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A new green process for biodiesel production from waste oils via catalytic distillation using a solid acid catalyst-Modeling, economic and environmental analysis

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Green Energy & Environment 2016年第1期1卷 62-74页

作者： Aashish Gaurav flora t.t.ng Garry L.Rempel Department of Chemical Engineering University of Waterloo

the challenges in the chemical processing industry today are environmental concerns, energy and capital costs. Catalytic distillation(CD) is a green reactor technology which combines a catalytic reaction and separation via distillation in the same distillation column. Utilization of CD in chemical process development could result in capital and energy savings, and the reduction of greenhouse gases. the efficacy of CD and the economic merits, in terms of energy and equipment savings, brought by CD for the production of biodiesel from waste oil such as yellow grease is quantified. Process flow sheets for industrial routes for an annual production of 10 million gallon AStM purity biodiesel in a conventional process(reactor followed by distillation) and CD configurations are modeled in Aspen Plus. Material and energy flows, as well as sized unit operation blocks, are used to conduct an economic assessment of each process. total capital investment, total operating and utility costs are calculated for each process. the waste oil feedstock is yellow grease containing both triglyceride and free fatty acid. Both transesterification and esterification reactions are considered in the process simulations. Results show a significant advantage of CD compared to a conventional biodiesel processes due to the reduction of distillation columns, waste streams and greenhouse gas emissions. the significant savings in capital and energy costs together with the reduction of greenhouse gases demonstrate that process intensification via CD is a feasible and new green process for the biodiesel production from waste oils.

关键词： Yellow grease Catalytic distillation Aspen plus economic analyzer Process intensification

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A kinetic model for a single step biodiesel production from a high free fatty acid (FFA) biodiesel feedstock over a solid heteropolyacid catalyst

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Green Energy & Environment 2019年第3期4卷 328-341页

作者： Aashish Gaurav Stéphane Dumas Chau t.Q.Mai flora t.t.ng Department of Chemical Engineering University of Waterloo

Production of biodiesel from yellow grease(waste cooking oil and waste animal fats) is fast emerging as a promising alternative to address the twin challenges before the biodiesel industry today-fluctuation in prices of vegetable oil and the food versus fuel debate. Yellow grease has a high percentage of free fatty acids(FFA) and proves to be an unsuitable feedstock for biodiesel production from commercially viable alkalicatalyzed production systems due to saponification problems.'Green' methodologies based on heterogeneous solid acid catalyzed reactions have the potential to simultaneously promote esterification and transesterification reactions of yellow grease to produce biodiesel without soap formation and offer easy catalyst separation without generation of toxic streams. this paper presents kinetic studies for the conversion of model yellow grease feeds to biodiesel using a heteropolyacid supported on alumina(HSiW/Al2O3) using a batch autoclave. three model yellow grease feeds were prepared using canola oil with added FFA such as palmitic, oleic and linoleic acid. A pseudo homogeneous kinetic model for the parallel esterification and transesterification was developed. the rate constants and activation parameters for esterification and transesterification reactions for the model yellow grease feeds were determined. the rate constants for esterification are higher than the transesterification rate constants. the kinetic model was validated using the experimental biodiesel data obtained from processing a commercial yellow grease feed. the kinetic model could be used to design novel processes to convert various low-value waste oils, fats and non-food grade oils to sustainable biodiesel.

关键词： Yellow grease Canola oil Free fatty acids Heteropolyacid Kinetics for esterification and transesterification

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二苯并噻吩在分散型钼催化剂和原位产生的氢存在下的加氢脱硫Ⅳ. 集总动力学(英)

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催化学报 1999年第6期20卷 597-602页

作者：刘晨光黄春城石油大学(华东)炼制系重质油加工国家重点实验室山东东营257062 加拿大滑铁卢大学化工系

研究了水／甲苯乳化液中二苯并噻吩（硫芴）在分散型钼酸、磷钼酸和四硫代钼酸铵催化剂存在下的加氢脱硫反应．反应在高压釜中于３４０ ℃及三种不同的气氛即Ｈ２，Ｈ２／Ｈ２Ｏ和ＣＯ／Ｈ２Ｏ（ＣＯ和Ｈ２Ｏ经水煤气转换反应... 详细信息

