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98篇 您的检索式:作者名="Muhammad Zafar"
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1Biosorption characteristics of unicellular green alga Chlorella sorokiniana immobilized in loofa sponge for removal of Cr(Ⅲ)显示文摘Loofa sponge(LS)immobilized biomass of Chlorella sorokiniana(LSIBCS),isolated from industrial wastewater,was investigated as a new biosorbent for the removal of Cr(Ⅲ)from aqueous solution.A comparison of the biosorption of Cr(Ⅲ)by LSIBCS and free biomass of C.sorokiniana(FBCS)from 10-300 mg Cr(Ⅲ)/L aqueous solutions showed an increase in uptake of 17.79% when the rnicroalgal biomass was immobilized onto loofa sponge.Maximum biosorption capacity for LSIBCS and FBCS was found to be 69.26 and 58.80 mg Cr(Ⅲ)/g biosorbent,respectively,whereas the amount of Cr(Ⅲ)ions adsorbed onto naked LS was 4.97 mg/g.The kinetics of Cr(Ⅲ)biosorption was extremely rapid and equilibrium was established in about 15 and 20 min by LSIBCS and FBCS, respectively.The biosorption equilibrium was well defined by Langrnuir adsorption isotherm model.The biosorption kinetics followed the pseudo-second order kinetic model.The biosorption was found to be pH dependent and the maximum sorption occurred at the solution pH 4.0.Desorption studies showed that 98% of the adsorbed Cr(Ⅲ)could be desorbed with 0.1 mol/L HNO_3,while other desorbing agents were less effective in the order:EDTA>H_2SO_4>CH_3COOH>HCl.The regenerated LSIBCS retained 92.68% of the initial Cr(Ⅲ)binding capacity up to five cycles of reuse in continuous flow-fixed bed columns.The study revealed that LSIBCS could be used as an effective biosorbent for the removal of Cr(Ⅲ)from wastewater.AKHTAR Nasreen IQBAL Muhammad ZAFAR Saeed Iqbal IQBAL Javed 2008Journal of Environmental Sciences2008,20,2:20
2山银花化学成分与其生物活性的研究进展(英文)显示文摘山银花作为中国传统中药,在中国有数千年历史。目前,山银花在湖南省有广泛栽培,主要作为清热药和消毒药应用。山银花主要包括咖啡酸衍生物、挥发油、黄酮类化合物、环烯醚萜苷和萜类化合物,主要有抗炎、抗肿瘤、抗氧化、抗过敏、免疫调节及抗菌活性等。本文通过查阅相关文献,对山银花的化学成分及其生物活性进行了全面的系统总结。汤嫣然 曾婷 Salman zafar 袁汉文 李斌 彭彩云 王思成 翦雨青 覃艳 Muhammad Iqbal Choudhary 王炜 2018Digital Chinese Medicine2018,1,2:17
3Advances in fabrication of ceramic corundum abrasives based on sol–gel process显示文摘Corundum abrasives with good chemical stability can be fabricated into various free abrasives and bonded abrasive tools that are widely used in the precision machining of various parts.However,these abrasives cannot satisfy the machining requirements of difficult-to-machine materials with high hardness,high strength,and strong wearing resistance.Although superhard abrasives can machine the above-mentioned materials,their dressing and manufacturing costs are high.By contrast,ceramic corundum abrasives fabricated by sol–gel method is a costeffective product between conventional and superhard abrasives.Ceramic corundum abrasives exhibit self-sharpening and high toughness.In this review,the optimization methods of ceramic corundum abrasive properties are introduced from three aspects:precursor synthesis,particle shaping,and sintering.Firstly,the functional mechanism of seeds and additives on the microstructural and mechanical properties of abrasives is analyzed.Specifically,seeds can reduce the phase transition temperature and improve fracture toughness.The grain size and uniformly dense structure can be controlled by applying an appropriate amount of multicomponent additives.Then,the urgent need of engineering application and machinability of special shape ceramic corundum abrasives is reviewed,and three methods of abrasive shaping are summarized.The micromold replication technique is highly advanced and can be used to prepare functional abrasives.Additionally,the influence of a new sintering method,namely,two-step sintering technique,on the microstructural and mechanical performance of ceramic corundum abrasives is summarized.Finally,the challenge and developmental trend of the optimization of ceramic corundum abrasives are prospected.Baoteng HUANG Changhe LI Yanbin ZHANG Wenfeng DING Min YANG Yuying YANG Han ZHAI Xuefeng XU Dazhong WANG Sujan DEBNATH Muhammad JAMIL Hao Nan Li Hafiz Muhammad ALI Munish Kumar GUPTA Zafar SAID 2021Chinese Journal of Aeronautics2021,34,6:11
