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Response surface methodology-based optimization of ultrasound-assisted extraction of β-sitosterol and lupeol from Astragalus atropilosus(roots) and validation by HPTLC method

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Asian Pacific Journal of Tropical Biomedicine 2020年第6期10卷 281-292页

作者： Perwez Alam Nasir A.Siddiqui Ali S.Alqahtani Anzarul Haque Omer A.Basudan Saleh I.Alqasoumi m.u.khan Department of Pharmacognosy College of PharmacyKing Saud UniversityP.O.Box-2457Riyadh-11451Saudi Arabia Department of Pharmacognosy College of PharmacyPrince Sattam bin Abdulaziz UniversityAl-KharjKSA Department of Pharmaceutical Chemistry&Pharmacognosy Unaizah College of PharmacyQassim UniversityAl QassimSaudi Arabia

Objective:To optimize the ultrasonication method for efficient extraction ofβ-sitosterol and lupeol from the roots of Astragalus atropilosus using Box-Behnken design of response surface methodology(RSm),and its validation by high performance thin layer chromatography(HPTLC)***:ultrasonication method was used to extractβ-sitosterol and lupeol from Astragalus atropilosus(roots).RSm was used to optimize the different extraction parameters *** to solid ratio(10–14 m L/g),temperature(60-80℃)and time(40–60 min)to maximize the yield ofβ-sitosterol and *** quantitative estimation ofβ-sitosterol and lupeol was done in chloroform extract of Astragalus atropilosus by validated HPTLC method on 10 cm×20 cm glass-backed silica gel 60 F254 plate using hexane and ethyl acetate(8:2,v/v)as mobile ***:A quadratic polynomial model was found to be most appropriate with regard to R1(yield of total extraction;R2/%CV=0.9948/0.28),R2(β-sitosterol yield;R2/%CV=0.9923/0.39)and R3(lupeol yield;R2/%CV=0.9942/0.97).The values of adjusted R2/predicted R2/signal to noise ratio for R1,R2,and R3 were 0.9782/0.9551/48.77,0.9904/0.9110/31.33,and 0.9927/0.9401/36.08,respectively,indicating a high degree of correlation and adequate *** linear correlation plot between the predicted and experimental values for R1,R2,and R3 showed high values of R2 ranging from 0.9905-0.9973.β-sitosterol and lupeol in chloroform extract of Astragalus atropilosus were detected at Rf values of 0.22 and 0.34,respectively,atλmax=518 *** optimized ultrasonic extraction produced 8.462%w/w of R1,0.451%w/w of R2 and 0.172%w/w of R3 at 13.5 m L/g liquid to solid ratio,78℃of temperature and 60 min of ***:The experimental findings of RSm optimized extraction and HPTLC analysis can be further applied for the efficient extraction ofβ-sitosterol and lupeol in other species of Astragalus.

关键词： β-sitosterol Lupeol Box-Behnken design Astragalus High performance thin layer chromatography

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Correction of failure in antenna array using matrix pencil technique

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Chinese Physics B 2017年第6期26卷 491-498页

作者： S u khan m K A Rahim Advanced RF & microwave Research Group Department of Communication Engineering Faculty of Electrical Engineering Universiti Teknologi Malaysia 81310 Skudai Johor Malaysia

In this paper a non-iterative technique is developed for the correction of faulty antenna array based on matrix pencil technique（mPT）. The failure of a sensor in antenna array can damage the radiation power pattern in terms of sidelobes level and nulls. In the developed technique, the radiation pattern of the array is sampled to form discrete power pattern information set. Then this information set can be arranged in the form of Hankel matrix（Hm） and execute the singular value decomposition（SVD）. By removing nonprincipal values, we obtain an optimum lower rank estimation of Hm. This lower rank matrix corresponds to the corrected pattern. Then the proposed technique is employed to recover the weight excitation and position allocations from the estimated matrix. Numerical simulations confirm the efficiency of the proposed technique, which is compared with the available techniques in terms of sidelobes level and nulls.

