Effects of Board of Directors on Firm Performance: A Study on KSE Firms

This paper investigates the impact of number of independent directors, split role of independent directors, board meeting and female directors on firm performance in KSE. The study measure the ROA on firm performance. Because agency theory suggests that companies with better corporate governance standards perform better. The study proposes that better governed KSE firms would have greater performance and higher valuation. The study finds that our composite measure of corporate governance is positively and significantly associated with firm performance and valuation. These findings have implications for policy makers, researchers, managers, and investors in general and those in emerging markets in particular. Keywords: Independent directors, split role, board meeting, female directors, RO

Unusual Electron Transfer Rate Effects due to Pyridyl Ring Substituents and Trace Group VIII b Hexacyano Complexes as Added Salts

The rates of pseudo-self-exchange electron transfer reactions between [(NH3)5RuIIL]2+ and [(NH3)5RuIIIL’]3+ at reactant concentrations of 1.0 х 10-4 M (where L, L’ = substituted pyridines) and the reaction between [(NH3)5RuIIPy]2+ and [(NH3)5RuIII3FPy]2+ at different reactant concentrations in the presence of various salts added were studied by using the stopped-flow kinetic spectroscopy. Marcus theory rate vs. driving force plots yielded distinct families of lines depending on whether a 3- or 4- phenylpyridine ligand was present, and reactions of 4-phenylpyridine were in all cases the fastest. Both temperature dependent studies (stopped-flow and dynamic NMR measurements) indicate that the origin of the phenyl substituent effect is in the enthalpic portion of the free-energy of activation. One explanation is that the reorganizational barrier λ might be significantly lower for the 3-Phpy and 4-Phpy complexes, or it could be that energetically-favorable p-p stacking interactions (known to be common in compounds bearing the phenyl rings) may be helping to enhance bimolecular precursor complex formation. Salt effect studies showed that the apparent catalytic activity of the salts muconate, terephthalate and 1,4-DCCH decreased modestly as the reactant ion concentrations were increased. In agreement with prior NMR work (Yinshin,Q.;2011) we found that the superexchange ET catalysis by trace MII(CN)6-4 varied strongly in the order Ru \u3c Os \u3c F

Optimization of hydraulic fracturing in tight gas reservoirs with alternative fluid

Due to the finite nature of petroleum resources and depletion of conventional reservoirs, the exploitation of unconventional resources has been a key to meeting world energy needs. Natural gas, a cleaner fossil fuel compared to oil and coal, has an increasing role in the energy mix. It is expected that the peak global natural gas production will remain between 3.7-6.1 trillion m3 per year between 2019 and 2060. Therefore, addressing the technical challenges posed by reservoir exploitation technologies in an environmentally responsible manner is critical for efficient energy production and energy secure of the world. Hydraulic stimulation is the first means of choice for improving productivity from tight gas reservoirs by creating highly conductive flow paths with the injection of high-pressure fluid. Millions of hydraulic fracture operations have been performed with water-based fluid which have caused environmental concerns such as water availability and ground water quality degradation due to surface handling and flowback water disposal. Moreover, in lower permeability gas reservoirs, the support agents (proppants) settle at the bottom of fracture due to delayed fracture closure, and slow flowback and water blockage cause hindrance to natural gas flow leading to inefficient fracturing operation. The solution is to replace existing water-based frac-fluids with alternative frac-fluids. Therefore, fracturing with light n-alkanes consisting of pentane, hexane, heptane, octane, nonane and decane is proposed. A single component fluid, or a mixture of components in different proportions can be designed according to reservoir conditions. The characteristics of hydrocarbon nature and significantly lower density and viscosity compared to water can help achieve the objectives of quick fracture closure for better proppant placement, expeditious flowback and reduced phase trapping. Thus, in addition to creating better conductivity fractures, environmental issues associated with water-based fluids can be minimized. To perform hydraulic fracturing with the alternative fluid, a multiphase multicomponent simulator for hydraulic fracturing and fluid flow in fracture and matrix based on popular thermo-hydro-mechanical (THM) FLAC3D-TOUGH2MP/TMVOC framework is utilized. After verification, the model is applied to case study of LPG application in a tight gas reservoir of Canada for hydraulic fracturing operation. Simulations with different frac-fluids such as water, propane and n-heptane have been performed and their fracturing performance including the proppant settling behavior have been compared. The application of proposed alternative fluid for hydraulic fracturing optimization of wellbore yx1 in a tight gas reservoir of Germany showed that fractures with better conductivity in consideration of boreholefracture connection can be created. Sensitivity analysis through numerous simulations for parameters such as injection rate, fluid viscosity and permeability were performed. The flowback analysis demonstrated that most of the injected alternative frac-fluid can be recovered within one week of fracturing which results in better clean up and early start of natural gas production. The fracture permeability and conductivity are dependent upon proppants. Conventionally, spherical proppants have been utilized, however, rod-shaped proppants offer higher porosity and permeability compared with spherical proppants. To analyze their performance, a production model for proppants with different shapes and sizes is implemented in FLAC3D-TMVOCMP framework. The simulations for production forecast with spherical and rod-shaped proppant fractures have been performed considering mechanical properties contrast between proppant and formation under the influence of closure stress with developed model. The application of model to wellbore yx1 showed that 7% more recovery can be achieved from aspect ratio 1 rod-shaped proppant compared to same diameter spherical proppant over a period of ten years. Based upon this work, proposed alternative fluid and rod-shaped proppants are recommended for efficient stimulation of tight gas reservoirs

