Ciclo de cogeração a partir de resíduos de poda de árvores na cidade de Guaratinguetá

The current socio-economic situation has brought a need to look for alternative ways to get energy that allow reducing the high dependence on fossil fuel sources while deflect from the climate change arising from the result of the use of these energy resources. Renewable sources of energy, low and medium temperature appear as high potential of energy resources, which have a major influence on the way of life of the people to enable decentralized energy production. In Brazil, in particular, have also the need to decentralize the energy grid, currently focused on energy from water source. The current water crisis, exemplifies the urgency of betting on other energy sources, as a way to help in emergency situations such as the current one. Therefore, this study evaluates the possibility of using biomass as a heat source in a Rankine Cycle Organic where instead of water; it uses thermal fluid as working fluid, was compared the urban areas of the city of Guaratinguetá with the urban area of the metropolitan region of São Paulo. Thus, it was established two scenarios, so it was possible to establish the cycle to be used

Group Rekeying Schemes for Secure Group Communication in Wireless Sensor Networks

Wireless sensor networks are promising solutions for many applications. However, wireless sensor nodes suffer from many constraints such as low computation capability, small memory, limited energy resources, and so on. Grouping is an important technique to localize computation and reduce communication overhead in wireless sensor networks. In this paper, we use grouping to refer to the process of combining a set of sensor nodes with similar properties. We propose two centralized group rekeying (CGK) schemes for secure group communication in sensor networks. The lifetime of a group is divided into three phases, i.e., group formation, group maintenance, and group dissolution. We demonstrate how to set up the group and establish the group key in each phase. Our analysis shows that the proposed two schemes are computationally efficient and secure.

Ciclo de cogeração a partir de resíduos de poda de árvores na cidade de Guaratinguetá

The current socio-economic situation has brought a need to look for alternative ways to get energy that allow reducing the high dependence on fossil fuel sources while deflect from the climate change arising from the result of the use of these energy resources. Renewable sources of energy, low and medium temperature appear as high potential of energy resources, which have a major influence on the way of life of the people to enable decentralized energy production. In Brazil, in particular, have also the need to decentralize the energy grid, currently focused on energy from water source. The current water crisis, exemplifies the urgency of betting on other energy sources, as a way to help in emergency situations such as the current one. Therefore, this study evaluates the possibility of using biomass as a heat source in a Rankine Cycle Organic where instead of water; it uses thermal fluid as working fluid, was compared the urban areas of the city of Guaratinguetá with the urban area of the metropolitan region of São Paulo. Thus, it was established two scenarios, so it was possible to establish the cycle to be used

El gran reto de la integración de la electricidad de origen renovable en las redes eléctricas de Canarias

[ES] Las Islas Canarias carecen totalmente de recursos energéticos convencionales, representando la importación de energía primaria un 98% del consumo del Archipiélago. En la actualidad las Islas se suministran de petróleo y sus derivados, importándolos mediante buques. Sin embargo, Canarias posee un alto potencial de energías renovables, energías autóctonas y limpias, pero tan sólo un 2% del consumo de energía primaria procede de energías renovables. La búsqueda de la sostenibilidad energética es uno de los grandes desafíos de Canarias y la integración de la electricidad de origen renovable en sus redes eléctricas uno de los grandes retos que podría convertir a Canarias en un laboratorio a nivel mundial; el ejemplo de la isla de El Hierro así lo constata. Este artículo versa sobre este gran reto que supone la integración de energías renovables en las redes eléctricas de Canarias.

