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.

Lâminas de água salina e doses de adubação orgânica na produção de palma Miúda adensada no semiárido

Cactus pear is an important forage for livestock in semi-arid region of Brazil, due to its adaptation to climate conditions in this region, high productivity and nutritional value. The yield of this cactus has positively responded to techniques such as planting density, fertilization and cutting managements, however, in Rio Grande do Norte State, only certain areas have favorable climate conditions to the development of this crop. Drip irrigation, with a small amount of water, has proven to be an alternative to the viability of cactus pear cultivation in these areas. The research aimed to evaluate the effects of different levels of saline water and manure organic fertilization on the morphological characteristics and production of fresh and dry matter of the prickly-pear cactus cv. Miúda (Nopalea cochenillifera Salm Dick) in a dense planting system. The experiment was conducted at the Experimental Station of Terras Secas (EMPARN), Pedro Avelino, latitude 5°31'21" South and longitude 36°23'14" West. The soil was classified as Typical Cambisol Haplicum Carbonate and the water used in irrigation, C4S1T3 (5,25 dS.m-1), with planting spacing of 2.0 x 0.25 m (20,000 plants ha-1). A completely randomized design in a split plot was used, where water levels (0, 7.5, 15.0 and 30.0 mm month-1) with 10 days intervals, were the main plots and organic fertilization (0 , 25 and 50 Mg ha-1 yr-1) the subplots, with four replicates. The measured morphological characteristics were number of cladodes, height and volume of the plant; length, width, perimeter, thickness, area and cladodes area index, fresh and dry matter production, dry matter content, water use efficiency (WUE) and damage promoted by cochineal pest (Diaspis echinocacti) and soft rot (Erwinia carotovora). There was no influence (P>0.05) of organic fertilization on most variables, particularly in relation to the production of fresh and dry matter. The water levels had a significant influence (P<0.05) on most variables, promoting higher height and volume of the plants, larger and thicker cladodes, and increase on fresh and dry matter production (13.55 Mg DM ha-1 yr-1). The absence of irrigation caused a significant expansion in plant damage caused by the cochineal pest and when irrigated with different water levels there was an increase in damage and stand loss, caused by soft rot, been more intense at the higher water level.

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.

A Fruticultura Irrigada de pequenos produtores no Baixo-Açu: Uma análise da eficiência de custo

This work has as an objective analyze the efficiency of producers costs of the irrigation Project Baixo-Açu , and identify the determining factors of this efficiency. To achieve these targets it was estimated, in a first stage, a frontier of costs by the method, non parametric of Data Envelopment Analysis-DEA, and measured the stakes of efficiency producers. On the second stage, it was utilized the Tobit regression pattern, estimating an inefficiency function of costs, and were indentified the associated factors of resources waste. Among the results found it was noticed the existence of a high waste of resources, that represent more than 54% of effective cost. Among the factors with the highest wastes are: energy, herbicides, defensives and chemical fertilizers. In a general way, the producers presented low efficiency level and, only, two, of seventy-five researched, achieved the frontier of costs minimization. These results reveal, in a certain way, that the producers in irrigated fruit growing in the project Baixo-Açu don t seek to minimize the production costs. It was still noticed, that the reduction of resources waste, and this way the inefficiency of costs, is associated with the agriculturalist education, his experience in agriculture, his access to the technical assistance and credit

Avaliação da eficiência de filtros anaeróbios na remoção de coliformes fecais e ovos de helmintos

The technology of anaerobic reactors for sanitary wastewater treatment has been extensively developed in Brazil, and today it is practically consolidated. They present several advantages, such as low construction and operating costs, and low sludge production, the anaerobic reactors are an attractive alternative to minimize problematic lack of basic sanitation in urban areas, and also of the rural areas. The anaerobic filters have been widely used in Brazil. It produces an effluent with low concentration of organic matter and solids suspended, besides conserving the nutrients, therefore, it is good for use in irrigation, but the practice must be associated with knowledge of the pathogens presence. The main objective of this study was to evaluate the efficiency of anaerobic filters in removal faecal coliforms and helminth eggs, and to verify if the effluent can be used for agricultural purposes, according to the World Organization of Health (WHO, 1989). The protocol used to enumerate helminths eggs was the modified Bailenger method, (Ayres and Mara, 1996) recommended by WHO for evaluation of raw effluent and treated effluent. The membrane filtration method was utilized to determine the concentrations of faecal coliforms. Three different systems of sewer treatment composed by anaerobic filters were analyzed. The results, in a general analysis, showed that all the researched systems reached a larger removal than 93% to helminth eggs, resulting in an effluent with smaller average than 1 egg/L. One of these systems, Sistema RN, reached a larger removal than 99%, confirming the good performance of the anaerobic filters in removal helminths eggs. Even with low concentrations of eggs in the influent, the filters were capable to remove this parameter efficiently. About faecal coliforms, it was observed for all the researched systems an effluent with 106 CFU/100mL. The high concentrations to faecal coliforms in the effluent just allow reuse for restricted irrigation, in agreement with the guidelines of WHO. Although the researched systems have not removed faecal coliforms efficiently, the results indicated a good efficiency of the anaerobic filters in removal helminth eggs

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

Avaliação da eficiência dos programas de pós-graduação acadêmicos em administração, contabilidade e turismo

The Triennial Evaluation of Coordination for the Improvement of Higher Education Personnel (CAPES) is made according to several indicators, divided into several issues and items, and their weights. In these it is evident the importance of scientific periodicals. This study aims to evaluate the relative efficiency of post-graduate students in Business Administration, Accounting and tourism evaluated by CAPES in Brazil. The methodology used the data envelopment analysis - DEA (Data Envelopment Analysis). The data were obtained from the site and organized by the CAPES Qualis score. The analysis was performed by the DEA variable returns to scale, product-oriented (BCC-O), with data from the three-year periods 2004-2006 and 2007-2009. Among the main results are the average increase significantly the relative efficiency of the programs in the period 2007-2009 compared to 2004-2006 period, the highest average efficiency of programs linked to public institutions in relation to private, doctoral programs with the present average efficiency sharply higher than those only with masters, and senior programs in general were more efficient. There is also moderate and significant correlation between the efficiency scores and concepts CAPES. The Malmquist index analysis showed that more than 85% of programs had increased productivity. It is noteworthy that the main effect that influences the increase of the Malmquist index is the displacement of the border (Frontier-shift)

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

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