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Heat Transfer Enhancement of an Automobile Engine Radiator using ZnO Water Base Nanofluids

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Journal of Thermal Science 2020年第4期29卷 1010-1024页

作者： muhammad QASIM muhammad SAJID KAMRAN muhammad ammar muhammad ALI JAMAL muhammad YASAR JAVAID Department of Mechanical Engineering University of Engineering and TechnologyLahore 54890Pakistan Department of Chemical Engineering Technology Government College UniversityFaisalabad 38000Pakistan Department of Mechanical Engineering Technology Government College UniversityFaisalabad 38000Pakistan

In this research paper, the forced convective heat transfer enhancement of a Suzuki Mehran(VXR) 2016 radiator(heat exchanger) along with pressure drop and friction factor by utilizing Zinc oxide(Zn O) water based nanofluids has been experimentally studied. Three types of nanofluids with different volumetric concentrations of Zn O nanoparticles(0–0.3%) were employed in order to understand its effect on heat transfer enhancement. The experimental setup was completely designed as closely as possible to the car cooling system. The experimentation has been done under laminar flow conditions(186≤Re≤1127) at different fluid volume flow rates(2–12 L/min) and constant fluid inlet temperature(70°C) to the automobile radiator. A maximum enhancement in heat transfer rate, overall heat transfer coefficient and Nusselt number was obtained up to 41%, 50% and 31% by using nanofluid with 0.2% volumetric concentration of nanoparticles respectively. On the other hand, the mean enhancement in pressure drop and friction factor was obtained up to 47% and 46% by using nanofluid with the same volumetric concentration of nanoparticles i.e. 0.2% respectively. The experimental results also revealed that the heat transfer rate, overall heat transfer coefficient and Nusselt number of nanofluids increases by increasing the volume flow rates and volumetric concentration of nanoparticles. However, these thermal performance parameters of nanofluids started to decline when the volumetric concentration of nanoparticles was increased from 0.2% to 0.3%. Furthermore, pressure drop and friction factor of nanofluids increase by increasing the volumetric concentration of nanoparticles, while pressure drop increases and friction factor decreases by increasing the volume flow rate of nanofluids respectively. At the end, the thermal efficiency of automobile radiator with high cooling rates was obtained by using nanofluid with 0.2% volumetric concentration of nanoparticles.

关键词： ZnO nanoparticles heat transfer enhancement thermal efficiency automobile radiator

Fe-Promoted Copper Oxide Thin-Film Catalysts for the Catalytic Reduction of N_(2)O in the Presence of Methane

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Journal of Thermal Science 2023年第2期32卷 531-541页

作者： muhammad Waqas WU Lingnan EI KASMI Achraf muhammad ammar TIAN Zhenyu Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Department of Mechanical Engineering College of Engineering and TechnologyUniversity of SargodhaSargodha 40100Pakistan Laboratory LSIA UAE/U02ENSAHNational School of Applied Sciences of Al HoceimaAbdelmalek Essaadi UniversityAl Hoceima 32003Morocco Department of Chemical Engineering Technology Government College UniversityFaisalabad 38000Pakistan

Thin-film catalysts are recently recognized as promising catalysts due to their reduced amount of materials and good catalytic activity,leading to low-cost and high-efficiency catalysts.A series of CuFeO_(x)thin-film catalysts were prepared with different Fe contents using a one-step method as well as tested for the catalytic reduction of nitrous oxide(N_(2)O)in the presence of CH_(4)at a high GH SV of 185000 mL/(g·h).The increase of iron strongly affects the dispersion and leads to the creation of a less-active segregated Fe_(2)O_(3)phase,which was confirmed by XRD,EDX,and XPS *** results show that the synergistic properties between Cu and Fe,which affect the CuFeOxfilm catalysts in many aspects,such as the hollow-like texture,specific surface area,nano-crystallite size,the surface contents of Cu^(+),Fe^(3+),and oxygen species,the reductive strength and the strong active sites on the *** DFT calculations,the adsorption and decomposition energy profiles of N_(2)O on the CuFeO_(2)(012)surface model were *** surface Fe-site and hollow-site are active for N_(2)O decomposition,and the decomposition energy barriers on the Fe-site and the hollow-site are 1.02 eV and 1.25 eV respectively at 0 *** strategy adopted here to tailor the activity through low-doping Fe-oxide catalysts could establish a promising way to improve the catalytic reduction of N_(2)O with CH_(4).

