Eficiência técnica dos produtores familiares no Projeto de Irrigação do Baixo Açu/RN

SILVA, Jorge Luiz Mariano da. Eficiência técnica dos produtores familiares no projeto de irrigação do Baixo Açu/RN.In: CONGRESSO SA SOCIEDADE BRASILEIRA DE ECONOMIA E SOCIOLOGIA RURAL,42., 2004, Cuiabá - MT. Dinâmcias Setorias e Desevolvimento Regional, 2004.

Eficiência, gestão e meio ambiente na carcinicultura do Rio Grande do Norte

SILVA, J. L. M. da; SAMPAIO, L. M. . Eficiência, Gestão e Meio Ambiente na Carcinicultura do Rio Grande do Norte. In: Congresso da Sociendade Brasileira de Economia, Administração e Sociologia Rural - SOBER, 40., 2007, Londrina. Conhecimentos para a Agricultura do Futuro, 2007.

Análise da eficiência de contratos de serviços de elevada especificidade terceirizados pela petrobras

The definition of the boundaries of the firms is subject that has occupied the organizational theorists long ago, being the seminal work of Coase (1937) indicated as the trigger for one theoretical evolution, with emphasis on governance structures, which led to a modern theory of incomplete contracts. The Transaction Cost Economics (TCE) and Agency Theory arise within this evolution, being widely used in studies related to the theme. Empirically, data envelopment analysis (DEA) has established itself as a suitable tool for analysis of efficiency. Although TCE argues that specific assets must be internalized, recent studies outside the mainstream of theory show that, often, firms may decide, for various reasons, hire them on the market. Researches on transaction costs face with the unavailability of information and methodological difficulties in measuring their critical variables. There`s still the need for further methodological deepening. The theoretical framework includes classic works of TCE and Agency Theory, but also more recent works, outside the mainstream of TCE, which warn about the existence of strategies in use of specific assets that aren`t necessarily aligned with the classical ideas of TCE. The Brazilian oil industry is the focus of this thesis, that aimed to evaluate the efficiency of contracts involving high specificity service outsourced by Petrobras. In order to this, we made the categorization of outsourced services in terms of specificity, as well the description of services with higher specificity. Then, we verified the existence of relationship between the specificity of services and a number of variables, being found divergent results than those that are preached by the mainstream of TCE. Then, we designed a DEA model to analyze the efficiency in the use of onshore drilling rigs, identified among the services of highest specificity. The next step was the application of the model to evaluate the performance of drilling rigs contracts. Finally, we verified the existence of relationship between the efficiency of contracts and a number of variables, being found, again, results not consistent with the theory mainstream. Regarding to analyze of efficiency of drilling rigs contracts, the model developed is compatible with what is found in academic productions in efficiency of drilling rigs. The results on efficiency show a wide range of scores, with efficiencies ranging from 31.79% to 100%, being low the sample efficiency average. There is consonance between the model results and the practices adopted by Petrobras. The results strengthen the DEA as an important tool in studies of efficiency with possibility to use for analysis other types of contracts. In terms of theoretical findings, the results reinforce the arguments that there are situations in which the strategies of the organizations, in terms of use of assets and services of high specificity, do not necessarily follow what is recommended by the mainstream of TCE

Relações interorganizacionais e eficiência coletiva: um estudo de caso no arranjo produtivo local de confecções do agreste pernambucano

