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Tilted global solar irradiance in Bahrain:an experimental study

Clean Energy 2024年第2期8卷 27-34页

作者： N.Vasilikos C.Georgantopoulou h.Alajaimi s.h.Almajed m.Ahmed D.mathioulakis school of mechanical Engineering Bahrain PolytechnicIsa TownPO Box 33349Kingdom of Bahrain school of mechanical Engineering National Technical University of AthensHeroon Polytechniou 7 StZografos 15773AthensGreece

In the present work,tilted global solar irradiance data are presented and analysed,measured for a period of 1 year on the campus of Bahrain Polytechnic,Kingdom of Bahrain,from both a fixed photovoltaic panel and a moving one via a two-axis solar *** fixed panel faces south with an angle of 26°with respect to the horizontal,coinciding with the local geographical *** second panel is moved by two motors,controlled by a global positioning system and suitable software so that the sun’s rays are perpendicular to the panel surface.A pyranometer is installed on each panel,recording the tilted global solar irradiance,stored by using a data *** analysis of the data obtained shows a 33%solar energy gain on an annual basis for the moving panel(2780 versus 2088 kWh/m^(2) on the fixed panel).more importantly,in June,when the energy demand in Bahrain is elevated due to the increased residential cooling loads,the solar energy received by the moving panel is 54.7%higher compared with that of the fixed *** a percentage basis,the increase in solar energy from the moving panel is profound in the early morning and late evening ***,the reduction in the solar energy received by the fixed panel from may to June does not appear in the moving panel because of the adjustable orientation of the *** the year,the mean daily solar power varies between 0.37 and 0.56 kW/m^(2) for the fixed panel,and 0.45 and 0.70 kW/m^(2) for the moving *** winter,solar energy fluctuations are elevated due to erratic weather conditions that present a peak standard deviation of 28%of the corresponding *** data presented are useful for potential solar investments in Gulf countries.

关键词： tilted solar irradiance renewable energy solar tracking photovoltaic Gulf Cooperation Council Countries

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Parametric investigation on the novel and cost-effective nano fly ash impregnated geopolymer system for sustainable construction

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Frontiers of structural and Civil Engineering 2024年第2期18卷 170-183页

作者： R.mOhANA s.m.Leela BhARAThI Department of Civil Engineering Mepco Schlenk Engineering CollegeSivakasi 626123India

The hazardous environmental effects of greenhouse gas emissions and climate change demand alternative sources for cementitious materials in the construction *** development of geopolymer structures provides a way of producing 100%cement-free *** this research work,a novel and simple way of deriving nano particles from waste fly ash particles is *** effect of adding the synthesized nano fly ash particles as a filler medium in geopolymer mortars was investigated by considering strength and durability *** optimization was done by using regression analysis on the geopolymer mortar and the impact of adding nano fly ash particles was studied by varying different percentages of addition ranging from 0 to 7.5%by weight of binder *** the results,it was observed that 1%nano fly ash acted not only as a filler but also as nano-sized precursors of the polymerization process,resulting in denser geopolymer *** can explain the extraordinary gain in strength of 72.11 mPa as well as the denser core with negligible level of chloride ion penetration,making the material suitable for the development of structures susceptible to marine environment.

关键词： geopolymer nano fly ash chloride ion penetration durability polymerization fillers

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model dependent analysis of ■→■ decays in beyond standard model

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Chinese Physics C 2024年第9期48卷 86-99页

作者： s.mahata m.mandal h.mahapatra s.Biswas s.sahoo Department of Physics National Institute of Technology Durgapur

motivated by the recent experimental results of branching fractions for ■→■ decays,which deviate from their sm predictions,we hve investigated these decays in W' model and scalar leptoquark model to determine potential signatures of new physics(NP) in semileptonic charm decays induced by c→■ *** recent experimental results of branching fractions for semileptonic D meson decays,new coupling parameters are predicted for the aforementioned NP *** fraction,forward-backward asymmetry,and lepton polarization asymmetry are examined by considering the predicted NP coupling *** results of branching fractions in scalar leptoquark model are found very close to the experimental results and exist around the range of 1σ *** presented a comparative study of the NP models to check their sensitivity on these *** anticipate that further research on these decays will significantly support our findings.