4Effect of chromium on growth attributes in sunflower(Helianthus annuus L.)显示文摘Heavy metal soil pollution takes place when the metal concentration of soil exceeds natural background level and causes ecological destruction and deterioration of the environment.In the present study,a pot experiment was conducted to evaluate the effect of chromium-contaminated soil in sunflower(Helianthus annuus L.)growth attributes.Three different levels of chromium(Cr)i.e.,20, 40,and 60 mg/kg were applied to three varieties of sunflower(G-3,G-9,and G-59).The results of morphological,chemical,and yield parameters were recorded at crop maturity.The result showed that germination,root,and shoot lengths were decreased with increase in Cr concentrations.A gradual decrease was observed for various morphological parameters like root fresh and dry weights,shoot fresh and dry weights,and plant height with increase in Cr levels.A comparison among Cr treatments obtained a significant decrease in yield parameters as achenes/capitulum,achenes/plant,and 100 achenes weight in three varieties.Cr was significantly absorbed by roots but its transport to other parts of plants was slow,and uptake in seeds was much lower than in roots and shoots.FOZIA Andaleeb MUHAMMAD Anjum Zia MUHAMMAD Ashraf ZAFAR Mahmood Khalid 2008Journal of Environmental Sciences2008,20,12:9
5Cryogenic minimum quantity lubrication machining: from mechanism to application显示文摘Cutting fluid plays a cooling-lubrication role in the cutting of metal materials.However,the substantial usage of cutting fluid in traditional flood machining seriously pollutes the environment and threatens the health of workers.Environmental machining technologies,such as dry cutting,minimum quantity lubrication(MQL),and cryogenic cooling technology,have been used as substitute for flood machining.However,the insufficient cooling capacity of MQL with normal-temperature compressed gas and the lack of lubricating performance of cryogenic cooling technology limit their industrial application.The technical bottleneck of mechanical-thermal damage of difficult-to-cut materials in aerospace and other fields can be solved by combining cryogenic medium and MQL.The latest progress of cryogenic minimum quantity lubrication(CMQL)technology is reviewed in this paper,and the key scientific issues in the research achievements of CMQL are clarified.First,the application forms and process characteristics of CMQL devices in turning,milling,and grinding are systematically summarized from traditional settings to innovative design.Second,the cooling-lubrication mechanism of CMQL and its influence mechanism on material hardness,cutting force,tool wear,and workpiece surface quality in cutting are extensively revealed.The effects of CMQL are systematically analyzed based on its mechanism and application form.Results show that the application effect of CMQL is better than that of cryogenic technology or MQL alone.Finally,the prospect,which provides basis and support for engineering application and development of CMQL technology,is introduced considering the limitations of CMQL.Mingzheng LIU Changhe LI Yanbin ZHANG Qinglong AN Min YANG Teng GAO Cong MAO Bo LIU Huajun CAO Xuefeng XU Zafar SAID Sujan DEBNATH Muhammad JAMIL Hafz Muhammad ALI Shubham SHARMA 2021Frontiers of Mechanical Engineering2021,16,4:8
