bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optical Ray-Tracing Performance Modeling of Quartz Half-Shell Tubes Aperture Cover for Falling Particle Receiver
Authors: Yellowhair Julius , Ho Clifford K. 
Published: December 2019

Abstract
A 1 MWt falling particle receiver prototype was designed, built and is being evaluated at Sandia National Laboratories, National Solar Thermal Test Facility (NSTTF). The current prototype has a 1 m2 aperture facing the north field. The current aperture configuration is susceptible to heat and particle losses through the receiver aperture. Several options are being considered for the next design iteration to reduce the risk of heat and particle losses, in addition to improving the receiver efficiency to target levels of ∼90%. One option is to cover the receiver aperture with a highly durable and transmissive material such as quartz glass. Quartz glass has high transmittance for wavelengths less than 2.5 microns and low transmittance for wavelengths greater than 2.5 microns to help trap the heat inside the receiver.
To evaluate the receiver optical performance, ray-tracing models were set up for several different aperture cover configurations. The falling particle receiver is modeled as a box with a 1 m2 aperture on the north side wall. The box dimensions are 1.57 m wide × 1.77 m tall × 1.67 m deep. The walls are composed of RSLE material modeled as Lambertian surfaces with reflectance of either 0.9 for the pristine condition or 0.5 for soiled walls. The quartz half-shell tubes are 1.46 m long with 105 mm and 110 mm inner and outer diameters, respectively. The half-shell tubes are arranged vertically and slant forward at the top by 30 degrees. Four configurations were considered: concave side of the half-shells facing away from the receiver aperture with (1) no spacing and (2) high spacing between the tubes, and concave side of the half-shells facing the aperture with (3) no spacing and (4) high spacing between the tubes. The particle curtain, in the first modeling approach, is modeled as a diffuse surface with transmittance, reflectance, and absorptance values, which are based on estimates from previous experiments for varying particle flow rates. The incident radiation is from the full NSTTF heliostat field with a single aimpoint at the center of the receiver aperture. The direct incident rays and reflected and scattered rays off the internal receiver surfaces are recorded on the internal walls and particle curtain surfaces as net incident irradiance. The net incident irradiances on the internal walls and particle curtain for the different aperture cover configuration are compared to the baseline configuration. In all cases, just from optical performance alone, the net incident irradiance is reduced from the baseline. However, it is expected that the quartz half-shells will reduce the convective and thermal radiation losses through the aperture. These ray-tracing results will be used as boundary conditions in computational fluid dynamics (CFD) analyses to determine the net receiver efficiency and optimal configuration for the quartz half-shells that minimize heat losses and maximize thermal efficiency.
Numerical Simulation of Wave Energy Converter With Hydrofoil Blades Under Various Wave Conditions
Authors: Lei Jie , Gonzalez Erasmo , Yang Yingchen , Zhang Ying , Xu Ben 
Published: December 2019

Abstract
Ocean wave is a rich source of renewable energy with much higher power density than winds. Various WEC technologies have been proposed or are under development. In this study, we developed a 2-dimensional (2D) model and analyzed the rotational motion of the lift-type rotor’s blade under steady flow and unsteady flow. The numerical model was validated by experiments under steady flow. Fast Fourier Transform (FFT) analysis was performed to identify the major contribution of frequency in terms of vortexes generated in the flow field. A comparative study was also performed by comparing all the cases in terms of energy conversion efficiency under different wave conditions. It turns out that the efficiency of energy conversion has a maximum value in the steady flow, while the efficiency for unsteady flow keeps decreasing, therefore this is highly due to the increased dissipation because of the oscillating. When the flow is oscillating, the rotational speed of the rotor under periodic condition is lower than the rotational velocity with steady flow, and a curve fitting was performed in this study to predict the periodic average rotational speed. We conclude that for oscillating flow a minimum of 1.6% energy conversion efficiency can be expected, but it may vary for the actual ocean waves. It is expected the current 2D simulation results can contribute to the wave energy community, especially when the rotor design and optimization is required.
Decarbonizing Power Generation Through the Use of Hydrogen As a Gas Turbine Fuel
Authors: Welch Michael 
Published: December 2019

