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助剂对甲烷干重整 Ni/γ-Al_2O_3催化剂性能的影响(英文)

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催化学报 2011年第10期32卷 1604-1609页

作者： ahmed S.A.AL-FATeSH Anis H.FAKeeHA ahmed e.abasaeed Chemical engineering Department College of EngineeringKing Saud UniversityP.O.Box 800Riyadh 1142Saudi Arabia

The Ni catalysts supported on γ-Al2O3 were synthesized by an impregnation method.Their catalytic performance in methane dry reforming was investigated.The reforming reactions were carried out in a microreactor using a CO2:CH4 feed ratio of 1:1,a F/W = 2640 ml/(h·g),reaction temperatures between 500-850 ?C,and at atmospheric pressure.The influence of Ca,Ce,and Zr promoters on catalyst stability,coke deposition,and the H2/CO ratio were also studied.effluents were analyzed using an online gas chromatograph equipped with a thermal conductivity detector.The spent and fresh catalysts were characterized by scanning electron microscopy and thermogravimetric analysis.It was found that 3%Ni/γ-Al2O3 promoted with 0.15% Ce and 0.05% Ca gave the best performance and resulted in less coke formation.The highest CH4 and CO2 conversion activities were found to be 94.1% and 98.3% at 850 ?C,respectively.Stability tests were carried out for 130 h and this provided a H2 yield of 91%.Moreover,the amount of formed carbon was negligible and did not increase to more than 1.5 wt%.

关键词：稳定性合成气焦碳合成方法

La_2O_3助剂对甲烷干燥重整催化剂Ni-γ-Al_2O_3支撑作用的研究(英文)

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Chinese Journal of Chemical engineering 2014年第1期22卷 28-37页

作者： ahmed S.Al-Fatesh Muhammad A.Naeem Anis H.Fakeeha ahmed e.abasaeed Chemical engineering Department College of Engineering King Saud University

The nature of support and type of active metal affect catalytic performance.In this work,the effect of using La2O3 as promoter and support for Ni/γ-Al2O3 catalysts in dry reforming of methane was investigated.The reforming reactions were carried out at atmospheric pressure in the temperature range of 500-700°C.The activity and stability of the catalyst,carbon formation,and syngas(H2/CO)ratio were determined.Various techniques were applied for characterization of both fresh and used catalysts.Addition of La2O3to the catalyst matrix improved the dispersion of Ni and adsorption of CO2,thus its activity and stability enhanced.

关键词：甲烷重整 α-Al2O3 催化剂氧化镧 H2 CO 催化活性 La2O3 催化性能

exact and heuristic formulae to compute the geodetic height from the ellipse equation

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Geodesy and Geodynamics 2024年第2期15卷 150-155页

作者： Mohamed eleiche ahmed Hamdi Mansi Construction Department Faculty of EngineeringEgyptian Russian UniversityCairoEgypt Istituto Nazionale di Geofisica e Vulcanologia Sezione di PisaPisaPlItaly

The conversion of the cartesian coordinates of a point to its geodetic equivalent coordinates in reference to the geodetic ellipsoid is one of the main challenges in geodesy.The ellipse equation in the meridian plane significantly influences the value of the geodetic coordinates.This research analyzes this influence and how it can contribute to their solutions.The study investigates the mathematical relation between them and presents an exact formula relating to the geodetic height and the ellipse equation.In addition,a heuristic formula for the relation between the geodetic height and the ellipse equation is proposed,which is independent of the geodetic latitude and has a relative accuracy better than 99.9 %.The calculation is stable,and the cost is low.

