37 research outputs found

    La Historia Socioambiental del Agua Desde el Metabolismo Social para la Implementación de Un Sistema de Desalinización Solar en Samalayuca, Chihuahua, México (2000-2020)

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    Analyzing the social metabolism over time helps to understand the socio-environmental transformations of the territory and society from tangible and intangible aspects related to socio-cultural factors of water. The present study relates the transformations through time through the social metabolism of a town in semi-arid conditions in the north of Mexico (Samalayuca, Chihuahua), in order to know the socio-environmental aspects that can influence the appropriation of a Solar Desalination (SDS) in a family with well water with high salinity, as well as the sociocultural changes of the family after a year of use of the System. For which, a content analysis of hemerographic notes of the town was carried out, from 2000 to 2020, and a follow-up through interviews with users. The socio-environmental aspects identified have as a constant that they are triggered by the perception of a risk in the availability or quality of water, especially if their main economic activity, which is agriculture, is affected. The conflict with a greater approach is the authorization of a mine to Open-pit copper extraction, in which mobilizations were held that achieved protection and the cancellation of the start of activities. They highlight non-violent social action and solidarity when they have faced lack of water. Regarding the SDS, it was installed in October 2019, managing to cover the needs of the family, related to their subsistence, a commitment to the care of the System and an appreciation for water was observed. It highlights the importance of considering both the socio-environmental aspects of a population, as well as the intangible aspects at the time an Appropriation is desired, such as a technological intervention for access to quality water in semi-arid regions.A Analizar el metabolismo social a través del tiempo contribuye a entender las transformaciones socioambientales del territorio y la sociedad desde aspectos tangibles e intangibles relacionados con factores socioculturales del agua. El presente estudio, relaciona las transformaciones a través del tiempo por medio del metabolismo social de un poblado en condiciones semiáridas al norte de México (Samalayuca, Chihuahua), con el fin de conocer los aspectos socioambientales que pueden influir en la apropiación de un Sistema de Desalinización Solar (SDS) en una familia con agua de pozo con alta salinidad, así como los cambios socioculturales de la familia después de un año de uso del Sistema. Para lo cual, se realizó un análisis de contenido de notas hemerográficas del poblado, del 2000 al 2020, y un seguimiento por medio de entrevistas a los usuarios. Los aspectos socioambientales identificados tienen como constante que los detonan la percepción de un riesgo en la disponibilidad o calidad del agua, sobre todo si ven afectada su principal actividad económica que es la agricultura, el conflicto con un mayor abordaje es la autorización de una mina para extracción de Cobre a cielo abierto, en la cual se tuvieron movilizaciones que lograron el amparo y la cancelación del inicio de actividades. Destacan la acción social no violenta y la solidaridad cuando han enfrentado carencia de agua. Sobre el SDS, se instaló en octubre de 2019, logrando cubrir las necesidades de uso de la familia, relacionadas con su subsistencia, se observó un compromiso por el cuidado del Sistema y un aprecio por el agua. Destaca la importancia de considerar tanto los aspectos socioambientales de una población, como los aspectos intangibles en el momento que se desea llevar a cabo una Apropiación, como lo es una intervención tecnológica para acceso a un agua de calidad en regiones semiáridas.Analizar el metabolismo social a través del tiempo contribuye a entender las transformaciones socioambientales del territorio y la sociedad desde aspectos tangibles e intangibles relacionados con factores socioculturales del agua. El presente estudio, relaciona las transformaciones a través del tiempo por medio del metabolismo social de un poblado en condiciones semiáridas al norte de México (Samalayuca, Chihuahua), con el fin de conocer los aspectos socioambientales que pueden influir en la apropiación de un Sistema de Desalinización Solar (SDS) en una familia con agua de pozo con alta salinidad, así como los cambios socioculturales de la familia después de un año de uso del Sistema. Para lo cual, se realizó un análisis de contenido de notas hemerográficas del poblado, del 2000 al 2020, y un seguimiento por medio de entrevistas a los usuarios. Los aspectos socioambientales identificados tienen como constante que los detonan la percepción de un riesgo en la disponibilidad o calidad del agua, sobre todo si ven afectada su principal actividad económica que es la agricultura, el conflicto con un mayor abordaje es la autorización de una mina para extracción de Cobre a cielo abierto, en la cual se tuvieron movilizaciones que lograron el amparo y la cancelación del inicio de actividades. Destacan la acción social no violenta y la solidaridad cuando han enfrentado carencia de agua. Sobre el SDS, se instaló en octubre de 2019, logrando cubrir las necesidades de uso de la familia, relacionadas con su subsistencia, se observó un compromiso por el cuidado del Sistema y un aprecio por el agua. Destaca la importancia de considerar tanto los aspectos socioambientales de una población, como los aspectos intangibles en el momento que se desea llevar a cabo una Apropiación, como lo es una intervención tecnológica para acceso a un agua de calidad en regiones semiáridas

    Environmental Impact Assessment for an Absorption Heat Transformer

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    Abstract This study presents the environmental impact assessment of an absorption heat transformer designed to recover 1 kW of thermal energy from each 2 kW of waste heat supplies. The net contribution of the heat transformer is a load avoided of 0.665 kg CO2 equivalents; the recovery process avoids 0.729 kg CO2 equivalents and the major contribution to the environment impacts is the pumping process with 0.0437 kg CO2 equivalents for each 1 kWh recovered. The study results show that absorption heat transformer is a good environmental option because it produces useful energy from waste heat and the final result is an environmental impact diminution

