检索结果-南通市图书馆

An energetic nano-fiber composite based on polystyrene and 1,3,5-trinitro-1,3,5-triazinane fabricated via electrospinning technique

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2023年第9期27卷 1-8页

作者： Mahmoud Abdelhafiz ahmed K.Hussein Waleed F.Khalil ahmed Elbeih Military TechnicalCollege(MTC) KobryElkobbahCairoEgypt Safety FuelCycleDepartment NRSRCEgyptianAtomicEnergyAuthority(EAEA)CairoEgypt

Electrospinning is a simple technique used to fabricate polymeric nano-fibrous *** nano-fibers have found a wide range of valuable applications in the biomedical ***,it has not been utilized with solid high explosives ***,the electrospinning technique has been used to fabricate polystyrene(PS)/1,3,5-trinitro-1,3,5-triazinane(RDX)composite *** governed electrospinning parameters,voltage,distance from the collector,flow rate,mandrel rotating speed,time,and solution concentration,that greatly affect the morphology of the obtained nanofibers were *** fabricated PS/RDX nano-fibers were characterized using scanning electron microscopy(SEM),X-ray diffractometer(XRD),and Fourier Transform Infrared(FTIR)*** impact and friction sensitivities of PS/RDX were also *** thermal behavior of the prepared composite and the pure materials were studied by the thermal gravimetric analysis technique(TGA).SEM results proved the fabrication of PS/RDX fibers in the nano-size via *** spectroscopy confirmed the existence of the characteristic functional groups of both PS and RDX in the composite *** sharp peaks showed the conversion of amorphous PS into crystalline shape via electrospinning and also confirmed the formation of PS/RDX *** PS fibers absorbed the heat and increased the onset decomposition of the pure RDX from 181.5 to 200.7℃in the case of PS/RDX ***,PS/RDX nano-fibers showed the relatively low impact and friction sensitivities of 100 J and 360 N *** results could introduce PS/RDX nanofibrous composite in the field of explosives detection with high levels of safety.

关键词： Electrospinning Nano-fibers 1,3,5-Trinitro-1,3,5-triazinane(RDX) Polystyrene(PS) Sensitivity

Association between direct-acting antiviral agents in hepatitis C virus treatment and hepatocellular carcinoma occurrence and recurrence:The endless debate

在线全文

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2022年第6期10卷 1764-1774页

作者： ahmed Kamal ahmed Elsheaita Mahmoud Abdelnabi Internal Medicine Department Faculty of Medicine Alexandria UniversityAlexandria 21131Egypt Clinical and Experimental Internal Medicine Department Medical Research Institute Alexandria UniversityAlexandria 21561Egypt Internal Medicine Department Texas Tech University Health Science CenterLubbockTX 79430United States

Since direct-acting antiviral agents(DAAs)have been introduced into hepatitis C virus treatment,the sustained viral response(SVR)rate has significantly increased to more than 95%.Scientific evidence supports the idea that SVR after interferon therapy has beneficial effects related to cirrhosis progression,resulting in a reduction in the incidence of hepatocellular carcinoma(HCC).However,a significant debate exists related to DAA impact on HCC *** reviewed the current literature highlighting the controversial data related to DAA association with de novo HCC occurrence or recurrence and possible pathophysiology of HCC related to *** a review of the published literature,we believe that the current evidence does not confirm or repudiate a higher rate of de novo HCC occurrence or recurrence related to DAA *** trials are needed to determine if there is an association between HCC occurrence or recurrence and DAA or if it is related to preexisting liver cirrhosis.