关键词： ellipse equation Geodetic height Heuristic geodetic height

Phytochemical analysis, antioxidant, acetylcholinesterase, and α-amylase inhibitors from Hippeastrum hybridum extract

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Journal of Traditional Chinese Medicine 2024年第3期44卷 496-504页

作者： Naila Sher Mushtaq ahmed Nadia Mushtaq Department of Biotechnology University of Science and Technology Department of Botany University of Science and Technology

OBJeCTIVe:To investigate the effects of Hippeastrum hybridum（HH） as a free radical scavenger,and an inhibitor of the two enzymes i-e Alpha-amylase（α-amylase） and acetylcholinesterase（AChe）.MeTHODS:In this study,HH plant was preliminary analyzed for phytochemical screening and then tested for its antioxidant,anti-α-amylase,and anti-AChe efficiency via standard procedures.ReSULTS:Phytochemical analysis shows the existence of different compounds;while Coumarins and quinones were absent.The total phenolic,flavonoid,and tannins content were found to be（78.52±0.69） mg GAe/g,（2.01±0.04） mg RUe/g,and（58.12±0.23） mg TAe/g of plant extract respectively.28.02%±0.02% alkaloid and 2.02%±0.05% saponins were present in the HH extract.The HH extract showed the anti-oxidant property with IC50（50%inhibition） of（151.01±0.13）(HH),（79.01±0.04）(Ascorbic acid) for ferric reducing,（91.48±0.13）(HH),（48.02±0.11）(Ascorbic acid) against Ammonium molybdenum,（156.02±0.31）(HH),（52.38±0.21）(Ascorbic acid) against DPPH,136.01±0.21（HH）,52.02±0.31（Ascorbic acid） against H2O2,and 154.12±0.03（HH）,（40.05±0.15）(Ascorbic acid)μg/mL against ABTS respectively.Statistical analysis indicated that HH caused a competitive type of inhibition of α-amylase(Vmaxremained constant and Km increases from 10.65 to84.37%) while Glucophage caused the un-competitive type of inhibition i-e both Km and Vmaxdecreased from40.49 to 69.15%and 38.86 to 69.61%respectively.The Ki,（inhibition constant）;KI,（dissociation constant）,Km,（Michaelis-Menten constant）,and IC50 were found to be62,364,68.1,and 38.08±0.22 for HH and 12,101.05,195,34.01±0.21 for Glucophage.Similarly,HH causes an anon-competitive type of inhibition of AChe i-e Km remains constant while Vmaxdecreases from 60.5%to74.1%.The calculated Ki,KI,Km,and IC50 were found to be 32,36.2,0.05,and 18.117±0.018.CONCLUSION:From the current results,it is concluded that HH extract contains bioactive compounds,and could be a good alternative to controlling oxidants,Alzheimer‘s and Type-Ⅱ diabetic diseases.

关键词： Hippeastrum hybridum acetylcholinesterase alpha-amylase antioxidant phytochemicals

Study of scalar particles through the Klein–Gordon equation under rainbow gravity effects in Bonnor–Melvin-Lambda space-time

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Communications in Theoretical Physics 2024年第4期76卷 113-125页

作者： Faizuddin ahmed Abdelmalek Bouzenada Department of Physics University of Science&Technology MeghalayaRi-Bhoi793101India Laboratory of theoretical and applied Physics Echahid Cheikh Larbi Tebessi UniversityAlgeria

In our investigation,we explore the quantum dynamics of charge-free scalar particles through the Klein–Gordon equation within the framework of rainbow gravity,considering the Bonnor–Melvin-Lambda(BML)space-time background.The BML solution is characterized by the magnetic field strength along the axis of the symmetry direction which is related to the cosmological constantΛand the topological parameterαof the geometry.The behavior of charge-free scalar particles described by the Klein–Gordon equation is investigated,utilizing two sets of rainbow functions:(i)f(χ)=■,h(χ)=1 and(ii)f(χ)=1,h(χ)=1+βХ/2.Here 0e representing the particle's energy,ep is the Planck's energy,andβis the rainbow parameter.We obtain the approximate analytical solutions for the scalar particles and conduct a thorough analysis of the obtained results.Afterwards,we study the quantum dynamics of quantum oscillator fields within this BML space-time,employing the Klein–Gordon oscillator.Here also,we choose the same sets of rainbow functions and obtain the approximate eigenvalue solution for the oscillator fields.Notably,we demonstrate that the relativistic approximate energy profiles of charge-free scalar particles and oscillator fields get influenced by the topology of the geometry and the cosmological constant.Furthermore,we show that the energy profiles of scalar particles receive modifications from the rainbow parameter and the quantum oscillator fields by both the rainbow parameter and the frequency of oscillation.

