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14th NOLAMP Conference : The 14th Nordic Laser Materials Processing Conference, August 26th – 28th 2013, Gothenburg, Sweden
- 2013
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Editorial collection (other academic/artistic)abstract
- Laser is a key element in obtaining a sustainable economy in Europe. Innovative laser processes will play a significant role in future green manufacturing as they provide a precise, well-controlled and highly effective energy deposition to the workpiece. Future challenges are to increase the spectrum of laser manufacturing technologies in all sectors where the laser can offer innovative product solutions, higher product quality, less environmental impact, higher productivity and in turn cost benefits.The NOLAMP conferences address all aspects of laser materials processing from fundamental science to industrial applications. The first NOLAMP conference took place in Oslo in 1987 in a period of intense development of the laser processes and their industrial applications. The NOLAMP has continued on a biannual cycle ever since, strengthening the Nordic laser community by encouraging knowledge transfer and networking. Now, 26 years later, in the forthcoming 14th NOLAMP, the research and development of processes like laser welding, laser hybrid welding, laser cutting and laser surface treatment is still very important, as well as the development of industrial applications and equipment for laser material processing. This time the NOLAMP Conference will be held in Gothenburg, Sweden. In this highly industrialized region of Sweden and with the close distance to Denmark, Norway and Finland, we hope to attract a strong participation from industry and the scientific community. On behalf of the Nordic laser community and Luleå University of Technology, it is our great pleasure to invite you to the 14th NOLAMP conference.
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2011 Baltic Congress on Future Internet and Communications
- 2011
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Editorial proceedings (peer-reviewed)abstract
- The proceedings contain 36 papers. The topics discussed include: evolutionary future Internet service platforms enabling seamless cross layer interoperability; taxonomical approach to the deployment of traceback mechanisms; a novel model for social networks; quality of experience based optimization of heterogeneous multimedia sessions in IMS; aquarema in action: improving the YouTube QoE in wireless mesh networks; on synthesis of dependable MAC protocol for two real-world WSN applications; enterprise security perimeter - e-mail server protection; an ontology approach to development of inter IHS communication subsystem ontology for intrusion handling systems in wireless LANs; a comparative study on cost-benefit analysis of fiber-to-the-home telecommunications systems in Europe; calculation of transmission probability in heterogeneous ad hoc networks; and performance analysis of non-beaconed IEEE 802.15.4 for high-confidence wireless communications.
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2012 2nd Baltic Congress on Future Internet Communications
- 2012
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Editorial proceedings (peer-reviewed)abstract
- The following topics are dealt with: smart applications; next generation WLAN; broadband infrastructure; network performance; network security; user-centric solutions; wireless systems; Internet of things; smart spaces; analog integrated circuits; traffic analysis; SoC; routing; and protocols. © 2012 IEEE
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2016 Workshop on Exascale Multi/Many Core Computing Systems (E-MuCoCoS)
- 2016
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Editorial collection (peer-reviewed)abstract
- Exascale computing will revolutionize computational science and engineering by providing 1000x the capabilities of currently available computing systems, while having a similar power footprint. The HPC community is working towards the development of the first Exaflop computer after reaching the Petaflop milestone in 2008. There are concerns that computer designs based on existing multi-core and many-core solutions will not scale to Exascale considering technical challenges (such as, productivity, energy consumption or reliability) and reasonable economic constraints. Therefore, novel multi-core and many-core solutions are required to reach Exascale. The E-MuCoCoS workshop series focuses on multi/many core languages, system software and architectural solutions for extreme-scale systems towards Exascale.
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2021 Vehicle Dynamics seminar
- 2021
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Editorial proceedings (other academic/artistic)abstract
- The seminar is held annually. The full title of this year's seminar was "2021 Vehicle Dynamics seminar -- for Future Mobility ...and not only Lateral".
