853 resultados para energy demand


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Like many other Caribbean countries, Grenada, Saint Lucia and Saint Vincent and the Grenadines are almost entirely dependent on imported petroleum as their primary source of energy. In this regard, many countries in the subregion have taken a strategic approach to long-term planning in the energy sector towards creating higher levels of efficiency on both the demand and supply sides as well as promoting diversification in the energy mix. Within this context, this study was conducted to present mechanisms to improve energy efficiency (EE) in the transport sector in Grenada, Saint Lucia and Saint Vincent and the Grenadines. For each country, the report presents a brief description of current trends in energy consumption generally as well as energy issues in the transport sector and programmes, initiatives and regulatory mechanisms currently in place that are contributing to energy efficiency in the sector.

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The energy sector is a dominant one in Trinidad and Tobago and it plays an important role in the twin-island republic‟s economy. In 2008, the share of the energy sector in gross domestic product (GDP) amounted to approximately 48% while contributing 57% to total Government revenue. In that same year, the sector‟s share of merchandise exports was 88%, made up mainly of refined oil products including petroleum, liquefied natural gas (LNG), and natural gas liquids (Central Bank of Trinidad and Tobago, 2009). Trinidad and Tobago is the main exporter of oil in the Caribbean region and the main producer of liquefied natural gas in Latin America and the Caribbean. The role of the country‟s energy sector is, therefore, not limited to serving as the engine of growth for the national economy but also includes providing energy security for the small island developing States of the Caribbean. However, with its hydrocarbon-based economy, Trinidad and Tobago is ranked seventh in the world in terms of carbon dioxide (CO2) emissions per capita, producing an estimated 40 million tonnes of CO2 annually. Almost 90% of these CO2 emissions are attributed directly to the energy sector through petrochemical production (56%), power generation (30%) and flaring (3%). Trinidad and Tobago is a ratified signatory to the United Nations Framework Convention on Climate Change and the Kyoto Protocol. Although, as a non-Annex 1 country, Trinidad and Tobago is not required to cut its greenhouse gas emissions under the Protocol, it is currently finalizing a climate change policy document as well as a national energy policy with specific strategies to address climate change. The present study complements the climate change policy document by providing an economic analysis of the impact that climate change could have on the energy sector in Trinidad and Tobago under the Intergovernmental Panel on Climate Change alternative climate scenarios (A2 and B2) as compared to a baseline situation of no climate change. Results of analyses indicate that, in the short-run, climate change, represented by change in temperature, is not a significant determinant of domestic consumption of energy, electricity in particular, in Trinidad and Tobago. With energy prices subsidized domestically and fixed for years at a time, energy price does not play a role in determining electricity demand. Economic growth, as indicated by Gross Domestic Product (GDP), is the single major determinant of electricity consumption in the short-run. In the long-run, temperature, GDP, and patterns of electricity use, jointly determine electricity consumption. Variations in average annual temperature due to climate change for the A2 scenario are expected to lead to an increase in electricity consumption per capita, equivalent to an annual increase of 1.07% over the 2011 baseline value of electricity consumption per capita. Under the B2 scenario, the average annual increase in electricity consumption per capita over the 2011 baseline value is expected to be 1.01%. The estimated economic impact of climate change on electricity consumption for the period 2011-2050 is valued at US$ 142.88 million under the A2 scenario and US$ 134.83million under the B2 scenario. These economic impact estimates are equivalent to a loss of 0.737% of 2009 GDP under the A2 climate scenario and a loss of 0.695% of 2009 GDP under the B2 scenario. On the energy supply side, sea level rise and storm surges present significant risks to oil installations and infrastructure at the Petroleum Company of Trinidad and Tobago (PETROTRIN) Pointe-a-Pierre facilities (Singh and El Fouladi, 2006). However, data limitations do not permit the conduct of an economic analysis of the impact of projected sea level rise on oil and gas production.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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The effects of the clinical and dietetics in patient managements on the protein-energy status of hospitalized patients were retrospectively (four yr) investigated in 243 adult (49 +/- 16 yr), male (168) and female (75) patients suffering from chronic liver diseases (42%), intestinal diseases with diarrhea (14%), digestive cancers (11%), chronic pancreatitis (10%), stomach and duodenum diseases (7%), acute pancreatitis (7%), primary protein-energy malnutrition (3%), esophagus diseases (3%), intestinal diseases with constipation 14 (2%) and chronic alcoholism (2%). The protein-energy nutritional status assessed by combinations of anthropometric and blood parameters showed 75% of protein energy malnutrition at the hospital entry mostly (4/5) in severe and moderate grades. The overall average of hospitalization was 20 +/- 15 days being the shortest (13 +/- 5,7 days) for esophagus diseases and the longest (28 +/- 21 days) for the intestinal diseases with diarrhea patients which also received mostly (42%) of the enteral and/or parenteral feedings followed by acute pacreatitis (41%) and digestive cancers (31%) patients. When compared to the entry the protein-energy malnutrition rate at the discharge decreased only 5% despite the increasing of 30% found on the protein-energy intake. The main improvement of the protein-energy nutritional status were attained to those patients showing protein-energy malnutrition milder degrees at the entry which belonged mostly to primary protein-energy malnutrition, acute pancreatitis and intestinal diseases with diarrhea diseases. The later two groups showed protein-energy nutritional status improvement only after the second week of hospitalization. The digestive cancers patients had their protein-energy nutritional status worsened throughout the hospitalization whereas it happened only in the first week for the intestinal diseases with diarrhea and chronic liver diseases patients, improving thereafter up to the discharge. The protein-energy nutritional status improvement found in few patients could be attributed to some complementary factors such as theirs mild degree of protein-energy malnutrition at entry and/or non-invasive propedeutics and/or enteral-parenteral feddings and/or longer hospitalization staying. The institutional causes for the unexpected lack of nutritional responses by the patients were probably the high demand for the few available beds which favour the hospitalization of the most severed patients and the university-teaching pressure for the high rotation of the available beds. Both often resulting in early discharging. In persisting the current physical area and attendance demand one could suggest an aggressive support early at the entry preceding and/or accompanying the more invasive propedeutical procedures.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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This study evaluates the potential for using different effluents for simultaneous H-2 and CH4 production in a two-stage batch fermentation process with mixed microflora. An appreciable amount of H-2 was produced from parboiled rice wastewater (23.9 mL g(-1) chemical oxygen demand [COD]) and vinasse (20.8 mL g(-1) COD), while other effluents supported CH4 generation. The amount of CH4 produced was minimum for sewage (46.3 mL g(-1) COD), followed by parboiled rice wastewater (115.5 mL g(-1) COD) and glycerol (180.1 mL g(-1) COD). The maximum amount of CH4 was observed for vinasse (255.4 mL g(-1) COD). The total energy recovery from vinasse (10.4 kJ g(-1) COD) corresponded to the maximum COD reduction (74.7 %), followed by glycerol (70.38 %, 7.20 kJ g(-1) COD), parboiled rice wastewater (63.91 %, 4.92 kJ g(-1) COD), and sewage (51.11 %, 1.85 kJ g(-1) COD). The relatively high performance of vinasse in such comparisons could be attributed to the elevated concentrations of macronutrients contained in raw vinasse. The observations are based on kinetic parameters of H-2 and CH4 production and global energy recovery of the process. These observations collectively suggest that organic-rich effluents can be deployed for energy recovery with sequential generation of H-2 and CH4.

