General Electric

The objective of this paper is to model and optimise solar organic rankine cycle (ORC) engines for reverse osmosis (RO) desalination using currently available solar thermal collectors. The proposed systems are intended to be potentially attractive for remote areas without (or with very high cost) access to the public electricity grid.

Proton exchange membrane fuel cell 1-Butyl-3-methylimidazolium chloride 1-Butyl-3-methylimidazolium tetrafluoroborate a b s t r a c t Proton exchange membrane fuel cells (PEMFCs) are used in portable devices to generate electrical energy; however, the efficiency of the PEMFC is currently only 40%. This study demonstrates that the efficiency of a PEMFC can be increased to 61% when 1-butyl-3-methylimidazolium tetrafluoroborate (BMI.BF 4 ) ionic liquid (IL) is used together with the membrane electrode assembly (MEA). The results for ionic liquids (ILs) 1-butyl-3-methylimidazolium chloride (BMI.Cl) and 1-butyl-3-methylimidazolium tetrafluoroborate (BMI.BF 4 ) in aqueous solutions are better than those obtained with pure water. The current and the power densities with IL are at least 50 times higher than those obtained for the PEMFC wetted with pure water. This increase in PEMFC performance can greatly facilitate the use of renewable energy sources.

This paper is a review of the texture development in zirconium alloys (in the form of thick walled tube reduced extrusion or TREX, thin-walled tubing and sheets) of importance to light and heavy water nuclear reactor technology along with the resultant anisotropic mechanical properties. Quantitative characterization of texture and mechanical anisotropy are emphasized leading to procedures useful to fabricators in optimizing textures for good formability as well as for acceptable in-service performance. A brief history of the development of zirconium alloys is presented followed by texture development and characterization. Mechanical anisotropy is discussed in terms of transverse contractile strain ratios from which the formability (B parameter) is derived. Results on the effect of annealing temperature as well as test temperature on anisotropy parameters are presented. The review concludes with a brief summary of texture effects on creep, stress corrosion cracking and hydride formation. Recent advances in fuel cladding bring out the challenges in characterizing the texture and anisotropy due to Nb additions and microstructural gradients in the new Zircaloyse , 1 such as Zirloe , 2 , Duplexe , 3 and Triclad e , 4 .

Environmental aspects of using supercritical water oxidation (SCWO) to treat sewage sludge were studied using a life cycle assessment (LCA) methodology. The system studied is the first commercial scale SCWO plant for sewage sludge in the world, treating sludge from the municipal wastewater treatment facility in Harlingen, TX, USA. The environmental impacts were evaluated using three specific environmental attributes: global warming potential (GWP), photo-oxidant creation potential (POCP) and resource depletion; as well as two single point indicators: EPS2000 and EcoIndicator99. The LCA results show that for the described process, gas-fired preheating of the sludge is the major contributor to environmental impacts, and emissions from generating electricity for pumping and for oxygen production are also important. Overall, SCWO processing of undigested sewage sludge is an environmentally attractive technology, particularly when heat is recovered from the process. Energy-conserving measures and recovery of excess oxygen from the SCWO process should be considered for improving the sustainability potential.

This paper explores wind power integration issues for the South Australian (SA) region of the Australian National Electricity Market (NEM) by assessing the interaction of regional wind generation, electricity demand and spot prices over 2 recent years of market operation. SA's wind energy penetration has recently surpassed 20% and it has only a limited interconnection with other regions of the NEM. As such, it represents an interesting example of high wind penetration in a gross wholesale pool market electricity industry. Our findings suggest that while electricity demand continues to have the greatest influence on spot prices in SA, wind generation levels have become a significant secondary influence, and there is an inverse relationship between wind generation and price. No clear relationship between wind generation and demand has been identified although some periods of extremely high demand may coincide with lower wind generation. Periods of high wind output are associated with generally lower market prices, and also appear to contribute to extreme negative price events. The results highlight the importance of electricity market and renewable policy design in facilitating economically efficient high wind penetrations.