This work is a study in the Local Productive Arrangement of confections from Agreste of Pernambuco, as a relevant sector in economic and social aspect. This research has as central aim to understand how the inter-organizational relations influence the collective efficiency of arrangement. The theoretical framework employed highlights the approaches that deal with the benefits of business agglomeration for the develop­ment of firms and regions. It has discussed the approach of small and medium enter­ prises and industrial districts (SCHMITZ, 1997), which introduce the concept of col­ lective efficiency, explaining that only those externalities explained by Marshall (1996) are not sufficient to explain the competitive advantage of enterprises, expand­ing the idea that organizations achieve competitive advantage not acting alone. To examine the influences of relations in the collective efficiency, it has been taken as analytical perspective theory of social networks (GRANOVETTER, 1973, 1985; BURT, 1992; UZZI, 1997) because it has believe that this approach provides subsi­ dies for a structural analysis of social relationships in face the behavior of human ac­tion. By examining the organizations in a social network, you should understand the reason of this establishment of the relationship, their benefits, and as the information flow takes place and density of links between the actors (Powell; SMITH-DOERR, 1994). As for the methods, this study is characterized as a case study, in according to the purposed objectives, in addition to qualitative method. Also, due to recovering of the historical milestones of the arrangement, it is used a sectional approach with longitudinal perspective (VIEIRA, 2004). The primary and secondary data were used in order to understand the evolutionary process of the sector and their inter-actors re­ lationships in the arrangement for the promotion of development, for both, was used the contend and documentary analysis technique, respectively (DELLAGNELO ; SIL­VA, 2005). The approach of social networks has permitted understand that social re­lationships may extend the collective efficiency of the arrangement, and therefore need to develop policies that encourage the legalization of informal companies in ar­rangement, by showing up themselves representative. Thus, the relations estab­ lished in LPA of confections from Agreste of Pernambuco need for more effective mechanisms to broaden the collective efficiency. Therefore, this way as take place has directly benefited only a group of companies that are linked in some way the sup­portive institutions. So we can conclude that the inter-actor relations have limited the collective efficiency of LPA, being stimulated by the institutions in support only to groups of entrepreneurs, even those that produce external relations for all clustered companies

Eficiência e razão de hedge: uma análise dos mercados futuro brasileiros de boi, café, etanol, milho e soja

This research aims to investigate the Hedge Efficiency and Optimal Hedge Ratio for the future market of cattle, coffee, ethanol, corn and soybean. This paper uses the Optimal Hedge Ratio and Hedge Effectiveness through multivariate GARCH models with error correction, attempting to the possible phenomenon of Optimal Hedge Ratio differential during the crop and intercrop period. The Optimal Hedge Ratio must be bigger in the intercrop period due to the uncertainty related to a possible supply shock (LAZZARINI, 2010). Among the future contracts studied in this research, the coffee, ethanol and soybean contracts were not object of this phenomenon investigation, yet. Furthermore, the corn and ethanol contracts were not object of researches which deal with Dynamic Hedging Strategy. This paper distinguishes itself for including the GARCH model with error correction, which it was never considered when the possible Optimal Hedge Ratio differential during the crop and intercrop period were investigated. The commodities quotation were used as future price in the market future of BM&FBOVESPA and as spot market, the CEPEA index, in the period from May 2010 to June 2013 to cattle, coffee, ethanol and corn, and to August 2012 to soybean, with daily frequency. Similar results were achieved for all the commodities. There is a long term relationship among the spot market and future market, bicausality and the spot market and future market of cattle, coffee, ethanol and corn, and unicausality of the future price of soybean on spot price. The Optimal Hedge Ratio was estimated from three different strategies: linear regression by MQO, BEKK-GARCH diagonal model, and BEKK-GARCH diagonal with intercrop dummy. The MQO regression model, pointed out the Hedge inefficiency, taking into consideration that the Optimal Hedge presented was too low. The second model represents the strategy of dynamic hedge, which collected time variations in the Optimal Hedge. The last Hedge strategy did not detect Optimal Hedge Ratio differential between the crop and intercrop period, therefore, unlikely what they expected, the investor do not need increase his/her investment in the future market during the intercrop

A influência de decisões arquitetônicas na eficiência energética do Campus vol. 1/UFRN