关键词： $ W' $ boson charm decay flavour changing charged current new physics scalar leptoquark

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model dependent analysis of D^(+)_(s)→η^(′)l+v_(l) decays in beyond standard model

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Chinese Physics C 2024年第9期48卷 82-95页

作者： s.mahata m.mandal h.mahapatra s.Biswas s.sahoo Department of Physics National Institute of Technology Durgapur Durgapur 713209West BengalIndia

motivated by the recent experimental results of branching fractions for D^(+)_(s)→η^(′)l+v_(l) decays,which deviate from their sm predictions,we hve investigated these decays in W' model and scalar leptoquark model to determine potential signatures of new physics(NP) in semileptonic charm decays induced by c→(s,d)l+v_(l) *** recent experimental results of branching fractions for semileptonic D meson decays,new coupling parameters are predicted for the aforementioned NP *** fraction,forward-backward asymmetry,and lepton polarization asymmetry are examined by considering the predicted NP coupling *** results of branching fractions in scalar leptoquark model are found very close to the experimental results and exist around the range of 1σ *** presented a comparative study of the NP models to check their sensitivity on these *** anticipate that further research on these decays will significantly support our findings.

关键词： charm decay new physics W′boson scalar leptoquark flavour changing charged current

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Background removal from global auroral images:Data-driven dayglow modeling

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Earth and Planetary Physics 2024年第1期8卷 247-257页

作者： A.Ohma m.madelaire K.m.Laundal J.P.Reistad s.m.hatch s.Gasparini s.J.Walker Birkeland Centre for space science Department of Physics and TechnologyUniversity of BergenBergenNorway

Global images of auroras obtained by cameras on spacecraft are a key tool for studying the near-Earth ***,the cameras are sensitive not only to auroral emissions produced by precipitating particles,but also to dayglow emissions produced by photoelectrons induced by *** emissions and scattered sunlight can contribute to the background *** fully utilize such images in space science,background contamination must be removed to isolate the auroral *** we outline a data-driven approach to modeling the background intensity in multiple images by formulating linear inverse problems based on B-splines and spherical *** approach is robust,flexible,and iteratively deselects outliers,such as auroral *** final model is smooth across the terminator and accounts for slow temporal variations and large-scale asymmetries in the *** demonstrate the model by using the three far ultraviolet cameras on the Imager for magnetopause-to-Aurora Global Exploration(ImAGE)*** method can be applied to historical missions and is relevant for upcoming missions,such as the solar wind magnetosphere Ionosphere Link Explorer(smILE)mission.

关键词： aurora dayglow modeling global auroral images far ultraviolet images dayglow removal

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Novel synthesis of stabilized Bi1-x-yGdxDyyO1.5 solid electrolytes with enhanced conductivity for intermediate temperature solid oxide fuel cells（sOFCs）

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Journal of Rare Earths 2024年第10期42卷 1903-1911页

作者： Ahmed h.Ibrahim Yehia m.Abbas h.A.Ayoub marwa h.Ali mustafa Aldoori materials science Laboratory Physics DepartmentFaculty of ScienceSuez Canal University ministry of higher Education and scientific Research Aliraqia University

herein,we report the synthesis of a Dy-Gd co-doped cubic phase-stabilized Bi2O3solid electrolyte system via solid-state processing under atmospheric *** with Dy3+and Gd3+has been observed to significantly enhance the densification process during sintering for stabilization purposes,thereby improving the electrical properties of δ-Bi2O3-type *** synthesized ceramics were characterized using X-ray diffraction（XRD）,field emission scanning electron microscopy-energy dispersive X-ray spectroscopy（FEsEm-EDX）,thermal gravimetry/differential thermal analysis（TG/DTA）,and the four-point probe technique（4PPT）.XRD analysis reveals that the samples Bi1-x-yGdxDyyO1.5（y=0.05/x=0.05,0.10,0,15,and 0.20,and x=0.05/y=0.10,0.15,and 0.20） exhibit a stable face-centered cubic δ-phase and a mixed-phase crystallographic *** XRD analysis of the stabilized δ-phase suggests that the prepared oxides show a face-centered cubic（FCC） structure with a space group of *** micrographs reveal that the composition Bi0.90Gd0.05Dy0.05O1.5has no significant ***,an evident increase in the pore formation is observed as the amount of Gd2O3increases until it reaches 20%.This finding suggests that dense pellets are formed during the sintering process at 900-1000℃.The DTA analyses were performed to verify the phase stability,which agrees with the XRD *** electrochemical performance of the synthesized Dy-Gd co-doped Bi2O3solid electrolyte system was evaluated and analyzed in detail by using the electrochemical impedance spectroscopy（EIs） technique,Based on EIs and conductivity measurements,Bi0.75Gd0.20Dy0.05O1.5exhibits the lowest activation energy of 0.519 eV and the highest conductivity value of 0.398 s/cm at 627℃compared to the other samples;this composition can be used as a solid electrolyte for intermediatetemperature solid oxide fuel cells（sOFCs）.

