5,551 research outputs found
A social and environmental approach to microfinance credit scoring
Microfinance institutions provide loans to low-income individuals. Their credit scoring systems, if they exist, are strictly financial. Although many institutions consider the social and environmental impact of their loans, they do not incorporate formal systems to estimate these social and environmental impacts. This paper proposes that their creditworthiness evaluations should be coherent with their social mission and, accordingly, should estimate the social and environmental impact of microcredit. Thus, a decision support system to facilitate microcredit granting is proposed using a multicriteria evaluation. The assessment of social impact is performed by calculating the Social Net Present Value. The system captures credit officers'' experience and addresses incomplete and intangible information. The model has been tested in a microfinance institution. The paper shows how a small institution can include social and environmental issues in its decision-making systems to evaluate credit applications. A gap in the preferences was found between members of the board, who are socially driven, and managers and credit officers, who are financially drifted. This mission drift was corrected. The approach followed contributed to creating a culture of social and environmental assessment within the institution, especially among credit officers, thereby translating Microfinance institutions'' social mission into numbers
A note on Verhulst's logistic equation and related logistic maps
We consider the Verhulst logistic equation and a couple of forms of the
corresponding logistic maps. For the case of the logistic equation we show that
using the general Riccati solution only changes the initial conditions of the
equation. Next, we consider two forms of corresponding logistic maps reporting
the following results. For the map x_{n+1} = rx_n(1 - x_n) we propose a new way
to write the solution for r = -2 which allows better precision of the iterative
terms, while for the map x_{n+1}-x_n = rx_n(1 - x_{n+1}) we show that it
behaves identically to the logistic equation from the standpoint of the general
Riccati solution, which is also provided herein for any value of the parameter
r.Comment: 6 pages, 3 figures, 7 references with title
Retos y oportunidades de la implantación de los bancos de agua en España
Con el fin de conseguir una buena gobernanza del agua, que trate de alcanzar un
equilibrio entre los objetivos de eficiencia económica y sostenibilidad ambiental, durante las
últimas décadas se ha potenciado el uso de instrumentos económicos para una mejor
gestión de la demanda de los recursos hídricos, dada la dificultad de seguir aumentando la
oferta de los mismos. En este contexto, este trabajo se centra en los bancos de agua como
mecanismo de mercado que aporta la necesaria flexibilidad institucional en la asignación de
los recursos hídricos entre los diferentes usuarios. La investigación realizada en este sentido
ha permitido desarrollar una tipología de los bancos de agua que actualmente operan a nivel
mundial en base a sus características operativas. Esta caracterización ha permitido
igualmente realizar un análisis crítico de las experiencias de bancos de agua implementadas
hasta la fecha, con el fin poder valorar el desempeño de este instrumento económico para la
mejora de la gestión pública del agua. La investigación llevada a cabo revela que los bancos
de agua son un instrumento útil para la gestión de los recursos hídricos, aportando
sugerencias para la mejora de su implementación operativa en España mediante la
correspondiente reforma de la Ley de Aguas.Ministerio de Economía y Competitividad (MINECO) AGL2013-48080-C2-1-RFondo Europeo de Desarrollo Regional (FEDER) AGL2013-48080-C2-1-
Nuevo material compuesto de matriz geopolimérica activado con ceniza de cascarilla de arroz y KOH: Desempeño a alta temperatura
Geopolymers were produced using an environmentally friendly alkali activator (based on Rice Husk Ash and potassium hydroxide). Aluminosilicates particles, carbon and ceramic fibres were used as reinforcement materials. The effects of reinforcement materials on the flexural strength, linear-shrinkage, thermophysical properties and microstructure of the geopolymers at room and high temperature (1200 ÅãC) were studied. The results indicated that the toughness of the composites is increased 110.4% for geopolymer reinforced by ceramic fibres (G-AF) at room temperature. The presence of particles improved the flexural behaviour 265% for geopolymer reinforced by carbon fibres and particles after exposure to 1200 .C. Linear-shrinkage for geopolymer reinforced by ceramic fibres and particles and the geopolymer G-AF compared with reference sample (without fibres and particles) is improved