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3-D band-stop FSS for X-band and Ku-band
- 2017
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In: 2017 Progress In Electromagnetics Research Symposium - Fall (PIERS - FALL). - : Electromagnetics Academy. - 9781538612118 - 9781538612125 ; , s. 671-675
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Conference paper (peer-reviewed)abstract
- A 3-D Frequency Selective Surface (FSS) with band-stop characteristics for X-band and Ku-band is proposed. A 3-D FSS unit cell is constructed by analyzing two 2-D FSS's. The size of the 3-D FSS unit cell is 5 mm × 5 mm wherein two layers of FR4 substrate with respective widths of 0.762 mm and 0.5 mm are used. Dual stop bands are obtained with this FSS unit cell around 10 GHz and 17.4 GHz; where a wide stop-band of 5.2 GHz is obtained. The parametric study carried out on the proposed design in terms change in nature of substrate, alternate use of different substrates and variation in angle of incidence. The 3-D FSS shows its band rejection property X-band and Ku-band respectively. Ansoft HFSS commercial EM solver software is used to carry out the simulation work.
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34th EMS Summer School : Membranes in Biorefineries
- 2017
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Editorial proceedings (peer-reviewed)abstract
- The EMS Summer School “Membranes in Biorefineries” is related to Annex XVII of the Industrial Energy Related Technologies and Systems (IETS)Implementing Agreement: “Membrane Filtration for Energy-efficient Separation of Lignocellulosic Biomass Components” co-ordinated by the Department of Chemical Engineering at Lund University, Sweden.The IETS Implementing Agreement is an initiative within IEA (International Energy Agency). The mission of IETS is to foster international co-operation among OECD and non-OECD countries for accelerated research and technology development of industrial energy-related technologies and systems. In doing so, IETS seeks to enhance knowledge of cost-effective new industrial technologies and system layouts that enable increase productivity and better product quality while improving energy efficiency and sustainability.
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3rd International Conference on Material Engineering and Advanced Manufacturing Technology, 26–28 April 2019, Shanghai, China
- 2020
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Editorial proceedings (peer-reviewed)abstract
- We are very pleased to present the proceedings of the 3rd International Conference on Material Engineering and Advanced Manufacturing Technology (MEAMT 2019) that was held successfully under the auspices of IASED in Shanghai, China, April 26-28, 2019.The theme of the conference - Material Engineering and Advanced Manufacturing Technology - is of key importance to the science and technology and a sustainable industrial development. This conference promotes valuable contacts between academia and industry and addresses both basic research and the societal/industrial technological needs within Material Engineering and Advanced Manufacturing Technology.In this era of Industry 4.0, we hope that the conference provided applicable data/information, addressed the issues in the societal/industrial transformation, and facilitated exchange within and between academia and industry.We want to express our gratitude to the program chairs and all members of the advisory, publicity, and technical committees for their valuable time and advices. We are grateful to the world renowned scientists who acted as keynote speakers at the conference.After a rigorous review process, where each paper was reviewed by at least two reviewers, high quality papers were accepted for presentation at this conference. We would like to thank all the reviewers for their time, effort, and for completing their assignments on time albeit tight deadlines.Many thanks to the authors for their valuable contributions and to the attendees for their active participation.Finally, a big thank to the organizers who made this conference to yet another unforgettable experience.Nader AsnafiProfessor of Mechanical Engineering, Örebro University, Sweden Editor of the proceedings of MEAMT 2019 One behalf of the conference committee.
