Bank efficiency in Brazil: the importance for economic sustainability

Studies on efficiency achieved greater relevance in organisations within an open market framework, which in Brazil began around 1990. The objective of this paper, applying the data envelopment analysis methodology, is to analyse the efficiency of banks operating in the country using the database termed 'the biggest banks', periodically divulged by the Central Bank of Brazil in 2010-2012. The methodology was applied to the 26 largest banking organisations via two approaches, one was financial intermediation and the other was results. In the financial intermediation approach, the efficiency increase was the highest among banks specialised in credit from 2010 to 2012. Retail banks, especially the large ones, felt most intensely the reaction of 2011, a year considered as the sector's low performance year. In the results approach, the efficiency increase was higher among retail banks. Factors such as retractions in the SELIC rate and bank spreads impacted all banks, regardless of the segment.

High-efficiency Köhler photovoltaic concentrators with external light confinement

Metal grid lines are a vital element in multijunction solar cells in order to take out from the cell the generated photocurrent. Nevertheless all this implies certain shadowing factor and thus certain reflectivity on cells surface that lowers its light absorption. This reflectivity produces a loss in electrical efficiency and thus a loss in global energy production for CPV systems. We present here an optical design for recovering this portion of reflected light, and thus leading to a system efficiency increase. This new design is based on an external confinement cavity, an optical element able to redirect the light reflected by the cell towards its surface again. It has been possible thanks to the recent invention of the advanced Köhler concentrators by LPI, likely to integrate one of these cavities easily. We have proven the excellent performance of these cavities integrated in this kind of CPV modules offering outstanding results: 33.2% module electrical efficiency @Tcell=25ºC and relative efficiency and Isc gains of over 6%.

High Efficiency Envelope Amplifier based on a Ripple Cancellation Buck Converter. Design, Optimization and Integration in an EER RFPA

