Theoretical and experimental investigations of Co-Cu bimetallic alloys-incorporated carbon nanowires as an efficient bi-functional electrocatalyst for water splitting

Zafar Khan Ghouria,Ahmed Badreldin,Khaled Elsaid,Dharmesh Kumar,Karim Youssef,Ahmed Abdel-Wahab 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.96 No.-

Application of noble metal-free electrocatalysts for oxygen evolution reaction (OER) and hydrogenevolution reaction (HER) during electrocatalytic water splitting is crucial for clean energy conversion andhas drawn extensive attention. However, the development of highly active and low cost electrocatalysts isa considerable challenge. Herein, Co-Cu alloy nanoparticles-incorporated carbon nanowires electrocatalystwas synthesized and evaluated for both OER and HER. The nanomaterials were fabricated byfacile electrospinning of sol-gel composed of cobalt acetate, copper acetate, and poly(vinyl alcohol)followed by calcination in an inert environment. Adjusting the composition of the metallic counterpartwas found to significantly enhance electrochemical properties of the catalyst. Furthermore, the uniquenanowire morphology and structural properties of incorporated Co-Cu alloy, the (Co0.95Cu0.05@CNWs)composition exhibits good electrocatalytic performance for both OER and HER in the alkaline medium. Physicochemical characterizations using X-ray diffraction, X-ray photoelectron spectroscope, scanningelectron microscopy, and transmission electron microscopy have confirmed the formation of alloystructure and nanowire morphology. The optimum composition (Co0.95Cu0.05@CNWs) requires smalloverpotential, ɳ10 of285 mV for oxygen evolution reaction (OER) and160 mV for hydrogen evolutionreaction (HER) with the corresponding Tafel slope of 92 mV dec 1 and 172 mV dec 1 versus the reversiblehydrogen electrode, respectively. In addition, only negligible loss in activity was observed after 1000cycles and prodeces cell voltage of 1.58 V at current of 10 mA/cm2 and 1.72 V at current density of 50 mA/cm2 in two electrode system. Density Functional Theory (DFT) calculations were employed to verifyexperimental results. Electronic density of states (DOS) results reveal an increase in electronic states nearthe Fermi level upon Co-Cu heterojunctioning with CNWs. This is indicative of improved catalytic activityand more favorable binding energies of HER and OER intermediates. Reaction coordinate diagrams forHER and OER were developed, which aided in identifying thermodynamically limiting steps. This workmay provide a feasible approach for incorporating other transition metals to design low-cost and highperformancebifunctional electrocatalysts for overall water splitting.

Use of abdominal compression device in colonoscopy: a systematic review and meta-analysis

Yousaf Zafar,Ahmed Mustafa Rashid,Syed Sarmad Javaid,Ahmed Kamal Siddiqi,Adnan Zafar,Arsalan Zafar Iqbal,Jagpal Singh Klair,Rajesh Krishnamoorthi 대한소화기내시경학회 2023 Clinical Endoscopy Vol.56 No.4

Background/Aims: Colonoscopy for screening is associated with unpleasant experiences for patients, and abdominal compression devices have been developed to minimize these problems. However, there is a paucity of data supporting the therapeutic benefits of this strategy. This study examined the effects of using an abdominal compression device during colonoscopy on the cecal intubation time (CIT), abdominal compression, patient comfort, and postural changes. Methods: We searched PubMed and Scopus (from inception to November 2021) for randomized controlled trials that assessed the effects of an abdominal compression device during colonoscopy on CIT, abdominal compression, patient comfort, and postural change. A random-effects meta-analysis was performed. Weighted mean differences (WMDs) and Mantel-Haenszel odds ratios (ORs) were calculated. Results: Our pooled analysis of seven randomized controlled trials revealed that abdominal compression devices significantly reduced CIT (WMD, –0.76 [–1.49 to –0.03] minutes; p=0.04), abdominal compression (OR, 0.52; 95% confidence interval [CI], 0.28–0.94; p=0.03), and postural changes (OR, 0.46; 95% CI, 0.27–0.78; p=0.004) during colonoscopy. However, our results did not show a significant change in patient comfort (WMD, –0.48; 95% CI, –1.05 to 0.08; p=0.09) when using an abdominal compression device. Conclusions: Our findings demonstrate that employing an abdominal compression device may reduce CIT, abdominal compression, and postural change but have no impact on patient comfort.

