Optimization analysis of the absorption-stabilization process for fluid catalytic cracking unit

Hussain Muhammad Saddam,Ahmed Ashfaq,Yibin Liu,Amin Muhammad Nadeem,Zahoor Tahir,Saleem Muhammad Afnan,Roh Kosan,Hussain Murid,Abu Bakar Muhammad Saifullah,박영권 한국화학공학회 2023 Korean Journal of Chemical Engineering Vol.40 No.7

The absorption-stabilization process (ASP), an important part of petroleum refinery used in the end-use products of petroleum (such as stable gasoline, liquid petroleum gas, and dry gas), is energy-intensive and has low product quality. Aspen Plus process simulator was used for the development of the ASP process model. The developed process model was validated with the actual plant data. The validated model was used to optimize to minimize the cost of the ASP. This work shows that the optimization analysis of the ASP can further improve the product quality and reduce thermal energy consumption. In the new process, changing feeding parameters of supplementary absorption oil, stripping tower intermediate reboiler, and feeding position of stabilization tower reduced the C3 contents of dry gas considerably and lowered the C2 and lighter contents of LPG. Additionally, the new process saved 1.32 MW of thermal energy consumption compared with the existing process. The operating cost has been reduced from 10.921 million USD annually to 9.830 million USD per year. Furthermore, the cost-saving effect of this optimization is about 9.99% (1.091 million USD per year).

The Effect of Corporate Governance Practices on Firm Performance: Evidence from Pakistan

Hussain Muhammad,Ashfaq U. Rehman,Muhammad Waqas 한국유통과학회 2016 Asian Journal of Business Environment (AJBE) Vol.6 No.1

Purpose – The purpose of this study is to investigate the effect of corporate governance practices such as (board size, board composition, CEO duality and audit committee) on the performance of selected Pakistani firms. Research design, data, and methodology – This study examines corporate governance structure by using the data of 80 non-financial firms listed on Karachi Stock Exchange Pakistan during 2010-2014. Hypotheses of the study were tested by using both descriptive and inferential statistics. Result – The findings indicate that board size and audit committee is positively related to the firm performance (ROA & ROE). In contrast, board composition and CEO duality are negatively related to the firm performance (ROA & ROE). As far as controlling variables is concerned, leverage is negative, whereas firm size is positively related to all measures of performance. Conclusions – Empirical findings concluded that corporate governance practices affect the firm performance. Therefore, it is suggested that managers should understand the governance mechanisms to work more efficiently in the firm

Effects of optimum doses of nitrogen, phosphorus, potassium and calcium on silkworm, Bombyx mori L., growth and yield

Muhammad A. KHAN,Waseem AKRAM,Muhammad ASHFAQ,Hafiz A. A. KHAN,이종진,김연국 한국곤충학회 2010 Entomological Research Vol.40 No.6

Silkworm rearing has been an income source for small-holding farmers in Pakistan. Over the years efforts have been made to improve silkworm quality and quantity and thus develop better prospects for increasing yield and income. Mulberry leaves Morus alba L. in a series of experiments have been supplemented with various nutrients in different doses and combinations. Relative success has been achieved in this context. In our present experiments on silkworm Bombyx mori L., we fed the larvae on mulberry leaves supplemented with different doses of N (0.2%), P (0.1%), K (0.3%) and Ca (0.1%) at 26 ± 3°C with 65 ± 5% relative humidity. The results showed better outputs in terms of food consumption (72.55 g/10 larvae), coefficient of utilization (76.45%), body weight (70.07 g/10 larvae) and body length (8.56 cm/larvae) than where simple mulberry leaves were offered. Our net gains with these production parameters have been in terms of heavier cocoons with and without pupa (2.25 and 0.69 g/cocoon), respectively.