Building design is an effective way to achieve HVAC energy consumption reduction. However, this potentiality is often neglected by architects due to the lack of references to support design decisions. This works intends to propose architectural design guidelines for energy efficiency and thermal performance of Campus/UFRN buildings. These guidelines are based on computer simulations results using the software DesignBuilder. The definition of simulation models has begun with envelope variables, partially done after a field study of thirteen buildings at UFRN/Campus. This field study indicated some basic envelope patterns that were applied in simulation models. Occupation variables were identified with temperature and energy consumption monitoring procedures and a verification of illumination and equipment power, both developed at the Campus/UFRN administration building. Three simulation models were proposed according to different design phases and decisions. The first model represents early design decisions, simulating the combination of different types of geometry with three levels of envelope thermal performance. The second model, still as a part of early design phase, analyses thermal changes between circulation halls lateral and central and office rooms, as well as the heat fluxes and monthly temperatures in each circulation hall. The third model analyses the influence of middle-design and detail design decisions on energy consumption and thermal performance. In this model, different solutions of roofs, shading devices, walls and external colors were simulated. The results of all simulation models suggest a high influence of thermal loads due to the incidence of solar radiation on windows and surfaces, which highlights the importance of window shading devices, office room orientation and absorptance of roof and walls surfaces

Análise do custo-benefício de sistemas de cobertas em edificações comerciais para o clima de Natal/RN visando eficiência energética

This research consists in studying the influence of the various type of construction systems of roofs with their energy efficiency as well as on the cost benefit for the commercial buildings on the temperatures condition of the city of Natal/RN. The main goal of this research is to analyze the cost benefit of the construction systems of roofs available on the market, taking into consideration the energy efficiency of the commercial buildings artificially air conditioned in order to be used by the projectors and to be adequated to the temperatures condition of the city of Natal/RN. The method of valuation of the cost benefit of roof systems consists in six steps: Features and simulation of the reference building; Analyze of sensitivity; Analyzes, features and simulation of alternatives of roof construction systems; Analyze of the cost of implementation; Analyze of the benefits of the alternatives comparing to the base case; And finally the analyze of the cost benefit. The model type chosen as reference was stores with pre molded buildings and system of roof with fiber ciment and ceiling . The thermal results showed the influence of the roof system on the energy efficiency of the building. The Final results of the simulations of the alternatives comes to a conclusion that the absortance is the variable that presents the best cost benefit relation and the reduction on the thermal transmittance still has limitations because of the high cost

Qualificação de edifícios residenciais verticais em Natal/RN à luz do regulamento técnico da qualidade para o nível de eficiência energética de edificações residenciais (RTQ-R)

The goal of the research was to investigate the energy performance of residential vertical buildings envelope in the hot and humid climate of Natal, capital of Rio Grande do Norte, based in the Technical Regulation of Quality for Energy Efficiency Level in Residential Buildings (RTQ -R), launched in 2010. The study pretends to contribute to the development of design strategies appropriate to the specific local climate and the increasing of energy efficiency level of the envelope. The methodological procedures included the survey in 22 (twenty two) residential buildings, the formulation of representative prototypes based on typological and constructives characters researched and the classification of the level of energy efficiency in the envelopment of these prototypes, using as a tool the prescriptive method of the RTQ-R and the parametric analyzes from assigning different values of the following variables: shape of the pavement type; distribution of housing compartments; orientation of the building; area and shading of openings; thermal transmittance, and solar absorptance of opaque materials of the frontage in order to evaluate the influence of these on the envelopment performance. The main results accomplished with this work includes the qualification of vertical residential buildings in Natal/RN; the verification of the adequacy of these buildings to local climate based from the diagnosis of the thermal energy of the envelopment performance, the identification of variables with more significant influence on the prescriptive methodology of RTQ-R and design solutions more favorable to obtain higher levels energy efficiency by this method. Finally, it was verified, that some of these solutions proved contradictory in relation to the recommendations contained in the theoretical approaches regarding environmental comfort in hot and humid weather, which indicates the need for improvement of the prescriptive method RTQ-R and further research on efficient design solutions

Estudo do crescimento, eficiência de biofiltração e cinética de absorção de nutrientes (N-NH, N-NO e P-PO4³) da macroalga Gracilaria cervicornis (Turner) J. Agardh