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7 koncept för bättre ergonomi
- 2016
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Editorial collection (pop. science, debate, etc.)abstract
- Fokus för ergonomi inom teknisk design är att se till att all design, oavsett vilket system det avser, kompletterar människans styrkor och förmågor. Vi ska kort och gott se till att arbetsuppgifter, utrustning, apparater, processer, miljöer och organisationer utformas med människan som utgångspunkt istället för att tvinga människan att anpassa sig med olika former av överbelastning som möjlig påföljd. För att uppnå det som kallas användarvänlighet behöver vi förstå och designa för den variation som vi människor representerar: vi är olika, vi har olika åldrar, storlek, styrka, kognitiv förmåga, tidigare erfarenheter, förväntningar och mål. Att tillämpa ergonomisk design betyder att studera hur människor interagerar med produkter, processer, miljöer och system för att förbättra dem, dvs. göra dem enklare, säkrare, bekvämare och effektivare att använda. För att kunna göra det behöver vi kunskap om människans förutsättningar och behov. Ergonomisk design kan exempelvis innebära: - Att designa produkter och utrustning som är enkla och tillförlitliga att använda med utgångspunkt i kunskap om kognitiv ergonomi, antropometri - och belastningsergonomiska analyser- Att designa säkra och effektiva tillverkningsprocesser med utgångspunkt i kunskap om kognitiv ergonomi och belastningsergonomiska analyser- Att designa organisationer utifrån kunskap om arbetslivsfysiologi och organisationsergonomi- Att designa arbetsuppgifter utifrån kunskap om kognitiv ergonomi, biomekanik och belastningsergonomiska analyserAtt designa enkla och användarvänliga gränssnitt med utgångspunkt i kognitiv ergonomiErgonomisk design av en produkt eller en arbetsmiljö kan exempelvis handla om att se till att produkten, systemet eller miljön inte bidrar till att människan använder kroppen på ett sätt som kan bidra till skador eller sjukskrivning. Det kan handla om att minimera fysisk belastning när en uppgift utförs eller att försäkra att den utförs på ett sätt som inte gör att skador uppstår. Det kan även handla om att se till att sensorisk input från olika system är utformad på ett sätt som upplevs som enkelt för användaren och därmed inte bidrar till mental belastning i form av stress. Det kan även handla om att designa organisationen eller hela produktionssystemet på ett sätt som utgår från användaren: människan i systemet. Med kunskaper om människans behov, preferenser, begränsningar, olikheter, erfarenheter och förmågor som utgångspunkt kan vi designa bättre lösningar. Det i sin tur bidrar till säkrare arbetsmiljöer, färre sjukskrivningar och användarvänligare produkter och system. Med mer kunskap kan vi uppnå att produkter, system och miljöer i vår omvärld fungera väl för människan – det är social och ekonomisk hållbar utveckling. Tvärvetenskap är ett begrepp som syftar på olika kunskaper, metoder och expertis från olika vetenskapsområden samverkar. Kursen Ergonomi II vid Luleå tekniska universitet är just tvärvetenskaplig, eftersom både innehåll och projekt i kursen omfattar kunskaper, metoder och tekniker från designvetenskap, hälsovetenskap och arbetsvetenskap. Lärarna i kursen var våren 2016 Daniel Öhrling som har förmedlat kunskap om design i allmänhet och prototypande som en designmetod i synnerhet, Agneta Larsson som har ansvarat för moment inom arbetslivsfysiologi, Ulrik Röijezon som ansvarat för momenten ergonomiska analyser och mätningar i rörelselabbet och Therese Öhrling som med stor kunskap och vilja att utveckla området ergonomisk design har ansvarat för ergonomi och arbetsvetenskap. I bokens första kapitel ges en inblick i belastningsergonomiska problem för målare. Måleriyrket omfattar många olika moment som ger belastning på handleder, rygg, axlar och nacke. I den inledande förstudien har Fanny Åkertröm och Hani Benjnouh fördjupat sig i målares vardag och därefter utvecklat två individuella koncept som syftar till att lösa de identifierade problemen. Lösningen blev två olika designkoncept som ska bidra till färre belastningsrelaterade sjukdomar. Den andra kontext som behandlas är frisöryrket. Frisörer arbetar ofta i arbetsställningar som kan bidra till belastningsergonomiska problem i nacke, rygg, axlar och handleder. Händerna befinner sig ofta i positioner som ger en hög belastning på kroppen. Gustaf Jörnelius, Linnea Stenman och Viktor Berglund har fördjupat sig i frisörers kontext och sedan utvecklat tre individuella designkoncept som kan bidra till bättre välmående för yrkesgrupppen. Joel Lantz och Christina Trång har tittat närmre på personer som arbetar med varuhantering. Denna yrkeskategori kan innebära belastningsergonomiska problem i och med lyft över huvudhöjd, sneda vinklingar i låga positioner och stäckningar i trånga lägen. Joel och Christina har sedan utvecklat två designkoncept som ska bidra till färre belastningsergonomiska skador.
