Partial sulfur doping induced variation in morphology of MnFe2O4 with enhanced electrochemical performance for energy storage devices

Abdullah Muhammad,Alharbi Fatemah Farraj,Khosa Rabia Yasmin,Alburaih Huda A.,Manzoor Sumaira,Abid Abdul Ghafoor,Ali Haitham Elhosiny,Waheed Muhammad Suleman,Ansari Muhammad Numair,Farid Hafiz Muhammad 한국화학공학회 2023 Korean Journal of Chemical Engineering Vol.40 No.6

Manganese ferrite offers several advantages when employed as an electrocatalytic material for supercapacitors, including outstanding cycle stability and energy capacity. When compared to identical-metal sulfides, specific capacitance (Csp) of MnFe2O4 remains inadequate. So, using the hydrothermal synthesis technique, partial sulfur doping of MnFe2O4 was achieved to investigate the synergetic effect of oxides and sulfides. Various spectroscopic and microscopic studies demonstrate that adding sulfur atoms into MnFe2O4 increases the lattice parameters, which improves electrochemical performance. At a current density around 2 A g−1, then calculating MnFe2O4 with partial sulfur doping has a Csp of 1,201.60 F g−1, that is greater than 784.0 F g−1 of pure MnFe2O4. Maximum energy density (Ed) of 93.62 Wh kg−1 was produced with a power density (Pd) of 749 W kg−1. The current study depicts that partial sulfur doping can enhance the electrochemical behavior of MnFe2O4. As a result, the present work shows more effective in field of energy storage by enhancing their poor electrochemical performance.

Quantum Chemical Designing of Efficient Sensitizers for Dye Sensitized Solar Cells

Abdullah, Muhammad Imran,Janjua, Muhammad Ramzan Saeed Ashraf,Mahmood, Asif,Ali, Sajid,Ali, Muhammad Korean Chemical Society 2013 Bulletin of the Korean Chemical Society Vol.34 No.7

Density functional theory (DFT) was used to determine the ground state geometries of indigo and new design dyes (IM-Dye-1 IM-Dye-2 and IM-Dye-3). The time dependant density functional theory (TDDFT) was used to calculate the excitation energies. All the calculations were performed in both gas and solvent phase. The LUMO energies of all the dyes were above the conduction band of $TiO_2$, while the HOMOs were below the redox couple (except IM-Dye-3). The HOMO-LUMO energy gaps of new design dyes were smaller as compared to indigo. All new design dyes were strongly red shifted as compared to indigo. The improved light harvesting efficiency (LHE) and free energy change of electron injection ${\Delta}G^{inject}$ of new designed sensitizers revealed that these materials would be excellent sensitizers. The broken coplanarity between the benzene near anchoring group having LUMO and the last benzene attached to TPA unit in all new design dyes consequently would hamper the recombination reaction. This theoretical designing will the pave way for experimentalists to synthesize the efficient sensitizers for solar cells.

Quantum Chemical Designing of Efficient Sensitizers for Dye Sensitized Solar Cells

Muhammad Imran Abdullah,Muhammad Ramzan Saeed Ashraf Janjua,Asif Mahmood,Sajid Ali,Muhammad Ali 대한화학회 2013 Bulletin of the Korean Chemical Society Vol.34 No.7

Density functional theory (DFT) was used to determine the ground state geometries of indigo and new design dyes (IM-Dye-1 IM-Dye-2 and IM-Dye-3). The time dependant density functional theory (TDDFT) was used to calculate the excitation energies. All the calculations were performed in both gas and solvent phase. The LUMO energies of all the dyes were above the conduction band of TiO2, while the HOMOs were below the redox couple (except IM-Dye-3). The HOMO-LUMO energy gaps of new design dyes were smaller as compared to indigo. All new design dyes were strongly red shifted as compared to indigo. The improved light harvesting efficiency (LHE) and free energy change of electron injection ΔGinject of new designed sensitizers revealed that these materials would be excellent sensitizers. The broken coplanarity between the benzene near anchoring group having LUMO and the last benzene attached to TPA unit in all new design dyes consequently would hamper the recombination reaction. This theoretical designing will the pave way for experimentalists to synthesize the efficient sensitizers for solar cells.

