Jamshoro, Pakistan
Jamshoro, Pakistan

The University of Sindh , is a public research university located in the residential area of Jamshoro, Sindh, Pakistan. It is one of the oldest universities in Pakistan, and as of 2013 was ranked in eighth in terms of "general category" by the Higher Education Commission of Pakistan.Founded in 1947 in Karachi, the university was relocated to Hyderabad where the university began functioning as a full-fledged teaching university. There are four law colleges and various other colleges affiliated with the Sindh University. The university is noted for research in literature, natural science, philosophy, and Sindhology. The university is also a member of the Association of Commonwealth Universities of the United Kingdom. Wikipedia.

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Positive position feedback control is the most common resonant control technique that has been studied for last three decades. As a low-pass filter, positive position feedback is very sensitive to low-frequency disturbances. To overcome this shortcoming of positive position feedback controller, negative derivative feedback controller, which acts as a bandpass filter and can effectively control the lower and higher frequency disturbances, has been developed recently. So far, there is no comparison work between positive position feedback and negative derivative feedback on flexible manipulator system. Consequently, to fill this gap, in this article, both positive position feedback and negative derivative feedback controllers are applied experimentally and analysed in terms of settling time and vibration attenuation at different damping ratios on a single link flexible manipulator featuring piezoelectric actuator. Moreover, robustness with respect to natural frequency variation is studied for the first time on flexible manipulator system. Based on experimental study conducted on the particular system developed in this article, it has been observed that negative derivative feedback controller is more effective than positive position feedback controller based on evaluated performance measures. © The Author(s) 2017.

Hong Y.,Zhejiang University | Soomro M.A.,University of Sindh | Ng C.W.W.,Hong Kong University of Science and Technology
Computers and Geotechnics | Year: 2015

Development of underground transportation systems often involve twin tunnels, which may encounter existing pile groups during construction. Since many previous studies mainly focus on the effects of single tunnelling on single piles, settlement and load transfer mechanism of a pile group subjected to twin tunnelling are not well investigated and understood. To address these two issues, two three-dimensional centrifuge tests were carried out in this study to simulate side-by-side twin tunnels (excavated one after the other on both sides of the pile group) at two critical locations relative to the pile group, namely next to (Test TT) and below the toe of the pile group (Test BB). Moreover, numerical back-analyses of the centrifuge tests are conducted by using a hypoplastic model, which takes small-strain stiffness into account. Both measured and computed results show that the induced tilting of the pile group in Test TT is significantly larger than that in Test BB, with a maximum percentage difference of 120%. On the other hand, a slightly smaller (about 13%) settlement of the pile group is induced in Test TT, as compared to that in Test BB. This is because the pile group in Test TT is partially located within the major influence zone of tunnelling-induced ground settlement while the entire pile group in Test BB is bounded by the major influence zone of ground settlement. Two distinct load transfer mechanisms due to twin tunnelling are identified, i.e., the load in the pile group in Test TT transfers downwards from the pile shaft to the pile toe while the load in the pile group in Test BB transfers upwards from the pile toe to the pile shaft. Apart from load transfer along each pile, load re-distribution also occurs among piles during twin tunnelling. In both Tests TT and BB, axial load at pile head only reduces at a pile closet to the advancing tunnel face and the reduction is re-distributed to the other three piles. The load re-distribution among piles results in a maximum increase of axial force of 10% in Test TT. © 2014 Elsevier Ltd.

Yilmaz E.,Selcuk University | Memon S.,University of Sindh | Yilmaz M.,Selcuk University
Journal of Hazardous Materials | Year: 2010

Two β-cyclodextrin (β-CD)-based polymers were synthesized using 4,4′-methylene-bis-phenyldiisocyanate (MDI) or hexamethylenediisocyanate (HMDI) as a cross linking agent in dimethylformamide and used as sorbents for the removal of azo dyes (Evans Blue and Chicago Sky Blue), as well as aromatic amines (benzidine, p-chloroaniline and α-naphthalamine) from aqueous solutions. The sorption experiments were carried out by using batch-wise procedure involving the determination of pH effect, sorbate concentration and contact time. Moreover, from the equation isotherms such as Langmuir and Freundlich were successfully applied to model the experimental data. From the results polymer 2 was found to be a better sorbent for both azo dyes and the aromatic amines as compared to polymer 1 as proved by Langmuir isotherm model. The proposed sorption mechanism involved several kinds of interactions: physical adsorption, hydrogen bonding and formation of an inclusion complex due to the β-CD molecules through host-guest interactions. © 2009 Elsevier B.V. All rights reserved.

