Estudo comparativo do desgaste de ferramentas cerâmicas de Al2O3 em relação às de B4C + TiB2

Due to the high value of the bill that the Brazilian has been paying, one of the most expensive in the world, is becoming increasingly attractive the option for renewable energy in form of distributed micro and minigeneration. In other words, the renewable energy sources are becoming attractive not only because of environmental concerns, but also due to economic issues. This has become even more relevant and concrete after approval of rules by National Agency of Electric Energy (ANEEL) on 4/17/2012 (Normative Resolution n ° 482/2012 of 04/17/2012) aimed at reducing barriers to installation of small distributed generation, including microgeneration, with up to 100 kW of power, and minigeneration, 100 kW to 1 MW. The Normative Resolution n ° 482/2012 creates the Energy Clearing System, which allows consumers to install small generators in its consumer unit and exchange energy with the local distributor. The rule applies to generators that use renewable sources of energy (hydro, solar, biomass, wind and cogeneration qualified). In this context, this paper presents a technical and economic analysis of installing a residential microgenerating plant composed of photovoltaic cells, solar panels and small wind turbines

Impacto da construção de Pequenas Centrais Hidrelétricas (PCHs) sobre a comunidade de macroinvertebrados aquáticos associados a pedrais: um estudo de caso no rio Sapucaí-Mirim (SP)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Modelagem do aporte de sedimentos aplicada à bacia hidrográfica contribuinte da PCH Costa Rica (MS) e proposta de mitigação do assoreamento

Pós-graduação em Engenharia Mecânica - FEG

Biodiversidade dos parasitas de peixes provenientes do rio Sapucaí-Mirim, Estado de São Paulo, Brasil

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

Moving along the mental number line: Interactions between whole-body motion and numerical cognition

Active head turns to the left and right have recently been shown to influence numerical cognition by shifting attention along the mental number line. In the present study, we found that passive whole-body motion influences numerical cognition. In a random-number generation task (Experiment 1), leftward and downward displacement of participants facilitated small number generation, whereas rightward and upward displacement facilitated the generation of large numbers. Influences of leftward and rightward motion were also found for the processing of auditorily presented numbers in a magnitude-judgment task (Experiment 2). Additionally, we investigated the reverse effect of the number-space association (Experiment 3). Participants were displaced leftward or rightward and asked to detect motion direction as fast as possible while small or large numbers were auditorily presented. When motion detection was difficult, leftward motion was detected faster when hearing small number and rightward motion when hearing large number. We provide new evidence that bottom-up vestibular activation is sufficient to interact with the higher-order spatial representation underlying numerical cognition. The results show that action planning or motor activity is not necessary to influence spatial attention. Moreover, our results suggest that self-motion perception and numerical cognition can mutually influence each other.

Automatic fault detection on BIPV systems without solar irradiation data

BIPV systems are small PV generation units spread out over the territory, and whose characteristics are very diverse. This makes difficult a cost-effective procedure for monitoring, fault detection, performance analyses, operation and maintenance. As a result, many problems affecting BIPV systems go undetected. In order to carry out effective automatic fault detection procedures, we need a performance indicator that is reliable and that can be applied on many PV systems at a very low cost. The existing approaches for analyzing the performance of PV systems are often based on the Performance Ratio (PR), whose accuracy depends on good solar irradiation data, which in turn can be very difficult to obtain or cost-prohibitive for the BIPV owner. We present an alternative fault detection procedure based on a performance indicator that can be constructed on the sole basis of the energy production data measured at the BIPV systems. This procedure does not require the input of operating conditions data, such as solar irradiation, air temperature, or wind speed. The performance indicator, called Performance to Peers (P2P), is constructed from spatial and temporal correlations between the energy output of neighboring and similar PV systems. This method was developed from the analysis of the energy production data of approximately 10,000 BIPV systems located in Europe. The results of our procedure are illustrated on the hourly, daily and monthly data monitored during one year at one BIPV system located in the South of Belgium. Our results confirm that it is possible to carry out automatic fault detection procedures without solar irradiation data. P2P proves to be more stable than PR most of the time, and thus constitutes a more reliable performance indicator for fault detection procedures. We also discuss the main limitations of this novel methodology, and we suggest several future lines of research that seem promising to improve on these procedures.

Viabilidade ambiental na implantação de pequenas centrais hidrelétricas, por meio de um estudo de caso no alto da bacia hidrográfica do rio Jacaré-Guaçu/SP

Em virtude da perspectiva de exploração do potencial em Pequenas Centrais Hidrelétricas como complemento energético a ser utilizado como alternativa para atendimento de demandas localizadas, discute-se neste trabalho a viabilidade ambiental de sua implantação, bem como dos fatores ambientais intervenientes nesse processo. Partindo-se do pressuposto que, no caso das PCHs, as implicações ambientais apresentam especificidade própria e que não podem ser tratadas da mesma forma que os grandes aproveitamentos, busca-se com esse estudo contemplar os principais fatores a serem considerados no processo de tomada de decisão para que haja uma melhor integração entre o empreendimento e o meio onde será inserido. Nesse contexto são produzidos cartas e documentos com a identificação dos fatores ambientais preponderantes, bem como a análise de alternativas locacionais e os impactos decorrentes pela construção de barragens com base em suas diferentes alturas.