关键词： quantum fields in curved space-time relativistic wave equations solutions of wave equations bound-state special functions

evaluating implicit gender bias at Canadian otolaryngology meetings through use of professional title

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World Journal of Otorhinolaryngology-Head and Neck Surgery 2024年第1期10卷 12-17页

作者： Kylen Van Osch Agnieszka Dzioba Khadija ahmed Andrew MacDonald Jamila Skinner Harley Williams Julie e.Strychowsky M.elise Graham Department of Otolaryngology-Head&Neck Surgery Schulich School of Medicine&DentistryWestern UniversityLondonOntarioCanada Department of Otolaryngology London Health Sciences Centre Children's HospitalLondonOntarioCanada Faculty of Medicine Schulich School of Medicine&DentistryWestern UniversityLondonOntarioCanada

Objectives:Increasing numbers of women enter medical school annually.The number of female physicians in leadership positions has been much slower to equalize.There are also well‐documented differences in the treatment of women as compared to men in professional settings.Female presenters are less likely to be introduced by their professional title(“Doctor”)for grand rounds and conferences,especially with a man performing the introduction.This study reviewed the Canadian Society of Otolaryngology–Head and Neck Surgery(CSOHNS)meetings from 2017 to 2020 to determine the proportion of presenters introduced by their professional title and whether this varied by gender.Methods:Recordings from CSOHNS meetings were reviewed and coded for introducer and presenter demographics,including leadership positions and gender.Chi‐squared tests of proportion and multivariate logistic regression was used to compare genders and identify factors associated with professional versus unprofessional forms of address.Results:No significant association was found between professional title use and introducer or presenter gender.Female presenters were introduced with professional title 69.6%of the time,while male presenters were introduced with professional title 67.6%of the time(P=0.69).Residents were introduced with a professional title with the most frequency(75.8%),while attending staff were introduced with a professional title with the least frequency(63.0%)(P=0.02).Conclusions:The lack of gender bias in speaker introductions at recent CSOHNS meetings demonstrates progress in achieving gender equity in medicine.Research efforts should continue to define additional forms of unconscious bias that may be contributing to gender inequity in leadership positions.

关键词： attitude of health personnel gender identity Otolaryngology women

Diagnostic accuracy of ePOS score in predicting DNR labeling after ICU admission:A prospective observational study(ePOS-DNR)

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Journal of Intensive Medicine 2024年第2期4卷 216-221页

作者： Omar e.Ramadan ahmed F.Mady Mohammed A.Al-Odat ahmed N.Balshi ahmed W.Aletreby Taisy J.Stephen Sheena R.Diolaso Jennifer Q.Gano Waleed Th.Aletreby Department of Critical Care King Saud Medical CityRiyadhSaudi Arabia Anesthesia Department Faculty of MedicineAin Shams UniversityCairoEgypt Anesthesia Department Faculty of MedicineTanta UniversityTantaEgypt Faculty of Medicine Alexandria UniversityAlexandriaEgypt Nursing Department King Saud Medical CityRiyadhSaudi Arabia

Background Resuscitation can sometimes be futile and making a do-not-resuscitate(DNR)decision is in the best interest of the patient.The electronic poor outcome screening(ePOS)score was developed to predict 6-month poor outcomes of critically ill patients.We explored the diagnostic accuracy of the ePOS score in predicting DNR decisions in the intensive care unit(ICU).Methods This study was conducted at the ICU of a tertiary referral hospital in Saudi Arabia between March and May 2023.Prospectively,we calculated ePOS scores for all eligible consecutive admissions after 48 h in the ICU and recorded the DNR orders.The ability of the score to predict DNR was explored using logistic regression.Youden's ideal cut-off value was calculated using the DeLong method,and different diagnostic accuracy measures were generated with corresponding 95%confidence intervals(CIs).Results We enrolled 857 patients,125 received a DNR order and 732 did not.The average ePOS score of DNR and non-DNR patients was 28.2±10.7 and 15.2±9.7,respectively.ePOS score,as a predictor of DNR order,had an area under receiver operator characteristic(AUROC)curve of 81.8%(95%CI:79.0 to 84.3,Pen's ideal cut-off value>17 was associated with a sensitivity of 87.2(95%CI:80.0 to 92.5,Pecificity of 63.9(95%CI:60.3 to 67.4,Pe predictive value of 29.2(95%CI:24.6 to 33.8,Pegative predictive value of 96.7(95%CI:95.1 to 98.3,Pe ePOS score performed well as a diagnostic test for patients who will be labeled as DNR during their ICU stay.A cut-off score>17 may help guide clinical decisions to withhold or commence resuscitative measures.

