Mehran University Research Journal of Engineering and Technology

4

Authors: Abbasi S.A., Syed U., Jhatial R.A.

This study was to analyze the mechanism of shear deformation and yarn slippage in the 3D (Three Dimensional) carbon woven fabric. For this study three weaves orthogonal, layer to layer and angle interlock were tested in Kawabata shearing instrument and all the results were analyzed. The relationship between the shear load and shear angle was measured in both warp and weft directions. It is shown that the fabric having highly compact structure exhibits high shear rigidity and it can withstand high shearing load. The orthogonal weave has shown much higher shear rigidity as compared to other weave structures

6

Authors: Khatri A., Arslan F., Jhatial R.A.

Textiles made of bamboo regenerated fibre are reported to have lower tensile strength than the other cellulosic fibres, due to high porosity of the fibre. This paper was aimed to modify the bamboo knitted fabric by the sol-gel coating to improve the tensile strength with minimum effect on its inherent morphology and ultimate relevant properties such as good absorbency and air permeability. The paddry- bake process was employed for the coating where tetraethyl-orthosilicate and nano-titanium-dioxide were used as the active ingredients. The treated fabrics were tested for the tensile behaviour in terms of breaking strength and elongation and the sol-gel process recipe and parameters were optimised. The absorbency, air-permeability and washing durability of the coating were also tested for the optimised process. Results showed the increase in tensile strength of the fabric by sol-gel coating, whereas absorbency and air-permeability were almost unaffected. The coating results were unaffected even after a washing treatment (equivalent to 5 industrial washings). Additionally, the wrinkle recovery angle of the coated fabric was also tested and found improved.

8

Authors: Shaikh S.A., Shaikh G.Y., Husssain T.

The study was undertaken to investigate the effects of pacing on aspects of performance at an assembly task and on the operators' responses related to work behaviour, perceived workload and perceived stress. A particular objective of the study was to investigate whether physical and cognitive demands may interact in their influences on these effects. An assembly task was simulated in the laboratory and the level of pacing imposed, work height and memory load within the task were all varied. The results showed that the type of pacing commonly imposed (as is common with a lean manufacturing Takt time system in industry) can significantly affect both performance and perceived workload and stress. Physical demands (through work height affecting posture) and mental demand (through memory load) were also found to have significant effects, as would be expected from the many studies of these in the literature. More importantly, some interactions were found between pacing and work height in their effects on quality of assembly and the operator's own rating of performance, and between work height and memory load in their effects on errors. These findings will need to be taken into account by companies when implementing Takt time systems.

8

Authors: Memon T.D., Halepoto I.A., Al-Otabi A.

Recently SWL (Short Word Length) DSP (Digital Signal Processing) applications has been proposed to overcome multiplier complexity that is evident in most of the digital applications. These SWL applications have been processed through sigma-delta modulation as a key element. For such applications, adder design plays vital role and can impact upon the chip area and its performance. In this paper, a ternary approach for adder tree has been proposed instead of binary that can accommodate more data with less chip-area at the cost of extra pin. The proposed ternary adder tree has been designed and developed in Quartus-II using three different design strategies namely T-gate (Ternary gate), LUT (Look Up Table) and algebraic equations. Through rigorous simulation it was found that T-gate technique results in superior performance, an average of 23.5 and 33% improvement compared to the same adder structure based on Boolean Algebraic Equation and LUT, respectively. The proposed adder design would benefit the efficient implementation of SWL applications.

8

Authors: Kumar W., Kumar P., Halepoto I.A.

The energy expenditure of cellular networks is increasing rapidly due to high demand of data services by the subscribers. This subsequently gives rise to the CO2 emission which is a critical issue nowadays. A hybrid cellular network comprised of macrocell and several femtocells is required to achieve reliability, continuous connectivity, and energy efficiency. To address the issue of energy efficiency, in this paper we present a queuing model of an energy efficient femtocell network. The transmission of data traffic in this type of network is modeled using M/M/1 queue where server FAP (Femtocell Access Point) takes vacation to save energy during inactivity period. The network model is solved using a MGM (Matrix Geometric Method). The performance of the system is evaluated in terms of average system delay and power savings for different sleep cycle durations. Results reveal that the maximum energy can be saved with higher sleep cycle duration at a cost of increased system delay

10

Authors: Mangrio W.B., Bhutto A., Naqvi I.B.

Several countries have adopted different strategies, models and policies to assist companies to develop their technological capabilities. These include high tech cluster development, creation of venture capital fund, establishment of technology incubation center, and Science & Technology parks. In turn, the creation of knowledge base industries, regional development, improves the technological infrastructure and life standard of the people. This paper discusses the contribution of science and technology parks in firms' performance in particularly employment, sales and profitability and also in creation of new businesses in information technology sector in Pakistan. This study is based on the case study of STPs (Software Technology Parks) of Islamabad. The results revealed that the establishment of STPs could be helpful in the creation of new companies as half of firms located at the STPs were startup enterprises. It helps firms to enhance its growth performance in the first five years after starting their business at these STPs. By developing software parks in three major cities, Pakistan Software Export Board have achieved partially its objectives.