研究了水／甲苯乳化液中二苯并噻吩（硫芴）在分散型钼酸、磷钼酸和四硫代钼酸铵催化剂存在下的加氢脱硫反应．反应在高压釜中于３４０ ℃及三种不同的气氛即Ｈ２，Ｈ２／Ｈ２Ｏ和ＣＯ／Ｈ２Ｏ（ＣＯ和Ｈ２Ｏ经水煤气转换反应（ＷＧＳＲ）产生原位氢）的存在下进行．用ＧＣ和ＧＣＭＳ鉴定、分析了气体和液体产物的组成．在此基础上，提出了包含直接氢解和加氢脱硫两个反应途径的硫芴加氢反应网络，并采用最优化法计算了反应网络的速率常数．结果表明：对所研究的９个反应体系，反应网络的模型预测值与试验值十分吻合；加氢路径比氢解路径至少快１倍，硫芴的加氢比联苯的加氢快１倍，部分加氢的中间产物１，２，３，４四氢硫芴和１，２，３，４，１０，１１六氢硫芴的氢解比硫芴直接氢解快１０倍以上；对硫芴的加氢脱硫反应，在分散型钼存在下，原位产生的氢比加入的氢气更为有效．

关键词：加氢脱硫分散型催化剂脱硫钼二苯并噻吩

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Mitochondrial therapeutics and mitochondrial transfer for neurodegenerative diseases and aging

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Neural Regeneration Research 2025年第3期20卷 794-796页

作者： Neville ng Michelle Newbery Nicole Miles Lezanne Ooi Molecular Horizons and School of Chemistry and Molecular Bioscience University of WollongongWollongongNSWAustralia

Mitochondrial dysfunction and neurodegeneration:Progressive neurodegenerative diseases affect a significant proportion of the population;in a single year,there are as many as 276 million disabilities and 9 million dea... 详细信息

关键词： degenerative diseases Mitochondrial

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Robust interface and excellent as-built mechanical properties of ti–6Al–4V fabricated through laser-aided additive manufacturing with powder and wire

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International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 154-168页

作者： Fei Weng Guijun Bi Youxiang Chew Shang Sui Chaolin tan Zhenglin Du Jinlong Su Fern Lan ng Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials Ministry of EducationShandong Engineering&Technology Research Center for Superhard MaterialSchool of Materials Science and EngineeringShandong UniversityJinan 250061China Institute of Intelligent Manufacturing Guangdong Academy of SciencesGuangzhou 510095China Singapore Institute of Manufacturing technology 5 Cleantech Loop636732Singapore

the feasibility of manufacturing ti-6Al-4V samples through a combination of laser-aided additive manufacturing with powder(LAAM_(p))and wire(LAAM_(w))was explored.A process study was first conducted to successfully circumvent defects in ti-6Al-4V deposits for LAAM_(p) and LAAM_(w),*** the optimized process parameters,robust interfaces were achieved between powder/wire deposits and the forged substrate,as well as between powder and wire *** characterization results revealed the epitaxial prior β grains in the deposited ti-6Al-4V,wherein the powder deposit was dominated by a finerα′microstructure and the wire deposit was characterized by lamellar α *** mechanisms of microstructure formation and correlation with mechanical behavior were analyzed and *** mechanical properties of the interfacial samples can meet the requirements of the relevant Aerospace Material Specifications(AMS 6932)even without post heat *** fracture occurred within the interfacial area,further suggesting the robust *** findings of this study highlighted the feasibility of combining LAAM_(p) and LAAM_(w) in the direct manufacturing of ti-6Al-4V parts in accordance with the required dimensional resolution and deposition rate,together with sound strength and ductility balance in the as-built condition.

关键词： laser-aided additive manufacturing powder deposition wire deposition interfacial characteristic mechanical behavior

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Impact of Pollutant Concentration and Particle Deposition on the Radiative Flow of Casson-Micropolar Fluid between Parallel Plates

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Computer Modeling in Engineering & Sciences 2025年第1期142卷 665-690页

作者： Ghaliah Alhamzi Badr Saad t.Alkahtani Ravi Shanker Dubey Vinutha Kalleshachar Neelima Nizampatnam Department of Mathematics and Statistics College of ScienceImam Mohammad Ibn Saud Islamic University(IMSIU)Riyadh11564Saudi Arabia Department of Mathematics College of ScienceKing Saud UniversityRiyadh11989Saudi Arabia Department of Mathematics Amity School of Applied SciencesAmity University RajasthanJaipur302002RajasthanIndia Department of Studies in Mathematics Davangere UniversityDavangere577002India Department of Electronics and Communication Engineering Amrita School of EngineeringAmrita Vishwa VidyapeethamBengaluru560035India