Integrated adsorptive and photocatalytic degradation of pharmaceutical micropollutant, ciprofloxacin employing biochar-ZnO composite photocatalysts

Muhammad Amir,Tahir Fazal,Javed Iqbal,Aamir Alaud Din,Ashfaq Ahmed,Asim Ali,Abdul Razzaq,Zulfiqar Ali,Muhammad Saif Ur Rehman,박영권 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.115 No.-

The expensive carbonaceous substrates including graphene, reduced graphene oxide, carbon nanotubeshave been coupled with ZnO to improve the properties and photocatalytic performance of carbon basedZnO photocatalysts. To replace these expensive materials, biochar offers as a low-cost alternative to preparebiochar-based photocatalysts. In this study, Calotropis gigantea leaves derived biochar-ZnO (BC-ZnO)composites were synthesized to overcome the ZnO related problems (charge recombination, wider bandgap, and poor visible light absorption). Different BC-ZnO (BCZ-1–3) composites were characterized toevaluate their intrinsic properties and composites were employed to degrade ciprofloxacin (CIP). BCZ-3composite exhibited slower recombination of electron-hole pairs, lower band gap (2.97 eV), and betterlight absorption in visible region than ZnO. The enhanced adsorptive-photocatalytic degradation efficiencywas attained up to 98.5% using BCZ-3 than BC (46.2%) and ZnO (41.4%). The O2 and OH radicalswithin BCZ-3 are dominant reactive species indulged in CIP photocatalytic degradation. BCZ-3 photocatalystexhibits 80% degradation of CIP after four regeneration cycles. The maximum adsorption capacitywas achieved 54.18 mg g1 for BCZ-3 than BC (46.20 mg g1) and ZnO (15.55 mg g1). The results showthat BCZ-X composites can be used as stable, efficient, economical, and sustainable composite for therecovery of pharmaceutical wastewater.

Some Biochemical Abnormalities Caused by Cypermethrin in adults of Tribolium castaneum (Herbst.)

Muhammad Ashfaq,Khalid Shahid Mehmood,Akram Waseem,Hussain Riaz,Lee Jong-Jin 한국응용곤충학회 2003 한국응용곤충학회 학술대회논문집 Vol.2003 No.1

Some Biochemical Abnormalities Caused by Cypermethrin in adults of Tribolium castaneum (Herbst.)

ASHFAQ, Muhammad,shahid Mehmood KHALID,Waseem AKRAM,Riaz HUSSAIN,이종진 한국곤충학회 2004 Entomological Research Vol.34 No.1

Biochemical effects of sub lethal doses LC10 and LC20 of cypermethrin were studiedon some enzymes and macromolecule activities of adult beetles of Tribolium castaneum (Herbst.).Cypermethrin caused disturbances in levels of all biochemical components under study. The doseof 0.78 ppm caused abnormalities in α-amylase and FAA by increasing their activities i.e.,45.45% and 21.97% significantly. The higher sub lethal dose of 2.62 ppm disturbed all theparameters (AcP, α-amylase, soluble protein and FAA) except AkP, which was decreased by93.06%. Moreover, sub lethal doses either increased or decreased the levels of all parameters nonsignificantlyexcept AkP and FAA which were effected significantly by 87.92% and 14.29% atlower and higher doses, respectively. In the present studies, cypermethrin significantly enhancedthe activity of AkP in both susceptible and resistant strains of T. castaneum adult beetles whileFAA contents were increased significantly in resistant strain only. The activity of α-amylase wassignificantly lowered in susceptible strain only.

The Relationship between Working Capital Management and Profitability: A Case Study of Tobacco Industry of Pakistan

Hussain Muhammad,Ashfaq U Rehman,Muhammad Waqas 한국유통과학회 2016 KODISA ICBE (International Conference on Business Vol.2016 No.-

Firms can use working capital management which is one of the essential determinants to influence their profitability. The main theme of present study is to investigate the relationship between working capital management and profitability of Tobacco Industry of Pakistan. This study is based on secondary data collected from financial statements of selected companies of Tobacco Industry of Pakistan for the period of 2005-2014. For data analysis, both descriptive and inferential statistics were used. Correlation analysis is used to check the relationship between the variables, while multiple regression analysis is used to examine the effects of working capital management on profitability of firms. The result reveals that there is a strong negative relationship between variables of working capital management and profitability of Tobacco Industry of Pakistan. This means that as the cash conversion cycle increases, it will lead to declining of firm profitability and managers can create a positive value for shareholders by reducing the cash conversion cycle at optimal level. The study concludes that managers can create value for shareholders by managing the working capital well designed and implemented, and by keeping each components of it at optimal level.