Memon S.,University of Sindh | Memon N.,University of Sindh | Latif Y.,University of Sindh
Journal of Hazardous Materials | Year: 2011

The present work explores sorption behavior of calix[4]arene based silica resin to remove α and β endosulfan isomers from aqueous solution. The efficiency of resin was checked through both batch and column sorption methods. In both methods, the sorption parameters, i.e. pH, equilibrium time, shaking speed and sorbent dosage were optimized as 2, 60min, 125rpm and 50mg, respectively. Freundlich and Langmuir sorption isotherm models were applied to validate the sorption process. The data obtained in both models reveal that the sorption is favorable. Column sorption data were analyzed through Thomas model to calculate kinetic coefficient kTH and maximum sorption capacity qo of the resin, which were found to be 6.18 and 5.83cm3mg-1min-1 as well as 1.11 and 1.08mgg-1 for α and β endosulfan, respectively. Kinetics of sorption shows that it follows pseudo second order rate equation. The optimized method has also been applied to real water samples and the results show that calix[4]arene based silica resin is an effective sorbent to remove endosulfan from waste waters. © 2010 Elsevier B.V.

Maheshwari N.,University of Sindh
Saudi journal of kidney diseases and transplantation : an official publication of the Saudi Center for Organ Transplantation, Saudi Arabia | Year: 2010

This hospital-based cross-sectional comparative observational study was performed to determine the pattern of lipid profile in patients on maintenance hemodialysis. The study was performed at the Department of Nephro-Urology, Liaquat University Hospital, Hyderabad, Pakistan from April 2008 to June 2008. Fifty patients with end-stage renal disease on maintenance hemodialysis (MHD) were studied. They comprised of 31 males and 19 females, the mean duration on HD was 7.58 +/- 2.05 yrs, with frequency of two to three sessions per week and each session lasting for four hours. Additionally, 25 healthy volunteers (16 male, 9 female) were also studied. After obtaining informed, written consent, general information of each patient was recorded on the proforma. After 12-hours fasting, blood samples were drawn from the arterio-venous fistula before starting dialysis. The total cholesterol, triglyceride (TG) or low density lipoprotein (LDL) levels more than 95th percentile for age and gender or high density lipoprotein (HDL) less then 35 mg/dL was defined as dyslipidemia. Descriptive and inferential statistical analysis were performed using SPSS version 16.0. The age among MHD and control groups was 47.88 +/- 13.92 and 54.56 +/- 11.16 years respectively. Serum TG and lipoprotein-a (LPa) were significantly increased (P = < 0.001 for each) while HDL-c was significantly lower (P = < 0.001) in MHD patients than in the control group. The serum cholesterol, LDL-c, VLDL-c and chylomicron levels were not significantly different in the two groups. Our study suggests that patients on MHD show abnormalities of lipid metabolism like hypertriglyceridemia, elevated lipoprotein-a and low HDL-c, which could contribute to atherosclerosis and cardiovascular disease that may increase the morbidity and mortality in these patients.

Hyder Ali Muttaqi Shah S.,University of Sindh | Qi H.,Shandong University
Nonlinear Analysis: Real World Applications | Year: 2010

In this work, we have discussed some simple flows of a viscoelastic fluid with fractional Burgers' model in an annular pipe. The fractional calculus approach is introduced in the constitutive relationship of a Burgers' fluid model. Exact analytical solutions are obtained by using Laplace and Weber transforms for two types of flows, namely: Poiseuille flow and Axial Couette flow. © 2009 Elsevier Ltd. All rights reserved.

