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      • KCI등재

        Adaptive Fractional Order PID Controller Based MPPT for PV Connected Grid System Under Changing Weather Conditions

        Nasir Ali,Rasool Imran,Sibtain Daud,Kamran Raheel 대한전기학회 2021 Journal of Electrical Engineering & Technology Vol.16 No.5

        This paper is presenting an Adaptive Fractional Order PID (AFOPID) controller for PV connected grid system. The proposed controller is designed to harvest maximum power from the PV source. AFOPID controller contain the property of conventional PID controller, where the controller contains an adaptive property to optimize gain parameter on the basis of generator and grid side parameter in view. In the suggested work, the AFOPID controller imparted with the characteristic to get tune with particle swarm optimization to track maximum power point tracking, dc link voltage, and current control and quadrature axis modeling. Furthermore, the current control functionalities are performed through an AFOPID, where the controlling parameters are updated by measured error at every instant. The aim of this research is to attain maximum power from the PV source under varying weather conditions with minimum total harmonic distortion, which validate the performance of the proposed controller. The proposed work is compared with, FOPID, FLC, PI, GA and ACO tune FOPID controllers.

      • Path-Following Algorithms for Beamforming and Signal Splitting in RF Energy Harvesting Networks

        Nasir, Ali A.,Tuan, Hoang D.,Ngo, Duy T.,Durrani, Salman,Kim, Dong In IEEE 2016 IEEE COMMUNICATIONS LETTERS Vol.20 No.8

        <P>We consider the joint design of transmit beamforming and receive signal-splitting ratios in the down-link of a wireless network with simultaneous radio frequency information and energy transfer. Under constraints on the signal-to-interference-plus-noise ratio at each user and the total transmit power at the base station, the design objective is to maximize either the sum harvested energy or the minimum harvested energy. We develop a computationally efficient path-following method to solve these challenging nonconvex optimization problems. We mathematically show that the proposed algorithms iteratively progress and converge to locally optimal solutions. Simulation results further show that these locally optimal solutions are the same as the globally optimal solutions for the considered practical network settings.</P>

      • KCI등재

        Experimental and numerical characterization of mechanical properties of carbon/jute fabric reinforced epoxy hybrid composites

        Aakash Ali,Muhammad Ali Nasir,Muhammad Yasir Khalid,Saad Nauman,Khubab Shaker,Shahab Khushnood,Khurram Altaf,Muhammad Zeeshan,Azhar Hussain 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.9

        Natural fiber composites have great potential for reducing the product cost, lowering weight and enhancing renewability. Functionality and performance of natural fibers can be enhanced many folds using them together with synthetic fibers. Hybridization of carbon and low-cost natural jute fiber offers a sustainable hybrid composite having high modulus and mechanical strength. This study investigates flexural behavior of carbon/jute epoxy composites experimentally and numerically. Also, impact response is characterized through drop weight method. Study concludes that flexural strength decreases with increase in jute percentage. Simulation of flexural behavior diverges more than 10 % from experimental results. This anomaly is due to waviness of fiber resulting in heterogeneous property distribution in composites. Further, the fracto-graphic study revealed modes of failure. The drop weight impact tests reveal increased damage area with increase in jute percentage.

      • KCI등재후보

        Enhanced recovery after hepatopancreaticobiliary surgery: A single-center case control study

        Fakhar Nasir,Zeeshan Hyder,Amir Kasraianfard,Ali Sharifi,Abdolhamid Chavoshi Khamneh,Seyed Yahya Zarghami,Ali Jafarian 한국간담췌외과학회 2021 Annals of hepato-biliary-pancreatic surgery Vol.25 No.1

