84 research outputs found

    Key factors affecting the technical efficiency of bee farms in the province of La Pampa (Argentina): A two-stage DEA approach

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    This paper analyzes how decision-making, management capacity and technology adoption by beekeepers, affect the technical efficiency (TE) of Argentinean beekeeping through the case study of the province of La Pampa (Argentina). The assessment of TE is currently receiving ever-growing attention as an indicator of sustainability and usage of sufficient natural resources in beekeeping activities. This study aimed to identify the key factors affecting the technical efficiency of bee farms in the province of La Pampa. The study included a sample of 40 bee farms and estimated their TE score through an input-oriented Data Envelopment Analysis (DEA) model. In a second stage, Tobit regression was determined to evaluate the technical inefficiency determinants. This paper found that most beekeeping production units have low TE levels. Only 25 % of bee farms produce either at or close to the frontier. The Tobit model revealed that variables such as marital status, educational level, primary family income, source information usage, planning and health area, affect positively on pure technical efficiency. These results are considered to be of great interest for structured beekeeping systems on small-scale and family farms, as well as for political decision-makers, regarding a public program in apiculture. Highlights: Argentina is the leading country in America, exporting honey worldwide. DEA approach and Tobit model based on a two-stage analysis is a useful tool when evaluating livestock production systems. Bee farmers in La Pampa (Argentina) are operating below the production frontier, which indicates there is still scope for improvement. Variables such as marital status, educational level, primary family income, source information usage, planning and health area, affect positively on technical efficiency. Beekeepers should be encouraged by the government to improve their efficiency through training programs to ease decision-making and management, therefore enhancing productivity.This paper analyzes how decision-making, management capacity and technology adoption by beekeepers, affect the technical efficiency (TE) of Argentinean beekeeping through the case study of the province of La Pampa (Argentina). The assessment of TE is currently receiving ever-growing attention as an indicator of sustainability and usage of sufficient natural resources in beekeeping activities. This study aimed to identify the key factors affecting the technical efficiency of bee farms in the province of La Pampa. The study included a sample of 40 bee farms and estimated their TE score through an input-oriented Data Envelopment Analysis (DEA) model. In a second stage, Tobit regression was determined to evaluate the technical inefficiency determinants. This paper found that most beekeeping production units have low TE levels. Only 25 % of bee farms produce either at or close to the frontier. The Tobit model revealed that variables such as marital status, educational level, primary family income, source information usage, planning and health area, affect positively on pure technical efficiency. These results are considered to be of great interest for structured beekeeping systems on small-scale and family farms, as well as for political decision-makers, regarding a public program in apiculture. Highlights: Argentina is the leading country in America, exporting honey worldwide. DEA approach and Tobit model based on a two-stage analysis is a useful tool when evaluating livestock production systems. Bee farmers in La Pampa (Argentina) are operating below the production frontier, which indicates there is still scope for improvement. Variables such as marital status, educational level, primary family income, source information usage, planning and health area, affect positively on technical efficiency. Beekeepers should be encouraged by the government to improve their efficiency through training programs to ease decision-making and management, therefore enhancing productivity

    Edge-Grafted Molecular Junctions between Graphene Nanoplatelets: Applied Chemistry to Enhance Heat Transfer in Nanomaterials

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    The edge-functionalization of graphene nanoplatelets (GnP) was carried out exploiting diazonium chemistry, aiming at the synthesis of edge decorated nanoparticles to be used as building blocks in the preparation of engineered nanostructured materials for enhanced heat transfer. Indeed, both phenol functionalized and dianiline-bridged GnP (GnP-OH and E-GnP, respectively) were assembled in nanopapers exploiting the formation of non-covalent and covalent molecular junctions, respectively. Molecular dynamics allowed to estimate the thermal conductance for the two different types of molecular junction, suggesting a factor 6 between conductance of covalent vs. non-covalent junctions. Furthermore, the chemical functionalization was observed to drive the self-organization of the nanoflakes into the nanopapers, leading to a 20% enhancement of the thermal conductivity for GnP-OH and E-GnP while the cross plane thermal conductivity was boosted by 150% in the case of E-GnP. The application of chemical functionalization to the engineering of contact resistance in nanoparticles network was therefore validated as a fascinating route for the enhancement of heat exchange efficiency on nanoparticle networks, with great potential impact in low-temperature heat exchange and recovery application

    Bispyrene Functionalization Drives Self-Assembly of Graphite Nanoplates into Highly Efficient Heat Spreader Foils

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    Thermally conductive nanopapers fabricated from graphene and related materials are currently showing great potential in thermal management applications. However, thermal contacts between conductive plates represent the bottleneck for thermal conductivity of nanopapers prepared in the absence of a high temperature step for graphitization. In this work, the problem of ineffective thermal contacts is addressed by the use of bifunctional polyaromatic molecules designed to drive self-assembly of graphite nanoplates (GnP) and establish thermal bridges between them. To preserve the high conductivity associated to a defect-free sp2 structure, non-covalent functionalization with bispyrene compounds, synthesized on purpose with variable tethering chain length, was exploited. Pyrene terminal groups granted for a strong pi-pi interaction with graphene surface, as demonstrated by UV-Vis, fluorescence, and Raman spectroscopies. Bispyrene molecular junctions between GnP were found to control GnP organization and orientation within the nanopaper, delivering significant enhancement in both in-plane and cross-plane thermal diffusivities. Finally, nanopapers were validated as heat spreader devices for electronic components, evidencing comparable or better thermal dissipation performance than conventional Cu foil, while delivering over 90% weight reduction