关键词： catalytic reduction thin-film catalysts doping strategy density functional theory calculations N_(2)O decomposition

An efficient green route for hexamethylene-1,6-diisocyanate synthesis by thermal decomposition of hexamethylene-1,6-dicarbamate over Co3O4/ZSM-5 catalyst： An indirect utilization of CO2

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Chinese Journal of Chemical Engineering 2017年第12期25卷 1760-1770页

作者： muhammad ammar Yan Cao Peng He Liguo Wang Jiaqiang Chen Huiquan Li Key Laboratory of Green Process and Engineering National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology Institute of Process Engineering CAS Beijing 100190 China University of Chinese Academy of Sciences Beijing 100049 China

The utilization of CO2 as raw material for chemical synthesis has the potential for substantial economic and green benefits. Thermal decomposition of hexamethylene-1,6-dicarbamate （HDC） is a promising approach for indirect utilization of CO2 to produce hexamethylene-1,6-diisocyanate （HDI）. In this work, a green route was developed for the synthesis of HD1 by thermal decomposition of HDC over Co3O4/ZSM-5 catalyst, using chlorobenzene as low boiling point solvent. Different metal oxide supported catalysts were prepared by incipient wetness impregnation （IWI）, PEG-additive （PEG） and deposition precipitation with ammonia evaporation （DP） methods. Their catalytic performances for the thermal decomposition of HDC were tested. The catalyst screening results showed that Co3O4/ZSM-525 catalysts prepared by different methods showed different performances in the order of Co3O4/ZSM-5 25（PEG）〉 Co3O4/ZSM-525（IWI）〉 Co3O4/ZSM-525（DP）. The physicochemical properties of Co3O4/ZSM- 52s catalyst were characterized by XRD, FTIR, N2 adsorption-desorption measurements, NH3-TPD and XPS. The superior catalytic performance of Co3O4/ZSM-52S（PEG） catalyst was attributed to its relative surface content of Co3 ＋, surface lattice oxygen content and total acidity. Under the optimized reaction conditions： 6.5% HDC concentration in chlorobenzene, 1 wt% Co3O4/ZSM-525（PEG） catalyst, 250℃ temperature, 2.5 h time, 800 *** 1 nitrogen flow rate and 1.0 MPa pressure, the HDC conversion and HDI yield could reach 100% and 92.8% respectively. The Co3O4/ZSM-525（PEG） catalyst could be facilely separated from the reaction mixture, and reused without degradation in catalytic performance. Furthermore, a possible reaction mechanism was proposed based on the physicochemical properties of the Co3O4/ZSM-5 25 catalysts.

关键词： Hexamethylene-1 6-dicarbamate (HDC)Hexamethylene-1 6-diisocyanate (HDI) Thermal decomposition Co3O4/ZSM-5 Heterogeneous catalyst

Non-phosgene synthesis of hexamethylene-1,6-diisocyanate from thermal decomposition of hexamethylene-1,6-dicarbamate over Zn–Co bimetallic supported ZSM-5 catalyst

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Chinese Journal of Chemical Engineering 2019年第3期27卷 549-555页

作者： Yan Cao Yafang Chi ammar muhammad Peng He liguo Wang Huiquan Li CAS Key Laboratory of Green Process and Engineering Institute of Process Engineering Chinese Academy of Sciences National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology Institute of Process Engineering Chinese Academy of Sciences University of Chinese Academy of Sciences