关键词： array correction low rank estimation matrix pencil technique singular value decomposition

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On the detection of closed orbits in time-dependent systems by using double-pulse lasers

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Communications in Theoretical Physics 2020年第9期72卷 111-117页

作者： S u khan m L Du Institute of Theoretical Physics Chinese Academy of Sciences.Beijing 100190China university of Chinese Academy of Sciences Beijing100049China

In the photodetachment of atoms or negative ions by a double-pulse laser, the first pulse of the double-pulse laser generates waves and the delayed second pulse may detect them. The phenomenon of the excitation and detection of waves by a double-pulse laser can be used to identify the closed orbits in the system. We demonstrate this phenomenon with a negative hydrogen ion(H^-) by analyzing the total population excited by a double-pulse laser in a timedependent field for different physical parameters. By analyzing the total excited population using a double-pulse laser, we can uncover all the closed orbits existing in the system. We demonstrate that this can be realized by scanning the first pulse position and the time delay between the two pulses.

关键词： double-pulse laser detection of closed orbits photodetachment spectra time-dependent systems

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Effect of Organic manure and Chemical Amendments on Soil Properties and Crop Yield on a Salt Affected Entisol

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Pedosphere 2005年第1期15卷 46-51页

作者： A.u.BHATTI Q.khan A.H.GuRmANI m.J.khan DepartmentofSoilandEnvironmentalSciences NWFPAgriculturalUniversityPeshawarPakistan AridZoneResearchInstitute DeralsmailKhanNWFPPakistan

A field experiment was conducted for two consecutive years in a farmer's field at Haji mora Village, Dera Ismail khan (D.I. khan) in the Northwest Frontier Province (NWPP) of Pakistan to compare various management practices, such as the effect of various organic manures and gypsum in a rice-wheat cropping system on a saline-sodic Entisol (Zindani soil series). The treatments consisted of 1) a control (rice-wheat), 2) gypsum, 3) farmyard manure (FYm), 4) berseem (Trifolium alexzndrinum L.) as green manure (Gm), and 5) dhancha (Sesbania sp.) as Gm. All treatments increased yields of both rice and wheat significantly (P manure treatments proving more economical than the others; while they decreased pH, electrical conductivity (EC), and sodium adsorption ratio (SAR) of the soil. Saturation percentage and available water of the soil were raised for all treatments due to an increase in organic matter content of the soil.

关键词： berseem dhancha farm yard manure gypsum saline-sodic Entisol

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Experimental investigation of evaporative cooling systems for agricultural storage and livestock air-conditioning in Pakistan

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Building Simulation 2021年第3期14卷 617-631页

作者： Hafiz m.u.Raza muhammad Sultan majid Bahrami Alamgir A.khan Department of Agricultural Engineering Bahauddin Zakariya UniversityBosan RoadMultan 60800Pakistan Laboratory for Alternative Energy Conversion(LAEC) School of Mechatronic Systems EngineeringSimon Fraser UniversitySurreyBCCanada Department of Agricultural Engineering Muhammad Nawaz Shareef University ofAgricultureMultan 60000Pakistan

Evaporative cooling(EC)is an ancient technique that is usually suitable for hot and dry climatic conditions due to the potential of water vapor *** this study,three kinds of evaporative cooling systems such as direct EC(DEC),indirect EC(IEC),and maisotsenko cycle EC(mEC)were locally developed at *** performance of the systems was evaluated and compared for agricultural storage and livestock air-conditioning application in *** experiments were performed for climatic conditions of multan city(Pakistan)and the data were collected for hourly and daily *** to the results,it was observed that the DEC system has the ability to reduce the temperature of ambient air to an average of 8.5℃.Whilst IEC and mEC systems were able to drop the temperature of ambient air to an average of 6.8℃and 8.9℃,*** per the results,the DEC system remained behind to provide desired conditions for livestock and agricultural product storage applications due to excessive *** the other hand,the IEC and mEC systems can achieve the desired conditions for livestock application,but could not provide feasible conditions for various fruits and vegetable *** study concludes that hybrid EC systems can be developed to provide desired conditions for a wide range of applications under varying climatic conditions.

