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Nanosecond pulse， dual-wavelength Q-switched 1.5 μm fiber laser using mAX phase CrTialCsaturable absorber

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Optoelectronics Letters 2024年

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. The film thickness was measured around 45 μm which was fabricated using the embedding method with PVA polymer as hoster. The SA film demonstrates a dual-wavelength passively Q-switched erbium-doped fiber laser （edFL） which operates at 1531 nm and 1560.19 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 of 154 mW to 300 mW. The maximum output power and pulse energy of 15.05 mW and 141.18 nJ were obtained at a maximum input power of 300 mW， respectively. To the best of our knowledge， this is the first time that on dual-wavelength Q-switched edF laser by Cr2TialC2as SA.

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Recent progress in two-dimensional metallenes and their potential application as electrocatalyst

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Journal of Energy Chemistry 2024年第7期94卷 577-598页

作者： Umer Shahzad mohsin Saeed muhammad Fazle rabbee Hadi m.marwani Jehan Y.al-Humaidi muhammad altaf raed H.althomali Kwang-Hyun Baek md.rabiul Awual mohammed m.rahman Department of Chemistry Faculty of ScienceKing Abdulaziz UniversityJeddah 21589Saudi Arabia Department of Biotechnology Yeungnam UniversityGyeongsanSouth Korea Center of Excellence for Advanced materials Research(CEAmR) King Abdulaziz UniversityJeddah 21589Saudi Arabia Department of Chemistry College of SciencePrincess Nourah Bint Abdulrahman UniversityP.O.BOX 84428Riyadh 11671Saudi Arabia Department of Chemistry Center of Excellence for Innovation in Chemistry(PERCH-CIC)Center of Excellence in Materials Science and TechnologyFaculty of ScienceChiang Mai UniversityChiang Mai 50200Thailand Department of Chemistry College of Art and SciencePrince Sattam Bin Abdulaziz UniversityWadi Al-Dawasir 11991Saudi Arabia Western Australian School of mines:minerals Energy and Chemical EngineeringCurtin UniversityGPO Box U 1987PerthWA 6845Australia

In this article,we looked at metallenes,a novel class of two-dimensional(2D)metals that are attracting interest in the energy and catalysis *** is one area where their exceptional physicochemical and electrical characteristics might be *** are unique because they include several metal atoms that are not in a coordinated *** makes them more active and improves their atomic uti-lization,which in turn increases their catalytic *** article delves into the potential of two-dimensional metals as electrocatalysts for carbon dioxide reduction,fuel oxidation,oxygen evolution,and oxygen reduction reactions in the context of sustainable energy *** to the exception-ally high surface-to-volume ratio,large surface area as well as their optimized atomic use efficiency,2D materials defined by atomic layers are crucial for surface-related sustainable energy *** to its exceptional properties,such as high conductivity and the ability to enhance the exposure of active metal sites,2D metallenes have recently attracted a lot of interest for use in catalysis,electronics,and energy-related *** their highly mobility,adjustable surface states,and electrical struc-tures that can be fine-tuned,2D metallenes are promising nanostructure materials for use in energy con-version with the sustainable applications.

关键词： metallenes Electrocatalysts Electrochemical processes Atomically thin structure

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Deterministic and Stochastic Fractional Order model for Lesser Date moth

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Computer Systems Science & Engineering 2022年第2期40卷 749-764页

作者： moustafa El-shahed Asmaa m.al-Dububan Department of mathematics Unaizah College of Sciences and ArtsQassim UniversityP.O.Box 3771Unaizah51911Saudi Arabia Department of mathematics Buraydah College of Sciences and ArtsQassim UniversityP.O.Box 1162Buraydah51431Saudi Arabia

In this paper,a deterministic and stochastic fractional order model for lesser date moth(LDm)using mating disruption and natural enemies is proposed and *** interaction between LDm larvae,fertilized LDm female,unfertilized LDm female,LDm male and the natural enemy is *** order to clarify the characteristics of the proposed deterministic fractional order model,the analysis of existence,uniqueness,non-negativity and boundedness of the solutions of the proposed fractional-order model are *** addition,some sufficient conditions are obtained to ensure the local and global stability of equilibrium *** occurrence of local bifurcation near the equilibrium points is investigated with the help of Sotomayor’s *** simulations are conducted to illustrate the properties of the proposed fractional order model with respect to the intrinsic growth rate of the LDm larvae,natural enemy’s mortality rate,predation rate,sex pheromone trap parameter,fractional order and environmental *** impact of mating disruption on lesser date moth is ***,a numerical approximation method is developed for the proposed stochastic fractional-order model.

