46 results on '"Abdullah Khan"'
Search Results
2. Fabrication of pectin-based stimuli responsive hydrogel for the controlled release of ceftriaxone
- Author
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Sadaf Hafeez, Atif Islam, Abdullah Khan Durrani, Muhammad Taqi Zahid Butt, Shabnam Rehmat, Asma Khurshid, and Shahzad Maqsood Khan
- Subjects
General Chemical Engineering ,Materials Chemistry ,General Chemistry ,Biochemistry ,Industrial and Manufacturing Engineering - Published
- 2022
3. Petrography and diagenesis of Neoproterozoic Bhander Sandstones, Vindhyan Supergroup, Southeastern Rajasthan, India: Implications for provenance and reservoir characteristics
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Tahreer Ayaz, Mujeebul Hasan, and Abdullah Khan
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General Medicine - Published
- 2023
4. A prospective study on linking diarrheagenic E. coli with stunted childhood growth in relation to gut microbiome
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Israr Aziz, Zobia Noreen, Umer Zeeshan Ijaz, Ozan Gundogdu, Muhammad Haroon Hamid, Nazir Muhammad, Abdullah Khan, and Habib Bokhari
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Multidisciplinary - Abstract
Stunted growth is an emerging global challenge affecting children under the age of 5 years in low- and middle-income countries. Despite such a high global prevalence of stunting, the mechanism of pathogenesis and the role of associated gut microbiota is poorly understood. The present study was designed to investigate the association of pathogenic strains of E. coli with the residential gut microbiota of stunted growth children. A total of 64 stool sample were collected from children aged ≤ 5 years, and were processed for isolation and molecular characterization of diarrheagenic E. coli. Selected stool samples (n = 39 including three normal controls) were then analysed for microbial community profiling using 16S ribosomal RNA (rRNA) gene sequencing. Furthermore, associations between changes in the microbiota in the presence of different E. coli strains was explored. Pathotyping of the isolated E. coli (n = 64) has shown that 39.68% belonged to one of the five pathotypes of E. coli whilst the remaining ones were non-typeable. Amongst the different pathotypes, EPEC was found to be the most prevalent (52%; n = 13), followed by EAEC (20%; n = 5), EIEC (12%; n = 3), EHEC (8%; n = 2) and ETEC 2 (8%; n = 2). Phylogrouping analysis has shown that majority of the strains belonged to B2 (28.12%). Microbial diversity is shown to be significant and varied when the samples are organized under the recovered phylogroups. Moreover, based on predictive metabolism, the colonization of these strains were found to be significantly associated with energy utilization pathways such as Denovoprine-2 and glyoxylate-by. Differential analysis has shown that Escherichia-Shigella and Enterococcus were altered for the children with stunted growth.
- Published
- 2023
5. Response of soil nutrients, enzyme activities, and fungal communities to biochar availability in the rhizosphere of mountainous apple trees
- Author
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Rafiq Ahmad, Jianen Gao, Wenzheng Li, Yuanyuan Zhang, Zhe Gao, Abdullah Khan, Izhar Ali, Saif Ullah, and Shah Fahad
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Soil Science ,Plant Science - Published
- 2023
6. Large piezoelectric response in a Jahn-Teller distorted molecular metal halide
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Sasa Wang, Asif Abdullah Khan, Sam Teale, Jian Xu, Darshan H. Parmar, Ruyan Zhao, Luke Grater, Peter Serles, Yu Zou, Tobin Filleter, Dwight S. Seferos, Dayan Ban, and Edward H. Sargent
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Multidisciplinary ,General Physics and Astronomy ,General Chemistry ,General Biochemistry, Genetics and Molecular Biology - Abstract
Piezoelectric materials convert between mechanical and electrical energy and are a basis for self-powered electronics. Current piezoelectrics exhibit either large charge (d33) or voltage (g33) coefficients but not both simultaneously, and yet the maximum energy density for energy harvesting is determined by the transduction coefficient: d33*g33. In prior piezoelectrics, an increase in polarization usually accompanies a dramatic rise in the dielectric constant, resulting in trade off between d33 and g33. This recognition led us to a design concept: increase polarization through Jahn-Teller lattice distortion and reduce the dielectric constant using a highly confined 0D molecular architecture. With this in mind, we sought to insert a quasi-spherical cation into a Jahn-Teller distorted lattice, increasing the mechanical response for a large piezoelectric coefficient. We implemented this concept by developing EDABCO-CuCl4 (EDABCO = N-ethyl-1,4-diazoniabicyclo[2.2.2]octonium), a molecular piezoelectric with a d33 of 165 pm/V and g33 of ~2110 × 10−3 V m N−1, one that achieved thusly a combined transduction coefficient of 348 × 10−12 m3 J−1. This enables piezoelectric energy harvesting in EDABCO-CuCl4@PVDF (polyvinylidene fluoride) composite film with a peak power density of 43 µW/cm2 (at 50 kPa), the highest value reported for mechanical energy harvesters based on heavy-metal-free molecular piezoelectric.
- Published
- 2023
7. The Role of Vitamin D Supplementation Before Coronary Artery Bypass Grafting in Preventing Postoperative Atrial Fibrillation in Patients With Vitamin D Deficiency or Insufficiency: A Systematic Review and Meta-Analysis
- Author
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Saad Ali Ansari, Jasninder Singh S Dhaliwal, Yusra Ansari, Sudeshna Ghosh, and Tahir Muhammad Abdullah Khan
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General Engineering - Published
- 2023
8. Development and characterization of a new riveting process for pre-drilled holes hard-to-access aircraft riveted joints
- Author
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Haris Ali Khan, Nafey Zafar, Asad Hameed, Farooq Akram, Kamran Asim, Saad Javaid, and Abdullah Khan
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Control and Systems Engineering ,Mechanical Engineering ,Industrial and Manufacturing Engineering ,Software ,Computer Science Applications - Published
- 2022
9. Biochar and Selenium Nanoparticles Induce Water Transporter Genes for Sustaining Carbon Assimilation and Grain Production in Salt-Stressed Wheat
- Author
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Mona H. Soliman, Ghalia S. H. Alnusairi, Amir Abdullah Khan, Taghreed S. Alnusaire, Marwa A. Fakhr, Awatif M. Abdulmajeed, Heshmat S. Aldesuquy, Muhammad Yahya, and Ullah Najeeb
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fungi ,food and beverages ,Plant Science ,Agronomy and Crop Science - Abstract
In a controlled environment experiment, we studied how physiological changes in leaves during the vegetative phase regulate final grain yield of wheat crops in salt-affected soils. We also hypothesized that amendments such as biochar (SB) and selenium-chitosan nanoparticles (Se-NPs) can protect wheat plants from salt injury. 20-day-old wheat plants were submitted to 4-week salt stress (3000 ppm NaCl). Soybean straw biochar was mixed with soil media at planting and Se-NPs (30 ppm) was sprayed 5 days after the first salt stress treatment. At the end of 4-week Se-NPs treatment, one set of plants was harvested for studying leaf level physiological changes. The salt-stressed plants accumulated significantly high leaf Na+ (~ 13-fold increase), which trigged oxidative and osmotic damage. This salt-induced cellular injury was evident from significantly high levels of lipid membrane peroxidation and inhibited photosynthesis. Our study suggested that leaf physiological impairment in wheat plants was translated into poor biomass production and grain yield loss at crop maturity. Compared with control, salt-stressed plants produced 43% lesser biomass during vegetative phase, and 62% lesser grain yield at maturity. Amendments such as SB and Se-NPs protected the plants from salt-induced cellular injury by restricting Na+ transport toward leaf tissues. Plants treated with NaCl + SB + Se-NPs accumulated 50% less Na+ concentrations in leaves compared with NaCl-treated plants. Our study also suggested that SB and Se-NPs can restore ionic homeostasis and carbon assimilation in salt-stressed wheat by upregulating key transporter genes in leaves.