A non-phosgene route for the synthesis of hexamethylene-1,6-diisocyanate(HDI) was developed via catalytic decomposition of hexamethylene-1,6-dicarbamate(HDC) over Zn–Co bi-metallic supported ZSM-5 *** catalyst was characterized by FTIR and XRD analyses. Three solvents dioctyl sebacate(DOS), dibutyl sebacate(DBS) and 1-butyl-3-methylimidazolium tetrafluoroborate(BMIMBF_4) were investigated and compared; DOS gave better performance. The catalytic performances for thermal decomposition of HDC to HDI using DOS as solvent were then investigated, and the results showed that, under the optimized reaction conditions, i.e.,10 wt%concentration of HDC in DOS, 250 °C temperature, 60 min reaction time, 83.8% yield of HDI had been achieved over Zn–Co/ZSM-5. Decomposition of the intermediate hexamethylene-1-carbamate-6-isocyanate(HMI) over Zn–Co/ZSM-5 in DOS solvent was further studied and the results indicated that yield of HDI from HMI reached to 69.6%(98.6% HDI selectively) at 270 °C, which further increased the yield of the total HDI(HDI_(tol)) to as high as 95.0%. Recycling of catalyst showed that HDI and HMI yield slightly decreased, and by-product yield increased after the catalyst was reused for 4 times. At last possible reaction mechanism was proposed.

关键词： Non-phosgene Thermal decomposition Hexamethylene-1,6-diisocyanate Hexamethylene-1,6-dicarbamate Bimetallic supported ZSM-5 catalyst

Synthesis of Zeolite Imidazolate Frameworks Mateuial and Used as an Efficient Heterogeneous Catalyst for Various Chemical Reactions

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Synthesis of Zeolite Imidazolate Frameworks Mateuial and Use...

作者： muhammad ammar（阿马尔）北京化工大学

学位级别：硕士

The porous material is a significant segment of the economy, it is in general consideration to develop and design porous material to have versatile properties such as well-defined structure, tunable pore size, high porosity and highly thermal and chemical stability to perform different type of commercial and industrial applications. For last couple of decades, there is lot of effects has been done to discover and explore new porous materials. Metal organic frameworks (MOFs) materials attained much more interest due to their extraordinary structures and properties with their capability for different applications. In his research work, we selected Zeolite Imidazole Frameworks (ZIFs) materials which possess crystal structure like zeolite materials, is a type of MOFs materials. We focused on the synthesis of ZIF-67, heteropoly acid encapsulated into ZIF-67cage and ZIF-8materials and give their applications in the Friedel-Crafts acylation reactions as an efficient heterogeneous catalyst.Initially, this work demonstrated the synthesis of ZIF-67materials which containing cobalt as metal ions and2-methylimidazole as ligand, triethylamine is used as deprotonated the ligand. ZIF-67is synthesized with different metal:ligand:TEA molar ratios along with metal:ligand ratio at room temperature. Various characterization techniques are utilized such as X-ray powder diffraction abbreviated as XRD, Fourier transform infrared spectroscopy abbreviated as FT-IR, Scanning electron microscopy abbreviated as SEM, Nitrogen adsorption-desorption as well as Thermo-gravimetric analysis (TGA) to explore the characteristics of synthesized ZIF-67samples. The catalytic performance of synthesized ZIF-67is investigated in Friedel-Crafts (FC) acylation reaction of anisole by means of benzoyl chloride as acylating agent. The performance of ZIF-67(metal:ligand molar ratio1:8) sample as catalyst is found better as compare to other ZIF-67samples which involve TEA as deprotonated the ligand.45%conversi

关键词： Metal Organic Framework Zeolite ImidazolateFramework (ZIF-8) Zeolite Imidazolate Framework (ZIF-67) Friedel-Crafts acylation Phosphotungstic acid Catalytic performance

Diagnostically untypable hepatitis C virus variants:It is time to resolve the problem

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World Journal of Gastroenterology 2014年第46期20卷 17690-17692页