by 27.88% and 7.88% respectively at 900 ÅãC. The geopolymer materials developed in this work are porous materials with low thermal conductivity and good mechanical properties with potential thermal insulation applications for building applications.Compuestos geopoliméricos fueron producidos usando un activador alcalino alternativo (basado en ceniza de cascarilla de arroz e hidróxido de potasio), partículas aluminosilicatos, fibras de carbono y cerámicas. Se estudió el efecto de fibras y partículas en la resistencia a la flexión, contracción lineal, propiedades termofísicas y microestructura de los geopolímeros a temperatura ambiente y 1200 °C. Los resultados indican que la tenacidad se incrementó 110.4% para el geopolímero reforzado con fibras cerámicas (G-AF) a temperatura ambiente. La presencia de partículas mejora el comportamiento a la flexión 265% para el geopolímero reforzado con fibras de carbono y partículas después de la exposición a 1200 °C. La contracción lineal para el geopolímero reforzado con fibras cerámicas y partículas y el geopolímero G-AF es mejorada 27.88% y 7.88% respectivamente a 900 ºC con respecto al material sin refuerzo. Los materiales geopoliméricos desarrollados en este estudio son materiales porosos de baja conductividad térmica y buenas propiedades mecánicas con potencial aplicación en la industria de la construcción como aislantes térmicos
Trade-off and adaptive cost in a multiple-resistant strain of the invasive potato tuber moth Tecia solanivora
EntomologiaResistance to pesticides is an evolutionary process that entails, in most cases, substantial consequences to the biology of the resistant populations. In this study we focus on the life history traits of the potato tuber moth Tecia solanivora, an invasive and voracious pest for which resistance to pyrethroid insecticides was recently reported. Marginally resistant and multiple‐resistant populations were selected from eight sampled localities in Colombia; the use of a fully susceptible population was not possible since none was recognized in the laboratory or field. The multiple‐resistant Siachoque population exhibited a 42‐fold resistance to the carbamate insecticide carbofuran, and low levels of resistance to chlorpyrifos, a trend observed in six of the eight tested populations. This population also exhibits 24‐fold resistance to permethrin. The marginally resistant population of Gualmatán showed 4‐fold resistance to chlorpyrifos. The multiple-resistant population exhibited a 3.8-day shorter developmental time than the susceptible population, but with higher larval mortality. The peak of egg-laying was delayed in the resistant population in 9 days and the population growth rate was lower than that of the susceptible population.We hypothesize that the short developmental time of the multiple-resistant population may be an adaptation to minimize exposure to insecticides, which are applied to the soil. This adaptation is likely to require the surviving adults to compensate for the smaller nutrient amounts accumulated by the larvae in investing part of its adult life in securing the necessary resources for late-life egg production
The Triple Higgs Boson Self-Coupling at Future Linear e+e- Colliders Energies: ILC and CLIC
We analyzed the triple Higgs boson self-coupling at future
colliders energies, with the reactions . We evaluate the total cross-sections for both and ,
and calculate the total number of events considering the complete set of
Feynman diagrams at tree-level. We vary the triple coupling
within the range and +2. The numerical
computation is done for the energies expected to be available at a possible
Future Linear Collider with a center-of-mass energy and a luminosity 1000 . Our analysis is also extended to a
center-of-mass energy 3 and luminosities of 1000 and 5000
. We found that for the process , the
complete calculation differs only by 3% from the approximate calculation
, while for the process , the expected number of events, considering the decay products of both
and , is not enough to obtain an accurate determination of the triple Higgs
boson self-coupling.Comment: 19 pages, 12 figure
Observations of the Cosmic Microwave Background and Implications for Cosmology and Large Scale Structure
Observations of the Cosmic Microwave Background (CMB) are discussed, with
particular emphasis on current ground-based experiments and on future
satellite, balloon and interferometer experiments. Observational techniques and
the effects of contaminating foregrounds are highlighted. Recent CMB data is
used with large scale structure (LSS) data to constrain cosmological parameters
and the complementary nature of CMB, LSS and supernova distance data is
emphasized.Comment: 23 pages, 10 figures. Phil. Trans. R. Soc. Lond. A., 1998, in pres
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