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- 2022
10. Fabrication of pectin-based stimuli responsive hydrogel for the controlled release of ceftriaxone
- Author
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Hafeez, Sadaf, primary, Islam, Atif, additional, Durrani, Abdullah Khan, additional, Butt, Muhammad Taqi Zahid, additional, Rehmat, Shabnam, additional, Khurshid, Asma, additional, and Khan, Shahzad Maqsood, additional
- Published
- 2022
- Full Text
- View/download PDF
11. Yttrium Doped Bismuth Vanadate Titania Heterojunction for Efficient Photoreduction of Cr from Wastewater Under Visible Light
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Uswa Zahoor, Muhammad Imran Rameel, Ahad Hussain Javed, Muhammad Abdullah Khan, Jehan Y. Al-Humaidi, Sajid Iqbal, Afrah Mohammed Aldawsari, and Afzal Shah
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General Environmental Science - Published
- 2022
12. Biochar in Combination with Nitrogen Fertilizer is a Technique: To Enhance Physiological and Morphological Traits of Rice (Oryza sativa L.) by Improving Soil Physio-biochemical Properties
- Author
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Izhar Ali, Amanullah, Ligeng Jiang, Ihsan Muhammad, Anas Iqbal, Asad Ali Khan, Saif Ullah, Quan Zhao, Abdullah Khan, He Liang, Ke Wu, and Jing Zhang
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Soil health ,Oryza sativa ,biology ,Chemistry ,chemistry.chemical_element ,Biomass ,Plant Science ,Photosynthesis ,Nitrate reductase ,Nitrogen ,Agronomy ,Biochar ,biology.protein ,Agronomy and Crop Science ,Glutamine oxoglutarate aminotransferase - Abstract
The over use of synthetic nitrogen (N) fertilizers is the major anthropogenic cause of low N-use efficiency and environmental damage in wetland rice production. Biochar (B) addition to soil is suggested as a climate change mitigation tool that supports carbon sequestration and reduces N losses and greenhouse gas emissions from the soil. Therefore, this study assessed the effect of four levels of B (0, 10, 20 and 30 t ha−1) combined with two levels of N (135 and 180 kg ha−1) on soil health, roots dynamics, physiological attributes, and yield components of rice. The addition of B at 30 t ha−1 combined with 135 N kg ha−1 increased chlorophyll content, net photosynthetic rate, biomass, and grain yield by 104%, 64%, 12%, and 30%, respectively, over control. Further, root traits such as total root length (TRL), total root volume (TRV), total root surface area (TRSA), and total average root diameter (TARD) were improved under 30 t ha−1 combined with 135 N kg ha−1 by 20%, 13%, 13%, and 25%, respectively, than non-biochar treatment under lower N application. Improvements in these traits resulted from higher N uptake due to improved soil physiochemical properties and soil microbial biomass combined with biochar. Interestingly, enhanced N metabolizing enzyme activities, including nitrate reductase (NR), glutamine synthetase (GS), and glutamine oxoglutarate aminotransferase (GOGAT) in biochar-treated plots, further supported the increases in these traits. Our results revealed that the integration of 30 t B ha−1 with 135 kg N ha−1 is a favorable option for enhancing soil health and rice grain yield.
- Published
- 2021
13. There is no definite consensus on the adequate radiographic correction in arthroscopic osteochondroplasty for femoroacetabular impingement: a systematic review and meta-analysis
- Author
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Andrew Duong, Dan Cohen, Marc R. Safran, Olufemi R. Ayeni, Abdullah Khan, Mahmoud Almasri, Jeffrey Kay, Nicole Simunovic, and David Slawaska-Eng
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030222 orthopedics ,medicine.medical_specialty ,Sports medicine ,business.industry ,Radiography ,MEDLINE ,030229 sport sciences ,medicine.disease ,03 medical and health sciences ,0302 clinical medicine ,Pooled variance ,Meta-analysis ,Orthopedic surgery ,Medicine ,Orthopedics and Sports Medicine ,Surgery ,Radiology ,Hip arthroscopy ,business ,Femoroacetabular impingement - Abstract
The purpose of this study is to evaluate and define what is considered an adequate radiographic correction in arthroscopic osteochondroplasty for FAI and to secondarily assess how radiographic outcomes relate to patient reported outcomes and complications. The databases EMBASE, PubMed, and MEDLINE were searched for relevant literature from database inception until January 2021. Studies were screened by two reviewers independently and in duplicate for studies reporting on post-operative radiographic outcomes in arthroscopic osteochondroplasty for FAI. Data on radiographic outcomes as well as data reporting functional outcomes and complications were recorded. A meta-analysis was used to combine the mean pre- and post-operative radiographic outcomes using a random effects model. A risk of bias assessment was performed for all included studies using the MINORS score. The most commonly reported radiographic outcome was the alpha angle with a pooled mean post-operative angle of 44° (95% CI 41°–46°), and mean pre- to post-surgical difference of − 19° (− 22 to − 16, I2 = 96%), followed by the LCEA with a pooled mean post-operative angle of 30° (95% CI 29–31) and mean difference after surgery of − 4° (− 6 to − 1, I2 = 97%,). Eleven studies reported on the correlation between radiographic and clinical outcomes with no consistent consensus correlation found amongst the included studies. Similarly, six studies correlated radiographic outcomes with conversion to THA with no consistent consensus correlation found amongst the included studies. Based on this review, the main conclusion is that there is no consensus definition on the optimal radiographic correction for FAI and there was no consistent correlation between radiographic correction and functional outcomes. However, based on the uniform improvement in functional outcomes, this review suggests a post-operative alpha angle target of 44° with a correction target of 19° and LCEA target of 30° with a correction target of 3°. IV.
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- 2021
14. Spectroscopic and cloud point studies of the interaction and thermodynamics of ciprofloxacin hydrochloride+surfactants mixture in different solvents: Effect of temperature and composition
- Author
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Shamim Mahbub, Mohammad Z. Ahmed, Mezbah Hossain, Ali S. Alqahtani, Omar M. Almarfadi, Md. Mofaqkharur Rahman, Md. Ruhul Amin, Mohammed S. Alqahtani, Md. Anamul Hoque, and Mohammed Abdullah Khan
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Cloud point ,General Chemical Engineering ,Enthalpy ,General Chemistry ,Electrolyte ,Binding constant ,eye diseases ,Gibbs free energy ,chemistry.chemical_compound ,symbols.namesake ,chemistry ,Pulmonary surfactant ,symbols ,Physical chemistry ,sense organs ,Methanol ,Sodium dodecyl sulfate - Abstract
Surfactant is one of the most important chemical entities in drug formulation which can bind with drug molecules. Herein, the binding interaction of ciprofloxacin hydrochloride (CFH) drug with two different surfactants (sodium dodecyl sulfate (SDS) and Triton X-100 (TX-100)) has been investigated through UV-Visible spectroscopic and cloud point measurement techniques at different conditions. The absorption spectrum of CFH was found to be dependent on presence of additives/temperature change. The binding constant (Kb) of CFH+SDS/CFH+TX-100 was found to be increased primarily, reached a maximum value and then decreased with the increase of temperature, except in water medium (pH=2.0) and 30% (v/v) methanol. The Kb values for CFH+SDS were found to be higher in the aqueous medium than almost all medium studied herein, while better binding was observed in the alcoholic medium in the case of the CFH+TX-100 system. The Gibbs free energy of binding (ΔG ) for both CFH+SDS and CFH+TX-100 systems were attained negative in each case studied, inferring the spontaneous binding phenomenon. The cloud point (CP) value of CFH+TX-100 mixture was lessened in ZnSO4·7H2O solution and the CP values exhibited a gradual reduction through the upsurge of electrolyte concentration. The positive values of the Gibbs free energy of clouding indicated the nonspontaneous clouding phenomena. To disclose the interaction between drug and surfactant, other thermodynamic parameters, e.g., enthalpy (ΔH ) and entropy (ΔS ), different transfer energies as well as entropy-enthalpy compensation parameters of binding/clouding were evaluated and clarified with proper explanation.