Tree species migration to north and expansion in their habitat under future climate: an analysis of eight tree species Khyber Pakhtunkhwa, Pakistan

Durrani Muhammad Abdullah,Raza Rohma,Shakil Muhammad,Sabir Shakeel,Danish Muhammad 한국생태학회 2024 Journal of Ecology and Environment Vol.48 No.1

Background: Khyber Pakhtunkhwa government initiated the Billion Tree Tsunami Afforestation Project including regeneration and afforestation approaches. An effort was made to assess the distribution characteristics of afforested species under present and future climatic scenarios using ecological niche modelling. For sustainable forest management, landscape ecology can play a significant role. A significant change in the potential distribution of tree species is expected globally with changing climate. Ecological niche modeling provides the valuable information about the current and future distribution of species that can play crucial role in deciding the potential sites for afforestation which can be used by government institutes for afforestation programs. In this context, the potential distribution of 8 tree species, Cedrus deodara, Dalbergia sissoo, Juglans regia, Pinus wallichiana, Eucalyptus camaldulensis, Senegalia modesta, Populus ciliata, and Vachellia nilotica was modeled. Results: Maxent species distribution model was used to predict current and future distribution of tree species using bioclimatic variables along with soil type and elevation. Future climate scenarios, shared socio-economic pathways (SSP)2-4.5 and SSP5-8.5 were considered for the years 2041–2060 and 2081–2100. The model predicted high risk of decreasing potential distribution under SSP2-4.5 and SSP5-8.5 climate change scenarios for years 2041–2060 and 2081–2100, respectively. Recent afforestation conservation sites of these 8 tree species do not fall within their predicted potential habitat for SSP2-4.5 and SSP5-8.5 climate scenarios. Conclusions: Each tree species responded independently in terms of its potential habitat to future climatic conditions. Cedrus deodara and P. ciliata are predicted to migrate to higher altitude towards north in present and future climate scenarios. Habitat of D. sissoo, P. wallichiana, J. regia, and V. nilotica is practiced to be declined in future climate scenarios. Eucalyptus camaldulensis is expected to be expanded its suitability area in future with eastward shift. Senegalia modesta habitat increased in the middle of the century but decreased afterwards in later half of the century. The changing and shifting forests create challenges for sustainable landscapes. Therefore, the study is an attempt to provide management tools for monitoring the climate change-driven shifting of forest landscapes.

Optimized Biodiesel Production and Environmental Assessment of Produced Biodiesel

Muhammad Saqib,Muhammad Waseem Mumtaz,Asif Mahmood,Muhammad Imran Abdullah 한국생물공학회 2012 Biotechnology and Bioprocess Engineering Vol.17 No.3

Present study deals with the optimization of biodiesel production using rapeseed oil as feedstock and NaOCH3 as a catalyst. Optimization of different reaction parameters, such as catalyst concentration, reaction temperature,reaction time. and alcohol to oil molar ratio, was done using response surface methodology (RSM). The optimal experimental conditions for biodiesel production were as follows: catalyst concentration (%) 0.30, reaction temperature 55oC, molar ratio 6.75, and reaction time 60 min. Under these optimal conditions, 97.5 percentage yield of biodiesel was obtained. The observed and predicted values of rapeseed oil methyl esters (ROMEs) yield showed a linear relationship. The fuel properties such as specific gravity 0.876 ± 0.01, flash point 168 ± 0.48oC, fire point 197.8 ±0.31oC, pour point -7 ± 0.060oC, cloud point -2 ± 0.10oC kinematic viscosity 4.42 ± 0.26 mm2/sec, and sulfur content 0.002 mg/Kg of the produced biodiesel show the suitability of rapeseed oil biodiesel, as fuel. Moreover, engine performance test of the Rapeseed oil biodiesel (rapeseed oil methyl esters, ROME) was examined. The results showed that CO and particulate matter (PM) emissions of the ROME were lower than those of diesel fuel. NOX emissions of the ROME were lower for B5, B20, B40, and B50, while higher for B80 and B100. These results show the environment benefits of biodiesel.