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| 29. |
- A Asif, Farazee M, 1980-
(author)
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Circular Manufacturing Systems : A development framework with analysis methods and tools for implementation
- 2017
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Doctoral thesis (other academic/artistic)abstract
- The society today lives on the philosophy of ‘take-make-use-dispose.’ In the long run, this is not sustainable as the natural resources and the waste carrying capacity of the earth are limited. Therefore, it is essential to reduce dependency on the natural resources by decoupling the growth from the consumption. In this venture, both the society and the manufacturing industry have a vital role to play. The society needs to shift towards Circular Economy that rests upon the philosophy of ‘take-make-use-reuse’ and the manufacturing industry has to be a major stakeholder in this shift. Despite being proven to be both economically and environmentally beneficial, successful examples of circular systems are few today. This is primarily due to two reasons; firstly, there is a lack of systemic and systematic approach to guide industries and secondly, there is a lack of analysis methods and tools that are capable of assessing different aspects of circular manufacturing systems. Taking on to these challenges, the objective of this research is to bring forward a framework with methods and decision support tools that are essential to implement circular manufacturing systems. The initial conceptual framework with the systemic approach is developed based on extensive review and analysis of research, which is further adapted for industrial implementation. Systematic analysis methods, decision support and implementation tools are developed to facilitate this adaptation. This development has been supported by four cases from diverse manufacturing sectors. Behind each decision support tool, there are analysis methods built upon mainly system dynamics principles. These tools are based on simulation platforms called Stella and Anylogic. Among other things, these tools are capable of assessing the performance of closed-loop supply chains, consequences of resource scarcity, potential gains from resource conservation and overall economic and environmental performance of circular manufacturing systems.
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| 30. |
- A Asif, Farazee M, 1980-, et al.
(author)
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Performance analysis of the closed loop supply chain
- 2012
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In: Journal of Remanufacturing. - Germany : Springer Science and Business Media LLC. - 2210-4690. ; 2:4
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Journal article (peer-reviewed)abstract
- PurposeThe question of resource scarcity and emerging pressure of environmental legislations has brought a new challenge for the manufacturing industry. On the one hand, there is a huge population that demands a large quantity of commodities; on the other hand, these demands have to be met by minimum resources and pollution. Resource conservative manufacturing (ResCoM) is a proposed holistic concept to manage these challenges. The successful implementation of this concept requires cross functional collaboration among relevant fields, and among them, closed loop supply chain is an essential domain. The paper aims to highlight some misconceptions concerning the closed loop supply chain, to discuss different challenges, and in addition, to show how the proposed concept deals with those challenges through analysis of key performance indicators (KPI).MethodsThe work presented in this paper is mainly based on the literature review. The analysis of performance of the closed loop supply chain is done using system dynamics, and the Stella software has been used to do the simulation. Findings The results of the simulation depict that in ResCoM; the performance of the closed loop supply chain is much enhanced in terms of supply, demand, and other uncertainties involved. The results may particularly be interesting for industries involved in remanufacturing, researchers in the field of closed loop supply chain, and other relevant areas. Originality The paper presented a novel research concept called ResCoM which is supported by system dynamics models of the closed loop supply chain to demonstrate the behavior of KPI in the closed loop supply chain.
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| 31. |
- A. Bateki, Christian, et al.
(author)
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Of milk and mobiles: Assessing the potential of cellphone applications to reduce cattle milk yield gaps in Africa using a case study
- 2021
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In: Computers and Electronics in Agriculture. - : Elsevier BV. - 0168-1699. ; 191
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Journal article (peer-reviewed)abstract
- There are growing expectations that Information and Communication Technology (ICT) applications could help improve on-farm yields amongst smallholder farmers in developing countries, and consequently, food and nutrition security. However, few studies have quantified the actual contribution of ICT applications on farmers’ yields, and these studies predominantly focused on crop production. We assessed the potential of ICT applications to close milk yield gaps among small- and medium scale dairy cattle farmers in Africa. First, we developed a theoretical framework summarizing biophysical and socio-economic constraints that foster milk yield gaps and discussed which constraints can be addressed using ICT applications. Second, using a case study of a feeding advice application for dairy cattle pre-tested with farmers in rural Kenya, we analyzed how much stand-alone the application could contribute to close dairy cattle milk yield gaps. Our findings suggest that ICT applications could help address some existing biophysical and socio-economic constraints fostering milk yield gaps, including data collection for breeding programs, feeding management advice, and facilitating access to markets and capital. Our stand-alone ICT application closed yield gaps by 2 % to 6 % on representative farms. Several factors may explain the limited actual contribution of selected ICT applications to reduce existing milk yield gaps, including the quality of the input data and models used in ICT applications, and more structural constraints that cannot be addressed by digital tools. Therefore, although ICT applications could help address constraints to achieving higher milk yields on dairy farms, a significant contribution to improve yields may only be achieved when conditions surrounding their use are adequate.