关键词： Do-not-resuscitate(DNR) Resuscitation Intensive care unit(ICU) Diagnostic accuracy Sensitivity Specificity

沸石负载Ni催化剂在甲烷干重整中的稳定性(英文)

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催化学报 2013年第4期34卷 764-768页

作者： Anis H. FAKeeHA Wasim U. KHAN ahmed S. AL‐FATeSH ahmed e. abasaeed Chemical engineering Department College of Engineering King Saud University

Ni/γ-Al2O3 , Ni/Y-zeolite, and Ni/H-ZSM-5 catalysts were prepared using the incipient wetness impregnation method. Their catalytic performance in dry reforming of methane was studied. The fresh and used catalysts and deposited carbon were characterized using H2 temperature-programmed reduction, temperature-programmed oxidation, N2 adsorption-desorption, X-ray diffraction, and thermogravimetric analysis. The H-ZSM-5-supported Ni catalyst proved to be more stable than the other two catalysts, as it had the lowest carbon deposition.

关键词： Carbon dioxide Dry reforming Methane Nickel catalyst H‐ZSM‐5 zeolite Carbon deposition

Intelligent Fractional-Order Controller for SMeS Systems in Renewable energy-Based Microgrid

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Computer Modeling in engineering & Sciences 2024年第8期140卷 1807-1830页

作者： Aadel M.Alatwi Abualkasim Bakeer Sherif A.Zaid Ibrahem e.Atawi Hani Albalawi ahmed M.Kassem electrical engineering Department Faculty of EngineeringUniversity of TabukTabuk47913Saudi Arabia Industrial Innovation and Robotic Center(IIRC) University of TabukTabuk47731Saudi Arabia Department of electrical engineering Faculty of EngineeringAswan UniversityAswan81542Egypt Renewable energy and environmental Technology Centre University of TabukTabuk47913Saudi Arabia electrical engineering Department Faculty of EngineeringSohag UniversitySohag82524Egypt

An autonomous microgrid that runs on renewable energy sources is presented in this article.It has a supercon-ducting magnetic energy storage(SMeS)device,wind energy-producing devices,and an energy storage battery.However,because such microgrids are nonlinear and the energy they create varies with time,controlling and managing the energy inside them is a difficult issue.Fractional-order proportional integral(FOPI)controller is recommended for the current research to enhance a standalone microgrid’s energy management and performance.The suggested dedicated control for the SMeS comprises two loops:the outer loop,which uses the FOPI to regulate the DC-link voltage,and the inner loop,responsible for regulating the SMeS current,is constructed using the intelligent FOPI(iFOPI).The FOPI+iFOPI parameters are best developed using the dandelion optimizer(DO)approach to achieve the optimum performance.The suggested FOPI+iFOPI controller’s performance is contrasted with a conventional PI controller for variations in wind speed and microgrid load.The optimal FOPI+iFOPI controller manages the voltage and frequency of the load.The behavior of the microgrid as a reaction to step changes in load and wind speed was measured using the proposed controller.MATLAB simulations were used to evaluate the recommended system’s performance.The results of the simulations showed that throughout all interruptions,the recommended microgrid provided the load with AC power with a constant amplitude and frequency.In addition,the required load demand was accurately reduced.Furthermore,the microgrid functioned incredibly well despite SMeS and varying wind speeds.Results obtained under identical conditions were compared with and without the best FOPI+iFOPI controller.When utilizing the optimal FOPI+iFOPI controller with SMeS,it was found that the microgrid performed better than the microgrid without SMeS.

关键词： Fractional-order proportional integral(FOPI) intelligent controller renewable energy resources superconducting magnetic energy storage optimization