Seepage Problems and Remedies – Hub Dam

On the first impounding of Hub Dam, seepage problems started. The foundation piezometers showed rising pressures. The areas of concern were limestone, bed rock, jointed sandstone and gravel deposits at overburden-rock contact. Observational approach was followed. It was decided to fill the reservoir in stages. Various alternatives were considered to control the underseepage pressures. Relief Wells were installed which proved effective and economical to control the problem. A gravel shell was added on the downstream slope to enhance the stability of the homogeneous section in case of seepage through the body of the dam

Innovative configurable and collaborative approach to automation systems engineering for automotive powertrain assembly

Presently the automotive industry is facing enormous pressure due to global competition and ever changing legislative, economic and customer demands. Both, agility and reconfiguration are widely recognised as important attributes for manufacturing systems to satisfy the needs of competitive global markets. To facilitate and accommodate unforeseen business changes within the automotive industry, a new proactive methodology is urgently required for the design, build, assembly and reconfiguration of automation systems. There is also need for the promotion of new technologies and engineering methods to enable true engineering concurrency between product and process development. Virtual construction and testing of new automation systems prior to build is now identified as a crucial requirement to enable system verification and to allow the investigation of design alternatives prior to building and testing physical systems. The main focus of this research was to design and develop reconfigurable assembly systems within the powertrain sector of the automotive industry by capturing and modelling relevant business and engineering processes. This research has proposed and developed a more process-efficient and robust automation system design, build and implementation approach via new engineering services and a standard library of reusable mechanisms. Existing research at Loughborough had created the basic technology for a component based approach to automation. However, no research had been previously undertaken on the application of this approach in a user engineering and business context. The objective of this research was therefore to utilise this prototype method and associated engineering tools and to devise novel business and engineering processes to enable the component-based approach to be applied in industry. This new approach has been named Configurable and Collaborative Automation Systems (CO AS). In particular this new research has studied the implications of migration to a COAS approach in terms of I) necessary changes to the end-users business processes, 2) potential to improve the robustness of the resultant system and 3) potential for improved efficiency and greater collaboration across the supply chain... cont'

Product to process lifecycle management in assembly automation systems

Presently, the automotive industry is facing enormous pressure due to global competition and ever changing legislative, economic and customer demands. Product and process development in the automotive manufacturing industry is a challenging task for many reasons. Current product life cycle management (PLM) systems tend to be product-focussed. Though, information about processes and resources are there but mostly linked to the product. Process is an important aspect, especially in assembly automation systems that link products to their manufacturing resources. This paper presents a process-centric approach to improve PLM systems in large-scale manufacturing companies, especially in the powertrain sector of the automotive industry. The idea is to integrate the information related to key engineering chains i.e. products, processes and resources based upon PLM philosophy and shift the trend of product-focussed lifecycle management to process-focussed lifecycle management, the outcome of which is the Product, Process and Resource Lifecycle Management not PLM only

CHARCTERIZATION OF TUBE WELL IRRIGATION WATER AND ASSOCIATED SOILS IN THE SALT AFFECTED AREA OF DISTRICT MARDAN

ABSTRACT A study was conducted to characterize tube well irrigation waters and associated soils in the salt affected area of district Mardan during Rabi 2004Rabi -2005 season. Samples of the tube wells/dugwells waters and associated soils were collected and analyzed in the laboratory. All the water samples were alkaline with residual sodium carbonate (RSC) values more than 2.5. Sixty percent of the sites had water with sodium adsorption ratio (SAR) values greater than 10. Fifty percent samples had moderate to severe salinity. Soils irrigated with the respective tube well waters showed problems of sodicity. Soil electrical conductivity (EC e ) and soil solution Na + showed positive response to the EC and Na + of tube wells' water (r = 0.817 ** and 0.871 ** respectively). Ionic concentration of irrigation water had significant relation with that of soils suggesting that most of the salts were deposited through the continuous use of tube-well waters. Soils of all the sites were alkaline in reaction, highly calcareous and low in organic matter. Tube well waters of all the sites had limited utility for irrigation due to high RSC and SAR. Management practices like application of amendments, growing salt tolerant crops and provision of supplemental irrigation of canal waters need due consideration in the study area for judicious use of this mentioned resource