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Water is the driving force in nature. We use water for washing cars, doing laundry, cooking, taking a shower, but also to generate energy and electricity. Therefore water is a necessary product in our daily lives (USGS. Howard Perlman, 2013). The model that we created is based on the urban water demand computer model from the Pacific Institute (California). With this model we will forecast the future urban water use of Emilia Romagna up to the year of 2030. We will analyze the urban water demand in Emilia Romagna that includes the 9 provinces: Bologna, Ferrara, Forli-Cesena, Modena, Parma, Piacenza, Ravenna, Reggio Emilia and Rimini. The term urban water refers to the water used in cities and suburbs and in homes in the rural areas. This will include the residential, commercial, institutional and the industrial use. In this research, we will cover the water saving technologies that can help to save water for daily use. We will project what influence these technologies have to the urban water demand, and what it can mean for future urban water demands. The ongoing climate change can reduce the snowpack, and extreme floods or droughts in Italy. The changing climate and development patterns are expected to have a significant impact on water demand in the future. We will do this by conducting different scenario analyses, by combining different population projections, climate influence and water saving technologies. In addition, we will also conduct a sensitivity analyses. The several analyses will show us how future urban water demand is likely respond to changes in water conservation technologies, population, climate, water price and consumption. I hope the research can contribute to the insight of the reader’s thoughts and opinion.