The objective of this study was to examine the growth of Gracilaria cervicornis cultured in a shrimp (Litopenaeus vannamei) pond and to determine the absorption efficiency and the kinetics parameters (Vmax, Ks e Vmax:Ks) of this macroalgae for the nutrients N-NO3-, N-NH4+ and P-PO4-3, aiming at its use as bioremediatory of eutrophicated environments. For this study, two experiments (field and laboratory) were developed. In the field study, the seaweed was examined in relation to the growth and the biomass. In the laboratory experiment, the absorption efficiency of G. cervicornis was measured through the monitoring of the concentration of the three nutrients (N-NO3-, N-NH4+ e P-PO4-3) during 5 hours and the kinetic parameters were determined through the formula of Michaelis-Menten. The results obtained in this study demonstrated that G. cervicornis benefited from the available nutrients in the pond, increasing 52.4% of its biomass value after 30 days of culture. It was evidenced that the variability of the biomass could be explained through the salinity, availability of light (transparency and solid particle in suspension) and concentration of N-NO3- in the environment. In the laboratory experiment, the highest absorption efficiency was found in the treatments with low concentration (5 µmol.L-1), being evidenced a reduction of up to 85,3%, 97,5% and 81,2% of N-NH4+, N-NO3- and P-PO43-, respectively. Regarding the kinetic parameters, G. cervicornis presented better ability in absorbing N-NH4+ in high concentrations (Vmax = 158,5 µmol g-1 dry wt h-1) and P-PO43- in low concentrations (Ks = 5 µmol.L-1 e Vmax:Ks = 10,3). The results of this study show that G. cervicornis could be cultivated in shrimp ponds, presents a good capacity of absorption for the tested nutrients and is a promising candidate for biorremediation in shrimp pond effluent

Síntese e caracterização de NiO-CGO para anodo e eletrólitos sólidos e base de Céria para SOFC

The direct use of natural gas makes the Solid Oxide Fuel Cell (SOFC) potentially more competitive with the current energy conversions technologies. The Intermediate Temperature SOFC (IT-SOFC) offer several advantages over the High Temperature SOFC (HT-SOFC), which includes better thermal compatibility among components, fast start with lower energy consumption, manufacture and operation cost reduction. The CeO2 based materials are alternatives to the Yttria Stabilized Zirconia (YSZ) to application in SOFC, as they have higher ionic conductivity and less ohmic losses comparing to YSZ, and they can operate at lower temperatures (500-800°C). Ceria has been doped with a variety of cations, although, the Gd3+ has the ionic radius closest to the ideal one to form solid solution. These electrolytes based in ceria require special electrodes with a higher performance and chemical and termomechanical compatibility. In this work compounds of gadolinia-doped ceria, Ce1-xGdxO2-δ (x = 0,1; 0,2 and 0,3), used as electrolytes, were synthesized by polymeric precursors method, Pechini, as well as the composite material NiO - Ce0,9Gd0,1O1,95, used as anode, also attained by oxide mixture method, mixturing the powders of the both phases calcinated already. The materials were characterized by X ray diffraction, dilatometry and scanning electronic microscopy. The refinement of the diffraction data indicated that all the Ce1-xGdxO2-δ powders were crystallized in a unique cubic phase with fluorite structure, and the composite synthesized by Pechini method produced smaller crystallite size in comparison with the same material attained by oxide mixture method. All the produced powders had nanometric characteristics. The composite produced by Pechini method has microstructural characteristics that can increase the triple phase boundaries (TPB) in the anode, improving the cell efficiency, as well as reducing the mass transport mechanism effect that provokes anode degradation

Avaliação do efeito de particulados sólidos na eficiência de um inibidor de corrosão recomendado para meios salinos com CO2