6Milling Force Model for Aviation Aluminum Alloy: Academic Insight and Perspective Analysis显示文摘Aluminum alloy is the main structural material of aircraft,launch vehicle,spaceship,and space station and is processed by milling.However,tool wear and vibration are the bottlenecks in the milling process of aviation aluminum alloy.The machining accuracy and surface quality of aluminum alloy milling depend on the cutting parameters,material mechanical properties,machine tools,and other parameters.In particular,milling force is the crucial factor to determine material removal and workpiece surface integrity.However,establishing the prediction model of milling force is important and difficult because milling force is the result of multiparameter coupling of process system.The research progress of cutting force model is reviewed from three modeling methods:empirical model,finite element simulation,and instantaneous milling force model.The problems of cutting force modeling are also determined.In view of these problems,the future work direction is proposed in the following four aspects:(1)high-speed milling is adopted for the thin-walled structure of large aviation with large cutting depth,which easily produces high residual stress.The residual stress should be analyzed under this particular condition.(2)Multiple factors(e.g.,eccentric swing milling parameters,lubrication conditions,tools,tool and workpiece deformation,and size effect)should be considered comprehensively when modeling instantaneous milling forces,especially for micro milling and complex surface machining.(3)The database of milling force model,including the corresponding workpiece materials,working condition,cutting tools(geometric figures and coatings),and other parameters,should be established.(4)The effect of chatter on the prediction accuracy of milling force cannot be ignored in thin-walled workpiece milling.(5)The cutting force of aviation aluminum alloy milling under the condition of minimum quantity lubrication(mql)and nanofluid mql should be predicted.Zhenjing Duan Changhe Li Wenfeng Ding Yanbin Zhang Min Yang Teng Gao Huajun Cao Xuefeng Xu Dazhong Wang Cong Mao Hao Nan Li Gupta Munish Kumar Zafar Said Sujan Debnath Muhammad Jamil Hafiz Muhammad Ali 2021Chinese Journal of Mechanical Engineering2021,34,1:7
7Nano-enhanced biolubricant in sustainable manufacturing:From processability to mechanisms显示文摘To eliminate the negative effect of traditional metal-working fluids and achieve sustainable manufacturing,the usage of nano-enhanced biolubricant(NEBL)is widely researched in minimum quantify lubrication(MQL)machining.It's improved tool wear and surface integrity have been preliminarily verified by experimental studies.The previous review papers also concluded the major influencing factors of processability including nano-enhancer and lubricant types,NEBL concentration,micro droplet size,and so on.Nevertheless,the complex action of NEBL,from preparation,atomization,infiltration to heat transfer and anti-friction,is indistinct which limits preparation of process specifications and popularity in factories.Especially in the complex machining process,in-depth understanding is difficult and meaningful.To fll this gap,this paper concentrates on the comprehensive quantitative assessment of processability based on tribological,thermal,and machined surface quality aspects for NEBL application in turning,milling,and grinding.Then it attempts to answer mechanisms systematically considering multi-factor influence of molecular structure,physicochemical properties,concentration,and dispersion.Firstly,this paper reveals advanced lubrication and heat transfer mechanisms of NEBL by quantitative comparison with biolubricant-based MQL machining.Secondly,the distinctive filmformation,atomization,and infiltration mechanisms of NEBL,as distinguished from metal-working fluid,are clarified combining with its unique molecular structure and physical properties.Furtherly,the process optimization strategy is concluded based on the synergistic relationship analysis among process variables,physicochemical properties,machining mechanisms,and performance of NEBL.Finally,the future development directions are put forward aiming at current performance limitations of NEBL,which requires improvement on preparation and jet methods respects.This paper will help scientists deeply understand effective mechanism,formulate process specifications,and find future development trend of this technology.Yanbin ZHANG Hao Nan LI Changhe LI Chuanzhen HUANG Hafiz Muhammad ALI Xuefeng XU Cong MAO Wenfeng DING Xin CUI Min YANG Tianbiao YU Muhammad JAMIL Munish Kumar GUPTA Dongzhou JIA Zafar SAID 2022Friction2022,10,6:5