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| 33. |
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A design of high performance gas sensor array withdiscrete islands of Au catalyst for increasing of ZnO nanowire junctions
- 2013
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Editorial proceedings (peer-reviewed)abstract
- In this study, an effective design for growth of ZnO nanowires directly on gas sensor chips is introduced. The design utilizes the dendrite islands of Au catalyst deposited between and on the Pt electrodes for the nanowires to grow on instead of a continuous seed layer or Au film. This lead to an increase of the nanowirenanowire junctions in the devices, as well as a reduction of the leak current that would occur through the mentioned alternative seed layer; resulting in a higher sensitivity. The results showed that the developed gas sensors could be used for monitoring of NO2 at low concentration.
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| 36. |
- A, Lavanya, et al.
(author)
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Smart energy monitoring and power quality performance based evaluation of 100-kW grid tied PV system
- 2023
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In: Heliyon. - 2405-8440. ; 9:6
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Journal article (peer-reviewed)abstract
- Globally, the demand for energy from renewable sources is growing due to the increasing electricity consumption and the pollution of fossil fuels. The government has framed various policies to facilitate green energy generation, encouraging renewable energy source usage through PV installations in multiple sectors, including educational institutions. The primary objective of this paper is to propose a methodological approach for analysing the performance of the installed PV system on the rooftop of a university building in Tamil Nadu, India. The site selected is favourable for electricity generation from PV systems with an average global solar radiation of 5.82 kWh/m2day. Solar energy changes periodically with annual and daily variations and is not steady due to seasonal changes. The step-by-step performance assessment and the annual performance of the 100-kW solar PV system, which was instituted in 2019, with the forecasted parameters, are presented in this paper. Therefore, the assessment analysis is carried out in four phases: feasibility assessment, Energy yield assessment, Life cycle assessment, and Power quality assessment. To improve the solar PV output and efficiency, considering the solar irradiation, temperature, wind velocity, etc., PV yield is measured to evaluate the PV system's energy metrics. This paper also considers the carbon credits earned, solar power generated in the location, and the payback period. The power quality assessment is carried out in this paper to test the PV plant's compliance with effective grid integration.
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| 37. |
- A. M. Naiini, Maziar, 1980-
(author)
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Horizontal Slot Waveguides for Silicon Photonics Back-End Integration
- 2014
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Doctoral thesis (other academic/artistic)abstract
- This thesis presents the development of integrated silicon photonic devices. These devices are compatible with the present and near future CMOS technology. High-khorizontal grating couplers and waveguides are proposed. This work consists of simulations and device design, as well as the layout for the fabrication process, device fabrication, process development, characterization instrument development and electro-optical characterizations.The work demonstrates an alternative solution to costly silicon-on-insulator photonics. The proposed solution uses bulk silicon wafers and thin film deposited waveguides. Back-end deposited horizontal slot grating couplers and waveguides are realized by multi-layers of amorphous silicon and high-k materials.The achievements of this work include: A theoretical study of fully etched slot grating couplers with Al2O3, HfO2 and AIN, an optical study of the high-k films with spectroscopic ellipsometry, an experimental demonstration of fully etched SiO2 single slot grating couplers and double slot Al2O3 grating couplers, a practical demonstration of horizontal double slot high-k waveguides, partially etched Al2O3 single slot grating couplers, a study of a scheme for integration of the double slot Al2O3 waveguides with selectively grown germanium PIN photodetectors, realization of test chips for the integrated germanium photodetectors, and study of integration with graphene photodetectors through embedding the graphene into a high-k slot layer.From an application point of view, these high-k slot waveguides add more functionality to the current silicon photonics. The presented devices can be used for low cost photonics applications. Also alternative optical materials can be used in the context of this photonics platform.With the robust design, the grating couplers result in improved yield and a more cost effective solution is realized for integration of the waveguides with the germanium and graphene photodetectors.
