http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
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).
Muhammad Ajaz Hussain,Khawar Abbas,Muhammad Sher,Muhammad Nawaz Tahir,Wolfgang Tremel,Mohammad Saeed Iqbal,Muhammad Amin,Munair Badshah 한국고분자학회 2011 Macromolecular Research Vol.19 No.12
This article presents the synthesis of novel hydroxypropylmethylcellulose (HPMC)-aspirin (ASP) conjugates,i.e. macromolecular prodrugs, through the reaction of HPMC with ASP after its in situ activation by 4-methylbenzenesulfonyl chloride. The highly pure ASP prodrugs obtained by this homogeneous and elegant esterification method were characterized using different spectroscopic and chromatographic techniques. Nanoparticulate drug design was successfully achieved by the conversion of free hydroxyls of the polymer into acetates. Transmission electron microscopy and scanning electron microscopy showed nanoparticle formation with the major population size distribution of around 450 nm. Nevertheless, the pharmacokinetics of the HPMC conjugates were studied using high performance liquid chromatography. The pharmacokinetic data indicated that a single dose of 132.6 mg of HPMC-ASP was well tolerated in animal studies without any adverse effects. The maximum plasma concentration (C_max) of HPMC-ASP was found to be 14.6 μg·L^-1 with a t_max of 1 h. The plasma half-life and clearance and the volume of HPMC-ASP distribution were 4.6 h, 3.23 L·h^-1, and 21.8 L·kg^-1, respectively. The elimination of HPMC-ASP followed first-order kinetics with r^2 of 0.9643. The results presented in this paper show the great potential of HPMCASP as a more effective, safe, and stable prodrug.
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
Muhammad Shabbir Shakir,Muhammad Kaleem Khosa,Khalid Mahmood Zia,Muhammad Saeed,Tanveer Hussain Bokhari,Muhammad Abid Zia 한국화학공학회 2021 Korean Journal of Chemical Engineering Vol.38 No.11
The Present study deals with synthesis of PVC/ABS/ZnO nanocomposites with Zinc oxide nanoparticles of particle size less than 50 nm by sonication and solution casting techniques. After characterization, such nanocomposite materials were subjected to thermal study, antibiofilm, antibacterial and antioxidant screening. Nanocomposites films showed higher thermal stability than pure polymer matrix loaded with different ZnO-Nps concentration with homogeneous distribution. Antibacterial studies were carried out against selected gram-positive bacteria: Staphylococcus aureus and gram-negative bacteria: Pseudomonas aeruginosa. Selective antibiofilm activity was studied against Staphylococcus aureus and Pseudomonas aeruginosa, which showed a higher to lower activity as a model pathogenic strains (~93 and ~89 at 160 g/ml concentration, respectively), while free radical scavenging capacity was assessed by DPPH, ABTH·+ and FRAP methods. PVC/ABS/ZnO nanocomposite showed larger zones of inhibition and higher antibiofilm and antioxidant activity than PVC/ABS polymer matrix. PVC/ABS/ZnO nanocomposite showed enhanced thermal stability and biological properties that qualify them for different biomedical and industrial applications.
Effects of elastic medium on buckling of microtubules due to bending and torsion
Taj, Muhammad,Hussain, Muzamal,Afsar, Muhammad A.,Safeer, Muhammad,Ahmad, Manzoor,Naeem, Muhammad N.,Badshah, Noor,Khan, Arshad,Tounsi, Abdelouahed Techno-Press 2020 Advances in concrete construction Vol.9 No.5
Microtubules buckle under bending and torsion and this property has been studied for free microtubules before using orthotropic elastic shell model. But as microtubules are embedded in other elastic filaments and it is experimentally showed that these elastic filaments affect the critical buckling moment and critical buckling torque of the microtubules. To prove that, we developed orthotropic Winkler like model and demonstrated that the critical buckling moment and critical buckling torque of the microtubules are orders of higher magnitude than those found for free microtubules. Our results show that Critical buckling moment is about 6.04 nNnm for which the corresponding curvature is about θ = 1.33 rad /㎛ for embedded MTs, and critical buckling torque is 0.9 nNnm for the angle of 1.33 rad/㎛. Our results well proved the experimental findings.
