Mehran University Research Journal of Engineering and Technology

7

Authors: Shahid Hussain Abro

It is common practice that formation of second phase particles such as nitrides or carbides in the steel matrix has significant role to control the grain size of steel. An attempt is made in the present research work to find out the role of nitrogen to form the nitride particles either with Al, Ti, B, Cr or Si. Two steel samples Steel-A and Steel-B with same titanium and aluminum weight percent in the chemical composition were obtained in hot rolled conditions from international market with only the difference of presence of Niobium in Steel-A. Solution heat treatment was performed at 1350°C with 60 minutes holding time in protherm heat treatment furnace available locally was used to dissolve the particles and then steel samples were reheat treated at 800°C with holding time of 60 minutes and water quenched and microstructure was revealed. Transmission electron microscope connected with Ehlers-Danlos Syndrome (EDS) was used to reveal the morphology of second phase particles. Both samples for a high resolution power Transmission Electron Microscopy (TEM) (Jeol JEM 3010) analysis were prepared by using carbon extraction replica method in 5% Nital solution as an etching technique. Both samples were then caught in copper grid of 3mm for using TEM analysis. TEM micrographs clearly revealed the second phase particles in the matrix of steel. The EDS peaks were studied and it was found that the peaks showed the titanium peaks in both the samples A and B and surprisingly there was no any peak found for aluminum. Stoichiometric calculations were carried out and it was found that weight percent nitrogen required for forming TiN is 0.0073, however the total nitrogen present in both the steels A and B is 0.0058 and 0.0061 respectively. That means that all the nitrogen present in the steel matrix was consumed by titanium to form the Titanium Nitride (TiN) so there was no nitrogen remain to fulfil the requirement of aluminum to form the Aluminum Nitride (AlN) particles.

8

Authors: Sardar Jehangir; Sohail Khan; Sulaiman Khan; Shah Nazir,; Anwar Hussain

This paper presents an efficient Optical Character Recognition (OCR) system for offline isolated Pashto characters recognition. Developing an OCR system for handwritten character recognition is a challenging task because of the handwritten characters vary both in shape and in style and most of the time the handwritten characters also vary among the individuals. The identification of the inscribed Pashto letters becomes even palling due to the unavailability of a standard handwritten Pashto characters database. For experimental and simulation purposes a handwritten Pashto characters database is developed by collecting handwritten samples from the students of the university on A4 sized page. These collected samples are then scanned, stemmed and preprocessed to form a medium sized database that encompasses 14784 handwritten Pashto character images (336 distinguishing handwritten samples for each 44 characters in Pashto script). Furthermore, the Zernike moments are considered as a feature extractor tool for the proposed OCR system to extract features of each individual character. Linear Discriminant Analysis (LDA) is followed as a recognition tool for the proposed recognition system based on the calculated features map using Zernike moments. Applicability of the proposed system is tested by validating it with 10-fold cross-validation method and an overall accuracy of 63.71% is obtained for the handwritten Pashto isolated characters using the proposed OCR system.

9

Authors: Irshad Hussain; Faizullah Khan; Ishtiaq Ahmad; Surat Khan; Muhammad Saeed

The energy demand all over the world is increasing rapidly day by day. In traditional power systems, power plants are located far away from the consumer’s premises. This in turn causes a substantial amount of power loss both in transmission and distribution. In general, distribution system has more losses than the losses occurred on the transmission side. It employs that there will be a significant difference between the generated power and the energy consumers that are (physically) far away from the generating stations. Therefore, the electric utilities always remain under stress due to such non negligible amount of losses which has a direct impact on financial management and efficiency of the power system as well. To address this issue different technique have been introduced to reduce line losses and to improve the efficiency. The best among these techniques is line loss reduction through Distributed Generation (DG) which is more effective than the other techniques. In this paper we have taken three 11kV feeders (located at Bannu) as a case study and for the prescribed technique an attempt has been made to increase the efficiency of a system by integrating different capacity of DG into a radial distribution feeder. The results have been analyzed mathematically, however Electrical Transient Analyzer Program (ETAP) simulator is used as a test bed. Finally, the obtained results are presented in tabular and graphical form in terms of clearly defined parameters.