Cooperative communication and distributed detection in wireless sensor networks

Recent progress in microelectronic and wireless communications have enabled the development of low cost, low power, multifunctional sensors, which has allowed the birth of new type of networks named wireless sensor networks (WSNs). The main features of such networks are: the nodes can be positioned randomly over a given field with a high density; each node operates both like sensor (for collection of environmental data) as well as transceiver (for transmission of information to the data retrieval); the nodes have limited energy resources. The use of wireless communications and the small size of nodes, make this type of networks suitable for a large number of applications. For example, sensor nodes can be used to monitor a high risk region, as near a volcano; in a hospital they could be used to monitor physical conditions of patients. For each of these possible application scenarios, it is necessary to guarantee a trade-off between energy consumptions and communication reliability. The thesis investigates the use of WSNs in two possible scenarios and for each of them suggests a solution that permits to solve relating problems considering the trade-off introduced. The first scenario considers a network with a high number of nodes deployed in a given geographical area without detailed planning that have to transmit data toward a coordinator node, named sink, that we assume to be located onboard an unmanned aerial vehicle (UAV). This is a practical example of reachback communication, characterized by the high density of nodes that have to transmit data reliably and efficiently towards a far receiver. It is considered that each node transmits a common shared message directly to the receiver onboard the UAV whenever it receives a broadcast message (triggered for example by the vehicle). We assume that the communication channels between the local nodes and the receiver are subject to fading and noise. The receiver onboard the UAV must be able to fuse the weak and noisy signals in a coherent way to receive the data reliably. It is proposed a cooperative diversity concept as an effective solution to the reachback problem. In particular, it is considered a spread spectrum (SS) transmission scheme in conjunction with a fusion center that can exploit cooperative diversity, without requiring stringent synchronization between nodes. The idea consists of simultaneous transmission of the common message among the nodes and a Rake reception at the fusion center. The proposed solution is mainly motivated by two goals: the necessity to have simple nodes (to this aim we move the computational complexity to the receiver onboard the UAV), and the importance to guarantee high levels of energy efficiency of the network, thus increasing the network lifetime. The proposed scheme is analyzed in order to better understand the effectiveness of the approach presented. The performance metrics considered are both the theoretical limit on the maximum amount of data that can be collected by the receiver, as well as the error probability with a given modulation scheme. Since we deal with a WSN, both of these performance are evaluated taking into consideration the energy efficiency of the network. The second scenario considers the use of a chain network for the detection of fires by using nodes that have a double function of sensors and routers. The first one is relative to the monitoring of a temperature parameter that allows to take a local binary decision of target (fire) absent/present. The second one considers that each node receives a decision made by the previous node of the chain, compares this with that deriving by the observation of the phenomenon, and transmits the final result to the next node. The chain ends at the sink node that transmits the received decision to the user. In this network the goals are to limit throughput in each sensor-to-sensor link and minimize probability of error at the last stage of the chain. This is a typical scenario of distributed detection. To obtain good performance it is necessary to define some fusion rules for each node to summarize local observations and decisions of the previous nodes, to get a final decision that it is transmitted to the next node. WSNs have been studied also under a practical point of view, describing both the main characteristics of IEEE802:15:4 standard and two commercial WSN platforms. By using a commercial WSN platform it is realized an agricultural application that has been tested in a six months on-field experimentation.

Biomasse e loro quantificazione economica per un efficiente uso dell'energia

Biomasses and their possible use as energy resource are of great interest today, and the general problem of energy resources as well. In the present study the key questions of the convenience, from both energy and economy standpoints, have been addressed without any bias: the problem has been handled starting from “philosophical” bases disregarding any pre-settled ideology or political trend, but simply using mathematical approaches as logical tools for defining balances in a right way. In this context quantitative indexes such as LCA and EROEI have been widely used, together with multicriteria methods (such as ELECTRE) as decision supporting tools. This approach permits to remove mythologies, such as the unrealistic concept of clean energy, or the strange idea of biomasses as a magic to solve every thing in the field of the energy. As a consequence the present study aims to find any relevant aspect potentially useful for the society, looking at any possible source of energy without prejudices but without unrealistic expectations too. For what concerns biomasses, we studied in great details four very different cases of study, in order to have a scenario as various as much we can. A relevant result is the need to use biomasses together with other more efficient sources, especially recovering by-products from silviculture activities: but attention should be paid to the transportation and environmental costs. Another relevant result is the very difficult possibility of reliable evaluation of dedicated cultures as sources for “biomasses for energy”: the problem has to be carefully evaluated case-by-case, because what seems useful in a context, becomes totally disruptive in another one. In any case the concept itself of convenience is not well defined at a level of macrosystem: it seems more appropriate to limit this very concept at a level of microsystem, considering that what sounds fine in a limited well defined microsystem may cause great damage in another slightly different, or even very similar, microsystem. This approach seems the right way to solve the controversy about the concept of convenience.