A Scalable Data Integrity Mechanism Based on Provable Data Possession and JARs

( Faheem Zafar ),( Abid Khan ),( Mansoor Ahmed ),( Majid Iqbal Khan ),( Farhana Jabeen ),( Zara Hamid ),( Naveed Ahmed ),( Faisal Bashir ) 한국인터넷정보학회 2016 KSII Transactions on Internet and Information Syst Vol.10 No.6

Cloud storage as a service provides high scalability and availability as per need of user, without large investment on infrastructure. However, data security risks, such as confidentiality, privacy, and integrity of the outsourced data are associated with the cloud-computing model. Over the year`s techniques such as, remote data checking (RDC), data integrity protection (DIP), provable data possession (PDP), proof of storage (POS), and proof of retrievability (POR) have been devised to frequently and securely check the integrity of outsourced data. In this paper, we improve the efficiency of PDP scheme, in terms of computation, storage, and communication cost for large data archives. By utilizing the capabilities of JAR and ZIP technology, the cost of searching the metadata in proof generation process is reduced from O(n) to O(1). Moreover, due to direct access to metadata, disk I/O cost is reduced and resulting in 50 to 60 time faster proof generation for large datasets. Furthermore, our proposed scheme achieved 50% reduction in storage size of data and respective metadata that result in providing storage and communication efficiency.

Evaluation of Risk Factors Causing Cost Overrun in Road Projects in Terrorism Affected Areas Pakistan – a Case Study

Irfan Zafar,Tashfeen Yousaf,Sarfraz Ahmed 대한토목학회 2016 KSCE Journal of Civil Engineering Vol.20 No.5

The risks and uncertainties inherent to the construction industry are more than any other industry and this industry exhibits poor management of these risks. Hence, many projects fail to meet time schedules and budget targets. Transport sector is an important part of the construction industry and is vital to its growth. However this sector has been severely affected by delayed completion of the projects with exceeded cost. These issues are more pronounced in terrorism affected areas around the world, predominantly in Pakistan, Afghanistan and Iraq. Evaluation of Risk Factors Causing Cost Overrun in Road Projects in Terrorism Affected Areas: Pakistan - a Case Study. Pakistan being top ranked terrorism affected country among 85 terrorist affected countries around the world in 2012, has been taken as case study. In Pakistan, Federally Administrated Tribal Area (FATA) being the recipient of max casualties in 2012 is the focus of the study. After 9/11, FATA received maximum share of development projects especially road infrastructure however, these projects could not fulfill their desired purpose due to lack of evaluation of risks associated with the dynamics and culture of that area resulting in severe cost overrun of these projects. This study presents the mechanism to identify the key risk factors contributing to the failure of achieving budget targets of road projects in FATA and suggests measures to overcome them. The study is undertaken via a questionnaire based survey comprising of 18 cost overrun risk factors which were ranked using their mean weightage. Analysis of the results show that non-availability of suitable contractors, project location within FATA, idling cost of plant and equipment due to security threats, differing site conditions in a project and inaccurate survey and site investigation due to security threat were major factors responsible for cost overrun. Moreover, responsibility among the stakeholders for these risks was also established. The results of the study warrant adoption of proactive measures for effective management of these risks by owner, consultants and contractors to avoid budget escalation in road construction projects in terrorism affected area around the world.

Standardized Ileal Amino Acid Digestibility of Commonly Used Feed Ingredients in Growing Broilers

Ullah, Zafar,Ahmed, Gulraiz,Nisa, Mehr un,Sarwar, Muhammad Asian Australasian Association of Animal Productio 2016 Animal Bioscience Vol.29 No.9

