Ahmad Mukhtar - Academia.edu (original) (raw)

Papers by Ahmad Mukhtar

Current Topics in Nutraceutical Research, Sep 5, 2018

This study investigates the effect of enzyme formulations (Zympex-014, Kemzyme dry-plus and Natuz... more This study investigates the effect of enzyme formulations (Zympex-014, Kemzyme dry-plus and Natuzyme) on recovery of phenolics from Peganum hermala (harmal) leaves, under optimized conditions using response surface methodology. As compared to the other enzyme complexes, the yield (34 g/100g) obtained through Zympex-014-assisted extraction was higher under optimized conditions such as time (75 min), temperature (70°C), pH (6.5) and enzyme concentration (5 g/100 g) using central composite design (CCD). Effectiveness of Zympex-014 towards hydrolysis of P. hermala leaves cell wall was examined by analyzing the control and enzyme-treated leave residues using scanning electron microscope (SEM). GC/MS characterization authenticated the presence of quercetin (1.44), gallic acid (0.23), caffeic acid (0.04), cinnamic acid (0.05), m-coumaric acid (0.23) and p-coumaric acid (0.37 μg/g) as the potent phenolics in Zympex-014 based extract. It can be concluded from the findings of the current work that pre-treatment of P. hermala leaves with Zympex-014 significantly enhanced the recovery of phenolics that supports its potential uses in the nutra-pharamaceutical industry.

Social Science Research Network, Jul 15, 2020

Sustainable growth in Agriculture is not only a national priority in all countries but a global e... more Sustainable growth in Agriculture is not only a national priority in all countries but a global endeavor as well, particularly to achieve the SDG-2. There are, however, some perceptions that rules of the World Trade Organization’s (WTO) agreements may hinder policy space in this regard. This information note attempts to outline the relevant rules on domestic support (subsidies) in the WTO Agreement on Agriculture (AoA) and highlights the available policy space with Member Countries to support the sustainable agriculture. It shows that the provisions under Development Box and Green Box provide, essentially, an unlimited allowance for subsidizing agriculture subject to criteria defined therein.

Human Vaccines & Immunotherapeutics, 2021

Health care workers play an important role in supporting childhood vaccination as they are the mo... more Health care workers play an important role in supporting childhood vaccination as they are the most trusted source of vaccine-related information for parents. However, there is limited validated tools to measure their knowledge and attitude on childhood vaccination. This study aims to develop and validate knowledge and attitude regarding childhood vaccination (KACV) questionnaire among healthcare workers. The questionnaire was developed based on literature reviews and underwent a sequential validation process, including content, face validity and exploratory factor analysis. However, the attitude section is unidimensional and has undergone reliability analysis only. The preliminary knowledge questionnaire contains 33 items and the attitude questionnaire consists of 17 items. The preliminary KACV showed a high item Content Validity Index and Face Validity Index. The final questionnaire consists of 10 items for knowledge and 15 items for attitude. The Cronbach alpha for the knowledge and attitude section were 0.896 and 0.861, respectively. KACV is a valid and reliable tool to measure healthcare workers' knowledge and attitude on childhood vaccination.

Nanomaterials: Synthesis, Characterization, Hazards and Safety, 2021

Abstract Nanotechnology is very ancient technology and its usage was first recorded in the 9th ce... more Abstract Nanotechnology is very ancient technology and its usage was first recorded in the 9th century. There are many cases of ancient objects utilizing nanocomposites; impressive examples are glass that alters color due to reflection of light and steel swords with incredible strength, crushing resistance, and extraordinarily sharp edges. Nanoparticles have a wide surface area and many particles per unit mass compared with microparticles. Initially, observations of nanoscale particles were gold-related. There are different synthetic methods for nanoparticle synthesis such as bottom-up, hydro/solvothermal, and top-down. The bottom-up methods include organic ligand-assisted growth, mediated synthesis of small molecules and ions, 2D template-confined growth, and seeded growth. The hydro methods include crystal phase transformation, biological synthesis, and nanoparticle assembly. The top-down methods include the mechanical compression method, exfoliation, and nanolithography.