Luminophores and Carbon nanostructures: towards new functional materials

In the scenario of depleting fossil fuels, finding new energy technologies and conserving conventional energy resources have become essential to sustain modern civilization. While renewable energies are on the rise, considerable interest has been turned also to reduce energy consumption of conventional devices and appliances, which are often not yet optimized for this purpose. Modern nanotechnology provides a platform to build such devices by using nanomaterials showing exceptional physico-chemical properties. In particular, carbon materials (fullerenes, carbon nanotubes, graphene etc.), which show high thermal and electrical conductivity, aspect ratio, shear strength and chemical/mechanical resistance, are quite promising for a wide range of applications. However, the problem of solubility often hampers their handling and industrial utilization. These limitations can be mitigated by functionalizing carbon nanostructures, either covalently or non covalently, with organic or inorganic compounds. The exo- and endohedral functionalization of carbon nanotubes (CNTs) with organic/inorganic moieties to produce luminescent materials with desired properties are the main focus of this doctoral work. These hybrids have been thoroughly designed and characterized with chemical, microscopic and photophysical analyses. All the materials based on carbon nanostructures described in this thesis are innovative examples of photoactive and luminescent hybrids, and their morphological and photophysical properties help understanding the nature of interactions between the active units. This may prompt the design and fabrication of new functional materials for applications in the fields of optoelectronics and photovoltaics.

Prestazioni energetico-ambientali di sistemi cogenerativi avanzati e analisi di casi applicativi

Lo scopo di questa tesi è quello di analizzare dapprima l’impatto ambientale di tali impianti e poi analizzare il contributo effettivo che oggi la tecnologia innovativa dei cicli Rankine organici può dare nella valorizzazione elettrica del calore di scarto di processi industriali, focalizzando l’obiettivo principalmente sulle turbine a gas ed eseguendo un caso di studio in un settore ancora poco esplorato da questa tecnologia, quello Oil&Gas. Dopo aver effettuato il censimento degli impianti a fonti fossili e rinnovabili, cogenerativi e non, presenti in Emilia-Romagna, è stato sviluppato un software chiamato MiniBref che permette di simulare il funzionamento di una qualsiasi centrale termoelettrica grazie alla possibilità di combinare la tecnologia dell’impianto con il tipo di combustibile consentendo la valutazione delle emissioni inquinanti ed i potenziali di inquinamento. Successivamente verranno illustrati gli ORC, partendo dalle caratteristiche impiantistiche e termodinamiche fino ad arrivare alla scelta del fluido organico, fondamentale per le performance del ciclo. Dopo aver effettuato una ricognizione dello stato dell’arte delle applicazioni industriali degli ORC nel recupero termico, verranno eseguite simulazioni numeriche per ricostruire gli ORC ed avere una panoramica il più completa ed attendibile delle prestazioni effettive di questi sistemi. In ultimo verranno illustrati i risultati di un caso di studio che vede l’adozione di recupero mediante ciclo organico in un’installazione esistente del settore Oil&Gas. Si effettuerà uno studio delle prestazione dell’impianto al variare delle pressioni massime e minime del ciclo ed al variare del fluido impiegato al fine di mostrare come questi parametri influenzino non solo le performance ma anche le caratteristiche impiantistiche da adottare. A conclusione del lavoro si riporteranno i risultati relativi all’analisi condotte considerando l’impianto ai carichi parziali ed in assetto cogenerativo.