Pancreatitis-Primary Hyperparathyroidism Association: Case Report and Literature Review

Muhammad Abdullah,FRCS (England),FRCS (Glasgow) 대한갑상선-내분비외과학회 2002 The Koreran journal of Endocrine Surgery Vol.2 No.1

The relationship of cause and effect between acute pancreatitis and primary hyperparathyroidism (pHPT) continues to be debated. Critics see any association of pancreatitis with pHPT as only incidental or even a result of parathyroid surgery. Counter arguments claim that pancreatitis is actually a manifestation of pHPT and definitive management of such pancreatitis should be directed towards dealing with the hyperparathyroidism. Our paper aims to review the debate in the published medical literature starting from the first reporting of such association in 1947. In this controversy we add our own case of a 49-year old non-alcoholic man presenting with recurrent attacks of acute pancreatitis. Investigated with ultrasound, CT scan, ERCP and biochemical profiles, it was not until his 3<SUP>rd</SUP> admission that his raised serum calcium was acted upon. High intact parathyroid levels were confirmed. Open neck exploration found a solitary parathyroid adenoma. After surgery the serum calcium returned to normal and abdominal symptoms have not recurred in the subsequent three years. This supports our belief that acute pancreatitis is one of the symptoms of pHPT, often caused by a parathyroid adenoma and curable by its excision. Calcium and parathyroid profiles should be scrutinized in all fresh cases of acute pancreatitis. (Korean J Endocrine Surg 2002;2:55-57)

The Predictive Power of Multi-Factor Asset Pricing Models: Evidence from Pakistani Banks

Muhammad SALIM,Muhammad Arsalan HASHMI,A. ABDULLAH 한국유통과학회 2021 The Journal of Asian Finance, Economics and Busine Vol.8 No.11

This paper compares the performance of Fama-French three-factor and five-factor models using a dataset of 20 Pakistani commercial banks for the period 2011 to 2020. We focus on an emerging economy as the findings from earlier studies on developed countries cannot be generalized in emerging markets. For empirical analysis, twelve portfolios were developed based on size, market capitalization, investment strategy, and growth. Subsequently, we constructed five Fama-French factors namely, RM , SMB, HML, RMW, and CMA. The OLS regression technique with robust standard errors was applied to compare the predictive power of both the Fama-French models. Further, we also compared the mean-variance efficiency of the Fama-French models through the GRS test. Our empirical analysis provides three unique and interesting findings. First, both asset pricing models have similar predictive power to explain the expected portfolio returns in most cases. Second, our results from the GRS test suggest that there is no noticeable difference in the mean-variance efficiency of one asset pricing model over the other. Third, we find that all factors of both Fama-French models are statistically significant and are important for explaining the volatility of expected commercial bank returns in the context of Pakistan.

The Impact of Microfinance on Households' Socioeconomic Performance: A Proposed Mediation Model

ABDULLAH, W Muhammad Zainuddin B Wan,ZAINUDIN, Wan Nur Rahini Aznie Bt,ISMAIL, Sarina Binti,HAAT, Mohd Hassan Che,ZIA-UL-HAQ, Hafiz Muhammad Korea Distribution Science Association 2021 The Journal of Asian Finance, Economics and Busine Vol.8 No.3

