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Computers, materials & Continua 2024年第9期80卷 3485-3506页

作者： Tajim md.Niamat Ullah Akhund waleed m.al-nuwaiser Department of Computer Science and Engineering(CSE) Daffodil International UniversityDhaka1216Bangladesh Graduate School of Science and Engineering Saga UniversitySaga8408502Japan Computer Science Department College of Computer and Information SciencesImam Mohammad Ibn Saud Islamic University(IMSIU)Riyadh11623Saudi Arabia

This study explores the impact of hyperparameter optimization on machine learning models for predicting cardiovascular disease using data from an IoST(Internet of Sensing Things)*** distinct machine learning approaches were implemented and systematically evaluated before and after hyperparameter *** improvements were observed across various models,with SVm and Neural Networks consistently showing enhanced performance metrics such as F1-Score,recall,and *** study underscores the critical role of tailored hyperparameter tuning in optimizing these models,revealing diverse outcomes among *** Trees and Random Forests exhibited stable performance throughout the *** enhancing accuracy,hyperparameter optimization also led to increased execution *** representations and comprehensive results support the findings,confirming the hypothesis that optimizing parameters can effectively enhance predictive capabilities in cardiovascular *** research contributes to advancing the understanding and application of machine learning in healthcare,particularly in improving predictive accuracy for cardiovascular disease management and intervention strategies.

关键词： Internet of sensing things(IoST) machine learning hyperparameter optimization cardiovascular disease prediction execution time analysis performance analysis wilcoxon signed-rank test

Status and prospects for symmetric organic redox flow batteries

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Journal of Energy Chemistry 2025年第1期100卷 125-143页

作者： md al Raihan C.Adam Dyker Department of Chemistry University of New Brunswick

As environmental concerns from fossil fuel consumption intensify, large-scale energy storage becomes imperative for the integration of renewable sources like wind, hydro, and solar with the electrical *** flow batteries, particularly those employing organic molecules, are positioned as a key technology for this purpose. This review explores the growing field of symmetric organic redox flow batteries(ORFBs) within this context. Unlike traditional asymmetric designs based on unique active materials for each electrode, symmetric ORFBs involve a single bipolar species for both electrodes. This review highlights the benefits of a symmetric design, and categorizes five distinct classes of organic bipolar molecules used in both aqueous and non-aqueous solvents. By providing a comprehensive overview of their cell cycling and performance characteristics, the strengths and weaknesses of the diverse categories of bipolar molecules are highlighted for both solvent systems, as are opportunities for future development. This should guide new research directions and advance the development of practical symmetric ORFBs.

关键词： Redox flow battery Symmetric battery Organic battery Aqueous electrolyte Non-aqueous electrolyte

Role of Air Staging in a Batch-Type Fixed Bed Biomass Combustor under Constant Primary Air

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Journal of Thermal Science 2024年第1期33卷 284-299页

作者： Awais JUNEJO Yasir m.al-ABDELI Jacobo PORTEIRO School of Engineering Edith Cowan UniversityJoondalupWA 6027Australia CINTECX Universidade de Vigo Grupo de Tecnoloxia Enerxetica(GTE)36310 VigoEspana

Staged combustion of biomass is the most suitable thermo-chemical conversion for achieving lower gaseous emissions and higher fuel conversion *** a staged fixed bed combustion of biomass,combustion air is supplied in two *** the first stage,primary air is provided below the fuel,whereas in the later stage,secondary air is supplied in the freeboard *** available literature on the effects of air staging(secondary air location) at a constant primary air flow rate on combustion characteristics in a batch-type fixed bed combustor is limited and hence warrants further *** study resolves the effect of air staging,by varying the location of secondary air in the freeboard at five secondary to total air ratios in a batch-type fixed bed *** are reported for the effects of these controlled parameters on fuel conversion rate,overall gaseous emissions(CO_(2),CO and NO_x) and temperature *** fuel used throughout was densified hardwood *** show that a primary freeboard length(distance between fuel bed top and secondary air injection) of200 mm has higher fuel conversion rates and temperatures as well as lower CO emissions,at a secondary to total air ratio of 0.75 as compared to primary freeboard length of 300 ***,NO_x emissions were found to be lower for a primary freeboard length of 300 mm as compared to 200 *** increase in secondary to total air ratio from 0.33 to 0.75 resulted in higher freeboard temperatures and lower CO as well as NO_x *** outcomes of this study will be helpful in the effective design of commercial scale biomass combustors for more efficient and environmentally friendly combustion.