8Algal biomass as a global source of transport fuels:Overview and development perspectives显示文摘As a result of the global fuel crisis of the early 1970 s,coupled with concerns for the environment,the use of biofuel has been on the increase in many regions throughout the world.At present,a total of approximately 30 billion(30×109) liters of biofuel are utilized worldwide annually,although most countries rely hugely on the first generation biofuel.The limitations of the first and second generation biofuel gave rise to current interest in algae as a promising alternative to these conventional biofuel sources.Algal biomass could provide a lion's share of the global transport fuel requirements in future.The present review highlights some important developments in,and potentials of algaculture as a major biomass resource of the future.However,the major constraint to commercial-scale algae farming for energy production is the cost factor,which must be addressed adequately before its potentials can be harnessed.Kifayat Ullah Mushtaq Ahmad Sofia Vinod Kumar Sharma Pengmei Lu Adam Harvey Muhammad Zafar Shazia Sultana C.N.Anyanwu 2014Progress in Natural Science:Materials International2014,24,4:5
9Electrostatic atomization minimum quantity lubrication machining:from mechanism to application显示文摘Metal cutting fluids(MCFs)under flood conditions do not meet the urgent needs of reducing carbon emission.Biolubricant-based minimum quantity lubrication(MQL)is an effective alternative to flood lubrication.However,pneumatic atomization MQL has poor atomization properties,which is detrimental to occupational health.Therefore,electrostatic atomization MQL requires preliminary exploratory studies.However,systematic reviews are lacking in terms of capturing the current research status and development direction of this technology.This study aims to provide a comprehensive review and critical assessment of the existing understanding of electrostatic atomization MQL.This research can be used by scientists to gain insights into the action mechanism,theoretical basis,machining performance,and development direction of this technology.First,the critical equipment,eco-friendly atomization media(biolubricants),and empowering mechanisms of electrostatic atomization MQL are presented.Second,the advanced lubrication and heat transfer mechanisms of biolubricants are revealed by quantitatively comparing MQL with MCF-based wet machining.Third,the distinctive wetting and infiltration mechanisms of electrostatic atomization MQL,combined with its unique empowering mechanism and atomization method,are compared with those of pneumatic atomization MQL.Previous experiments have shown that electrostatic atomization MQL can reduce tool wear by 42.4%in metal cutting and improve the machined surface Ra by 47%compared with pneumatic atomization MQL.Finally,future development directions,including the improvement of the coordination parameters and equipment integration aspects,are proposed.Wenhao Xu Changhe Li Yanbin Zhang Hafiz Muhammad Ali Shubham Sharma Runze Li Min Yang Teng Gao Mingzheng Liu Xiaoming Wang Zafar Said Xin Liu Zongming Zhou 2022International Journal of Extreme Manufacturing2022,4,4:4