- Published
- 2021
15. Molybdenum-doped lithium vanadium phosphate (Li3MoxV2−x(PO4)3/C) as cathode material in lithium ion batteries
- Author
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Naseem Iqbal, Muhammad Zulqarnain Arif, Rimsha Mahek, Abdullah Khan, and Tayyaba Noor
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010302 applied physics ,Thermogravimetric analysis ,Materials science ,Scanning electron microscope ,Doping ,chemistry.chemical_element ,Condensed Matter Physics ,Electrochemistry ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,Ion ,chemistry ,Molybdenum ,0103 physical sciences ,Hydrothermal synthesis ,Lithium ,Electrical and Electronic Engineering ,Nuclear chemistry - Abstract
In this work, we report molybdenum-doped lithium vanadium phosphate Li3MoxV2−x(PO4)3/C synthesized using hydrothermal synthesis to be used as potential cathode material for lithium-ion batteries. The structural characterization of the material was done using X-ray diffraction (XRD), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM) which depicted successful incorporation of Mo ion in the Li3V2(PO4)3 structure. Electrochemical properties were studied via constant current charge–discharge cycling. Between the potential range of 2.9–4.3 V, the best sample Li3MoxV2−x(PO4)3/C (x = 0.1) showed the discharge capacities of 152 mAh/g, 130 mAh/g, 110 mAh/g, 90 mAh/g and 70 mAh/g at 0.5C, 1C, 2C, 5C and 10C, respectively. Furthermore, it shows the discharge capacity of 132 mAh/g after 20 cycles at 0.5 C.
- Published
- 2021
16. The enhanced functional traits contribute to the successful invasion of Amaranthus palmeri in salinity environments: a comparison with its congeners
- Author
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Tongtong Wang, Lili Tang, Fuchen Shi, Hongwen Fang, Mei Zhang, Jianhua Han, and Amir Abdullah Khan
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0106 biological sciences ,0301 basic medicine ,Phenotypic plasticity ,Biomass (ecology) ,Specific leaf area ,Cell Biology ,Plant Science ,Biology ,biology.organism_classification ,01 natural sciences ,Biochemistry ,Salinity ,Amaranthus palmeri ,03 medical and health sciences ,Horticulture ,030104 developmental biology ,Congener ,Shoot ,Genetics ,Animal Science and Zoology ,Monoculture ,Molecular Biology ,Ecology, Evolution, Behavior and Systematics ,010606 plant biology & botany - Abstract
Different performance in functional traits between plants can help ecologists to find alien plants successful invasion mechanisms in salinity environments. A pot experiment was conducted to compare 10 functional traits between invasive species Amaranthus palmeri and its co-occuring congener Amaranthus tricolor. Plants grown in the monoculture and co-cultivation types were subjected to four concentrations of NaCl: 0 mM (CK), 75 mM (LS), 150 mM (MS), 200 mM (HS). In monoculture, salinity significantly promoted the growth of A. tricolor. While A. palmeri’s performance decreased due to salinity stress except maximum root length (MRL). In co-cultivation, leaf functional traits of A. tricolor in LS and MS and leaf number (LN), plant height (PH) and biomass (TB) in HS significantly increased. LN and TB of A. palmeri under MS and HS and leaf shape traits, specific leaf area (SLA) and root: shoot ratio (R/S) under LS markedly increased. Almost all functional traits (especially LN, PH, MRL and TB) of A. palmeri were dramatically higher than A. tricolor under co-cultivation, but SLA and R/S relationships were contrary. Functional traits of A. palmeri under co-cultivation were higher than it under monoculture except R/S and leaf shape index (LSI). Moreover, most relative interaction index and relative biomass values of A. palmeri were also higher than A. tricolor in same cultivation types, but phenotypic plasticity index patterns were opposite. Overall, A. palmeri outperforms congeners owing to the enhanced functional traits (superior LN, PH, MRL, TB and lower R/S) related to resource absorption and interception in salt environments.
- Published
- 2021
17. Source rock potential assessment of the Paleocene coal and coaly shale in the Attock-Cherat Range of Pakistan
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Abdullah Khan, Mohibullah Mohibullah, Khalid Latif, Syed Anjum Shah, Irfan U. Jan, Muhammad Younis Khan, Hamid Iqbal, Muhammad Hanif, and Syed Mamoon Siyar
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business.industry ,Coal mining ,Geochemistry ,Maceral ,02 engineering and technology ,010502 geochemistry & geophysics ,Geotechnical Engineering and Engineering Geology ,complex mixtures ,01 natural sciences ,chemistry.chemical_compound ,General Energy ,Inertinite ,020401 chemical engineering ,chemistry ,Liptinite ,Kerogen ,Coal ,0204 chemical engineering ,business ,Vitrinite ,Oil shale ,Geology ,0105 earth and related environmental sciences - Abstract
In this study the hydrocarbon generation potential of the coal and coaly shale samples collected from coal mines in Attock-Cherat Range of Pakistan is optically and analytically evaluated. These samples, representing the Paleocene Hangu Formation, are analyzed across a range of thermal maturity stages to understand their hydrocarbon generation potential. The visual examination of maceral type and values of vitrinite reflectance have been considered while interpreting the geochemical results for the coal and associated sediments from the Paleocene Hangu Formation. The maceral group is dominated by vitrinite, mainly collodetrinite, followed by inertinite and liptinite, and suggests Type III kerogen for the samples. The geochemical parameters suggest that the samples are post mature, however, the vitrinite reflectance measurements show late mature conditions for a gas-prone generation. The overall petrographical and geochemical data suggest that the coal and coaly shale appear to occupy the gas window and fall in the dry gas zone. Based on the maceral types and Rock–Eval data, an anoxic to terrestrial environment is inferred for the deposition of the coal and associated sediments. The vitrinite reflectance, Rock–Eval pyrolysis, and the type and frequency of macerals show that the coal is of good quality, i.e., medium to high volatile bituminous and hard brown coal, mature, and is lying in the gas window. Oxygen index is continuously low throughout the analyzed interval, which further supports that the coal is of good quality.
- Published
- 2021
18. Identification of erosion-prone areas using morphometric parameters, land use land cover and multi-criteria decision-making method: geo-informatics approach
- Author
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Pandurang Choudhari, Ibodullo Qaraev, Luc Cimusa Kulimushi, Md. Abdullah Khan, and Paolenmang Haokip
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Economics and Econometrics ,geography ,geography.geographical_feature_category ,Geography, Planning and Development ,0211 other engineering and technologies ,Drainage basin ,02 engineering and technology ,Land cover ,010501 environmental sciences ,Management, Monitoring, Policy and Law ,Structural basin ,01 natural sciences ,Hotspot (Wi-Fi) ,Ranking ,Natural hazard ,Drainage system (geomorphology) ,Erosion ,Environmental science ,021108 energy ,Physical geography ,0105 earth and related environmental sciences - Abstract
Soil erosion is the main driving force of several devastating natural hazards in the complex mountainous terrain of the Himalayas where the Teesta River basin is located. The present study focused on GIS-based multi-criteria analytical approach (MCA) that integrates morphometric parameters with land cover categories for identification of erosion hotspot areas through sub-watersheds prioritization. The general character of the eight sub-watersheds was derived from the linear, areal and relief aspects, while seven land cover types derived from maximum likelihood classification were evaluated in the MCA. Before combination of the studied parameters in MCA, each parameter was individually ranked and compound value (Cp) was calculated which produced four classes: low, medium, high and very high priority. Later, these ranks were integrated into MCA to give eight major classes classified from 1 to 8. Lowest Cp ranked 1 gets very high priority, while the highest Cp is ranked 8, i.e., lowest priority. The results revealed a predominance of dense forest account for 31.73% of the total area, the basin is a sixth-order river dominated by high relief and marginal slope, elongated in shape, and mean bifurcation ratio (Rb) was 3.879 which indicates an undistorted natural drainage system. Final MCA priority ranking indicated that: SW-4 and 5 having lowest Cp values (3.39 and 4) ranked 1 and 2 suggest very high erosion susceptibility, SW-8 and 3 (4.22 and 4.39) rated 3 and 4, i.e., high priority; SW-6 and 7 ranked 5 and 6, i.e., medium priority; and SW-1 and SW-2 ranked 7 and 8 because of their highest Cp (5.39 and 5.67), i.e., least priority. The prioritization result identified critical areas that are indispensable for sustainable use and management of water and land resources.