Localização de usinas termoelétricas utilizando Sistema de Informação Geográfica e métodos de decisão multicritério

No setor de energia elétrica, a área que se dedica ao estudo da inserção de novos parques geradores de energia no sistema é denominada planejamento da expansão da geração. Nesta área, as decisões de localização e instalação de novas usinas devem ser amplamente analisadas, a fim de se obter os diversos cenários proporcionados pelas alternativas geradas. Por uma série de fatores, o sistema de geração elétrico brasileiro, com predominância hidroelétrica, tende a ser gradualmente alterada pela inserção de usinas termoelétricas (UTEs). O problema de localização de UTEs envolve um grande número de variáveis através do qual deve ser possível analisar a importância e contribuição de cada uma. O objetivo geral deste trabalho é o desenvolvimento de um modelo de localização de usinas termoelétricas, aqui denominado SIGTE (Sistema de Informação Geográfica para Geração Termoelétrica), o qual integra as funcionalidades das ferramentas SIGs (Sistemas de Informação Geográfica) e dos métodos de decisão multicritério. A partir de uma visão global da área estudada, as componentes espaciais do problema (localização dos municípios, tipos de transporte, linhas de transmissão de diferentes tensões, áreas de preservação ambiental, etc.) podem ter uma representação mais próxima da realidade e critérios ambientais podem ser incluídos na análise. Além disso, o SIGTE permite a inserção de novas variáveis de decisão sem prejuízo da abordagem. O modelo desenvolvido foi aplicado para a realidade do Estado de São Paulo, mas deixando claro a viabilidade de uso do modelo para outro sistema ou região, com a devida atualização dos bancos de dados correspondentes. Este modelo é designado para auxiliar empreendedores que venham a ter interesse em construir uma usina ou órgãos governamentais que possuem a função de avaliar e deferir ou não a licença de instalação e operação de usinas.

Proposta de uma matriz de decisão em energia hidrelétrica com o uso do método multicritério, para formulação de políticas públicas no estado do Paraná

Brazil is internationally acknowledged for its renewable sources, most notably, hydroelectric power plant projects which correspond to 65% of electricity production supply to the National Interconnected System. The main question behind this research is: what are the weights and the relative importance of the variables which have influence on the decision making process for the expansion of hydroelectric generation projects in Parana? The main objective is to propose a multi-criteria decision procedure, in association with water sources options that take into consideration the weight and relative importance of the alternatives having influence on the decision by enterprises in the generation of electricity in the state of Paraná. As far as the approach to the problem is concerned, this research can be classified as having mixed methodologies, applying Content Analysis, Delphi technique and the Analytic Hierarchy Process. Following Delphi methodology, a group of 21 was selected for data collection, all of those linked to Paranaense hydroelectricity market. And the main result was the construction of a decision tree in which it was possible to identify the importance and relative weight of the elements associated with the four dimensions of energy. In environmental dimension, the highest relative weight was placed on the loading capacity of Parana system; the economic dimension, the amortization of investment; in social dimension, the generation of direct work places and in institutional dimension, the availability of suitable sources of financing. Policy makers and business managers make their decisions based on specific criteria related to the organization segment, market information, economic and political behavior among other indicators that guide them in dealing with the typical tradeoffs of projects in hydropower area. The results obtained in the decision tree show that the economic bias is still the main factor in making investment decisions. However, environmental impacts on the State loading capacity, income generation, providing opportunities for direct as well as indirect jobs. And at an institutional level, the absence of funding sources show that the perception of experts is focused on other issues beyond the logic behind development per se. The order of priority of variables in this study indicates that in the current environment of uncertainty in the Brazilian economy as many variables must be analyzed and compared in order to optimize the scarce resources available to expand local development in relation to Paranaense water matrix.

Generation and characterisation of Cisplatin-resistant non-small cell lung cancer cell lines displaying a stem-like signature

