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Space-Fractional Diffusion with Variable Order and Diffusivity:Discretization and Direct Solution Strategies

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Communications on Applied Mathematics and Computation 2022年第4期4卷 1416-1440页

作者： Hasnaa Alzahrani George Turkiyyah omar Knio David Keyes King Abdullah University of Science and Technology ThuwalSaudi Arabia

We consider the multidimensional space-fractional diffusion equations with spatially varying diffusivity and fractional *** computational challenges are encoun-tered when solving these equations due to the kernel singularity in the fractional integral operator and the resulting dense discretized operators,which quickly become prohibitively expensive to handle because of their memory and arithmetic *** this work,we present a singularity-aware discretization scheme that regularizes the singular integrals through a singularity subtraction technique adapted to the spatial variability of diffusiv-ity and fractional *** regularization strategy is conveniently formulated as a sparse matrix correction that is added to the dense operator,and is applicable to different formula-tions of fractional diffusion *** also present a block low rank representation to handle the dense matrix representations,by exploiting the ability to approximate blocks of the resulting formally dense matrix by low rank factorizations.A Cholesky factorization solver operates directly on this representation using the low rank blocks as its atomic com-putational tiles,and achieves high performance on multicore *** results show that the singularity treatment is robust,substantially reduces discretization errors,and attains the first-order convergence rate allowed by the regularity of the *** also show that considerable savings are obtained in storage(O(N^(1.5)))and computational cost(O(N^(2)))compared to dense *** translates to orders-of-magnitude savings in memory and time on multidimensional problems,and shows that the proposed methods offer practical tools for tackling large nonlocal fractional diffusion simulations.

关键词： Fractional diffusion Variable order Variable diffusivity Singularity subtraction Block low rank matrix Tile low rank(TLR)Cholesky

Neutronic study on the effect of first wall material thickness on tritium production and material damage in a fusion reactor

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Nuclear Science and Techniques 2022年第4期33卷 33-50页

作者： HacıMehmet S¸ahin Güven Tunc¸ Alper Karakoc¸ Melood Mohamad omar Department of Energy Systems Engineering Technology FacultyKarabuk UniversityKarabukTurkey Department of Energy Systems Engineering Technology FacultyGazi UniversityAnkaraTurkey Department of Energy Systems Engineering Institute of Graduate ProgramsKarabuk UniversityKarabukTurkey

In this study,the effects of changing first wall materials and their thicknesses on a reactor were investigated to determine the displacement per atom(DPA)and gas production(helium and hydrogen)in the first wall,as well as the tritium breeding ratio(TBR)in the coolant and tritium breeding ***,the modeling of the magnetic fusion reactor was determined based on the blanket parameters of the International Thermonuclear Experimental Reactor(ITER).Stainless steel(SS 316 LNIG),Oxide Dispersion Strengthened Steel alloy(PM2000 ODS),and China low-activation martensitic steel(CLAM)were used as the first wall(FW)*** family molten salt materials(FLiBe,FLiNaBe,FLiPb)and lithium oxide(LiO_(2))were considered the coolant and tritium production material in the blanket,*** transport calculations were performed using the wellknown 3D code MCNP5 using the continuous-energy Monte Carlo *** built-in continuous energy nuclear and atomic data libraries along with the Evaluated Nuclear Data file(ENDF)system(ENDF/B-V and ENDF/B-VI)were ***,the activity cross-section data library CLAW-IV was used to evaluate both the DPA values and gas production of the first wall(FW)*** interface computer program written in the FORTRAN 90 language to evaluate the MCNP5 outputs was developed for the fusion reactor *** results indicated that the best TBR value was obtained for the use of the FLiPb coolant,whereas depending on the thickness,the first wall replacement period in terms of radiation damage to all materials was between 6 and 11 years.