10Overexpression of the phytochrome B gene from Arabidopsis thaliana increases plant growth and yield of cotton (Gossypium hirsutum)显示文摘The phytochrome B (PHYB) gene of Arabidopsis thaliana was introduced into cotton through Agrobacterium tumefaciens.Integration and expression of PHYB gene in cotton plants were confirmed by molecular evidence.Messenger RNA (mRNA) expression in one of the transgenic lines,QCC11,was much higher than those of control and other transgenic lines.Transgenic cotton plants showed more than a two-fold increase in photosynthetic rate and more than a four-fold increase in transpiration rate and stomatal conductance.The increase in photosynthetic rate led to a 46% increase in relative growth rate and an 18% increase in net assimilation rate.Data recorded up to two generations,both in the greenhouse and in the field,revealed that overexpression of Arabidopsis thaliana PHYB gene in transgenic cotton plants resulted in an increase in the production of cotton by improving the cotton plant growth,with 35% more yield.Moreover,the presence of the Arabidopsis thaliana PHYB gene caused pleiotropic effects like semi-dwarfism,decrease in apical dominance,and increase in boll size.Abdul Qayyum RAO Muhammad IRFAN Zafar SALEEM Idrees Ahmad NASIR Sheikh RIAZUDDIN Tayyab HUSNAIN 2011Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)2011,12,4:4
11Splenic injuries secondary to colonoscopy:Rare but serious complication显示文摘BACKGROUND Colonoscopy is a safe and routine diagnostic and therapeutic procedure for evaluation of large bowel diseases.Most common procedure related complications include bleeding and perforation but rarely a splenic Injury.AIM To investigate the reason for colonoscopy,presentation of patient with spleen injury,types of injury,diagnosis,management and outcomes of patients METHODS A structured search on four databases was done and 45 articles with 68 patients were selected.The reason for colonoscopy,presentation of patient with spleen injury,types of injury,diagnosis,management and outcomes of patients were identified and analyzed using SPSS.RESULTS The mean age of the patients was 62.7 years with 64%females.Twenty two percent had a complete splenic rupture with colonoscopy while 63%had subcapsular hematoma,spleen laceration and spleen avulsion.The most common reason for colonoscopy was screening(46%)followed by diagnostic colonoscopy(28%).Eighty seven percent of patients presented with abdominal pain.Patients with spleen rupture mostly required splenectomy(47%),while minor spleen hematomas and lacerations were managed conservatively(38%).Six percent of the patients were managed with proximal splenic artery splenic embolization and 4%were managed with laparoscopic repair.The overall mortality was 10%while 77%had complete recovery.The reason of colonoscopy against presentation specifically,abdominal pain showed no statistical significance P=0.69.The indication of colonoscopy had no significant impact on incidence of splenic injury(P=0.89).Majority of the patients(47%)were managed with splenectomy while the rest were managed conservatively(P=0.04).This association was moderately strong at a cramer’s V test(0.34).The Fisher exact test showed a higher mortality with spleen rupture(P=0.028).CONCLUSION Spleen rupture due to colonoscopy is a significant concern and is associated with high mortality.The management of the patients can be individualized based on clinical presentation.Waqas Ullah Mamoon Ur Rashid Asif Mehmood Yousaf Zafar Ishtiaq Hussain Deepika Sarvepalli Muhammad Khalid Hasan 2020World Journal of Gastrointestinal Surgery2020,12,2:4
12A reliable, delay bounded and less complex communication protocol for multicluster FANETs显示文摘Wajiya Zafar Bilal Muhammad Khan 2017Digital Communications and Networks2017,3,1:4
13Mechanisms and molecular approaches for heat tolerance in rice (Oryza sativa L.) under climate change scenario显示文摘Rice, a staple cereal crop in many parts of the world, has been confronted with multiple environmental stresses including high temperature, negatively impacts the booting as well as anthesis growth stages. The situation is further complicated by the changing climatic conditions, resulting in gradual escalation of temperature as well as changing the rainfall pattern and frequency, thus raising a concern of food security worldwide. The situation can be combat by developing rice varieties with excellent genetics with improved morpho-physiological, biochemical, and molecular mechanisms, together can minimize the adverse effects of heat stress. Here, several strategies(encompassing genetic and genomic, and mechanisms involved) for mitigating the impact of high temperature on rice have been discussed. Finally, the utilization of genomic knowledge in augmenting the conventional breeding approaches have been comprehensively elaborated to develop heat tolerant germplasm.Syed Adeel Zafar Amjad Hameed Muhammad Amjad Nawaz MA Wei Mehmood All Noor Muzammil Hussain Mehboob-ur-Rahman 2018Journal of Integrative Agriculture2018,17,4:4
