Gypsum scarps and asymmetric fluvial valleys in evaporitic terrains. The role of river migration, landslides, karstification and lithology (Ebro River, NE Spain)

Most of the Spanish fluvial systems excavated in Tertiary evaporitic gypsum formations show asymmetric valleys characterized by a stepped sequence of fluvial terraces on one valley flank and kilometric-long and > 100-m high prominent river scarp on the opposite side of the valley. Scarp undermining by the continuous preferential lateral migration of the river channel toward the valley margin leads to vertical to overhanging unstable slopes affected by a large number of slope failures that become the main geological hazard for villages located at the toe of the scarps. Detailed mapping of the gypsum scarps along the Ebro and Huerva Rivers gypsum scarps demonstrates that landslides and lateral spreading processes are predominant when claystones crop out at the base of the scarp, while rockfalls and topples become the dominant movement in those reaches where the rock mass is mainly constituted by evaporites. The dissolution of gypsum nodules, seasonal swelling and shrinking, and dispersion processes contribute to a decrease in the mechanical strength of claystones. The existence of dissolution-enlarged joints, sinkholes, and severely damaged buildings at the toe of the scarp from karstic subsidence demonstrates that the interstratal karstification of evaporites becomes a triggering factor in the instability of the rock mass. The genesis of asymmetric valleys and river gypsum scarps in the study area seem to be caused by the random migration of the river channel in the absence of lateral tilting related to tectonics or dissolution-induced subsidence. Once the scarp is developed, its preservation depends on the physicochemical properties of the substratum, the ratio between bedrock erosion and river incision rates, and climatic conditions that favour runoff erosion versus dissolution

Carbon footprint of dairy goat production systems: A comparison of three contrasting grazing levels in the Sierra de Grazalema Natural Park (Southern Spain)

The main objective of this study was to analyze the carbon footprint (CF) of grazing dairy goat systems in a natural park according to their grazing level. A total of 16 representative grazing goat farms in southern Spain were selected and grouped into three farming systems: low productivity grazing farms (LPG), more intensified grazing farms (MIG) and high productivity grazing farms (HPG). Their CF was analyzed, including greenhouse gas emissions and soil C sequestration according to the farms’ grazing level and milk productivity, taking into account different functional units (one kilogram of fat and protein corrected milk (FPCM) and one hectare) and milk correction. Results showed that all variables differed according to the milk correction applied as the values for cow's milk correction were 41% lower than for sheep's milk correction. Total emissions and contributions of soil carbon sequestration differed according to farming system group; LPG farms had higher total emissions than MIG and HPG farms, however total carbon sequestration was lower in the MIG farms than in the LPG and HPG farms. The CF values ranged from 2.36 to 1.76 kg CO2e kg⁻¹ FPCM for sheep's milk correction and from 1.40 to 1.04 kg CO2e kg⁻¹ FPCM for cow's milk correction. No differences were found between farming system groups in either of the two cases but when calculations took hectare of land as a functional unit, the contribution of MIG farms to the CF was 85% higher than LPG and HPG farms. Therefore it is important to take into account the functional unit used to calculate the CF by analyzing this indicator in a broader context, and including carbon sequestration by grazing livestock in the calculation. In order to reduce the CF of this type of system, it is advisable to make appropriate use of the natural resources and to reach an optimum level of milk productivity, high enough for pastoral livestock farming to be viable

Energy Assessment of Pastoral Dairy Goat Husbandry from an Agroecological Economics Perspective. A Case Study in Andalusia (Spain)

This paper presents a methodological proposal of new energy sustainability indicators according to a novel accounting that follows agroecological and ecological economics criteria. Energy output is reformulated to include manure and thus consider the contribution to fertilization made by pastoral livestock farming to agroecosystems. Energy inputs calculations include the grazing resources. These new definitions and calculations allow for new formulations of the energy return on investment (EROI) as measures of the energy efficiency of livestock farming systems (final EROI and food/feed EROI). The environmental benefit of manure is estimated from the avoided energy cost of using this alternative to inorganic fertilizers (AECM). The environmental benefit of grazing is measured through the energy cost of avoiding cultivated animal feed (AECP) and its impact in terms of non-utilized agricultural area (ALCP). The comparative analysis of different livestock breeding systems in three pastoral dairy goat farms in the Sierra de Cádiz in Andalusia, southern Spain, reveals the analytical potential of the new energy sustainability indicators proposed, as well as the potential environmental benefits derived from territorial-based stockbreeding and, more specifically, grazing activities. Those benefits include gains in energy efficiency, a reduction of the dependence on non-renewable energy, and environmental costs avoided in terms of energy in extensive pastoral systems

Plan de gestión integral de residuos hospitalarios y similares en su componente interno para la secretaria de salud de Pereira

