Sharif Digital Repository

Regarding complexity and wide range use of distribution network structures, loss reduction is possible in case of complete knowledge and suitable approaches. Loss reduction not only can grow GDP but also can improve economic growth. It should have schedule and plan wisely. Thus, in this research, first a region called Yusef Abad in Tehran was selected then the network was assessed completely. During the assessment, the research team determines causes of energy loss and load loss and then measured amount of each one. Then, the loss share of each element of the network determined. Elements of the network consist of transformers, conductors and meters. Then possible solutions for loss reduction... 

The twin-entry radial inflow gas turbine is extensively used in engine turbochargers. The use of twin-entry radial flow turbine in the turbocharging systems makes it possible to use the kinetic energy of pulsating exhaust gases. This turbine is usually exposed to partial admission conditions in engine operating conditions, which the flows in each inlet are not equal for most of the time. This partial admission varies from zero flow in one entry with full admission in the other, to full flow in both entries. The flow pattern in this turbine is complex and three dimensional due to geometry and inlet conditions. Therefore, better understanding of the flow pattern and losses in the turbine can... 

This research investigates the role and effects of knowledge management processes in reducing both cost and waste at the Dorsa Leather Goods Company. This methodology is based on both qualitative and quantitative research methods. The qualitative stage consists of analysis of past research and interviews with all levels of management. This stage leads to identifying knowledge management factors, effective in reducing cost and waste. Subsequently, we identified five main aspects encompassing all the effective aforementioned factors. These aspects are strategic, organizational structure, human resource, organizational culture, and technological infrastructure.The quantitative stage is... 

The need for independent power generation has been increased in recent years with the growing demand in micro grid systems. Losses in power systems are unavoidable. These losses occur in transmission to distributionnetworks from the generation sites to the end-user loads. Reduction of power losses has been one of the reasons for engineers to be attracted by micro grid systems which include small size independent power generation units. However, in a micro grid with several DGs of different types and with all kinds of loads of variable nature, an optimal power balance in the system has to be achieved. This optimal objective, which results in minimal energy losses over a specific period of... 

In this research numerical and experimental study of a twin entry radial inflow gas turbine is performed. At first, various models of energy losses are investigated and compared and the most comprehensive combination of these models are selected. Using conservation equations, gas dynamics relations and energy loss models, the one dimensional model of radial inflow turbine is developed.One-dimensional modeling has lower computing cost in compare with two and three- dimensional models, while gives reliable results, Hence it would be the preferred option for turbine preliminary performance prediction. In this study the one dimensional model based on a step by step procedure, for each turbine... 

As electric energy loss in Iran is around 31 percent and 01 percent of this loss is related to the distribution of electric energy, management and operation of distribution network is of high importance. There are different ways for operating the distribution network while decreasing the loss, such as using capacitors, tap changers, energy storing devices, distributed generations, etc. One of the most common ways is to use Network Reconfiguration. In this thesis, daily reconfiguration of a 03-kV 22-bus distribution network is investigated. The objective function consists of cost of energy loss and improvement of voltage profile. Wind turbines are used as the sources of distributed generation... 

Many studies on hybrid vehicles have been done in the past few years. The Full hybrid vehicles need a large number of batteries creating up to 300V to meet the required voltage of electric motor. The size and weight of the batteries cause some problems. This research investigates the mild hybrid vehicle. This vehicle includes a small electric motor and a high power internal combustion engine. In most cases the car’s driving force is created by internal combustion part. A small electric motor, which can operate as engine starter, generator and traction motor, is located between the engine and automatically shifted multi-gear transmission (gearbox). The clutch is used to disconnect the gearbox... 

The demand for independent power generation has been increased in recent years due to the growing demand in distributed networks, losses and power qaulity in power systems. These losses occur in transmission to distribution networks from the generation sites to the end-user loads which have harmonic losses besides fundamental losses.. The non-linear load makes the harmonics flow in the line and create the harmonic losses. However, in a distributed network with several DGs of different types and with all kinds of variable nature loads, an optimal power balance in the system has to be achieved. This optimal objective, which results in minimal energy losses over a specific period of time,... 

The purpose of the present study is to plan an industrial system, over a period of 10 years, so that over time, while supplying the required demand, to optimal resource utilization with regard to material reuse and recovery flows of losses as well as the use of renewable resources move to implement the concept of a circular economy. One of the main incentives for the transition to a circular economy is carbon tax policy, which has been taken into account. The results of the decision-making model based on cost and flow constraints indicate that the use of carbon dioxide as a by-product of Pars Petrochemical Extraction Unit in order to produce urea in Pardis petrochemical industry in addition... 

Losses are unavoidable in any parts of power systems, from generation to receiving nodes and occur in transmission and distribution networks. However, the main loss component is produced in distribution networks. Energy losses in distribution networks are about 70% of technological transport energy losses.
Energy losses in distribution networks are an important indicator for the planning and operation of the system. A fast, reliable and accurate energy loss calculation method is required for optimal operation of the distribution networks.
Energy loss depends on network's operating conditions. Loads values and loads factors are time variables; therefore, methods based on probability... 

Overpressure protection and flare loading network are critical challenges faced by the Oil & Gas and chemical industries. Whether they are new facilities or aging ones, integrity management of overpressure and flaring systems remain significant throughout the life of the planet. One of the most important ways for protection of over pressure and depressurizing to flare header through pressure safety valve is implementation of safety instrument system (SIS). Application of safety instrumented systems for the process industries causes significant reduction of flaring load and loss prevention of valuable materials through increase protection layer availability and over pressure risk reduction.... 

In electrification networks, a considerable percentage of electrical energy generated in power plant is dissipated through the path from generation to consumption, most of which is in electric power distribution, approximately 18%. The amount of these losses depends on several factors such as distribution networks structure, kind of apparatus, load density, kind of consumption, consumption curve, climatic conditions, due to diversity and variety of these factors, power losses differ even for two apparently similar electric power distribution . Power distribution companies in Iran decrease power losses since a few years ago, but in practice, because of different parameters and indexes, which...