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5,648 full-text articles. Page 41 of 124.

The Performance Response Of A Heat Pipe Evacuated Tube Solar Collector Using Mgo/Mwcnt Hybrid Nanofluid As A Working Fluid, Ahmed A. Abdel-Rehim, shady Henein 2022 The British University in Egypt

The Performance Response Of A Heat Pipe Evacuated Tube Solar Collector Using Mgo/Mwcnt Hybrid Nanofluid As A Working Fluid, Ahmed A. Abdel-Rehim, Shady Henein

Mechanical Engineering

Utilizing a hybrid nanofluid is a promising solution for enhancing the thermal performance of the solar collector in a sustainable manner. In the present work, the effect of using magnesium oxide/multi-walled carbon nanotubes (MgO/MWCNT) hybrid nanofluid on the thermal performance of the evacuated tube solar collector is experimentally investigated. Four different weight ratios of (80:20), (70:30), (60:40), and (50:50) are used for a hybrid of MgO with MWCNTs in a water base, respectively. The experiments are performed at a 0.02% particle concentration and at various volume flow rates ranging from 1 to 3 L/min. The results show an enhancement in …


Tidal Current Turbine Blade Optimisation With Improved Blade Element Momentum Theory And A Non-Dominated Sorting Genetic Algorithm, Eng Jet Yeo, David Kennedy, Fergal O'Rourke 2022 Dundalk Institute of Technology

Tidal Current Turbine Blade Optimisation With Improved Blade Element Momentum Theory And A Non-Dominated Sorting Genetic Algorithm, Eng Jet Yeo, David Kennedy, Fergal O'Rourke

Articles

Tidal current energy has the advantage of predictability over most of the other renewable energy resources. However, due to the harsh operating environment and complicated site conditions, developments in this domain have been gradual. Paramount to these points is device design and optimisation of hydrodynamic performance. Recent developments in the correction models of BEM theory have further improved the accuracy of the prediction model. Using an improved blade element momentum theory model that is capable of accurately capturing the downwash angle and combining it with a well-developed and reliable non-dominated sorting genetic algorithm model, an effective and efficient tidal current …


Building Performance - Societal Drive, Programme And Symposium, Joseph Little, Patrick Daly 2022 Technological University Dublin

Building Performance - Societal Drive, Programme And Symposium, Joseph Little, Patrick Daly

Articles

Society is increasingly looking at the construction industry to mitigate the environmental crisis and solve the housing crisis through wholesale embrace of three broad sets of challenges. The MSc in Building Performance (Energy Efficiency in Design) (MSc BP(EED)) was created in 2017 to provide significant upskilling in the knowledge, skills, and software applications of building design professionals so that they can meet these challenges, while creating compliant, sustainable, super-low energy, new and renovated buildings. The delivery of the programme supports upskilling of employed building design professionals at Masters level, encouraging a minority to develop their capacity and interest in research …


Analysis Of Bio-Alcohols With Mie-Scattering And Ltc For Lowered Emissions In Pcci, Cesar E. Carapia 2022 Georgia Southern University

Analysis Of Bio-Alcohols With Mie-Scattering And Ltc For Lowered Emissions In Pcci, Cesar E. Carapia

College of Graduate Studies: Theses & Dissertations

An investigation was conducted on the optimal engine parameters for facilitating lower NOX and soot emissions of PCCI combustion with either ethanol or n-butanol. The PFI fuels selected were tested at loads of 3, 4, and 5 Bar IMEP for a total of 28 total combustion tests with variations made to the EGR% and boost pressure for each test in order to find the optimal emissions strategy. A Mie-scattering spray fuel analysis was also conducted on the three fuels to gain insight on their influence on combustion/emissions characteristics. It was found that ethanol had a greater average Sauter Mean Diameter …


An Innovative Elastohydrodynamic Seal Concept For Gases, Matthew J. DeMond 2022 Georgia Southern University

An Innovative Elastohydrodynamic Seal Concept For Gases, Matthew J. Demond

College of Graduate Studies: Theses & Dissertations

Supercritical CO2 (sCO2) power cycles are next generation power technologies offering improved efficiency, lower customer costs, and less water usage. They hold significant potential in many different industries such as nuclear power production, ship propulsion, geothermal power, solar power, and fossil fuel power plants. One of the largest hurdles preventing this milestone is the lack of suitable shaft seals for sCO2 operating conditions. This component issue needs to be addressed for the next generation nuclear turbine and compressor development to progress. In this study, a novel Elastohydrodynamic (EHD) seal is proposed. This proposed design is capable …


Cfd And Heat Transfer Analysis Of Rocket Cooling Techniques On An Aerospike Nozzle, Geoffrey Sullivan 2022 Georgia Southern University