El presente documento expone una propuesta para la Gestión Integral de los Residuos Hospitalarios y Similares –GRHS en la Secretaría de Salud y Seguridad Social del Municipio de Pereira en su componente interno, de manera que permita responder a la necesidad de contar con un instrumento orientador para el manejo de los residuos que se generan en el desarrollo de sus actividades de salud pública y salud ambiental. Dentro de la gestión integral de residuos hospitalarios, este se puede abordar desde los aspectos internos y externos, en el caso particular de este trabajo, se orienta al componente interno, ya que la condición de Secretaría, garantiza de la interrelación administrativa con organizaciones legalmente constituidas y reconocidas para las labores especiales; la prioridad de este estudio, es fundamentar algunas acciones, que presentan dificultades al interior de la institución. El Plan de Gestión Integral de Residuos Hospitalarios y Similares en su componente interno está orientado a optimizar los recursos, mitigar los impactos y contribuir al cambio en la cultura en el manejo de los residuos generados por esta entidad que ejerce la rectoría, control y evaluación en la prestación de los servicios de promoción de la salud y prevención de la enfermedad. Para el desarrollo del documento se partió de trabajo mancomunado con los funcionarios de la Secretaría de Salud. De esta manera se conoció la estructura y funcionamiento operativo de esta entidad. De igual manera se identificaron los programas con los que se atiende a la comunidad y el uso de materiales en los servicios de salud, incluidas las acciones de promoción de la salud, prevención de la enfermedad donde se generan residuos que se deben trabajar de manera responsable. El reconocimiento general de este tipo de residuos y la identificación de sus características, conllevan a la consolidación de una serie de actividades que permitan manejar dentro de las instalaciones de la Institución los diversos tipos de desechos, los cuales no cuentan en la actualidad con el espacio técnicamente definido para su almacenamiento, situación crítica en las instalaciones actuales de la secretaría. Por último y atendiendo la responsabilidad de la Secretaría con las personas encargadas del manejo de los RHS, se establecen unos criterios de seguridad que corresponden a indumentaria necesaria para mantener la integridad de los trabajadores

Transverse Takahashi Identities and Their Implications for Gauge Independent Dynamical Chiral Symmetry Breaking

In this article, we employ transverse Takahashi identities to impose valuable non-perturbative constraints on the transverse part of the fermion-photon vertex in terms of new form factors, the so called $Y_i$ functions. We show that the implementation of these identities is crucial in ensuring the correct local gauge transformation of the fermion propagator and its multiplicative renormalizability. Our construction incorporates the correct symmetry properties of the $Y_i$ under charge conjugation operation as well as their well-known one-loop expansion in the asymptotic configuration of incoming and outgoing momenta. Furthermore, we make an explicit analysis of various existing constructions of this vertex against the demands of transverse Takahashi identities and the previously established key features of quantum electrodynamics, such as gauge invariance of the critical coupling above which chiral symmetry is dynamically broken. We construct a simple example in its quenched version and compute the mass function as we vary the coupling strength and also calculate the corresponding anomalous dimensions $\gamma_m$. There is an excellent fit to the Miransky scalling law and we find $\gamma_m=1$ rather naturally in accordance with some earlier results in literature, using arguments based on Cornwall-Jackiw-Tomboulis effective potential technique. Moreover, we numerically confirm the gauge invariance of this critical coupling.Comment: 16 pages, 4 figure

Estudio de fallas de motores eléctricos en Costa Rica

Proyecto de Investigación Instituto Tecnológico de Costa Rica. Vicerrectoría de Investigación y Extensión (VIE). Escuela de Ingeniería Electromecánica, 2009El proyecto se centró en conocer e identificar aspectos específicos relacionados con las fallas en los motores y su grado de incidencia, a saber: 1. Falta de conciencia en el control y seguimiento de fallas de motores. 2. En las empresas visitadas existe ausencia de registro de las fallas más comunes a nivel nacional, que considere aspectos propios de las industrias de nuestro país. 3. Existe una mejor organización de la información en algunos talleres de reparación de motores eléctricos. 4. Indisponibilidad del personal calificado y del equipo técnico, para el análisis de las fallas de los equipos. 5. No hay (o se aplican insuficientemente) criterios adecuados para la selección de motores. 6. Falta de regulación a los talleres en cuanto a la forma de reparar motores, no hay quien los certifique ni regule técnicamente los trabajos realizados. 7. Inexistencia de medidas predictivas y preventivas posteriores a la reparación del motor eléctrico

The impact of groundwater drawdown and vacuum pressure on sinkhole development. Physical laboratory models

A considerable proportion of the damaging sinkholes worldwide correspond to human-induced subsidence events related to groundwater withdrawal and the associated water-table decline (e.g. aquifer overexploitation, dewatering for mining). Buoyancy loss in pre-existing cavity roofs is generally claimed to be the main underlying physical mechanism. It has been also postulated that rapid water-table drawdowns may create a vacuum effect in the subsurface and contribute to enhance sinkhole activity in karstic terrains with a low effective porosity cover. Our laboratory physical model explores the role played by vacuum pressure induced water-table drops with different magnitudes and rates on sinkhole development, simulating an invariable mantled karst comprising cavernous bedrock and a low-permeability cover. The multiple tests performed include real-time monitoring of the water level drawdown (magnitude, duration, rate), the negative air pressures in the bedrock cavity and the cover, and several features of the subsidence phenomena (deformation style, size, magnitude, rate). The main findings derived from the test results include: (1) Vacuum pressure may trigger the development of cover collapse sinkholes in areas with low-permeability covers. (2) Different water-table decline patterns (magnitude, duration, rate) may result in different subsidence styles or rheological behaviours: sagging versus collapse. (3) Ground fissuring, frequently related to extension at the margin of sagging depressions, may cancel or significantly diminish the vacuum effect. (4) An overall direct relationship between the water-table decline rate and the subsidence rate. Some possible strategies are proposed to ameliorate the adverse effect of the negative air pressure on sinkhole hazard, which most probably has a local impact restricted by the concurrence of rapid water drawdowns and low-permeability covers