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Beside the traditional paradigm of "centralized" power generation, a new concept of "distributed" generation is emerging, in which the same user becomes pro-sumer. During this transition, the Energy Storage Systems (ESS) can provide multiple services and features, which are necessary for a higher quality of the electrical system and for the optimization of non-programmable Renewable Energy Source (RES) power plants. A ESS prototype was designed, developed and integrated into a renewable energy production system in order to create a smart microgrid and consequently manage in an efficient and intelligent way the energy flow as a function of the power demand. The produced energy can be introduced into the grid, supplied to the load directly or stored in batteries. The microgrid is composed by a 7 kW wind turbine (WT) and a 17 kW photovoltaic (PV) plant are part of. The load is given by electrical utilities of a cheese factory. The ESS is composed by the following two subsystems, a Battery Energy Storage System (BESS) and a Power Control System (PCS). With the aim of sizing the ESS, a Remote Grid Analyzer (RGA) was designed, realized and connected to the wind turbine, photovoltaic plant and the switchboard. Afterwards, different electrochemical storage technologies were studied, and taking into account the load requirements present in the cheese factory, the most suitable solution was identified in the high temperatures salt Na-NiCl2 battery technology. The data acquisition from all electrical utilities provided a detailed load analysis, indicating the optimal storage size equal to a 30 kW battery system. Moreover a container was designed and realized to locate the BESS and PCS, meeting all the requirements and safety conditions. Furthermore, a smart control system was implemented in order to handle the different applications of the ESS, such as peak shaving or load levelling.

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Pneumococcal meningitis causes neurological sequelae, including learning and memory deficits in up to half of the survivors. In both humans and in animal models of the disease, there is apoptotic cell death in the hippocampus, a brain region involved in learning and memory function. We previously demonstrated that in an infant rat model of pneumococcal meningitis, there is activation of the kynurenine (KYN) pathway in the hippocampus, and that there was a positive correlation between the concentration of 3-hydroxykynurenine and the extent of hippocampal apoptosis. To clarify the role of the KYN pathway in the pathogenesis of hippocampal apoptosis in pneumococcal meningitis, we specifically inhibited 2 key enzymes of the KYN pathway and assessed hippocampal apoptosis, KYN pathway metabolites, and nicotinamide adenine dinucleotide (NAD) concentrations by high-performance liquid chromatography. Pharmacological inhibition of kynurenine 3-hydroxylase and kynureninase led to decreased cellular NAD levels and increased apoptosis in the hippocampus. The cerebrospinal fluid levels of tumor necrosis factor and interleukin-1? and -? were not affected. Our data suggest that activation of the KYN pathway in pneumococcal meningitis is neuroprotective by compensating for an increased NAD demand caused by infection and inflammation;this mechanism may prevent energy failure and apoptosis in the hippocampus.

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Solar energy is the most abundant persistent energy resource. It is also an intermittent one available for only a fraction of each day while the demand for electric power never ceases. To produce a significant amount of power at the utility scale, electricity generated from solar energy must be dispatchable and able to be supplied in response to variations in demand. This requires energy storage that serves to decouple the intermittent solar resource from the load and enables around-the-clock power production from solar energy. Practically, solar energy storage technologies must be efficient as any energy loss results in an increase in the amount of required collection hardware, the largest cost in a solar electric power system. Storing solar energy as heat has been shown to be an efficient, scalable, and relatively low-cost approach to providing dispatchable solar electricity. Concentrating solar power systems that include thermal energy storage (TES) use mirrors to focus sunlight onto a heat exchanger where it is converted to thermal energy that is carried away by a heat transfer fluid and used to drive a conventional thermal power cycle (e.g., steam power plant), or stored for later use. Several approaches to TES have been developed and can generally be categorized as either thermophysical (wherein energy is stored in a hot fluid or solid medium or by causing a phase change that can later be reversed to release heat) or thermochemical (in which energy is stored in chemical bonds requiring two or more reversible chemical reactions).