- Published
- 2021
19. Cattle dung conversion to syngas: solar photovoltaic integrated gasification system
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Muhammad Ashraf, Naveed Ramzan, Mudassar Azam, Adeel Anwar, Rafi Ullah Khan, Abdullah Khan Durrani, and Muhammad Usman Rashid
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Renewable Energy, Sustainability and the Environment - Published
- 2022
20. Cattle dung conversion to syngas: solar photovoltaic integrated gasification system
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Ashraf, Muhammad, primary, Ramzan, Naveed, additional, Azam, Mudassar, additional, Anwar, Adeel, additional, Khan, Rafi Ullah, additional, Durrani, Abdullah Khan, additional, and Rashid, Muhammad Usman, additional
- Published
- 2022
- Full Text
- View/download PDF
21. GIS-based spatial landslide distribution analysis of district Neelum, AJ&K, Pakistan
- Author
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Shah Naseer, Abdullah Khan, Javed Iqbal Tanoli, Syed Tallataf Hussain Shah, Nangyal Ghani Khan, Tanveer Ul Haq, and Faizan-ur-Rehman Qaiser
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021110 strategic, defence & security studies ,Atmospheric Science ,010504 meteorology & atmospheric sciences ,Mass movement ,Landslide classification ,0211 other engineering and technologies ,Landslide ,02 engineering and technology ,Induced seismicity ,01 natural sciences ,Debris ,Natural hazard ,Earth and Planetary Sciences (miscellaneous) ,Alluvium ,Physical geography ,Digital elevation model ,Geology ,0105 earth and related environmental sciences ,Water Science and Technology - Abstract
The Landslide happens in mountainous regions due to the catastrophe of slope through intensive rain and seismicity. The Himalayas is one of the susceptible parts of the world in the perspective of slope catastrophe hazard; i.e., Mass Movement, especially Neelum valley is considerable destruction of community infrastructure, highway, and critically disturbed the tourism segment. Landslide is a common and recurrent phenomenon in the northern mountainous terrain of Pakistan such as District Neelum. After the 2005 Kashmir earthquake, the importance of landslide investigation is increasing. The purpose of this research is to establish a brief landslide inventory and to determine the relationship of landslides with causative factors by spatial distribution analysis. With the aid of Google Earth imageries and field visits, a total of 618 landslides were identified in the study area of 3621 km. These landslide localities compared with causative factors. Finally, distribution maps are generated and analyse their feature class through Digital Elevation Model and ArcGIS. Landslide intensity is calculated in terms of landslide concentration. Landslide concentration (LC) is significantly found very high in slope gradient less than 30 (1.21) and the first 100 m zone around the road network (15.06). A bit higher landslide frequency is noted in east orienting slopes. In the first 100 m, zone road network and drainage networks are 83.49% and 62.78% of the total landslide occurs having LC value 4.6, respectively. The analysis shows that the steep slopes, an area closer to the road network, drainage network, barren lands, and Quaternary alluvium of loose material are more susceptible to landslides. In addition, a landslide classification map is also prepared on the basis of field observation that shows that debris slides are more dominating.
- Published
- 2021
22. Influence of Different Integrated Nutrient Management Strategies on Growth, Yield and Nutritional Qualities of Cauliflower
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Mohiuddin Ahmed, Rafat Nur Abdullah Khan, Sumaya Farzana, Tahsina Sharmin Hoque, Md. Rafiqul Islam, and Nafise Khodabakhshloo
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0106 biological sciences ,Nutrient management ,Compost ,Field experiment ,Phosphorus ,chemistry.chemical_element ,04 agricultural and veterinary sciences ,Plant Science ,Biology ,engineering.material ,01 natural sciences ,Manure ,Animal science ,Nutrient ,chemistry ,040103 agronomy & agriculture ,engineering ,0401 agriculture, forestry, and fisheries ,Fertilizer ,Agronomy and Crop Science ,Cow dung ,010606 plant biology & botany ,Food Science - Abstract
Organic manures are beneficial in recycling of nutrients into soil and can serve as an alternative to mineral fertilizers. A field experiment was conducted at two locations to evaluate integrated management of different organic manures with chemical fertilizers for cauliflower production. The experiment consisted of seven treatments T0: control, T1: 75% recommended fertilizer dose (RFD), T2: 100% RFD, T3: 75% RFD + Kazi compost (5 t ha−1), T4: 75% RFD + Kazi compost (3 t ha−1), T5: 75% RFD + poultry manure (3 t ha−1) and T6: 75% RFD + cow dung (5 t ha−1). Combined application of organic manures and inorganic fertilizers significantly increased growth parameters, yield attributes and yield of cauliflower and exerted significant positive effects on nutrient [nitrogen (N), phosphorus (P), potassium (K) and sulfur (S)] uptakes by curds compared to the unfertilized control. There was no considerable effect of integrated nutrient management on the occurrence of seed-borne fungi in curds and leaves. Among different treatment combinations, the performance of T3 was the best which was statistically similar with T4. Next to Kazi compost (70% poultry manure composted with 30% rice and/or saw dust), poultry manure performed well followed by cow dung in association with chemical fertilizers. In both of the locations, the performance of integrated nutrient management was better (compensating up to 25% of RFD) compared to sole application of inorganic fertilizers. Therefore, Kazi compost @ 5 t ha−1 combined with 75% RFD should be recommended for better growth, yield and nutritional improvement in cauliflower.
- Published
- 2021
23. Hybrid Nanocomposites of Multi-walled Carbon Nanotubes (MWCNTs) and CuO as Electrode Materials for Energy Storage Devices
- Author
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N.R. Khalid, Aamir Shakoor, Rana M. Arif Khalil, Muhammad Imran, Sungjun Kim, Bushra Choudhry, N. A. Niaz, Muhammad Abdullah Khan, and Fayyaz Hussain
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010302 applied physics ,Materials science ,Nanocomposite ,Coprecipitation ,Composite number ,Oxide ,02 engineering and technology ,Carbon nanotube ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Electrochemistry ,01 natural sciences ,Energy storage ,Electronic, Optical and Magnetic Materials ,law.invention ,chemistry.chemical_compound ,Chemical engineering ,chemistry ,law ,0103 physical sciences ,Materials Chemistry ,Electrical and Electronic Engineering ,Cyclic voltammetry ,0210 nano-technology - Abstract
The search for electrode materials as a potential candidate for Li-ion based batteries is important to achieve high-performance devices. This work constitutes the experimental and theoretical investigation of structural stability and electrochemical behavior of cupric oxide and multi-walled carbon nanotubes (CuO/MWNNTs) nanocomposites. The electrochemical performance of nanocomposites was gauged employing charge/discharge and cyclic voltammetry studies. It is shown that electrochemical properties of pure materials, due to the synergistic effect, are considerably enhanced in CuO/MWNNTs composites. As a result, high rate capability and better cycling stability is observed in CuO-5%MWCNTs samples. In addition, this composite possesses better specific capacity 810 mAh g−1 and a high columbic efficiency of 80.86%. The DFT calculations also confirmed the improved electrochemical properties of MWCNTs in the presence of CuO nanoparticles.
- Published
- 2019
24. Seasonal Variations of Streams Hydrochemistry and Relationships with Morphometric/Landcover Parameters in the Bhagirathi Watersheds, Garhwal Himalaya, India
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Zabiullah Ansari, Mohd. Abdullah Khan, and Sarfaraz Ahmad
- Subjects
Hydrology ,geography ,Watershed ,geography.geographical_feature_category ,Geology ,Glacier ,Land cover ,STREAMS ,010501 environmental sciences ,010502 geochemistry & geophysics ,Snow ,01 natural sciences ,Meltwater ,Surface water ,Groundwater ,0105 earth and related environmental sciences - Abstract
The Bhagirathi streams are a major source of fresh water in the form of glaciers meltwater streams and monsoonal phenomena. The watersheds of the Bhagirathi basin is trending towards water chemistry as well as changing morphological and land cover features due to the climatic and anthropogenic activity. To understand seasonal hydrochemistry and the impact of watershed morphology a total of 32 stream water samples collected during post and pre-monsoon seasons. The bicarbonate is the most dominant ion in the streams water followed by Na+, Ca+2, SO4−2, Cl−, SiO2, K+, and Mg+2. The results were found that HCO3− is in very good correlation with the base cations Ca+2, Mg+2 and Na+ in both pre and post-monsoon seasons. The higher concentration of HCO3− in Bhagirathi stream water and its positive correlation with Ca+2 and Mg+2 indicates that their main source comes from the dissolution of carbonates. Most of the hydro-chemical parameters (EC, pH) and ions (Ca+2, Mg+2, Na+, K+, HCOf−, SO4−2, Cl−, and F−) indicated a relationship with morphometric and land cover and these parameters vary with the season. It is observed that elevation, relief, basin length, area, and perimeter impact on stream water chemistry. Due to the processes of chemical weathering, mixing of the groundwater, snow/glacier meltwater, and surface water components responsible for the seasonal variation in the hydro-chemistry of streams. Impact of agriculture land is more dominant than any land cover followed by barren land and glacier cover that influence the hydrochemistry of streams.