Hydraulic Fracture Conductivity in Shale Reservoirs

Optimum conductivity is essential for hydraulic fracturing due to its significant role in maintaining productivity. Hydraulic fracture networks with required fracture conductivities are decisive for the cost-effective production from unconventional shale reservoirs. Fracture conductivity reduces significantly in shale formations due to the high embedment of proppants. In this research, the mechanical properties of shale samples from Sungai Perlis beds, Terengganu, Malaysia, have been used for computational contact analysis of proppant between fracture surfaces. The finite element code in ANSYS is used to simulate the formation/proppant contact-impact behavior in the fracture surface. In the numerical analysis, a material property of proppant and formation characteristics is introduced based on experimental investigation. The influences of formation load and resulted deformation of formation are calculated by total penetration of proppant. It has been found that the formation stresses on both sides of fractured result in high penetration of proppant in the fracture surfaces, although proppant remains un-deformed

Neural network-based adaptive global sliding mode MPPT controller design for stand-alone photovoltaic systems

The increasing energy demand and the target to reduce environmental pollution make it essential to use efficient and environment-friendly renewable energy systems. One of these systems is the Photovoltaic (PV) system which generates energy subject to variation in environmental conditions such as temperature and solar radiations. In the presence of these variations, it is necessary to extract the maximum power via the maximum power point tracking (MPPT) controller. This paper presents a nonlinear generalized global sliding mode controller (GGSMC) to harvest maximum power from a PV array using a DC-DC buck-boost converter. A feed-forward neural network (FFNN) is used to provide a reference voltage. A GGSMC is designed to track the FFNN generated reference subject to varying temperature and sunlight. The proposed control strategy, along with a modified sliding mode control, eliminates the reaching phase so that the sliding mode exists throughout the time. The system response observes no chattering and harmonic distortions. Finally, the simulation results using MATLAB/Simulink environment demonstrate the effectiveness, accuracy, and rapid tracking of the proposed control strategy. The results are compared with standard results of the nonlinear backstepping controller under abrupt changes in environmental conditions for further validation

Product to process lifecycle management in assembly automation systems

Presently, the automotive industry is facing enormous pressure due to global competition and ever changing legislative, economic and customer demands. Product and process development in the automotive manufacturing industry is a challenging task for many reasons. Current product life cycle management (PLM) systems tend to be product-focussed. Though, information about processes and resources are there but mostly linked to the product. Process is an important aspect, especially in assembly automation systems that link products to their manufacturing resources. This paper presents a process-centric approach to improve PLM systems in large-scale manufacturing companies, especially in the powertrain sector of the automotive industry. The idea is to integrate the information related to key engineering chains i.e. products, processes and resources based upon PLM philosophy and shift the trend of product-focussed lifecycle management to process-focussed lifecycle management, the outcome of which is the Product, Process and Resource Lifecycle Management not PLM only

Cytotoxicity, In vitro anti-Leishmanial and fingerprint HPLC- photodiode array analysis of the roots of Trillium govanianum.

Trillium govanianum Wall. ex D. Don (Melanthiaceae alt. Trilliaceae), commonly known as 'nagchhatry' or 'teen patra', distributed from Pakistan to Bhutan about 2500-3800 m altitude is indigenous to Himalayas region. In folk medicine the plant has been reported for the treatment of wound healing, sepsis and in various sexual disorders. This paper reports, for the first time, to evaluate the cytotoxicity, in vitro anti-leishmanial (promastigotes) and fingerprint HPLC-photodiode array analysis of the MeOH extract of the roots of T. govanianum and its solid phase extraction fractions. Reverse phase HPLC-PDA based quantification revealed the presence of significant amount of quercetin, myrecetin and kaemferol ranging from 0.221to 0.528 μg/mg DW. MeOH extract revealed distinguishable protein kinase inhibitory activity against Streptomyces 85E strain with 18 mm bald phenotype. The remarkable toxicity profile against brine shrimps and leishmanial was manifested by MeOH extract with LC50 10 and 38.5 μg/mL, respectively

A hydraulic analysis of shock wave generation mechanism on flat spillway chutes through physical modeling

Shock waves are generated downstream of spillways during flood operations, which have adverse effects on spillway operations. This paper presents the physical model study of shock waves at the Mohmand Dam Spillway project, Pakistan. In this study, hydraulic analysis of shock waves was carried out to investigate its generation mechanism. Different experiments were performed to analyze the rooster tail on a flat spillway chute and to examine the factors affecting the characteristics of the rooster tail. The study results show that shock wave height is influenced by spillway chute slope, pier shape, and flow depth. Moreover, the height of the shock wave can be minimized by installing a semi-elliptical pier on the tail part of the main pier. Further modifications in the geometry of the extended tail part of the pier are recommended for the elimination of the shock wave. Based on observed data collected from the model study, an empirical equation was developed to estimate the shock wave height generated on the flat slope spillway chutes (5◦ to 10◦ )