Introduction: Inherent and acquired cisplatin resistance reduces the effectiveness of this agent in the management of non-small cell lung cancer (NSCLC). Understanding the molecular mechanisms underlying this process may result in the development of novel agents to enhance the sensitivity of cisplatin. Methods: An isogenic model of cisplatin resistance was generated in a panel of NSCLC cell lines (A549, SKMES-1, MOR, H460). Over a period of twelve months, cisplatin resistant (CisR) cell lines were derived from original, age-matched parent cells (PT) and subsequently characterized. Proliferation (MTT) and clonogenic survival assays (crystal violet) were carried out between PT and CisR cells. Cellular response to cisplatin-induced apoptosis and cell cycle distribution were examined by FACS analysis. A panel of cancer stem cell and pluripotent markers was examined in addition to the EMT proteins, c-Met and β-catenin. Cisplatin-DNA adduct formation, DNA damage (γH2AX) and cellular platinum uptake (ICP-MS) was also assessed. Results: Characterisation studies demonstrated a decreased proliferative capacity of lung tumour cells in response to cisplatin, increased resistance to cisplatin-induced cell death, accumulation of resistant cells in the G0/G1 phase of the cell cycle and enhanced clonogenic survival ability. Moreover, resistant cells displayed a putative stem-like signature with increased expression of CD133+/CD44+cells and increased ALDH activity relative to their corresponding parental cells. The stem cell markers, Nanog, Oct-4 and SOX-2, were significantly upregulated as were the EMT markers, c-Met and β-catenin. While resistant sublines demonstrated decreased uptake of cisplatin in response to treatment, reduced cisplatin-GpG DNA adduct formation and significantly decreased γH2AX foci were observed compared to parental cell lines. Conclusion: Our results identified cisplatin resistant subpopulations of NSCLC cells with a putative stem-like signature, providing a further understanding of the cellular events associated with the cisplatin resistance phenotype in lung cancer. © 2013 Barr et al.

Benefits and risks of large hydrostatic recesses in hydroelectric turbine thrust bearings

Operators of hydroelectric power stations sometimes call upon engineers to modify existing hydroelectric turbines, usually several decades old, for improved maintainability and reliability. One common modification is the hybridisation of plain thrust pads to allow hydrostatic operation to reduce the risk of bearing wipe at low speed (virtually all new installations benefit from this feature). A modification such as this is not a difficult undertaking; however, there are numerous factors that need to be considered in order to maximize bearing performance. One factor that stands out above the others is whether the thrust bearing should be designed to lift the turbine immediately from the standing condition, which presents an interesting challenge: the recess has to have a sufficiently large area in order for the supply pressure to be able to overcome the dead weight of the turbine. If the combination of groove area and pressure is insufficient, then lifting is neither immediate nor guaranteed. This need not be a significant problem, as the bearings have exhibited adequate performance even in the absence of a hydrostatic lubricant supply. A case study is presented whereby relatively large hydrostatic recesses are added to the pads of thrust bearing. It is demonstrated with the aid of simple numerical modelling that the impact of the recess relative to the original pad is small under normal operating conditions. Most surprising, however, is that significant reductions in average oil film temperature and power dissipation are predicted.

"Small-particle limit" the second harmonic generation from noble metal nanoparticles

In this paper, we have probed the origin of SHG in copper nanoparticles by polarization-resolved hyper-Rayleigh scattering (HRS). Results obtained with various sizes of copper nanoparticles at four different wavelengths covering the wavelength range 738-1907 nm reveal that the origin of second harmonic generation (SHG) in these particles is purely dipolar in nature as long as the size (d) of the particles remains smaller compared to the wavelength (;.) of light ("small-particle limit"). However, contribution of the higher order multipoles coupled with retardation effect becomes apparent with an increase in the d/lambda ratio. We have identified the "small-particle limit" in the second harmonic generation from noble metal nanoparticles by evaluating the critical d/lambda ratio at which the retardation effect sets in the noble metal nanoparticles. We have found that the second-order nonlinear optical property of copper nanoparticles closely resembles that of gold, but not that of silver. (C) 2009 Elsevier B.V. All rights reserved.

Hydroelectric Voltage Generation Based On Water-Filled Single-Walled Carbon Nanotubes

A DFT/MD mutual iterative method was employed to give insights into the mechanism of voltage generation based on water-fitted single-walled carbon nanotubes (SWCNTs). Our calculations showed that a constant voltage difference of several mV would generate between the two ends of a carbon nanotube, due to interactions between the water dipole chains and charge carriers in the tube. Our work validates this structure of a water-fitted SWCNT as a promising candidate for a synthetic nanoscale power cell, as well as a practical nanopower harvesting device at the atomic level. 

Placement of Small Vertical Axis Wind Turbine to Maximize Power Generation Influenced by Architectural and Geographic Interfaces in Urban Areas

Current methods for large-scale wind collection are unviable in urban areas. In order to investigate the feasibility of generating power from winds in these environments, we sought to optimize placements of small vertical-axis wind turbines in areas of artificially-generated winds. We explored both vehicular transportation and architecture as sources of artificial wind, using a combination of anemometer arrays, global positioning system (GPS), and weather report data. We determined that transportation-generated winds were not significant enough for turbine implementation. In addition, safety and administrative concerns restricted the implementation of said wind turbines along roadways for transportation-generated wind collection. Wind measurements from our architecture collection were applied in models that can help predict other similar areas with artificial wind, as well as the optimal placement of a wind turbine in those areas.

Generation of macroscopic superposition states with small nonlinearity

We suggest a scheme to generate a macroscopic superposition state ("Schrodinger cat state") of a free-propagating optical field using a beam splitter, homodyne measurement, and a very small Kerr nonlinear effect. Our scheme makes it possible to reduce considerably the required nonlinear effect to generate an optical cat state using simple and efficient optical elements.