Other affiliations: Pakistan Council of Scientific and Industrial Research, American University of Sharjah, Petronas ...read more
Bio: Muhammad Irfan is an academic researcher from Najran University. The author has contributed to research in topics: Medicine & Computer science. The author has an hindex of 36, co-authored 646 publications receiving 6333 citations. Previous affiliations of Muhammad Irfan include Pakistan Council of Scientific and Industrial Research & American University of Sharjah.
Papers published on a yearly basis
TL;DR: In this review article recent developments in continuous flow heterogeneous catalytic hydrogenation reactions using molecular hydrogen are summarized.
Abstract: Microreactor technology and continuous flow processing in general are key features in making organic synthesis both more economical and environmentally friendly. Heterogeneous catalytic hydrogenation reactions under continuous flow conditions offer significant benefits compared to batch processes which are related to the unique gas-liquid-solid triphasic reaction conditions present in these transformations. In this review article recent developments in continuous flow heterogeneous catalytic hydrogenation reactions using molecular hydrogen are summarized. Available flow hydrogenation techniques, reactors, commonly used catalysts and examples of synthetic applications with an emphasis on laboratory-scale flow hydrogenation reactions are presented.
TL;DR: In this article, the authors investigated the performance of pin-fin configurations with and without phase change materials (PCMs) for heat transfer in electronic integrated circuits and found that triangular pin-fins are the most effective configuration for heat-transfer.
Abstract: This study implies experimental investigation for optimization of heat transfer in electronic integrated circuits using close packed phase change materials (PCMs) filled pin-fin heat sinks. The aim of this study is to find the most efficient pin-fin configuration filled with optimum PCM to extend the operating range of electronic circuits. The experimental methodology is based upon variation of pin-fin configurations in rectangular, round and triangular cross-sections. Each configuration is allowed a pin-fin volumetric percentage of 9%. For analysis using PCM a volume fraction of 90% is maintained and six PCMs with different thermo-physical properties (varying melting temperatures, latent heats and heat capacities) are selected. These include paraffin wax, RT-54, RT-44, RT-35HC, SP-31 and n-eicosane. Moreover, the power levels mimicking heat input range between 5 W and 8 W. The resulting information is analyzed for the performance of a heat sink with and without PCM. Besides that, PCM ascendency is manipulated in terms of operational time, enhancement ratios, Stefan number and storage ratio. The outcomes suggest that triangular pin-fins are found to be the most effective pin-fin configuration for heat transfer both with and without PCM.
TL;DR: The purified cellulase was compatible with four local detergent brands with up to 20 days of shelf life at room temperature suggesting its potential as a detergent additive for improved washing therefore, it is concluded that it may be potentially useful for industrial purposes especially for detergent and laundry industry.
Abstract: This paper reports the purification and characterization of kinetic parameters of cellulase produced from Trichoderma viride under still culture solid state fermentation technique using cheap and an easily available agricultural waste material, wheat straw as growth supported substrate. Trichoderma viride was cultured in fermentation medium of wheat straw under some previously optimized growth conditions and maximum activity of 398±2.43U/mL obtained after stipulated fermentation time period. Cellulase was purified 2.33 fold with specific activity of 105U/mg in comparison to crude enzyme extract using ammonium sulfate precipitation, dialysis and Sephadex-G-100 column chromatography. The enzyme was shown to have a relative low molecular weight of 58kDa by sodium dodecyl sulphate poly-acrylamide gel electrophoresis. The purified enzyme displayed 6.5 and 55oC as an optimum pH and temperature respectively. Using carboxymethyl cellulose as substrate, the enzyme showed maximum activity (Vmax) of 148U/mL with its corresponding KM value of 68uM. Among activators/inhibitors SDS, EDTA, and Hg2+ showed inhibitory effect on purified cellulase whereas, the enzyme activated by Co2+ and Mn2+ at a concentration of 1mM. The purified cellulase was compatible with four local detergent brands with up to 20 days of shelf life at room temperature suggesting its potential as a detergent additive for improved washing therefore, it is concluded that it may be potentially useful for industrial purposes especially for detergent and laundry industry.