关键词： evaporative cooling air-conditioning dew-point wet-bulb storage livestock

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Effect of Precursor mechanism on CO-NO Catalytic Reaction on Body-Centred Cubic Structure： monte Carlo Simulation

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Chinese Physics Letters 2005年第9期22卷 2422-2425页

作者： A. u. Qaisrani m. Khalid m. K. khan Department of Physics Gomal University Dera Ismail Khan Pakistan Department of Physics Quaid-i-Azam University Islamabad Pakistan

The CO-NO catalytic reaction on body-centred cubic （bcc） lattice is studied by monte Carlo simulation. The simple Langmuir-Hinshelwood （LH） mechanism yields a steady reactive window, which is separated by continuous and discontinuous irreversible phase transitions. The effect of precursor mechanism on the phase diagram of the system is also studied. According to this mechanism, the precursor motion of CO molecules is considered only on the surface of bcc lattice. Some interesting observations are reported.

关键词： KINETIC PHASE-TRANSITIONS SuRFACE-REACTION mODEL SuBSuRFACE OXYGEN HEXAGONAL SuRFACES SQuARE LATTICE REDuCTION PLATINum PT(100) O-2

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Improving Acacia auriculiformis seedlings using microbial inoculant(Beneficial microorganisms)

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Journal of Forestry Research 2014年第2期25卷 359-364页

作者： Bayezid m.khan m.K.Hossain m.A.u.mridha Assistant Professor Institute of Forestry & Environmental SciencesUniversity of Chittagong Institute of Forestry & Environmental Sciences University of Chittagong Plant Production Department King Saud University

A microbial inoculant, known as effective microorganisms （Em）, was applied to determine its efficacy on seed germination and seedling growth in the nursery of Acacia auriculiformis A Curm. ex Benth. The seedlings were grown in a mixture of sandy soil and cow dung （3：1） and kept in polybags; Em was poured at different concentra- tions （0.1%, 0.5%, 1%, 2%, 5% and 10%）. Seed germination rate and growth parameters of seedlings - shoot and root lengths, fresh and dry weights of shoots and roots, vigor, volume, and quality indices and stur- diness - were measured. The nodulation status influenced by Em was also observed, along with the measurement ofpigrnent contents in leaves. The highest germination rate （72%） was observed in 2% Em solution while the lowest （55%） was found in control treatment. The highest shoot and root lengths （30.6 cm and 31.2 cm respectively） were recorded in 2% Em and were significantly （p 〈0.05） different from control. Both fresh and dry weights of shoots were maximum （8.66 g and 2.99 g respectively） in 2% Em, whereas both fresh and dry weights of root were maximum （2.56 g and 1.23 g respectively） in 5% Em solution. Although the highest vigor index, volume index, and sturdiness （4450, 628 and 67.5 respec- tively） were found in 2% Em, the highest quality index （0.455） was found in 5% Em solution. The nodule number was higher at a very low （0.5%） concentration of Em but it normally decreased with the increase of concentration. The contents of chlorophyll a, chlorophyll b, and carotenoid were maximum （43.26 mg.L-1, 13.56 mg.L-1 and 17.99 mg.L-1 respectively） in 2% Em. Therefore, low concentration of Em （up to 2%）can be recommended for getting maximum seed germination and seed- ling development ofA. auriculiformis in the nursery.

关键词： microbial inoculant (Em) germination seedling vigor leaf's pigment nodulation status.

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Brownian motion and thermophoresis effects on unsteady stagnation point flow of Eyring-Powell nanofluid: a Galerkin approach

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Communications in Theoretical Physics 2020年第12期72卷 71-82页

作者： Z H khan m usman T Zubair m Hamid R u Haq State Key Laboratory of Hydraulics and mountain River Engineering College of Water Resource and HydropowerSichuan UniversityChengdu610065China BIC-ESAT College of EngineeringPeking UniversityBeijing 100871China State Key Laboratory for Turbulence and Complex Systems Department of Mechanics and Engineering SciencePeking UniversityBeijing 100871China Institute of Ocean Research Peking UniversityBeijing 100871China School of mathematical Sciences Peking UniversityBeijing 100871China Department of mechanics and Engineering Science Fudan UniversityShanghai 200433China Department of Electrical Engineering Bahria UniversityIslamabad CampusIslamabad 44000Pakistan