Abstract
The power generation industry has a major role to play in reducing global greenhouse gas emissions, and carbon dioxide (CO2) in particular. There are two ways to reduce CO2 emissions from power generation: improved conversion efficiency of fuel into electrical energy, and switching to lower carbon content fuels.
Gas turbine generator sets, whether in open cycle, combined cycle or cogeneration configuration, offer some of the highest efficiencies possible across a wide range of power outputs. With natural gas, the fossil fuel with the lowest carbon content, as the primary fuel, they produce among the lowest CO2 emissions per kWh generated. It is possible though to decarbonize power generation further by using the fuel flexibility of the gas turbine to fully or partially displace natural gas used with hydrogen. As hydrogen is a zero carbon fuel, it offers the opportunity for gas turbines to produce zero carbon electricity. As an energy carrier, hydrogen is an ideal candidate for long-term or seasonal storage of renewable energy, while the gas turbine is an enabler for a zero carbon power generation economy.
Hydrogen, while the most abundant element in the Universe, does not exist in its elemental state in nature, and producing hydrogen is an energy-intensive process. This paper looks at the different methods by which hydrogen can be produced, the impact on CO2 emissions from power generation by using pure hydrogen or hydrogen/natural gas blends, and how the economics of power generation using hydrogen compare with today’s state of the art technologies and carbon capture. This paper also addresses the issues surrounding the combustion of hydrogen in gas turbines, historical experience of gas turbines operating on high hydrogen fuels, and examines future developments to optimize combustion emissions.
Evolution Algorithms and Biomass Properties Prediction: A Review
Authors: Olatunji Obafemi , Akinlabi Stephen , Madushele Nkosinathi , Adedeji Paul , Fatoba Samuel 
Published: December 2019

Abstract
The complexity of real-world applications of biomass energy has increased substantially due to so many competing factors. There is an ongoing discussion on biomass as a renewable energy source and its cumulative impact on the environment vis-a-vis water competition, environmental pollution and so on. This discussion is coming at a time when evolutionary algorithms and its hybrid forms are gaining traction in several applications. In the last decade, evolution algorithms and its hybrid forms have evolved as a significant optimization and prediction technique due to its flexible characteristics and robust behaviour. It is very efficient means of solving complex global optimization problems. This article presents the state-of-the-art review of different types of evolutionary algorithms, which have been applied in the prediction of major properties of biomass such as elemental compositions and heating values. The governing principles, applications, merits, and challenges associated with this technique are elaborated. The future directions of the research on biomass properties prediction are discussed.
Applications of Geothermal Energy in Space Cooling: A Simulator Study of Existing Oil Well to Activate an Absorption Chiller
Authors: Ghaith Fadi A. , Wars Kamal Majlab 
Published: December 2019

Abstract
This paper addresses the potential of integrating the existing oil wells and absorption chiller for the purpose of provision space cooling for the base camp of oil field at Block 9 located in Oman. The wellbore was used as a hot water feed to the chiller. Well S 347 was selected as the hot water source and well S 179 was selected to be the injection well for the outlet water.
The existing wells were assessed via PIPESIM software. Using PIPESIM software, the fluid temperatures, well pressure and flow rates were obtained and analyzed throughout NODAL analyses. The water temperature of 100 °C, well head pressure of 100 psi and flow rate of 30 m3/h, were found to be the optimum operating parameters. The COP of the absorption chiller was obtained via ABSIM software. The variable operating conditions were investigated and elaborated as a function of the efficiency and capacity ratio. The designed system was configured to yield 0.733 COP and a capacity of 377 KW which met the cooling capacity of the admin building of block 9. The entire feasibility analysis was performed in terms of the overall cost as well as the saving that would be achieved from such homogeneity. The payback period of the entire system was found to be 7 years which emphasized a great potential of adapting the technology if the operating resources are available.
Risk Assessment on Working Fluid Selection for Closed-Cycle Gas Turbine Systems
Authors: Osigwe Emmanuel O. , Pilidis Pericles , Nikolaidis Theoklis , Igbong Dodeye 
Published: December 2019