TL;DR: In this paper, a review of the research and development in the field of encapsulation using hyperbranched polymers is presented, based on a summary of the most relevant R&D results and encapsulation technologies.
Abstract: Dendritic macromolecules, such as hyperbranched polymers are increasingly being studied in the context of encapsulation. The intensive research on encapsulation using hyperbranched polymers is motivated by factors such as a cost-effective polymer synthesis and a customizable property profile. Hence, in the past few years, hyperbranched polymers have been employed as carriers for several guest molecules such as dyes, pharmaceuticals, cosmetics, catalysts, and aromatic hydrocarbons. However, hyperbranched polymers compete not only with perfectly structured dendrimers but also with conventional carrier molecules in terms of price and performance criteria such as processability, loading capacity, delivery efficiency and/or reduction of toxic side effects. This article aims at reviewing the research and development (R&D) in the field of encapsulation using hyperbranched polymers. Based on a summary of the most relevant R&D results and encapsulation technologies in this area, progress and challenges are discuss...
TL;DR: Results indicated that favorable fermentation conditions and the selection of a suitable growth medium played a key role in the production of cellulase from newly isolated Cellulomonas sp.
Abstract: Objective: The aim of the present study is to demonstrate the isolation, identification and screening of bacteria with high cellulase activity from soil samples. Materials and Methods: Cellulose degrading bacteria were isolated from soil sample using serial dilution and pour plate method. Bacteria were further identified by morphological and biochemical tests and subjected to cellulase production in 250 ml Erlenmayer flask using potato waste medium for 48h of fermentation period at 35oC with agitation speed of 140rpm. Results: Seven different bacterial strains were isolated and screened for cellulase production in submerged fermentation process. Among these seven tested bacterial strains; ASN2 showed maximum yield for cellulase production. This strain was further characterized by biochemical and morphological tests and identified as Cellulomonas sp. ASN2. Supplementation of glucose, peptone and cysteine to the fermentation medium are favored enzyme secretion. The optimum pH and temperature for the activity of crude enzyme was 7.5 and 60oC, respectively. Metal profile of the enzyme indicated that Co2+ and Mn2+ are the strong stimulators while Hg 2+ and Fe 2+ inhibited the activity of cellulase from cellulolytic bacterial strain, Cellulomonas sp.ASN2. Conclusion: Results indicated that favorable fermentation conditions and the selection of a suitable growth medium played a key role in the production of cellulase from newly isolated Cellulomonas sp. ASN2. Due to its particular characteristics this enzyme will be used in saccharification process for bioethanol production from plant biomasses.
TL;DR: There is, I think, something ethereal about i —the square root of minus one, which seems an odd beast at that time—an intruder hovering on the edge of reality.
Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …
TL;DR: In this paper, the authors summarized the simultaneous transmission of several independent spatial channels of light along optical fibres to expand the data-carrying capacity of optical communications, and showed that the results achieved in both multicore and multimode optical fibers are documented.
Abstract: This Review summarizes the simultaneous transmission of several independent spatial channels of light along optical fibres to expand the data-carrying capacity of optical communications. Recent results achieved in both multicore and multimode optical fibres are documented.
TL;DR: This study reviews several of the most commonly used inductive teaching methods, including inquiry learning, problem-based learning, project-basedLearning, case-based teaching, discovery learning, and just-in-time teaching, and defines each method, highlights commonalities and specific differences, and reviews research on the effectiveness.
Abstract: Traditional engineering instruction is deductive, beginning with theories and progressing to the applications of those theories Alternative teaching approaches are more inductive Topics are introduced by presenting specific observations, case studies or problems, and theories are taught or the students are helped to discover them only after the need to know them has been established This study reviews several of the most commonly used inductive teaching methods, including inquiry learning, problem-based learning, project-based learning, case-based teaching, discovery learning, and just-in-time teaching The paper defines each method, highlights commonalities and specific differences, and reviews research on the effectiveness of the methods While the strength of the evidence varies from one method to another, inductive methods are consistently found to be at least equal to, and in general more effective than, traditional deductive methods for achieving a broad range of learning outcomes