In Nicaragua, two sugar mills are going to generate electricity from eucalyptus outside the sugarcane season. The eucalyptus comes from the sugar mills' already existing industrial energy plantations. In this study, we look at the possibility of an alternative wood supply from small scale farm-based plantations to one of these sugar mills. With farm-based plantations 77% of the value added which is generated eventually beneÿts low income groups, while with the industrial plantations this is between 17 and 47%. Employment creation doubles when the wood is produced by farmers instead of the sugar mill. If the wood is sold as standing stock, the farmers would need at least a price of 6:7 $=m 3 in order to obtain the minimum wage of 2:2 $=day invested in the plantation. The avoided costs for the sugar mill are almost 11 $=m 3 . With the already existing sale of wood to the urban market, the farmers can obtain a net income of 4:9 $=day. If they would sell their wood to the sugar mill and if the sugar mill is willing to pay the avoided costs, this will become 5:5 $=day. Overall, from a ÿnancial point of view, there seems to be a good opportunity for Nicaraguan farmers to produce wood for electricity generation in sugar mills.

This paper focuses on a Life Cycle Assessment (LCA) of four waste management strategies: landfill without biogas utilization; landfill with biogas combustion to generate electricity; sorting plant which splits the inorganic waste fraction (used to produce electricity via Refuse Derived Fuels, RDF) from the organic waste fraction (used to produce biogas via anaerobic digestion); direct incineration of waste. These scenarios are applied to the waste amount and composition of the Municipality of Roma (Italy) and are evaluated under different points of view: global and local emissions, total material demands, total energy requirements and ecological footprints. Results, reliable for most of the European big cities, show landfill systems as the worst waste management options and significant environmental savings at global scale are achieved from undertaking energy recycling. Furthermore, waste treatments finalized to energy recovery provide an energy output that, in the best case, is able to meet the 15% of Roma electricity consumption.

We investigate the properties of correlation based networks originating from economic complex systems, such as the network of stocks traded at the New York Stock Exchange (NYSE). The weaker links (low correlation) of the system are found to contribute to the overall connectivity of the network significantly more than the strong links (high correlation). We find that nodes connected through strong links form well defined communities. These communities are clustered together in more complex ways compared to the widely used classification according to the economic activity. We find that some companies, such as General Electric (GE), Coca Cola (KO), and others, can be involved in different communities. The communities are found to be quite stable over time. Similar results were obtained by investigating markets completely different in size and properties, such as the Athens Stock Exchange (ASE). The present method may be also useful for other networks generated through correlations.

Environmental concerns coupled with the depletion of fuel sources has led to research on ethanol, fuel cells, and even generating electricity from vibrations. Much of the research in these areas is stalling due to expensive or environmentally contaminating processes, however recent breakthroughs in materials and production has created a surge in research on waste heat energy harvesting devices. The thermoelectric generators (TEGs) used in waste heat energy harvesting are governed by the Thermoelectric, or Seebeck, effect, generating electricity from a temperature gradient. Some research to date has featured platforms such as heavy duty diesel trucks, model airplanes, and automobiles, attempting to either eliminate heavy batteries or the alternator. A motorcycle is another platform that possesses some very promising characteristics for waste heat energy harvesting, mainly because the exhaust pipes are exposed to significant amounts of air flow. A 1995 Kawasaki Ninja 250R was used for these trials. The module used in these experiments, the Melcor HT3-12-30, produced an average of 0.4694 W from an average temperature gradient of 48.73 • C. The mathematical model created from the Thermoelectric effect equation and the mean Seebeck coefficient displayed by the module produced an average error from the experimental data of 1.75%. Although the module proved insufficient to practically eliminate the alternator on a standard motorcycle, the temperature data gathered as well as the examination of a simple, yet accurate, model represent significant steps in the process of creating a TEG capable of doing so.