14Sustained virological response based on rapid virological response in genotype-3 chronic hepatitis C treated with standard interferon in the Pakistani population显示文摘AIM:To document the sustained virological response (SVR) in rapid virological responders (RVR) of genotype-3 chronic hepatitis C with standard interferon (SdIF). METHODS:Hepatitis C genotype-3 patients during the period July 2006 and June 2007 were included. Complete blood counts, prothrombin time, ALT, albumin, qualitative HCV RNA were done. SdIF and ribavirin were given for 4 wk and qualitative HCV RNA was repeated. Those testing negative were allocated to group-A while the rest were allocated to group-B. Treatment was continued a total of 16 and 24 wk for group A and B respectively. HCV RNA was repeated after 24 wk of treatment. End virological and sustained virological responses were compared by χ2 test. ROC of pretreatment age, ALT and albumin were plotted for failure to achieve SVR. RESULTS:Of 74 patients treated, RCV RNA after 16 wk of therapy became undetectable in 34 (45.9%) and was detectable in 40 (54.1%) and were allocated to groups A and B respectively. SVR was achieved in 58.8% and 27.8% in groups A and B respectively. SVR rates were significantly higher in patients who had RVR as compared to those who did not (P = 0.0;γ = 2). Both groups combined ETR and SVR were 70% and 33% respectively. ROC plots of pretreatment age, ALT and albumin for SVR showed only ALT to have a significantly large area under the curve.CONCLUSION:SVR rates were higher in patients who had RVR with SdIF and high pre treatment ALT values correlated to probability of having RVR.Bader Faiyaz Zuberi Faisal Faiyaz Zuberi Sajjad Ali Memon Muhammad Hafeez Qureshi Sheikh Zafar Ali Salahuddin Afsar 2008World Journal of Gastroenterology2008,14,14:3
15Colon mucosal neoplasia referred for endoscopic mucosal resection:Recurrence of adenomas and prediction of submucosal invasion显示文摘BACKGROUND Endoscopic mucosal resection(EMR)is an effective and minimally invasive alternative to surgery for large polyps and laterally spreading lesions.Gross morphology and surface characteristics may help predict submucosal invasion of the lesion(SMIL)during endoscopic evaluation.This is one of the largest singlecenter studies reporting endoscopic mucosal resection for larger(≥20 mm)colorectal lesions in the United States.AIM To determine the recurrence rate of adenomas and endoscopic features that may predict submucosal invasion of colonic mucosal neoplasia.METHODS This is a retrospective cohort study of all the patients referred for endoscopic mucosal resection for lesions≥20 mm,spanning a period from January 2013 to February 2017.The main outcome measure was identifying features that may predict submucosal invasion of mucosal lesions and predict recurrence of adenomas on follow-up surveillance colonoscopy performed at 4-6 mo.RESULTS A total of 480 patients with 500 lesions were included in the study.The median age was 68(Inter quantile range:14)with 52%males.The most common lesion location was ascending colon(161;32%).Paris classification 0-IIa(Flat elevation of mucosa-316;63.2%);Kudo Pit Pattern IIIs(192;38%)and Granular surface morphology(260;52%)were most prevalent.Submucosal invasion was present in 23(4.6%)out of 500 lesions.The independent risk factors for SMIL were Kudo Pit Pattern IIIL+IV and V(Odds ratio:4.5;P value<0.004)and Paris classification 0-IIc(Odds ratio:18.2;P value<0.01).Out of 500,354 post-endoscopic mucosal resection scars were examined at surveillance colonoscopy.Recurrence was noted in 21.8%(77 cases).CONCLUSION There was overall low prevalence of SMIL in our study.Kudo pit pattern(IIIL+IV and V)and Paris classification 0-IIc were the only factors identified as an independent risk factor for submucosal invasion.The independent risk factor for recurrence was adenoma size(>40 mm).Almost all recurrences(98.8%)were treated endoscopically.Mamoon Ur Rashid Neelam Khetpal Hammad Zafar Saeed Ali Evgeny Idrisov Yuan Du Assaf Stein Deepanshu Jain Muhammad Khalid Hasan 2020World Journal of Gastrointestinal Endoscopy2020,12,7:3
