saif ullah - Academia.edu (original) (raw)

Papers by saif ullah

Pakistan Journal of Social Research, 2021

The water supply and sanitation sector has always been overlooked in the comparison to the other ... more The water supply and sanitation sector has always been overlooked in the comparison to the other sectors both in the sense of budgetary allocation, in sustainability of development projects as well as execution of drinking water supply, sanitation schemes and provision of potable water strategies. The drinking water and sanitation system are closely linked with each other. The Government of Pakistan established the National Drinking Water Policy in September 2009, with the goal of providing clean and safe drinking water to the entire Pakistani population by 2025, including the poor and vulnerable, at a reasonable rate. The National Sanitation Policy of Pakistan was prepared in 2016, but recently conditions are adverse. In the Pakistan the sewerage systems are not only properly managed, out lived, inappropriate and leakages problems of sewer pipelines with major part of un-served population but also contribute towards water systems contamination and ground water as well as surface wa...

On the basis of the reported air quality index API and air pollutant monitoring data obtained at ... more On the basis of the reported air quality index API and air pollutant monitoring data obtained at thePeshawar city over the last seven years, the characteristics of air quality prominent pollutants andvariation of the average annual concentrations of SO2, NO2 total suspended particulate TSP fineparticulates PM10 CO and dust fall in Peshawar were analyzed. Results showed that SO2 and NO2were the prominent pollutants in the ambient air environment of Peshawar. Of the prominentpollutants TSP accounted for nearly 63 % SO2, 32.8 ppb NO2, 147 ppb of CH4, 13.8 ppb of CO, 94.5µg/m3 of MC and 0.60 ppb of O3 respectively in 2013. NO2 to SO2 comparison ratio initially declinedto 39.3 in 2009 and then starts to increase to 42.5 in 2010 while in 2013 reached upto 44.8 and O3 toSO2 ratio in the last year of observation, the ratio drop to 0.01830 µg/m3. Concentrations of airpollutants have shown a upward trend in recent years but they are generally worse than ambient airquality standards for EPA-US...

Digestive and Liver Disease, 2021

Chaos, Solitons & Fractals, 2020

Elsevier has created a COVID-19 resource centre with free information in English and Mandarin on ... more Elsevier has created a COVID-19 resource centre with free information in English and Mandarin on the novel coronavirus COVID-19. The COVID-19 resource centre is hosted on Elsevier Connect, the company's public news and information website. Elsevier hereby grants permission to make all its COVID-19-related research that is available on the COVID-19 resource centre-including this research content-immediately available in PubMed Central and other publicly funded repositories, such as the WHO COVID database with rights for unrestricted research re-use and analyses in any form or by any means with acknowledgement of the original source. These permissions are granted for free by Elsevier for as long as the COVID-19 resource centre remains active.

International Journal of Business and Management, 2016

This paper investigates the role of managerial entrenchment in the decision to hire an investor r... more This paper investigates the role of managerial entrenchment in the decision to hire an investor relations specialist. Managers of small and mid-cap firms spend considerable resources on hiring investor relations (IR) firms. This paper proposes a hypothesis to explain this spending. We argue that more entrenched managers are less likely to hire IR firms, because such managers are less likely to have their compensation tied to stock returns and be more wary of outside attention from the market. Using a common definition of managerial entrenchment, we show that entrenched managers are indeed less likely to hire an IR firm. We also examine the relationship between the method of payment of the IR firm (cash or stock) and future performance of the client. If an IR firm is paid in stock, it has an incentive to expend more effort on its client's behalf, thus leading to increased client performance. Our evidence shows that there is indeed a positive relationship between payment in stock and future client performance.

Scheduling of jobs is momentous to reduce production expenses and improve on time delivery by dec... more Scheduling of jobs is momentous to reduce production expenses and improve on time delivery by decreasing completion time of jobs. However, uncertain events in the real environment produce variations in the expected performance level of the deterministic schedules. In these circumstances, the risk of achieving substandard schedules' performance level than an expected one is an indispensable assessor for the efficiency of jobs schedule. To prevaricate the risk in two-machine flow-shop where make span is considered as a performance measure, a new heuristic method for robust scheduling is projected to minimize the risk of exceeding make span from a definite limit. The presented heuristic is experimented for scheduling of jobs in two-machine flow-shop of a manufacturing company in China. Result divulges that the proposed method specifies a schedule having maximum probability of attaining make span less than a threshold and the obtained schedule has minimum risk of exceeding make span...