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| 38. |
- A Monfared, Behzad, 1983-
(author)
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Magnetic Refrigeration for Near Room-Temperature Applications
- 2018
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Doctoral thesis (other academic/artistic)abstract
- Refrigeration plays a crucial role in many different sectors and consumes about 17% of the electricity produced globally. This significant energy consumption implies large share of refrigeration in primary energy consumption and other environmental impacts. In addition to the environmental impacts associated with energy consumption, the vapor-compression systems contribute in global warming due to the release of their gaseous refrigerants into the atmosphere. As an alternative technology for near room-temperature applications, magnetic refrigeration is proposed by some researchers to eliminate the release of gaseous refrigerants into the atmosphere and to reduce the energy consumption. This thesis is a compilation of a number of studies done on magnetic refrigeration for room-temperature applications.In the first study, the environmental impacts associated to magnetic refrigeration are looked at closely through a life cycle assessment. The life cycle assessment indicates that because of the environmental burdens related to the rare-earth materials used in magnetic refrigeration, the reduction in the environmental impacts is not guaranteed by switching to magnetic refrigeration technology. Accordingly to avoid the extra environmental impacts the magnetic refrigeration systems should use magnetic materials frugally, which requires an optimized design. In addition, operation with higher efficiency compared to vapor-compression systems is necessary to have environmental advantages, at least in some impact categories.A practical method to optimize the design of magnetic refrigeration systems, e.g. to have a compact design or high efficiency, is utilizing a flexible software model, with which the effect of varying different parameters on the performance of the system can be simulated. Such a software model of the magnetic refrigeration system is developed and validated in this project. In developing the model one goal is to add to the precision of the simulated results by taking more details into consideration. This goal is achieved by an innovative way of modeling the parasitic heat transfer and including the effect of the presence of magnetocaloric materials on the strength of the field created by the magnet assembly. In addition, some efforts are made to modify or correct the existing correlations to include the effect of binding agents used in some active magnetic regenerators. Validation of the developed software model is done using the experimental results obtained from the prototype existing at the Department of Energy Technology, KTH Royal Institute of Technology.One of the parameters that can be modified by the developed software model is the choice of the magnetocaloric materials for each layer in a layered active magnetic regenerator. Utilizing the software model for optimizing the choice of the materials for the layers reveals that materials with critical temperatures equal to the cyclic average temperature of the layers in which they are used do not necessarily result in the desired optimum performance. In addition, for maximizing different outputs of the models, such as energy efficiency or temperature lift sustained at the two ends of the regenerators, different choice of materials for the layers are needed. Therefore, in other studies seeking to improve one of the outputs of a system, the choice of the transition or critical temperatures of the materials for each layer is an additional parameter to be optimized.The prototype existing at the Department of Energy Technology, KTH Royal Institute of Technology, was initially designed for replacing the vapor-compression system of a professional refrigerator. However, it could not fulfil the requirements for which it was initially designed. The aforementioned developed simulation model is used to see how much the choice of the materials, size of the particles, and number of layers can enhance the performance while the operation frequency and flow rate of the heat transfer fluid are at their optimum values. In other words, in that study the room for improvement in the performance without applying major changes in the system such as the geometry of the regenerator, which implies redesigning the whole magnet assembly, is investigated. In the redesign process the effect of binding agent and the limitations associated to different properties of it is also investigated theoretically. Nevertheless, the study did not show that with keeping the geometry of the regenerators and the currently existing magnetocaloric materials the initial goals of the prototype can be achieved.In the next study more flexible choice of geometries and magnetocaloric materials are considered. In fact, in this study it is investigated how much the magnetocaloric materials need to be improved so that magnetic refrigeration systems can compete with vapor-compression ones in terms of performance. For the two investigated cases, the magnetic-field dependent properties of the currently existing materials are enough provided that some other issues such as low mechanical stability and inhomogeneity of the properties are solved. Nevertheless, for more demanding design criteria, such as delivering large cooling capacity over a considerable temperature span while the magnetic materials are used sparingly, the magnetic-field dependent properties need to be enhanced, as well.A less explored area in room-temperature magnetic refrigeration is the subject of another study included in the thesis. In this study, solid-state magnetic refrigeration systems with Peltier elements as heat switches are modeled. Since the Peltier elements consume electricity to pump heat, the modeled systems can be considered hybrid magnetocaloric-Peltier cooling systems. For such systems the detailed transient behavior of the Peltier elements together with layers of magnetocaloric materials are modeled. The mathematical model is suitable for implementation in programing languages without the need for commercial modeling platforms. The parameters affecting the performance of the modeled system are numerous, and optimization of them requires a separate study. However, the preliminary attempts on optimizing the modeled system does not give promising results. Accordingly, focusing on passive heat switches can be more beneficial.
