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Fabrication of PMMA nanocomposite biomaterials reinforced by cellulose nanocrystals extracted from rice husk for dental applications

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Friction 2024年第12期12卷 2808-2825页

作者： Ahmed FOULY Walid M.DAOUsH Hesham I.ELQADY hany s.abdo Mechanical Engineering Department College of EngineeringKing Saud UniversityRiyadh 11421Saudi Arabia The King salman Center for Disability Research Riyadh 11421Saudi Arabia Department of Production Engineering and Mechanical Design Faculty of EngineeringMinia UniversityMinia 61519Egypt Department of Chemistry College of ScienceImam Mohammad Ibn Saud Islamic University(IMSIU)Riyadh 11623Saudi Arabia Faculty of Technology and Education Helwan UniversityCairo 11281Egypt Faculty of Engineering Aswan UniversityAswan 81528Egypt Center of Excellence for Research in Engineering Materials(CEREM) King Saud UniversityRiyadh 11421Saudi Arabia Mechanical Design and Materials Department Faculty of Energy EngineeringAswan UniversityAswan 81521Egypt

The primary objective of global studies is to develop the properties and durability of polymers for various *** it comes to dental disability,denture base materials must have sufficient mechanical and tribological performance in order to withstand the forces experienced in the *** work aims to investigate the effects of the addition of low content of cellulose nanocrystals(CNC)on the mechanical and tribological performance of the polymethyl methacrylate(PMMA)*** weight percent of CNC(0,0.2,0.4,0.6,and 0.8 wt%)were added to the PMMA matrix followed by ball milling to evenly distribute the nanoparticles reinforced phase in the matrix *** findings emphasize the significant impact of CNC integration on the performance of PMMA *** increasing the content of the CNC nanoparticles,the mechanical properties of PMMA were *** addition,the tribological outcomes demonstrated a significant reduction in the friction coefficient besides an enhancement in the wear resistance as the weight percentage of nanoparticles *** surface of the worn samples was investigated by utilizing sEM to identify the wear mechanisms corresponding to the different *** addition,a finite elment model(FEM)was developed to ascertain the thickness of the worn layer and the generated stressed on the surfaces of the nanocomposite throughout the friction process.

关键词： polymethyl methacrylate nanocomposite cellulose nanocrystals denture materials rice husk polymethyl methacrylate(PMMA) wear resistance

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Hyperspectral imaging and remote trace detection of cis-1,3,4,6-tetranitrooctahydroimidazo-[4,5 d]imidazole(BCHMX)compared with traditional explosives using laser induced fluorescence

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Defence Technology（防务技术） 2021年第5期17卷 1609-1616页

作者： hany s.Ayoub Ashraf F.El-sherif Ahmed Elbeih Department of Physics Faculty of ScienceCairo UniversityEgypt Laser Photonics Research Center Engineering Physics DepartmentMilitary Technical CollegeCairoEgypt Explosives Department Military Technical CollegeKobry ElkobbahCairoEgypt

cis-1,3,4,6-Tetranitrooctahydroimidazo-[4,5 d]imidazole(BCHMX)is an advanced energetic compound that expected to spread worldwide in the near ***,no approved remote detection methods were reported in current literature for this material,we performed hyper-spectral imaging and laser induced fluorescence(LIF)to a BCHMX sample under low laser fluence for determining the optimum laser wavelength used in any future BCHMX-LIF based remote detection *** this purpose,an experimental setup consisted of a sun spectrum lamp and hyper-spectral camera was built to illuminate and image white powder samples of BCHMX in comparison with the traditional explosives,HMX(1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane),RDX(1,3,5-trinitro-1,3,5-triazacyclohexane),PETN(2,2-Bis[(nitroxy)methyl]propane-1,3-diyldinitrate).The imaging reveals strong BCHMX sample absorption contrast among other samples at wavelength ranging from 400 to 410 *** light source was replaced by a 405 nm laser diode illuminator,a strong BCHMX sample LIF at the spectral range from 425 to 700 nm was observed under low laser fluence condition of 0.1 mJ/cm^(2).Finally,we demonstrated successfully the ability of the 405 nm LIF and the hyperspectral imaging technique to detect finger print traces of BCHMX on white cellulose fabric from a distance of 15 m and a detection limit of 1 mg/cm^(2).