Durante los últimos años la tendencia en el sector de las telecomunicaciones ha sido un aumento y diversificación en la transmisión de voz, video y fundamentalmente de datos. Para conseguir alcanzar las tasas de transmisión requeridas, los nuevos estándares de comunicaciones requieren un mayor ancho de banda y tienen un mayor factor de pico, lo cual influye en el bajo rendimiento del amplificador de radiofrecuencia (RFPA). Otro factor que ha influido en el bajo rendimiento es el diseño del amplificador de radiofrecuencia. Tradicionalmente se han utilizado amplificadores lineales por su buen funcionamiento. Sin embargo, debido al elevado factor de pico de las señales transmitidas, el rendimiento de este tipo de amplificadores es bajo. El bajo rendimiento del sistema conlleva desventajas adicionales como el aumento del coste y del tamaño del sistema de refrigeración, como en el caso de una estación base, o como la reducción del tiempo de uso y un mayor calentamiento del equipo para sistemas portátiles alimentados con baterías. Debido a estos factores, se han desarrollado durante las últimas décadas varias soluciones para aumentar el rendimiento del RFPA como la técnica de Outphasing, combinadores de potencia o la técnica de Doherty. Estas soluciones mejoran las prestaciones del RFPA y en algún caso han sido ampliamente utilizados comercialmente como la técnica de Doherty, que alcanza rendimientos hasta del 50% para el sistema completo para anchos de banda de hasta 20MHz. Pese a las mejoras obtenidas con estas soluciones, los mayores rendimientos del sistema se obtienen para soluciones basadas en la modulación de la tensión de alimentación del amplificador de potencia como “Envelope Tracking” o “EER”. La técnica de seguimiento de envolvente o “Envelope Tracking” está basada en la modulación de la tensión de alimentación de un amplificador lineal de potencia para obtener una mejora en el rendimiento en el sistema comparado a una solución con una tensión de alimentación constante. Para la implementación de esta técnica se necesita una etapa adicional, el amplificador de envolvente, que añade complejidad al amplificador de radiofrecuencia. En un amplificador diseñado con esta técnica, se aumentan las pérdidas debido a la etapa adicional que supone el amplificador de envolvente pero a su vez disminuyen las pérdidas en el amplificador de potencia. Si el diseño se optimiza adecuadamente, puede conseguirse un aumento global en el rendimiento del sistema superior al conseguido con las técnicas mencionadas anteriormente. Esta técnica presenta ventajas en el diseño del amplificador de envolvente, ya que el ancho de banda requerido puede ser menor que el ancho de banda de la señal de envolvente si se optimiza adecuadamente el diseño. Adicionalmente, debido a que la sincronización entre la señal de envolvente y de fase no tiene que ser perfecta, el proceso de integración conlleva ciertas ventajas respecto a otras técnicas como EER. La técnica de eliminación y restauración de envolvente, llamada EER o técnica de Kahn está basada en modulación simultánea de la envolvente y la fase de la señal usando un amplificador de potencia conmutado, no lineal y que permite obtener un elevado rendimiento. Esta solución fue propuesta en el año 1952, pero no ha sido implementada con éxito durante muchos años debido a los exigentes requerimientos en cuanto a la sincronización entre fase y envolvente, a las técnicas de control y de corrección de los errores y no linealidades de cada una de las etapas así como de los equipos para poder implementar estas técnicas, que tienen unos requerimientos exigentes en capacidad de cálculo y procesamiento. Dentro del diseño de un RFPA, el amplificador de envolvente tiene una gran importancia debido a su influencia en el rendimiento y ancho de banda del sistema completo. Adicionalmente, la linealidad y la calidad de la señal de transmitida deben ser elevados para poder cumplir con los diferentes estándares de telecomunicaciones. Esta tesis se centra en el amplificador de envolvente y el objetivo principal es el desarrollo de soluciones que permitan el aumento del rendimiento total del sistema a la vez que satisfagan los requerimientos de ancho de banda, calidad de la señal transmitida y de linealidad. Debido al elevado rendimiento que potencialmente puede alcanzarse con la técnica de EER, esta técnica ha sido objeto de análisis y en el estado del arte pueden encontrarse numerosas referencias que analizan el diseño y proponen diversas implementaciones. En una clasificación de alto nivel, podemos agrupar las soluciones propuestas del amplificador de envolvente según estén compuestas de una o múltiples etapas. Las soluciones para el amplificador de envolvente en una configuración multietapa se basan en la combinación de un convertidor conmutado, de elevado rendimiento con un regulador lineal, de alto ancho de banda, en una combinación serie o paralelo. Estas soluciones, debido a la combinación de las características de ambas etapas, proporcionan un buen compromiso entre rendimiento y buen funcionamiento del amplificador de RF. Por otro lado, la complejidad del sistema aumenta debido al mayor número de componentes y de señales de control necesarias y el aumento de rendimiento que se consigue con estas soluciones es limitado. Una configuración en una etapa tiene las ventajas de una mayor simplicidad, pero debido al elevado ancho de banda necesario, la frecuencia de conmutación debe aumentarse en gran medida. Esto implicará un bajo rendimiento y un peor funcionamiento del amplificador de envolvente. En el estado del arte pueden encontrarse diversas soluciones para un amplificador de envolvente en una etapa, como aumentar la frecuencia de conmutación y realizar la implementación en un circuito integrado, que tendrá mejor funcionamiento a altas frecuencias o utilizar técnicas topológicas y/o filtros de orden elevado, que permiten una reducción de la frecuencia de conmutación. En esta tesis se propone de manera original el uso de la técnica de cancelación de rizado, aplicado al convertidor reductor síncrono, para reducir la frecuencia de