10

Authors: Sahito A.R., Mahar R.B., Brohi K.M.

ABD (Anaerobic Biodegradability) and BMP (Biochemical Methane Potential) of banana plant waste, canola straw, cotton stalks, rice straw, sugarcane trash and wheat straw co-digested with buffalo dung was evaluated through AMPTS (Automatic Methane Potential Test System). The substrates were analyzed for moisture, TS (Total Solids) and VS (Volatile Solids), ultimate analysis (CHONS), pH and TA (Total Alkalinity). The BMPobserved during incubation of 30 days at the temperature of 37±0.2°C was 322 Nml CH4/g VSadd for wheat straw followed by 260, 170, 149, 142 and 138 Nml CH4/gVSadd for canola straw, rice straw, cotton stalks, banana plant waste and sugarcane trash respectively, whereas the maximum theoretical BMP was 481 Nml CH4/gVSadd for cotton stalks, followed by 473, 473, 446, 432 and 385 Nml CH4/gVSadd for wheat straw, banana plant waste, canola straw, rice straw and sugarcane trash respectively. The percentage ABD values were in the range of 68-30%. In addition to this, the effect of lignin content in the crop residue was evaluated on the ABD. The results of this study indicate that, the co-digestion of the crop residues with buffalo dung is feasible for production of renewable methane

12

Authors: Memon Mujeebuddin, Abbasi A.F., Daudpoto J.

Accurate prediction of fluid flow in the rotating cavity system is of practical interest as it is most commonly used in the gas turbine engines and compressors. This paper presents the numerical predictions of a rotating cavity flow system for Reynolds numbers of the range 1x105 < Re? < 4x105 and two different mass flow rates Cw=1092 and 2184. A finite-difference technique is employed for a Steady-state solution in the axisymmetric cylindrical polar coordinate frame of reference. The two low Reynolds number turbulence models, the low Reynolds number k-? model and the low Reynolds number second moment closure have been used to compute the basic characteristics of the flow inside the rotating cavity flow system. Different flow regions have been identified by computing flow structures and dimensions of those regions have also been studied under different flow rates. A comparison of the computed variation of moment coefficient of both the turbulence models are presented for the above mentioned parameters and the parametric effects on the moment coefficients have been discussed

12

Authors: Channa N., Lashar I.A.

The need of data and information is crucial to the human users. WWW (World Wide Web) plays a major role for fulfilling their needs, but sometimes all the purposes of human users are not achieved from the limited structure of the data available on the internet. However, the requirements of the accessibility of the data by users have also been changed and the same data is required in machine understandable form. IT (Information Technology) has become mandatory to convert the existing web from people-centric to software application-centric. The WS (Web Services) provide the suitable solution for application-to-application interoperability and integration over the Internet. WS is a promising technology that make available extensible and logical infrastructure for application to application communication constructed based on the current Web standards. The most accepted charm of the WS architecture is SOA (Service Oriented Architecture). The major roles involved in the WS infrastructure are service broker, service consumer/client and service provider. The technical pillars of WSs involve SOAP (Simple Object Access Protocol), WSDL (Web Service Description Language) and UDDI (Universal Description and Directory Service). By looking at the core pillars of the SOA triangle, we have investigated and explored all implementation aspects of the WSDL, SOAP and UDDI. We have further explored what UDDI is, structure of UDDI. How to create and publish WSDL into UDDI via SOAP, Operations of UDDI, how to access UDDI using java and SOAP clients. The extensive exploration of the work on UDDI implementation, help

12

Authors: Ali S., Ghani U., Arif S.

Flow resistance is a key factor in predicting the river conveyance capacity and associated water levels. In addition to bed resistance, the obstacles (embankments, spur dikes etc.) in the flood plain of a river contribute to the flow resistance. In particular the elevated parts are expected to play an important role. The objective of this study is to develop and parameterize an analytical model for the form drag due to such obstacles. An experimental study was carried out for validation purposes of the developed analytical model. The prototype weir-like structure (in the form of an embankment) was modeled as a weir with various leeside slopes. Measurements for energy head losses were carried out for a range of discharges and downstream water levels covering submerged flow conditions. The energy head loss due to submerged dikes was modeled as an expansion loss form drag. The analytical form drag model was estimated using a one-dimensional momentum conservation equation which accounts for the energy loss associated with a deceleration of the flow in the leeside region of the sudden expansion. The predicted losses from the analytical model agreed well with the experimental results. The minor deviations observed could be attributed to downstream slope effects and non- uniform velocity distribution in expansion zone (recirculation region) of an embankment.