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A remotely sensed tracking of forest cover and associatedtemperature change in Margalla hills

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International Journal of Digital Earth 2019年第10期12卷 1133-1150页

作者： Noora Khalid Saleem Ullah sheikh Saeed Ahmad Asad Ali Farrukh Chishtie Department of Space Science Institute of Space TechnologyIslamabadPakistan Department of Environmental Sciences Fatima Jinnah Women UniversityRawalpindiPakistan

Worldwide, forest degradation is a serious environmental issue, and inPakistan, forest wealth is depleting at the highest rate in South Asia. Toensure sustainable development goals of environmental stewardship,social development and economic growth, a sound monitoring andregulatory mechanism is essential for tracking forest cover changes. Thisstudy aims to quantify the decline of forest reserves and associatedtemperature variations in a relatively unexplored biodiversity hotspot ofIslamabad, Margalla Hills National Park (MHNP). Imagery acquired byLandsat TM (Thematic Mapper) for the year 1992, 2000 and 2011 areused to assess the spatial and temporal changes occurred over the lasttwo decades (from 1992 to 2011). A robust hybrid-classification routineis implemented to monitor the changes in forest cover and ANOVAalong with Tukey’s HSD (Honestly Significant Difference) test is used totest the significance of temperature variation associated with a shift inland cover classes. The results showed a significant growth insettlements, agricultural area and barren soil whereas water body, lowervegetation, scrub and pine forest are diminishing. In both decades, thetemperature alteration associated with a change in land cover classesare statistically significant (confirmed by ANOVA and Tukey’s HSD tests)for most of the land use/land cover classes. Based on these findings, thisstudy concludes that forests are dwindling at MHNP and the degradingcondition of the forest is below par and necessitates the promotion ofconservation practices to minimize ecological disturbances.

关键词： Margalla hills Landsat thematic mapper(Landsat TM) forest cover change hybrid classification land cover classes ANOVA Tukey’s HSD

A kinetic approach to evaluate salinity effects on carbon mineralization in a plant residue-amended soil

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2006年第10期7卷 788-793页

作者： NOURBAKHSH Farshid sheikh-HOSSEINI Ahmad R. Department of Soil Science School of Agriculture Isfahan University of Technology Isfahan 84154 Iran

The interaction of salinity stress and plant residue quality on C mineralization kinetics in soil is not well understood. A laboratory experiment was conducted to study the effects of salinity stress on C mineralization kinetics in a soil amended with alfalfa, wheat and corn residues. A factorial combination of two salinity levels （0.97 and 18.2 dS/m） and four levels of plant residues （control, alfalfa, wheat and corn） with three replications was performed. A first order kinetic model was used to describe the C mineralization and to calculate the potentially mineralizable C. The CO2-C evolved under non-saline condition, ranged from 814.6 to 4842.4 mg CO2-C/kg in control and alfalfa residue-amended soils, respectively. Salinization reduced the rates of CO2 evolution by 18.7%, 6.2% and 5.2% in alfalfa, wheat and corn residue-amended soils, respectively. Potentially mineralizable C （Co） was reduced significantly in salinized alfalfa residue-treated soils whereas, no significant difference was observed for control treatments as well as wheat and corn residue-treated soils. We concluded that the response pattern of C mineralization to salinity stress depended on the plant residue quality and duration of incubation.

关键词： Salinity stress Carbon mineralization First-order kinetics Plant residues Residue quality

Dynamic flexural strength of Aluminosilicate glass with a perspective of impulsive and quasi-impulsive responses: An experimental-numerical coupled evaluation

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Chinese Journal of Aeronautics 2024年第12期37卷 388-403页

作者： Muhammad Aamir RAZA Tao SUO Uzair Ahmed DAR Muhammad ATIF Muhammad Zakir sheikh School of Aeronautics and Institute of Extreme Mechanics Northwestern Polytechnical UniversityXi’an 710072China Joint International Research Center of Impact Dynamics and Its Engineering Application Northwestern Polytechnical UniversityXi’an 710072China Shaanxi Key Laboratory of Impact Dynamics and Engineering Application Northwestern Polytechnical UniversityXi’an 710072China National Key Laboratory of Strength and Structural Integrity Northwestern Polytechnical UniversityXi’an 710072China