关键词： fixed bed combustor biomass combustion air staging freeboard temperature burning rate gaseous emissions

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Temperature Uniformity,Correlations and the Flow Field in Swirling Impinging Jets

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Journal of Thermal Science 2023年第2期32卷 662-679页

作者： Zahir U.AHmED Yasir m.al-ABDELI Department of mechanical Engineering Khulna University of Engineering&TechnologyKhulna 9203Bangladesh School of Engineering Edith Cowan UniversityJoondalupWA 6027Australia

Infrared thermography,velocity and impingement pressure measurements alongside numerical modelling are used in this study to resolve(heated)surface temperature distributions of turbulent swirling impinging jets for two Reynolds numbers(Re=11600 and 24600).Whilst building upon earlier discoveries for this same geometry,this paper provides three new contributions:(1)identifying the role of impingement distance(H/D)as a deciding factor in the trade-off between more efficient heat transfer(at high swirl numbers)and achieving better substrate temperature uniformity(lower gradients),(2)developing correlations to predict Nusselt number for swirling and non-swirling cooling jets,and(3)predicting the underlying mixing field in these jets and its interplay with the thermal distributions *** indicate substrate temperature uniformity varies based on H/D and swirl intensity(S)with a significant level of thermal non-uniformity occurring in near-field impingement(H/D=1)at stronger swirl(S=0.59 and 0.74).Four correlations describing the effects of S,Re,and H on the average heat transfer and stagnation heat transfer are developed and yield accuracies of 8%and 12%,*** recirculation near the impingement surface is predicted at H/D=1 for stronger swirl jets which disappears at other substrate *** peak wall shear stress reduces and the flow impingement becomes radially wider at higher H/D and *** turbulence or eddy viscosity regions for non-swirling jets(S=0)are predicted in the shear layer and entrainment regions at H/D=1,but such turbulence is confined to the impingement and wall jet regions for strongly swirling flows.

关键词： Temperature uniformity Nusselt number IR imaging CTA RANS

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Factors affecting single-step transepithelial photorefractive keratectomy outcome in the treatment of mild,moderate,and high myopia:a cohort study

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International Journal of Ophthalmology(English edition) 2022年第5期15卷 786-792页

作者： mansour m.al-mohaimeed Department of Ophthalmology College of MedicineQassim UniversityQassimBuraidah 51452Saudi Arabia

AIm:To investigate the effect of preoperative factors on visual acuity,higher-order aberrations(HOAs),and index of success for spherical change(***)after transepithelial photorefractive keratectomy(t-PRK)for treating different grades of ***:This was a retrospective one-armed cohort study where patients with high,moderate,or mild myopia treated with single-step t-PRK using Amaris 500 Hz excimer laser were evaluated for visual acuity,refractive status,corneal topography,HOAs,***,and mean efficiency and safety index before and 6 mo after ***:A total of 154 eyes of 77 patients with mild(n=59),moderate(n=83),and high(n=12)myopia were *** efficiency and safety indices for vision recovery by single-step t-PRK were 98%and 100%,*** achieved spherical equivalent(SE)was within 1 diopter(D)in 151(98%)*** median of the *** was 1.18[interquartile range(IQR)1.0,1.4].The change in *** was significantly correlated with age(P=0.007),6.5 mm ablation zone(mann-Whitney U test,Pmild and moderate grade of myopia(Kruskal–Wallis test,Pal aberration,and aberration coefficient types of HOA increased significantly(Wilcoxon test,Pmo *** was a significant correlation between spherical aberration and aberration coefficient HOAs by myopia grades(Pmising short-term outcomes for refractive corrections and vision improvement to treat all three grades of myopia.

关键词： myopia refractive surgery trans-epithelial photorefractive keratectomy higher-order aberrations

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

Giardia duodenalis infection among rural communities in Yemen:A community-based assessment of the prevalence and associated risk factors

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Asian Pacific Journal of Tropical medicine 2017年第10期10卷 987-995页

作者： Hesham m.al-mekhlafi Endemic and Tropical Diseases Unit Medical Research CenterJazan UniversityJazanSaudi Arabia Department of Parasitology Faculty of MedicineUniversity of Malaya50603 Kuala LumpurMalaysia Department of Parasitology Faculty of Medicine and Health SciencesSana'a UniversitySana'aYemen

Objective: To investigate the prevalence and risk factors of Giardia infection among rural communities among rural communities in ***: In this cross-sectional study, a total of 605 stool samples were collected and screened for the presence of Giardia duodenalis(***) cysts and/or trophozoites by using three different diagnostic methods: direct smear, formalin-ether sedimentation,and trichrome staining.A pre-tested questionnaire was used to collect information on the demographic, socioeconomic, behavioural and environmental characteristics of the ***: Overall, 28.1%(170/605) of the participants were infected by *** prevalence was significantly higher among male participants compared to female(P = 0.034); however, it was not significant among different age groups(P > 0.05).Univariate and multivariate analyses identified four variables as the significant key risk factors of Giardia infection among the sampled *** are, in addition to being of the male gender, using unsafe water sources for drinking water, not washing hands after defecation, presence of other family members infected with Giardia, and close contact with domestic ***: The study reveals that Giardia infection is still prevalent among rural communities in *** provision of clean and safe drinking water, proper sanitation,and health education regarding personal hygiene practices, particularly handwashing, as well as identifying and treating infected family members is imperative and these interventions should be considered in a strategy to control intestinal parasites among these communities in order to curtail the transmission and morbidity caused by ***.