10

Authors: Attiya Baqai; Maria Jan; Rafay Rasheed Maher

Learning through play has always proved its effectiveness in elementary education and has yielded prolific results. Although there are trained instructors, special schools, specific toys and facilities for Visually Impaired (VI), yet the communication between tutors and special children holds a significant gap. Also, tools in market are either too expensive or available in limited quantity in underdeveloped countries. This paper presents a cost effective solution for visually impaired children to play and learn via Braille blocks. These blocks are designed by embossed motives representing numbers, alphabets, shapes and mathematical operators with Infra-Red (IR) tags. The blocks transmit Infrared codes when come in contact with the system. The Braille Blocks System consists of a battery, optical detectors and controller which performs detection and processing of selected IR pattern. This system comprises of three different learning modules namely Words Game, Shapes Game and Math Game. These modules are further divided into several sub-game sections so that the children can learn and improve their communication and academic skills. The presence of audio feedback elevates a child’s capabilities to memorize and concentrate on self-learning and spatial coordination in a fascinating way. The designed system was tested on 20 blind children in “National Special Education Complex” Karachi, Pakistan and an assessment was conducted on basis of different types of errors encountered by children. The suitability of the system was also evaluated by taking feedback from blind students through a questionnaire, proving its effectiveness with 79% of blind children giving either good or very good feedback.

11

Authors: Abdul Majeed Shar, Aftab Ahmad Mahesar, Asad Ali Narejo, Noor Fatima

Pakistan has been suffering from severe energy crisis for decades. Discovering new oil and gas fields plays significant role in alleviating the energy deficit. Exploitation and development of new fields for the country is very challenging due to economic, technological, social and environmental concerns. Hence, it is essential to assess the potential of hydrocarbon bearing formations using integrated analysis techniques in order to explore the resources efficiently. In this paper, we have analyzed Nari sandstone reservoir potential of the country. The key objectives of the study are to characterize petrographic, mineralogical and microstructural data through laboratory study on Oligocene strata of Nari sandstone in the lower Indus Basin. For this purpose, we collected several exposed outcrop samples from different stations in the onshore areas of Nari Sandstone formation. The work performed includes, the integrated study of petrography using Scanning Electron Microscopy (SEM) along with Energy Dispersive Spectrometry (EDS) application. In addition, Quantitative X-Ray Diffraction (QXRD) analysis was performed. The results revealed that these sandstones were mainly composed of quartz grains, which are surrounded by calcite cement. EDS elemental sequence shows Calcium (Ca), Carbon (C), Silicon (Si), Iron (Fe), Magnesium (Mg), Aluminum (AI) and K (Potassium) in variable intensities in the samples indicating the presence of different minerals within these rocks such as quartz, calcite, clay and ferruginous cement. This study is the comprehensive collection of data of Nari sandstones that is essential to assess the potential of hydrocarbon bearing formations.

11

Authors: Faisal Saleem; Ahsan Ali; Inam ul Hasan Shaikh; Muhammad Wasim

This paper investigates the trajectory tracking problem for a Multi-Input Multi-Output (MIMO) Twin Rotor Aerodynamic System (TRAS) using a hybrid architecture based on an H∞ controller and Iterative Learning Control (ILC). TRAS is a fast, nonlinear coupled system and therefore it is a challenging task to design a control system that ensures the tracking for fast changing trajectories. The controllers proposed in the literature for the TRAS through linear approaches tend to have a large control effort, while the ones designed using the nonlinear approaches track only for smooth input trajectories. Both issues are important from control point of view. In this paper, these issues are addressed by designing a feedback H∞ control that stabilizes the system and a feedforward ILC which reduces the control effort. The H∞ controller achieves the tracking for input trajectories with sharp edges, but the control effort required for tracking is large. With the proposed hybrid approach, tracking is achieved by the H∞ controller whereas the required control effort is reduced in each subsequent iteration by ILC. After a few iterations, accurate tracking at a minimized control effort is achieved. The simulations have been performed using MATLAB software and the controller designed through the proposed approach has been validated on nonlinear model of the system. The results of the proposed technique, compared with the flatness-based and back-stepping control strategies, show that the proposed controller ensures accurate tracking at the reduced control effort.