Abstract
From a thermodynamic viewpoint, it is almost possible to utilize all permanent gases as a working fluid for closed-cycle gas turbine energy conversion system. However, this possibility could be limited due to several criteria, some of which are dictated by both technological and economic requirements. This paper provides a risk assessment on possible uncertainties and operational challenges for selected working fluids such as helium, carbon-dioxide, nitrogen and air, which could impact on the closed-cycle gas turbine technology. The risk assessment presented in this paper is described in two parts which include; technological and financial risk. The technological risk gives an assessment on the effect of the selected working fluids on components material technology, turbine entry temperature, and fluid management system while the financial risk aspect gives an assessment in terms of system cost implications influenced by the working fluids and the impact of legislation on investment decision. The overarching discussions from this paper show that helium has an advantage of a possible compact design which could undoubtedly be important cost savings, however, due to government policies on its availability, the operational cost for using helium could make it a huge disadvantage compared with other working fluids discussed in this paper.
Unsteady Simulation on Flow Characteristics of Steam Jet Condensed Into Subcooled Water
Authors: Song Shilin , Chong Daotong , Zhao Quanbin , Chen Weixiong , Yan Junjie 
Published: December 2019

Abstract
Steam jet condensation through sonic nozzle in quiescent subcooled water pool is important for the safety of nuclear reactor system. In this study, the dynamic process of stable condensation jet steam plume is obtained by numerical simulation method. The simulation results are in good agreement with the experimental results. The flow field results indicate that two typical fluctuation regimes exist in the dynamic process of steam plume. Simultaneous analysis of pressure and flow field indicates that two fluctuation regimes produce different pressure pulses. When the detachment phenomenon occurs during the fluctuation of the steam plume, a pressure pulse which value is clearly greater than 220 kPa is generated. When the plume sharply contracts without obvious detachment phenomenon during the fluctuation process, a pressure pulse which value is almost lower than 120 kPa is generated.
Effects of Fission Profiles on the Performance of a U-10Mo Fuel Plate
Authors: Roh Hee Seok , Mohamed Walid , Ozaltun Hakan 
Published: December 2019

Abstract
In order to convert the high-performance research reactors from High Enriched Uranium (HEU) to Low Enriched Uranium (LEU) fuel, U-Mo alloy-based fuels in monolithic form have been proposed. These plate-type fuels consist of a high density and low enriched uranium (LEU) foil coated with a diffusion barrier and encapsulated with the aluminum cladding. The performance of the fuel plate has been evaluated by many studies through experimental tests and numerical analyses. When evaluating the performance of a fuel, it is expensive and time-consuming to consider a variation of several parameters, such as fuel plate geometry, material properties, and operating conditions. Fission profile is a critical component of the fuel performance analysis, causing swelling and creep deformation of the fuel plate. Therefore, it can directly affect the stress and strain distributions over the fuel plate. This study aims at investigating the effect of different fission profiles on the thermo-mechanical performance of the fuel plate by finite element analysis. To investigate the effect of fission profile on fuel performance, several different fission profiles were generated and analyzed. The fission profiles were generated based on actual use.
How do the new Olympic sports compare with the traditional Olympic sports? Injury and illness at the 2018 Youth Olympic Summer Games in Buenos Aires, Argentina
Authors: Steffen Kathrin , Soligard Torbjørn , Mountjoy Margo , Dallo Ignacio , Gessara Alan Maximiliano , Giuria Hernan , Perez Alamino Leonel , Rodriguez Joaquin , Salmina Natalia , Veloz Daniel , Budgett Richard , Engebretsen Lars 
Published: December 2019