The main problem on the exploration activity on petroleum industry is the formation water resulted on the fields producing. The aggravating of this problem is correlated with the advancing technologies used on the petroleum extractions and on its secondary approach objecting the reobtainment of this oil. Among the main contaminants of the water formation are corrosives gases such as: O2, CO2 and H2S, some solids in suspension and dissolved salts. Concerning to those gases the CO2 is the one that produce significant damage for carbon steel on corrosion process of the petroleum and gas industries. Corrosion inhibitors for carbon steel in formation water is one of the most used agents in control of those damages. In this context, the poor investigations of carbon steel corrosion proceeding from solids in suspension is an opened field for studies. On this work the inhibitor effect of the commercial CORRTREAT 703 was evaluated on some specific solids in suspension at saline medium containing 10.000 ppm of de-aerated chloride using CO2 until non oxygen atmosphere been present. For that, quartz, calcium carbonate, magnetite and iron sulphide were subjected to this investigation as the selected solids. The effect of this inhibitor on corrosion process correlated with those specific solids, was measured using electrochemical (resistance of linear polarization and galvanic pair) and gravimetrical techniques. During all the experimental work important parameters were monitored such as: pH, dissolved oxygen, temperature, instantaneous corrosion rate and galvanic current. According to the obtained results it was proved that the suspension solids calcium carbonate and iron sulphide decrease the corrosion process in higher pH medium. Meanwhile the quartz and magnetite been hardness increase corrosion by broking of the passive layer for erosion. In the other hand, the tested inhibitor in concentration of 50 ppm, showed to be effective (91%) in this corrosion process

Desempenho e eficiência biológica de bubalinos de três grupos genéticos terminados em confinamento e abatidos em diferentes estádios de maturidade

Neste trabalho objetivou-se estudar o desempenho e a eficiência biológica de 48 bubalinos (16 Murrah - MUR, 16 Jafarabadi - JAF e 16 Mediterrâneo - MED) com média de 18 meses de idade e de peso vivo inicial de 330 kg terminados em confinamento. Quatro animais de cada grupo genético foram designados por sorteio para o abate inicial e serviram de referência para o estudo dos pesos iniciais de corpo vazio e de carcaça. Os 12 animais restantes de cada grupo genético foram divididos aleatoriamente em três subgrupos de quatro animais e submetidos aos seguintes tratamentos: Maturidade 1 (400 kg PV ao abate); Maturidade 2 (450 kg PV ao abate); Maturidade 3 (500 kg PV ao abate). Foi fornecida uma ração única, ad libitum, para todos os animais, composta por 50% de feno de coastcross na MS e 50% de concentrado à base de fubá de milho, uréia e farelo de soja, devidamente suplementado com minerais. Após os abates pré-fixados, determinou-se o peso corporal vazio (PCVZ) dos animais, por meio do somatório das partes integrantes do corpo. Os consumos médios diários de MS e MO não diferiram entre grupos genéticos, embora animais JAF tenham apresentado os maiores valores numéricos. Animais MUR, JAF e MED não diferiram quanto aos ganhos de peso corporal vazio e de carcaça. Não houve diferenças quanto à eficiência biológica (ganho de peso corporal vazio e ganho de carcaça por unidade de energia metabolizável ingerida) entre os grupos genéticos, embora animais Murrah tenham apresentado os maiores valores. Bubalinos abatidos aos 400 e 450 kg apresentaram melhor eficiência de ganho de peso corporal vazio e ganho de carcaça que os abatidos aos 500 kg.

Eficiência econômica do bicultivo de peixes em viveiros escavados na região paulista do médio Paranapanema

The study assessed the economic efficiency of the pacu with the piacu cultivation in fishponds hollowed in the Middle Paranapanema region, State of São Paulo, 2007/08 crop. It was used the structures of the effective operational cost (EOC) and total operational cost (TOC) and five profitability indicators economic. The TOC per cycle ha(-1) were US$ 12,182.90. The production cost of the pacu and of the piaucu it was US$ 1.20 kg(-1) and US$ 1.40 kg(-1), respectively. The gross income were US$ 17,077.30 ha(-1), operational profit US$ 4,894.30 ha(-1), gross margins 43.8% and profitability rate 30.3%. The break even point 6,125.40 kg ha(-1) for the pacu and 805.90 kg ha(-1) for the piaucu. The viable minimum module corresponded to 0,5 ha of mirror of water. Considering that in the Medium Paranapanema region the medium area of mirror of water for producer is of 0,6 ha, it was ended that this policulture is an alternative of income for enterprising rural regional.