Economic deprivation of households remains a significant economic issue in the world. Researchers have shown great concern in identifying crucial factors to enhance poor households' socio-economic performance. Therefore, this paper aims to develop a new conceptual framework to investigate the influence of different microfinance services on households' socioeconomic performance using moderated mediation analysis of various crucial factors. Focus-group interviews with managements of the microfinance institution, i.e. Amanah Ikhtiar Malaysia (AIM), and a systematic literature review were conducted for this purpose, and a new framework for the future study has been developed. The result from focus-group interviews and systematic literature review propose microfinance financial services, training programs, and business coaching as independent factors, whereas household socioeconomic performance as a dependent factor in the proposed model. Specifically, this study provides the direction to scholars to empirically test the direct relationship between financial services and household socioeconomic performance and the indirect relationship between training programs, business coaching, and household socioeconomic performance. Further, microfinance institutions' service efficiency is also included as a moderator that can strengthen microfinance services' effectiveness. The study also provides useful implications for policymakers, financial institutions, households, micro-enterprises, and researchers to better understand microfinance interventions and household economic mechanisms.

Growth, carcass traits, cecal microbial counts, and blood chemistry of meat-type quail fed diets supplemented with humic acid and black cumin seeds

Muhammad Arif,Abdur Rehman,Mohamed E. Abd El-Hack,Muhammad Saeed,Fateh Khan,Muhammad Akhtar,Ayman A. Swelum,Islam M. Saadeldin,Abdullah N. Alowaimer 아세아·태평양축산학회 2018 Animal Bioscience Vol.31 No.12

Objective: The present study attempted to determine safe and sufficient growth promoters in poultry feeding. Methods: A total of 520 seven-day-old quail chicks were randomly allotted to eight treatment groups in a 4×2 factorial design experiment to evaluate the effect of different levels of humic acid (HA) and black cumin (BC) seed and their interactions on growth, carcass traits, gut microbes, and blood chemistry of growing quails. Quails were randomly distributed into 8 groups in a 4×2 factorial design, included 4 HA levels (0, 0.75, 1.5, and 2.25 g/kg diet) and 2 BC levels (0 or 5 g/ kg diet). Results: Increasing HA level associated with a gradual increase in final weight, feed intake and body weight gain along with an improvement in feed conversion ratio. Dietary addition of 5 g BC powder/kg diet gave similar results. The highest level of HA (2.25 g/kg diet) recorded the best values of carcass weight, breast yield, intestinal length, and intestinal weight comparing with the control and other HA levels. Total viable microbial counts decreased (p<0.05) with increasing levels of HA except the intermediate level (1.5 g/kg diet). The concentration of serum cholesterol and low density lipoprotein (excluding that 0.75 g HA) decreased (p<0.05) and high density lipoprotein increased (p = 0.034) along with increasing HA level. The interaction between the 2.25 g HA×5 g gave the best results regarding most studied parameters. Conclusion: These findings indicated that HA combined with BC could be used as effective growth promoters, with the recommended level being 2.25 g HA+5 g BC/kg of quail diet.

Constrained model predictive control of proton exchange membrane fuel cell

Muhammad Abdullah,Moumen Idres 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.9

A constrained model predictive control (MPC) is designed to regulate the air flow rate of proton exchange membrane fuel cell(PEMFC). Oxygen excess ratio, compressor flow rate and supply manifold pressure are constrained to avoid oxygen starvation, surge andchoke phenomena. This is achieved by manipulating compressor voltage and stack current. The choice of the manipulated input to satisfya constraint is investigated. Surge and choke avoidance is successful, when compressor voltage is manipulated. When stack current isutilized to satisfy surge and choke constraints, a large unrealistic current is needed. Oxygen starvation is successfully avoided utilizingstack current, while compressor voltage manipulation fails to prevent oxygen starvation. Thus, a current governor is implemented to handleoxygen starvation, while the compressor voltage is constrained to avoid surge and choke. Quadratic programming optimization,Laguerre and exponential weight function are employed to reduce the computational burden of the controller. The simulation resultsprove that the proposed controller managed to satisfy all constraints without any conflict.