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| 39. |
- A. Mouris, Boules, et al.
(author)
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A Dual-Polarized Multi-Antenna Structure for Simultaneous Transmission of Wireless Information and Power
- 2019
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In: 2019 IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting, APSURSI 2019 - Proceedings. - : IEEE. ; , s. 1805-1806
-
Conference paper (peer-reviewed)abstract
- In this paper, a dual-polarized multi-antenna structure is designed at 2.45 GHz with the goal of allowing simultaneous transmission of wireless information and power. Differential feeding was used to minimize the mutual coupling due to radiation leakage in addition to a mushroom-type EBG structure for suppressing the surface waves. Simulation results for the proposed structure show a mutual coupling level lower than -40 dB between the information transmitting antenna and the power transmitting antennas for both polarizations. The isolation level between the antennas is improved by at least 22 dB and 14 dB for the E-plane and H-plane coupling, respectively.
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| 40. |
- A. Mouris, Boules, et al.
(author)
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Multi-tone Signal Optimization for Wireless Power Transfer in the Presence of Wireless Communication Links
- 2020
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In: IEEE Transactions on Wireless Communications. - : Institute of Electrical and Electronics Engineers (IEEE). - 1536-1276 .- 1558-2248. ; 19:5, s. 3575-3590
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Journal article (peer-reviewed)abstract
- In this paper, we study optimization of multi-tone signals for wireless power transfer (WPT) systems. We investigate different non-linear energy harvesting models. Two of them are adopted to optimize the multi-tone signal according to the channel state information available at the transmitter. We show that a second-order polynomial curve-fitting model can be utilized to optimize the multi-tone signal for any RF energy harvester design. We consider both single-antenna and multi-antenna WPT systems. In-band co-existing communication links are also considered in this work by imposing a constraint on the received power at the nearby information receiver to prevent its RF front end from saturation. We emphasize the importance of imposing such constraint by explaining how inter-modulation products, due to saturation, can cause high interference at the information receiver in the case of multi-tone signals. The multi-tone optimization problem is formulated as a non-convex linearly constrained quadratic program. Two globally optimal solution approaches using mixed-integer linear programming and finite branch-and-bound techniques are proposed to solve the problem. The achieved improvement resulting from applying both solution methods to the multi-tone optimization problem is highlighted through simulations and comparisons with other solutions existing in the literature.
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| 43. |
- A.S.M. Monjurul, Hasan, et al.
(author)
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Biogas potential from municipal and agricultural residual biomass for power generation in Hazaribagh, Bangladesh : A strategy to improve the energy system
- 2019
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In: Renewable Energy Focus. - : Elsevier BV. - 1755-0084. ; 29:June 2019, s. 14-23
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Journal article (peer-reviewed)abstract
- Energy is considered as one of the significant benchmarks towards sustainable growth. Due to the recenteconomic growth, energy demand is increasing day by day in Bangladesh. The power generation mainlyrelies on fossil fuels though there are plans to increase the renewable energy share by the concernstakeholders. Considering the global warming, energy generation from renewable sources is consideredas a sustainable way to mitigate the anthropogenic emission. This study, therefore, addresses thepotentiality of biogas production from municipal waste and agricultural residues in a city territory ofDhaka namely Hazaribagh. The potential sources include wastes from two markets, six slaughterhouses,domestic wastes, one poultry farm and three croplands. The calculations made in this study to estimatethe amount of biogas and electricity from the described sources are done in a simple way, just to illustratethe potential. This study suggests that there is a good potentiality of biogas production and electricitygeneration from municipal wastes and agricultural residues of Hazaribagh. Moreover, this study alsomentions the significant actors like government, future owners, people and so on that are needed to beincorporated to implement biogas solution in a city territory.
