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Prediction of Vibration Characteristics in Beam Structure Using Sub-Scale Modeling with Experimental Validation

Chinese Journal of Mechanical Engineering 2015年第5期28卷 928-934页

作者： ZAI Behzad Ahmed sami saad KHAN M Amir AHMAD Furqan PARK Myung Kyun Structure Design and Development Directorate Institute of Space Technology Department of Civil and Environmental Engineering KAIST Department of Mechanical Engineering Myongji University

Geometric or sub-scale modeling techniques are used for the evaluation of large and complex dynamic structures to ensure accurate reproduction of load path and thus leading to true dynamic characteristics of such structures. The sub-scale modeling technique is very effective in the prediction of vibration characteristics of original large structure when the experimental testing is not feasible due to the absence of a large testing facility. Previous researches were more focused on free and harmonic vibration case with little or no consideration for readily encountered random vibration. A sub-scale modeling technique is proposed for estimating the vibration characteristics of any large scale structure such as Launch vehicles, Mega structures, etc., under various vibration load cases by utilizing precise scaled-down model of that dynamic structure. In order to establish an analytical correlation between the original structure and its scaled models, different scale models of isotropic cantilever beam are selected and analyzed under various vibration conditions（ i.e. free, harmonic and random） using finite element package ANSYS. The developed correlations are also validated through experimental testing The prediction made from the vibratory response of the scaled-down beam through the established sets of correlation are found similar to the response measured from the testing of original beam structure. The established correlations are equally applicable in the prediction of dynamic characteristics of any complex structure through its scaled-down models. This paper presents modified sub-scale modeling technique that enables accurate prediction of vibration characteristics of large and complex structure under not only sinusoidal but also for random vibrations.

关键词： sub-scale modeling resonance frequency vibration characteristics scale factors power spectral density

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Factors Influencing Employees on Compliance with Cybersecurity Policies and Their Implications for Protection of Information and Technology Assets in Saudi Arabia

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Intelligent Information Management 2023年第4期15卷 259-283页

作者： sami saad Alsemairi Department of Digital Transformation and Information Programs Institute of Public Administration Jeddah Saudi Arabia

In the current digital era, it is difficult to preserve the confidentiality, integrity, and availability of an organization’s information and technology assets against cyber attacks. Organizations cannot rely solely on technical solutions for defense, since many cyber attacks attempt to exploit non-technical vulnerabilities such as how well employees comply with the organization’s cybersecurity policies. This study surveyed 245 randomly selected employees of government organizations in the Kingdom of Saudi Arabia with an electronically distributed questionnaire about factors that influence employees’ compliance with cybersecurity policies. The study found that ethical factors had the most influence on employee compliance with cybersecurity policies, followed in decreasing order of influence by legislative factors, technical factors, and administrative factors.

关键词： Cybersecurity Policies Compliance Protection Information and Technology Assets

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Antioxidant and lipoxygenase inhibitory properties of a novel flavonoid from Pistacia chinensis Bunge and its molecular docking analysis

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Traditional Medicine Research 2025年第2期10卷 30-36页

作者： Abdur Rauf Zuneera Akram Naveed Muhammad Najla AlMasoud Taghrid saad Alomar Saima Naz Abdul Wadood Chandni Hayat Marcello Iriti Department of Chemistry University of SwabiAmbar 23561Pakistan Department of Pharmacology Faculty of Pharmaceutical SciencesBaqai Medical UniversityKarachi 74600Pakistan Department of Pharmacy Abdul Wali Khan University MardanMardan 23200Pakistan Department of Chemistry College of SciencePrincess Nourah bint Abdulrahman UniversityRiyadh 11671Saudi Arabia Department of Biotechnology BKUC-Bacha Khan University CharsaddaCharsadda 24620Pakistan Department of Biochemistry Abdul Wali Khan University MardanMardan 23200Pakistan Department of Biomedical Surgical and Dental SciencesUniversity of MilanMilan 20129Italy National Interuniversity Consortium of Materials Science and Technology(INSTM) Firenze 50121Italy

Background:Pistacia chinensis Bunge has been traditionally used to manage various conditions,including asthma,pain,inflammation,hepatoprotection,and *** study was conducted to investigate the antioxidant and anti-lipoxygenase(LOX)properties of the isolated compound 2-(3,4-dihydroxyphenyl)-5,7-dihydroxy-4H-chromen-4-one from Pistacia ***:LOX assay and antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl(DPPH)assay were *** docking studies were conducted using a molecular operating ***:The LOX assay revealed significant inhibitory effects at 0.2µM concentration,with an IC50 value of 37.80µ*** antioxidant effect demonstrated dose-dependency across 5 to 100µg/mL concentrations,reaching 93.09%at 100µg/mL,comparable to ascorbic acid’s 95.43%*** docking studies highlighted strong interactions with the lipoxygenase enzyme,presenting an excellent docking score of-10.98 kcal/***:These findings provide valuable insights into Pistacia chinensis’chemical components and biological effects,reinforcing its traditional medicinal applications.