关键词： ITER First wall material Material damage Tritium breeding ratio Fluorides family molten salt materials

True grit: ingestion of small stone particles by hummingbirds in West Mexico

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Avian Research 2021年第4期12卷 739-749页

作者： omar Maya-García Mauricio Ortega-Flores Jorge E.Schondube Posgrado en Ciencias Biológicas Unidad de PosgradoCoordinación del Posgrado en Ciencias BiológicasUniversidad Nacional Autónoma de MéxicoEdificio D1er pisoCircuito de PosgradosCiudad UniversitariaDel.CoyoacánC.P.04510 México D.F.Mexico Laboratorio de Ecología Funcional Instituto de Investigaciones en Ecosistemas y SustentabilidadUniversidad Nacional Autónoma de MéxicoAntigua Carretera a Pátzcuaro No.8701Col.Ex Hacienda de San Joséde la HuertaC.P.58190 MoreliaMichoacánMexico

Background: Grit is used by birds mainly for grinding hard food items but can also serve a nutritional role as a source of minerals. Ingestion of grit by birds has been documented primarily in species that feed on seeds and *** feeding mainly on nectar and small arthropods, hummingbirds also ingest grit, but why they do so is unclear. We quantified the number of grit particles in the stomachs of six species of hummingbirds during an annual cycle in a seasonal ecosystem of West ***: We compared the number of grit particles in the stomachs of different hummingbird species(Mexican Violetear Colibri thalassinus, Amethyst-throated Mountaingem Lampornis amethystinus, White-eared Hummingbird Basilinna leucotis, Rivoli's Hummingbird Eugenes fulgens, Broad-tailed Hummingbird Selasphorus platycercus, and Rufous Hummingbird S. rufus), and between sex and age categories during the different seasons of a year. To deter-mine if grit was used to grind ingested arthropods, we examined the relationships between the number of grit parti-cles, the biomass of arthropods ingested, and their chitin ***: Although species did not differ in the number of grit particles in their stomachs, we found that grit was mostly ingested by female individuals, with only one male of one species(Mexican Violetear) presenting grit in its stomach. We also found that female hummingbirds had grit in their stomachs during the rainy and the cold-dry season(June-February) but not during the warm-dry season(March-May). Our analyses revealed no relationship between the number of grit particles and the amount of ingested arthropods and arthropod chitin content. However,high grit consumption was related to wasp ingestion on Mexican ***: Our results indicate that grit is used mainly by female hummingbirds. The seasonal variation in the ingestion of grit by female individuals suggests that it can be used to meet mineral requirements related to breed-ing;how

关键词： Arthropod chitin content Arthropod digestion Breeding season Mineral nutritional requirements

Geochemical characteristics of natural gases and source rocks in Obayied sub-basin,north Western Desert,Egypt:implications for gas-source correlation

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Acta Geochimica 2023年第2期42卷 241-255页

作者： Mostafa Hassan Mahmoud Leila Mohammed Ahmed Ghalib Issa omar Hegab Geology Department Faculty of ScienceMansoura UniversityMansoura 35516Egypt Egyptian General Petroleum Corporation CairoEgypt

Western Desert represents a major oil and gas province in Egypt producing more than 50%of the country’s oil *** and gas blend occurs in most producing fields,however,the genetic link between gas and liquid hydrocarbon phases are not *** sub-basin in the Western Desert where oil and gas phases coexist in the Middle Jurassic sandstones of the Khatatba Formation provides an ideal place to investigate the link between oil and gas *** analyses on rock samples(Rock–Eval pyrolysis,vitrinite reflectance,R_(o))and gases(molecular and isotopic composition)were conducted in order to identify the genetic characteristics of the hydrocarbon phases ***-relevant parameters(Rock–Eval T_(max),vitrinite reflectance R_(o))elucidate that only Middle Jurassic Khatatba organofacies capable of generating wet and dry hydrocarbon ***,the enrichment of C_(7)normal alkanes,mono-branched alkanes relative to polybranched components in the Obayied gases reflect their generation via cracking of *** modelling results confirm gas generation through both primary and secondary ***,secondary cracking of liquid hydrocarbon phases is volumetrically more *** cracking of the Khatatba organofacies likely predate and catalyze the secondary cracking of the liquid phases and therefore the volume of generated gas increases incrementally eastward where both processes *** present study highlights the significant role of secondary cracking in the generation and accumulation of huge gas accumulations in the basins containing oil-prone source intervals.

