unit (FFU), the former is attached to the rocket and the latter is ejected. The FFU carries the electronics box (eBox) that controls the system and the boom deployment system known as SCALE. The FFU needs to be independent when has been ejected from the rocket. This thesis work covers the design and manufacture of the SQUID electronics system to control the functionality of the experiment. The control is implemented in a Field Programmable Gate Array (FPGA) using the VHDL language. The integration, testing and validation of software and hardware also is presented here. The SQUID experiment was launched onboard the REXUS-10 rocket from ESRANGE the 23rd February 2011.

  • 3248.
    Alaniz, Monica
    et al.
    KTH, School of Engineering Sciences (SCI), Mechanics, Structural Mechanics.
    Belyayev, Serhiy
    KTH, School of Engineering Sciences (SCI), Mechanics, Structural Mechanics.
    Bergman, David
    Casselbrant, Gustav
    KTH, School of Engineering Sciences (SCI), Mechanics, Structural Mechanics.
    Honeth, Mark
    KTH, School of Engineering Sciences (SCI), Mechanics, Structural Mechanics.
    Huang, Jiangwei
    KTH, School of Engineering Sciences (SCI), Mechanics, Structural Mechanics.
    Ivchenko, Nickolay
    KTH, School of Electrical Engineering (EES), Space and Plasma Physics.
    Laukkanen, Mikko
    KTH, School of Engineering Sciences (SCI), Mechanics, Structural Mechanics.
    Michelsen, Jacob
    KTH, School of Engineering Sciences (SCI), Mechanics, Structural Mechanics.
    Pronenko, Vira
    KTH, School of Engineering Sciences (SCI), Mechanics, Structural Mechanics.
    Paulson, Malin
    KTH, School of Engineering Sciences (SCI), Mechanics, Structural Mechanics.
    Schlick, Georg
    KTH, School of Engineering Sciences (SCI), Mechanics, Structural Mechanics.
    Tibert, Gunnar
    KTH, School of Engineering Sciences (SCI), Mechanics, Structural Mechanics.
    Valle, Mario
    KTH, School of Engineering Sciences (SCI), Mechanics, Structural Mechanics.
    The SQUID sounding rocket experiment2011In: Proceedings of the 20th ESA Symposium on European Rocket and Balloon Programmes and Related Research, European Space Agency, 2011, p. 159-166Conference paper (Refereed)
    Abstract [en]

    The objective of the SQUID project is to develop and in flight verify a miniature version of a wire boom deployment mechanism to be used for electric field measurements in the ionosphere. In February 2011 a small ejectable payload, built by a team of students from The Royal Institute of Technology (KTH), was launched from Esrange on-board the REXUS-10 sounding rocket. The payload separated from the rocket, deployed and retracted the wire booms, landed with a parachute and was subsequently recovered. Here the design of the experiment and post fight analysis are presented.

  • 3249. Alanne, K.
    et al.
    Schade, J.
    Martinac, Ivo
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Services Engineering.
    Saari, A.
    Jokisalo, J.
    Kalamees, T.
    Economic viability of energy-efficiency measures in educational buildings in Finland2013In: Advances in Building Energy Research, ISSN 1751-2549, E-ISSN 1756-2201, Vol. 7, no 1, p. 120-127Article in journal (Refereed)
    Abstract [en]

    The economic viability of novel energy-efficient design concepts has been evaluated in Finnish educational buildings. The total energy consumption of representative target buildings with each design concept has been found using the whole-building simulation tool IDA Indoor Climate and Energy 4.0, and the financial viability has been assessed using the discounted payback period method. Different thermal insulation and air tightness properties of the building envelope, and different ventilation's heat recovery efficiency assumptions and heat distribution options have been investigated. The results suggest that a prudent attitude should be taken toward the investments in ultra-low-energy designs. Total energy-saving potential of 25-32% can be obtained. The payback periods varied from 15 to more than 40 years. The results can be generalized in cold climates and techno-economic conditions similar to Finland.

  • 3250.
    Alanne, Kari
    et al.
    Department of Energy Technology, Aalto University.
    Kari, Saari
    Department of Energy Technology, Aalto University.
    Mannu, Kuosa
    Department of Energy Technology, Aalto University.
    Md., Rahman
    Department of Energy Technology, Aalto University.
    Martin, Andrew
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Microgeneration and Desalination Using Rotary Steam Engine (RTE) Technology2011Conference paper (Refereed)
    Abstract [en]

    This paper discusses the conditions to develop a micro-cogeneration plant based on biomass-fuelled rotary steam engine (RSE). The use of RSE in micro-cogeneration is justifiable due to relatively high electrical efficiency, capability of applying versatile thermal sources and low operational temperatures and pressures. At steam temperatures 200…300ºC, the electrical efficiency of 20 % may be obtained with the electrical power varying between 1…20 kWe. The other advantages of an RSE are that it is lubricant free and the noise level is low. In residential applications, an RSE may be considered an alternative for Stirling Engines and internal combustion engines, when integrated into a hydronic heating system and electrical grid. Another promising adaptation is desalination. A solar-powered RSE micro-cogeneration system would provide an inexpensive option to supply fresh water and electricity for the rural areas in developing countries that have access to sea water. A 10 kWe RSE plant combined with a once-through multi-stage flash (MSF) distillation plant is estimated to have potential of producing pure water from 180 to 800 kg/h.

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