- Published
- 2019
25. Investigation of soil nutrients and associated rhizobacterial communities in different sugarcane genotypes in relation to sugar content
- Author
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Muqing Zhang, Zhengxia Chen, Ziting Wang, Junyao Bu, Muhammad Adnan, and Abdullah Khan
- Subjects
Soil nutrients ,Rhizosphere ,Total root length ,Agriculture ,Root system ,Sugarcane ,Biology ,Rhizobacteria ,Biochemistry ,Horticulture ,Diversity index ,Bacterial diversity ,Alpha diversity ,Microbiome ,Species richness ,Sugar ,Agronomy and Crop Science ,Food Science ,Biotechnology - Abstract
Background Plant microbiomes and soil are bridged by rhizobacteria, maintaining and improving plant health and growth in different aspects. This study was conducted in the field station of the Guangxi University, Fusui, China. We investigated soil nutrients, root morphology and rhizosphere bacterial composition, and community structures in 18 sugarcane genotypes concerning sugar content under the same environmental condition. Results Most of the rhizosphere microbiomes of these genotypes exhibited similar bacterial compositions. However, the evaluated genotypes harbored a significant effect and difference in the abundance of operational taxonomic units and bacterial composition in the rhizosphere compartments. Alpha diversity analysis on the rhizosphere microbiome showed a significant difference in the bacterial diversity (Shannon index, p p p Conclusion The results showed a closely related and highly conserved bacterial community of the rhizosphere microbiome. The rhizosphere microbiome diversity and related bacterial communities were highly associated with the relevant plant taxa, probably at the order level. As a result, it is possible to conclude that the host genotype and the same environmental condition influenced the rhizosphere microbiome via root phenes. Future research regarding plant phenes and microbiome functional groups could be considered an essential factor. Graphic abstract
- Published
- 2021
26. Pyrolysis of cattle dung: model fitting and artificial neural network validation approach
- Author
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Muhammad Ashraf, Abdullah Khan Durrani, Rafi Ullah Khan, Naveed Ramzan, Samreen Ayaz, Umair Aslam, and Zaheer Aslam
- Subjects
Artificial neural network ,Renewable Energy, Sustainability and the Environment ,Chemistry ,Model fitting ,Biological system ,Pyrolysis - Published
- 2021
27. Geological and Geomorphological Characteristics of Hingol National Park (HNP), Balochistan: a Geoheritage Candidate from Southern Pakistan
- Author
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Abdullah Khan, Usman Saeed, Afrasiab Khan, Adnan Ahmad, Muhammad Alamzeb, Abbas Ali Naseem, Jawad Ahmad, Arsalan Ahmad, and Muhammad Yaseen
- Subjects
Tectonics ,Outcrop ,National park ,Earth science ,Geography, Planning and Development ,Earth and Planetary Sciences (miscellaneous) ,Historical geology ,Geotourism ,Geology ,Cretaceous ,Natural (archaeology) ,Nature and Landscape Conservation ,Mud volcano - Abstract
The Hingol National Park, Pakistan, holds complex geological setting due to active geodynamic nature and association of three major tectonic plates, i.e., Eurasian, Arabian, and Indian. The geological and geomorphological characteristics of HNP were studied as a geoheritage candidate form southern Pakistan. The lithological successions exposed in HNP are highly deformed and tectonically thrusted sheets of cretaceous to Paleocene melanges. For the first time, the geoheritage features in the HNP are highlighted and correlated with the criterion (Viii, natural) of UNESCO World Heritage list. Fourteen geological heritage and ten notable geological features are documented in this paper. These features are reported as tectonic, economical, geochemical, paleogeographical, environmental, hydrogeological, sedimentological, paleontological, and geohistorical. HNP maintains global ranking and needs professional knowledge for understating particularly the mechanism behind the geological/geomorphological features. Moreover, the HNP aesthetic properties are high due to the spectacular landscapes specifically princess of hope, sphinx of Baluchistan, beaches, oasis, and mud volcanoes which are collectively discussed as geological resources. The geoheritage diversity described in this research can be proposed as a complex geosite with distinctive geological and geomorphological characteristics due to its excellent quality of outcrops and easy access to the area. These characteristics can be helpful in documenting the scientific and geotourism perspective, making the national park as an important geosite for the better and efficient exploration of geoheritage.
- Published
- 2021
28. Pyrolysis of cattle dung: model fitting and artificial neural network validation approach
- Author
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Ashraf, Muhammad, primary, Aslam, Zaheer, additional, Ramzan, Naveed, additional, Aslam, Umair, additional, Durrani, Abdullah Khan, additional, Khan, Rafi Ullah, additional, and Ayaz, Samreen, additional
- Published
- 2021
- Full Text
- View/download PDF
29. An alternative approach to neural network training based on hybrid bio meta-heuristic algorithm
- Author
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Muhammad Imran, Khalid Shah, Rahmat Shah, Javed Iqbal Bangash, Abdullah Khan, and Asfandyar Khan
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Optimization problem ,General Computer Science ,Artificial neural network ,biology ,Computer science ,Survival of the fittest ,0211 other engineering and technologies ,Swarm behaviour ,Particle swarm optimization ,Computational intelligence ,02 engineering and technology ,biology.organism_classification ,Metaheuristic algorithms ,0202 electrical engineering, electronic engineering, information engineering ,Key (cryptography) ,020201 artificial intelligence & image processing ,Cuckoo search ,Metaheuristic ,Algorithm ,Cuckoo ,021106 design practice & management - Abstract
Metaheuristic algorithms are popular techniques used to solve several optimization problems. Among the key algorithms, cuckoo search (CS) is a comparatively novel and promising metaheuristic algorithm. Various researchers have shown that it performs better when compared to other metaheuristic algorithms while searching for optimal value and is being used to solve various real-world problems. However, the basic CS algorithm can be improved by enhancing the probabilities of survival of the eggs. It will decrease the possibility of the eggs getting ruined by the host bird. The cuckoo birds move to a new position looking for more search space to get better solutions. Furthermore, better search space can be obtained by executing levy flight with accelerated particle swarm optimization (APSO). This research proposes a new method known as hybrid accelerated cuckoo particle swarm optimization (HACPSO) algorithm, based on two metaheuristic algorithms. In the proposed HACPSO algorithm, APSO provides communication for looking better place having the best nest with greater survivability for cuckoo birds. Different simulation has been carried using standard dataset and efficiency of the proposed algorithm is compared with CS, artificial bee colony and other similar hybrid variants. The simulation results demonstrate that the HACPSO algorithm performs better as compared to other algorithms in term of accuracy, MSE, SD, and with fast convergence rate to the target space.
- Published
- 2019
30. Mathematical modeling of magneto-peristaltic propulsion of a viscoelastic fluid through a complex wavy non-uniform channel: an application of hall device in bio-engineering domains
- Author
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Salah Ud-Din Khan, Khurram Javid, Sulaiman Ali Alharbi, Mohsan Hassan, Abdullah Khan, and Shahab Ud-Din Khan
- Subjects
Fluid Flow and Transfer Processes ,Physics ,Curvilinear coordinates ,Partial differential equation ,General Physics and Astronomy ,Relaxation (iterative method) ,02 engineering and technology ,Mechanics ,Hartmann number ,01 natural sciences ,Viscoelasticity ,010305 fluids & plasmas ,Physics::Fluid Dynamics ,020303 mechanical engineering & transports ,0203 mechanical engineering ,Flow (mathematics) ,0103 physical sciences ,Stream function ,Magneto - Abstract
Applications of the Hall device into both the biological and engineering domains have been investigated in the current study. A complex peristaltic driven flow of a viscoelastic fluid is considered through a non-uniform regime having wavy walls under the magnetic and Hall effects. The physical influences of magnetic and Hall parameters on different rheological features of biomimetic propulsion in the wave frame are highlighted in details. Due to the complex nature of the flow regime, the curvilinear coordinates are used in the derivation of continuity and momentum equations. The flow analysis is based on creeping phenomena and long wavelength approximations. Analytical solutions of the governing equations are difficult to obtain due to complicated and complex mathematical form of partial differential equations. Numerical solutions of the governing equations are obtained with the help of the versatile BVP4C command in MATLAB software. The main objective of the current study is to observe the physical behavior of embedded parameters such as dimensionless radius of curvature, Hartmann number (magnetic parameter), Hall parameter, phase difference, non-uniform parameter, and viscoelastic (time relaxation and retardation) parameters on the axial velocity, stream function, pressure gradient, pumping, and trapping phenomena. Moreover, the comparison between viscous and viscoelastic fluids has been argued in detail through graphs. This research work provides comprehensive information about the magnetic and Hall devices, respectively, that are more productive to control the flow of biological fluids through the non-uniform nature of vessels. This study has numerous applications in micro-scale devices of biomedical and industrial domains, cooling systems in nuclear power stations, magnetic therapy, hydrology, physiological drug delivery systems, blood pumping, and micro devices used during surgical treatments.