12

Authors: Ghulam Hussain Dars, Mehran Sattar, Muhammad Tauseef, Courtenay Strong, Muhammad Raza Najafi

Water resources managers and policy-makers need reliable projections of hydro-climatic conditions to develop sound water management policies. Global Climate Models (GCMs) are the primary basis for projecting how the climate may change over the coming decades. However, GCMs have low spatial resolution and inherent biases that limit their direct utility for understanding localized climate change impacts. These limitations are particularly pronounced in mountainous areas, where the terrain exhibits variations at scales much finer than the GCM grid spacing. The main goal of this study is to downscale precipitation and mean temperature simulations from an ensemble of 10 GCMs that participated in the Coupled Model Intercomparison Project Phase-5 (CMIP5) under two Representative Concentration Pathways – RCP4.5 and RCP8.5. The simulations were bias corrected using quantile mapping and downscaled to a 30 arc second spatial resolution (approximately 1 km) through using the delta method over the Indus River Basin and Pakistan for 2040-2070. The GCM processing was carried out using the Global Climate Data (GCD) package. The results show that for all seasons and most of the Indus River Basin (IRB) and Pakistan, future precipitation will be highly uncertain except UIB wherein mean annual precipitation is projected to increase by 8% under RCP 4.5 and 14% under RCP 8.5. However, the models are highly confident about increase in the temperature for this region. Relative to the baseline period (1960-1990), the annual mean temperature in the IRB is projected to increase by 2°C under RCP 4.5 and 2.6°C under RCP 8.5 for 2040-2070.

13

Authors: Muhammad Azeem; Junaid Alam Memon; Fateh Muhammad Mari

Environmental and anthropogenic changes in lakes have implications for fishers’ livelihoods in form of their forced migration and occupational change. Those advocating lake restorations often face a dilemma when asked if lake restoration will also restore the lost livelihoods. Answering such questions are difficult because most people are not programmed for frequent changes in their livelihood structures. Using the case study of Manchar Lake fishers who seemingly have faced such transition, this study brings insights on this broad question. We developed an in-person survey based on Contingent Valuation Method (CVM) to study 300 fishers’ responses to a hypothetical situation whereby they were asked to “Switch Back” to Manchar Lake assuming that it has been restored to provide various ecosystem services. Results show that complete transformation in the livelihoods of fishing communities has taken place with remarkable variation in their access to assets and livelihood outcomes. Despite increase in their access to physical capital such as school, hospital, roads, and markets, the communities are still vulnerable to income shocks and rarely enjoy privileges such as house ownership. The comparative state of current and past livelihoods and asset possessions determine ones’ willingness to switch back to fishing in Manchar Lake. Those who may have performed better in the said transition are less likely to return to their erstwhile occupations even if the lake is restored and vice-versa. We conclude that satisfaction with current livelihood outcomes is low and willingness to switch back to fishing in Manchar Lake is high since many had been poor performers in the transition. While the environmental rationale for the Manchar Lake’s ecological restoration already exists, this study suggests that there also exists a socioeconomic rationale albeit in a way that restoration also supports contemporary ecological services such as tourism.

15

Authors: Syed Haseeb Sultan; Arkom Palamanit; Kua-Anan Techato; Muhammad Amin; Khurshid Ahmed Baloch