    Análisis estructural comparativo de las subcuencas lecheras pampeanas

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    The dairy region of La Pampa is divided into three subregions (north, center and south) with different agro-ecological and technological features. These differences warrant a detailed study to differentiate the characteristics of their production systems. The aim of this study was to compare each other's holdings of the three Pampeanassubregions analyzing structural features in order to get a detailed report of the situation to detect strengths and weaknesses, differences and similarities that allow to implement further actions to improve the primary provincial diary sector in an effective and selective way. It was used a stratified random sampling design in districts with proportional allocation, according to the methodology proposed by FAO (Food and Agriculture Organization). The information was collected in 2011 through 56 surveys carried out directly to the producers. 37 variables were analyzed and it was concluded that the Central subregion is the one with the largest diversification into other productions such as agriculture. There is great difference in the size of the farms within each subarea. The central and southern subregions have low stocking rate.The pastoral base of food plus the supplementation of concentrates, pasture rolls and corn silage identify semipastoriles systems prevailing in the Pampeana regions (80%), however the degree of intensification in grazing management and supplements opens a big variety of possibilities with dairy farms that are closer to the stabled and others to the purely pastoral.La cuenca lechera de La Pampa se encuentra dividida en tres subcuencas (norte, centro y sur) con diferentes características agroecológicas y tecnológicas. Estas diferencias ameritan realizar un estudio pormenorizado para diferenciar las características de sus sistemas productivos. El objetivo de este trabajo consistió en comparar entre sí las explotaciones de las tres subcuencas pampeanas analizando características estructurales con el fin de obtener un informe pormenorizado de situación detectando fortalezas y debilidades, diferencias y similitudes que permitan implementar acciones para seguir mejorando de manera efectiva y selectiva el sector primario lechero provincial. Se utilizó un diseño de muestreo aleatorio estratificado por departamentos con asignación proporcional, de acuerdo con la metodología propuesta por la Organización para la Agricultura y la Alimentación (FAO) (Food and Agriculture Organization).La información se recolectó durante el año 2011 en 56 explotaciones mediante encuestas directas al productor. Se analizaron 37 variables y se concluyó que la subcuenca central es la de mayor diversificación hacia otras producciones como la agricultura. Existe una gran variabilidad en la dimensión de las explotaciones dentro de cada subcuenca. Las subcuencas central y sur presentan baja carga animal. La base pastoril de la alimentación más la suplementación de concentrados, rollos de pasturas y silo de maíz identifica los sistemas semipastoriles predominantes en las subcuencas pampeanas (80 %), sin embargo la mayor o menor intensificación en el manejo del pastoreo directo y de los suplementos abre un abanico grande de posibilidades con tambos que se acercan más a los estabulados y otros a los netamente pastoriles DOI:http://dx.doi.org/10.19137/cienvet2013-151

    Eficiencia técnica en los sistemas de producción ganadera bovina del noreste de la provincia de La Pampa

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    Livestock farms in the northeast of La Pampa were c1assified according to their productivity by using a technical efficiency indexoThis objective was achieved, calculating in the first place , the function of production using a lineal regression model with explanatory variables, such as acres of green onion, acres of pasture, total number of animals and costs of supplementation; then the production frontier was calculated.The technical efficiency index (IET) relates the observed value with the potential valué,according to the fol/owing equation IET =VONF = y/yf. Farms were c1assified into high, medium and low efficiency, according the IET. Linking farms by its size (area) and efficiency, the largest number of the same, are observed (16 above 56) .Final/y, with the explanatory variables by univariate ANOVA, farms were distinguished and concluded that the cost of supplementation was the only explanatory of efficiency variable.Livestock farms in the northeast of La Pampa were classified according to their productivity by using a technical efficiency index.This objective was achieved, calculating in the first place, the function of production using a lineal regression model with explanatory variables, such as acres of green onion, acres of pasture, total number of animals and costs of supplementation; then the production frontier was calculated.The technical efficiency index (IET) relates the observed value with the potential value, according to the following equation IET =VO/VF = y/yf. Farms were classified into high, medium and low efficiency, according the IET. Linking farms by its size (area) and efficiency, the largest number of the same, are observed (16 above 56). Finally, with the explanatory variables by univariate ANOVA, farms were distinguished and concluded that the cost of supplementation was the only explanatory of efficiency variable

    La toma de decisiones en las empresas agropecuarias del norte de la provincia de La Pampa

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    The accelerated process of concentration in he Argentine agricultural firms specially affects medium and small productive units. Decapitalization, debts and low productivity prevail nowadays. Different opinions coming from technicians, scientists and firm leaders warn about hazards in firm management. The processing of qualitative information about decision making in agricultural firms in he north of La Pampa province (1995 survey) shows that the majority of managers did not systematize their own firm data, they lacked planning habits and took decisions supported only on mexperienceEl acelerado proceso de concentración de las empresas agropecuarias argentinas afecta especialmente a las unidades productivas medianas y pequeñas de tipo familiar. Este estado de crisis se manifiesta además en descapitalización, endeudamiento y baja productividad de los factores. Opiniones de técnicos, investigadores y dirigentes empresariales, sin dejar de considerar un contexto político y económico no muy favorable, advierten sobre un problema de capacidad en la gestión empresaria del sector. El procesamiento de información cualitativa sobre la forma en que se toman las decisiones en las empresas agropecuarias del norte de la provincia de La Pampa provenientes de una encuesta realizada en el año 1995 indican que la mayoría de los empresarios no sistematizaban la información de su empresa, carecían de hábito planificador y tomaban sus decisiones principalmente basados en la experiencia concordando con las opiniones citada
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