Assessing the behaviour and concentration of waste pollutants deposited between two parallel plates is essential for effective environmental *** the effectiveness of treatment methods in reducing pollution scales is made easier by analysing waste discharge *** waste discharge concentration analysis is useful for assessing how effectively wastewater treatment techniques reduce pollution *** study aims to explore the Casson micropolar fluid flow through two parallel plates with the influence of pollutant concentration and thermophoretic particle *** explore the mass and heat transport features,thermophoretic particle deposition and thermal radiation are *** governing equations are transformed into ordinary differential equations with the help of suitable similarity *** Runge-Kutta-Fehlberg’s fourthfifth order technique and shooting procedure are used to solve the reduced set of equations and boundary *** integration of a neural network model based on the Levenberg-Marquardt algorithm serves to improve the accuracy of predictions and optimize the analysis of *** outcomes are displayed to analyze the characteristics of the relevant dimensionless parameters in the current *** reveal that concentration upsurges as the micropolar parameter *** concentration reduces with an upsurge in the thermophoretic *** upsurge in the external pollutant source variation and the local pollutant external source parameters enhances mass *** surface drag force declines for improved values of porosity and micropolar parameters.

关键词： Micropolar fluid thermal radiation porous medium thermophoretic particle deposition waste discharge concentration

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transport mechanism in chemically reactive hybrid nanofluid flow containing gyrotactic micro-organisms over a curved oscillatory surface

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Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 177-192页

作者： M.NAVEED M.IMRAN t.ASGHAR Z.ABBAS Department of Mathematics Division of Science and TechnologyUniversity of Education Department of Mathematics The Islamia University of Bahawalpur

this paper examines the transport analysis, including both heat transfer and mass transfer, in hybrid nanofluid flow containing gyrotactic microorganisms towards a curved oscillatory surface. the influence of magnetic fields is also inspected in terms of their physical characteristics. to depict the phenomena of transport, modified versions of both Fick's and Fourier's laws are used. Additionally, the characteristics of both heterogeneous and homogeneous chemical reactions are also incorporated. Utilizing a curvilinear coordinate system, the flow problem is formulated as partial differential equations(PDEs)for momentum, concentration, microorganism field, and energy. An analytical solution to the obtained flow equations is achieved utilizing the homotopy analysis method(HAM).the effects of significant flow parameters on the pressure and microorganism fields, velocity, oscillation velocity, concentration, and temperature distributions are shown via graphs. Furthermore, the variations in skin friction, mass transfer rate, heat transfer rate, and local motile number due to different involved parameters are presented in tables and are analyzed in detail. Graphical results indicate that the curves of velocity and temperature fields are enhanced as the values of the solid volume fraction variables *** is also verified that the concentration rate field decreases as the values of the homogeneous reaction strength parameter and the radius of curvature parameter increase, and it increases with the Schmidt number and the heterogeneous reaction strength *** outcomes show a favorable response of the motile number to advanced values of the Peclet number, the Schmidt number, the microorganism difference parameter, and the bio-convective Lewis number.

关键词： Peclet number

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the impact of alpha-fetoprotein(AFP),child-turcotte-pugh(CtP)score and disease staging on the survival of hepatocellular carcinoma(HCC)patients:a retrospective cohort from single oncology center

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Oncology Research 2025年第1期33卷 149-160页

作者： NASSER MULLA YOUSEF KAtIB ASIM M.ALMUGHAMSI DUAA S.ALKHAYAt MOHAMED MOSAAD SAMIR t.ALFOtIH RAWAN ALAOFI Department of Internal Medicine Faculty of MedicineTaibah UniversityMadinah42278Saudi Arabia Department of Radiology Faculty of MedicineTaibah UniversityMadinah42278Saudi Arabia Department of Surgery Faculty of MedicineTaibah UniversityMadinah42278Saudi Arabia Department of Endemic and Infectious Diseases Suez Canal UniversityIsmailia41522Egypt King Salman bin Abdulaziz Medical City Madinah42311Saudi Arabia Prince Mohammed Bin Abdulaziz Hospital Madinah41511Saudi Arabia