The Relationship between Working Capital Management and Profitability: A Case Study of Tobacco Industry of Pakistan

Hussain Muhammad,Ashfaq U. Rehman,Muhammad Waqas 한국유통과학회 2016 The Journal of Asian Finance, Economics and Busine Vol.3 No.2

Firms can use working capital management which is one of the essential determinants to influence their profitability. The main theme of present study is to investigate the relationship between working capital management and profitability of Tobacco Industry of Pakistan. This study is based on secondary data collected from financial statements of selected companies of Tobacco Industry of Pakistan for the period of 2005-2014. For data analysis, both descriptive and inferential statistics were used. Correlation analysis is used to check the relationship between the variables, while multiple regression analysis is used to examine the effects of working capital management on profitability of firms. The result reveals that there is a strong negative relationship between variables of working capital management and profitability of Tobacco Industry of Pakistan. This means that as the cash conversion cycle increases, it will lead to declining of firm profitability and managers can create a positive value for shareholders by reducing the cash conversion cycle at optimal level. The study concludes that managers can create value for shareholders by managing the working capital well designed and implemented, and by keeping each components of it at optimal level.

Management of Fruit Flies (Diptera: Tephritidae) of the Most Perishable Fruits

KHAN, Muhammad Ahsan,Muhammad ASHFAQ,Waseem AKRAM,이종진 한국곤충학회 2005 Entomological Research Vol.35 No.2

Biological nitrogen fixation by the microorganisms in the gut of termites is one of the singularly important symbiotic processes, since termites invariably thrive on nitrogen poor diet. Two isolates of free living aerobic and facultative anaerobic N fixing bacteria were obtained from the guts of fungus cultivating termite, Macrotermes sp. Among the total bacterial isolates from termite gut, the per cents of N fixing aerobes viz., Azotobacter and Beijerinckia spp were 49% and 37% from the salivary gland while facultative N fixing anaerobe viz., Klebsiella and Clostridium contributed (51% and 93%). The free living aerobic bacteria were identified as Azotobacter spp (19×104 CFU mL-1) and Beijerinckia (13.2×104 CFU mL-1) from the salivary gland of the termite; interestingly, foregut, mid gut and hind gut registered a low population of these bacteria. The isolates of Azotobacter were smooth, glistening, vicid in nature, rods, gram negative and cyst forming. Isolates of Beijerinckia sp. produced copious slime, tenacious, rods, gram negative with no cyst formations. Both the isolates emitted green fluorescence and produced acid. Facultative N fixing anaerobes were harbored in the hind gut. The isolates were identified as Klebsiella (20×104 CFU mL-1) and Clostridium pasteurianum 39.1×104 CFU mL-1. Klebsiella were straight rods arranged singly or in pairs, non-motile, gram negative, whereas Clostridium pasteurianum was viscoid, motile with terminal spores. A positive correlation was observed between the extractable of these isolates and soil aggregation. The aggregates formed by the isolates increased soil aeration, porosity, water holding capacity and helped in better plant growth. Thus, the gut microflora of termite, apart from harnessing nitrogen from the atmosphere, also helps improving soil fertility.

A comparative study of linear control strategies on the aerodynamics twin rotor system

Adnan Qayyum Shah,Muhammad Awais,Muhammad Zafar,Ashfaq Ahmed,Muhammad Mudassar,Muhammad Muneer,Memoona Saif,Abdul Razzaq,Seong Ho Jang,김선형,박영권 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.8

This work presents the comparative study among pole-placement (PP), optimalcontrol using output-feedback (OCOF), linear-quadratic regulator (LQR), and PID controllers for the twin rotor multi-input multi-output system (TRMS). The pitch and yaw are key attributes for stabilizing the TRMS MIMO system and control of flight. The main objective of this study is to use these classical controller techniques to monitor the pitch and yaw angles of TRMS and show the result of these techniques. Simulation results depicts the actual performance and reveals how PP outperforms the other techniques.