Pakistan journal of pharmaceutical sciences, 2015

Bioassay guided fractionation of Cinnamon tamala leaf extracts yielded bornyl acetate (1), caryop... more Bioassay guided fractionation of Cinnamon tamala leaf extracts yielded bornyl acetate (1), caryophylene oxide (2), p-coumaric acid (3) and vanillic acid (4) using A-2780 human ovarian cancer cell lines. The structures of the isolated compounds were confirmed through spectroscopic techniques (EIMS, (1)H and (13)C NMR). Compound 1 exhibited highest cytotoxicity with 90.16 ± 1.06% inhibition (IC50=5.30 x 10(-4) mg/ml) followed by compound 2 (84.40±1.53% inhibition; IC50=8.94 x 10(-3)mg/ml), while compounds 3 and 4 were inactive in the bioassay.

Journal of Fluids Engineering, 2015

This investigation deals with some exact analytical solutions of the incompressible second grade ... more This investigation deals with some exact analytical solutions of the incompressible second grade fluid by using the method based on the separation of variables. In many cases, this method can derive exact analytical solutions easier than other methods. A family of solutions is derived in this paper, which governs scientific and engineering experimentations. The derived solutions represent the flows having streamlines as a family of ellipses, parabolas, concentric circles, and rectangular hyperbolas. From practical point of view, these flows have applications in many manufacturing processes in industry. Some physical features of the derived solutions are also illustrated by their contour plots.

Iranian journal of fuzzy systems

The solution of integro-di?erential equations have a major role in the fields of science and engi... more The solution of integro-di?erential equations have a major role in the fields of science and engineering. Different approaches both numerical and analytic are used to solve these type of equations. In this paper, the solution of fuzzy convolution Volterra integro-differential equation is investigated using fuzzy Laplace transform method under generalized Hukuhara diff?erentiability. Finally, the method is illustrated with few examples to show the ability of the proposed method.

In present study, the substrate kallar grass (Leptochloa fusca) was treated with alkali to explor... more In present study, the substrate kallar grass (Leptochloa fusca) was treated with alkali to explore its best possible use as a cheap substrate for bio-fuel production. In the beginning, physically processed kallar grass was soaked in various concentrations of NaOH (0.5% to 3%) for different soaking times (30min to 48h). The results showed that cellulose contents and delignification increased with the increase in concentration of alkali and soaking time. However, maximum cellulose content (40.17%) was observed with 2.5% NaOH after 24 h of soaking period. In physiochemical pretreatment, the substrate was soaked for 2h in alkaline solution having various concentrations (0.5 % to 3%) of NaOH and thereafter autoclaved at 121°C for 20 to 60min. Maximum cellulose content (58%) was achieved with 2.5% alkali solution at 121°C after 60 min while delignification was found 52%. All these results of the present study indicate that suitable concentration of alkali as well as autoclaving period at specific temperature is very much crucial to expose maximum cellulosic contents prior to employing kallar grass as a substrate for bio-fuel production.

Advanced Materials Research, 2012

Deep brain stimulation (DBS) is increasingly used in clinical treatment for various neurological ... more Deep brain stimulation (DBS) is increasingly used in clinical treatment for various neurological disorders, particularly for movement disorders such as Parkinsons disease. The more the accuracy of locating the cerebral target of these diseases is, the more cure effect is, the accuracy of locating the cerebral target depends on the all surgery system. Although there have many surgery systems, for more accuracy of those locating target based on CT images, it need to develop a new kind of robotic surgery system. Some requirements of this robotic system are present in this paper, such as the movement degrees of freedom and its dimension error. Each functional sub-system of this robotic surgery system with some constraint condition is also analyzed. When all of those sytem are implemented with more precise location, predictability, reliability, and robustness sufficient for trial evaluation in stereotactic biopsy of brain lesions, the robotic surgery system can be used in clinical applic...