conmutación comparado con diseño equivalente del convertidor reductor convencional. Adicionalmente se han desarrollado dos variantes topológicas basadas en esta solución para aumentar la robustez y las prestaciones de la misma. Otro punto de interés en el diseño de un RFPA es la dificultad de poder estimar la influencia de los parámetros de diseño del amplificador de envolvente en el amplificador final integrado. En esta tesis se ha abordado este problema y se ha desarrollado una herramienta de diseño que permite obtener las principales figuras de mérito del amplificador integrado para la técnica de EER a partir del diseño del amplificador de envolvente. Mediante el uso de esta herramienta pueden validarse el efecto del ancho de banda, el rizado de tensión de salida o las no linealidades del diseño del amplificador de envolvente para varias modulaciones digitales. Las principales contribuciones originales de esta tesis son las siguientes: La aplicación de la técnica de cancelación de rizado a un convertidor reductor síncrono para un amplificador de envolvente de alto rendimiento para un RFPA linealizado mediante la técnica de EER. Una reducción del 66% en la frecuencia de conmutación, comparado con el reductor convencional equivalente. Esta reducción se ha validado experimentalmente obteniéndose una mejora en el rendimiento de entre el 12.4% y el 16% para las especificaciones de este trabajo. La topología y el diseño del convertidor reductor con dos redes de cancelación de rizado en cascada para mejorar el funcionamiento y robustez de la solución con una red de cancelación. La combinación de un convertidor redactor multifase con la técnica de cancelación de rizado para obtener una topología que proporciona una reducción del cociente entre frecuencia de conmutación y ancho de banda de la señal. El proceso de optimización del control del amplificador de envolvente en lazo cerrado para mejorar el funcionamiento respecto a la solución en lazo abierto del convertidor reductor con red de cancelación de rizado. Una herramienta de simulación para optimizar el proceso de diseño del amplificador de envolvente mediante la estimación de las figuras de mérito del RFPA, implementado mediante EER, basada en el diseño del amplificador de envolvente. La integración y caracterización del amplificador de envolvente basado en un convertidor reductor con red de cancelación de rizado en el transmisor de radiofrecuencia completo consiguiendo un elevado rendimiento, entre 57% y 70.6% para potencias de salida de 14.4W y 40.7W respectivamente. Esta tesis se divide en seis capítulos. El primer capítulo aborda la introducción enfocada en la aplicación, los amplificadores de potencia de radiofrecuencia, así como los principales problemas, retos y soluciones existentes. En el capítulo dos se desarrolla el estado del arte de amplificadores de potencia de RF, describiéndose las principales técnicas de diseño, las causas de no linealidad y las técnicas de optimización. El capítulo tres está centrado en las soluciones propuestas para el amplificador de envolvente. El modo de control se ha abordado en este capítulo y se ha presentado una optimización del diseño en lazo cerrado para el convertidor reductor convencional y para el convertidor reductor con red de cancelación de rizado. El capítulo cuatro se centra en el proceso de diseño del amplificador de envolvente. Se ha desarrollado una herramienta de diseño para evaluar la influencia del amplificador de envolvente en las figuras de mérito del RFPA. En el capítulo cinco se presenta el proceso de integración realizado y las pruebas realizadas para las diversas modulaciones, así como la completa caracterización y análisis del amplificador de RF. El capítulo seis describe las principales conclusiones de la tesis y las líneas futuras. ABSTRACT The trend in the telecommunications sector during the last years follow a high increase in the transmission rate of voice, video and mainly in data. To achieve the required levels of data rates, the new modulation standards demand higher bandwidths and have a higher peak to average power ratio (PAPR). These specifications have a direct impact in the low efficiency of the RFPA. An additional factor for the low efficiency of the RFPA is in the power amplifier design. Traditionally, linear classes have been used for the implementation of the power amplifier as they comply with the technical requirements. However, they have a low efficiency, especially in the operating range of signals with a high PAPR. The low efficiency of the transmitter has additional disadvantages as an increase in the cost and size as the cooling system needs to be increased for a base station and a temperature increase and a lower use time for portable devices. Several solutions have been proposed in the state of the art to improve the efficiency of the transmitter as Outphasing, power combiners or Doherty technique. However, the highest potential of efficiency improvement can be obtained using a modulated power supply for the power amplifier, as in the Envelope Tracking and EER techniques. The Envelope Tracking technique is based on the modulation of the power supply of a linear power amplifier to improve the overall efficiency compared to a fixed voltage supply. In the implementation of this technique an additional stage is needed, the envelope amplifier, that will increase the complexity of the RFPA. However, the efficiency of the linear power amplifier will increase and, if designed properly, the RFPA efficiency will be improved. The advantages of this technique are that the envelope amplifier design does not require such a high bandwidth as the envelope signal and that in the integration process a perfect synchronization between envelope and phase is not required. The Envelope Elimination and Restoration (EER) technique, known also as Kahn’s technique, is based on the simultaneous modulation of envelope and phase using a high efficiency switched power amplifier. This solution has the highest potential in terms of the efficiency improvement but also has the most challenging specifications. This solution, proposed