关键词： Hepatitis C virus Sustained virologic response Direct-acting antiviral drugs Hepatocellular carcinoma Liver cirrhosis

Price Prediction of Seasonal Items Using Time Series Analysis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computer Systems Science & Engineering 2023年第7期46卷 445-460页

作者： ahmed Salah Mahmoud Bekhit Esraa Eldesouky ahmed Ali ahmed Fathalla Faculty of Computers and Informatics Zagazig UniversitySharkeya44523Egypt Information Technology Department the University of Technology and Applied SciencesIbriOman School of Electrical and Data Engineering University of Technology SydneySydney2007Australia College of Computer Engineering and Sciences Prince Sattam Bin Abdulaziz UniversityAl-Kharj11942Saudi Arabia Computer Science Department Faculty of Computers and InformaticsSuez Canal UniversityIsmailia41522Egypt Higher Future Institute for Specialized Technological Studies Cairo3044Egypt Department of Mathematics Faculty of ScienceSuez Canal UniversityIsmailia41522Egypt

The price prediction task is a well-studied problem due to its impact on the business *** are several research studies that have been conducted to predict the future price of items by capturing the patterns of price change,but there is very limited work to study the price prediction of seasonal goods(e.g.,Christmas gifts).Seasonal items’prices have different patterns than normal items;this can be linked to the offers and discounted prices of seasonal *** lack of research studies motivates the current work to investigate the problem of seasonal items’prices as a time series *** proposed utilizing two different approaches to address this problem,namely,1)machine learning(ML)-based models and 2)deep learning(DL)-based ***,this research tuned a set of well-known predictive models on a real-life *** models are ensemble learning-based models,random forest,Ridge,Lasso,and Linear ***,two new DL architectures based on gated recurrent unit(GRU)and long short-term memory(LSTM)models are ***,the performance of the utilized ensemble learning and classic ML models are compared against the proposed two DL architectures on different accuracy metrics,where the evaluation includes both numerical and visual comparisons of the examined *** obtained results show that the ensemble learning models outperformed the classic machine learning-based models(e.g.,linear regression and random forest)and the DL-based models.

关键词： Deep learning price prediction seasonal goods time series analysis

Wireless Network Requirements and Solutions for the Future Circular Collider:A Hostile Indoor Environment

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

China Communications 2021年第10期18卷 193-203页

作者： ahmed Bannour Yichuang Sun University of Carthage InnovCom Laboratory Higher School of Communications of TunisSup’ComCite Technologique des´Communications Route de Raoued Km 352083 El Ghazala Ariana Tunisie TunisTunisia University of Hertfordshire School of Engineering and TechnologyHatfieldHertsAL109ABUK

The European organization for nuclear research(CERN)is planning a high performance particle collider by 2050,which will update the currently used Large Hadron Collider(LHC).The design of the new experiment facility includes the definition of a suitable communication infrastructure to support the future needs of *** huge amount of data collected by the measurement devices call for a data rate of at least 1 Gb/s per node,while the need of timely control of instruments requires a low latency of the order of 0.01μ***,the main tunnel will be 100 km long,and will need appropriate coverage for voice and data traffic,in a special underground environment subject also to strong *** voice,data and video transmission in a tunnel of this length is necessary to ensure timely and localized intervention,reducing access *** addition,using wireless communication for voice,control and data acquisition of accelerator technical systems could lead to a significant reduction in cabling costs,installation times and maintenance *** communication infrastructure of the Future Circular Collider(FCC)tunnel must be able to circumvent the problems of radioactivity,omnipresent in the *** technologies transceivers cannot transmit in such a severely radioactive *** is due to the immediate destruction of any active or passive equipment by *** scope of this paper is to determine the feasibility of robust wireless transmission in an underground radioactive tunnel *** network infrastructure design to meet the demand will be introduced,and the performance of different wireless technologies will be evaluated.

