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Hilfer fractional neutral stochastic partial differential equations with delay driven by Rosenblatt process

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Journal of Control and Decision 2022年第2期9卷 226-243页

作者： hamdy m.ahmed Higher Institute of Engineering El-Shorouk AcademyEI-Shorouk CityCairoEgypt

This manuscript is mainly focusing on the approximate controllability and the null controllability for fractional neutral stochastic partial differential equations with delay driven by Rosenblatt *** discuss the sufficient conditions for approximate controllability and null controllability for Hilfer fractional neutral stochastic partial differential equations driven by Rosenblatt ***,we provide two examples to verify the obtained results.

关键词： Hilfer fractional neutral stochastic integro-differential systems approximate controllability null controllability Rosenblatt process

Assessment of clay stiffness and strength parameters using index properties

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Journal of Rock mechanics and Geotechnical Engineering 2018年第3期10卷 579-593页

作者： Sayed m.ahmed Structural Engineering Department Ain Shams University

A new approach is developed to determine the shear wave velocity in saturated soft to firm clays using measurements of the liquid limit, plastic limit, and natural water content with depth. The shear wave velocity is assessed using the site-specific variation of the natural water content with the effective mean stress. Subsequently, an iterative process is envisaged to obtain the clay stiffness and strength *** at-rest earth pressure coefficient, as well as bearing capacity factor and rigidity index related to the cone penetration test, is also acquired from the analyses. Comparisons are presented between the measured clay parameters and the results of corresponding analyses in five different case studies. It is demonstrated that the presented approach can provide acceptable estimates of saturated clay stiffness and strength parameters. One of the main privileges of the presented methodology is the site-specific procedure developed based on the relationships between clay strength and stiffness parameters, rather than adopting direct correlations. Despite of the utilized iterative processes, the presented approach can be easily implemented using a simple spreadsheet, benefiting both geotechnical researchers and practitioners.

关键词： Soft to firm clays Atterberg limits Shear wave velocity Small-strain shear modulus Constrained modulus Undrained shear strength Effective friction angle Cone penetration test

Nanosecond pulse and dual-wavelength Q-switched 1.5 μm fiber laser using mAX phase Cr2TiAlC2 saturable absorber

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Optoelectronics Letters 2025年第1期21卷 7-12页

作者： ahmed Shakir AL-HITI Hiba HASSAN Department of Electrical Engineering Faculty of Engineering University of Anbar Department of Laser and Optoelectronics Engineering University of Technology-Iraq

We demonstrated a new type of mAX phase material, chromium titanium aluminum carbide（Cr2TiAlC2） polymer film, to generate a passively Q-switched erbium-doped fiber laser（EDFL）. The film thickness was measured to be around 45 μm, which was fabricated using the embedding method with polyvinyl alcohol（PVA） polymer as hoster. The saturable absorber（SA） film demonstrates a dual-wavelength passively Q-switched EDFL which operates at 1 531 nm and 1 560.19 nm, respectively. The Q-switching pulse duration could be varied from 2.46 μs to 770 ns, while the repetition rate varied from 92.76 kHz to 106.6 kHz with an increasing input pumping range from 154 mW to 300 mW. The maximum output power and pulse energy of 15.05 mW and 141.18 nJ were obtained at the maximum input power of 300 mW, respectively.

关键词： Saturable absorbers

Standard precaution measurements during ophthalmology practice in the pandemic stage of COVID-19

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International Journal of Ophthalmology(English edition) 2020年第7期13卷 1017-1022页

作者： ahmed mohamed Reda Wael m.ahmed Department of ophthalmology Faculty of MedicineAin Sham UniversityCairo 11566Egypt Dar Eloyoun Eye Laser Centers Muscat 118Oman

AIm:To take specific precautions and keep a safe practice during providing ophthalmology health services without compromising the patient’s safety as well as the team workers and the community in the pandemic stage of corona virus disease 2019(COVID-19).mETHODS:Applying patient circulation scheme implemented in our ophthalmology centers with the guidance of ministry of health infection control guidelines star ted from the moment that we receive a call or Whats App message or Facebook inquiry from patients until 21 d after patients first visit if *** directions were ***,community awareness of the disease and the ophthalmology related advices in how eye can transfers the infection and how to protect our eyes not to be infected through videos interviews of our consultants and distribution in social media like Instagram,Facebook,Whats App pages radio and TV interviews as well as leaflet health awareness for distribution for ***,scheduling of patients’appointments to prevent overcrowdings and cross ***,protective measurements tools in the center to detect and prevent any exposure of the patients to patients and to protect medical staff,COVID-19 scoring system was set up to identify patients with fever,respiratory symptoms,acute conjunctivitis or recent travel to outbreak areas and to encourage these individuals to postpone their appointments for at least 21 *** use of personal protective equipment was *** all the elective surgeries keeping only the emergency types advised by fourth:how to deal with our patients if they need an urgent ophthalmological intervention and how to deal with suspected cases of corona if any cases ***:Our measures helped our colleagues to try to keep providing ophthalmology health services without increasing the incidence of infection for COVID-19 until this pandemic is ***:In our practice,ophthalmologists should work with new aura of social media to facilitate the