SN Applied Sciences, 2020

Usually, nitrogen and argon adsorption-desorption isotherms are used at their respective boiling ... more Usually, nitrogen and argon adsorption-desorption isotherms are used at their respective boiling points for the determination of specific surface area via the BET theory of microporous materials. However, for ultra-micropores, where nitrogen and argon cannot access at cryogenic temperatures, the CO 2 adsorption-desorption isotherms have been considered as alternative options for the determination of specific surface area by extending BET theory, but the surface area determined by using CO 2 adsorption-desorption isotherms is not significant due to strong CO 2-CO 2 interactions. In this study, the microporous covalent organic polymers are subjected to nitrogen and CO 2 adsorption-desorption isotherms and the results showed that a clear linear region is available in isotherms, which confirms the presence of ultra-micropores. The surface area determined by the CO 2 adsorption-desorption isotherms is higher than the surface area determined by N 2 adsorption-desorption isotherms. These results indicate that the microporous covalent organic polymers contain ultra-micropores where only CO 2 can reach, while nitrogen and argon cannot access at cryogenic conditions because their kinetic diameter is larger than CO 2 .

Chemosphere, 2021

The restoration of mechanical properties is desired for creating the self-healing coatings with n... more The restoration of mechanical properties is desired for creating the self-healing coatings with no corrosion capabilities. The encapsulation of epoxy resins is limited by various factors in urea and melamine formaldehyde microcapsules. An improved method was developed, where epoxy resin was encapsulated by individual wrapping of poly(melamine-formaldehyde) and poly(urea-formaldehyde) shell around emulsified epoxy droplets via oil-in-water emulsion polymerization method. The synthesized materials were characterized analytically. The curing of the epoxy was achieved by adding the [Ni/Co(2-MI)6].2NO3 as a latent hardener and iron acetylacetonate [Fe(acac)3] as a latent accelerator. Isothermal and non-isothermal differential scanning calorimetric analysis revealed lower curing temperature (Tonset = 116 °C) and lower activation energies (Ea ≈ 69-75 kJ/mol). The addition of microcapsules and complexes did not adversely alter the flexural strength and flexural modulus of the epoxy coatings. The adhesion strength of neat coating decreased from 6310.8 ± 31 to 4720.9 ± 60 kPa and percent healing increased from 50.83 to 67.45% in the presence of acetylacetonate complex at 10 wt% of microcapsules.

Chemosphere, 2022

Hydrogel is the most emblematic soft material which possesses significantly tunable and programma... more Hydrogel is the most emblematic soft material which possesses significantly tunable and programmable characteristics. Polymer hydrogels possess significant advantages including, biocompatible, simple, reliable and low cost. Therefore, research on the development of hydrogel for biomedical applications has been grown intensely. However, hydrogel development is challenging and required significant effort before the application at an industrial scale. Therefore, the current work focused on evaluating recent trends and issues with hydrogel development for biomedical applications. In addition, the hydrogel's development methodology, physicochemical properties, and biomedical applications are evaluated and benchmarked against the reported literature. Later, biomedical applications of the nano-cellulose-based hydrogel are considered and critically discussed. Based on a detailed review, it has been found that the surface energy, intermolecular interactions, and interactions of hydrogel adhesion forces are major challenges that contribute to the development of hydrogel. In addition, compared to other hydrogels, nanocellulose hydrogels demonstrated higher potential for drug delivery, 3D cell culture, diagnostics, tissue engineering, tissue therapies and gene therapies. Overall, nanocellulose hydrogel has the potential for commercialization for different biomedical applications.

NUST Journal of Engineering Sciences, 2019

Global survival and human comfort in now a day strongly depend upon energy and environment. In th... more Global survival and human comfort in now a day strongly depend upon energy and environment. In this research generalized thermodynamic model equations were subjected to 4MW rice husk fired thermal power plant in Pakistan for theoretical investigations on work lost and entropy generation to check the plant thermal performance and irreversibility’s and concluded that the entropy generation and work lost is highest in Furnace/Boiler that is 3487.12352 KWK-1 and 1039.685 ×103 respectively. The work lost in Furnace/Boiler is about 32.4641% while the overall efficiency of the power plant is 59.8917%.