关键词： Pistacia chinensis Bunge antioxidant DPPH assay antilipoxygenase docking analysis

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Complement-dependent neuroinflammation in spinal cord injury:from pathology to therapeutic implications

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Neural Regeneration Research 2025年第5期20卷 1324-1335页

作者： Hassan saad Bachar El Baba Ali Tfaily Firas Kobeissy Juanmarco Gutierrez Gonzalez Daniel Refai Gerald R.Rodts Christian Mustroph David Gimbel Jonathan Grossberg Daniel L.Barrow Matthew F.Gary Ali M.Alawieh Department of Neurosurgery Emory University School of MedicineAtlantaGAUSA Department of Neurology Yale UniversityNew HavenCTUSA Center for Neurotrauma Multiomics&Biomarkers(CNMB)Morehouse School of MedicineAtlantaGAUSA

Spinal cord injury remains a major cause of disability in young adults,and beyond acute decompression and rehabilitation,there are no pharmacological treatments to limit the progression of injury and optimize recovery in this *** the thorough investigation of the complement system in triggering and propagating cerebral neuroinflammation,a similar role for complement in spinal neuroinflammation is a focus of ongoing *** this work,we survey the current literature investigating the role of complement in spinal cord injury including the sources of complement proteins,triggers of complement activation,and role of effector functions in the *** study relevant data demonstrating the different triggers of complement activation after spinal cord injury including direct binding to cellular debris,and or activation via antibody binding to damage-associated molecular *** effector functions of complement have been implicated in spinal cord injury,and we critically evaluate recent studies on the dual role of complement anaphylatoxins in spinal cord injury while emphasizing the lack of pathophysiological understanding of the role of opsonins in spinal cord *** this pathophysiological review,we systematically review the different translational approaches used in preclinical models of spinal cord injury and discuss the challenges for future translation into human *** review emphasizes the need for future studies to dissect the roles of different complement pathways in the pathology of spinal cord injury,to evaluate the phases of involvement of opsonins and anaphylatoxins,and to study the role of complement in white matter degeneration and regeneration using translational strategies to supplement genetic models.

关键词： complement neuroinflammation neuroplasticity regeneration spinal cord injury targeted therapy

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Thermal explosion of a reactive gas mixture at constant pressure for non-uniform and uniform temperature systems

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Defence Technology（防务技术） 2022年第10期18卷 1842-1851页

作者： saad A.El-Sayed Mechanical Power Engineering Dept.Zagazig University ZagazigAlshrkiaEgypt

In this study,the approximate and exact solutions for the stationary-state of the solids model with neglecting reactant consumption for both non-uniform and uniform temperature systems were applied on gas ignition under a constant pressure *** criticality conditions for a slab,an infinite cylinder,and a sphere are determined and discussed using dimensionless temperatures under constant ambient and surface temperatures for a non-uniform temperature *** solution for a Semenov model with convection heat loss was also *** solution of the Semenov problem for constant volume or density as a solid and constant pressure were *** critical parameterδis calculated and compared with those of Frank-Kamenetskii solution *** validation of the calculated ignition temperatures with other exact solution and experimental results were *** relation between critical parameters form Semenov and *** solution was introduced.

关键词： Thermal explosion Approximate solution Critical conditions Distributed and uniform temperature systems

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Decoherence Effect and Beam Splitters for Production of Quasi-Amplified Entangled Quantum Optical Light

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Communications in Theoretical Physics 2018年第3期69卷 311-316页

作者： saad Rfifi Laboratoire des Sciences et Technologies Avances Facult Polydisciplinaire de LaracheUniversit Abdelmalek ESSAADI

We let a set of beam splitters of vacuum mode with a chosen transmittance parameter η in interaction with a separable coherent *** model induces the production of an attenuated quantum channels based on entangled optical ***,the decoherence effect is exploited positively here to generate such kind of quantum ***,the amplitude damping and the entanglement amount of these produced channels are enhanced thereafter by a probabilistic quasi amplification process using again a 50 : 50 beam splitter.

关键词： beam splitters production quasi probabilistic amplification quantum channels decoherence effect entangled optical states entanglement amount

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Effects of location, orchard type, laying period and nest position on the reproductive performance of Turtle Doves(Streptopelia turtur) on intensively cultivated farmland

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Chinese Birds 2016年第1期7卷 68-78页

作者： saad Hanane Forest Research Center High Commission for Water Forests and Desertification Control Avenue Omar Ibn El Khattab