关键词： corona virus COVID-19 Instagram Facebook WhatsApp personal protective equipment

Disturbance Evaluation in Power System Based on machine Learning

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Computers, materials & Continua 2022年第4期71卷 231-254页

作者： Emad m.ahmed mohamed A.ahmed Ziad m.Ali Imran Khan Department of Electrical Engineering College of EngineeringJouf UniversitySakaka72388Al-JoufSaudi Arabia Department of Electrical Engineering College of EngineeringPrince Sattam bin Abdulaziz UniversityWadi Addawaser11991Saudi Arabia Department of Electrical Engineering Aswan Faculty of EngineeringAswan UniversityAswan81542Egypt Department of Electrical Engineering University of Engineering and Technology PeshawarPakistan

The operation complexity of the distribution system increases as a large number of distributed generators(DG)and electric vehicles were introduced,resulting in higher demands for fast online reactive power *** a power system,the characteristic selection criteria for power quality disturbance classification are not *** classification effect and efficiency needs to be improved,as does the generalization *** order to categorize the quality in the power signal disturbance,this paper proposes a multi-layer severe learning computer auto-encoder to optimize the input weights and extract the characteristics of electric power quality ***,a multi-label classification algorithm based on rating is proposed to understand the relationship between the labels and identify the various power quality *** two algorithms are combined to construct a multi-label classification model based on a multi-level extreme learning machine,and the optimal network structure of the multi-level extreme learning machine as well as the optimal multi-label classification threshold are *** proposed method can be used to classify the single and compound power quality disturbances with improved classification effect,reliability,robustness,and anti-noise performance,according to the experimental *** hamming loss obtained by the proposed algorithm is about 0.17 whereas mL-RBF,SVm and mL-KNN schemes have 0.28,0.23 and 0.22 respectively at a noise intensity of 20 *** average precision obtained by the proposed algorithm 0.85 whereas the mL-RBF,SVm and mL-KNN schemes indicates 0.7,0.77 and 0.78 respectively.

关键词： Optimal power flow optimization algorithm deep learning power systems

Complementary parametric probit regression and nonparametric classi?cation tree modeling approaches to analyze factors affecting severity of work zone weather-related crashes

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Journal of modern Transportation 2019年第2期27卷 129-140页

作者： Ali Ghasemzadeh mohamed m.ahmed Department of Civil and Architectural Engineering University of Wyoming

Identifying risk factors for road traffic injuries can be considered one of the main priorities of transportation agencies. more than 12,000 fatal work zone crashes were reported between 2000 and 2013. Despite recent efforts to improve work zone safety, the frequency and severity of work zone crashes are still a big concern for transportation agencies. Although many studies have been conducted on different work zone safety-related issues, there is a lack of studies that investigate the effect of adverse weather conditions on work zone crash severity. This paper utilizes probit–classification tree, a relatively recent and promising combination of machine learning technique and conventional parametric model, to identify factors affecting work zone crash severity in adverse weather conditions using 8 years of work zone weatherrelated crashes (2006–2013) in Washington State. The key strength of this technique lies in its capability to alleviate the shortcomings of both parametric and nonparametric models. The results showed that both presence of traffic control device and lighting conditions are significant interacting variables in the developed complementary crash severity model for work zone weather-related crashes. Therefore, transportation agencies and contractors need to invest more in lighting equipment and better traffic control strategies at work zones, specifically during adverse weather conditions.

关键词： Adverse weather Work zone Safety Crash characteristics Probit model Decision tree

Rangeland water requirement satisfaction index under rainfall variability and predicting future rainfall scenarios: implication for availability of feed resources

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Ecological Processes 2017年第1期6卷 264-272页

作者： Hassen m.ahmed Zewdu K.Tessema Adugna Tolera Diriba Korecha School of Animal and Range Sciences College of Agriculture and Environmental SciencesPO Box 138Dire DawaEthiopia School of Animal and Range Sciences Hawassa UniversityPO Box 222HawassaEthiopia Famine Early Warning Systems Network PO Box 1090Addis AbabaEthiopia School of Animal and Range Sciences College of Agriculture and Environmental SciencesHaramaya UniversityPO Box 1632Dire DawaEthiopia