in 1952, has not been successfully implemented until the last two decades due to the high demanding requirements for each of the stages as well as for the highly demanding processing and computation capabilities needed. At the system level, a very precise synchronization is required between the envelope and phase paths to avoid a linearity decrease of the system. Several techniques are used to compensate the non-linear effects in amplitude and phase and to improve the rejection of the out of band noise as predistortion, feedback and feed-forward. In order to obtain a high bandwidth and efficient RFPA using either ET or EER, the envelope amplifier stage will have a critical importance. The requirements for this stage are very demanding in terms of bandwidth, linearity and quality of the transmitted signal. Additionally the efficiency should be as high as possible, as the envelope amplifier has a direct impact in the efficiency of the overall system. This thesis is focused on the envelope amplifier stage and the main objective will be the development of high efficiency envelope amplifier solutions that comply with the requirements of the RFPA application. The design and optimization of an envelope amplifier for a RFPA application is a highly referenced research topic, and many solutions that address the envelope amplifier and the RFPA design and optimization can be found in the state of the art. From a high level classification, multiple and single stage envelope amplifiers can be identified. Envelope amplifiers for EER based on multiple stage architecture combine a linear assisted stage and a switched-mode stage, either in a series or parallel configuration, to achieve a very high performance RFPA. However, the complexity of the system increases and the efficiency improvement is limited. A single-stage envelope amplifier has the advantage of a lower complexity but in order to achieve the required bandwidth the switching frequency has to be highly increased, and therefore the performance and the efficiency are degraded. Several techniques are used to overcome this limitation, as the design of integrated circuits that are capable of switching at very high rates or the use of topological solutions, high order filters or a combination of both to reduce the switching frequency requirements. In this thesis it is originally proposed the use of the ripple cancellation technique, applied to a synchronous buck converter, to reduce the switching frequency requirements compared to a conventional buck converter for an envelope amplifier application. Three original proposals for the envelope amplifier stage, based on the ripple cancellation technique, are presented and one of the solutions has been experimentally validated and integrated in the complete amplifier, showing a high total efficiency increase compared to other solutions of the state of the art. Additionally, the proposed envelope amplifier has been integrated in the complete RFPA achieving a high total efficiency. The design process optimization has also been analyzed in this thesis. Due to the different figures of merit between the envelope amplifier and the complete RFPA it is very difficult to obtain an optimized design for the envelope amplifier. To reduce the design uncertainties, a design tool has been developed to provide an estimation of the RFPA figures of merit based on the design of the envelope amplifier. The main contributions of this thesis are: The application of the ripple cancellation technique to a synchronous buck converter for an envelope amplifier application to achieve a high efficiency and high bandwidth EER RFPA. A 66% reduction of the switching frequency, validated experimentally, compared to the equivalent conventional buck converter. This reduction has been reflected in an improvement in the efficiency between 12.4% and 16%, validated for the specifications of this work. The synchronous buck converter with two cascaded ripple cancellation networks (RCNs) topology and design to improve the robustness and the performance of the envelope amplifier. The combination of a phase-shifted multi-phase buck converter with the ripple cancellation technique to improve the envelope amplifier switching frequency to signal bandwidth ratio. The optimization of the control loop of an envelope amplifier to improve the performance of the open loop design for the conventional and ripple cancellation buck converter. A simulation tool to optimize the envelope amplifier design process. Using the envelope amplifier design as the input data, the main figures of merit of the complete RFPA for an EER application are obtained for several digital modulations. The successful integration of the envelope amplifier based on a RCN buck converter in the complete RFPA obtaining a high efficiency integrated amplifier. The efficiency obtained is between 57% and 70.6% for an output power of 14.4W and 40.7W respectively. The main figures of merit for the different modulations have been characterized and analyzed. This thesis is organized in six chapters. In Chapter 1 is provided an introduction of the RFPA application, where the main problems, challenges and solutions are described. In Chapter 2 the technical background for radiofrequency power amplifiers (RF) is presented. The main techniques to implement an RFPA are described and analyzed. The state of the art techniques to improve performance of the RFPA are identified as well as the main sources of no-linearities for the RFPA. Chapter 3 is focused on the envelope amplifier stage. The three different solutions proposed originally in this thesis for the envelope amplifier are presented and analyzed. The control stage design is analyzed and an optimization is proposed both for the conventional and the RCN buck converter. Chapter 4 is focused in the design and optimization process of the envelope amplifier and a design tool to evaluate the envelope amplifier design impact in the RFPA is presented. Chapter 5 shows the integration process of the complete amplifier. Chapter 6 addresses the main conclusions of the thesis and the future work.