Cfd And Heat Transfer Analysis Of Rocket Cooling Techniques On An Aerospike Nozzle, Geoffrey Sullivan

College of Graduate Studies: Theses & Dissertations

In recent years the development of rocket engines has been mainly focused on improving the engine cycle and creating new fuels. Rocket nozzle design has not been changed since the late 1960s. Recent needs for reliable and reusable rockets, as well as advancements in additive manufacturing, have brought new interest into the aerospike nozzle concept. This nozzle is a type of altitude adjusting nozzle that is up to 90% more efficient than bell nozzles at low altitudes and spends up to 30% less fuel. Since the nozzle body is submerged in the hot exhaust gasses it is difficult to keep …


Responses Of An Axially Rotated Tube Versus Twisted Tube Design As Two Solutions To Enhance The Thermal Performance Under A Non-Uniform Heat Flux Condition: A Numerical Study, Andrew S. Tanious, Ahmed A. Abdel-Rehim, Ahmed A. Attia 2022 The British University in Egypt

Responses Of An Axially Rotated Tube Versus Twisted Tube Design As Two Solutions To Enhance The Thermal Performance Under A Non-Uniform Heat Flux Condition: A Numerical Study, Andrew S. Tanious, Ahmed A. Abdel-Rehim, Ahmed A. Attia

Mechanical Engineering

Enhancement of heat transfer in tubes exposed to non-uniform heat flux applications is a key factor in increasing such applications' efficiency.

In the present study, heat transfer in an axially rotating pipe with concentrated heat flux at the lower section of the pipe is numerically investigated and compared to the twisting technique in such applications. The effects of pipe’s length (1, 2, and 3 m) and rotation rate (N = 0–10.5), which is the ratio between the rotational and axial Reynold’s numbers, are studied numerically using ANSYS Fluent while the effect of the twist ratio (S = 0.1–1m) is studied …


Process Optimization For An Integrated Reverse Osmosis—Pressure Retarded Osmosis Pilot-Scale System Operated On Humboldt Bay, Ca, Galen O'Toole 2022 Humboldt State University

Process Optimization For An Integrated Reverse Osmosis—Pressure Retarded Osmosis Pilot-Scale System Operated On Humboldt Bay, Ca, Galen O'Toole

Cal Poly Humboldt theses and projects

Pressure retarded osmosis (PRO) is an emerging osmotic power technology that could mitigate the major challenges faced by seawater reverse osmosis desalination (RO): brine disposal and high energy consumption. The primary focus of this paper is process optimization for a linked seawater reverse osmosis (RO) and pressure retarded osmosis (PRO) water purification system. PRO generates power by using osmosis to “pump” water through a membrane from low pressure and low concentration to high pressure and high concentration (RO brine). This commercial-scale pilot effort explores process optimization for pressure retarded osmosis as an industrial process rather than theoretical or experimental process. …


Combustion Feature Characterization Using Computer Vision Diagnostics Within Rotating Detonation Combustors, Kristyn B. Johnson May 2022 West Virginia University

Combustion Feature Characterization Using Computer Vision Diagnostics Within Rotating Detonation Combustors, Kristyn B. Johnson May

Graduate Theses, Dissertations, and Problem Reports (ETD)

In recent years, the possibilities of higher thermodynamic efficiency and power output have led to increasing interest in the field of pressure gain combustion (PGC). Currently, a majority of PGC research is concerned with rotating detonation engines (RDEs), devices which may theoretically achieve pressure gain across the combustor. Within the RDE, detonation waves propagate continuously around a cylindrical annulus, consuming fresh fuel mixtures supplied from the base of the RDE annulus. Through constant-volume heat addition, pressure gain combustion devices theoretically achieve lower entropy generation compared to Brayton cycle combustors. RDEs are being studied for future implementation in gas turbines, where …


Coastal Wave Powered Reverse Osmosis System, Alexander Raymond Charest, Joeseph Daniel Camobreco, Tori Sweet, Sam Williams, Andrew LePage, Devan Sack, Meagan Wiggin, Chelsea Kimball, Brendan Reagan 2022 University of New Hampshire

Coastal Wave Powered Reverse Osmosis System, Alexander Raymond Charest, Joeseph Daniel Camobreco, Tori Sweet, Sam Williams, Andrew Lepage, Devan Sack, Meagan Wiggin, Chelsea Kimball, Brendan Reagan

Honors Theses and Capstones

Part of the Marine Energy Collegiate Competition (MECC) is the optional Build and Test Challenge where teams are encouraged to build a portion of their proposed solution. After the conducted testing the laboratory results are compared to the simulated and calculated models. For the MECC the University of New Hampshire (UNH) team decided to use a wave energy converter to produce pressurized water. The pressurized water would be filtered through a reverse osmosis membrane to make it potable. Our system uses the power of the ocean waves to move a float up and down in heave motion. This motion drives …


Empirical Comparison Of Machine Learning Methods For Wind Power Predictions, Sidny M. Stewart 2022 Eastern Washington University

Empirical Comparison Of Machine Learning Methods For Wind Power Predictions, Sidny M. Stewart

EWU Masters Thesis Collection

No abstract provided.