$Research paper thumbnail of Experimental investigation and modeling of the density, refractive index, and dynamic viscosity of 1-Propyronitrile-3-Butylimidazolium Dicyanamide$

Journal of Molecular Liquids, 2020

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Microporous and Mesoporous Materials, 2019

Chemical Engineering & Technology, 2019

Membrane technology has emerged as a leading tool worldwide for effective CO2 separation because ... more Membrane technology has emerged as a leading tool worldwide for effective CO2 separation because of its well‐known advantages, including high surface area, compact design, ease of maintenance, environmentally friendly nature, and cost‐effectiveness. Polymeric and inorganic membranes are generally utilized for the separation of gas mixtures. The mixed‐matrix membrane (MMM) utilizes the advantages of both polymeric and inorganic membranes to surpass the trade‐off limits. The high permeability and selectivity of MMMs by incorporating different types of fillers exhibit the best performance for CO2 separation from natural gas and other flue gases. The recent progress made in the field of MMMs having different types of fillers is emphasized. Specifically, CO2/CH4 and CO2/N2 separation from various types of MMMs are comprehensively reviewed that are closely relevant to natural gas purification and compositional flue gas treatment

Climatic resilience of wheat is its capacity to absorb disorder, maintain, self-organization whil... more Climatic resilience of wheat is its capacity to absorb disorder, maintain, self-organization while retaining the same basic structure and ways of functioning, adaptating to stress and change.The present studies were conducted with the objectives (a) to understand wheat crop biodynamism and its relation with yield under variable climatic conditions of Pothwar, (b) to parameterize and evaluate the APSIM-wheat module under variable local environmental conditions (c) to enhance understanding about the resilience of wheat under rainfed conditions using APSIM.Field trials on wheat were performed during two wheat growing environments from 2008 to 2010 at high (Islamabad), medium (Chakwal) and low (Talagang) rainfall zones of Pothwar.A Randomized complete block design was used and three wheat genotypes (Chakwal-50, Wafaq-2001 and GA-2002) were replicated four times among five planting windows denoted as PW's. The PW‘s as management‘s starts from October and ended at the start of December.These five planting windows were denoted as PW1 (Sowing between 10-20 October), PW2 (Sowing between 21-31 October), PW3 (Sowing between 1-10 November), PW4 (Sowing between 11-20 November) and PW5 (Sowing between 01-10 December). Daily rainfall data (1961-2010) were obtained from the Pakistan Meteorological Department. Soil water dynamics recorded layer wise at pre-sowing, three leaf, tillering anthesis and maturity stages of crop showed significant variability at different locations among PW‘s and environments.Significant differences were observed in the pattern of emergence rate index (ERI), growth, drymatter accumulation, yield and grain quality of wheat crop at three l ocations among PW‘s and during two environments (2008-09 and 2009-10).The number of days for phenological development of crop (Z13, Z20, Z60 and Z92) remained statistically higher at Islamabad during 2008-09 as compared to other locations and second environment.Dry matter accumulation at three leaf and anthesis stage remained significantly different during two environments, three locations and planting windows.However, decline in drymatter at Talagang, late sowing and during 2009-10 was due to prevailing stresses in the form of moisture and temperature.Thetrend of growth dynamics (crop growth rate (CGR) and net assimilation rate (NAR)) remained greater during 2008-09 for PW2 at Islamabad while lowest at Talagang and during 2009-10.The CGR and NAR reduction was recorded for all genotypes from Islamabad to Talagang moving from PW1 to PW5. Physiological parameters like stomatal conductance (gs), Stomatal resistance (rs), Net Photosynthetic rate (An), Transpiration rate (E) and Intercellular CO2 (Ci) were significantly affected due to treatments (environments, locations, PW‘s and genotypes).The maximum stomatal conductance recorded during 2008-09 (0.639 mole m-2 sec-1) while minimum noted during 2009-10 (0.498 mole m-2 sec-1).However, stomatal resistance remained inverse to conductance among treatments. Similarly, significant variability in SPAD chlorophyll contents and proline concentration recorded at anthesis among treatments. Grain yield reduced for all genotypes with change in planting windows during two environments at three variable locations.Quantification of this yield to environmental variables depicted reduction (65 kg/ha/day) across the genotypes and environments. Similar trend was observed for other yield components.The Agricultural Production System Simulator (APSIM) was evaluated and parameterized as a bioinformatics tool using wheat crop, soil and climatic data of three locations of Pothwar.The optimization and modification of various genotype coefficients lead to goodness of fit between simulated and observed data regarding the occurrence of anthesis and maturity by accurately regulating the phasic development of the genotypes used in this study.This improvement in the models ability also improved the simulation capabilities of the model regarding days after sowing, leaf area index (LAI), drymatter accumulation, yield, harvest index (HI) and total soil water extraction across treatments.The validated crop simulation model was used as decision support tool for selecting optimum planting window and genotypes at different locations during variable environments.The simulation analysis regarding partioning of yield across PW‘s at different locations among genotypes showed that sowing after PW3 was more vulnerable to climate fluctuations governed by SOI phases in July.The long term APSIM analysis depicted that increase or decrease in wheat yield is linked with rainfall variability governed by Southern Oscillation Index (SOI) phases in July.The analysis using probabilistic approach based on long term rainfall variability revealed 44, 40 and 35 % possibility of exceeding median rain for Islamabad, Chakwal and Talagang when SOI phase in July is near zero, whereas possibility of exceeding 35, 34 and 33% possibility of exceeding median rain at Islamabad,…

