Mehran University Research Journal of Engineering and Technology

6

Authors: Muhammad Khan Memon, Ubedullah Ansari, Habib U Zaman Memon

The residual oil after primary or secondary oil recovery can be recovered by the methods of EOR (Enhanced Oil Recovery). The objective of this study is screening the surfactants that generate maximum stable foam in the presence of brine salinity at 92oC. Laboratory experiments have been performed to examine and compare the stability of generated foam by individual and blended surfactants in the synthetic brine water. AOS C14-16 (Alpha Olefin Sulfonate) and SDS (Sodium Dodecyl Sulfonate) were selected as main surfactants. Aqueous stability test of AOS C14-16 and SDS with brine water salinity 62070ppm was performed at 92oC. AAS (Alcohol Alkoxy Sulfate) was blended with SDS and AOS C14-16. The solution was stable in the presence of brine salinity at same conditions. Salt tolerance experimental study revealed that AOS C14-16 did not produce precipitates at 92oC. Further, the foam stability of surfactant blend was performed. Result shows that, the maximum life time of generated foam was observed by using blend of 0.2wt% SDS+0.2wt% AOS+0.2wt% AS-1246 and 0.2wt% AOS+0.2wt% IOSC15-18+0.2wt% AAS surfactants as compared to the foam generated by individual surfactants. The success of generated foam by these surfactant solutions in the presence of brine water is the primary screening of surfactant stability and foamability for EOR applications in reservoirs type of reservoirs.

8

Authors: Shahid Amjad, Nuzhat Khan, Saira Ishaq

Biodiversity survey between Cape Monze and Churna Island was carried out for the assessment of coral assemblages in the area. During the present study, diving surveys were conducted to document the living corals that included deep sea coral, Coelenterates, Bryozoans, Gorgonia (Sea Fan), Scleractinian, (Stony Corals) Cnidaria (Hydroids), Porites (Small Polyp Stony), Pocilopora (Cauliflower Corals), Acropora (Hard Corals), sea urchins, sea anemones, coral fish spp, sea slugs, stone fish and bivalves were observed and documented. To have a better understanding of the distribution pattern “Shannon Weiner Biodiversity Index” for species diversity “H” (0.845-1.176) and evenness “J” (0.962-0.937) were calculated, the values indicate that the coral species were evenly distributed and did not show any significant variation in the area. Budding coral communities were observed at the sedimentary rock of Churna in patches, and showed a random distribution behavior all along the surveyed area. Random, scattered and aggregate distribution patterns of corals may be due to the wave beaten physical environment of Churna Island that do not allow sustainable growth of coral communities. Moreover, the high energy waves and water currents destablize and erode the sedimentary substrate on which corals grow. The corals are therefore unable to establish themselves to form a natural reef due to loss of natural living and non-living substrate. The ecology of Churna Island also under the influence of nearby coastal industries, and the Hub River influx causing floods in the SW monsoon period that may destablize rubble and increase the seawater turbidity level. These environmental factors contributing to the deterioration of present day corals, and larval settlement. It may be concluded that biological resources are renewable and can even increase with proper management techniques. Breakwater wall and artificial substrate must be encouraged to further facilitate the growth and development of Corals in the area.

9

Authors: Heman Das Lohano, Fateh Muhammad Marri

Water resources in Sindh province of Pakistan are under significant pressure due to increasing and conflicting water demand from municipalities for domestic users, agriculture and industries, and requirements of environmental flows. Population growth and climate change are likely to pose serious challenges to households and economic sectors that depend on water. This study estimates the present water demand from municipalities, agriculture and industries, and its future projections by the year 2050 in Sindh. The study also evaluates the impact of climate change on sectoral water demand and assesses the water requirements for the environmental flows. The results show that presently the total water demand for these sectors in Sindh is 44.06 Million Acre Feet (MAF). Agriculture is the largest consumer of water, accounting for 95.24 percent of the total water demand. Municipal water demand accounts for 2.61 percent while industrial water demand accounts for 1.88 percent. The demand for water in these sectors is expected to rise by 10 percent from 2018 to 2050. Moreover, depending on climate change scenario, the total water demand in these three sectors is likely to rise by 16 to 25 percent from 2018 to 2050. In additions, water requirements for the environmental flows have been indicated as 10 MAF in the National Water Accord of 1991. The findings of this study call for policy measures and strategies for management of water resources in Sindh.