关键词： Electrochemical impedance spectroscopy (EIs) Fast Fourier transform (FFT) Rare earths Rietveld solid oxide fuel cells (sOFCs) solid-state processing

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Effect of radiative loss mechanisms on FIR thermometric parameters of Nd^(3+)-doped lithium tellurite glasses

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Journal of Rare Earths 2024年第7期42卷 1250-1257,I0002页

作者： C.Y.morassuti A.P.L silva L.A.O.Nunes s.m.Lima L.h.C.Andrade Optical and Photothermal spectroscopy Group(GEOF) Center for Studies in Natural Resources(CERNA)State University of Mato Grosso do Sul(UEMS)C.P.351DouradosMSBrazil Renato Archer Information Technology Center Dom Pedro I Highway(SP-65)Km 1436-Chácaras Campos dos AmaraisCampinasSPBrazil Institute of Physics of são Carlos University of São PauloSão CarlosSPBrazil

Nd^(3+)-doped tellurite glasses are promising materials for thermometers based on the fluorescence intensity ratio(FIR)***,at high Nd^(3+)concentrations,energy transfer(ET)processes such as optical reabsorption and cross-relaxation can affect the Nd^(3+)emission,which has been little explored in the ***,the present work investigated the use of Nd^(3+)-doped tellurite glass(samples doped with Nd^(3+)at 0.2 mol%,0.5 mol%,2.0 mol%,and 4.0 mol%)in fluorescence thermometers,in the temperature range from 299 to 371 *** results indicate a strong dependence of the FIR parameters on the Nd^(3+)concentration,due to changes in the emission band profiles caused by optical reabsorption of the Nd^(3+)emissions and cross-relaxation processes.A decrease of the relative sensitivity of the ratio^(4)F_(5/2)→^(4)I_(9/2)/^(4)F_(3/2)→^(4)I_(9/2)is observed for samples doped with higher amounts of Nd^(3+).The maximum relative sensitivity at 299 K is 3.00%/K,which is the highest value among the reported Nd^(3+)ions.

关键词： Nd^(3+)-doped tellurite glass Fluorescence intensity ratio Optical thermometry Judd-Ofelt Rare earths

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Exact solutions for magnetohydrodynamic nanofluids flow and heat transfer over a permeable axisymmetric radially stretching/shrinking sheet

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Chinese Physics B 2024年第2期33卷 108-114页

作者： U.s.mahabaleshwar G.P.Vanitha L.m.Pérez Emad h.Aly I.Pop Department of studies in mathematics Davangere UniversityShivagangothriDavangereIndia Departamento de F´ısica FACIUniversidad de Tarapac´aCasilla 7DAricaChile Department of mathematics Faculty of EducationAin Shams UniversityRoxyCairoEgypt Department of mathematics Babes-Bolyai University400084 Cluj-NapocaRomania

We report on the magnetohydrodynamic impact on the axisymmetric flow of Al_(2)O_(3)/Cu nanoparticles suspended in h_(2)O past a stretched/shrinked *** the use of partial differential equations and the corresponding thermophysical characteristics of nanoparticles,the physical flow process is *** resultant nonlinear system of partial differential equations is converted into a system of ordinary differential equations using the suitable similarity *** transformed differential equations are solved *** of the magnetic parameter,solid volume fraction and stretching/shrinking parameter on momentum and temperature distribution have been analyzed and interpreted *** skin friction and Nusselt number were also *** addition,existence of dual solution was deduced for the shrinking sheet and unique solution for the stretching ***,Al_(2)O_(3)/h_(2)O nanofluid flow has better thermal conductivity on comparing with Cu/h_(2)O ***,it was found that the first solutions of the stream are stable and physically realizable,whereas those of the second ones are unstable.