This paper describes the development of a small-scale system designed to generate electricity from low temperature heat (e.g., solar energy). The system operates on the Rankine cycle and uses n-pentane as the working¯uid. A prototype system has been designed, constructed and tested. It is capable of delivering 1.5 kW of electricity with a thermal eciency of 4.3%. Laboratory test results and a cost estimate for the prototype unit are presented in the paper. 7

Planarians are the simplest animals to exhibit a body plan common to all vertebrates and many invertebrates, characterized by bilateral rather than radial symmetry, dorsal and ventral surfaces, and a rostrocaudal axis with a head and a tail, including specialized sense organs and an aggregate of nerve cells in the head. Neurons in planarian more closely resemble those of vertebrates than those of advanced invertebrates, exhibiting typical vertebrate features of multipolar shape, dendritic spines with synaptic boutons, a single axon, expression of vertebrate-like neural proteins, and relatively low spontaneously generated electrical activity. Here we report the most relevant contribution to the knowledge of the neuropharmacology of planarians, with particular reference to the behavioral consequences of the exposure to drugs acting on neural transmission. Neurochemical and histochemical data indicate the presence of several neurotransmitter-receptor systems in planarians. Moreover, a variety of experimental studies characterized specific behavioral patterns of these animals following the exposure to drugs acting on neural transmission. There is also evidence of the interactions between discrete neurotransmitter-receptor systems in modulating behavior in planarians. Finally, the model has proved efficacy for investigating the neurotoxicology of the dopamine neurons, and for the initial screening of the neuroprotective potential of drugs. In conclusion, these findings indicate that interactions between discrete neurotransmitter-receptor systems occur very early along phylogeny, although they may have evolved from very fundamental behaviors, such as motor activity in planarian, to more complex and integrated functions in vertebrates.

Region growing is a very useful technique for image segmentation. Its efficiency mainly depends on its aggregation criterion. In the present paper, a new algorithm is proposed with a homogeneity criterion based on an adequate tuning between spatial neighbourhood and histogram neighbourhood. It differs from other techniques by reconsidering the pixel (or voxel) assignments on each step by a process which minimizes variance through special dilations. Thus, the region created by an initial seed can be non-connected and possibly does not contain this seed. Examples are given in dental surgery for 2D X-Ray images (and their associated 3D block) and for 3D images acquired by the Morphometre, the new 3D scanner constructed by GEMSE (General Electric Medical Systems). © 1997 Published by Elsevier Science B.V.

The quality of generated electricity in power systems is dependent on the system output, which has to be of constant frequency and must maintain the scheduled power and voltage. Therefore, load frequency control, LFC, is very important for power systems. However, the LFC problem in hydroelectrical power systems has received little attention by researchers so far. In this study, a conventional proportional integral (PI) controller and a fuzzy gain scheduled proportional integral (FGPI) controller have been compared for applying to a single area and a two area hydroelectric power plant, considering that Turkey has several hydro power sources. The comparison study indicated that the proposed FGPI controller has better performance than the conventional PI controller. The study results were compared by simulation.

Industrial gas-turbine engine had many developments in the past 60 years and becomes the common power plant. Egypt, middle east and Africa is considered one of the biggest region for gas turbine markets. The main aim of the present project is to submit a preliminary design for gas turbine. This is to improve engine performance in the world markets. Engine developments in gas-turbine design have endeavors of larger net-power, low noise and emission as well as better fuel economy. These goals were achieved by increasing of the compressor pressure ratio (PR), turbine inlet temperature (TIT) as well as using modifications of gas-turbine cycle and cooling techniques for both turbines and combustion chamber. Such modifications led to improvements in cycle efficiency, decreases in specific fuel consumption (SFC) and increase the net power. This paper presents a parametric study and design point selection of a heavy duty industrial gas-turbine engine (close to GE-F9). This engine is one of the products of GE Aviation Company. Performance analysis is performed using MATLAB program codes.

A solar updraft tower power plant-sometimes also called ''solar chimney'' or just ''solar tower''-is a solar thermal power plant utilizing a combination of solar air collector and central updraft tube to generate a solar induced convective flow which drives pressure staged turbines to generate electricity. The paper presents theory, practical experience, and economy of solar updraft towers: First a simplified theory of the solar tower is described. Then results from designing, building and operating a small scale prototype in Spain are presented. Eventually technical issues and basic economic data for future commercial solar tower systems like the one being planned for Australia are discussed.