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| 44. |
- A:sson Utas, Jan, 1946-
(author)
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Ag, bräder och flis
- 1984
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In: Kulturminnesvård. - Stockholm : Riksantikvarieämbetet. - 0346-9077. ; :4, s. 12-15
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Journal article (pop. science, debate, etc.)
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| 45. |
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| 46. |
- A., Trubetskaya, et al.
(author)
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The Effect of Wood Composition and Supercritical CO2 Extraction on the Charcoal Production
- 2019
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In: 2019 AIChE Annual Meeting proceedings. - : American Institute of Chemical Engineers.
-
Conference paper (other academic/artistic)abstract
- This work demonstrated that the coupling of supercritical carbon dioxide extraction with slow pyrolysis is effective to remove over half of extractives from low quality wood and to generate biochar from remaining solid wood fractions. The high yields of extractives from supercritical carbon dioxide extraction illustrates the potential utilizing of low quality wood as an alternative feedstock for the sustainable production of value-added chemicals. Results showed that supercritical carbon dioxide extraction has neither a strong impact on the physical properties of original wood nor on the yield of solid biochar. These results are promising as they show that the biochar obtained for this renewable feedstock could be used as an alternative to fossil-based coke in applications including ferroalloy industries. Moreover, the heat treatment temperature and supercritical carbon dioxide extraction had a significant impact on the tar yields, leading to the increase in naphthalene, polycyclic aromatic hydrocarbons, aromatic and phenolic fractions with the greater temperature. The differences in gasification reactivity and dielectric properties of solid biochars, composition and yields of liquid products of non-treated pinewood and extracted wood fraction emphasize the impact of supercritical carbon dioxide extraction on the pyrolysis process.
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| 47. |
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| 48. |
- A.V., Fidalgo, et al.
(author)
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Adapting remote labs to learning scenarios : Case studies using VISIR and remotElectLab
- 2014
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In: Revista Iberoamericana de Tecnologias del Aprendizaje. - : Education Society of IEEE (Spanish Chapter). - 1932-8540. ; 9:1, s. 33-39
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Journal article (peer-reviewed)abstract
- Remote laboratories are an emergent technological and pedagogical tool at all education levels, and their widespread use is an important part of their own improvement and evolution. This paper describes several issues encountered on laboratorial classes, on higher education courses, when using remote laboratories based on PXI systems, either using the VISIR system or an alternate in-house solution. Three main issues are presented and explained, all reported by teachers, that gave support to students' use of remote laboratories. The first issue deals with the need to allow students to select the actual place where an ammeter is to be inserted on electric circuits, even incorrectly, therefore emulating real-world difficulties. The second one deals with problems with timing when several measurements are required at short intervals, as in the discharge cycle of a capacitor. In addition, the last issue deals with the use of a multimeter in dc mode when reading ac values, a use that collides with the lab settings. All scenarios are presented and discussed, including the solution found for each case. The conclusion derived from the described work is that the remote laboratories area is an expanding field, where practical use leads to improvement and evolution of the available solutions, requiring a strict cooperation and information-sharing between all actors, i.e., developers, teachers, and students.
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| 49. |
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A wideband frequency selective surface reflector for 4G/X-Band/Ku-Band
- 2018
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In: Progress In Electromagnetics Research C. - : Electromagnetics Academy. - 1937-8718. ; 81, s. 151-159
-
Journal article (peer-reviewed)abstract
- A Frequency Selective Surface (FSS) reflector with wideband response for 4G/X-band/Ku-band is proposed. The wideband FSS reflector consists of cascaded dual-layer patch FSS which is etched on separate layers of FR4 substrate. The targeted frequency range is 5–16 GHz. A wide stopband of 10.4 GHz (100% percent bandwidth) is obtained with two layers in cascade. The Equivalent Circuit (EC) method is used to approximate the simulated results. An extensive parametric study is also carried out to understand the effect of various combinations of FSS layers and their disposition. A panel of final FSS is fabricated where measured and simulated results agree well.
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| 50. |
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