Background:Hepatocellular carcinoma(HCC)is the most common cause of cancer-related death in Saudi *** study aimed to investigate the patterns of HCC and the effect of tNM staging,Alfa-fetoprotein(AFP),and Child-turcotte Pugh(CtP)on patients’overall survival(OS).Methods:A retrospective analysis was conducted on 43 HCC patients at a single oncology center in Saudi Arabia from 2015 to *** patients had to fulfill one of the following criteria:(a)a liver lesion reported as definitive HCC on dynamic imaging and/or(b)a biopsy-confirmed ***:the mean patient age of all HCC cases was 66.8 with a male-to-female ratio of 3.3:*** patients were stratified into two groups:viral HCC(n=22,51%)and non-viral HCC(n=21,49%).Among viral-HCC patients,55%were due to HBV and 45%due to *** was diagnosed in 79%of *** and sex did not significantly statistically differ in OS among viral and non-viral HCC patients(p-value>0.05).About 65%of patients had tumor size>5 cm during the diagnosis,with a significant statistical difference in OS(p-value=0.027).AFP was>400 ng/ml in 45%of the *** was a statistically significant difference in the OS in terms of AFP levels(p-value=0.021).A statistically significant difference was also observed between the CtP score and OS(p-value=0.02).CtP class B had the longest *** was the most common treatment provided to HCC patients followed by sorafenib *** was a significant statistical difference in OS among viral and non-viral HCC patients(p-value=0.008).Conclusions:the most common predictors for OS were the underlying cause of HCC,AFP,and tumor *** having non-viral etiology,a tumor size>5 cm,an AFP>400 ng/mL,and a CtP score class C were all negatively associated with OS.

关键词： Hepatocellular carcinoma Pattern Alpha-fetoprotein(AFP) Child-turcotte-pugh Progression free survival

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Free vibration and transient response of double curved beams connected by intermediate straight beams

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Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 37-62页

作者： R.A.JAFARI-tALOOKOLAEI H.GHANDVAR E.JUMAEV S.KHAtIR t.CUOng-LE School of Mechanical Engineering Babol Noshirvani University of Technology Department of Mechanical Engineering Faculty of Engineering New Uzbekistan University University of Business and Science Center for Engineering Application and technology Solutions Ho Chi Minh City Open University

this paper investigates the free vibration and transient response of interconnected structures including double curved beams and intermediate straight beams,which are all constructed from functionally graded porous(FGP) materials. the strain potential and kinetic energies of each beam along with the work done by the external force are calculated. Additionally, a higher-order beam element is introduced to derive stiffness and mass matrices, along with the force vector. the curved and straight beams are discretized, and their assembled stiffness, mass matrices, and force vectors, are *** conditions at the joints are used to derive the total matrices of the entire structure. Subsequently, the natural frequencies and transient response of the system are determined. the accuracy of the mathematical model and the self-developed computer program is validated through the comparison of the obtained results with those of the existing literature and commercial software ANSYS, demonstrating excellent ***, a comprehensive study is conducted to investigate the effects of various parameters on the free vibration and transient response of the considered structure.

关键词： Kinetic energy

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Calibration of the Solar X-ray Detector on-board the Macao Science Satellite-1B for Soft X-ray Detection

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Science China Earth Sciences 2025年第1期68卷 11-26页

作者： Man-Hei ng Xiaoping ZHAng Jianwu CHEN Yongqiang SHI Fuchang ZUO Wenxi PEng Weichun FU Liansheng LI Pengwei LUO Chi-Long tAng Guozheng ZHAng Zhiwu MEI Li WAng Cunhui LI Jiaming OU Yanyan XU State Key Laboratory of Lunar and Planetary Sciences Macau University of Science and Technology China National Space Administration (CNSA) Macau Center for Space Exploration and Science Space Optoelectronic Measurement and Perception Laboratory Beijing Institute of Control Engineering Institute of High Energy Physics Chinese Academy of Sciences Science and technology on Vacuum technology and Physics Laboratory Lanzhou Institute of Physics

the Solar X-ray Detector(SXD) on-board the Macao Science Satellite-1B(MSS-1B) was successfully launched via the Chinese Long March-2C rocket on 21 May 2023, and commenced operations in early June of the same year. the MSS-1B/Soft X-ray Detection Units(SXDUs) employ two silicon drift detectors(SDDs), providing a wide range of energy spectra spanning from 0.7 to 24 keV. Notably, the SXDUs deliver a high-resolution capability of 0.14 keV@5.9 keV and operate with a time cadence of 1 second. Here, we perform thorough calibrations of the MSS-1B/SXDUs, employing a combination of ground experiments and simulations. In addition, quantitative analysis comparing the flux measurements obtained by the MSS-1B/SXDUs to the data collected by the Geostationary Operational Environmental Satellite(GOES), provides compelling evidence of their consistency. Furthermore, the preliminary spectral analysis results showcase the robustness and expected performance of the MSS-1B/SXDUs, unlocking their potential for facilit.t.ng the study of dynamic evolution of solar flares. Moreover, the innovative MSS-1B/Solar X-ray Detector facilitates concurrent observations of solar soft and hard X-rays, thereby making valuable contributions to the advancements in solar research.

关键词： Macao Science Satellite-1B (MSS-1B) Calibration Solar X-Ray Detector Spectrometer Soft X-rays Solar flares Solar abundances

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