        Backgrounds/Aims: The aim of this study was to find the safety and effectiveness of enhanced recovery after surgery (ERAS) in patients who undergo hepatopancreaticobiliary (HPB) surgeries and its association with the postoperative complications and survival rate of the patients. Methods: This study was conducted on patients who underwent HPB surgeries in Imam Khomeini Hospital Complex, Iran from 2018 to 2020. Patients who underwent surgery after from 2019 to February 2020 considered as the ERAS group (n=47) in which ERAS was implemented postoperatively including removing nasogastric tube and initiating surgical diet at 6 hours post operation, and removing intraabdominal drains and Foley catheter at postoperative day one. Other patients (n=43) were considered as the control group in which conventional postoperative care was implemented. Results: Ninety patients with the mean age of 47.3±13.3 yrs/old (range=17-76) including 39 females were enrolled into the study. There were no significant differences between the demographic and preoperative comorbidities between the two groups. Pain severity of the patients in the ERAS group was significantly lower than the control group (visual analogue scales of 3.4±0.77 vs. 4.47±0.88, p<0.001). However, there were no significant differences between the other postoperative data between the two groups. One patient in each group died during hospitalization period due to myocardial infarction. Conclusions: ERAS may be safe and effective in patients who undergo HPB surgery and may be associated with less severe postoperative pain.

      • SCIESCOPUS

        Performance assessment and multi objective optimization of an Organic Rankine Cycle driven cooling air conditioning system

        Nasir, Muhammad Tauseef,Ali, Muhammad Ansab,Khan, Tariq S.,Al-Hajri, Ebrahim,Kadri, Muhammad Bilal,Kim, Kyung Chun Elsevier Sequoia S.A 2019 Energy and buildings Vol.191 No.-

        <P><B>Abstract</B></P> <P>Present work aims to investigate the thermal performance assessment of different combinations of working fluids for an Organic Rankine Cycle powered Vapor Compression Cycle (ORC-VCC) for air-conditioning applications. Analysis of system performance is conducted for a fixed cooling load of a small conditioned space having a sensible heat factor of 0.7, at different ambient conditions. A preliminary evaluation of the system at the baseline conditions was conducted considering the second law efficiency, overall heat capacity of exchangers, overall internal exergy destruction, and overall Coefficient of Performance. Afterwards, parametric study was performed for the best performing candidates from the preliminary analysis using second law efficiency and overall heat capacity of heat exchangers. The system parameters considered for the study include saturated temperatures of heat exchangers, ORC boiler superheat, pinch points and the sub-cooling of both the ORC and VCC condensers. Then, multi objective optimization was performed using Genetic Algorithm followed by multi-criteria decision-making using Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) to select the best optimal solutions from the Pareto front. Sixteen combinations comprising of four working fluids, R245fa, R600, R600a, and R134a were analyzed. The optimization results showed R245fa ORC-R600a VCC to be the best candidate at ambient conditions of 30 °C, while at 35 °C and 40 °C, R600a ORC-R245fa VCC was found to be the most suitable candidate.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The prospects of different working fluids and their combinations in an ORC driven air conditioning system are investigated. </LI> <LI> Ambient conditions considering the outdoor temperatures of 30 °C, 35 °C and 40 °C with 50% relative humidity is selected. </LI> <LI> Working fluids R245fa, R134a, R600a, and R600, and their combinations are the investigated. </LI> <LI> Sensitivity analysis of different parameters on the second law efficiency and UA values of heat exchangers is evaluated. </LI> <LI> Multi-objective optimization of the exergetic efficiency and the UA values of heat exchangers is carried out. </LI> </UL> </P>

      • KCI등재

        Comparative evaluation of gastroulcerogenic potential of nitrogen isoforms of salicyl alcohol and aspirin in rats: biochemical and histological study

        Ali, Gowhar,Subhan, Fazal,Islam, Nazar Ul,Ullah, Nasir,Shahid, Muhammad,Ullah, Sami,Ullah, Ihsan,Shah, Rehmat,Khan, Ikhtiar,Sewell, Robert D. E.,Abbas, Ghulam 대한약학회 2014 Archives of Pharmacal Research Vol.37 No.7