作者： muhammad Sohail Afzal muhammad Yousaf Khan muhammad ammar Sadia Anjum Najm us Sahar Sadaf Zaidi Atta Ur Rahman School of Applied Biosciences National University of Science and TechnologyIslamabad 44000Pakistan Genomic Research Labs and Diagnostics Center Rawalpindi 46000Pakistan

Pakistan is a low income country with more than 10 million hepatitis C virus (HCV) infections and the burden is on continuous raise. Accurate viral genotyping is very critical for proper treatment of the infected individuals as the sustained virological response of the standard antiviral interferon therapy is genotype dependent. We observed at our diagnostic center that 15.6% of HCV patient’s samples were not genotype-able by using Ohno et al method. The genotyped samples showed that 3a (68.3%) is the major prevalent genotype in Pakistan followed by 2a (10.3%), 3b (2.6%), 1b (1.5%), 2b (1.2%) and 1a (0.5%). Presence of large number of untypable HCV variants in the current study highlights an important issue of health care setup in Pakistan. Untypable HCV cases create difficulties in treatment of these patients. The problem of routine diagnostics setup of Pakistan should be addressed on priority basis to facilitate the medical professionals in patient’s treatment and to help in achieving the maximum sustained virological response.

关键词： Hepatitis C virus Genotypes Diagnostics Untypable variants Antiviral interferon therapy Pakistan

Defocus blur detection using novel local directional mean patterns(LDMP)and segmentation via KNN matting

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Frontiers of Computer Science 2022年第2期16卷 110-122页

作者： Awais KHAN Aun IRTAZA Ali JAVED Tahira NAZIR Hafiz MALIK Khalid Mahmood MALIK muhammad ammar KHAN Department of Computer Science University of Engineering and TechnologyTaxila 47050Pakistan Department of Electrical and Computer Engineering University of MichiganDearbornMI 48128USA Department of Software Engineering University of Engineering and TechnologyTaxila 47050Pakistan Department of Computer Science and Engineering Oakland UniversityMI 48309USA

Detection and segmentation of defocus blur is a challenging task in digital imaging applications as the blurry images comprise of blur and sharp regions that wrap significant information and require effective methods for information *** defocus blur detection and segmentation methods have several limitations i.e.,discriminating sharp smooth and blurred smooth regions,low recognition rate in noisy images,and high computational cost without having any prior knowledge of images i.e.,blur degree and camera ***,there exists a dire need to develop an effective method for defocus blur detection,and segmentation robust to the above-mentioned *** paper presents a novel features descriptor local directional mean patterns(LDMP)for defocus blur detection and employ KNN matting over the detected LDMP-Trimap for the robust segmentation of sharp and blur *** argue/hypothesize that most of the image fields located in blurry regions have significantly less specific local patterns than those in the sharp regions,therefore,proposed LDMP features descriptor should reliably detect the defocus blurred *** fusion of LDMP features with KNN matting provides superior performance in terms of obtaining high-quality segmented regions in the ***,the proposed LDMP features descriptor is robust to noise and successfully detects defocus blur in high-dense noisy *** results on Shi and Zhao datasets demonstrate the effectiveness of the proposed method in terms of defocus blur *** and comparative analysis signify that our method achieves superior segmentation performance and low computational cost of 15 seconds.

关键词： defocus blur detection local directional mean patterns image matting sharpness metrics blur segmentation

1-MCP Regulates Ethanol Fermentation and GABA Shunt Pathway Involved in Kiwifruit Quality During Postharvest Storage

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Horticultural Plant Journal 2021年第1期7卷 23-30页

作者： Maratab Ali muhammad ammar Raza Shenge Li Lichao Zhou Chen Huan Shen Shuling Xiaolin Zheng College of Food Science and Biotechnology Key Laboratory of Fruits and Vegetables Postharvest and Processing Technology Research of Zhejiang ProvinceZhejiang Gongshang UniversityHangzhou 310018China National Institute of Food Science and Technology Faculty of FoodNutrition and Home SciencesUniversity of AgricultureFaisalabad 38800Pakistan Fruit Professional Cooperative of Huaji Shan in Linhai City LinhaiZhejiang 317000China