Background: Until recently little was known about factors affecting reproductive parameters of the Turtle Dove(Streptopelia turtur) on intensively cultivated farmland in the Mediterranean area. In this study, the reproductive parameters of this game species were evaluated in relation to location, orchard type, laying period and nest position in central ***: A total of 317 nests were found and analyzed across five breeding seasons(2004–2008) in the Haouz and Tadla regions, over two major agro-ecosystems made up of olive and orange orchards. Nest position, laying period, clutch size and the number of chicks hatched and fledged per nest were determined on 120 study plots. I used Generalized Linear Models(GLMs) with a Poisson distribution and a log link function, including the logarithm of the number of eggs in each clutch as an offset to model the number of chicks hatched and fledged per ***: Clutch-size was not affected by location, orchard type, laying period or nest position. The number of chicks hatched per nest differed between orchard types; they were greater in olive orchards(1.33 ± 0.06) than in orange ones(1.03 ± 0.08), whereas the number of chicks fledged per nest consistently differed with laying period and orchard type, which were higher in the early laying period(1.22 ± 0.07) than in the late period(0.93 ± 0.08) and higher in olive orchards(1.22 ± 0.06) than in orange orchards(0.90 ± 0.06). Neither location nor nest position were related to variation in the fledging success of the Turtle ***: Olive orchards and the early laying period confer better nesting conditions than orange orchards and the late laying period. Although nest position could be different in each orchard type, it did not affect the breeding success of the Turtle Dove, suggesting that factors other than tree characteristics are influential. Further studies are needed to improve our understanding of the effects of anthropogenic disturbance, especially agric

关键词： Agroecosystems Breeding parameters Columbid species Gamebird species Morocco

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The emancipation of testosterone from niche iormone to multi-system player

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Asian Journal of Andrology 2015年第1期17卷 58-60页

作者： Farid saad Bayer Pharma Global Medical Affairs Andrology Berlin Germany Gulf Medical University School of Medicine Ajman United Arab Emirates.

It is no exaggeration to say that our lconceptualization of the （patho-） physiological functions of testosterone has undergone a revolutionary development over the last three decades. The traditional thinking was that the biological functions of testosterone were restricted mainly to the area of reproduction and male sexuality. However, scientific research has clearly demonstrated that testosterone is a multi-system hormone serving a wide range of hitherto unsuspected biological functions.

关键词： The emancipation testosterone from niche

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Testosterone induced apoptosis in colon cancer cells is regulated by PI3K/Racl signaling

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Asian Journal of Andrology 2013年第6期15卷 831-834,I0011页

作者： saad Alkahtani Department of Zoology Science College King Saud University Riyadh 11352 Saudi Arabia

Recently, it has been reported that testosterone membrane signaling regulates actin reorganization and induces pro-apoptotic responses in colon tumor cells. In the present study the membrane androgen receptors （mARs）-induced activation of Rac I GTPase and the involvement of PI3K/Racl signaling in controlling the apoptotic responses in testosterone treated Caco2 colon cancer cells has been analyzed. In line with previous findings, activation of mAR by testosterone conjugates triggered early and transient actin reorganization as indicated by the significant decrease of the G/Total actin ratio after 15- and 30-min treatment of the cells. Interestingly, stimulation of mAR rapidly activated the Racl GTPase. This effect was evident after 15 min and persisted for at least 24 h. Testosterone induced Rac I activation was fully blocked in Caco2 cells pre-treated with the PI3K inhibitor wortmannin, indicating that Racl signaling is acting downstream of the PI3K pathway. Remarkably, when cells were pre-treated with wortmannin that blocks the PI3K/Racl signaling, apoptotic response was almost fully inhibited. These finding suggest that Racl activation, triggering actin redistribution, is involved in testosterone induced pro-apoptotic responses governed by mAR activation and emphasize the regulatory role of PI3K/Racl signaling in colon tumors.

关键词： actin apoptosis colon cancer cell testosterone

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Melanoma Identification Through X-ray Modality Using Inception-v3 Based Convolutional Neural Network

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Computers, Materials & Continua 2022年第7期72卷 37-55页

作者： saad Awadh Alanazi College of Computer and Information Sciences Jouf UniversitySakakaAljouf72341Saudi Arabia

Melanoma,also called malignant melanoma,is a form of skin cancer triggered by an abnormal proliferation of the pigment-producing cells,which give the skin its *** is one of the skin diseases,which is exceptionally and globally dangerous,Skin lesions are considered to be a serious ***-based early recognition and detection procedure is fundamental for melanoma *** detection of melanoma using dermoscopy images improves survival rates *** the same time,well-experienced dermatologists dominate the precision of ***,precise melanoma recognition is incredibly hard due to several factors:low contrast between lesions and surrounding skin,visual similarity between melanoma and non-melanoma lesions,and so ***,reliable automatic detection of skin tumors is critical for pathologists’effectiveness and *** take care of this issue,numerous research centers around the world are creating autonomous image processing-oriented *** suggested deep learning methods in this article to address significant tasks that have emerged in the field of skin lesion image processing:we provided a Convolutional Neural Network(CNN)based framework using an Inception-v3(INCP-v3)melanoma detection scheme and accomplished very high precision(98.96%)against melanoma *** classification framework of CNN is created utilizing TensorFlow and Keras in the backend(in Python).It likewise utilizes Transfer-Learning(TL)*** is prepared on the data gathered from the“International Skin Imaging Collaboration(ISIC)”*** experiments show that the suggested technique outperforms state-of-the-art methods in terms of predictive performance.

关键词： Deep learning chronic obstructive pulmonary disease chronic bronchitis convolutional neural network X-ray images

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