Viser treff 41-60 av 67

    • Modelling Multi-layer Hydronic Radiators 

      Chen, Liguo; Sørensen, Bjørn Reidar (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-06-30)
      This report simulates Purmo type C22 and C33 radiators with both standard calculation and heat transfer method with help of Matlab/Simulink. Simulation results are presented to describe the radiators’ thermal performances with different simulation strategies. The deviations between two different calculation methods are identified and the heat transfer radiator model can be improved with more ...
    • Green Building in the Arctic Region: State-of-the-Art and Future Research Opportunities 

      Ravasio, Lucrezia; Sveen, Svein-Erik; Riise, Raymond (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-11-10)
      The concept of Green Building refers to environmentally friendly constructions with the target of minimizing the impact on the natural environment through sustainable and efficient use of resources over their life cycle. Since modern buildings are large contributors to global energy consumption and greenhouse gas emissions, policies and international strategies intended to reduce the carbon footprint ...
    • Green Buildings in the Arctic region: a literature review 

      Ravasio, Lucrezia; Riise, Raymond; Sveen, Svein-Erik (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-06-30)
      Green Buildings are defined as environmental-friendly buildings aimed at minimizing the impact on the natural environment through a sustainable and efficient use of resources over their life-cycle. This is, perhaps, a recently-introduced building concept that is increasingly gaining attention due to the policies and strategies intended to reduce the carbon footprint of conventional buildings, which ...
    • Ship resistance analysis using CFD simulations in Flow-3D 

      Deshpande, Sujay; Sundsbø, Per-Arne; Das, Subhashis (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-09-19)
      While designing the power requirements of a ship, the most important factor to be considered is the ship resistance, or the sea drag forces acting on the ship. It is important to have an estimate of the ship resistance while designing the propulsion system since the power required to overcome the sea drag forces contribute to ‘losses’ in the propulsion system. There are three main methods to calculate ...
    • Parametric Sensitivity of CSTBRs for Lactobacillus casei: Normalized Sensitivity Analysis 

      Das, Subhashis; Calay, Rajnish K; Chowdhury, Ranjana (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-06-18)
      In this paper, a sensitivity analysis of a continuous stirred tank bioreactor (CSTBR) was conducted to determine a parametrically sensitive regime. The growth of a lactic acid bacterium, namely, <i>Lactobacillus casei</i>, in a pH-controlled CSTBR was considered as a process model. Normalized objective sensitivities of the minimum pH were determined with respect to input parameters. A generalized ...
    • Product Inhibition of Biological Hydrogen Production in Batch Reactors 

      Das, Subhashis; Calay, Rajnish K; Chowdhury, Ranjana; Nath, kaustav; Eregno, Fasil (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-03-12)
      In this paper, the inhibitory effects of added hydrogen in reactor headspace on fermentative hydrogen production from acidogenesis of glucose by a bacterium, Clostridium acetobutylicum, was investigated experimentally in a batch reactor. It was observed that hydrogen itself became an acute inhibitor of hydrogen production if it accumulated excessively in the reactor headspace. A mathematical model ...
    • Construction professionals’ perspectives on drivers and barriers of sustainable construction 

      Tokbolat, Serik; Karaca, Ferhat; Durdyev, Serdar; Calay, Rajnish K (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-06-05)
      With the associated environmental challenges and unsustainable patterns of construction, there is also notable awareness and willingness among the state bodies to adopt sustainability measures and practices in Kazakhstan. This study explores the drivers of and barriers inhibiting the adoption of sustainability paradigm in the construction context of Kazakhstan. The drivers and barriers were validated ...
    • Numerical study on the ventilation performance of a livestock house built in porous panels in Cold Regions 

      Mustafa, Mohamad; Xu, Yizhong; Calay, Rajnish K; Sørensen, Bjørn Reidar (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-11)
      This paper presents a numerical prediction on the assessment of natural ventilation on a livestock house built in porous panels, aided by Computational Fluid Dynamics techniques. A typical climatic environment in Cold Regions was taken into consideration. The ventilation performances have been assessed by the distribution of indoor air velocity, turbulence intensity and local mean age of air through ...
    • Numerical study on the ventilation performance of a livestock house built in porous panels in Cold Regions 

      Xu, Yizhong; Mustafa, Mohamad; Calay, Rajnish K; Sørensen, Bjørn Reidar (Journal article; Tidsskriftartikkel; Peer reviewed, 2019)
      This paper presents a numerical prediction on the assessment of natural ventilation on a livestock house built in porous panels, aided by Computational Fluid Dynamics techniques. A typical climatic environment in Cold Regions was taken into consideration. The ventilation performances have been assessed by the distribution of indoor air velocity, turbulence intensity and local mean age of air through ...
    • Feasibility study for utilization of solar energy in the arctic areas 

