Recent additions

  • Non-parametric Linear Technique for Measuring the Efficiency of Winter Road Maintenance in the Arctic Area 

    Hatamzad, Mahshid; Polanco Pinerez, Geanette (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-10-05)
    Improving the performance of Winter Road Maintenance (WRM) can increase the traffic safety and reduce the cost as well as environmental impacts. This study evaluates the efficiency of WRM technique, named salting, in the Arctic area by using Data Envelopment Analysis (DEA), which is a non-parametric linear method to measure the efficiencies of decision-making units (DMUs) based on handling multiple ...
  • Multidimensional Hardy-type inequalities on time scales with variable exponents 

    Fabelurin, Olanrewaju O; Oguntuase, J. A.; Persson, Lars Erik (Journal article; Peer reviewed, 2019)
    A new Jensen inequality for multivariate superquadratic functions is derived and proved. The derived Jensen inequality is then employed to obtain the general Hardy-type integral inequality for superquadratic and subquadratic functions of several variables.
  • Ventilation and environmental control of underground spaces: A short review 

    Li, Angui; Kosonen, Risto; Melikov, Arsen; Yang, Bin; Olofsson, Thomas; Sørensen, Bjørn Reidar; Zhang, Linhua; Cui, Ping; Han, Ou (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-08-13)
    More and more underground spaces were used in 21st century because of rapid urbanization, traffic problems, etc. Underground city, metro, tunnel, mine, industrial and agriculture engineering, civil air defence engineering need large underground spaces. Underground spaces with different thermal, ventilation and lighting environments may cause comfort, health and safety problems. Concrete problems ...
  • Optimization of the CO2 Liquefaction Process-Performance Study with Varying Ambient Temperature 

    Jackson, Steven; Brodal, Eivind (Journal article; Peer reviewed, 2019-10-22)
    In carbon capture utilization and storage (CCUS) projects, the transportation of CO2 by ship can be an attractive alternative to transportation using a pipeline, particularly when the distance between the source and usage or storage location is large. However, a challenge associated with this approach is that the energy consumption of the liquefaction process can be significant, which makes the ...
  • Multiphysics study of infrared thermography (IRT) applications 

    Andleeb, Zahra; Ilyas, Muhammad; Khawaja, Hassan; Moatamedi, Mojtaba (Conference object; Konferansebidrag, 2019-12)
    Infrared thermography is the science of detecting infrared energy emitted from an object, converting it to apparent temperature, and producing images of that radiation, called thermograms. Infrared thermography means "beyond red temperature image". IR thermography being a remote non-contact/non-destructive means of testing is perfectly suitable for tests in extreme environments. Also, it is fast, ...
  • Best Venue to Disseminate Multiphysics Research 

    Khawaja, Hassan (Conference object; Konferansebidrag, 2019-12)
    Multiphysics analysis has been developed over the recent past to better represent the behaviour of complex processes by the use of simultaneous modelling of a number of systems. This development is driven by the industrial need to further the understanding of real physical phenomena in order to develop and design safer and more efficient products which are environmentally friendly. Such analyses ...
  • The International Conference of MULTIPHYSICS 2020 

    Khawaja, Hassan (Conference object; Konferansebidrag, 2019-12)
    Multiphysics analysis has become increasingly important in recent years due to demand in design and understanding of complex systems. The objective of the conferences is to share and explore findings on mathematical advances, numerical modelling and experimental validation of theoretical and practical systems in a wide range of applications.
  • The FlexNett Simulator 

    Bremdal, Bernt Arild; Tangrand, Kristoffer (Journal article; Peer reviewed, 2019)
    This paper documents research conducted in the Norwegian FLEXNETT project.<br>It describes a new tool that was developed to study the future impact of prosumers with PV panels on the grid in Norway and the potential energy flexibility that lies with residential prosumers. Systematic use of energy flexibility can be an important instrument for managing peak loads and voltage problems in weak power ...
  • Local energy markets as a solution for increased energy efficiency and flexibility 

    Ilieva, Iliana; Bremdal, Bernt Arild; de la Nieta Lopez, A.A.S.; Simonsen, S.H. (Journal article; Peer reviewed, 2019)
    With increasing share of distributed renewable energy resources in the grid and arising energy consumer awareness on environmental challenges new market models are sought where energy can be traded in an efficient and end-user centric way. This trend, together with the increasing consciousness on the benefits of local consumption and production has given rise to an increased focus on local energy ...
  • Towards a Framework for Noctilucent Cloud Analysis 

    Sharma, Puneet; Dalin, Peter; Mann, Ingrid (Journal article; Tidsskriftartikkel; Peer reviewed, 2019)
    In this paper, we present a framework to study the spatial structure of noctilucent clouds formed by ice particles in the upper atmosphere at mid and high latitudes during summer. We studied noctilucent cloud activity in optical images taken from three different locations and under different atmospheric conditions. In order to identify and distinguish noctilucent cloud activity from other objects ...
  • IR Thermography of Steel Specimens undergoing Tensile Tests 