        The aim of the current study was to explore in vivo any relative gastroulcerogenic prospective propensity of newly synthesized nitrogen containing derivatives of salicyl alcohol; compound (I) [1-(2-hydroxybenzyl) piperidinium chloride], compound (II) [4-carbamoyl-1-(2- hydroxybenzyl)piperidinium chloride] and aspirin in albino rats. The experimental groups received the following oral treatments daily for 6 days: group I saline control; group II, standard (aspirin) treatment group [150 mg/kg of body weight]; group III, test (compound I) treatment group [100, 150 mg/kg]; group IV, test (compound II) treatment group [100, 150 mg/kg]. The results showed that in the case of the aspirin treated group and compound (I) [150 mg/kg], there was a significant increase in gastric volume, free acidity, total acidity, ulcer score and a decrease in gastric pH. Furthermore, histopathological examination of gastric mucosa of these treated groups revealed detectable morphological changes. Utilizing the same protocol, synthetic compound (I) [100 mg/kg] and (II) [100, 150 mg/kg] exhibited no statistically significant ulcerogenic or cytotoxic properties. A cyclooxygenase (COX) selectivity test indicated the preferential inhibition of COX-I and COX-II enzymes by compounds (I) and (II). This study therefore indicates that these synthetic compounds may possess reduced ulcerogenic potential and could be a functional substitute to aspirin.

      • KCI등재

        Larvicidal activity of acetone extract and green synthesized silver nanoparticles from Allium sativum L. (Amaryllidaceae) against the dengue vector Aedes aegypti L. (Diptera: Culicidae)

        Nasir Shabab,Walters Keith F.A.,Pereira Roberto M.,Waris Muhammad,Ali Chatha Awais,Hayat Munawar,Batool Marriam 한국응용곤충학회 2022 Journal of Asia-Pacific Entomology Vol.25 No.3

        Mosquito vectors of major human diseases are currently controlled using chemical and biological products. Extensive insecticide use has led to resistance development and human/environmental health risks, and alter native sustainable control options are needed; in this study, activity of an extract of garlic (Allium sativum; Amaryllidaceae), and silver nanoparticles (AgNPs) synthesized from the extract, were evaluated against 2nd and 3rd instar larvae of the yellow fever mosquito, Ae. aegypti (Diptera: Culicidae). Synthesis of AgNPs was confirmed using UV–Vis spectroscopy, and characterised using powdered X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy. Larvae were exposed to five concentrations (50, 100, 150, 200, 250 ppm) of garlic extract or synthesized AgNPs, with distilled water and silver nitrate solution (1 mM) as controls. The mortality of larvae was recorded after 6, 12, 24, 36, and 48 h following addition of the respective extracts. Dose- and time-dependent toxicity were recorded in both treatment groups with no mortality in control groups. Exposure to AgNPs at 250 ppm for 48 h yielded 100% mortality for both larval instars, with corre sponding LC 50 values of 44.77 (2nd) and 62.82 ppm (3rd). Exposure to garlic extract resulted in similar 48-hour mortality (99 ± 0.77% (2nd) and 98 ± 1.10% (3rd), but consistently higher LC 50 values after all exposure times compared to AgNPs (e.g. 48-hour exposure: 108.42 ppm (2nd), 129.11 ppm (3rd), suggesting that AgNPs may potentially be used at lower concentrations for Ae. aegypti control.

      • KCI등재

        Spatio-Temporal Variability of SummerMonsoon Onset over Pakistan

        Shaukat Ali,Bushra Khalid,Rida Sehar Kiani,Romaisa Babar,Sana Nasir,Nadia Rehman,Muhammad Adnan,Muhammad Arif Goheer 한국기상학회 2020 Asia-Pacific Journal of Atmospheric Sciences Vol.56 No.1