With the complete utilization of the potential for value creation through the strategy of cost reduction and complete removal of underperforming assets during the era of Jack Welch, it was important for Jeff Immelt to act promptly to save the company. Additionally, with the fact that Jeff Immelt took the leadership at GE during a period when the market economy was dwindling with decreased growth and investor confidence, as well falling optimism, meant that the changes in business environment and the economic stability confronted Jeff Immelt with crucial issues to address through the identification of appropriate sources of profit (Tichy, 2007).

Knowledge management is the active transfer of knowledge throughout an organization. Such organizations may be corporations, nonprofit organizations, governments, or international agencies. It involves the capture, refinement, storage, and dissemination of knowledge. Essentially, the goal of knowledge management is to enable the successful transfer of the right knowledge to the right people, in the right format, at the right time. Methodologies for knowledge management can and should be utilized by international organizations.

Because effective operation of bioreactor landfills involves careful operation and construction of infrastructure beyond that necessary in traditional landfills, upfront capital and operating costs are greater than those associated with traditional landfills. Prior to investing in bioreactor landfills, landfill owners must be convinced that larger short-term expenses (e.g., liquid and/or air injection infrastructure) will be balanced by future economic benefits (e.g., extension of landfill life, reduced leachate treatment costs, etc.). The purpose of this paper is to describe an economic model developed to evaluate the impact of various operational (anaerobic, aerobic, or hybrid) and construction (retrofit and as-built) bioreactor landfill strategies on project economics. Model results indicate retrofit bioreactor landfills are more expensive than traditional landfills, while both the as-built and aerobic bioreactor landfills are less costly. Simulation results indicate the parameters that influence bioreactor economics most significantly are airspace recovery, gas recovery and subsequent use to generate electricity, and savings resulting from reduced leachate treatment costs.

The Gas turbine technology has steadily advanced since its inception and emerged as a strong force in the generation market. It has been an active area of research. Research and development was one of the major keys to its success. The objective of this paper is to present a survey of two gas turbine designs available from two different companies i.e., General Electric (GE) and Westinghouse used in Saudi Electricity Company for south operating area (SEC-SOA). The paper also presents a thorough study of the fuel system used in these gas turbines.

A generator powered by a stationary bicycle for the purposes of generating electricity for fitness club appliances is considered. A generator is connected to a stationary bicycle in such a way as the circular rotation of the front wheel rotates the coils of wires inside the generator between the poles of the magnets inside the generator. The resulting Direct Current is channeled to the attached battery bank and converted into different usable DC voltage levels as well as AC voltage, just to increase the number of electrical appliances possible to connect.

This study presents a PVediesel hybrid power system with battery backup for a village being fed with diesel generated electricity to displace part of the diesel by solar. The hourly solar radiation data measured at the site along with PV modules mounted on fixed foundations, four generators of different rated powers, diesel prices of 0.2e1.2US$/l, different sizes of batteries and converters were used to find an optimal power system for the village. It was found that a PV array of 2000 kW and four generators of 1250, 750, 2250 and 250 kW; operating at a load factor of 70% required to run for 3317 h/yr, 4242 h/yr, 2820 h/yr and 3150 h/yr, respectively; to produce a mix of 17,640 MWh of electricity annually and 48.33 MWh per day. The cost of energy (COE) of diesel only and PV/diesel/battery power system with 21% solar penetration was found to be 0.190$/kWh and 0.219$/kWh respectively for a diesel price of 0.2$/l. The sensitivity analysis showed that at a diesel price of 0.6$/l the COE from hybrid system become almost the same as that of the diesel only system and above it, the hybrid system become more economical than the diesel only system.

El Justo a Tiempo o JIT (Just in Time por sus siglas en inglés) es un sistema de producción basado en el manejo de inventarios o stock tendiente a cero;la optimización de las logísticas de entrega de suministros por parte de los proveedores;obtención de eficacia en tiempos y movimientos de operarios y máquinas;todo lo cual redunda en ahorro de recursos y por tanto en mayor productividad para las empresas.

Este trabajo tiene como finalidad estudiar y comparar los principales motores para aviones comerciales fabricados por las empresas Pratt & Whitney, General Electric y Rolls-Royce, además de aquellos fabricados por alianzas estratégicas en las que participan estas, como CFM International, Engine Alliance e International Aero Engines.