- Published
- 2021
31. Erratum to: Mathematical modeling of magneto-peristaltic propulsion of a viscoelastic fluid through a complex wavy non-uniform channel: an application of hall device in bio-engineering domains
- Author
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Khurram Javid, Salah Ud-Din Khan, Shahab Ud-Din Khan, Mohsan Hassan, Abdullah Khan, and Sulaiman Ali Alharbi
- Subjects
General Physics and Astronomy - Published
- 2021
32. Channel aware receiver for next generation wireless communication system
- Author
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Muhammad, Asim, primary, Asfandyar, Khan, additional, Javed, Iqbal Bangash, additional, and Abdullah, Khan, additional
- Published
- 2021
- Full Text
- View/download PDF
33. Lead contamination in shooting range soils and its phytoremediation in Pakistan: a greenhouse experiment
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Madiha Azhar, Said Muhammad, Muhammad Jamal Nasir, Sardar Khan, Alia Naz, Shams Ali Baig, Amir Zeb Khan, and Abdullah Khan
- Subjects
Pollution ,010504 meteorology & atmospheric sciences ,biology ,Soil test ,media_common.quotation_subject ,Greenhouse ,Contamination ,Cynodon dactylon ,010502 geochemistry & geophysics ,biology.organism_classification ,01 natural sciences ,Soil contamination ,Phytoremediation ,Agronomy ,Soil water ,General Earth and Planetary Sciences ,Environmental science ,0105 earth and related environmental sciences ,General Environmental Science ,media_common - Abstract
This study investigated the lead (Pb) contamination levels in a military shooting range soil of Nowshera Cantonment, Pakistan. For this purpose, various soil samples were collected from the military shooting range and analyzed for Pb concentration using the atomic absorption spectrometry (Perkin Elmer 1100B, USA). Results demonstrated that soil Pb concentrations ranged from 1 to 193 mg/kg. Soil pollution index values revealed that 42% of sampling sites showed a higher level of pollution and exceeded the limits. The soil of the shooting range was classified into four types based on determined Pb concentration such as control/clean, agriculture soil threshold (50 mg/kg), this study means (62.5 mg/kg), and the highest level (193 mg/kg). The above four types of soils were used to evaluate the phytoremediation potential of indigenous plants like Chenopodium album L. and Cynodon dactylon L. in the greenhouse environment. Results showed that the highest level of Pb was accumulated in plant species exposed to the soil of maximum contamination. Moreover, among the studied plant species, the Cynodon dactylon L. did not exhibit any harmful effects with an increase in Pb contamination. Therefore, the studied plants could be used as a better remedial strategy in Pb-contaminated soils.
- Published
- 2021
34. Risk assessment of hazardous elements in wastewater irrigated soil and cultivated vegetables in Pakistan
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Sardar Khan, Salma Khalid, Zia ur Rahman, Rashid Nazir, Sadia Alam, Abdullah Khan, Alia Naz, Said Muhammad, and Rafiq Ahmad
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education.field_of_study ,Irrigation ,010504 meteorology & atmospheric sciences ,business.industry ,Population ,Contamination ,010502 geochemistry & geophysics ,01 natural sciences ,Hazard quotient ,Toxicology ,Wastewater ,Agriculture ,Bioaccumulation ,Soil water ,General Earth and Planetary Sciences ,Environmental science ,business ,education ,0105 earth and related environmental sciences ,General Environmental Science - Abstract
Wastewater irrigation leads to the deposition of hazardous elements (HE) in irrigated soils which could be accumulated in cultivated vegetables, contaminating the food chain and pose threat to the human population. HE concentrations could be varied in the wastewater-irrigated and background soil and cultivated vegetables with season depending on temperature, humidity, and quantity of irrigation water. For this purpose, soil and vegetable samples were collected in the summer and winter seasons of Peshawar, Pakistan, and analyzed for HE including Cu, Cr, Cd, Co, Zn, Pb, Mn, and Ni. Results revealed that HE contaminations except for Ni in wastewater-irrigated soil and vegetables of both seasons were multifold higher than reference. Between seasons, summer had higher HE contamination in soil and vegetables compared to the winter season. The Cd and Ni concentrations in soil and Pb, Cd, and Cr in vegetables of both seasons exceeded their respective threshold limits set by the Food and Agriculture Organization/World Health Organization. Soil enrichment factors for HE contamination were observed greater than one that could be attributed to wastewater irrigation. Higher values of bioaccumulation factors were found for Cd (1.4), Co (1.8), and Cu (4.0). HE concentrations of vegetables were used for the risk assessment using average daily intake (ADI) and target hazard quotient (THQ). The ADI values of Cd and Pb were observed higher than their respective referenced dose. The THQ values ranged from 0.002–3.86 and 0.02–3.46 for adults and children. Higher THQ values could result in various health problems for the exposed human community.
- Published
- 2020
35. Experimental and theoretical investigation of micellization behavior of sodium dodecyl sulfate with cetyltrimethylammonium bromide in aqueous/urea solution at various temperatures
- Author
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Mohammed Abdullah Khan, Malik Abdul Rub, Shahed Rana, Shamim Mahbub, and Md. Anamul Hoque
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Activity coefficient ,Aqueous solution ,General Chemical Engineering ,Analytical chemistry ,02 engineering and technology ,General Chemistry ,Flory–Huggins solution theory ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Mole fraction ,01 natural sciences ,Micelle ,0104 chemical sciences ,chemistry.chemical_compound ,chemistry ,Bromide ,Sodium dodecyl sulfate ,0210 nano-technology ,Energy (signal processing) - Abstract
Mixed micelle formation behavior of cationic surfactant-cetyltrimethylammonium bromide (CTAB) and anionic surfactant sodium dodecyl sulfate (SDS) in aqueous as well as in urea medium from 303.15 K to 323.15 K at 5 K interval was carried out by conductometric method. The differences between the experimental values of critical micelle concentrations (cmc) and ideal critical micelle concentrations (cmcid) illustrate the interaction between the amphiphiles studied. The values of micellar mole fraction ( $$\text{X}_1^{Rub}$$ (Rubingh), $$\text{X}_1^{M}$$ (Motomura), $$\text{X}_1^{Rod}$$ (Rodenas) and $$\text{X}_1^{id}$$ (ideal) of surfactant CTAB determined by different proposed models and outcome indicate high involvement of CTAB in SDS-CTAB mixed micellization, which enhance by means of the augment of mole fraction of CTAB. The negative value of interaction parameter (β) showed an attractive interaction involving CTAB and SDS. Activity coefficients were less than unity in all case, which also reveals the presence of interaction between CTAB & SDS. The negative $$\Delta{\text{G}}_m^0$$ values imply the spontaneous mixed micellization phenomenon. The attained values of $$\Delta{\text{H}}_m^0$$ were positive at inferior temperature, while negative at superior temperature. The negative $$\Delta{\text{H}}_m^0$$ values in urea (NH2CONH2) medium illustrate exothermic micellization process. The magnitudes of $$\Delta{\text{S}}_m^0$$ were positive in almost all cases. The excess free energy of mixed micelle formation (ΔGex) was found to be negative, which indicates the stability of mixed micelle as compared to the individual’s components micelles.