16Fighting against fall armyworm by using multiple genes pyramiding and silencing(MGPS) technology显示文摘The pest Fall Armyworm(FAW),Spodoptera frugiperda belonging to the order Lepidoptera,is one of the most devastating insect pests resulting in severe economic losses to maize,rice,wheat,cotton and soybean in South America,Africa and Asia.It consists of two morphologically indistinguishable strains:the“corn strain”feeding mainly on maize,cotton and sorghum;the“rice strain”mostly feeding on rice and various grasses(Gouin et al.,2017).Adults of FAW have strong migration ability to fly 100 km per night.In 2018 it was detected in India and then spreads to Bangladesh,Thailand,Myanmar,and China in 2019(http://gffzz7e8ce5e2b4d84f4ehppuxbxf9ucuw6k9f.ffgz.tsg.suse.edu.cn/fall-armyworm/en/).It is a polyphagous lepidopteran herbivore,attacks more than 350 plant species,and causes destructive damage to many economically important crops.The FAW causes up to 30%-60% yield losses.Maozhi Ren Muhammad Mubashar Zafar Huijuan Mo Zhaoen Yang Fuguang Li 2019Science China(Life Sciences)2019,62,12:3
17Machinability of ultrasonic vibration-assisted micro-grinding in biological bone using nanolubricant显示文摘Bone grinding is an essential and vital procedure in most surgical operations.Currently,the insufficient cooling capacity of dry grinding,poor visibility of drip irrigation surgery area,and large grinding force leading to high grinding temperature are the technical bottlenecks of micro-grinding.A new micro-grinding process called ultrasonic vibration-assisted nanoparticle jet mist cooling(U-NJMC)is innovatively proposed to solve the technical problem.It combines the advantages of ultrasonic vibration(UV)and nanoparticle jet mist cooling(NJMC).Notwithstanding,the combined effect of multi parameter collaborative of U-NJMC on cooling has not been investigated.The grinding force,friction coefficient,specific grinding energy,and grinding temperature under dry,drip irrigation,UV,minimum quantity lubrication(MQL),NJMC,and U-NJMC micro-grinding were compared and analyzed.Results showed that the minimum normal grinding force and tangential grinding force of U-NJMC micro-grinding were 1.39 and 0.32 N,which were 75.1%and 82.9%less than those in dry grinding,respectively.The minimum friction coefficient and specific grinding energy were achieved using U-NJMC.Compared with dry,drip,UV,MQL,and NJMC grinding,the friction coefficient of U-NJMC was decreased by 31.3%,17.0%,19.0%,9.8%,and 12.5%,respectively,and the specific grinding energy was decreased by 83.0%,72.7%,77.8%,52.3%,and 64.7%,respectively.Compared with UV or NJMC alone,the grinding temperature of U-NJMC was decreased by 33.5%and 10.0%,respectively.These results showed that U-NJMC provides a novel approach for clinical surgical micro-grinding of biological bone.Yuying YANG Min YANG Changhe LI Runze LI Zafar SAID Hafiz Muhammad ALI Shubham SHARMA 2023Frontiers of Mechanical Engineering2023,18,1:3