Controlling The Thermal And Electrical Properties Of Camno3-Δ Based Perovskite Ceramics, Sergio Andres Paredes Navia 2022 West Virginia University

Controlling The Thermal And Electrical Properties Of Camno3-Δ Based Perovskite Ceramics, Sergio Andres Paredes Navia

Graduate Theses, Dissertations, and Problem Reports (ETD)

Most of the energy lost during the conversion process comes in the form of waste heat. The world's energy consumption loses over 60% of its energy after conversion. In order to increase the efficiency of the conversion process, it is essential to harness waste heat and reutilize this energy resource. Heat recovery technology as thermoelectric (TE) technology is one of the growing alternatives to harvest excessive amounts of energy lost as waste heat for a more efficient, safe, and sustainable future. Due to the Seebeck effect, TE materials have the potential to convert waste heat directly into electricity, improving efficiency …


Analysis Of Emissions Profiles Of Hydraulic Fracturing Engine Technologies, Nicholas Joseph Wells 2022 West Virginia University

Analysis Of Emissions Profiles Of Hydraulic Fracturing Engine Technologies, Nicholas Joseph Wells

Graduate Theses, Dissertations, and Problem Reports (ETD)

In the past twenty years natural gas production in the United States has significantly increased. This is largely due to technological advancements in unconventional methods of horizontal drilling and hydraulic fracturing. With these new and improved technologies, the United States has been able to increase its natural gas dry production per year by 14.5 trillion cubic feet per year from 2001-2021, a 74.1% increase. Horizontal drilling allows the wellbore to have more contact with the source rock, thus allowing more hydrocarbons to be extracted. Hydraulic fracturing allows oil and gas companies to have access to low permeable source rock, previously …


Development Of Methane Emissions Model To Assess Fuel Recovery Potential At Gas Well Sites Using On Site Compression, Nicholas G. Lindenfeldar 2022 West Virginia University

Development Of Methane Emissions Model To Assess Fuel Recovery Potential At Gas Well Sites Using On Site Compression, Nicholas G. Lindenfeldar

Graduate Theses, Dissertations, and Problem Reports (ETD)

The US natural gas production and consumption has increased 85.5% since 2005 primarily due to the unconventional production methods of horizontal drilling and hydraulic fracturing. Natural gas used as a fuel has a lower greenhouse gas (GHG) footprint than coal and petroleum due to lower Carbon Dioxide (CO2) emissions when combusted. However, the “greener” benefit to natural gas may be consumed by leaks in production and transmission systems. Methane (CH4), the primary hydrocarbon in natural gas, has an estimated Global Warming Potential (GWP) of 28-36 over 100 years, meaning it can absorb 28-36 more energy than …


Computational Analysis Of The Stability Limits Of Premixed Methane-Air Combustion In Micro-Channels, Almoutazbellah Adnan Kutkut 2022 West Virginia University

Computational Analysis Of The Stability Limits Of Premixed Methane-Air Combustion In Micro-Channels, Almoutazbellah Adnan Kutkut

Graduate Theses, Dissertations, and Problem Reports (ETD)

Technological progress in the last decades facilitated the development of integrated microsystem devices, including electrical and mechanical components for micro-electro-mechanical systems (MEMS). Such systems necessitate an external power supply, but typical batteries yet have some unavoidable limitations. To address this problem, numerous studies have been conducted to develop alternatives powered by micro combustion – in order to effectively utilize the high-density energy of hydrocarbon fuels. Such a global need has resulted in much more attention devoted to the combustion-based micro-power generation systems. However, to better understand the typical combustion characteristics in such microscale systems, design and performance restrictions need to …


Development Of A Thermal Desalination System Using Low Quality Thermal Energy, Takudzwa C. Chipunza 2022 West Virginia University

Development Of A Thermal Desalination System Using Low Quality Thermal Energy, Takudzwa C. Chipunza

Graduate Theses, Dissertations, and Problem Reports (ETD)

Abstract

Development of a Thermal Desalination System Using Low Quality Thermal Energy

Takudzwa Chipunza

The blowdown water from the cooling tower of the power plant and the produced water from shale gas industry cannot be disposed directly to the environment as they may contain dissolved solids that are harmful to the environment. A detailed physical and chemical process to remove the mineral and organic solids has been developed in West Virginia University. Such a process includes running the blowdown and produced water through a softening tank, activated carbon tank, and a reverse osmosis (RO) system. The RO reject contains a …