Energy conversion in shape memory alloy heat engine - Part II: Simulation

In this paper, a theoretical model proposed in Part I (Zhu et al., 2001a) is used to simulate the behavior of a twin crank NiTi SMA spring based heat engine, which has been experimentally studied by Iwanaga et al. (1988). The simulation results are compared favorably with the measurements. It is found that (1) output torque and heat efficiency decrease as rotation speed increase; (2) both output torque and output power increase with the increase of hot water temperature; (3) at high rotation speed, higher water temperature improves the heat efficiency. On the contrary, at low rotation speed, lower water temperature is more efficient; (4) the effects of initial spring length may not be monotonic as reported. According to the simulation, output torque, output power and heat efficiency increase with the decrease of spring length only in the low rotation speed case. At high rotation speed, the result might be on the contrary.

Separation and Execution of graphical engine on a cross platform IDE to enhance performance

“Biosim” is a simulation software which works to simulate the harvesting system.This system is able to design a model for any logistic problem with the combination of several objects so that the artificial system can show the performance of an individual model. The system will also describe the efficiency, possibility to be chosen for real life application of that particular model. So, when any one wish to setup a logistic model like- harvesting system, in real life he/she may be noticed about the suitable prostitution for his plants and factories as well as he/she may get information about the least number of objects, total time to complete the task, total investment required for his model, total amount of noise produced for his establishment in advance. It will produce an advance over view for his model. But “Biosim” is quite slow .As it is an object based system, it takes long time to make its decision. Here the main task is to modify the system so that it can work faster than the previous. So, the main objective of this thesis is to reduce the load of “Biosim” by making some modification of the original system as well as to increase its efficiency. So that the whole system will be faster than the previous one and performs more efficiently when it will be applied in real life. Theconcept is to separate the execution part of ”Biosim” form its graphical engine and run this separated portion in a third generation language platform. C++ is chosenhere as this external platform. After completing the proposed system, results with different models have been observed. The results show that, for any type of plants of fields, for any number of trucks, the proposed system is faster than the original system. The proposed system takes at least 15% less time “Biosim”. The efficiency increase with the complexity of than the original the model. More complex the model, more efficient the proposed system is than original “Biosim”.Depending on the complexity of a model, the proposed system can be 56.53 % faster than the original “Biosim”.

A distribuição de riscos em concessões florestais: uma análise econômico-jurídica dos riscos recorrentes do inventário florestal amostral