18Synthesis, Crystal Structure and Antimicrobial Activity of Ethyl 2-(1-cyclohexyl-4-phenyl-1H-1,2,3-triazol-5-yl)-2-oxoacetate显示文摘A novel 1,4,5-trisubstituted 1,2,3-triazole(C18H21N3O3) was synthesized by a one-pot three component reaction of 1-azidocyclohexane, 1-copper(I) phenylethyne and ethoxalyl chloride at room temperature. The molecular structure was determined by single-crystal X-ray analysis. The compound crystallizes in the monoclinic system, space group P21/n with a = 12.8167(9), b = 8.0966(6), c = 16.7079(9) , β = 98.716(2)o, Z = 4 and V = 1713.8(2). In the crystal, the molecules are related by inversion and paired into dimers via C–H···O and C–O···C interactions involving(oxo) acetate groups. Furthermore, X-ray analysis results are compared with the optimized structure computed by using B3 LYP method with 6-311 G basis set. The calculated results showed that optimized geometry can well reproduce the crystal structure parameters. The bioassay results indicate that the compound has good antibacterial and antifungal activities.MUHAMMAD Naeem Ahmed SHAHID Hameed KHAWAJA Ansar Yasin IFZAN Arshad IHSAN-ul-Haq SAFEENA Zafar MUHAMMAD Nawaz Tahir 2014Chinese Journal of Structural Chemistry2014,33,11:3
19Minimum quantity lubrication machining of aeronautical materials using carbon group nanolubricant: From mechanisms to application显示文摘It is an inevitable trend of sustainable manufacturing to replace flood and dry machining with minimum quantity lubrication(MQL)technology.Nevertheless,for aeronautical difficult-tomachine materials,MQL couldn’t meet the high demand of cooling and lubrication due to high heat generation during machining.Nano-biolubricants,especially non-toxic carbon group nano-enhancers(CGNs)are used,can solve this technical bottleneck.However,the machining mechanisms under lubrication of CGNs are unclear at complex interface between tool and workpiece,which characterized by high temperature,pressure,and speed,limited its application in factories and necessitates in-depth understanding.To fill this gap,this study concentrates on the comprehensive quantitative assessment of tribological characteristics based on force,tool wear,chip,and surface integrity in titanium alloy and nickel alloy machining and attempts to answer mechanisms systematically.First,to establish evaluation standard,the cutting mechanisms and performance improvement behavior covering antifriction,antiwear,tool failure,material removal,and surface formation of MQL were revealed.Second,the unique film formation and lubrication behaviors of CGNs in MQL turning,milling,and grinding are concluded.The influence law of molecular structure and micromorphology of CGNs was also answered and optimized options were recommended by considering diverse boundary conditions.Finally,in view of CGNs limitations in MQL,the future development direction is proposed,which needs to be improved in thermal stability of lubricant,activity of CGNs,controllable atomization and transportation methods,and intelligent formation of processing technology solutions.Xin CUI Changhe LI Wenfeng Ding Yun CHEN Cong MAO Xuefeng XU Bo LIU Dazhong WANG Hao Nan LI Yanbin ZHANG Zafar SAID Sujan DEBNATH Muhammad JAMIL Hafiz Muhammad ALI Shubham SHARMA 2022Chinese Journal of Aeronautics2022,35,11:3
20Theoretical investigation of sulfur defects on structural, electronic,and elastic properties of ZnSe semiconductor显示文摘The structural, electronic, and elastic properties of Zn Se1-xSx for the zinc blende structures have been studied by using the density functional theory. The calculations were performed using the plane wave pseudopotential method, as implemented in Quantum ESPRESSO. The exchange-correlation potential is treated with the local density approximation pz-LDA for these properties. Moreover, LDA+U approximation is employed to treat the 'd' orbital electrons properly. A comparative study of the band gap calculated within both LDA and LDA+U schemes is presented. The analysis of results show considerable improvement in the calculation of band gap. The inclusion of compositional disorder increases the values of all elastic constants. In this study, it is found that elastic constants C11, C12, and C44 are mainly influenced by the compositional disorder. The obtained results are in good agreement with literature.Muhammad Zafar Shabbir Ahmed M.Shakil M.A.Choudhary K.Mahmood 2015Chinese Physics B2015,24,7:2
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