- Published
- 2018
36. Integrated species–phenon trees: visualizing infraspecific diversity within lineages
- Author
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James G. Ogg, Abdullah Khan Zehady, and Barry G. Fordham
- Subjects
0106 biological sciences ,0301 basic medicine ,Systematics ,Speciation ,Population ,lcsh:Medicine ,Foraminifera ,010603 evolutionary biology ,01 natural sciences ,Article ,Evolution, Molecular ,03 medical and health sciences ,Phylogenetics ,lcsh:Science ,education ,Phylogeny ,education.field_of_study ,Multidisciplinary ,Fossils ,lcsh:R ,Plankton ,030104 developmental biology ,Geography ,Evolutionary biology ,Molecular phylogenetics ,lcsh:Q - Abstract
The unprecedented detail with which contemporary molecular phylogenetics are visualizing infraspecific relationships within living species and species complexes cannot as yet be reliably extended into deep time. Yet paleontological systematics has routinely dealt in (mainly) morphotaxa envisaged in various ways to have been components of past species lineages. Bridging these perspectives can only enrich both. We present a visualization tool that digitally depicts infraspecific diversity within species through deep time. Our integrated species–phenon tree merges ancestor–descendant trees for fossil morphotaxa (phena) into reconstructed phylogenies of lineages (species) by expanding the latter into “species boxes” and placing the phenon trees inside. A key programming strategy to overcome the lack of a simple overall parent–child hierarchy in the integrated tree has been the progressive population of a species–phenon relationship map which then provides the graphical footprint for the overarching species boxes. Our initial case has been limited to planktonic foraminfera via Aze & others’ important macroevolutionary dataset. The tool could potentially be appropriated for other organisms, to detail other kinds of infraspecific granularity within lineages, or more generally to visualize two nested but loosely coupled trees.
- Published
- 2019
37. Synthesis of Magnetite Nanoparticles and Its Application As Electrode Material for the Electrochemical Oxidation of Methanol
- Author
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Muhammad Tariq Shah, Pirah Panah, Kausar Rajar, Muhammad Saqaf Jagirani, Ali Muhammad Mahar, Aamna Balouch, Humaira Khan, and Abdullah Khan
- Subjects
Working electrode ,Materials science ,Nanoparticle ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Electrochemistry ,01 natural sciences ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,Indium tin oxide ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,Electrode ,Materials Chemistry ,Methanol ,Electrical and Electronic Engineering ,Fourier transform infrared spectroscopy ,Cyclic voltammetry ,0210 nano-technology - Abstract
In this study, magnetite (Fe3O4) nanoparticles were synthesized by a simple and facile chemical co-precipitation method at ambient laboratory conditions. The synthesized Fe3O4 nanostructures were characterized for their morphology, size, crystalline structure and component analysis using field emission scanning electron microscopy, Fourier transform infrared spectroscopy, transmission electron microscopy, x-ray diffraction and electron dispersive x-ray spectroscopy. The Fe3O4 nanoparticles showed semi-spherical geometry with an average particle diameter up to 14 nm. The catalytic properties of Fe3O4 nanoparticles were evaluated for electrochemical oxidation of methanol. For this purpose, the magnetite NPs were coated on the surface of an indium tin oxide (ITO) electrode and used as a working electrode in the electrochemical oxidation of methanol. The effect of potential scan rate, the concentration of methanol, the volume of electrolyte and catalyst (Fe3O4 NPs) deposition volume was studied to get high peak current densities for methanol oxidation. The stability and selectivity of the fabricated electrode (Fe3O4/ITO) were also assessed during the electrochemical process. This study revealed that the Fe3O4/ITO electrode was highly stable and selective towards methanol electrochemical oxidation in basic (KOH) media. Bare ITO and Fe3O4 NPs modified glassy (Fe3O4/GCE) electrodes were also tested in the electro-oxidation study of methanol, but their peak current density responses were very low as compared to the Fe3O4/ITO electrode, which showed high electrocatalytic activity towards methanol oxidation under similar conditions. We hope that Fe3O4 nanoparticles (NPs) will be an alternative for methanol oxidation as compared to the expensive noble metals (Pt, Au, and Pd) for energy generation processes.
- Published
- 2018
38. Integrated species–phenon trees: visualizing infraspecific diversity within lineages
- Author
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Zehady, Abdullah Khan, primary, Fordham, Barry G., additional, and Ogg, James G., additional
- Published
- 2019
- Full Text
- View/download PDF
39. A compact broadband stacked medium power amplifier in standard 65 nm CMOS technology
- Author
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Mohsin M. Tarar, Muhammad Abdullah Khan, Muh-Dey Wei, and Renato Negra
- Subjects
Engineering ,Power-added efficiency ,business.industry ,Amplifier ,020208 electrical & electronic engineering ,Electrical engineering ,020206 networking & telecommunications ,Topology (electrical circuits) ,02 engineering and technology ,Input impedance ,Inductor ,Surfaces, Coatings and Films ,CMOS ,Hardware and Architecture ,Signal Processing ,0202 electrical engineering, electronic engineering, information engineering ,Output impedance ,business ,NMOS logic - Abstract
This work presents the design and implementation of a fully integrated and compact broadband medium stacked power amplifier in standard 65 nm bulk CMOS. The amplifier topology utilizes three NMOS stack and three PMOS stack at the output to primarily increase the output impedance along with the output voltage swing. The load impedance is further optimized with a resistive feedback to the input active device which not only results in broadband operation but also helps in avoiding large and lossy broadband output matching network, resulting in a significant area reduction. Further, small interstage peaking inductors are employed to peak the parasitics capacitances that limit the broadband operation. The proposed amplifier works directly into a $$50\Omega $$50Ω load and shows a measured peak saturated output power from 13 to 8.5 dBm and a $$P_{1dB}$$P1dB of 7---4 dBm from 0.3 to 10 GHz. The drain and peak power added efficiency are 6.5 and 4.3 % under 4 V supply with DC power consumption of 160 mW. The measured small signal gain is around 9 dB with a gain ripple of ±1.5 dB till 7 GHz and 5.4 dB at 10 GHz, yielding a fractional bandwidth of 188 %. The measured load-pull ź1 dB, ź2 dB output power contours verify the optimum impedance around $$50\,\Omega $$50Ω. The active chip area is only 0.44 mm2.
- Published
- 2016
40. Analysis and design of class-O RF power amplifiers for wireless communication systems
- Author
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Muhammad Abdullah Khan, Ahmed Farouk Aref, Renato Negra, and Mohsin M. Tarar
- Subjects
Engineering ,Power-added efficiency ,Current-feedback operational amplifier ,business.industry ,Amplifier ,020208 electrical & electronic engineering ,RF power amplifier ,Electrical engineering ,Differential amplifier ,020206 networking & telecommunications ,Common source ,02 engineering and technology ,Surfaces, Coatings and Films ,Hardware and Architecture ,Signal Processing ,Hardware_INTEGRATEDCIRCUITS ,0202 electrical engineering, electronic engineering, information engineering ,Electronic engineering ,Linear amplifier ,business ,Direct-coupled amplifier - Abstract
In this paper, we present analysis, design and show experimental results of a new type of CMOS based power amplifier (PA) known as class-O Aref et al. (ISSCC Digest of Technical Papers, 2015). Modern CMOS based PAs design is constrained by three fundamental trade-offs, i.e. linearity, efficiency and reliability. More precisely, for a standalone PA, unless advanced and expensive solutions are employed, no such PA architecture exists which is able to meet aforementioned design trade-offs. Theoretical insight is needed to understand the origin of performance trade-offs and the possible solutions to counter them. Class-O is a novel out-of-the-box solution to meet these tough challenges. Our prototype amplifier is a highly linear low-band 706 MHz 4G long term evolution (LTE) compatible class-O RF power amplifier in 130 nm CMOS technology for handheld wireless applications. The class-O architecture uses two sub-amplifiers working together as one grand PA. These two sub-amplifiers are common-source (CS) and common-drain (CD) amplifiers working in parallel feeding a common load with high linearity without the need for digital predistortion (DPD). The prototype chip is measured and characterized with continuous wave (CW), modulated signal and reliability measurements. With CW measurements, 1-dB compression point (P$$_{1\,{\mathrm{dB}}}$$1dB) of 30.6 dBm and peak power added efficiency (PAE) of 45.2 $$\%$$% is achieved. For the modulated signal measurements, the amplifier is tested with 16-QAM 20 MHz LTE signal with peak-to-average-power ratio of 6.54 dB. The amplifier meets the stringent LTE specs with an adjacent channel power ratio (ACPR) less than ź30 dBc for both EUTRA and UTRA1 with average output power of 27 dBm and PAE above 20 $$\%$$%. Owing to the voltage following between gate source junctions in the common-drain amplifier in addition to cascode structure of common source amplifier, the stress is significantly reduced at the transistor terminals. The reliability is demonstrated by operating the amplifier in nominal and worst voltage-standing-wave-ratio (VSWR) conditions.