关键词： Giardia duodenalis Prevalence Risk factors Yemen

Combined corneal CXL and photorefractive keratectomy for treatment of keratoconus: a review

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International Journal of Ophthalmology(English edition) 2019年第12期12卷 1929-1938页

作者： mansour m.al-mohaimeed Department of Ophthalmology College of Medicine Qassim University

Keratoconus and iatrogenic keratectasia are the corneal ectatic disorders occurring due to biomechanical weakening of the cornea resulting in distorted images,myopia, and irregular astigmatism. Corneal collagen cross-linking(CXL) is performed to arrest keratoconus successfully. The main aim of this review is to discuss the safety and efficacy of the adjuvant therapies, such as the combination of CXL and photorefractive keratectomy(PRK) for the treatment of corneal ectatic disorders. A comprehensive literature search was performed using Pubm ed, mEDLINE, and Scopus using keywords ‘collagen’‘keratoconus’,‘keratectasia’,‘collagen cross-linking’,and ‘photorefractive keratectomy’. Search results were restricted to clinical studies published in English. Corneal CXL effectively arrests the progression of keratoconus by enhancing corneal rigidity. However, functional vision is not improved by cross-linking. Combining CXL to refractive surgeries such as topography-guided PRK or transepithelial PRK is found to be a safe and effective method in providing corneal stability as well as significantly improving functional visual acuity with few minor complications. This combined technique also prevents regression of keratoconus and reduce the risk of keratectasia. CXL combined with PRK is a promising therapeutic approach in ophthalmology that can be successfully used to treat progressive keratoconus and other corneal ectatic disorders and to enhance visual acuity.

关键词： corneal collagen cross-linking photorefractive keratectomy keratoconus

Deterministic and Stochastic Fractional-Order Hastings-Powell Food Chain model

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Computers, materials & Continua 2022年第2期70卷 2277-2296页

作者： moustafa El-Shahed Asmaa m.al-Dububan Department of mathematics Unaizah College of Sciences and ArtsQassim UniversityUnaizah51911Saudi Arabia Department of mathematics Buraydah College of Sciences and ArtsQassim UniversityBuraydah51431Saudi Arabia

In this paper,a deterministic and stochastic fractional-order model of the tri-trophic food chain model incorporating harvesting is proposed and *** interaction between prey,middle predator and top predator population is *** order to clarify the characteristics of the proposed model,the analysis of existence,uniqueness,non-negativity and boundedness of the solutions of the proposed model are *** sufficient conditions that ensure the local and global stability of equilibrium points are *** using stability analysis of the fractional-order system,it is proved that if the basic reproduction number R_(0)m point E_(1) is globally asymptotically *** occurrence of local bifurcation near the equilibrium points is investigated with the help of Sotomayor’s *** numerical examples are given to illustrate the theoretical *** impact of harvesting on prey and themiddle predator is *** conclude that harvesting parameters can control the dynamics of the middle predator.A numerical approximation method is developed for the proposed stochastic fractional-order model.

关键词： Food chain model global dynamics stability stochastic Hastings-Powell model harvesting

Comparative chemical sensor for detection of chromium(Ⅵ) in aqueous solution

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Optoelectronics Letters 2025年第1期21卷 21-27页

作者： Sura H.al-REKABI A.A.alWAHIB Electrical Technique Department Al Suwayrah Technical Institute Middle Technical University Laser and Optoelectronics Department University of Technology-Iraq

A process for purifying aqueous solutions containing heavy and toxic metals such as chromium（Cr） has been investigated. One of the extremely harmful pollutants in rivers and seawater is the heavy metal ions due to their direct impacts on human, animals and plants are hexavalent Cr（Ⅵ）. Consequently, highly sensitive sensor to detect Cr is essential. Surface plasmon resonance（SPR） technique has attracted huge research interest in detecting heavy metals specifically. In this study, three types of prism-based SPR sensor, gold（Au）/silver（Ag）, Au/polyaniline（PANI） and Au/titanium dioxide（TiO2） nanostructured films, are investigated as potential sensing material to detect the presence of Cr（Ⅵ） ions in water. The base Au layer with thickness of 48.3 nm is deposited on a glass slide for all sensors. For Au/Ag, Au/PANI nanofibers and Au/TiO2sensor films, the Cr（Ⅵ） concentration is varied from 1 ppm to 15 ppm with sensitivity of 0.270 °ppm-1, 0.082 °ppm-1and 0.039 °ppm-1, respectively. Based on these results, the Au/PANI nanofibers are the most sensitive to Cr（Ⅵ） among the tested sensing materials.

关键词： Titanium dioxide