ObjectiveTo describe injuries and illnesses across traditional and new sports among the participating athletes of the Buenos Aires 2018 Youth Olympic Summer Games (BA YOG) (6–18 October 2018).MethodsWe recorded the daily number of athlete injuries and illnesses (1) through the reporting of all National Olympic Committee (NOC) medical teams and (2) in the polyclinic and medical venues manned by the BA YOG 2018 medical staff.ResultsIn total, 3.984 athletes from 206 NOCs were observed. NOCs and BA YOG 2018 medical staff reported 619 injuries and 334 illnesses, equalling 15.5 injuries and 8.4 illnesses per 100 athletes over the 13-day period. The eight new sports on the Youth Olympic programme (futsal, beach handball, karate, roller speed skating, kitesurfing, BMX freestyle, climbing and break dancing) fell in between the other sports with respect to injury and illness risk. Injury incidence was highest in rugby (43% of all rugby players), followed by boxing (33%) and badminton (24%), and lowest in swimming, archery, roller speed skating, equestrian, climbing and rowing (<5%). The highest incidences of illness were recorded in golf (20%), followed by triathlon (16%), beach volleyball and diving (both 14%). Of the illnesses, 50% affected the respiratory system and 15% the gastrointestinal system. Injury and illness incidences varied between continents with athletes representing Europe having significantly fewer injuries and illnesses compared with other continents, apart from a similar illness incidence to Asian athletes.ConclusionThe overall injury incidence of 15.5 injuries per 100 athletes was higher, while the overall illness incidence of 8.4 illnesses per 100 athletes was similar to previous youth and Olympic Games. The new sports did not differ significantly compared with the other sports with respect to injury and illness risk.
Organic or organised: an interaction analysis to identify how interactional practices influence participation in group decision meetings for residency selection
Authors: Gennissen Lokke , de la Croix Anne , Stegers-Jager Karen , de Graaf Jacqueline , Fluit Cornelia R M G , de Hoog Matthijs 
Published: December 2019

ObjectivesThis study aims to shed light on interactional practices in real-life selection decision-making meetings. Adequate residency selection is crucial, yet currently, we have little understanding of how the decision-making process takes place in practice. Since having a wide range of perspectives on candidates is assumed to enhance decision-making, our analytical focus will lie on the possibilities for committee members to participate by contributing their perspective.DesignWe analysed interaction in seven recorded real-life selection group decision meetings, with explicit attention to participation.SettingSelection meetings of four different highly competitive specialties in two Dutch regions.Participants54 participants discussed 68 candidates.MethodsTo unravel interactional practices, group discussions were analysed using a hybrid data-driven, iterative analytical approach. We paid explicit attention to phenomena which have effects on participation. Word counts and an inductive qualitative analysis were used to identify existing variations in the current practices.ResultsWe found a wide variety of practices. We highlight two distinct interactional patterns, which are illustrative of a spectrum of turn-taking practices, interactional norms and conventions in the meetings. Typical for the first pattern—‘organised’—is a chairperson who is in control of the topic and turn-taking process, silences between turns and a slow topic development. The second pattern—‘organic’—can be recognised by overlapping speech, clearly voiced disagreements and negotiation about the organisation of the discussion. Both interactional patterns influence the availability of information, as they create different types of thresholds for participation.ConclusionsBy deconstructing group decision-making meetings concerning resident selection, we show how structure, interactional norms and conventions affect participation. We identified a spectrum ranging from organic to organised. Both ends have different effects on possibilities for committee members to participate. Awareness of this spectrum might help groups to optimise decision processes by enriching the range of perspectives shared.
Storytelling as a research tool and intervention around public health perceptions and behaviour: a protocol for a systematic narrative review
Authors: McCall Becky , Shallcross Laura , Wilson Michael , Fuller Christopher , Hayward Andrew 
Published: December 2019