关键词： Primary and secondary cracking Gas geochemistry Jurassic Khatatba Obayied Western Desert

Mixed phase sodium manganese oxide as cathode for enhanced aqueous zinc-ion storage

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Chinese Journal of Chemical Engineering 2020年第8期28卷 2214-2220页

作者： Xinyu Wang Xinghua Qin Qiongqiong Lu Mingming Han Ahmad omar Daria Mikhailova Institute of Materials and Technology Dalian Maritime UniversityDalian 116026China Leibniz Institute for Solid State and Materials Research(IFW)Dresden e.V. Helmholtzstraße 2001069 DresdenGermany School of Materials Science and Engineering Central South UniversityChangsha 410083China

Aqueous zinc-ion batteries have been regarded as a promising alternative to large-scale energy storage, due to associated low-cost, improved safety and environmental friendliness. However, a high-performance cathode material for both rate capability and specific capacity is still a challenge. One kind of the more promising candidates are sodium manganese oxide(NMO) materials, although they suffer from individual issues and need to be further improved. Herein, we present a novel mixed phase NMO material composed of nearly equal amounts of Na(0.55)Mn2O4 and Na(0.7)MnO(2.05). The structured configuration with particle size of 200–500 nm is found to be beneficial towards improving the ion diffusion rate during the charge/discharge process. Compared with Na(0.7)MnO(2.05) and Na(0.55)Mn2O4, the mixed phase NMO demonstrates an enhanced rate capability and excellent long-term cycling stability with a capacity retention of 83% after 800 cycles. More importantly, the system also delivers an impressive energy density and power density, as 378 W·h·kg^-1 at 68.7 W·kg^-1, or 172 W·h·kg^-1 at 1705 W·kg^-1. The superior electrochemical performance is ascribed to the fast Zn^2+ diffusion rate because of a large ratio of capacitive contribution(63.9% at 0.9 m V·s^-1). Thus, the mixed phase route provides a novel strategy to enhance electrochemical performance, enabling mixed phase NMO as very promising material towards large-scale energy-storage applications.

关键词： Aqueous zinc-ion battery Sodium manganese oxide Mixed phase High energy density

Laparoscopic celiac plexus ganglioneuroma resection: A video case report

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World Journal of Gastrointestinal Surgery 2019年第3期11卷 191-197页

作者： Pouya Hemmati omar Ghanem Juliane Bingener Department of Surgery Mayo Clinic General Surgery Mosaic Life Care

BACKGROUND Ganglioneuromas are mature, benign neurogenic tumors that arise from neural crest-derived cells. Given the rarity of these tumors and their often close proximity to major vessels, there is a paucity of reports in the literature of minimally invasive resections of ganglioneuromas near the celiac plexus. We report a case of laparoscopic resection of a retroperitoneal ganglioneuroma adhering to the portal vein and celiac *** SUMMARY A 27-year-old female was referred to our medical center with a symptomatic retroperitoneal mass. Using high quality preoperative imaging and biopsies, we confirmed the diagnosis of a 4 cm ganglioneuroma abutting the celiac axis, portal vein, and the caudate lobe of the liver. We elected for laparoscopic resection after careful preoperative planning and discussions with the patient. Laparoscopy enhanced visualization of the tumor and its relationships to surrounding vital structures for optimal dissection. Ultrasonic energy devices and adjusting liver retraction to allow for manipulation of the mass facilitated a safe and effective resection in a tight space. There were no operative complications and the patient was discharged home on postoperative day 1 with no residual symptoms upon follow-up. With sufficient experience in laparoscopic surgery and preoperative imaging and diagnostics, a minimally invasive approach for removing this celiac plexus ganglioneuroma was *** In carefully selected patients, laparoscopic ganglioneuroma resection is appropriate, reducing postoperative morbidity, hospital length of stay, and recovery time.

关键词： Ganglioneuroma Celiac plexus Laparoscopic surgery Case report

Galactagogue effects of Musa x paradisiaca flower extract on lactating rats

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Asian Pacific Journal of Tropical Medicine 2012年第11期5卷 882-886页

作者： Azizah Mahmood Muhammad Nor omar Nurziana Ngah Kulliyyah of Science International Islamic University Malaysia25200 Bandar Indera MahkotaKuantanPahangMalaysia Department of Food Technology Polytechnic of Sultan Haji Ahmad Shah25352 SemambuKuantanPahangMalaysia