关键词： Lesser date moth stochastic stability natural enemies Sotomayor’s theorem mating disruption

A Pioneering Approach to the Synthesis of Silver Nanoparticles

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Journal of materials Science and Chemical Engineering 2024年第7期12卷 14-22页

作者： Wasan A. al-Dulaimi Zeena m. al-Azzawi Emad K. al-Shakarchi Physics Department College of Science Al-Nahrain University Baghdad Iraq

Our research introduces a groundbreaking chemical reduction method for synthesizing silver nanoparticles, marking a significant advancement in the field. The nanoparticles were meticulously characterized using various techniques, including optical analysis, structural analysis, transmission electron microscopy (TEm), and field-emission scanning electron microscope (FESEm). This thorough process instills confidence in the accuracy of our findings. The results unveiled that the silver nanoparticles had a diameter of less than 20 nm, a finding of great importance. The absorption spectrum decreased in the peak wavelength range (405 - 394 mm) with increasing concentrations of Ag nanoparticles in the range (1 - 5%). The XRD results indicated a cubic crystal structure for silver nanoparticles with the lattice constant (a = 4.0855 Å), and miller indices were (111), (002), (002), and (113). The simulation on the XRD pattern showed a face center cubic phase with space group Fm-3m, providing valuable insights into the structure of the nanoparticles.

关键词： Chemical Reduction method UV-VIS Absorption Spectrometer Field-Emission Scanning Electron microscope (FESEm) Transmission Electron microscopy (TEm)

Advancements in Fixed Point Theorems for α-Geraghty Contractions in Complete metric Space

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Journal of mathematical Research with Applications 2024年第5期 697-710页

作者： V.C.BORKAR mohammed m.A.TalEB Saeed A.A.al-SalEHI School of mathematical at Yeshwant mahavidyalaya Swami Ramanand Teerth Marathwada University School of mathematical at Science College Swami Ramanand Teerth Marathwada University Department of mathematics Hodeidah University Department of mathematics Aden University

This article improves and advances the results achieved by Vishal and Naveen, leveraging the use of Lebesgue integrable functions. Going beyond, we investigate fixed point theorems associated with a concept introduced by Ovidiu Popescu. Our research not only bolsters the theoretical framework but also unveils practical applications in the domain of Lebesgue integrals as in Example 3.6. Furthermore, our contribution enhances the understanding of fixed point theorems in metric spaces and introduces novel perspectives in the study of generalized α-Geraghty contractive mappings on Lebesgue integrals.

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Coronary Artery Patterns in Diabetic Patients Undergoing Diagnostic Coronary Angiography-Data from a major Cardiac Center in Yemen

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World Journal of Cardiovascular Diseases 2024年第4期14卷 268-281页

作者： mohammed m. al-Kebsi Yehia al-Ezzy Amatasamad al-Tanobi Ayman A. mohammed Department of Cardiology Faculty of Medicine and Health Sciences Sana&#8217a University Sana&#8217a Yemen Cardiac Center Al-Thawra Modern General Hospital Sana&#8217a Yemen

Background: Diabetes mellitus (Dm) is independently associated with an increased risk of cardiovascular mortality and morbidity, including coronary artery disease (CAD). CAD is a shared burden disease and the leading cause of death in developed and developing countries. We aimed to assess the angiographic patterns of coronary arteries in patients with Dm in a developing country (Yemen) as the first study. methods: This study is a cross-sectional, prospective, observational study that includes a total of 250 patients who were admitted for elective diagnostic coronary angiography. Results: 96 (38.4%) patients were diabetics;68% were male;mean age was 57 ± 11 years. The incidence of three-vessel disease was 31.2% of patients. Considering the severity of lumen occlusion, (11.2%) of patients had non-significant lesions, (37.6%) of patients had significant lesions, and (32%) had total occlusive lesions. Lesions were of LAD in 76%, RCA in 60%, and LCX in 52% of the population. Among diabetics, two and 3-vessel diseases (33.3% vs. 20.8% & 50% vs. 19.5%, P = 0.001), left main lesion (10.4% vs. 2.6%, P = 0.012), significant stenosis (41.7% vs. 35.1%, P = 0.032), total occlusion of coronary arteries (43.8% vs. 19.5%, P = 0.032) and type C lesion (66.7% vs. 35.1%, P = 0.010) were more frequent than non-Dm patients. Conclusion: The burden of significant and severe coronary lesions is more common among Dm, which may be the major cause of morbidity and mortality of Dm in developing countries.

关键词： Diabetes mellitus Coronary Artery Diseases Coronary Angiography

Double sampling derivatives and truncation error estimates

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Applied mathematics(A Journal of Chinese Universities) 2018年第2期33卷 209-224页

作者： rashad m.Asharabi Aisha m.al-Hayzea Department of mathematics College of Arts and Sciences Najran University

This paper investigates double sampling series derivatives for bivariate functions defined on R2 that are in the Bernstein space. For this sampling series, we estimate some of the pointwise and uniform bounds when the function satisfies some decay conditions. The truncated series of this formula allow us to approximate any order of partial derivatives for function from Bernstein space using only a finite number of samples from the function itself. This sampling formula will be useful in the approximation theory and its applications, especially after having the truncation error well-established. Examples with tables and figures are given at the end of the paper to illustrate the advantages of this formula.