关键词： Hyperspectral imaging Remote trace detection BCHMX Laser induced fluorescence

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Reduced graphene oxide supersonically sprayed on wearable fabric and decorated with iron oxide for supercapacitor applications

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Journal of Materials science & Technology 2021年第23期82卷 47-56页

作者： Ali Aldalbahi Edmund samuel Bander s.Alotaibi hany El-Hamshary sam s.Yoon Department of Chemistry College of ScienceKing Saud UniversityRiyadh11451Saudi Arabia school of Mechanical Engineering Korea UniversitySeoul136-713Republic of Korea

We demonstrate the fabrication of wearable supercapacitor *** electrodes were applied to wearable fabric by supersonically spraying the fabric with reduced graphene oxide(r GO)followed by decoration with iron oxide(Fe_(2)O_(3))nanoparticles via a hydrothermal *** integration of iron oxide with r GO flakes on wearable fabric demonstrates immense potential for applications in high-energystorage *** synergetic impact of the intermingled r GO flakes and Fe_(2)O_(3) nanoparticles enhances the charge transport within the composite electrode,ultimately improving the overall electrochemical *** advantage of the porous nature of the fabric,electrolyte diffusion into the active r GO and Fe_(2)O_(3) materials was significantly enhanced and subsequently increased the electrochemical interfacial *** effect of the Fe_(2)O_(3) concentration on the overall electrochemical performance was *** optimal composition yields a specific capacitance of 360 F g^(-1) at a current density of 1 Ag^(-1) with a capacitance retention rate of 89%after 8500 galvanostatic cycles,confirming the long-term stability of the Fe_(2)O_(3)/r GO fabric electrode.

关键词： supersonic spraying Conductive textile Wearable energy devices Reduced graphene oxide Iron oxide supercapacitor

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Efficient Channel Estimation Techniques for MIMO systems with 1-Bit ADC

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China Communications 2020年第5期17卷 50-64页

作者： hany sHussein shaimaa Hussein Ehab Mahmoud Mohamed Electrical Engineering Dept. College of EngineeringKing Khalid UniversityAbha 61411King of Saudi Arabia Electrical Engineering Dept. Faculty of EngineeringAswan UniversityAswan 81542Egypt Electrical Engineering Dept. College of EngineeringPrince Sattam Bin Abdulaziz UniversityWadi Addwasir 11991King of Saudi Arabia

With a low resolution 1-bit ADC on its receiver(RX) side, MIMO with 1-bit ADC took a considerable step in the fulfillment of the hardware complexity constrains of the internet of things(IoT) PHY layer design. However, applying 1-bit ADC at MIMO RX results in severe nonlinear quantization error. By which, almost all received signal amplitude information is completely distorted. Thus, MIMO channel estimation is considered as a major barrier towards practical realization of 1-bit ADC MIMO system. In this paper, two efficient sparsity-based channel estimation techniques are proposed for 1-bit ADC MIMO systems, namely the low complexity sparsity-based channel estimation(LCsCE), and the iterative adaptive sparsity channel estimation(IAsCE). In these techniques, the sparsity of the 1-bit ADC MIMO channel is exploited to propose a new adaptive and iterative compressive sensing(Cs) recovery algorithm to handle the 1-bit ADC quantization effect. The proposed algorithms are tested with the state-of-the-art 1-bit ADC MIMO constant envelope modulation(MIMO-CEM). The 1-bit ADC MIMO-CEM system is chosen as it fulfills both energy and hardware complexity constraints of the IoT PHY layer. simulation results reveal the high effectiveness of the proposed algorithms in terms of spectral efficiency(sE) and computational complexity. The proposed LCsCE reduces the computational complexity of the 1-bit ADC MIMO-CEM channel estimation by 86%, while the IAsCE reduces it by 96% compared to the recent techniques of MIMO-CEM channel estimation. Moreover, the proposed LCsCE and IAsCE improve the spectrum efficiency by 76 % and 73 %, respectively, compared to the recent techniques.

关键词： channel estimation 1-bit ADC MIMO sparsity recovery compressive sensing Internet of things

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Can lanthanum doping enhance catalytic performance of silver in direct propylene epoxidation over NaMoAg/siO_2?