Objective:To investigate the potential of Musa x paradisiaca(M.x paradisiaca)flower extracts in promoting milk production of lactating rats and its effects on growth of the suckling pups. Methods:Galactagogue activity was evaluated in terms of quantity of milk produced from the rats treated with petroleum ether,ethanol or water extracts of the *** rats(n=5) of Spraque Dawley with six pups each were administered with the extracts in the amount of 500 mg/kg body weight,while the control rats were given an equivalent amount of distilled *** rats were daily administered via oral feeding starting from Day 5 until Day 14 and the performance of milk production was measured along the experimental period by weight-suckle-weight method. Results were statistically analyzed using SPSS by means of ANOVA at 0.05 and was expressed as their mean±standard *** rates of pups’ growth were measured as the weight gain along the experimental ***:The rats treated with aqueous extract produced higher milk than control and ethanol *** extract was identified to increase milk production by 25%,while petroleum ether extract by 18%.The mean of yields produced by the rats during suckling period for aqueous,petroleum ether,ethanol and control were 4.62±2.45,4.37±1.93,3.65±1.89 and 3.69±1.79,*** rates of pups for the rats treated with control,aqueous, ethanol extract and petroleum ether were(1.85±0.49),(1.78±0.56),(1.65±0.46)and(1.56±0.42) g/pup, ***:The present study reveals the potential of M.x paradisiaca flower to enhance milk production of nursing mothers which could be exploited for commercialization of the isolated extract.

关键词： Banana flower Musa x paradisiacal Galactagogue Lactating rats phytochemicals

Deep Forest-Based Fall Detection in Internet of Medical Things Environment

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Computer Systems Science & Engineering 2023年第6期45卷 2377-2389页

作者： Mohamed Esmail Karar omar Reyad Hazem Ibrahim Shehata College of Computing and Information Technology Shaqra UniversityP.O.Box 33Shaqra11961Saudi Arabia Department of Industrial Electronics and Control Engineering Faculty of Electronic EngineeringMenoufia UniversityMenouf32952Egypt Computer Science Department Faculty of Computers and Artificial IntelligenceSohag UniversitySohag82524Egypt Department of Computer and Systems Engineering Faculty of EngineeringZagazig UniversityZagazig44519Egypt

This article introduces a new medical internet of things(IoT)framework for intelligent fall detection system of senior people based on our proposed deep forest *** cascade multi-layer structure of deep forest classifier allows to generate new features at each level with minimal hyperparameters compared to deep neural ***,the optimal number of the deep forest layers is automatically estimated based on the early stopping criteria of validation accuracy value at each generated *** suggested forest classifier was successfully tested and evaluated using a public SmartFall dataset,which is acquired from three-axis accelerometer in a *** includes 92781 training samples and 91025 testing samples with two labeled classes,namely non-fall and *** results of our deep forest classifier demonstrated a superior performance with the best accuracy score of 98.0%compared to three machine learning models,i.e.,K-nearest neighbors,decision trees and traditional random forest,and two deep learning models,which are dense neural networks and convolutional neural *** considering security and privacy aspects in the future work,our proposed medical IoT framework for fall detection of old people is valid for real-time healthcare application deployment.

关键词： Elderly population fall detection wireless sensor networks internet of medical things deep forest

Modeling Date Palm Trunk Fibers (DPTF) Packed Bed Adsorption Performances for Cadmium Removal from Aqueous Wastewater

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Fluid Dynamics & Materials Processing 2023年第6期19卷 1535-1549页

作者： Ahmad S.Awad Banan Hudaib Waid omar Mechanical Engineering Department Faculty of Engineering TechnologyAl-Balqa Applied UniversityAmman11134Jordan Chemical Engineering Department Faculty of Engineering TechnologyAl-Balqa Applied UniversityAmman11134Jordan

In this study,the potential of a low-cost bio-adsorbent,taken directly from Date Palm Trunk Fibers(DPTF)agricultural wastes,for cadmium ions removal from wastewaters is *** performances of this adsorbent are evaluated by building breakthrough curves at different bed heights and flow rates while keeping other parameters,such as the initial feed concentration,pH,and particle size,*** results indicate that the maximum cadmium adsorption capacity of DTPF can be obtained from the Thomas model as 51.5 mg/g with the most extended mass transfer zone of 83 min at the lowest flow rate at 5 ml/*** saturation concentrations(NO)and the rate constant(kab)obtained from the BDST(bed depth service time)model are 7022.16 mg/l and 0.0536 l/***,*** the Yon-Nelsen Model,it is found that operating at a lower flow rate leads to a larger value of the elapsed needed time to reach a 50%*** Wolborska model indicates that the bed capacity increases with decreasing the flow rate,and the adsorbent can achieve a greater external mass transfer kinetic coefficient(2.271/min)at a higher flow rate.

关键词： Cadmium ions adsorption fixed bed biodorbent pollutant date palm trunk fibers wastewater treatment breakthrough curves modeling