    Stange, Even; Khawaja, Hassan (Conference object, 2018-12-13)
    In this work, the IR thermography was used to study the steel specimens (DIN 50125 Standard) undergoing the tensile tests. The tensile tests were performed using GUNT® Hamburg Universal Material Tester. The tensile specimens were clamped, and the test force was generated using a hand-operated hydraulic system. A dial gauge measured the elongation of the specimens. Using the WP 300.20 system for data ...
  • Surface Functionalization of Carbon Nanotubes for Energy Applications 

    Berber, Mohamaed; Hafez, Inas H.; Mustafa, Mohamad Y. (Peer reviewed; Chapter, 2018-05-05)
    Carbon nanotubes (CNTs) are receiving a great deal of attention as a catalyst support for different energy applications, due to their high surface area and high conductivity. Recent literature studies have shown that the application of CNTs mainly depends on their surface functionalization process. Typically, pristine CNTs (as produced) have no functional groups, which is usually considered as an ...
  • Droplet distribution spectrum effects on dry ice growth on cylinders 

    Sokolov, Pavlo; Virk, Muhammad (Journal article; Peer reviewed, 2019-01-06)
    A detailed parametric analytical study along with a series of viscid multiphase numerical simulations of ice accretion were performed in comparison with experimental data of ice accretion on a 30 mm diameter cylinder. The study was performed for droplet distribution spectra, Langmuir (A-J), in addition to an experimental droplet distribution obtained in an icing tunnel.<br>Analysis shows that droplet ...
  • Interpreting teaching for conceptual and for procedural knowledge in a teaching video about linear algebra 

    Rensaa, Ragnhild Johanne; Vos, Pauline (Journal article; Tidsskriftartikkel, 2018)
    The aim of this study is to investigate teaching videos about mathematics, seeking to uncover research-based foundations for their quality. By drawing on the notions of procedural and conceptual knowledge, the research was operationalized by asking professionals in undergraduate mathematics education (n=18) to interpret sections of a teaching video. The video dealt with a topic in linear algebra. ...
  • A comparative study of CO2 heat pump performance for combined space and hot water heating 

    Brodal, Eivind; Jackson, Steven (Journal article; Peer reviewed, 2019-08-20)
    Heat pumps used for combined space and hot water heating are often used in modern energy-efficient buildings. Performance depends on both system design (exchanger sizes, compressor efficiency, etc.) and operating conditions (inlet water temperature, ratio between space and water heating, etc.). Designs using both CO2 and HFCs, such as R410A, are available, but the relative performance of these is ...
  • Performance and Design Study of Optimized LNG Mixed Fluid Cascade Processes 

    Brodal, Eivind; Jackson, Steven; Eiksund, Oddmar (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-09-26)
    Mixed Fluid Cascade (MFC) processes are often claimed to be one of the most efficient methods to liquefy natural gas. Their performance depends on both operating conditions such as ambient temperature, and system design parameters such as exchanger sizes. The performance of the standard MFC process can be further improved by modifying the design with additional equipment, such as liquid refrigerant ...
  • Multiphysics Impact Analysis of Carbon Fiber Reinforced Polymer (CFRP) Shell 

    Strand, Cathrine Høgmo; Andleeb, Zahra; Khawaja, Hassan; Moatamedi, Mojtaba (Journal article; Peer reviewed, 2019-07-30)
    With increasing popularity of Carbon Fiber Reinforced Polymer (CFRP) over time, the need for research in the field has increased dramatically. Many industries, i.e. aeronautical, automotive, and marine are opting to install carbon fiber in their structures to account for harsh environments like cold temperatures applications, but the research on the temperature exposure behavior of the materials are ...
  • Digitalized manufacturing logistics in engineer-to-order operations 

    Strandhagen, Jo Wessel; Buer, Sven-Vegard; Semini, Marco; Alfnes, Erlend (Chapter; Bokkapittel, 2019)
    The high complexity in Engineer-To-Order (ETO) operations causes major challenges for manufacturing logistics, especially in complex ETO, i.e. one-of-a-kind production. Increased digitalization of manufacturing logistics processes and activities can facilitate more efficient coordination of the material and information flows for manufacturing operations in general. However, it is not clear how to ...
  • Some Fourier inequalities for orthogonal systems in Lorentz–Zygmund spaces 

    Akishev, Gabdolla; Persson, Lars Erik; Seger, Andreas (Journal article; Peer reviewed, 2019-06-13)
    A number of classical inequalities and convergence results related to Fourier coefficients with respect to unbounded orthogonal systems are generalized and complemented. All results are given in the case of Lorentz–Zygmund spaces.
  • Effekt av basaltfiber for betongkvalitet = Effect of basalt fiber for quality of concrete 

    Ha, Duy Quang (Master thesis; Mastergradsoppgave, 2019-06-27)
    The need of concrete is getting more and more, experts have researched new materials to improve the good properties of concrete. Basalt fiber is a new additive in the concrete industry, so researches on basalt fiber concrete is not many. Previous research results have shown positive effects of basalt fiber on the mechanical strengths of the concrete. This task is performed by experiments to confirm ...

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