BALLOON TRAWL; A SAFE AND EFFECTVE WAY OF REMOVING COMMON BILE DUCT (CBD) EMBEDDED STENTS

Biliary stenting has been used since the 1970s to relieve biliary obstruction for a variety of causes including benign and malignant biliary strictures. Migration of stents proximally into the biliary tree or distally into the intestinal tract is relatively uncommon. We report a case of a 64-year-old female with a peri-ampullary tumour, who had symptomatic obstructive jaundice following endoscopic retrograde cholangiopancreatography and plastic stent insertion. Follow-up imaging showed proximal migration of the plastic stent and blockage of the distal common bile duct (CBD) secondary to the periampullary tumour. The biliary stent was safely removed endoscopically using balloon trawl. This case highlights that, while biliary stenting for strictures is generally safe and effective, stent migration to proximal CBD can occur. Balloon trawl is safe and effective way of removing such stents. Key words: Biliary stricture, common bile duct, endoscopic retrograde cholangiopancreatography, periampullary tumour, stents

Hydraulics design and simulation of new kind of leg

Rolking leg is the phenomena which represent those legs which has the capability of rolling as well as walking. The importance of this kind of leg is that it removes the drawbacks which are present in both rolling and walking kinds of leg phenomena. Rolk-ing leg is not only smooth but also can move with some good speed from different kind of terrain. Rolking leg with electric actuators is already been researched in Helsinki, but they are not for carrying load. That is the one goal given by General Intelligent Ma-chines (GIM) to Department of Intelligent Hydraulics and Automation (IHA) to have such hydraulic actuated leg which can carry heavy load. In this master thesis goal is to choose the hydraulic components which are necessary for the rolking leg. Implementation of hydraulic system in order to carry the heavy load cannot be denied, because the electrical actuator can work upto some extent but they are not long term solution. Selection of hydraulic cylinders and valves came into existence according to the need of leg and the weight it has to carry. After selection of components, simulation of designed rolking leg has been made and control system to lift and lower the leg in Matlab. A rough terrain has been given to leg through which it has to pass and leg frame stability has been monitored as well behavior of hydraulic system to gain the stability. All the results shown with having quite reasonable behavior of selected hydraulic com-ponents as well as the stability of rolking leg frame

Prevalence of Poor Sleep and Relationship of Physical Exercise with Sleep among Male Adult Exercisers

Physical exercise has been suggested to show beneficial effects for various diseases and also for sleep. This study aims to assess the prevalence of sleep problems, and the relationship of physical exercise with sleep health among adult male exercisers. A total of 199 randomly selected athletes (all males) took part in this study. All participants responded to a questionnaire consisted of items related to demographic information that also included sports participation level, and playing experience. Self-reported sleep quality and physical exercise were using PQSI and three items concerning exercise frequency, intensity, and duration. The analysis revealed following main findings: 1) a significant negative correlation between physical exercise and sleep medication, 2) a significantly negative relationship between sports/ exercise participation level and sleep disturbance, 3) an 3.7 average global score of PSQI in total sample, 4) Exercise frequency was negatively correlated with daytime dysfunction whereas exercise intensity was negatively correlated with sleep disturbance and sleep efficiency but positively correlated with daytime dysfunction, 5) and prevalence of poor sleep in 22 % participants. There is some possibility to suggest that exercise may improve sleep health among adult male exercisers. The increased exercise frequency more positive impact to improve sleep but the relationship between exercise intensity and sleep remains inconclusive. existence of sleep problems in athletic population essentially require further attention for reducing the prevalence of poor sleep using other approaches along with continue doing exercise for good sleep

DRIVERS OF ENERGY INTENSITY IN PAKISTAN: AN ASSESSMENT USING INDEX DECOMPOSITION METHODS

We employ index decomposition techniques to decomposeaggregate energy consumption into energy intensity, efficiency andstructural change indices for Pakistan. Data suggests that energyinefficiencies play a prominent role in increasing energy intensitywhile structural changes cause small reduction in intensity index.Partial adjustment model was applied to investigate underlying forcesof energy intensity and its components. Results illustrate that energyprices and capital-labor ratio have significant effect in reducing energyintensity through efficiency channel whereas; income predominantlyincreases energy intensity through inefficient energy use. Extensivepolicy intervention is required through implementing energy intensityreduction targets for efficient energy use