IntroductionThere is a growing trend to use storytelling as a research tool to extract information and/or as an intervention to effect change in the public knowledge, attitudes and behaviour (KAB) in relation to public health issues, primarily those with a strong element of disease prevention. However, evidence of its use in either or both capacities is limited. This protocol proposes a systematic narrative review of peer-reviewed, published literature on the use of storytelling as a research tool within the public health arena.Methods and analysisMedline, EMBASE, PsycINFO, ERIC (Educational Resources Information Center), Web of Science, Art and Humanities database (ProQuest), Scopus and Google Scholar will be searched for studies that look at the use of storytelling in the research of pressing current public health issues, for example, vaccinations, antimicrobial resistance, climate change and cancer screening. The review will synthesise evidence of how storytelling is used as a research tool to (a) gain insights into KAB and (b) to effect change in KAB when used as an intervention. Included studies will be selected according to carefully defined criteria relevant to public health issues of interest, and data from qualitative, quantitative and mixed-methods studies will be extracted with a customised data extraction form. A narrative synthesis will be performed according to Economic and Social Research Council guidance from Popay, J, 2006.The study protocol follows the recommendations by the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P).Ethics and disseminationFormal ethical approval is not required for this study, as no primary data will be collected. Dissemination will involve publishing results of this study in relevant peer-reviewed journal(s). Where possible, the study results will also be presented as posters or talks at relevant medical conferences and meetings.PROSPERO registration numberCRD42019124704
High‐grade astrocytoma with ventricular invasion in a dog
Authors: Pupin Rayane Chitolina , Rissi Daniel R , Gomes Danilo Carloto , Gimelli Amanda , Palumbo Mariana Isa Poci 
Published: December 2019

A 13‐year‐old female German Shepherd dog was euthanised and submitted to necropsy after a 7‐month history of prolonged recumbency and vocalisation. Gross anatomical changes consisted of a well‐demarcated, 3.5×1.5 cm, soft red mass that effaced the right lateral ventricle and compressed the adjacent neuroparenchyma. Histologically, elongate neoplastic cells with astrocytic morphology were arranged in short bundles and streams supported by a neuropil‐like stroma. Neoplastic cells were immunopositive for glial fibrillar acidic protein (GFAP) and oligodendrocyte transcription factor 2 (Olig2), and immunonegative for e‐cadherin and pancytokeratin. Histological and immunohistochemical features were consistent with a high‐grade astrocytoma with ventricular invasion, a rare feature of astrocytic tumours in dogs.
Duffin–Kemmer–Petiau equation: Casimir effect and Stefan–Boltzmann law at finite temperature
Authors: Furtado T. F. , Ulhoa S. C. , Khanna F. C. , Amorim R. G. G. 
Published: December 2019

This work deals with the Duffin–Kemmer–Petiau (DKP) field theory. The structure of the wave functions is analyzed for the scalar and vector sectors for particles with spin 0 and spin 1. The finite temperature is introduced using Thermo Fields Dynamics (TFD). It is a mathematical approach which involves doubling of the Hilbert space to introduce finite temperature. Results for Stefan–Boltzmann law and Casimir effect in DKP field are calculated at finite temperature.
Diagnostic Metrics for Evaluating Model Simulations of the East Asian Monsoon
Authors: Li Juan , Wang Bin , Yang Young-Min 
Published: December 2019

AbstractThe distinctive monsoon climate over East Asia, which is affected by the vast Eurasian continent and Pacific Ocean basin and the high-altitude Tibetan Plateau, provides arguably the best testbed for evaluating the competence of Earth system climate models. Here, a set of diagnostic metrics, consisting of 14 items and 7 variables, is specifically developed. This physically intuitive set of metrics focuses on the essential features of the East Asian summer monsoon (EASM) and East Asian winter monsoon (EAWM), and includes fields that depict the climatology, the major modes of variability, and unique characteristics of the EASM. The metrics are applied to multimodel historical simulations derived from 20 models that participated in phases 3 and 5 of the Coupled Model Intercomparison Project (CMIP3 and CMIP5, respectively), along with the newly developed Nanjing University of Information Science and Technology Earth System Model, version 3. The CMIP5 models show significant improvements over the CMIP3 models in terms of the simulated East Asian monsoon circulation systems on a regional scale, major modes of EAWM variability, the monsoon domain and precipitation intensity, and teleconnection associated with the heat source over the Philippine Sea. Clear deficiencies persist from CMIP3 to CMIP5 with respect to capturing the major modes of EASM variability, as well as the relationship between the EASM and ENSO during El Niño developing and decay phases. The possible origins that affect models’ performance are also discussed. The metrics provide a tool for evaluating the performance of Earth system climate models, and facilitating the assessment of past and projected future changes of the East Asian monsoon.