关键词： future circular collider LHC tunnel low latency harsh indoor wireless communications

Algebraic Characterization of SSC of Uni-Cyclic Multigraphs

在线全文

学校读者我要写书评

暂无评论

Algebra Colloquium 2023年第2期30卷 325-338页

作者： Imran ahmed Shahid Muhmood Department of Mathematics COMSATS University Islamabad Lahore CampusLahorePakistan

We introduce first the spanning simplicial complex(SSC)of a multigraph g,which gives a generalization of the SSC associated with a simple graph *** properties are discussed for the SSC of a family of uni-cyclic multigraphs U_(n)^(r),m with n edges including r multiple edges within and outside the cycle of length m,which are then used to compute the f-vector and Hilbert series of face ring k[△s(U_(n)^(r),m)]for the SSC △s(U_(n)^(r),m)(un,m).Moreover,we find the associated primes of the facet ideal I_(F)(△s(U_(n)^(r),m).Finally,we device a formula for homology groups of △s(U_(n)^(r),m) prove that the SsC of a family of uni-cyclic multigraphs is Cohen-Macaulay.

关键词： simplicial complexes spanning trees Hilbert series vertex covers Betti numbers

A Note on z-Ideals and z°-Ideals of the Formal Power Series Rings and Polynomial Rings in an Infinite Set of Indeterminates

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Algebra Colloquium 2020年第3期27卷 495-508页

作者： ahmed Maatallah Ali Benhissi Faculty of Sciences of Monastir MonastirTunisia

Let A be a *** this paper we generalize some results introduced by Aliabad and *** give a relation bet ween the z-ideals of A and t hose of the formal power series rings in an infinite set of indetermiiiates over *** A[[Xa]]3 and its subrings A[[X_(A)]]_(1),A[[X_(A)]]_(2),and A[[X_(A)]]_(α),where a is an infinite cardinal *** fact,a z-ideal of the rings defined above is of the form I+(X_(A))i,where i=1,2,3 or an infinite cardinal number and I is a z-ideal of *** addition,we prove that the same condition given by Aliabad and Mohamadian can be used to get a relation between the minimal prime ideals of the ring of the formal power series in an infinite set of indeterminates and those of the ring of *** a natural result,we get a relation between the z°-ideals of the formal power series ring in an infinite set of indeterminates and those of the ring of coefficients.

关键词： z-ideal z°-ideal formal power series ring polynomial ring infinite set of inde terminates

Modeling severities of motorcycle crashes using random parameters

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Traffic and Transportation Engineering(English Edition) 2021年第2期8卷 225-236页

作者： ahmed Farid Khaled Ksaibati Wyoming Technology Transfer Center Department of Civil and Architectural EngineeringUniversity of WyomingLaramieWY 82071USA

One of the critical areas of road safety is motorcycle safety. Motorcyclists are more vulnerable to injuries than occupants of other motor vehicles when involved in *** have studied the relationships between motorcycle crash severity and crash contributing factors. They are crash characteristics, roadway geometric design features,traffic characteristics, socio-demographics and environmental conditions. However, few researchers considered unobserved heterogeneity effects when modeling motorcycle crash injury severities, let alone interaction effects. In this research, motorcycle crashes in Wyoming that occurred from 2008 to 2017 were analyzed. Specifically, the injury severities of single motorcycle crashes and multiple vehicle crashes involving motorcycles were modeled. The response was whether the motorcycle crash incurred an incapacitating injury or fatality or not. The binary logistic regression and mixed binary logistic regression modeling structures were implemented. The mixed models revealed effects that otherwise would have been undisclosed in the binary logistic regression models’ results. According to the results of single motorcycle crashes, the majority of motorcycle-animal crashes and of motorcycle-barrier crashes were likely to be severe relative to other single motorcycle crashes. It was also found that horizontal curves increased the risk of severe *** riders were found to be less at risk of being gravely injured in single motorcycle crashes than older riders as well. Furthermore, riding under the influence and high posted speed limits increased the odds of severe crashes regardless of whether the crashes were single motorcycle crashes or multiple vehicle crashes involving motorcycles. Additionally,the mixed models uncovered interaction effects and unobserved effects pertaining to speed limits.