2009 IEEE International Conference on Industrial Engineering and Engineering Management, 2009

Abstract - In order to improve on-time delivery of orders and reduce the delivery time of orders,... more Abstract - In order to improve on-time delivery of orders and reduce the delivery time of orders, the critical chain project management method is introduced to the order management in multi-variety and small batch order production companies and a critical chain based ...

SSRN Electronic Journal, 2012

ABSTRACT This is the first paper to look at the instance where a fired Chief Executive Officer (C... more ABSTRACT This is the first paper to look at the instance where a fired Chief Executive Officer (CEO) sues his former firm for breach of contract. Firms can fire their CEOs with cause in which case they do not have to pay severance to their former CEOs. We find that performance of these firms, as calculated by using accounting and market based measured, suffers immensely after the firing of the CEOs and the start of the litigation process. We find that the performance of these CEOs does not seem to warrant “termination with cause,” and market and judicial system seem to affirm this. In brief, the litigation process seems to have caused enough distraction to the new management to lead to poor long term performance for the firm. We also find that firms that fire their CEOs with cause are more likely to face litigation if worse performing peer firms fire their CEOs without cause (i.e. pay severance).

The Journal of Physical Chemistry B, 2011

Deuterium isotope effects measure the change in chemical shift on substitution of a proton by deu... more Deuterium isotope effects measure the change in chemical shift on substitution of a proton by deuterium. They have been calculated by direct treatment of the H/D nuclear quantum effect using a multicomponent ab initio molecular orbital method based on a non-Born-Oppenheimer approximation. This method enables the determination of both the electronic and the protonic (deuteronic) wave functions simultaneously and can directly calculate the geometrical difference induced by H/D isotope effects. The calculations show that the one-bond deuterium isotope effects on 15 N nuclear shielding, 1 Δ 15 N(D), in ammonium and amines decrease as a counterion or water molecule moves closer to the nitrogen. 1 Δ 15 N(D) and 2 Δ 1 H(D) of the NH 3 þ groups of lysine residues in the B1 domain of protein G have been calculated using truncated side chains and also determined experimentally by NMR. Comparisons show that the structures in solution are different from those in the crystal and that solvation plays an important role in weakening the hydrogen bonds. B dx.

Optics Communications, 2008

We demonstrate the possibility to stabilize the probability amplitude of the upper level for a si... more We demonstrate the possibility to stabilize the probability amplitude of the upper level for a single quantum two-level atom in a classical optical field with feedback control scheme.

Journal of the American Chemical Society, 2009

NMR investigations have been carried out on the B1 domain of protein G. This protein has six lysi... more NMR investigations have been carried out on the B1 domain of protein G. This protein has six lysine residues, of which three are consistently found to form surface-exposed salt bridges in crystal structures, while the other three are not. The N and H chemical shifts of all six lysines are similar and are not affected significantly by pH titration of the carboxylate groups in the protein, except for a relatively small titration of K39 N. Deuterium isotope effects on nitrogen and proton are of the size expected for a simple hydrated amine (a result supported by density functional theory calculations), and also do not titrate with the carboxylates. The line shapes of the J-coupled 15 N signals suggest rapid internal reorientation of all NH 3 + groups. pK a values have been measured for all charged side chains except Glu50 and do not show the perturbations expected for salt bridge formation, except that E35 has a Hill coefficient of 0.84. The main differential effect seen is that the lysines that are involved in salt bridges in the crystal display faster exchange of the amine protons with the solvent, an effect attributed to general base catalysis by the carboxylates. This explanation is supported by varying buffer composition, which demonstrates reduced electrostatic shielding at low concentration. In conclusion, the study demonstrates that the six surfaceexposed lysines in protein G are not involved in significant salt bridge interactions, even though such interactions are found consistently in crystal structures. However, the intrahelical E35-K39 (i,i+4) interaction is partially present.