Bioenergy has gained great interest in the recent years for being environmentally friendly and renewable energy resource. Southern Thailand is well-known for agro-industry including rubber tree plantations and processing, which provide biomass that could be applied to produce bioenergy. Thus, this study aimed to investigate the energy potential of Rubber Wood Chips (RWC), Rubber Wood Pellets (RWP), Unburned Char (UBC) from rubber wood, blended RWC:UBC (50:50%) and blended RWP:UBC (50:50%). The physiochemical properties including bulk density, proximate composition, ultimate composition, heating value, Thermogravimetric Analysis (TGA), and lignocellulose content were determined for the biomass samples. The thermochemical conversion of biomass to syngas was performed using a downdraft gasifier operated at equivalence ratio 0.3. The results showed that the biomass was rich in carbon (content ranging from 44.77 to 58.54%) making it suitable for use as a solid fuel for gasification or combustion. The moisture contents of the biomass samples were below 10%. The contents of volatile matter in RWC and RWP were 74.40 and 75.40%, respectively. The UBC had a high fixed carbon content (50.60%) and comparatively low volatile matter (19%). The bulk densities of RWC, RWP and UBC were 193, 555 and 177 (kg/m3 ), respectively. The TGA showed the maximum weight loss of RWC and RWP around 400 °C, but this was at 800 °C for UBC. The higher heating values of RWC, RWP and UBC were 17.8 MJ/kg, 17.4 MJ/kg and 19.3 MJ/kg, respectively. The RWC and RWP had high cellulose and hemicellulose contents while UBC was rich in lignin. The syngas obtained from any of these biomass samples was mainly CO (10.81-22.67%) and CH4 (0.06-3.16%) with the lower heating value ranging from 2.78 to 4.72 MJ/Nm3 . These results indicate that rubber wood biomass in various forms has relatively high potential for bioenergy applications via gasification, and it can help to support the renewable energy sector in Thailand.

15

Authors: Abid Imtiaz; Adnan Tariq; Ajaz Bashir Janjua; Fahad Sarfraz; Amar ul Hassan Khawaja

Friction Stir Welding (FSW) is a solid-state joining process for metals, non-metals and polymers. It is carried out with the help of a specially designed, non-consumable tool. The heat required, for creating a softened region at the faying surfaces, is generated by rotation of tool against the work piece material. Being a solid-state welding process, it offers several advantages like inducing minimum effect on the mechanical properties of base material, reduced shrinkage and distortion, no spatter or Ultra Violet (UV) radiations etc. However, developing a sound weld requires an appropriate combination of several process parameters e.g. the design of tool, its rotational and traversing speeds etc. To substantiate this aspect, an approach based on Response Surface Methodology (RSM) is presented during this paper that optimizes the combination of process parameters while investigating their effect on the mechanical properties of a friction stir welded butt joint configuration of Polycarbonate. To minimize the total number of combinations a Central Composite Rotatable Design (CCRD) is used with three factors and two levels. The results have shown that the butt joints fabricated at a traverse speed of 14 mm/min, rotational speed of 1700 RPM and with simple cylindrical conical tool geometry yielded the maximum ultimate tensile strength of 51.299 MPa.

25

Authors: Hasham Khan

The rapid increase in the population and fastest development in the industrial sector has increased the energy demand throughout the world. Frequent outages and load shedding has seriously deteriorated the efficiency of the electrical power distribution system. Under such circumstances, the implementation of Distributed Generation (DG) is increasing. Small hydel generators are considered as the most-clean and economical for generating electrical energy. These are very complex nonlinear generators which usually exhibits low frequency electromechanical oscillations due to insufficient damping caused by severe operating conditions. These DGs are not connected to the utility in many cases because, under varying load, they cannot maintain the frequency to the permissible value. This work presents detailed analysis of operating characteristics and proposes a hybrid frequency control strategy of the small hydel systems. The simulation and testing is performed in MATLAB, the results verified the improved performance with the recommended method. The proposed method conserves half of the power consumption. The control scheme regulates the dump load by connecting and disconnecting it affectively. The application of presented methodology is convenient in the deregulated environment, especially under the severe shortage of energy. The proposed model keeps the frequency of system at desired level. It reduces the noise, thereby improving the response time of the designed controller as compared to conventional controllers. The innovative scheme also provides power for small scale industrial, agricultural and other domestic application of far-off areas where the supply of utility main grid is difficult to provide. The recommended scheme is environmental friendly and easy to implement wherever small hydel resources are available.