High Energy And Power Density Peptidoglycan Musclesthrough Super-Viscous Nanoconfined Water, Haozhen Wang, Zhi-Lun Liu, Jianpei Lao, Sheng Zhang, Rinat Abzalimov, Tong Wang, Xi Chen 2022 CUNY Advanced Science Research Center

High Energy And Power Density Peptidoglycan Musclesthrough Super-Viscous Nanoconfined Water, Haozhen Wang, Zhi-Lun Liu, Jianpei Lao, Sheng Zhang, Rinat Abzalimov, Tong Wang, Xi Chen

Advanced Science Research Center

Water-responsive (WR) materials that reversibly deform in response to humidity changes show great potential for developing muscle-like actuators for miniature and biomimetic robotics. Here, it is presented that Bacillus (B.) subtilis’ peptidoglycan (PG) exhibits WR actuation energy and power densities reaching 72.6 MJ m−3 and 9.1 MW m−3, respectively, orders of magnitude higher than those of frequently used actuators, such as piezoelectric actuators and dielectric elastomers. PG can deform as much as 27.2% within 110 ms, and its actuation pressure reaches ≈354.6 MPa. Surprisingly, PG exhibits an energy conversion efficiency of ≈66.8%, which can be attributed to its super-viscous nanoconfined …


Electro-Chemo-Mechanics Of The Interfaces In 2d-3d Heterostructure Electrodes, Vidushi Sharma 2021 New Jersey Institute of Technology

Electro-Chemo-Mechanics Of The Interfaces In 2d-3d Heterostructure Electrodes, Vidushi Sharma

Dissertations

Unique heterostructure electrodes comprising two-dimensional (2D) materials and bulk three dimensional (3D) high-performance active electrodes are recently synthesized and experimentally tested for their electrochemical performance in metal-ion batteries. Such electrodes exhibit long cycle life while they also retain high-capacity inherent to the active electrode. The role of 2D material is to provide a supportive mesh that allows buffer space for volume expansions upon ion intercalation in the active material and establishes a continuous electronic contact. Therefore, the binding strength between both materials is crucial for the success of such electrodes. Furthermore, battery cycles may bring about phase transformations in the …


Energy Planning Model Design For Forecasting The Final Energy Consumption Using Artificial Neural Networks, Haidy Eissa 2021 The American University in Cairo AUC

Energy Planning Model Design For Forecasting The Final Energy Consumption Using Artificial Neural Networks, Haidy Eissa

Theses and Dissertations

“Energy Trilemma” has recently received an increasing concern among policy makers. The trilemma conceptual framework is based on three main dimensions: environmental sustainability, energy equity, and energy security. Energy security reflects a nation’s capability to meet current and future energy demand. Rational energy planning is thus a fundamental aspect to articulate energy policies. The energy system is huge and complex, accordingly in order to guarantee the availability of energy supply, it is necessary to implement strategies on the consumption side. Energy modeling is a tool that helps policy makers and researchers understand the fluctuations in the energy system. Over the …


Solution-Processed Flexible Broadband Zno Photodetector Modified By Ag Nanoparticles, N. P. Klochko, K. S. Klepikova, I. V. Khrypunova, V. R. Kopach, I. I. Tyukhov, S. I. Petrushenko, S. V. Dukarov, V. M. Sukhov, M. V. Kirichenko, A. L. Khrypunova 2021 National Technical University “Kharkiv Polytechnic Institute”

Solution-Processed Flexible Broadband Zno Photodetector Modified By Ag Nanoparticles, N. P. Klochko, K. S. Klepikova, I. V. Khrypunova, V. R. Kopach, I. I. Tyukhov, S. I. Petrushenko, S. V. Dukarov, V. M. Sukhov, M. V. Kirichenko, A. L. Khrypunova

Faculty Research, Scholarly, and Creative Activity

In this work, we present flexible broadband photodetectors (PDs) fabricated by a deposition of nanostructured zinc oxide (ZnO) films on polyimide (PI) substrates by using cheap and scalable aqueous method Successive Ionic Layer Adsorption and Reaction (SILAR). In order to increase the long-wavelength absorption of the nanostructured ZnO layer, we created its intrinsic defects, including oxygen vacancies by post-treatment at 300 °C in vacuum and thus the light-sensitive material ZnO/PI was obtained. Then we applied silver nanoparticles (Ag NPs) from a silver sol onto a nanostructured ZnO film, which were visualized using SEM in the form of spheres up to …


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