The flexural strength of glass is a critical design parameter for applications encountering impact ***,the micro defects,specimen geometry,loading rate,and load transformation from a quasi-dynamic to quasi-impulsive state may influence the measurement *** to the stochastic and amorphous nature of the material,an accurate determination of the flexural strength remains a *** this two-fold study,a coupled experimental-numerical strategy was devised to evaluate the dynamic flexural *** the first phase,three-point bending experiments were conducted on a novel“Electromagnetic Split Hopkinson Pressure Bar(ESHPB)”.The incident stress signal and fracture time were recorded from experimental data,while the flexural strength was indirectly computed from a numerical algorithm.A quantitative comparison of the flexural strength with those in existing literature established the accuracy of the proposed *** of the study indicate that the specimen response became independent of the support conditions under impulsive *** being said,the specimen behaved like it had an infinite span length,and the measured flexural strength remained the same whether the specimen was supported or ***,the specimen also maintained contact at the interfaces of the incident bar and fixture supports for the entire loading *** the second part of this study,the computed flexural strength was used to calibrate the existing JH-2 *** prediction of the damage propagation corroborated with that obtained from reprography images,though *** work presents a precise and robust methodology to determine the dynamic flexural strength of brittle ceramics like Aluminosilicate glass over traditional experimental procedures to facilitate its adoption.

关键词： Dynamic flexural strength Damage mechanism Flexural fracture Numerical simulation Aluminosilicate glass

Molecular typing of methicillin and vancomycin-resistant Staphylococcus aureus isolated from clinical specimens by double locus sequence typing(DLST)method

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BIOCELL 2020年第3期44卷 411-419页

作者： SOHEILA HASANIAN NOUR AMIRMOZAFARI AHMAD FARAJZADEH sheikh IRAJ MEHREGAN Department of Biology Science and Research BranchIslamic Azad UniversityTehranIran Department of Microbiology School of MedicineIran University of Medical SciencesTehranIran Department of Microbiology School of MedicineAhvaz Jundishapur University of Medical SciencesAhvazIran

Methicillin-resistant Staphylococcus aureus(MRSA)strains are the essential cause of infections in communities and *** present study was conducted to determine the molecular typing of MRSA,isolated from hospitalized patients,using the double-locus sequence typing(DLST).In total,280 *** isolated from clinical specimens by phenotypic(catalase,coagulase,DNase,oxacillin,vancomycin screening agar and antibiotic disk diffusion),and molecular methods(PCR for determining the mecA,vanA and nuc genes).The DLST and sequencing was performed for MRSA containing *** of 280 specimens,confirmed as Staphylococcus aureus(***),123(43.9%)strains were *** highest resistance toward the erythromycin(15μg),followed by ciprofloxacin(5μg),clindamycin(2μg),tetracycline(30μg),gentamicin(10μg)and rifampicin(5μg),was 98.3%,97.5%,94.3%,90.2%,83.7%and 41.4%,***,the least resistance(0%)was observed in each of teicoplanin(30μg),linzolide(30μg),and vancomycin(30μg).All(100%)of MRSA strains had the mecA,and none of them have had the *** results of DLST showed that the most common sequence types were BPH 2003 and *** DLST type 18-32 was a significant cluster of *** sequencing MRSA and comparing the dominant types via the DLST,it is possible to establish the etiology of the disease in a much shorter time,and prevent the complications of the ***,the combination of partial sequences of clfB and spa can serve as useful genetic markers for MRSA *** concluded that the MRSA in our region was relatively high,but no vancomycin resistance was *** majority of the MRSA DLST type was 18–32.

关键词： Antibiotic resistance DLST MRSA Staphylococcus aureus

Study on the Preparation and Properties of Nannochloropsis Calcium-chelating Peptide

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Study on the Preparation and Properties of Nannochloropsis C...

作者： Arooj Rehman sheikh 江苏大学

学位级别：硕士

本论文分析了微拟绿球藻Nannochloropsis oceanica的主要成分,Nannancholoropsis oceanica蛋白来源丰富,易于获得且价格低廉。微拟球藻是良好蛋白质来源。有很多方法可以从样品中提取蛋白质,其中超声辅助提取研究应用广泛。适度超声辅... 详细信息