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Journal of Rare Earths 2019年第5期37卷 500-507页

作者： hany M.Abdel Dayem shar s.Al-shihry salah A.Hassan Chemistry Department Faculty of Science Ain Shams University Chemistry Department College of Science King Faisal University

In the attempt to reduce surface free energy of silica to improve interaction of silica with silver, silica was doped by different amounts of low surface energy lanthanum, La_2O_3, through impregnation. The doped and undoped silica were used as supports for preparation of Na/Ag/Mo/La_2O_3-siO_2 catalysts. Catalytic performances of the catalysts were evaluated in direct epoxidation of propylene(DPO) using molecular oxygen under atmospheric pressure and without adding hydrogen. Adding 5 wt%La to the Na/Ag/Mo/siO_2 catalyst improves both the catalysts electivity in DPO and its stability over 20h of *** characterization results show that La_2O_3 species interact strongly with silver particles on the silica surface which result in significant improvement in the dispersion profile of silver and marked decrease in the size of silver nanoparticles(AgNPs). The estimated mean diameter of AgNPs is ca. 4.0 nm in Na/Ag/Mo/5 wt%La_2O_3-siO_2, which is smaller than that(53.9 nm) found in Na/Ag/siO_2. The presence of subnanometer AgNPs on Ag/La_2O_3-siO_2 prior addition of MoO_3 and NaCl to the sample can enhance the mutual electronic synergism between Ag, MoO_3 and Na for selective production of propylene oxide.

关键词： Direct epoxidation Propylene Gas phase silver subnanometer Lanthanum

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Discontinuous phenomena in bioreactor and membrane reactor systems

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International Journal of Biomathematics 2019年第4期12卷 255-276页

作者： hany A.Hosham Department of Mathematics Faculty of Science Taibah University Yanbu Saudi Arabia Department of Mathematics Faculty of Science Al-Azhar University Assiut 71524 Egypt

In this work, we analyze the existence of discontinuous bifurcation and stability issues in discontinuous flow of bioreactor and membrane reactor models with or without recycle. The reaction is assumed to be governed by certain types of discontinuities in Monod growth kinetics curve leading to discontinuous dynamical system. The criteria for the existence and stability of steady-states of these models are established. More generally, our analysis highlights the presence of several types of bifurcation depending upon the effect of the dilution factor (residence time), biomass concentration and solid-liquid-gas separator efficiency. As well, we present bifurcation conditions defining the dynamics near steady-state branches on the border, providing a possible framework for existing of saddle-node, nonsmooth fold, persistence and grazing-sliding scenarios. It is shown that the critical values of residence time dependence upon recycle ratio, decay rate and existence of discontinuity surface. Further, the performance of the reactor at largest residence times will be discussed. In addition, numerical simulations to illustrate and confirm the results will be carried out.

关键词： Discontinuous dynamical system discontinuous bifurcation saddle-nodegrazing-sliding bifurcation bioreactor and membrane reactor models

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Interactive platform for peer review:A proposal to improve the current peer review system

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World Journal of Clinical Cases 2021年第6期9卷 1247-1250页

作者： sameh hany Emile General surgery Department Mansoura University HospitalsMansoura UniversityMansoura 35516Egypt

Peer review is the cornerstone in scientific *** peer review has paramount importance in ensuring the quality of the published literature,it still has a number of *** present manuscript proposes a new method to improve the current peer review system by providing an interactive,dynamic platform that allows direct,anonymous interaction between the authors of submitted manuscripts and the *** real-time interaction may help eliminate any problems related to misunderstanding or misinterpretation of the reviewer’s comments or the authors’response,and would save time while keeping the identity of both parties anonymous.

关键词： Peer Review Interactive Proposal system Improve

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Porosity,cracks,and mechanical properties of additively manufactured tooling alloys:a review

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Advances in Manufacturing 2022年第2期10卷 175-204页

作者： Prveen Bidare Amaia Jimenez hany Hassanin Khamis Essa school of Mechanical Engineering University of BirminghamBirminghamUK TECNUN Escuela de Ingenieria Universidad de NavarraManuel de Lardizabal 15San Sebastian20018Spain school of Engineering Technologyand DesignCanterbury Christ Church UniversityCanterbury CT11QUUK

Additive manufacturing(AM)technologies are currently employed for the manufacturing of completely functional parts and have gained the attention of hightechnology industries such as the aerospace,automotive,and biomedical *** is mainly due to their advantages in terms of low material waste and high productivity,particularly owing to the flexibility in the geometries that can be *** the tooling industry,specifically the manufacturing of dies and molds,AM technologies enable the generation of complex shapes,internal cooling channels,the repair of damaged dies and molds,and an improved performance of dies and molds employing ***,a reviewof AM processes and materials applied in the tooling industry for the generation of dies and molds is *** technologies used for tooling applications and the characteristics of the materials employed in this industry are first *** addition,the most relevant state-of-the-art approaches are analyzed with respect to the process parameters and microstructural and mechanical properties in the processing of high-performance tooling materials used in AM ***,studies on the AM of ferrous(maraging steels and H13 steel alloy)and non-ferrous(stellite alloys and WC alloys)tooling alloys are also analyzed.