关键词： Transportation engineering Motorcycle safety Injury severity Logistic regression Random parameters

Improving of photocatalytic activity of barium ferrate via bismuth and copper co-doping for degradation of paracetamol under visible light irradiation

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2022年第2期34卷 331-342页

作者： Hussien ahmed Abbas Rabab ahmed Nasr Rose-Noelle Vannier Tarek Samir Jamil Inorganic Chemistry Department National Research CentreCairo 12622Egypt Water Pollution Control Department National Research CenterCairo 12622Egypt Univ.Lille CNRSCentrale LilleENSCLUniv.ArtoisUMR 8181Unite de Catalyse et Chimie du Solide(UCCS)Lille 59000France

Nanosized Ba_(1-x)Bi_(x)Fe_(1-x)Cu_(x)O_(3)(12–50 nm)with x values of 0,0.01,0.05,and 0.1 system was prepared using the Pechini ***,morphological,surface and optical characterizations were performed for the prepared *** phase was the predominant phase for the undoped BaFeO_(3)and Bi and Cu co-doped BaFeO_(3)*** phases of monoclinic Ba_(2)Fe_(2)O_(5),orthorhombic BaFe_(2)O_(4)and orthorhombic BaCO_(3)were identified for all the prepared ***_(0.95)Bi_(0.05)Fe_(0.95)Cu_(0.05)O_(3)sample has the lowest band gap(2.43 e V).98.1%paracetamol removal was achieved with 0.75 g/L of Ba_(0.95)Bi_(0.05)Fe_(0.95)Cu_(0.05)O_(3)at pH9 after 120 *** paracetamol degradation follows the pseudo first-order ***·is the main oxidative species responsible for the paracetamol *** chromatography–mass spectrometry(GC–MS)analysis was performed at the end of the photocatalytic degradation experiment under optimum operating condition using Ba_(0.95)Bi_(0.05)Fe_(0.95)Cu_(0.05)O_(3)to explain the reaction mechanism and identify the intermediate by-products which is confirmed by ultraviolet/visible(UV/Vis)spectroscopy study at different reaction times.

关键词： Ba_(1-x)Bi_(x)Fe_(1-x)Cu_(x)O_(3) Photocatalytic degradation Nanomaterials Paracetamol

Study of scalar particles through the Klein–Gordon equation under rainbow gravity effects in Bonnor–Melvin-Lambda space-time

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2024年第4期76卷 113-125页

作者： Faizuddin ahmed Abdelmalek Bouzenada Department of Physics University of Science&Technology MeghalayaRi-Bhoi793101India Laboratory of theoretical and applied Physics Echahid Cheikh Larbi Tebessi UniversityAlgeria

In our investigation,we explore the quantum dynamics of charge-free scalar particles through the Klein–Gordon equation within the framework of rainbow gravity,considering the Bonnor–Melvin-Lambda(BML)space-time *** BML solution is characterized by the magnetic field strength along the axis of the symmetry direction which is related to the cosmological constantΛand the topological parameterαof the *** behavior of charge-free scalar particles described by the Klein–Gordon equation is investigated,utilizing two sets of rainbow functions:(i)f(χ)=■,h(χ)=1 and(ii)f(χ)=1,h(χ)=1+βХ/*** 0<(Х=■)≤1 with E representing the particle's energy,Ep is the Planck's energy,andβis the rainbow *** obtain the approximate analytical solutions for the scalar particles and conduct a thorough analysis of the obtained ***,we study the quantum dynamics of quantum oscillator fields within this BML space-time,employing the Klein–Gordon *** also,we choose the same sets of rainbow functions and obtain the approximate eigenvalue solution for the oscillator ***,we demonstrate that the relativistic approximate energy profiles of charge-free scalar particles and oscillator fields get influenced by the topology of the geometry and the cosmological ***,we show that the energy profiles of scalar particles receive modifications from the rainbow parameter and the quantum oscillator fields by both the rainbow parameter and the frequency of oscillation.

关键词： quantum fields in curved space-time relativistic wave equations solutions of wave equations bound-state special functions