UET Peshawar Publications Site (University of Engineering and Technology, Peshawar)
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EXTRACTION OF HIGH QUALITY TALC FROM TALC-CARBONATE ROCK OF MINGORA EMERALD MINES BY FLOTATION AND LEACHING
No full textTalc is hydrated magnesium silicate with chemical formula Mg3Si4O10(OH)2. In natural form pure talc is an extreme rarity and it is mostly associated with undesired minerals like magnesite, calcite, dolomite, quartz, muscovite, hlorite,tremolite and iron bearing minerals. These associated minerals determine the quality of talc for industrial purpose and if in access, limits its applications. In present research work, beneficiation studies of carbonatic talcose rock of Mingora emerald mine located in District Swat, Khyber Pakhtunkhwa (KP), Pakistan were conducted to recover high quality talc out of the talc carbonate rock and to develop a technique for up gradation of indigenous non-commercial talc resources from other locations. These rocks host emerald crystals and the debris are dumped after excavation and extraction of emerald crystals. Controll of environmental threat caused by these rock dumps is an additional benefit of the research. Two step froth flotation process with AF65 (Poly propylene Glycol, Cyanamid) as frother, Sodium hexa metaphosphate as depressant for carbonates, equal mixture of oleic acid and kerosene oil as collector gave encouraging results. It was found that talc can be separated as float at pH 6 - 7±0.2 in rougher flotation and 10 - 11±0.2 in cleaning flotation, depressant dosage 0.10kg/ton, and collector dosage of 1.2 kg/ton. Talc concentrate at recovery of about 60 - 70% with a grade of 92.50% from an ore containing about 50 to 70% talc was obtained. The final concentrate was treated with various leaching reagents. Dilute HCl (30%) + stannous chloride (300 ppm) gave better results. It reduced iron content from 4.37% in the concentrate to 2.89% in the final leached product and whiteness also improved up to 80% from about 51% of original talcose rock. Some tests were also conducted to improve whiteness of leached products but with little improvement in results
SEISMIC CAPACITY OF RETROFITTED LOW-STRENGTH CONCRETE BRIDGE PIERS
No full textThis paper presents seismic performance of two large size models using low strength concrete (LSC). A study after October 2005 earthquake in Pakistan revealed that bridges damaged were categorized using Low Strength Concrete (LSC) due to various reasons. The tests for subject evaluation were carried out on 1:4 scaled models of LSC circular bridge pier under a physical load of 3015.7 kN (678 kips). These models were subjected to cyclic lateral loads and free vibration tests to determine changes in dynamic properties of the system for variation in loading and drift levels. The models were first tested in their original state till their failures resulting in damages at the potential plastic zones, thereafter the damaged columns were repaired and confined with Carbon Fiber Reinforced Polymer (CFRP) and tested for their recovery of strength and ductility. A comparison of the test results of the models in both original and retrofitted conditions has indicated that even the damaged columns after CFRF retrofit can be made to recover their original strength and improved ductility to withstand even larger potential earthquakes
A COMPREHENSIVE PRODUCTION ORIENTED TECHNIQUE FOR CELLULAR MANUFACTURING SYSTEM DESIGN
No full textThe current manufacturing environment is consistently posing enormous challenges to the manufacturing firms in the form of unpredictability in customer demands and ever decreasing product life cycles. To meet these challenges the manufacturing firms are required to perform even more effectively. Cellular Manufacturing (CM), a philosophy of group technology, possesses the ability to produce variety of products like job shop and at a comparatively faster rate like flow line. Therefore CM can help in facing these challenges. Though CM is very beneficial, its design for real life applications is very complex. Most of the techniques developed to design Cellular Manufacturing Systems (CMS) have considered it as a part-machine grouping problem only and overlooked the important production related information, such as demand of products, process details and the system availability. Therefore, this paper aims at developing a comprehensive design approach for CMS that takes in to account most of these production related information while designing the system. This approach simultaneously assigns parts and machines to suitable cells in such a way that no intercellular movement occurs and the work load of each cell is also balanced
DYNAMICS OF URBAN SPATIAL GROWTH AND PLANNING: A CASE STUDY OF PESHAWAR
No full textThis paper traces the growth of Peshawar, one of the major cities of Pakistan. Data and information for the study was collected from historic maps, documents and satellite images. The analysis shows that the city has been growing at a very rapid pace in recent years and in the absence of planning control has seen tremendous urban sprawl. The pattern of development of urban sprawl in Peshawar is typical of most Pakistani major cities, where ribbon sprawl is common along major roads, while leapfrog sprawl is prevalent in the city’s fringes. The uncontrolled expansion in the built up area is typically consuming rich agricultural land and pose a threat to food security. The study highlighting the causes of urban sprawl, discusses some of the strategic and policy options that are available to control their proliferation for sustainable development of the city in future
NUMERICAL SIMULATION OF MEANDERING OPEN CHANNEL FLOWS
No full textFlooding occurs worldwide and causes huge loss to human life and property. There is an ever increasing danger of floods due to global warming. The overbank flow studies are important for understanding flow behavior and bed shear stresses during floods and for devising flood protection strategies. This study is based on three dimensional numerical simulation of overbank flows in meandering channels. Four different flow cases were considered. The cases vary from each other in the sense of bed slope and overbank flow depth. There were two overbank flow depths for each bed slope. In this study a rectangular main channel flanked by floodplains on both sides has been considered. The simulation was carried out by solving 3D continuity and Reynolds averaged Navior Stokes equations using a finite volume based numerical code. The turbulence closure was achieved through standard - turbulence model. A comparison of simulated primary depth averaged velocities and conveyance capacities of main channel with experimental results were made and good agreement was achieved. The simulations were also made for stream-wise velocities and secondary velocity vectors over different sections along the meander wavelength for the four cases to enhance the understanding of the primary and secondary flow fields and boundary shear stresses using numerical simulation. It was observed that the direction of secondary currents depends upon flow depth and their strength increases with increasing depth of flow. In compound channel flow cases, the overbank flow velocities are stronger than the inbank flow field. The bed shearing stresses at the apex of the meander were also found to have been under the influence of flow depth and secondary circulations. It was also established that standard - turbulence model which is incapable of simulating straight channels flows can simulate meandering channels to good accuracy