本论文分析了微拟绿球藻Nannochloropsis oceanica的主要成分,Nannancholoropsis oceanica蛋白来源丰富,易于获得且价格低廉。微拟球藻是良好蛋白质来源。有很多方法可以从样品中提取蛋白质,其中超声辅助提取研究应用广泛。适度超声辅助提取可提高提取效率,并提高产品质量,同时减少溶剂消耗和时间。天然制备的钙结合肽可有效替代合成药品。Nanocholoropsis蛋白是制备钙螯合肽的较好原料。钙离子可以与肽/氨基酸之间的相互作用形成螯合。首先通过单因素试验以螯合活性、螯合率和收率为指标对超声波功率、质量比、超声波时间、超声波温度和氢氧化钠浓度等条件进行了螯合条件优化。钙螯合肽初步鉴定采用茚三酮显色法。采用不同的酸碱度、高温加热、体外模拟胃肠道消化和PBS缓冲液对钙离子螯合肽的稳定性进行了研究。然后通过紫外光谱、荧光光谱、FTIR、Zeta电位、TG-DCS和X射线分别对螯合物进行表征。最后用SEM和AFM对多肽和钙结合多肽进行了形态分析,并对钙螯合肽进行氨基酸和分子量分布分析,主要研究结论如下:（1）首先优化获得微拟球藻蛋白的最佳提取工艺条件;提取温度40℃,时间60分钟,超声波功率800W,料液比1:50 g/m L,Na OH浓度0.4M,此条件下蛋白提取率94.81±0.151%,粗蛋白得率51.69±0.0121%,提取物中蛋白纯度76.86±0.0191%。然而,传统碱提3h微藻蛋白提取率只有60.02±0.01%。超声提取蛋白提取率高34.79%,提取时间节约三分之二。（2）研究了蛋白的不同理化性质,如起泡能力,起泡稳定性随p H值的升高呈增加趋势,吸水能力随p H值的升高变化。蛋白质的吸油能力在p H值为11时为96.8%,而等电点为p H3.5。当p H大于6时,微绿球藻蛋白溶解度大于97.94±0.015%。蛋白的理化性质表明,p H值的变化对其性质产生显著影响。等电点的溶解度、OAC、WAC、FC和FS最小。微藻的功能特性主要与它们的理化特性有关。因此,利用适宜条件提取微拟球藻蛋白可以用于食品工业,并有可能取代许多合成产品（3）形成钙螯合物的最佳条件:料液比9:1,螯合时间15min,螯合p H 9,温度40℃,功率1000W,此条件下钙螯合率为61.89±0.121%,钙螯合活性为9.08±0.151%,钙螯合物得率为65.57±0.190%。（4）通过Ca螯合物在不同浓度的PBS缓冲液、加热温度、p H水平和体外模拟消化稳定性分析表明,螯合物稳定性较好。经胃液模拟消化30分钟,Ca肽的保留率为81.93±0.00761%,胰蛋白酶消化进一步降低了钙离子保留率。钙螯合肽在p H高于6时均较稳定。Ca螯合肽的稳定性受温度影响较小,在磷酸盐缓冲液浓度较低（10mmol/L）时,螯合物稳定。（5）FTIR光谱显示了螯合物的存在,紫外光谱扫描、荧光光谱、ζ电位、粒度分布和氨基酸分析不仅证实了螯合物的产生,并且不同的光谱分析和检测信号还表明金属离子与微藻肽中的氨基、羧基和其他活性螯合基团形成金属螯合物。（6）SEM和AFM图像显示了螯合肽的致密结构。分析结果表明,微藻多肽-金属离子螯合物应该是通过螯合产生的新物质。

关键词：超声波微拟球藻钙螯合肽稳定性表征

Synthesis of titanium oxycarbonitride by carbothermal reduction and nitridation of ilmenite with recycling of polyethylene terephthalate (PET)

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International Journal of Minerals,Metallurgy and Materials 2017年第4期24卷 444-454页

作者： Eltefat Ahmadi Ahmad Fauzi Hashim Hussin Norlia Baharun Kamar Shah Ariffin sheikh Abdul Rezan School of Materials & Mineral Resources Engineering Universiti Sains Malaysia Engineering Campus 14300 Nibong Tebal Penang Malaysia

An innovative and sustainable carbothermal reduction and nitridation(CTRN) process of ilmenite(FeTiO_3) using a mixture of polyethylene terephthalate(PET) and coal as the primary reductant under an H_2–N_2 atmosphere was proposed. The use of PET as an alternative source of carbon not only enhances the porosity of the pellets but also results in the separation of Fe from titanium oxycarbonitride(TiOxCyNz) particles because of the differences in surface tension. The experiments were carried out at 1250°C for 3 h using four different PET contents ranging from 25wt% to 100wt% in the reductant. X-ray diffraction(XRD),scanning electron microscopy(SEM) in conjunction with energy-dispersive X-ray spectroscopy(EDX),and LECO elemental analysis were used to study the phases and microstructures of the reduced samples. In the case of 75wt% PET,iron distinctly separated from the synthesized Ti OxCyNz phase. With increasing PET content in the sample,the reduction and nitridation rates substantially increased. The synthesis of an oxycarbonitride with stoichiometry of TiO_(0.02)C_(0.13)N_(0.85) with minimal intermediate titanium sub-oxides was achieved. The results also showed that the iron particles formed from CTRN of FeTiO_3 exhibited a spherical morphology,which is conducive for Fe removal via the Becher process.