A Lei 11.284/2006 é um importante marco legal da atividade de gestão florestal do Brasil. O manejo florestal sustentável de florestas públicas, até então exercido exclusivamente pelo Estado, passou a ser passível de concessão com o advento dessa Lei. A chamada “concessão florestal” se insere, portanto, na nova orientação político-econômica brasileira de “desestatização”, privilegiando o princípio da eficiência. Como resultado, a atividade de exploração sustentável de produtos florestais passa a ser transferida pelo Estado, por intermédio do Serviço Florestal Brasileiro, à iniciativa privada. Para o sucesso de uma concessão florestal, os licitantes interessados precisam de uma estimativa da capacidade produtiva da “Unidade de Manejo Florestal”. O estudo disponibilizado pelo Serviço Florestal Brasileiro para fazer essa estimativa é o inventário florestal que, resumidamente, tem a importante missão de antecipar às características vegetais de área que será objeto da concessão. E os resultados desse estudo são a principal fonte de informação para que o licitante calcule o valor que irá ofertar ao Poder Concedente. Ocorre que, por questões técnico-metodológicas que fogem ao conhecimento jurídico, os estudos de inventário florestal estão sujeitos a erros de grande escala, retratando, de maneira ilusória, a realidade da vegetação que compõe área que será concedida. Isto é um risco intrínseco à atividade de exploração sustentável de produtos florestais. Diante desse contexto, caberia ao Serviço Florestal Brasileiro administrar o risco do inventário florestal da maneira mais eficiente possível. Entretanto, não é isso que vem ocorrendo nos contratos de concessão florestal. Sobre a distribuição de riscos em contratos de concessão, a doutrina especializada no tema oferece critérios que, quando seguidos, possibilitam uma alocação dos riscos peculiares a cada atividade à parte que melhor tem condições de geri-los. Esses critérios aumentam a eficiência da concessão. Contudo, os contratos de concessão florestal até hoje celebrados não vêm considerando esses importantes critérios para uma eficiente distribuição de riscos. Como consequência, o risco do inventário florestal é, igualmente a outros inúmeros riscos, negligenciado por esses contratos, aumentando-se a ineficiência dos contratos de concessão. Diante desse panorama, os licitantes interessados na concessão adotam duas posturas distintas, ambas igualmente rejeitáveis: a postura do Licitante Conservador e a postura do Licitante Irresponsável. Esses perfis de licitantes geram, respectivamente, ineficiência à concessão e, caso o erro do inventário florestal efetivamente ocorra, a possibilidade de inviabilidade da concessão. Como resposta a isso – que é exatamente o “problema” que pretendo resolver –, proponho uma solução para melhor administrar o risco do inventário florestal. Essa solução, inspirada em uma ideia utilizada na minuta do contrato de concessão da Linha 4 do Metrô de São Paulo, e baseando-se nos critérios oferecidos pela doutrina para uma distribuição eficiente dos riscos, propõe algo novo: a fim de tornar a os contratos de concessão florestal mais eficientes, sugere-se que o risco do inventário florestal deve ser alocado na Administração Pública, e, caso o evento indesejável efetivamente ocorra (erro do inventário florestal), deve-se, por meio do reequilíbrio econômico-financeiro do contrato, ajustar o valor a ser pago pelo concessionário ao Poder Concedente. Como consequência dessa previsão contratual, as propostas dos licitantes serão mais eficientes, permitindo-se alcançar o objetivo primordial da Lei 11.284/2006: aumento da eficiência da exploração florestal sustentável e preservação do meio ambiente e dos recursos florestais.

The nitrogen sufficiency index underlying estimates of nitrogen fertilization requirements of common bean

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

Aproveitamento da água de umidificação de malte da moagem úmida como matéria prima na fabricação de cerveja

A água de umidificação de malte, resultante da moagem úmida, pode ser usada como matéria prima na fabricação de cerveja. Há, entretanto, cervejarias que descartam esse subproduto, e conseqüentemente, o extrato nele contido. em função disso, o presente trabalho teve por objetivo avaliar a possibilidade de ganho de rendimento na mosturação e alterações nas características químicas e sensoriais da bebida, em virtude do uso dessa água. Cervejas do tipo Pilsen foram produzidas de duas formas: com e sem água de umidificação de malte. Utilizou-se como matéria prima malte, lúpulo, xarope de maltose, água destilada e água de umidificação de malte. O mosto foi produzido pelo processo de infusão, separado do bagaço de malte por filtração convencional e fervido durante 60 minutos. Após seu resfriamento e clarificação o mosto foi inoculado com levedura de baixa fermentação (1,3g/l, ps) e colocado para fermentar a 10°C. A fermentação foi encerrada com 90% da atenuação limite. em seguida, a cerveja foi engarrafada e maturada a 0°C por 14 dias. Os resultados mostraram que o aumento do rendimento de mosturação, em função do uso da água de umidificação de malte, foi estatisticamente não significativo. A utilização dessa água praticamente não alterou as características químicas e sensoriais da cerveja, havendo apenas um leve aumento na intensidade de cor da bebida (7,1 x 8,0 EBC). Considerando, no entanto, que a água de umidificação de malte obtida em nível industrial apresenta maior concentração de extrato em relação àquela produzida em laboratório, espera-se que o uso da primeira traga ganho de rendimento industrial sem alterações significativas nas características da cerveja.