CONSIDERING ENVIRONMENTAL FLOW FOR WATER RESOURCES MANAGEMENT IN SOUTH ASIA: CURRENT STATUS AND CHALLENGES
No full textEnvironmental flow (EF) indicates, in general, the minimum required flow to maintain the valued features of a river system. The concept of EF is central to achieving sustainable water resources management. Adopting the EF at a river basin scale however, poses a great challenge and is observed still at its infancy. An attempt is, therefore, made to reflect the implication and need of the EF in sustainable water resources management including the challenges most likely the water professionals face in adopting the EF. This paper further reviews the current status of the adoption and use of the EF approach in water resources management, in particular for the South Asian countries where freshwater is becoming scarce, leading to an environmental water scarcity. The review finds modest progress in assessment and adoption of EF into water resources management in Sri Lanka, Pakistan and India; however, Bangladesh and Nepal show an early stage progressing. Towards the end a few recommendations have been put forward on the measures required in recognizing the EF as an effective tool in integrated water resource management
HARDWARE IMPLEMENTATION OF H .264/AVC DEBLOCKING FILTER
No full textThis paper describes the design and hardware implementation of deblocking filter for reduction of blocking artifacts in latest video compression standard H.264/AVC (Advance Video Coding). H.264/AVC deblocking employ two types of filters: strongest filter and normal filter. The strongest filter utilizes maximum resources. In this paper, strongest filter of H.264/AVC is implemented on FPGA (Field Programmable Gate Array). The proposed architecture has the ability of computing the results of luminance and chrominance in fewer cycles which speeds up the filtering process. Moreover, throughput is enhanced by the use of 16 8-bit memory blocks. The proposed architecture of the filter is first implemented in MATLAB and then coded using HDL (Hardware Description Language) verilog. The proposed architecture achieves 96 clock cycles per macroblock utilizing 23K gate count, critical path delay of 9.790nsec, maximum frequency of 332MHz, and minimum frequency of 42MHz
STATUS OF PERFORMANCE MEASUREMENT SYSTEMS IN INFRASTRUCTURE CONSTRUCTION FIRMS OF PAKISTAN
No full textConstruction sector, even in developed countries, is criticized for sub-optimal performance. The situation is no different in case of Pakistan construction industry. Being regarded as an answer to challenges framed by globalized competitive environment, performance measurement discipline has received much attention among researchers and construction firms during last two decades. Before a solution in the form of a suitable performance measurement framework could be prescribed to domestic firms to solve performance related problems, it is a pre-condition that one gets to know the health of performance measurement system (PMS) currently practised by these organizations. Questionnaire based survey revealed that there is an empirical evidence that most of the infrastructure firms find their PMS in need of urgent attention while one third of the surveyed firms consider their system needs improvement. Analysis of the results points out that current PMSs ignore the performance information needs of critical stakeholders like employees, customers and suppliers. Further the system design is marred by short-termism and less attention is paid to non-financial performance drivers necessary for achieving long term goals
SYNTHESIS OF A NOVEL ROBUST INTELLIGENT CASCADED REACTIVITY CONTROLLER FOR CANDU REACTOR
No full textIn this paper, a Novel Intelligent Cascaded Reactivity Controller (NICRC) is synthesized for a CANadian Deuterium Uranium (CANDU) -type Nuclear Power Plant (NPP) operating in Pakistan. The designed NICRC is a cascaded configuration of reactor power and moderator level controllers composed of five sub-controllers. The proposed NICRC is designed using intelligent soft computing technique. The original reactivity controller of CANDU nuclear power plant is a networked controller implemented on a Programmable Logic Controller (PLC). The new NICRC is designed based on two Intelligent Distributed Cascaded Power Controller (IDCPC) and Intelligent Cascaded Moderator Level Controller (ICMLC) for moderator level control in CANDU reactor core. The IDCPC is composed of three neural sub-controllers while ICMLC is composed of two neural sub-controllers. The proposed NICRC is designed using Adaptive Back Propagation Feedforward Neural Network (ABPFNN). The proposed controller is synthesized in a distributed parallel computing environment using MATLAB. The proposed NICRC is formulated in a highly complex multi-objective neural form and evaluated against full power operation of CANDU nuclear power plant from cold start-up to high power. The performance of highly robust NICRC is tested and evaluated for a typical transient providing complete coverage of moderator level, low log and steam pressure modes of CANDU reactor and found excellent within the desired control bands.  
AN ANALYSIS OF COMMUNICATION ARCHITECTURES FOR VARIOUS AVAILABLE MULTI-CORE SYSTEMS
No full textModern sophisticated multimedia-like applications are extremely useful, but require hardware platforms that can provide high computational power. Conventional single core systems were capable of handling computationally expensive applications up to a certain extent, but increased clock frequencies resulted in high power consumption. Thus the need for multi-core based systems was realized. The overall performance of such systems depends not only on the individual processor cores but also on the underlying communication network between them. This paper presents an analysis of communication architecture for various available multi-core systems