- Published
- 2016
41. Socio-political and ecological stresses on traditional pastoral systems: A review
- Author
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Muhammad, Khurshid, primary, Mohammad, Nafees, additional, Abdullah, Khan, additional, Mehmet, Somuncu, additional, Ashfaq, Ahmad Khan, additional, and Wajid, Rashid, additional
- Published
- 2019
- Full Text
- View/download PDF
42. Potentially toxic elements concentrations and human health risk assessment of food crops in Bajaur Agency, Pakistan
- Author
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Alia Naz, Abdullah Khan, Zia Ullah, Umar Saddique, Wisal Shah, and Said Muhammad
- Subjects
0211 other engineering and technologies ,Brassica ,Soil Science ,chemistry.chemical_element ,02 engineering and technology ,Zinc ,010501 environmental sciences ,01 natural sciences ,law.invention ,Crop ,Toxicology ,law ,Environmental Chemistry ,0105 earth and related environmental sciences ,Earth-Surface Processes ,Water Science and Technology ,021110 strategic, defence & security studies ,Global and Planetary Change ,Cadmium ,biology ,business.industry ,fungi ,food and beverages ,Geology ,biology.organism_classification ,Pollution ,Hazard quotient ,chemistry ,Agronomy ,Agriculture ,Atomic absorption spectroscopy ,business ,Risk assessment - Abstract
This study investigates the potentially toxic elements (PTEs) concentrations in various food crops along the Bajaur Agency. For this purpose, food crop samples were collected and analyzed for PTEs including cadmium (Cd), nickel (Ni), chromium (Cr), copper (Cu), cobalt (Co), zinc (Zn) and lead (Pb) by atomic absorption spectrometer (PerkinElmer, AAS-PEA-700). Among the food crops, Spinacia oleracea L. showed the highest concentrations for Ni, Cr, Cu, Co and Pb, Brassica juncea (L.) Czern. for Cd, and Zea mays L. for Pb. The concentrations of the Cd, Cr and Ni in food crops have surpassed the safe limits set by Food and Agriculture Organization/World Health Organization. Determined PTEs concentrations in food crops were evaluated for the risk assessment through single and collectively PTEs and food crop using the daily intake of metals (DIM) and hazard quotient (HQ). Results revealed that through food crops intake the highest values of DIM and HQ were observed for Zn and Cd, respectively. Children showed the highest HQ values, compared to adults for Triticum aestivum L. consumption. High HQ values can cause hazardous health problem in exposed populations; therefore, this study recommends regular monitoring of PTEs concentrations in food crops.
- Published
- 2017
43. Petrofacies, provenance, and paleocurrent analysis of Pachmarhi sandstone (Early Triassic), Satpura basin, Central India
- Author
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Sarwar Rais, Anis, and Abdullah Khan
- Subjects
geography ,Provenance ,geography.geographical_feature_category ,Early Triassic ,Craton ,Gondwana ,Paleontology ,Precambrian ,Basement (geology) ,General Earth and Planetary Sciences ,Siliciclastic ,Paleocurrent ,Geology ,General Environmental Science - Abstract
The Satpura Gondwana basin hosts a ∼5 km thick siliciclastic succession that unconformably overlies the Precambrian basement. The Gondwana sequence in this basin starts from Early Permian (Talchir Formation) to Lower Cretaceous (Jabalpur Formation). The aim of this study is to (1) identify the source rock (provenance) for Early Triassic Pachmarhi sediments in the Satpura Gondwana succession and (2) to understand the relative role of tectonics and climate in determining the sandstone composition. These sandstones are medium to coarse-grained, moderately to moderately well sorted, subangular to subrounded, of moderate sphericity, and composed of several varieties of quartz, feldspar, rock fragments, and micas. Petrographically, the Pachmarhi sandstones are mostly quartzarenite and subarkose. The petrofacies in Qt–F–L and Qm–F–Lt triangular diagrams show that the bulk of the Pachmarhi was derived from continental (cratonic) source, especially from craton interior. Petrofacies, together with paleocurrent data, suggest that Pachmarhi Formation was deposited by a network of braided river system, which flowed dominantly from southeast to northwest. The study suggests that the sediments were mostly derived from Precambrian granites, gneiss, and metasedimentary basement rocks straddling the southern margin of the basin. Paleocurrent data also corroborates this contention.
- Published
- 2013
44. Study of ion–solvent interactions and activation energy of LiBr in DMSO, H2O and DMSO–H2O mixtures at various temperatures
- Author
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Fahim Uddin, Shaheen Durrani, Abdullah Khan, and Talat Zamir
- Subjects
Ammonium bromide ,Lithium bromide ,General Chemical Engineering ,Inorganic chemistry ,General Engineering ,General Physics and Astronomy ,Ionic bonding ,Activation energy ,Electrolyte ,Alkali metal ,Mole fraction ,Solvent ,chemistry.chemical_compound ,chemistry ,General Materials Science - Abstract
The Jones–Dole B coefficients of the electrolyte Lithium bromide (LiBr), reference salts tetra butyl ammonium tetra phenyl borate (BU4NBPh4), tetra butyl ammonium bromide (BU4NBr), and potassium chloride (KCl) in dimethylsulfoxide (DMSO), water, and DMSO–water mixtures were obtained at different temperatures range from 25 to 45 °C For this, the relative viscosities were measured for Lithium bromide (LiBr) and reference salts in DMSO, water, and DMSO–water mixtures at above-mentioned temperatures. The B coefficients of these electrolytes were behaved as structure makers in DMSO, while in H2O and DMSO–H2O mixtures, the B-coefficient values were less positive showing the weak structure-making effect. Ionic viscosity B coefficients allow us to assess the behavior of ions in the solvent mixtures. In this study it was observed that all the values of ionic B coefficient of (Li+) were positive and small showing the weak structure-making effects. It was also observed that Br− ions maintain negative B coefficient values in all DMSO–H2O mixtures, except in 60% DMSO mole fraction. From this it can be concluded that Br− ion behaved as a structure breaker in water and in all DMSO–H2O mixtures except in 60% DMSO mole fraction mixtures. The low B ± values of alkali metal ions and Br− ions in water are due to the breakdown of the tetrahedral structural of water and the formation of strongly structured solvated ion. It is also observed that the values of the energy of activation of the flow for LiBr are greater in DMSO–water mixtures and in pure water than in DMSO. This may be due the presence of a network of hydrogen bonds which cause the hindrance in the flow of the solution of LiBr in DMSO–water mixtures and in pure water than in DMSO.
- Published
- 2007
45. M.R. JOELSON, An International Antitrust Primer: A Guide to the Operation of the United States, European Union and Other Key Competition Laws in the Global Economy, 2nd edn., Kluwer Law International, The Hague 2001, xix + 496 pp., 180US$165UK114. ISBN 90-411-9854-7
- Author
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R.A. Abdullah Khan
- Subjects
Competition (economics) ,business.industry ,Political science ,European integration ,Key (cryptography) ,media_common.cataloged_instance ,International trade ,European union ,business ,Law ,media_common - Published
- 2003
46. M.R. JOELSON, An International Antitrust Primer: A Guide to the Operation of the United States, European Union and Other Key Competition Laws in the Global Economy, 2nd edn., Kluwer Law International, The Hague 2001, xix + 496 pp., 180US$165UK114. ISBN 90-411-9854-7.
- Author
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Abdullah Khan, R.A., primary
- Published
- 2003
- Full Text
- View/download PDF
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