关键词： double sampling series truncation error bounds convergence rate

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Effects of C_8 ventral root avulsion or transection on spinal alpha motoneurons in adult rats A qualitative light and electron microscopic study

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Neural Regeneration Research 2008年第2期3卷 148-156页

作者： Khulood m.al-Khater Bassem Y.Sheikh Department of Anatomy College of MedicineKing Faisal UniversityDammam Department of Neurosurgery College of MedicineTaibah UniversityMadinahSaudi Arabia

BACKGROUND： Nerve root avulsion is a frequent finding in patients with brachial plexus injury following road traffic accidents or as a result of severe arm traction during complicated deliveries. This injury constitutes a challenging clinical and surgical problem. The morphological characteristics of motoneurons after nerve root avulsion deserve further analysis. OBJECTIVE： To study the different morphological changes of α-motoneurons under light and electron microscopy after C8 spinal ventral rootlets avulsion and transection at various stages. DESIGN： Controlled animal study. SETTING： Department of Anatomy, King Faisal University. mATERIalS： The experiment was carried out at the Department of Anatomy, College of medicine, King Faisal University between January 2005 and march 2006. Six adult Sprague Dawley rats weighing 200-350 g, irrespective of gender, were used for this study. The animals were bred at the animal house, College of medicine, King Faisal University, and fed on rat maintenance diet. Water and standard diet were supplied ad libitum. Animal interventions were carried out according to animal ethical standards. mETHODS： Three animals were randomly chosen for avulsion of the right ventral rootlets of C8 spinal nerves. The other three received transection of the right ventral rootlets of C8 spinal nerves. ①Avulsion experiment： After rats were anesthetized, the right ventral rootlets of C8 spinal nerves were identified. The ventral rootlets were avulsed from the spinal cord by traction with a fine hook （Fine Science Tools Inc., No. 10031-13, Germany）. Traction was exerted in a direction parallel to the course of the spinal root. Under the operating microscope, the C8 segment was exactly located. After checking the successfulness of the surgical procedure, the C8 segment was separated from the spinal cord. The outcome of the avulsion procedure was as follows： two animals had true avulsion, i.e., no remaining stump was attached to the spinal cord sur

关键词： nerve root avulsion transection

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Experimental and numerical study of effecting core configurations on the static and dynamic behavior of honeycomb plate with aluminum material

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DEFENCE TECHNOLOGY 2024年第9期39卷 177-192页

作者： Hamza, Nehad Abid allah al-Fatlwe, Fatima mohammed K. Talib, muna ali al Qasim Green Univ Engn Coll Babylon 51013 Iraq al Furat al Awsat Tech Univ ATU Engn Tech Coll Al Najaf Najaf 54003 Iraq

The sandwich panel incorporated a honeycomb core, a widely utilized composite structure recognized as a fundamental classification of composite materials. Comprised a core resembling a honeycomb, possessing thickness and softness, and is flank by rigid face sheets that sandwich various shapes and materials. This paper presents an examination of the static and dynamic analysis of lightweight plates made of aluminum honeycomb sandwich composites. Honeycomb sandwich plate samples are 300 mm long, and 300 mm wide, the heights of the core have been varied at four values ranging from 10 to 25 mm. The honeycomb core is manufactured from.aluminum material by using a novel technique namely resistance spot welding (RSW) instead of using adhesive material, which is often used when an industrial flaw is detected. Numerical optimization based on response surface methodology (RSm) and design of experiment software (DOE) was used to verify the current work. A theoretical examination of the crashworthiness behavior (maximum bending load, maximum deflection) and vibration attributes (natural frequency, damping ratio, transient temporal response) of honeycomb sandwich panels with different design parameters was also carried out. In addition, the finite element method-based ANSYS software was used to confirm the theoretical conclusions. The findings of the present work showed that the relationship between the natural frequency, core height, and cell size is direct. In contrast, the relationship between the natural frequency and the thickness of the cell wall is inverse. Conversely, the damping ratio is inversely proportional to the core height and cell size but directly proportional to the thickness of the cell wall. The study indicates that altering the core height within 10-25 mm leads to a significant increase of 82 % in the natural frequency and a notable decrease of 49% in the damping ratio. These findings are based on a specific cell size value of 0.01 m and a cell wall thicknes

关键词： Honeycomb Load Transient response Free vibration Natural frequency SANDWICH PANELS