关键词： carbothermal reduction nitridation polyethylene terephthalate titanium oxycarbonitride ilmenite

Traditional Indian Medicine and Traditional Chinese Medicine:A Comparative Overview

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Chinese Medicine and Culture 2019年第3期2卷 105-113页

作者： sheikh Faruque Elahee Huijuan Mao Xueyong Shen Departments of Meridians and Acupoints School of Acupuncture‑Moxibustion and TuinaShanghai University of Traditional Chinese Medicine Experimental Acupuncture-Moxibustion School of Acupuncture‑Moxibustion and TuinaShanghai University of Traditional Chinese Medicine Shanghai Research Center of Acupuncture and Meridian ShanghaiChina

Traditional Indian medicine or Ayurveda(阿育吠陀)and Traditional Chinese Medicine remain the most ancient yet living *** are the two great traditional medicines with rich philosophical,experiential,and experimental *** the systems have been developed and enriched by thousands of years of practices,observations,and *** India and China are neighbors,some exchange of medical ideas and practices might have occurred between the two nations since ancient ***,when the two traditional medicines are examined closely,many similarities become apparent in the theories and practices along with individual differences.

关键词： Acupuncture ashtanga ayurveda(阿斯汤加) ayurveda(阿育吠陀) traditional Chinese medicine traditional Indian medicine

2D MXene Ti_(3)C_(2)T_(x)Enhanced Plasmonic Absorption in Metasurface for Terahertz Shielding

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Computers, Materials & Continua 2023年第5期75卷 3453-3464页

作者： Zaka Ullah Muath Al Hasanl Ismail Ben Mabrouk Muhammad Junaid Fawad sheikh Faculty of Electrical Engineering College of EngineeringAl Ain UniversityAl Ain64141UAE Department of Electrical Engineering Durham UniversityDurhamUK Department of Electrical Engineering Baluchistan University of Technology and management sciencesQuettaPakistan Institute of Digital Signal Processing Universitat Duisburg EssenDuisburgGermany

With the advancement of technology,shielding for terahertz(THz)electronic and communication equipment is increasingly *** metamaterial absorption technique is mostly used to shield electromagnetic interference(EMI)in THz sensing *** most widely used THz metamaterial absorbers suffer from their narrowband properties and the involvement of complex fabrication *** with multifunctional properties,such as adjustable conductivity,broad bandwidth,high flexibility,and robustness,are driving future development to meet THz shielding *** this article,a theoretical simulation approach based on finite difference time domain(FDTD)is utilized to study the absorption and shielding characteristics of a two-dimensional(2D)MXene Ti_(3)C_(2)T_(x) metasurface absorber in the THz *** proposed metamaterial structure is made up of a square-shaped array of MXene that is 50 nmthick and is placed on top of a silicon *** bottom surface of the silicon is metalized with gold to reduce the transmission and ultimately enhance the absorption at 1–3 *** symmetric adjacent space between theMXene array results in a widening of *** proposed metasurface achieves 96%absorption under normal illumination of the incident source and acquires an average of 25 dB shielding at 1 THz bandwidth,with the peak shielding reaching 65 *** results show that 2D MXene-based stacked metasurfaces can be proven in the realization of low-cost devices for THz shielding and sensing applications.

关键词： EMI shielding terahertz plasmonic absorber metasurface

Comparison between intravenous morphine versus fentanyl in acute pain relief in drug abusers with acute limb traumatic injury

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World Journal of Emergency Medicine 2019年第1期10卷 27-32页

作者： Hojat sheikh Motahar Vahedi Hadi Hajebi Elnaz Vahidi Amir Nejati Morteza Saeedi Emergency Medicine Department Shariati Hospital Tehran University of Medical Sciences

BACKGROUND: Rapid and effective pain relief in acute traumatic limb injuries(ATLI) is one of the most important roles of emergency physicians. In these situations, opioid addiction is an important concern because of the dependency on opioids. The study aims to compare the effectiveness of intravenous(IV) fentanyl versus morphine in reducing pain in patients with opioid addiction who suffered from ***: In this double-blind randomized clinical trial, 320 patients with ATLI, who presented to the emergency department(ED) from February 2016 to April 2016, were randomly divided into two groups. One group(160 patients) received 0.1 mg/kg IV morphine. The other group(160 patients) received 1 mcg/kg IV fentanyl. Patients' demographic data, pain score at specif ic intervals, vital signs, side effects, satisfaction and the need for rescue analgesia were ***: Eight patients in the morphine group and five patients in the fentanyl group were excluded. Pain score in the fentanyl group had a significant decrease at 5-minute follow-up(P value=0.00). However, at 10, 30, and 60-minute follow-ups no signifi cant differences were observed between the two groups in terms of pain score reduction. The rescue analgesia was required in 12(7.7%) patients in the fentanyl group and in 48(31.6%) patients in the morphine group(P value=0.00). No signifi cant difference was observed regarding side effects, vital signs and patients' satisfaction between the two ***: Fentanyl might be an effective and safe drug in opioid addicts suffering from ATLI.

关键词： Fentanyl Morphine Opioid addiction Acute traumatic limb injury Pain score