Influência do resíduo de colheita de cana-de-açúcar sem queima sobre a eficiência dos herbicidas imazapic e imazapic + pendimethalin

Os resíduos deixados sobre o solo por ocasião da colheita mecanizada da cana-de-açúcar podem constituir-se em uma barreira física para a ação dos herbicidas no controle de plantas daninhas, quando aplicados em pré-emergência destas plantas sobre a palha da cana. em virtude disso, o presente trabalho teve por objetivos analisar e quantificar a interferência dessa camada de palha sobre o solo na ação dos herbicidas imazapic e imazapic + pendimethalin no controle de plantas daninhas em áreas onde a cana-de-açúcar foi colhida mecanicamente sem a queima da palhada previamente à colheita. Foram realizados dois ensaios simultâneos: um com a retirada da palha dois dias após a aplicação dos herbicidas e o outro com a manutenção desta, ambos conduzidos em casa de vegetação. O imazapic isolado foi aplicado nas dosagens de 0, 122,5 e 147 g i.a.ha-1 e em mistura com pendimethalin na dosagem de 75 + 1500 g i.a.ha-1, com simulação de chuvas nas intensidades de 30, 60 e 90 mm. Após análise dos resultados de biomassa seca, altura e número de folhas das plantas de Sorghum bicolor e Cyperus rotundus, além de nota visual e biomassa seca de Panicum maximum, Brachiaria plantaginea, Digitaria horizontalis, Amaranthus viridis, Ipomoea grandifolia e Brachiaria decumbens, constatou-se eficiência proporcional dos herbicidas à dosagem utilizada, independentemente da presença da palha, à exceção de Ipomoea grandifolia e Brachiaria decumbens, além de haver menor controle nos tratamentos submetidos à chuva de 90 mm. Esses resultados indicam boas perspectivas quanto à aplicação destes herbicidas em áreas de colheita mecanizada de cana-de-açúcar sem queima, para controle de plantas daninhas em condições de pré-emergência.

Efeitos da aplicação de herbicidas sobre a eficiência fotoquímica em plantas de soja convencional e geneticamente modificada

Objetivou-se, neste trabalho, avaliar o efeito da aplicação de herbicidas em pós-emergência sobre a eficiência fotoquímica de duas cultivares de soja (M-SOY 7908 RR e M-SOY 8001). O delineamento experimental utilizado foi em blocos ao acaso, com quatro repetições. Os tratamentos constaram da aplicação de herbicidas isolados e em misturas: lactofen, glyphosate, lactofen + chlorimuron-ethyl, chlorimuron-ethyl + imazethapyr, chlorimuron-ethyl + bentazon, glyphosate + imazethapyr, lactofen + chlorimuron-ethyl + imazethapyr e lactofen + chlorimuron-ethyl + imazethapyr/haloxyfop-methyl. Além disso, foram mantidas duas testemunhas sem aplicação de herbicida. As avaliações foram realizadas aos 4; 11; 18; 25 e 32 dias após aplicação dos herbicidas (DAA) no primeiro ano, e aos 6, 14, 21, 28 e 35 DAA, no segundo. A cultivar M-SOY 8001 foi suscetível à aplicação dos herbicidas, principalmente às misturas contendo lactofen + chlorimuron-ethyl e lactofen + chlorimuron-ethyl + imazethapyr + haloxifop-methyl, os quais provocaram redução no rendimento quântico máximo do PSII (Fv/Fm). As duas cultivares apresentaram suscetibilidade aos herbicidas quando tratados com lactofen aplicado isolado e nas misturas lactofen + chlorimuron-ethyl, chlorimuron-ethyl + imazethapyr, lactofen + chlorimuron-ethyl + imazethapyr e lactofen + chlorimuron-ethyl + imazethapyr + haloxifop-methyl com redução nos teores de clorofila, estimados pelo Medidor Portátil de Clorofilas. Os danos foram reversíveis, desaparecendo gradativamente com a idade das plantas.