This article concerns the analysis of an unsteady stagnation point flow of Eyring–Powell nanofluid over a stretching *** influence of thermophoresis and Brownian motion is also considered in transport *** nonlinear ODE set is obtained from the governing nonlinear equations via suitable *** numerical experiments are performed using the Galerkin scheme.A tabular form comparison analysis of outcomes attained via the Galerkin approach and numerical scheme(RK-4)is available to show the credibility of the Galerkin *** numerical exploration is carried out for various governing parameters,namely,Brownian motion,steadiness,thermophoresis,stretching ratio,velocity slip,concentration slip,thermal slip,and fluid parameters,and Hartmann,Prandtl and Schmidt *** velocity of fluid enhances with an increase in fluid and magnetic parameters for the case of opposing,but the behavior is reversed for assisting *** Brownian motion and thermophoresis parameters cause an increase in temperature for both cases(assisting and opposing).The Brownian motion parameter provides a drop-in concentration while an increase is noticed for the thermophoresis *** the outcomes and the behavior of emerging parameters are illustrated *** comparison analysis and graphical plots endorse the appropriateness of the Galerkin *** is concluded that said method could be extended to other problems of a complex nature.

关键词： Eyring-Powell fluid stagnation point flow Brownian motion and thermophoresis Galerkin method

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Etch Induction Time in CR-39 Detectors Etched in Na2CO3 mixed NaOH Solution

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Chinese Physics Letters 2009年第9期26卷 105-107页

作者： N. Ali E. u. khan K. khan DPAm PLEAS P.O. Nilore Islamabad Pakistan P.D PINSTECH P.O. Nilore Islamabad Pakistan Department of Physics CIIT Islamabad Pakistan HPD PINSTECH P.O. Nilore Islamabad Pakistan

Six different solutions of 6m NaOH, containing different amounts of Na2CO3 at 70℃ were used for the revelation of latent damage trails in CR-39 plastic track detectors. These detectors were earlier exposed to fission fragments from ^252 Cf source for 30 min in vacuum and were then etched in the respective solutions for different etching time intervals of 5-20 min starting from 5min up to 160min. The etch induction time in each detector was obtained by extrapolating the intersection of resulting curves of track lengths and track diameters with the time axis.

关键词： No English Keyword

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Effect　of　Ballistic-Type　Hot　Atom　Adsorption　mechanism　on　the　Phase　Diagram　of　monomer　Dimer　CO-O2　Surface　Catalytic　Reaction：　A　monte　Carlo　Simulation

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Chinese Physics Letters 2004年第6期21卷 1171-1174页

作者： m.Khalid K.m.khan A.u.Qaisrani Q.N.malik DepartmentofPhysics GomalUniversityDeraIsmailKhanPakistan NuclearPhysicsDivision PakistanInstituteofNuclearScienceandTechnology(PINSTECH)P.O.NiloreIslamabadPakistan

We investigate the effect of the ballistic mechanism on the phase diagram using a square surface. While using this mechanism whenever an O2 molecule hits a randomly vacant selected site, the molecule breaks up into atomic form and then executes a ballistic flight. The paths of the two oxygen atoms are taken exactly to be opposite to each other, ***-parallel, and the ranges of the atoms are taken to be equal, *** may fly up to 1 or 1.414 or 2 of the atomic spacing from the site of impact. Four cases have been studied on the basis of the range of hot atoms. The range of the hot oxygen atoms executing a ballistic flight might be up to the first nearest neighbourhood (1 atomic spacing from the site of impact), the second nearest neighbourhood (1.414 atomic spacing from the site of impact), the third nearest neighbourhood (2 atomic spacing from the site of impact), known as cases a, b, and c, respectively, while for case d the range of the oxygen atoms executing the ballistic flight might be up to 1 atomic spacing or 1.414 atomic spacing or 2 atomic spacing from the site of impact. The steady reactive window is observed and the continuous transition disappears. As soon as the CO partial pressure departs from zero, the production of CO2 is observed, which clearly verifies the experimental observation.

关键词： Oxygen

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