10

Authors: Faheem Ali, Muhammad Naeem Arbab, Gulzar Ahmad, Majid Ashraf, Muhammad Sarim

Pakistan is faced with energy crises from the last two decades. Generation cannot balance the load demands of the electricity consumers. Power delivery systems are generally old-fashioned and overloaded. They are unable to provide consistent and uninterrupted supply to commercial, industrial, and domestic loads. Generally speaking, the Power Systems consist of loads that are inductive and resistive in nature. Heavy machinery, induction motors, and arc furnaces are heavily inductive in nature. Inductive loads when operated in a weak power system results in lagging VARs (Volt Ampere Reactive) and poor voltage regulation, which must be balanced by the same number of leading VARs in order to ensure unity power factor and thus helps in improving the voltage profile. At times the reactive VARs injected may not be sufficient to balance the VARs requires by the system, but still the power factor is improved up to some extent. In hot and humid climatic conditions, air-cooling system and chillers greatly burdens the grids. Such loads require excessive reactive VARs, and if not offered with ample reactive power, causes severe voltage drops in distribution system. To manage low voltages and power-factor, household users use automatic voltage regulators while industries connect capacitor banks. Voltage regulators control output voltage within the required limits at the expense of excessive line current from transformer, which may overburden it. Moreover, with each operation of tap changer, current rises which further intensifies line losses. Static capacitors provide stable voltage but repeated variations in load demands reliable and vigorous voltage regulation. This investigation aims to come up with a power quality improvement scheme which would deliver instantaneous control of power (reactive) with SVC (Static VAR Compensator) thus overcoming the shortcomings of step-wise banks of capacitors and or voltage regulators. Simulation work is carried out in MATLAB/SIMULINK and the results are compliance with IEEE Standards for SVCs. The device can offer steady state as well as dynamic VAR compensation under changing load conditions. Result showed considerable improvement both in terms of response time and power factor. Switching time has been improved to less than 1/10th fraction of a second which in previous simulations was 0.7 seconds approximately. Initial power factor without disturbance and without compensation was recorded to be 0.6 lagging, which after compensation was improved to 0.95 lagging. Similarly, in presence of disturbance without compensation the power factor fluctuated between 0.55 and 0.9 lagging, which after compensation was improved to 0.95 lagging and above throughout the course of operation.

10

Authors: Rahmatullah Shah, Muhammad Abid, Muhammad Farooq Qayyum

A field study was conducted to signify the use of sugarcane industrial and dairy farm wastes through composting and vermi-composting and application to tomato (Lycopersicum esculentum L) crop to evaluate any effects on growth, yield and fruit quality. Composts and vermi-composts of FM (Farm Manure), SB (Sugarcane Bagasse), SP (Sugarcane Pressmud), mixture of SB×SP×SE [sugarcane effluent (1:1:1)] @ 10 t ha1, respectively were applied before transplanting of nursery. The fertilizers NPK @ 81-76-76 kg ha-1 were also applied in all plots. Overall, there were significant (p≤0.05) impacts of treatments on agronomic and fruit quality traits. Plant height, stem diameter, number of leaves, number of fruits and yield were increased by 37, 67, 62, 59 and 24% with FMVC (Farm Manure Vermi-Compost) treatment over control. There was 6% increase in soluble solids of tomato fruit in FMVC plots compared with control treatment. However, maximum titrable acidity (0.0081mg citric acid/100g) in fruit juice was found in MVC plots. TN (Total Nitrogen) concentration of tomato fruit juice was increased by 1.74% in with FMVC over control treatments. Maximum lycopene contents (22.19 mg kg-1) were observed in FMVC plots as compared to all other treatments. It could be concluded that all treatments improved growth, yield and quality of fruit compared with control; whereas FMVC treatment performed better.

11

Authors: Nosheen Qamar, Ali Afzal Malik

Many different factors influence the quality of software. Among the most important of these factors is software complexity. One way to improve software quality, therefore, is to minimize its complexity making it more understandable and maintainable. The design phase of the software development life cycle plays an instrumental role in fostering quality in software. Seasoned designers often use past design best practices codified in the form of design patterns to make their designs and the resultant code more elegant, robust, and resilient to change. Little work, however, has been done to empirically assess the quantitative impact of design patterns on software complexity. This research is an attempt to fill this gap. A comparative analysis of before and after versions of program pairs written without and with design patterns was performed for all twenty three GoF (Gang of Four) design patterns. These program pairs were collected (or, in some cases, developed) and compared with respect to their complexity and size. The results of this comparative analysis reveal that the cyclomatic complexity of the programs written using design patterns was less for most of the design patterns as compared to the programs written without using design patterns. However, the values of CK metrics, number of classes, and software size SLOC (Source Lines of Code) increased when design patterns were used.