      Tamrakar, Stutee; Mustafa, Mohamad; Riise, Raymond (Journal article; Tidsskriftartikkel; Peer reviewed, 2019)
      This research investigates a solar thermal system and a solar photovoltaic system which produces local energy, by incoming solar radiation, to meet the energy consumption demand of a residential building in the arctic region. The study on the use of the solar systems in the arctic areas is rare and often doubted. So, to analyze the potential of solar energy, a study case of an existing building block ...
    • 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 ...
    • 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 ...
    • Control of Airborne Noise Generated in the Cavities of a T-Slotted Aluminum Cylindrical Column 

      Mustafa, Mohamad Y.; Yizhong, Xu; Sørensen, Bjørn Reidar; Santos, José; Al-Mahadin, Aziz (Peer reviewed; Chapter, 2018-06-11)
      This paper presents a study of airborne noise generated by a T-slotted cylindrical aluminum hollow column with six slots of the type used for the construction of communication towers. Noise is a very distracting phenomena and an environmental concern caused by various sources. Noise pollution is becoming more severe with the introduction of massive human activities and the use of heavy machineries, ...
    • Fuel cell technology application for Dubai rail systems 

      Mustafa, Mohamad; Al-Mahadin, Aziz; Kanstad, Bjørn Eirik; Calay, Rajnish K (Peer reviewed; Chapter, 2018-06-11)
      Heat engines, such as internal combustion engines, have significant adverse effects on the environment due to their heat and harmful emissions. In addition, they are dependent on energy from fossil resources, which are depleting rapidly and they are not being properly utilized due to the relatively low efficiency of heat engines usually expressed by Carnot's efficiency. The low temperature direct ...
    • Utilizing fuel cell technology for Dubai Roads and Transport Authority (RTA) 

      Al-Mahadin, Aziz; Mustafa, Mohamad (Peer reviewed; Chapter, 2018-06-11)
      The need for developing environmentally friendly and sustainable energy sources is globally evident. This is due to two main reasons: Fossil fuels will continue to supply energy demands for only a few more decades and the amount of pollution generated due to fossil fuels is exceeding acceptable limits. One very promising clean energy converter is the fuel cell (FC). Fuel cells have the ability to ...
    • Feasibility of Computational Fluid Dynamics for Analyzing Airflow around Porous Fences 

      Xu, Yizhong; Calay, Rajnish K; Mustafa, Mohamad (Journal article; Peer reviewed, 2019-01-19)
      This article presents using the computational fluid dynamics (CFD) modeling to analyze the flow around porous fences. The feasibility of applying 2D and 3D models was assessed with respect to corresponding wind tunnel experiments. Comparisons between the flow structures on leeward of the fence as predicted by CFD models and the wind tunnel measurements were discussed. Velocity values for the two ...
    • A Hybrid Biomass Hydrothermal Gasification- Solid Oxide Fuel Cell System Combined with Improved CHP Plant for Sustainable Power Generation 

      Mustafa, Mahmoud; Nord, Natasa; Calay, Rajnish K; Mustafa, Mohamad (Journal article; Peer reviewed; Tidsskriftartikkel, 2017)
      The most popular technique, so far, for biomass waste to energy conversion has been incineration, but this technique has raised a lot of objection among nature activists due to the release of particulate matter and pollutants like nitrogen oxides (NOx) into the atmosphere. However, advanced non-incineration conversion methods like pyrolysis, thermal gasification, and plasma-arc gasification are ...
    • Numerical Simulation of Non-normal Wind Load on Porous Fences 

      Xu, Yizhong; Mustafa, Mohamad; Calay, Rajnish K; Sørensen, Bjørn Reidar (Journal article; Peer reviewed; Tidsskriftartikkel, 2017)
      This paper presents a numerical simulation of non-normal wind loads on a porous fence. It was found that non-normal wind load has significant impact on the performance of the fence in terms. The performance of the fence was measured as the effective fence zone behind the fence where flow characteristics and normal drag coefficients were maintained within safe level. It is recommended the incidental ...
    • Efficient Distributed Localization Algorithm for Ownership Identification of Reindeer Calf Using Wireless Sensor Networks 

      Mustafa, Mohamad; Morral Adell, Gemma; diengy, Ndeye Amy (Journal article; Tidsskriftartikkel, 2017)
      This paper presents a distributed algorithm for identifying the ownership of new-born reindeer calves using wireless sensor networks (WSNs). Reindeer are semi wild animals giving birth while in the wild. Although reindeer cows usually carry identification tags or signs of their owners, it is difficult to identify the ownership of the calves within a mixed herd. Currently, identification is performed ...
    • A Techno-economic Study of a Biomass Gasification Plant for the Production of Transport Biofuel for Small Communities 

      Mustafa, Albara Mohamad Yazid Faisal; Calay, Rajnish K; Mustafa, Mohamad (Journal article; Peer reviewed; Tidsskriftartikkel, 2017-03-30)
      A techno-economic feasibility study of liquid bio-fuel production from biomass to meet the demand for public transport in small communities is presented. The methodology adopted in this work is based on calculating the demand of fuels required by transport sector and then estimating the amount of available biomass from various sources which can be treated to produce biofuels to meet the demand ...