This experiment was conducted to determine standardized ileal amino acid digestibility (SIAAD) of commonly used feed ingredients in poultry diets in Pakistan. These feed ingredients included corn, rice broken (RB), rice polishings (RP), wheat bran (WB), sunflower meal (SFM), cottonseed meal (CSM), guar meal (GM), soybean meal (SBM) from India and Argentine and fish meal (FM). The SIAAD of each ingredient was determined in triplicate using 21-days-old broilers. Day-old male broiler chicks (Hubbard${\times}$ Hubbard) were reared on corn-SBM based diet from 1 to 13 days and thereafter birds were fed experimental diets from day 14 to 21. Each diet was fed to 36 birds kept in six replicate cages, each cage had six birds. In cereals, the SIAAD of corn's amino acid (AA) (90.1%) was similar (p>0.05) to RB (89.0%). Isoleucine (97.8%) and lysine (96.9%) were highly digestible AA in corn and RB, respectively. Among cereal-by products, WB's SIAAD (76.9%) was same (p>0.05) as RP (71.9%). Arginine from WB (82.5%) and RP (83.2%) was highly digestible. However, threonine in WB (72.7%) and leucine in RP (69.6%) were the lowest digestible AAs. In plant protein meals, AAs from Argentine-SBM (85.1%) and Indian-SBM (83.4%) had higher (p<0.5) SIAAD than other protein meals. However, SIAAD of SFM (77.1%) and CSM (71.7%) was intermediate while GM (60.3%) exhibited the lowest (p<0.05) SIAAD among all ingredients. Arginine from GM (76.9%), CSM (85.8%), SBM-India (89.5%) and SBM-Argentine (91.5%) was highly digestible from indispensable AAs. In SFM, methionine (91.4%) SIAAD was the greatest. The average SIAAD of FM was 77.6%. Alanine from FM had the highest (84.0%) but cysteine (62.8%) had the lowest SIAAD. In conclusion, cereals i.e. corn and RB had higher (p<0.05) SIAAD of the cereals by-products. The SIAAD of RP and WB was same (p>0.05). The SBM from plant protein meals had higher (p<0.05) SIAAD than other studied feed ingredients. However, the GM had the lowest (p<0.05) SIAAD among protein meals.

Synthesis and Physicochemical Studies of Perovskite Manganite La<SUB>0.8</SUB>Ca<SUB>0.2</SUB>Nn<SUB>1-x</SUB>Co<SUB>x</SUB>O₃ (0 ≤ x ≤ 0.3)

D. Turki,Zafar Khan Ghouri,Saeed Al-Meer,Khaled Elsaid,M. I. Ahmad,Ahmed Easa,M. Ellouze,E. K. Hlil 한국자기학회 2017 Journal of Magnetics Vol.22 No.3

The physicochemical properties of La0.8Ca0.2Mn1−xCoxO₃ nanopowders as a function of Co content (x) have been investigated. La0.8Ca0.2Mn1−xCoxO₃ nanopowders were synthesized by sol-gel method and morphologically and structurally well characterized by Scanning electron microscopic (SEM), Infrared spectroscopic (IR) and Raman spectroscopic techniques. IR spectra shows peak at around 600 cm<SUP>−1</SUP> attributed to the stretching mode of MnO6 octahedral and peak at 700 cm<SUP>−1</SUP> assigned to La-Ca-O-Mn bending vibrations. Raman spectra indicate peaks at around 512 and 652 cm<SUP>−1</SUP> related to the Jahn-Teller octahedral distortions. The intensity of these peaks increases with increasing Co doping. The UV-visible spectra were measured in the frequency range of 200-800 nm and two energy gaps were found at 1.63 eV and 3.294 eV for x = 0, 0.1 and 0.3.

Allelopathic effects of red pepper (Capsicum annuum L.) and coriander (Coriandrum sativum L.) on early seedling growth of wheat (Triticum aestivum L.)

Iqbal, Muhammad Zafar,Ahmed, Lubna,Shafiq, Muhammad,Athar, Mohammad Techno-Press 2015 Advances in environmental research Vol.4 No.1

A pot experiment was conducted to assess the effects of red pepper (Capsicum annuum) and coriander (Coriandrum sativum) on seedling growth of wheat (Triticum aestivum). The aqueous extracts treatment of red pepper and coriander showed a significant (p < 0.05) reduction in root, shoot and seedling length, number of leaves and seedling dry weight of wheat (T. aestivum) as compared to control. The inhibitory different effect on growth of wheat (T. aestivum) was directly proportional to the increasing concentration (1, 2, 3, 4 and 5%) of aqueous extracts of red pepper and coriander as compared to control treatment (0%). The root, shoot, seedling length and number of leaves of T. aestivum significantly p < 0.05 decreased at 5% concentration of red pepper as compared to control. The root, shoot and seedling growth of T. aestivum was also significantly reduced at 1, 2, 3, 4 and 5% concentration of coriander as compared to control. The root, shoot and leaves dry weight of T. aestivum at 5% coriander extract treatment concentration decreased as compared to control. The tolerance in seedlings of T. aestivum to red pepper and coriander extract treatment was dose dependent as compared to control. The seedlings of T. aestivum showed low percentage of tolerance to pepper extract treatment than coriander extract treatment.