The world is facing declining liquid fuel reserves at a time when energy demand is exploding. Alt... more The world is facing declining liquid fuel reserves at a time when energy demand is exploding. Alternative fuel is currently an important issue all over the world due to efforts on reducing the global warming which is contributed by the combustion of petroleum or petrol diesel. In order to achieve a secure and stable energy supply that does not cause environmental damage, renewable energy sources must be explored and promising technologies must be developed. In this study one of the renewable energy technology known and Fischer-Tropsch Synthesis is considered and a design methodology for the Fischer-Tropsch Reactor for the production of Green Diesel from Coal Syngas is presented.

Hydrocarbon and Heavy Oil-Water Separators are fall in major mass transfer operations and a key c... more Hydrocarbon and Heavy Oil-Water Separators are fall in major mass transfer operations and a key component of chemical process industries. They have wide applications in purification and especially in water treatment processes. Many technical papers have been written on the Hydrocarbon and Heavy Oil-Water separator design and vast amounts of information are also available in corporate process engineering design guidelines. The purpose of this work is to provide a comprehensive current design status of Hydrocarbon and Heavy Oil-Water Separators. This type of Hydrocarbon and Heavy Oil-Water Separators which is presented in this work is usually design and used for the separation of hydrocarbons produced during Fischer-Tropsch Synthesis of green diesel from synthesis gas.

Academic Journal of Interdisciplinary Studies, 2013

Social Studies Education as a field of study instills in students the knowledge, skills, attitude... more Social Studies Education as a field of study instills in students the knowledge, skills, attitudes and actions that are considered important in the relationship and interaction of man and those around him on one han, and the entire environment (Ogun Bameru, 2006). The paper examines social studies education in the context of Nigeria's philosophical goals as a nation, the objectives of social studies education and how they can be used to achieve national goals and development and proffers some suggestions which include public enlightenment and teaching basic tenets of social interaction among others.

Bioresource Technology, 2009

The ability of Ca-alginate immobilized Trichoderma harzianum has been explored for removal and re... more The ability of Ca-alginate immobilized Trichoderma harzianum has been explored for removal and recovery of uranium from aqueous streams. Ca-alginate as polymeric support was selected after screening different matrices. Immobilization of Trichoderma harzianum to Ca-alginate improved the stability as well as uranium biosorption capacity of biosorbent at 28+/-2 degrees C and 200 rpm. The suitability of packed bed column operations was illustrated by obtaining break through curves at different bed heights, flow rates and inlet uranium concentrations. The adsorption column containing 1.5 g dry weight of immobilized material has purified 8.5L of bacterial leach liquor (58 mg/LU) before break through occurred and the biosorbent became saturated after 25 L of influent. Sorbed uranium was recovered in 200 ml of 0.1N HCl resulting in 98.1-99.3% elution by 0.1N HCl, which regenerated the biosorbent facilitating the sorption-desorption cycles for better economic feasibility without any significant alteration in sorption capacity/elution efficiency.