Desenvolvimento de nanopartículas de PLA e PLA-PEG para administração intranasal de zidovudina

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estudo da utilização de biomassa em substituição parcial ao carvão mineral utilizado no processo de fabricação do ferro gusa em alto-forno

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Um estudo sobre a certificação ISO 9001 no Brasil: mapeamento de motivações, benefícios e dificuldades

This work aims to identify the main motivations and difficulties faced by Brazilian companies to obtain ISO 9001 certification. The key quality management practices that provide support to this certification and the relationship with other types of systems, such as ISO 14001 (Environmental Management) and OHSAS 18001 (Occupational Health and Safety Management System), were also investigated. A survey research was conducted with 191 companies. The main motivations for implementing ISO 9001 are the following: internal organization improvement, production efficiency increase, and brand reliability improvement. Employee resistance was the greatest challenge found during the implementation process. On the other hand, the main benefits identified were: quality processes improvement and increased employee awareness of quality. The results reveal that the most common quality programs and tools used are: 5S, brainstorming, and Ishikawa diagram, while the least common are SERVQUAL and QFD.

Modelagem e simulação de ciclos a gás com resfriamento de ar na entrada

The optimization of energy generation systems has become a key issue for technological and social development, mainly in developing countries, where the electricity consumption rises sharply. Gas turbine cycle is an electricity generating system, which studies have demonstrated that inlet air cooling increases net power and thermal efficiency. Thus, this study intends to quantify these parameters for environments with different ambient temperature and relative humidity. Two types of air cooling were used: evaporative and absorption systems. The configuration parameters only with the gas turbine cycle were compared to those whose configuration allowed cooling. First, it was analyzed only evaporative cooling. Next, the absorption system was used for analysis. The last configuration mixed these two methods, dividing equally its flow. The results showed that thermal efficiency and net power increase in any case of cooling, with absorption system more advantageous in terms of generated energy, where an increase between 1 and 2 MW was observed, depending on the ambient conditions . When the two methods were working together at low relative humidity, it showed a thermal efficiency increase compared to absorption system, up to 2.4%. Evaporative cooling was less effective, but it is a good and cheap possibility to increase the cycle parameters at high temperature and low relative humidity

Modelagem e simulação de ciclos a gás com resfriamento de ar na entrada

The optimization of energy generation systems has become a key issue for technological and social development, mainly in developing countries, where the electricity consumption rises sharply. Gas turbine cycle is an electricity generating system, which studies have demonstrated that inlet air cooling increases net power and thermal efficiency. Thus, this study intends to quantify these parameters for environments with different ambient temperature and relative humidity. Two types of air cooling were used: evaporative and absorption systems. The configuration parameters only with the gas turbine cycle were compared to those whose configuration allowed cooling. First, it was analyzed only evaporative cooling. Next, the absorption system was used for analysis. The last configuration mixed these two methods, dividing equally its flow. The results showed that thermal efficiency and net power increase in any case of cooling, with absorption system more advantageous in terms of generated energy, where an increase between 1 and 2 MW was observed, depending on the ambient conditions . When the two methods were working together at low relative humidity, it showed a thermal efficiency increase compared to absorption system, up to 2.4%. Evaporative cooling was less effective, but it is a good and cheap possibility to increase the cycle parameters at high temperature and low relative humidity

The nitrogen sufficiency index underlying estimates of nitrogen fertilization requirements of common bean