Modelling and analysis of networked control strategies in smart power distribution grids: development of co-simulation tools

This thesis is focused on Smart Grid applications in medium voltage distribution networks. For the development of new applications it appears useful the availability of simulation tools able to model dynamic behavior of both the power system and the communication network. Such a co-simulation environment would allow the assessment of the feasibility of using a given network technology to support communication-based Smart Grid control schemes on an existing segment of the electrical grid and to determine the range of control schemes that different communications technologies can support. For this reason, is presented a co-simulation platform that has been built by linking the Electromagnetic Transients Program Simulator (EMTP v3.0) with a Telecommunication Network Simulator (OPNET-Riverbed v18.0). The simulator is used to design and analyze a coordinate use of Distributed Energy Resources (DERs) for the voltage/var control (VVC) in distribution network. This thesis is focused control structure based on the use of phase measurement units (PMUs). In order to limit the required reinforcements of the communication infrastructures currently adopted by Distribution Network Operators (DNOs), the study is focused on leader-less MAS schemes that do not assign special coordinating rules to specific agents. Leader-less MAS are expected to produce more uniform communication traffic than centralized approaches that include a moderator agent. Moreover, leader-less MAS are expected to be less affected by limitations and constraint of some communication links. The developed co-simulator has allowed the definition of specific countermeasures against the limitations of the communication network, with particular reference to the latency and loss and information, for both the case of wired and wireless communication networks. Moreover, the co-simulation platform has bee also coupled with a mobility simulator in order to study specific countermeasures against the negative effects on the medium voltage/current distribution network caused by the concurrent connection of electric vehicles.

Proceedings of the Eleventh Annual Biochemical Engineering Symposium

This is the eleventh in a series of symposia devoted to talks by students on their biochemical engineering research. The first, third, fifth, and ninth were at Kansas State University in Manhattan; the second and fourth were at the University of Nebraska–Lincoln; the sixth was in Kansas City in conjunction with the 8lst American Institute of Chemical Engineers National Meeting; the seventh and the tenth were at Iowa State University in Ames; and the eighth was held at the University of Missouri–Columbia. ContentsPretreatment of Wheat Straw for Cellulose Hydrolysis, M. M. Gharpuray, Yong-Hyun Lee, and L. T. Fan, Kansas State University Sugar Production During Autohydrolysis of Wheat Straw, Robert A. Lewis, Colorado State University An Alkaline Copper Reagent for Use in Automated Analysis, Alfred R. Fratzke, Iowa State University Sugars Produced During Extrusion Processing of Corn, Ruth S. Korn, Colorado State University Characterization and Comparison of Renewable Energy Resources, Snehal A. Patel, Kansas State University Anaerobic Digestion of Alcohol Stillage, Laureen K. Binder, Colorado State University Estimation of Growth Yield and Maintenance Parameters, Bamidele 0. Solomon and Mehmet D. Oner, Kansas State University Immobilization of Glucoamylase Using TiCl4 and Organic Titanates, Robert E. Lesch, Iowa State University Solvent Toxicity in the Acetone-Butanol Fermentation, Jeanine M. Costa, Colorado State University

Export Restrictions in relation to Extractive Industries

A new E15 Think Piece by Ilaria Espa produced under the E15Initiative (E15). Implemented jointly by the International Centre for Trade and Sustainable Development (ICTSD) and the World Economic Forum, the E15 convenes world-class experts and institutions to generate strategic analysis and recommendations for government, business and civil society geared towards strengthening the global trade system. This paper considers concrete policy options to better regulate the use of export restrictions in relation to extractive industries. It briefly describes recent trends in the use of export restrictions on mineral and energy resources. It gives an account of the main shortcomings in the WTO legal treatment of export restrictions. It accordingly discusses possible avenues for reforming existing WTO disciplines in the interest of secure access to supplies, while still taking into account the need to preserve some policy space for host countries to use such measures as legitimate development tools.

Elevated pCO2 causes developmental delay in early larval Pacific oysters, Crassostrea gigas

Increasing atmospheric CO2 equilibrates with surface seawater, elevating the concentration of aqueous hydrogen ions. This process, ocean acidification, is a future and contemporary concern for aquatic organisms, causing failures in Pacific oyster (Crassostrea gigas) aquaculture. This experiment determines the effect of elevated pCO2 on the early development of C. gigas larvae from a wild Pacific Northwest population. Adults were collected from Friday Harbor, Washington, USA (48°31.7' N, 12°1.1' W) and spawned in July 2011. Larvae were exposed to Ambient (400 µatm CO2), MidCO2 (700 µatm), or HighCO2 (1,000 µatm). After 24 h, a greater proportion of larvae in the HighCO2 treatment were calcified as compared to Ambient. This unexpected observation is attributed to increased metabolic rate coupled with sufficient energy resources. Oyster larvae raised at HighCO2 showed evidence of a developmental delay by 3 days post-fertilization, which resulted in smaller larvae that were less calcified.