Anaerobic digestion applied to the organic waste produced in urban environments could provide a critical solution to growing garbage problems while simultaneously reducing external energy requirements. As landfills across Canada and the rest of the world are filled to their limits, a carbonneutral process which can locally generate electricity and heat while providing up to 50% volatile solid reduction is something to be seriously considered. This paper investigates the feasibility of urban anaerobic digestion, presents four techniques for biogas estimation e ultimate analysis, yield from molecular formula analysis, a novel computer simulation technique using Anaerobic Digestion Model #1 (ADM1), and a literature review of experimentally determined biogas yields. In addition, a case study for small-scale anaerobic digestion system design is presented for an urban building.

One of the most popular techniques of renewable energy generation is the installation of photovoltaic (PV) systems using sunlight to generate electrical power. There are many factors that affecting the operation and efficiency of the PV based electricity generation systems, such as PV cell technology, ambient conditions and selection of required equipment. There is no much study that presents all factors affecting efficiency and operation of the entire PV system, in the literature. This paper provides a detailed review of these factors and also includes suggestions for the design of more efficient systems. The presented detailed overview will be useful to people working on theory, design and/or application of photovoltaic based electricity generation systems.

The turbofan engine had many developments in the past 60 years and becomes the common power plant employed in both civil airliners and military aircrafts. It combines the advantages of both of turboprop engines (high propulsive efficiency and thrust) and turbojet engines (high flight speed and altitude). To cope with the needs of high thrust forces that propel wide body airliner and increase of their payload and range as well as enlarging maneuver capabilities of military aircrafts, successive developments of turbofan engines are needed. These developments in turbofan design have endeavors of larger thrust force, low noise and emission as well as better fuel economy. These goals were achieved by increasing of the bypass ratio (BR), fan pressure ratio (FPR), overall pressure ratio (OPR), turbine inlet temperature (TIT) as well as using new materials, production and cooling techniques for both turbines and combustion chamber such modifications led to improvements in thermal, propulsive and overall efficiencies, decreases in thrust specific fuel consumption (TSFC) and increase the specific thrust. This paper presents a parametric study and design point selection of the cold sections of high bypass ratio turbofan engine (close to GEnx-1B-70). Cold sections include the intake, the fan, and the compressor. This engine is one of the products of GE Aviation Company. Performance analysis is performed using MATLAB program code for both taking-off and cruise conditions.

The nuclear thermal rocket (NTR) provides a unique propulsion capability to planners/designers of future human exploration missions to the Moon and Mars. In addition to its high specific impulse (approximately 850-1000 s) and engine thrust-to-weight ratio (approximately 3-10), the NTR can also be configured as a 'dual mode' system capable of generating electrical power for spacecraft environmental systems, communications, and

There has been an increase in recent years in the number of reports of microorganisms that can generate electrical current in microbial fuel cells. Although many new strains have been identified, few strains individually produce power densities as high as strains from mixed ...

This paper presents an assessment of the technical and economic performance of thermal processes to generate electricity from a wood chip feedstock by combustion, gasification and fast pyrolysis. The scope of the work begins with the delivery of a wood chip feedstock at a conversion plant and ends with the supply of electricity to the grid, incorporating wood chip preparation, thermal conversion, and electricity generation in dual fuel diesel engines. Net generating capacities of 1-20 MW e are evaluated. The techno-economic assessment is achieved through the development of a suite of models that are combined to give cost and performance data for the integrated system. The models include feed pretreatment, combustion, atmospheric and pressure gasification, fast pyrolysis with pyrolysis liquid storage and transport (an optional step in de-coupled systems) and diesel engine or turbine power generation. The models calculate system efficiencies, capital costs and production costs. An identical methodology is applied in the development of all the models so that all of the results are directly comparable. The electricity production costs have been calculated for 10th plant systems, indicating the costs that are achievable in the medium term after the high initial costs associated with novel technologies have reduced. The costs converge at the larger scale with the mean electricity price paid in the EU by a large consumer, and there is therefore potential for fast pyrolysis and diesel engine systems to sell electricity directly to large consumers or for on-site generation. However, competition will be fierce at all capacities since electricity production costs vary only slightly between the four biomass to electricity systems that are evaluated. Systems de-coupling is one way that the fast pyrolysis and diesel engine system can distinguish itself from the other conversion technologies. Evaluations in this work show that situations requiring several remote generators are much better served by a large fast pyrolysis