12

Authors: Muhammad Mateen Afzal Awan, Tahir Mahmood

Modern-day world is facing problems such as, electricity generation deficiency, mounting energy demand, GHG (Greenhouse Gas) emissions, reliability and soaring prices. To resolve these issues, sustainable and renewable energy resources like SPV (Solar Photovoltaic) would be quite helpful. In this regard, the extraction of maximum power from SPV array in PSC (Partial Shading Weather Conditions) remains a challenge. Creation of multiple power peaks in the P-V (Power-Voltage) curve of a PV array due to partial shading, makes it difficult to track GMPP (Global Maximum Power Point) out of multiple power peaks known as LMPP (Local Maximum Power Points). Conventional algorithms are not able to perform in any condition other than UWC (Uniform Weather Condition). Nature inspired SC (Soft Computing) algorithms efficiently track the GMPP in PSC. The top performing SC algorithm named, FPA (Flower Pollination Algorithm) presents an efficient solution for GMPP tracking in PSCs. In this paper, the efficiency, accuracy and tracking speed of FPA algorithm is optimized. Comparison of the proposed OFPA (Optimized Flower Pollination Algorithm) and the existing FPAs is performed for zero shading condition, weak PSC, strong PSC, and changing weather conditions. In zero shading conditions, improvement of 0.7% in efficiency and 33% in tracking speed is achieved. In weak shading conditions, improvement of 0.97% in efficiency and 32.2% in tracking speed is achieved. In strong shading conditions, improvement of 0.24% in efficiency and 30.6% in tracking speed is achieved. OFPA is also tested for changing weather conditions (entering from Case-1 to Cae-3) and it retains its outstanding performance in the changing weather conditions. Simulations are performed in MATLAB/Simulink.

14

Authors: Muhammad Sulaiman, Muhammad Sulaman, Abdelwahed Hamdi, Zubair Hussain Hussain

In modern and large scale power distribution topologies, directional relays play an important role in the operation of an electrical system. These relays must be coordinated optimally so that their overall operating time is reduced to a minimum. They are sensor protection devices for the power systems and must be coordinated properly. The present work uses a metaheuristic optimization technique known as the Plant Propagation Algorithm (PPA) in order to suggest improved solutions for the optimization problem of coordination of directional overcurrent relays (DOCRs). We have obtained comparatively better solutions for the overall operating times taken by relays fitted on important positions in the system. Our findings are useful in isolating the faulty lines efficiently and in keeping the continuity of power supply. The difference in response times taken in coordination between primary relays and corresponding backup relays is minimized. The output of our experiments is compared with various algorithms and classical optimization techniques, which are found in the literature. Moreover, graphical analyses are presented for each problem to further clarify the results.

18

Authors: Faria Kanwal, Mariam Rehman, Malik Muhammad Asif

With the rapid growth of ICT (Information and Communication Technologies), the traditional educational system has been restructured into e-learning systems. E-learning adoption and acceptance is in rudimentary stages of development in Pakistan. Therefore, it is imperative to understand and evaluate the critical factors of technology adoption and acceptance considering the moderating effect of individual differences (gender and experience) based on Technology Acceptance Model. Quantitative analysis was conducted on 356 learners from the Virtual University of Pakistan. Structural Equation Modelling was used to test research models. The results illustrate that the perception of and intention to adopt technology are highly dependent on gender and experience in using e-learning systems. Computer anxiety and social influence are significant predictors of elearning adoption in female learners whereas social influence and enjoyment is significant predictors in less experienced learners than more experienced learners.

23

Authors: Saeed Ullah Jan, Fawad Qayum, Ajab Khan

The SIP (Session Initiation Protocol) is an application and presentation layer signaling protocol used for initiating, continuing and terminating multimedia session for the end user. It gains much attention of the researchers because it is exposed to several threats and noticed challenging vulnerabilities from time to time. Consequently, the security of SIP is a crucial task and many efforts have been made by different researchers and tried to divert the attention towards its solution. But still, no one claims with conviction about a foolproof secure mechanism for SIP. As users extensively use SIP services, the mutual authentication and key agreement among the participants is an important issue. So, robust authentication and key agreement scheme are mandatory for enhancing security, legitimacy and better complexities. Therefore, we present an improved three-factor authentication scheme that caters all the weakness and known attacks in Mishra et al. scheme. The proposed scheme not only guarantees for security but performance can also be made lightweight. As performance and security contradict each other, the change in one inversely affects the other. The proposed scheme has been analyzed both formally using BAN (Burrows-Abadi-Needham) logic and ProVerif1.93 software verification toolkit, and informally using assumptions which show a delicate balance of security with performance.