Why do oil importers diversify their import sources politically? : evidence from U.S. firm-level data

International politics affects oil trade. But why? We construct a firm-level dataset for all U.S. oil-importing companies over 1986-2008 to examine what kinds of firms are more responsive to change in "political distance" between the U.S. and her trading partners, measured by divergence in their UN General Assembly voting patterns. Consistent with previous macro evidence, we first show that individual firms diversify their oil imports politically, even after controlling for unobserved firm heterogeneity. We conjecture that the political pattern of oil imports from these individual firms is driven by hold-up risks, because oil trade is often associated with backward vertical FDI. To test this hold-up risk hypothesis, we investigate heterogeneity in responses by matching transaction-level import data with firm-level worldwide reserves. Our results show that long-run oil import decisions are indeed more elastic for firms with oil reserves overseas than those without, although the reverse is true in the short run. We interpret this empirical regularity as that while firms trade in the spot market can adjust their imports immediately, vertically-integrated firms with investment overseas tend to commit to term contracts in the short run even though they are more responsive to changes in international politics in the long run.

The effects of international politics on oil-exporting developing countries

International politics affects oil trade. But does it affect the oil-exporting developing countries more? We construct a firm-level dataset for all U.S. oil-importing companies over 1986-2008 to examine how these firms respond to changes in "political distance" between the U.S. and her trading partners, measured by divergence in their UN General Assembly voting patterns. Consistent with previous macro evidence, we first show that individual firms diversify their oil imports politically, even after controlling for unobserved firm heterogeneity. We conjecture that the political pattern of oil imports from these individual firms is driven by hold-up risks, because oil trade is often associated with backward vertical FDI. To the extent that developing countries have higher hold-up risks because of their weaker institutions, the political effect on oil trade should be more significant in the developing world. We find that oil import decisions are indeed more elastic when firms import from developing countries, although the reverse is true in the short run. Our results suggest that international politics can affect oil revenue and hence long-term development in the developing world.

ロシアの中東政策 -- プーチン大統領のシリア政策を通じて

The active initiative taken by Russian President Vladamir Putin by bombarding the antigovernment forces in Syria at the end of September 2015 startled the world by its precalculated boldness. Russian intervention has radically changed the dynamic of the war by empowering the Syrian government of Bashar Assad, and has resulted in a ceasefire agreement which starts on 27th February 2016, led by Russia and the US. No one can predict at present the next stage of conflicts in Syria or whether it will result in a positive solution to the tragic wars there. However, there is no denying the fact that Russia has played an important role in the development of the game. This paper analyzes the motivations of Putin in intervening in the Syrian crisis and the factors which have enabled Russia to play an enlarged role in the Middle East, seemingly beyond its objective capabilities. Legacies of international networks built during the Soviet period; shrewd tactics in making use of the inconsistency and vacillation of US policies, particularly towards the Middle East; its historical experience of interaction with the Muslim cultures, including domestic ones; its geopolitical perception of world politics, and the export of energy resources and military weapons as tools of diplomacy are some of the factors which explain Russian behavior. At the same time, the personal leadership and accumulated experience of President Putin in formulating Russian diplomacy and in manipulating different issues in a combined policy should be taken into account. His initiative in Syria succeeded to some extent in turning world attention away from the Ukrainian issue, aimed at changing the present sanctions imposed by the West. Another phenomenon to be noted in the international arena is the newly developed mutual interaction between Russia and the Arab countries in the Gulf. Frequent visits to Russia by autocratic leaders, including kings, emirsand princes do not always reflect a shared common interest between Russia and the Arab leaders. On the contrary, in spite of sharp and fundamental differences in their attitude toward the issues related to Syria, Iran and Yemen, the Arab leaders find it necessary to communicate with Russia and to know Russia’s expected strategies and intentions towards the Middle East, apart from its oil and gas policies. The Iran deal on the nuclear issue in July 2015 may have been a factor behind the phenomena.