Introduction:Rangeland ecosystems provide multiple ecosystem services,including feed resources for wild and domestic herbivores in semi-arid ***,under the ever increasing environmental changes,the impact of rainfall variability on the productivity and vegetation dynamics of rangelands are the great challenges that pastoral community are facing *** a result,the potentials of most rangelands in semi-arid ecosystems affect the ***,we studied the interconnections between the long-term rainfall variation and the rangeland Water Requirement and Satisfaction Index(WRSI)in mieso,Jigjiga,and Shinile districts under pastoral conditions of ***:The base period rainfall data(1984–2015)was obtained from the National meteorological Agency of Ethiopia,whereas the future rainfall trend was predicted using markSim software(Representative Concentration Pathways 4.5 GHG concentration trajectory).mann-Kendall’s statistical tests,coefficient of variation,LEAP software(version 2.61),and minitab Software(version 15)were used to assess the relationship between rangeland WRSI and long-term rainfall ***:The result indicated that mean annual rainfall anomaly had strong positive correlation with rangeland WRSI in mieso(Pmount and distribution in all studied districts in pastoral areas of ***:The mean annual rainfall anomaly is correlated with the rangeland ***,the future rainfall trend analysis indicated that variability of rainfall would be expected in between the years 2020–2049,2040–2069,and 2070–***,the future rainfall variability would limit future rangeland WRSI under pastoral conditions of Ethiopia.

关键词： LEAP software Pastoralist Rangeland water requirement Trend analysis

Experimental and mathematical modeling of Cr(Ⅵ) removal using nano-magnetic Fe3O4-coated perlite from the liquid phase

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Chinese Journal of Chemical Engineering 2020年第6期28卷 1582-1590页

作者： Ismail m.ahmed mostafa m.Hamed Sayed S.metwally Chemistry Department College of ScienceJouf UniversitySkakaSaudi Arabia Hot Laboratories and Waste management Center Atomic Energy Authority13759 CairoEgypt

modification of perlite using nano-magnetic iron oxide was implemented to produce nano-magneticFe3O4-coated perlite composite(Fe3O4/Perlite).The prepared composite was characterized using Scanning Electron microscopy,Fourier-Transform Infrared spectroscopy and Powder X-ray *** potentiality of both perlite and Fe3O4/Perlite composite to eliminate Cr(VI)from the environmentally relevant water was *** influence of main factors which could affect the adsorption was studied including;pH of medium,shaking time and Cr(VI)ions *** experimental outcome demonstrated that the modification of perlite by nano-magnetic Fe3O4 showed a significantly enhanced Cr(VI)removal efficiency relative to that of unmodified *** the kinetic studies,the experimental data fitted well with the pseudo-second-order ***,it proposes that Langmuir isotherm is more adequate than the Freundlich isotherm for both perlite and modified *** results recommended that Fe3O4/Perlite composite had a great potential as an economic and efficient adsorbent of Cr(VI)from contaminated water,which has huge application potential.

关键词： Nano-magnetic Composite Kinetics Isotherm Perlite Adsorption

Surface activation of viscose textiles via air,argon,and oxygen dielectric barrier discharge plasma:influence of peak voltage

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Plasma Science and Technology 2024年第7期26卷 134-147页

作者： Shrouk ELASHRY Usama m.RASHED mostafa A.WAHBA Hend m.ahmed Nabil m.ELSIRAGY Plasma Laboratory Physics DepartmentFaculty of scienceTanta UniversityTanta 31527Egypt Physics Department Faculty of Science(Male)Al-Azhar UniversityCairo 11651Egypt Textile Research Industrial Division National Research CentreDokkiGiza 12622Egypt

This paper discusses the use of atmospheric pressure dielectric barrier discharge(DBD)plasma treatment to enhance the surface qualities of viscose *** study explores the effects of different plasma gases,discharge voltages,and exposure times on the treated *** findings emphasize the importance of optimizing the plasma's peak voltage to achieve the desired surface treatment *** document also presents data on colour strength,wettability,colour fastness,and tensile strength of the treated fabrics,as well as scanning electron microscopy(SEm)analysis of surface morphology and chemical analysis using fouriertransition infrared spectroscopy(FTIR)and energy dispersive X-ray(EDX).The results show that treatment at a peak voltage of 11.83 k V is more efficient,except for the tensile strength which is enhanced at a peak voltage of 8.92 k *** oxygen plasma treatment significantly improves the colour strength,which exhibits an increase from 11 to *** intensified colour was attributed to the significant influence of electrostatic interactions between the charged hydroxyl groups of the oxygen plasma treated viscose textiles and the dye molecules,which enhance the *** oxygen DBD plasma exhibits a higher ability to enhance the properties of textiles when compared to air and argon *** study presents a sustainable,economical,secure,and ecologically friendly approach to explore new fabrics for specific uses.

关键词： Lissajous diagrams printability wettability tensile strength SEm EDX FTIR