Hyder Ali Muttaqi Shah S.,University of Sindh
Nonlinear Analysis: Real World Applications | Year: 2010

The aim of this work is to discuss some unidirectional flows of a viscoelastic fluid between two parallel plates with fractional Burgers' fluid model. The exact analytical solutions for Plane Poiseuille and Plane Couette flows are obtained by using the finite Fourier sine transform and the Laplace transform. Moreover, the graphs are plotted to show the effects of different parameters on the velocity field. © 2009 Elsevier Ltd. All rights reserved.

Ali Muttaqi Shah S.H.,University of Sindh
Meccanica | Year: 2010

In this article, fractional calculus approach is used in the constitutive relationship of a Burgers' fluid model. Integral transforms are used to calculate the velocity and the stress fields for some helical flows of a Burgers' fluid with fractional derivative. Moreover, the behavior of different physical parameters involve in the Burgers' fluid model is analyzed through several graphs. Copyright © 2009 Springer Science+Business Media B.V.

Shah N.,University of Sindh
Journal of Enterprise Information Management | Year: 2011

Purpose: This paper aims to examine the relationships and predictive power of organisational justice factors such as distributive and procedural justice along with demographic factors towards the employee readiness for organisational change in a developing country. Design/methodology/approach: The paper uses random sampling of large public sector organisations of a developing country. This is a cross-sectional study where the researcher has used a self-administered survey questionnaire for data collection. The researcher used analytical techniques such as descriptive statistics, factor loading and Pearson's correlations. Finally, hypotheses were tested using the multiple regression analysis on to Statistical Package for Social Sciences (SPSS) version 15.0 for Windows. Findings: It is concluded that employees of public sector organisations in a developing country can develop their positive attitudes and behaviours for organisational change on the basis of distributive and procedural justice. Furthermore, the findings of the paper hold that demographic variables such as gender, age and marital status have no positive and significant relationships with employee readiness. Research limitations/implications: This study contributes to the literature on change management, human resources management, organisational behaviours and organisational development. This study may support the management and practitioners of change management in assessing and evaluating organisational change programmes, particularly in the developing country. Originality/value: The originality of the paper lies in the use of multivariate statistics on the organisational justice variables in order to examine the attitudes and behaviours of the employees of a public sector employer of a developing country. © Emerald Group Publishing Limited.

Jilani S.,University of Sindh
Saudi Journal of Biological Sciences | Year: 2013

In Pakistan, to increase agricultural production, higher amounts of fertilizers and pesticides are being used. The residues of the applied pesticides stay in the environment and therefore causing contamination of air, water and land. Moreover, agricultural industries are also contributing relatively high quantities of toxic pesticides into the environment. Since most of them have no treatment facilities. These pesticides may be toxic, mutagenic or carcinogenic. They may be bioaccumulated or biomagnified by the biota. Therefore its removal from environmental systems needs special attention. In this study, bacterial isolate, Pseudomonas, designated as IES- Ps-1, was used to assess its potential for pesticide removal from industrial wastewater using the biosimulator (activated sludge process). During experimental studies conducted in the flask as well as in biosimulator, it was observed that IES- Ps-1 grows normally at low concentrations of added insecticides when compared with the control test (without pesticide). However, at high concentrations the microbial count decreased but no death occurred and the culture remained in lag phase. In many cases, the growth of organisms in the presence of the particular substrate serves as an indication about its metabolic potential. However, to confirm these results, chemical oxygen demand (COD) and HPLC analysis were performed. Under aerobic culture conditions using mechanical aerators in biosimulator, almost complete removal of Cypermethrin at 20. mg/L dose occurred during 48. h. The study findings indicate that IES- Ps-1 strain, can be used for the treatment of the pesticide contaminated environment. Such study may be valuable to scientist and engineers, who are trying to develop methods for the treatment of toxic organic waste using the biological treatment process. © 2013 King Saud University.

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