Kiwifruit(Actinidia deliciosa)‘Bruno’is prone to accumulate ethanol rapidly after respiratory climacteric during storage at ambient conditions without stresses,which causes quality deterioration of the fruit associated with alcohol *** maintaining the postharvest quality of kiwifruit‘Bruno’,the effects of 1.0μL•L^−11-methylcyclopropene(1-MCP)treatment on regulating the ethanol fermentation andγ-aminobutyric acid(GABA)shunt pathway associated with control of alcohol off-flavor were investigated during storage at room temperature(24±1)°C for 27 *** results showed that 1-MCP treatment significantly reduced the respiration rate,ethylene production,decay rate,ascorbic acid(AsA)loss,and delayed the decline in the firmness and titratable acidity(TA),and the increase in total soluble solid(TSS)in ***,1-MCP treatment effectively inhibited the increases in contents of acetaldehyde,ethanol,and GABA along with the suppressed activities of key enzymes involved in ethanol fermentation and GABA shunt pathway,such as pyruvate decarboxylase(PDC),alcohol dehydrogenase(ADH),glutamate decarboxylase(GAD),and GABA-transaminase(GABA-T)in kiwifruit during *** conclusion,1-MCP treatment efficiently regulated the ethanol fermentation and GABA shunt pathway by delaying the ripening process to avoid the alcohol off-flavor development,thereby contributed to maintaining the quality of the kiwifruit.

关键词： kiwifruit ethanol fermentation GABA shunt pathway 1-methylcyclopropene quality

The adsorption properties of NaY zeolite for separation of ethylene glycol and 1,2-butanediol: Experiment and molecular modelling

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Green Energy & Environment 2021年第1期6卷 102-113页

作者： Pei Xiong Peng He Yixin Qu Liguo Wang Yan Cao Shuang Xu Jiaqiang Chen muhammad ammar Huiquan Li College of Chemical Engineering Beijing University of Chemical TechnologyBeijing100029China CAS Key Laboratory of Green Process and Engineering National Engineering Laboratory for Hydrometallurgical Cleaner Production TechnologyInstitute of Process EngineeringChinese Academy of SciencesBeijing100190China Sino-Danish Colleg5 University of Chinese Academy of SciencesBeijing100049China Sino-Danish Center for Education and Research University of Chinese Academy of SciencesBeijing10049China School of Chemical Engineering University of Chinese Academy of SciencesBeijing100049China Dalian National Laboratory for Clean Energy Dalian116023China Department of Chemical Engineering Technology Government College UniversityFaisalabad 38000Pakistan

The separation of ethylene glycol(EG)and 1,2-butanediol(1,2-BDO)azeotrope in the synthesis process of EG via coal and biomass is becoming of increasing commercial and environmental *** adsorption is deemed as the most promising methods because of energy saving and environment *** this paper,NaY zeolite was used to separate 1,2-BDO from EG,and its adsorption properties was then *** isotherms of EG and 1,2-BDO in vapor and liquid phases from 298 to 328 K indicated that they fitted Langmuir model quite well,and the NaY zeolite absorbent favored EG more than 1,*** Grand Canonical Monte Carlo(GCMC)and molecular dynamics(MD)simulation techniques were conducted to investigate the competition adsorption and diffusion characteristics in different adsorption *** was observed that EG and 1,2-BDO molecules all have the most probable locations of the center of the 12-membered ring near the Na *** diffusivities of EG are lower than those of 1,2-BDO at the same adsorption *** last,the breakthrough curves of the binary mixture regressed from the empirical Dose–Response model in fixed-bed column showed that the adsorption selectivity of EG could reach to as high as 2.43,verified that the NaY zeolite could effectively separate EG from 1,*** work is also helpful for further separation of other dihydric alcohol mixtures from coal and biomass fermentation.

关键词： Adsorption mechanism Ethylene glycol(EG) 1,2-Butanediol(1,2-BDO) NaY zeolite Fixed-bed column tests