Nonlocal effect on the vibration of armchair and zigzag SWCNTs with bending rigidity
Hussain, Muzamal,Naeem, Muhammad Nawaz,Tounsi, Abdelouahed,Taj, Muhammad Techno-Press 2019 Advances in nano research Vol.7 No.6
Vibration analysis of carbon nanotubes (CNTs) is very essential field owing to their many promising applications in tiny instruments. In current study, the Eringen's nonlocal elasticity theory with clamped-clamped and clamped-free end conditions is utilized for the vibration analysis of armchair and zigzag SWCNTs. The Fourier method is utilized to solve the ordinary differential equation. The motion equation for this system is developed using a novel wave propagation method. Complex exponential functions have been used and the axial model depends on BCs that has been described at the edges of CNTs. The behavior of different nonlocal parameters is considered to find the vibrational frequency of SWCNTs. It is exhibited that the effect of frequencies against aspect ratio by varying the bending rigidity. It has been investigated that by increasing the nonlocal parameter decreases the frequencies and on increasing the aspect ratio increases the frequencies for both the tubes. To generate the fundamental natural frequencies of SWCNTs, computer software MATLAB engaged. The numerical results are validated with existing open text. Since the percentage of error is negligible, the model has been concluded as valid.
Non-local orthotropic elastic shell model for vibration analysis of protein microtubules
Muhammad Taj,Afnan Majeed,Muzamal Hussain,Muhammad N. Naeem,Muhammad Safeer,Manzoor Ahmad,Hidayat Ullah Khan,Abdelouahed Tounsi 사단법인 한국계산역학회 2020 Computers and Concrete, An International Journal Vol.25 No.3
Vibrational analysis in microtubules is examined based on the nonlocal theory of elasticity. The complete analytical formulas for wave velocity are obtained and the results reveal that the small scale effects can reduce the frequency, especially for large longitudinal wave-vector and large circumferential wave number. It is seen that the small scale effects are more significant for smaller wave length. The methods and results may also support the design and application of nano devices such as micro sound generator etc. The effects of small scale parameters can increase vibrational frequencies of the protein microtubules and cannot be overlooked in the analysis of vibrating phenomena. The results for different modes with nonlocal effect are checked.
Muhammad Yasir Mehboob,Riaz Hussain,Zobia Irshad,Muhammad Adnan 대한화학회 2021 Bulletin of the Korean Chemical Society Vol.42 No.4
Efficient hole transport materials for solar cell applications are gained huge intension of every scientist. Hole transport materials play a dominant role in solar cells as they provide high power conversion efficiency along with low cost, less toxic, and easy synthesis routs. Motivates from valuable literature, here efforts are being made to designed new novel hole transport materials for solar cell applications. Five new and highly efficient hole transport molecules (BT1–BT5) are designed after end-capped donor modifications of recently synthesized B3 (R) molecule. The photovoltaic, optoelectronic, and structural-property relationship of all designed molecules are extensively studied while using density functional theory and time-dependent density functional theory at MPW1PW91/6-31G(d,p) basis set. Low reorganizational energy of hole is observed in all designed molecules as compared to reference molecule which suggested that designed molecules have high hole mobility as compared to R molecule. Red-shifting in absorption spectrum of designed molecules (as compared to reference molecule) is also seen which offer high power conversion efficiency and high excited highest occupied molecular orbital to lowest unoccupied molecular orbital charge shifting. Low binding and excitation energies are observed in designed molecules. Molecular electrostatic potential, transition density matrix, hole–electron overlap as heat map, open circuit voltage, density of states, and complex study of BT5:PC61BM is also performed for all studied molecule. After all analysis, we believed that our theoretical designed molecules are superior to R molecule, thus we recommend these molecules to experimentalist for future development of highly-efficient solar cells.
Simulating vibration of single-walled carbon nanotube using Rayleigh-Ritz's method
Hussain, Muzamal,Naeem, Muhammad Nawaz,Taj, Muhammad,Tounsi, Abdelouahed Techno-Press 2020 Advances in nano research Vol.8 No.3
In this paper, a new method based on the Sander theory is developed for SWCNTs to predict the vibrational behavior of length and ratio of thickness-to-radius according to various end conditions. The motion equation for this system is developed using Rayleigh-Ritz's method. The proposed model shows the vibration frequencies of armchair (5, 5), (7, 7), (9, 9), zigzag (12, 0), (14, 0), (19, 0) and chiral (8, 3), (10, 2), (14, 5) under different support conditions namely; SS-SS, C-F, C-C, and C-SS. The solutions of frequency equations have been given for different boundary condition, which have been given in several graphs. Several parameters of nanotubes with characteristic frequencies are given and vary continuously in length and ratio of thickness-to-radius. It has been illustrated that an enhancing the length of SWCNTs results in decreasing of the frequency range. It was demonstrated by increasing of the height-to-radius ratio of CNTs, the fundamental natural frequency would increase. Moreover, effects of length and ratio of height-to-radius with different boundary conditions have been investigated in detail. It was found that the fundamental frequencies of C-F are always lower than that of other conditions, respectively. In addition, the existence of boundary conditions has a significant impact on the vibration of SWCNTs. To generate the fundamental natural frequencies of SWCNTs, computer software MATLAB engaged. The numerical results are validated with existing open text. Since the percentage of error is negligible, the model has been concluded as valid.