Thermal-power electricity are important mainly because of the need for diversified power-generation and the availability of natural gas, the main fuel used in this type of electricity-generating system. With the implementation of the priority plan for thermal-power plants in Brazil, dozens of units will be installed which will make it possible to transform the Brazilian electric system, today mainly based in hydraulic principles, into a hydro-thermal system. The operation of a combined cycle thermal-power plant is influenced by the conditions that are present at the place where it is installed, mainly ambient temperature, atmospheric pressure and the air's relative-humidity. These parameters affect the generated electric-power and the heat-rate during operation. Among these variables, the ambient temperature causes the greatest performance variation during operation. That is the reason why the influence of this variable on this type of generating unit is studied. The plant selected for this study has a multiple-shaft configuration and is composed of two Siemens AG 501F gas-turbines, coupled to three pressure levels HRSGs and re-heating with supplementary firing and a steam-turbine. The most relevant results obtained from a thermodynamic simulation, in which the Gate Cycle Software version 5.51.0.r was used, are the curves of generated power, as well as the heat rate and thermal efficiency as functions of ambient temperature and the supplementary firing.

Sugarcane bagasse is becoming more and more commonly used in generating electrical energy, steam, and bioethanol. Drying is important in sugarcane and other types of biomass because it can be used to improve the calorific value and overall energetic use. In this work, sugarcane bagasse was treated by drying in a cyclonic dryer. The influence of the geometry of the device (the conical part of the cyclone) and process parameters (bagasse mass flow rate and temperature) were tested. The modification on the conical part was related to two different angles and with two different inferior outlets (B). Experimental design was carried out for each geometry. The independent variables were the drying agent temperature (35 to 275°C) and the bagasse mass flow rate (0.1 × 10−2 to 2.9 × 10−2 kg s−1). The air flow rate was kept constant at 7.5 × 10−2 kg s−1. The dependent variables were moisture reduction (MR) and average particle residence time (tres) in the cyclonic dryer. For both cyclonic geometries, it was observed that MR was directly proportional to the temperature and inversely proportional to the bagasse mass flow rate. tres was also inversely proportional to the bagasse mass flow rate. Decreasing B tended to increase tres and MR.

Microbial fuel cells (MFCs) can be used to directly generate electricity from the oxidation of dissolved organic matter, but optimization of MFCs will require that we know more about the factors that can increase power output such as the type of proton exchange system which can affect the system internal resistance. Power output in a MFC containing a proton exchange membrane was compared using a pure culture (Geobacter metallireducens) or a mixed culture (wastewater inoculum). Power output with either inoculum was essentially the same, with 4071 mW/m 2 for G. metallireducens and 3871 mW/m 2 for the wastewater inoculum. We also examined power output in a MFC with a salt bridge instead of a membrane system. Power output by the salt bridge MFC (inoculated with G. metallireducens) was 2.2 mW/m 2 . The low power output was directly attributed to the higher internal resistance of the salt bridge system ð19920 AE 50 OÞ compared to that of the membrane system ð1286 AE 1 OÞ based on measurements using impedance spectroscopy. In both systems, it was observed that oxygen diffusion from the cathode chamber into the anode chamber was a factor in power generation. Nitrogen gas sparging, L-cysteine (a chemical oxygen scavenger), or suspended cells (biological oxygen scavenger) were used to limit the effects of gas diffusion into the anode chamber. Nitrogen gas sparging, for example, increased overall Coulombic efficiency (47% or 55%) compared to that obtained without gas sparging (19%). These results show that increasing power densities in MFCs will require reducing the internal resistance of the system, and that methods are needed to control the dissolved oxygen flux into the anode chamber in order to increase overall Coulombic efficiency. r