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In the U.S., many electric utility companies are offering demand-side management (DSM) programs to their customers as ways to save money and energy. However, it is challenging to compare these programs between utility companies throughout the U.S. because of the variability of state energy policies. For example, some states in the U.S. have deregulated electricity markets and others do not. In addition, utility companies within a state differ depending on ownership and size. This study examines 12 utilities’ experiences with DSM programs and compares the programs’ annual energy savings results that the selected utilities reported to the Energy Information Administration (EIA). The 2009 EIA data suggests that DSM program effectiveness is not significantly affected by electricity market deregulation or utility ownership. However, DSM programs seem to generally be more effective when administered by utilities located in states with energy savings requirements and DSM program mandates.

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Various applications for the purposes of event detection, localization, and monitoring can benefit from the use of wireless sensor networks (WSNs). Wireless sensor networks are generally easy to deploy, with flexible topology and can support diversity of tasks thanks to the large variety of sensors that can be attached to the wireless sensor nodes. To guarantee the efficient operation of such a heterogeneous wireless sensor networks during its lifetime an appropriate management is necessary. Typically, there are three management tasks, namely monitoring, (re) configuration, and code updating. On the one hand, status information, such as battery state and node connectivity, of both the wireless sensor network and the sensor nodes has to be monitored. And on the other hand, sensor nodes have to be (re)configured, e.g., setting the sensing interval. Most importantly, new applications have to be deployed as well as bug fixes have to be applied during the network lifetime. All management tasks have to be performed in a reliable, time- and energy-efficient manner. The ability to disseminate data from one sender to multiple receivers in a reliable, time- and energy-efficient manner is critical for the execution of the management tasks, especially for code updating. Using multicast communication in wireless sensor networks is an efficient way to handle such traffic pattern. Due to the nature of code updates a multicast protocol has to support bulky traffic and endto-end reliability. Further, the limited resources of wireless sensor nodes demand an energy-efficient operation of the multicast protocol. Current data dissemination schemes do not fulfil all of the above requirements. In order to close the gap, we designed the Sensor Node Overlay Multicast (SNOMC) protocol such that to support a reliable, time-efficient and energy-efficient dissemination of data from one sender node to multiple receivers. In contrast to other multicast transport protocols, which do not support reliability mechanisms, SNOMC supports end-to-end reliability using a NACK-based reliability mechanism. The mechanism is simple and easy to implement and can significantly reduce the number of transmissions. It is complemented by a data acknowledgement after successful reception of all data fragments by the receiver nodes. In SNOMC three different caching strategies are integrated for an efficient handling of necessary retransmissions, namely, caching on each intermediate node, caching on branching nodes, or caching only on the sender node. Moreover, an option was included to pro-actively request missing fragments. SNOMC was evaluated both in the OMNeT++ simulator and in our in-house real-world testbed and compared to a number of common data dissemination protocols, such as Flooding, MPR, TinyCubus, PSFQ, and both UDP and TCP. The results showed that SNOMC outperforms the selected protocols in terms of transmission time, number of transmitted packets, and energy-consumption. Moreover, we showed that SNOMC performs well with different underlying MAC protocols, which support different levels of reliability and energy-efficiency. Thus, SNOMC can offer a robust, high-performing solution for the efficient distribution of code updates and management information in a wireless sensor network. To address the three management tasks, in this thesis we developed the Management Architecture for Wireless Sensor Networks (MARWIS). MARWIS is specifically designed for the management of heterogeneous wireless sensor networks. A distinguished feature of its design is the use of wireless mesh nodes as backbone, which enables diverse communication platforms and offloading functionality from the sensor nodes to the mesh nodes. This hierarchical architecture allows for efficient operation of the management tasks, due to the organisation of the sensor nodes into small sub-networks each managed by a mesh node. Furthermore, we developed a intuitive -based graphical user interface, which allows non-expert users to easily perform management tasks in the network. In contrast to other management frameworks, such as Mate, MANNA, TinyCubus, or code dissemination protocols, such as Impala, Trickle, and Deluge, MARWIS offers an integrated solution monitoring, configuration and code updating of sensor nodes. Integration of SNOMC into MARWIS further increases performance efficiency of the management tasks. To our knowledge, our approach is the first one, which offers a combination of a management architecture with an efficient overlay multicast transport protocol. This combination of SNOMC and MARWIS supports reliably, time- and energy-efficient operation of a heterogeneous wireless sensor network.