关键词： magnetohydrodynamic nanofluid stretching/shrinking sheet axisymmetric flow analytical solution suction/injection

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Leveraging User-Generated Comments and Fused BiLsTm models to Detect and Predict Issues with mobile Apps

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Computers, materials & Continua 2024年第4期79卷 735-759页

作者： Wael m.s.Yafooz Abdullah Alsaeedi Department of Computer science College of Computer Science and EngineeringTaibah UniversityMedina42353Saudi Arabia

In the last decade, technical advancements and faster Internet speeds have also led to an increasing number ofmobile devices and users. Thus, all contributors to society, whether young or old members, can use these mobileapps. The use of these apps eases our daily lives, and all customers who need any type of service can accessit easily, comfortably, and efficiently through mobile apps. Particularly, saudi Arabia greatly depends on digitalservices to assist people and visitors. such mobile devices are used in organizing daily work schedules and services,particularly during two large occasions, Umrah and hajj. however, pilgrims encounter mobile app issues such asslowness, conflict, unreliability, or user-unfriendliness. Pilgrims comment on these issues on mobile app platformsthrough reviews of their experiences with these digital services. scholars have made several attempts to solve suchmobile issues by reporting bugs or non-functional requirements by utilizing user ***, solving suchissues is a great challenge, and the issues still exist. Therefore, this study aims to propose a hybrid deep learningmodel to classify and predict mobile app software issues encountered by millions of pilgrims during the hajj andUmrah periods from the user perspective. Firstly, a dataset was constructed using user-generated comments fromrelevant mobile apps using natural language processing methods, including information extraction, the annotationprocess, and pre-processing steps, considering a multi-class classification problem. Then, several experimentswere conducted using common machine learning classifiers, Artificial Neural Networks (ANN), Long short-Termmemory (LsTm), and Convolutional Neural Network Long short-Term memory (CNN-LsTm) architectures, toexamine the performance of the proposed model. Results show 96% in F1-score and accuracy, and the proposedmodel outperformed the mentioned models.

关键词： mobile apps issues play store user comments deep learning LsTm bidirectional LsTm

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A hybrid machine-learning model for solar irradiance forecasting

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Clean Energy 2024年第1期8卷 100-110页

作者： Ameera m.Almarzooqi maher maalouf Tarek h.m.El-Fouly Vasileios E.Katzourakis mohamed s.El moursi Constantinos V.Chrysikopoulos Department of Industrial and systems Engineering Khalifa UniversityAbu DhabiPO Box 127788UAE Electrical Engineering and Computer science Department Khalifa University Abu DhabiUAE Department of Civil Infrastructure and Environmental Engineering Khalifa UniversityAbu DhabiPO Box 127788UAE school of Chemical and Environmental Engineering Technical University of CreteChaniaGreece

Nowcasting and forecasting solar irradiance are vital for the optimal prediction of grid-connected solar photovoltaic(PV)power *** plants face operational challenges and scheduling dispatch difficulties due to the fluctuating nature of their power *** the generation capacity within the electric grid increases,accurately predicting this output becomes increasingly essential,especially given the random and non-linear characteristics of solar irradiance under variable weather *** study presents a novel prediction method for solar irradiance,which is directly in correlation with PV power output,targeting both short-term and medium-term forecast *** proposed hybrid framework employs a fast trainable statistical learning technique based on the truncated-regularized kernel ridge regression *** proposed method excels in forecasting solar irradiance,especially during highly intermittent weather periods.A key strength of our model is the incorporation of multiple historical weather parameters as inputs to generate accurate predictions of future solar irradiance values in its scalable *** evaluated the performance of our model using data sets from both cloudy and sunny days in seattle and medford,UsA and compared it against three forecasting models:persistence,modified 24-hour persistence and least *** on three widely accepted statistical performance metrics(root mean squared error,mean absolute error and coefficient of determination),our hybrid model demonstrated superior predictive accuracy in varying weather conditions and forecast horizons.

关键词： solar power generation kernel ridge regression hybrid model forecasting

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