Chlorophyll determination with a portable chlorophyll meter can indicate the period of highest N demand of plants and whether sidedressing is required or not. In this sense, defining the optimal timing of N application to common bean is fundamental to increase N use efficiency, increase yields and reduce the cost of fertilization. The objectives of this study were to evaluate the efficiency of N sufficiency index (NSI) calculated based on the relative chlorophyll index (RCI) in leaves, measured with a portable chlorophyll meter, as an indicator of time of N sidedressing fertilization and to verify which NSI (90 and 95 %) value is the most appropriate to indicate the moment of N fertilization of common bean cultivar Perola. The experiment was carried out in the rainy and dry growing seasons of the agricultural year 2009/10 on a dystroferric Red Nitosol, in Botucatu, São Paulo State, Brazil. The experiment was arranged in a randomized complete block design with five treatments, consisting of N managements (M1: 200 kg ha-1 N (40 kg at sowing + 80 kg 15 days after emergence (DAE) + 80 kg 30 DAE); M2: 100 kg ha-1 N (20 kg at sowing + 40 kg 15 DAE + 40 kg 30 DAE); M3: 20 kg ha-1 N at sowing + 30 kg ha-1 when chlorophyll meter readings indicated NSI < 95 %; M4: 20 kg ha-1 N at sowing + 30 kg ha-1 N when chlorophyll meter readings indicated NSI < 90 % and, M5: control (without N application)) and four replications. The variables RCI, aboveground dry matter, total leaf N concentration, production components, grain yield, relative yield, and N use efficiency were evaluated. The RCI correlated with leaf N concentrations. By monitoring the RCI with the chlorophyll meter, the period of N sidedressing of common bean could be defined, improving N use efficiency and avoiding unnecessary N supply to common bean. The NSI 90 % of the reference area was more efficient to define the moment of N sidedressing of common bean, to increase N use efficiency.

Generierung von Konstruktionsmerkmalen zur Entwicklung eines bio-inspirierten Kommissionier- Greifers für die Intralogistik mittels Clusteranalyse

Kurzbeschreibung: In der Automatisierung von intralogistischen Kommissioniervorgängen ist ein großes Zukunftspotential erkennbar. Elementarer Bestandteil des Automatisierungsprozesses ist der Einsatz von Industrierobotern, die mit einem geeigneten Endeffektor, dem Greifer, ausgestattet werden müssen. Die Robotik ist in der Lage schneller, präziser und ausdauernder als die menschlichen Kommissionierer zu arbeiten und trägt damit entscheidend zur Effizienzsteigerung bei. Eine wesentliche Herausforderung für diesen Entwicklungsschritt zur Substitution der manuellen Kommissionierung ist die Konstruktion und Bereitstellung eines geeigneten Greifsystems. Am Lehrstuhl für Maschinenelemente und Technische Logistik der Helmut-Schmidt-Universität wurde mit der Erfahrung aus einem vorangegangenen Forschungsprojekt die Methode der Clusteranalyse erstmalig zur Untersuchung von Greifobjekten zur Entwicklung eines bionischen Universalgreifers für die Kommissionierung von Drogerieartikeln verwendet. Diese Abhandlung beschreibt einen Beitrag zur Entwicklung dieses Greifers am Beispiel handelsüblicher Drogerieartikel, die aktuell manuell kommissioniert werden. Diese werden hinsichtlich der für das Greifen relevanten Objektmerkmale geclustert und die daraus resultierenden Erkenntnisse in Form von Konstruktionsmerkmalen abgeleitet. Nach einer Analyse und Festlegung der greifrelevanten Merkmale der Greifobjekte wird eine Objektdatenbasis erstellt. Mit Hilfe geeigneter Methoden wird die gewonnene Datenbasis aufbereitet und reduziert. Im Anschluss werden die Greifobjekte bzw. deren Merkmalsausprägungen einer hierarchischen Clusteranalyse unterzogen. Hierbei werden die Grenzen der gebildeten Cluster mittels der zugehörigen Greifobjekte festgelegt und analysiert. Abschließend werden bestimmte greiferspezifische Merkmale auf die Anwendbarkeit in den Clustern überprüft und bewertet. Diese Betrachtungen ermöglichen es, dass spezielle Anforderungen an den Greifer, die direkt aus den Eigenschaften der Greifobjekte herrühren, zuverlässig erkannt und konstruktiv berücksichtigt werden können.