        Pakistan receives huge amount of rainfall during summer monsoon season that provides water replenishment for transition periods, helps in maintaining natural and anthropogenic ecosystems, and increased crop productivity. In this changing world, shifts in summer monsoon onset in Pakistan have been observed that seems to affect the society in general. Therefore, it is vital to address these summer monsoon onset shifts to help policy makings and implementation. The study was carried out to analyse the spatio-temporal variability in summer monsoon onset in four objectively defined regions covering all Pakistan. A total of 35 meteorological stations spreading over four regions (i.e., northern, central east, central west, and southern) were taken in to account and shifts in summer monsoon onset have been calculated for the period of 1971–2010. The analysis is based on the observational data of daily precipitation from 20th Jun-20th July for 40 years. The onset for each year and mean onset for each decade has been calculated for all stations. The data was analysed for homogeneity, spatial and temporal variability of monsoon rainfall has been calculated for all four regions, and station wise monsoon onset has been discussed in detail. The temporal analysis shows that the onset of monsoon has shift towards earlier onset from first week of July to last week of June at most of the stations in which the investigation was carried out during the studied period. The spatial analysis shows that the amount of monsoon precipitation during the onset period has decreased after 1970’s in almost all regions. This variability in monsoon onset can have major impacts on rain fed agriculture and cultivation of crops like maize, soybean, rice and sugarcane etc. and will have to revisit the cropping calendar.

      • KCI등재

        Synthesis of Novel Quinoxalinone Derivatives by Conventional and Microwave Methods and Assessing their Biological Activity

        Waqar Nasir,Munawar Ali Munawar,Ejaz Ahmed,Ahsan Sharif,Saeed Ahmed,Amjad Ayub,Misbahul Ain Khan,Faizul Hassan Nasim 대한약학회 2011 Archives of Pharmacal Research Vol.34 No.10

        In this study, twenty-one arylaminoquinoxalinone derivatives were synthesized and their antibacterial activities against Staphylococci aureus, Pseudomonas aureus, Escherichia coli, Bacillus subtilis, Salmonella typhi, and Shigella pneumoniae were evaluated relative to known antibiotics; augmentin, ampicillin, and chloramphenicol. The insecticidal activities of the prepared compounds were also investigated against Tribolium castaneum using permethrin as a standard insecticide. The derivatives were synthesized using both conventional and microwave techniques. Their structures were confirmed using spectral techniques and elemental analysis.

      • KCI등재

        Comparative evaluation of gastroulcerogenic potential of nitrogen isoforms of salicyl alcohol and aspirin in rats: biochemical and histological study

        Gowhar Ali,Fazal Subhan,Nazar Ul Islam,Nasir Ullah,Muhammad Shahid,Sami Ullah,Ihsan Ullah,Rehmat Shah,Ikhtiar Khan,Robert D. E. Sewell,Ghulam Abbas 대한약학회 2014 Archives of Pharmacal Research Vol.37 No.7

        The aim of the current study was to explorein vivo any relative gastroulcerogenic prospective propensityof newly synthesized nitrogen containing derivativesof salicyl alcohol; compound (I) [1-(2-hydroxybenzyl)piperidinium chloride], compound (II) [4-carbamoyl-1-(2-hydroxybenzyl)piperidinium chloride] and aspirin in albinorats. The experimental groups received the following oraltreatments daily for 6 days: group I saline control; group II,standard (aspirin) treatment group [150 mg/kg of bodyweight]; group III, test (compound I) treatment group [100,150 mg/kg]; group IV, test (compound II) treatment group[100, 150 mg/kg]. The results showed that in the case of theaspirin treated group and compound (I) [150 mg/kg], therewas a significant increase in gastric volume, free acidity,total acidity, ulcer score and a decrease in gastric pH. Furthermore, histopathological examination of gastricmucosa of these treated groups revealed detectable morphologicalchanges. Utilizing the same protocol, syntheticcompound (I) [100 mg/kg] and (II) [100, 150 mg/kg]exhibited no statistically significant ulcerogenic or cytotoxicproperties. A cyclooxygenase (COX) selectivity test indicatedthe preferential inhibition of COX-I and COX-IIenzymes by compounds (I) and (II). This study thereforeindicates that these synthetic compounds may possessreduced ulcerogenic potential and could be a functionalsubstitute to aspirin.

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