Bioenergy potential and thermochemical characterization of lignocellulosic biomass residues available in Pakistan

Aisha Abdullah,Ashfaq Ahmed,Parveen Akhter,Abdul Razzaq,Muhammad Zafar,Murid Hussain,Nasir Shahzad,Khaliq Majeed,Shahzad Khurrum,Muhammad Saifullah Abu Bakar,박영권 한국화학공학회 2020 Korean Journal of Chemical Engineering Vol.37 No.11

We evaluated the thermochemical properties and suitability of a variety of lignocellulosic biomass residues in Pakistan for energy production. Proximate, ultimate and calorific value analyses were performed to know the energy perspective, whereas thermogravimetric analysis was used to study the decomposition behavior of biomass samples under pyrolysis conditions. The moisture content, volatile matter, fixed carbon and ash content in the biomass samples were found within the range of 4.38-5.69%, 63.25-80.53%, 7.97-23.13%, and 7.12-14.35%, respectively. The range of carbon, hydrogen, and oxygen content was reported as 35.83-47.23%, 5.2-6.56%, and 45.6-58.55%, respectively. Lower values of sulfur and nitrogen content amongst the samples indicated that the biomass was environmentally friendly in terms of energy production. The heating value of the biomass was reported in the range of 15.20-18.44 MJ/kg. Fourier transform infrared spectroscopy showed the existence of hydroxyl, aldehydes, ketones, aromatic compounds, carbonyl compounds, ether, and halogen groups. Orange leaf biomass indicated a greater potential in producing bio-oil, whereas the horticulture biomass and mango leaves may have greater potential for biochar

Interactive Effect of Cobalt and Nitrogen on Growth, Nodulation, Yield and Protein Content of Field Grown Pea

Fahmida Mir Akbar,Mohsin Zafar,Abdul Hamid,Maqsood Ahmed,Abdul Khaliq,Muhammad Riaz Khan,Zahid ur Rehman 한국원예학회 2013 Horticulture, Environment, and Biotechnology Vol.54 No.6

Pea (Pisum sativum L.) has increasing nutritional, commercial, and economical value, and initial low supply of N and Co is needed to increase nodulation, yield, and profit. A field experiment in 2010 was conducted at the University of Poonch Rawalakot located in the hilly region of the state of Azad Jammu and Kashmir, Pakistan. The aim of the study was to evaluate the effects of fertilization of N and Co on growth, nodulation, seed yield, seed composition of, and uptake of N and Co by pea plant. Treatments included three levels of N (0, 30, and 60 kg N·ha-1 and represented as N0, N30, and N60, respectively) combined with three levels of Co (0, 10, and 20 g Co·ha-1and represented as Co0, Co10, and Co20, respectively), and the control represented as N0Co0. Results indicated that most of the morphological characteristics were increased with N60. The greatest shoot length, root length, and chlorophyll content were recorded in the N60Co20. The number of root nodules increased from 6 in the control to 19with fertilization of N and Co. Yield responses to N–Co fertilization occurred to all rates, and the highest yield,2536 kg·ha-1, was observed in the treatment N60Co10. Total N and Co uptake in the plant (shoot + root + seed)ranged between 16-147% and 3-331% over the control, while seed protein increased by 13–198% over the control by application of N and Co. This study demonstrates that N- and Co-deficient soils are likely to produce crops with low yields and seeds with low protein levels, and therefore, appropriate management of soil N and Co could be an effective approach to increase and sustain pea production in the small holding mountain ecosystems.

An Evaluation of Malaysian Consumers' Perceptions Towards Products Made in Korea: An Asia Pacific Marketing Perspective

Sohail, M. Sadiq,Ahmed, Zafar U. Korean Scholars of Marketing Science 2006 마케팅과학연구 Vol.16 No.1

The objective of this paper is to examine the country of origin effect of products made in the Republic of Korea. The study focuses on the questions of the sources of information in evaluating products; the evaluation of specific product dimensions by Malaysian consumers; and consumers' assessment of different product categories. It reports on the findings of a survey conducted in which 244 responses were obtained. The most common product information source was found to be through advertisements in television and radio.. Products made in Korea had been rated highly for its product style. Consumer electronics were generally found to be the popular preference of product category by Malaysian consumers. The managerial implications of our study are discussed and the limitations of the study are also examined.