关键词： Additive manufacturing(AM) Tooling alloys super alloys Hybrid manufacturing Post processing

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HDec-POsMDPs MRs Exploration and Fire searching Based on IoT Cloud Robotics

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International Journal of Automation and computing 2020年第3期17卷 364-377页

作者： Ayman El shenawy Khalil Mohamed hany Harb systems and Computers Engineering Department Faculty of EngineeringAl-Azhar UniversityCairo 11751Egypt Information Technology College Misr University for Science and Technology(MUST)Cairo 77Egypt

The multi-robot systems(MRs)exploration and fire searching problem is an important application of mobile robots which require massive computation capability that exceeds the ability of traditional MRs′*** paper propose a cloud-based hybrid decentralized partially observable semi-Markov decision process(HDec-POsMDPs)*** proposed model is implemented for MRs exploration and fire searching application based on the Internet of things(IoT)cloud robotics *** this implementation the heavy and expensive computational tasks are offloaded to the cloud *** proposed model achieves a significant improvement in the computation burden of the whole task relative to a traditional *** proposed model is applied to explore and search for fire objects in an unknown environment;using different sets of robots *** preliminary evaluation of this implementation demonstrates that as the parallelism of computational instances increase the delay of new actuation commands which will be decreased,the mean time of task completion is decreased,the number of turns in the path from the start pose cells to the target cells is minimized and the energy consumption for each robot is reduced.

关键词： Multi-robot systems hybrid decentralized partially observable semi-Markov decision process(HDec-POsMDPs) multi-robot systems(MRs)exploration and fire searching cloud robotics cloud computing

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Rare earth oxides doped NiO/γ-Al_2O_3 catalyst for oxidative dehydrogenation of cyclohexane

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Journal of Rare Earths 2015年第6期33卷 611-618页

作者： hany M.AbdelD ayem M.Faiz Hesham s.Abdel-samad salah A.Hassan Center of Research Excellence in Petroleum Refining & Petrochemicals (CoR E-PRP) King Fahd University of Petroleum & Minerals Chemistry Department College of Science King Faisal University Chemistry Department Faculty of Science Ain Shams University surface science Laboratory Physics Department King Fahd University of Petroleum &Minerals Department of Basic sciences and Technology Community College Taibah University

The effect of rare earth oxides （RE=Ce, La, Gd, and Dy） doping of alumina support in NiO/7-A1203 system was investi- gated on its catalytic performance in oxidative dehydrogenation （ODH） of cyclohexane. The physicochemical properties of various samples were followed up through N2 physisorption, temperature programmed reduction （H2-TPR）, X-ray diffraction （XRD）, X-ray photoelectron spectroscopy （XPs） and potentiometric acid-base titration techniques. In the parent NiO/y-A1203 catalyst, Ni species were found to be strongly interacted with alumina surface. Addition of rare earth dopants to ）＇-A1203 in the catalyst system affected the nickel-alumina interaction and resulted in significant modifications in the catalytic performances in the ODH reaction. The results re- vealed the beneficial role of both La203 and Gd2Os doping in enhancing the ODH catalytic activity and selectivity to cyclohexene. H2-TPR and XPs results indicated that majority of Ni species in NiO/La203 modified T-A1203 were more weakly interacted with La203 and alumina whereas both NiO like species and nickel aluminate were present on the surface. Doping with cerium or dyspro- sium increased the nickel-support interaction and led to a decrease in surface nickel concentration. In case of doping with Ce, surface concentration of cerium oxide was higher than those of the other RE oxides; the doped catalyst reached its steady state activity faster than the other catalysts. The acid-base results suggested that RE metals were interacted most likely with acidic surface hydroxyl groups. The degree of nickel-alumina interaction decreased in the following order： LaAI〉GdAI〉CeAI〉DyA1.

关键词： nickel oxide rare-earth oxides doping Ni-A1203 interaction surface acidity oxidative dehydrogenation cyclohexane rare earths

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