    Design and Construction for Hydroxides Based Air Conditioning System with Solar Collectors for Confined Roofs

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    In this chapter, the methodology to determinate heat load is revised and presented. The main parameters must be fixed as function of climatization, internal thermic conditions (comfort, temperature, and humid) and the activities. According with literature, the roof structural requirements were checked. These are an important parameter because it represents the limits to the system such as load by devices (weight of equipment), orientation in solar systems (operating conditions), and building materials. The method of calculation of solar available is shown; the aim is to achieve the major collection of solar energy. Finally, the plate heat exchangers can be fabricated in gasketed, welded or module welded design characterized by the model in which the flow channels for the two heat exchanging media are sealed. The kind of exchanger is suitable depending on your requirements. The thermodynamic method of calculation of sizing the exchangers is reviewed. The aim of this section is to find the suitable devices for the operation of air-conditioning absorption system based on hydroxide

    Impact of metabolic syndrome on the risk of endometrial cancer and the role of lifestyle in prevention

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    Endometrial cancer is the second gynecological cancer with the highest global incidence. Among many associated risk factors, metabolic syndrome is an important and preventable one. It comprises a group of conditions that often occur together: central adiposity, hyperglycemia, arterial hypertension, and atherogenic dyslipidemia. This review aimed to describe the epidemiological and biological relationship between metabolic syndrome and endometrial cancer, focusing on the role of lifestyle in prevention. A literature search was carried out in the PubMed database. 4824 publications were screened, and 123 were included for this review. The association between metabolic syndrome and endometrial cancer has been described. Chronic adipose tissue inflammation and insulin resistance are involved in the development of obesity, particularly visceral adiposity. These changes promote the ideal environment for the development of endometrial cancer. Strategies based on lifestyle modifications may be effective for the prevention of metabolic syndrome and consequently endometrial cancer. Some of these modifications include adopting a diet rich in fruits, vegetables, whole grains, and legumes, depending to the accessibility of these foods for each region. Avoiding ultra-processed foods and increasing daily physical activity were also some suggested modifications. We propose that women be screened for metabolic syndrome to establish early treatment and to possibly prevent endometrial cancer. Clinical trials designed to prove the effect of lifestyle modifications on the prevention of endometrial cancer are needed

    Osteogenic potential of murine periosteum for critical-size cranial defects.

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    Tissue engineering of bone has combined bespoke scaffolds and osteoinductive factors to maintain functional osteoprogenitor cells, and the periosteum has been confirmed as a satisfactory source of osteoblasts. Suitable matrices have been identified that support cell proliferation and differentiation, including demineralised bone matrix (both compatible and osteoinductive) and acellular human dermis. We have evaluated the osteogenic potential of an osteogenic unit, developed by combining periosteum, demineralised bone matrix, and acellular human dermis, in rodents with critical-size cranial defects. Briefly, remnants from the superior maxillary periosteum were used to harvest cells, which were characterised by flow cytometry and reverse retrotranscriptase-polymerase chain reaction (RT-PCR). Cells were cultured into the osteogenic unit and assessed for viability before being implanted into 3 rodents, These were compared with the control group (n=3) after three months. Histological analyses were made after staining with haematoxylin and eosin and Von Kossa, and immunostaining, and confirmed viable cells that stained for CD90, CD73, CD166, runt-related transcription factor, osteopontin, and collagen type I in the experimental group, while in the control group there was only connective tissue on the edges of the bone in the injury zone. We conclude that osteogenic unit constructs have the osteogenic and regenerative potential for use in engineering bone tissue

    Role of Membrane Technology in Absorption Heat Pumps: A Comprehensive Review

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    The role of heat pumps is linked to the actions of human life. Even though the existing technologies perform well in general, they have still some problems, such as cost, installation area, components size, number of components, noise, etc. To address these issues, membrane technologies have been introduced in both heat and cooling devices. The present work proposes and studied the review of the role of membrane technology in the heat pumps. The study focuses on the advancement and replacement of membrane in the place of absorption and compression heat pump components. The detailed analysis and improvements are focused on the absorber, desorber, and heat and mass exchanger. The parameters conditions and operation of membrane technologies are given in detail. In addition to this, the innovation in the heat pumps using the membrane technology is given in detail

    Experimental Performance of a Membrane Desorber with a H2O/LiCl Mixture for Absorption Chiller Applications

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    For absorption cooling cycles using water as a refrigerant, H2O/LiCl mixtures are suitable for replacing conventional H2O/LiBr mixtures. In addition, membrane devices can be used to develop compact and lighter absorption systems, and they can operate with H2O/LiCl mixtures. The present paper describes an experimental evaluation of a membrane desorber/condenser operating at atmospheric pressure. Two operation modes were analyzed: continuous cycle operation and intermittent operation. For the first operation mode, the maximum desorption rate was 3.49 kg/h·m2, with a solution temperature of 90.3 °C and a condensation temperature of 25.1 °C. The lowest desorption rate value was 0.26 kg/h·m2, with a solution temperature of 75.4 °C and a condensation temperature of 40.1 °C. In the second mode, after three operating hours, the refrigerant fluid produced, per 1 m2 of membrane area, 7.7, 5.6, 4.3, and 2.2 kg, at solution temperatures of 90.3, 85.3, 80.4, and 75.4 °C, respectively. A one-dimension heat and mass transfer model is presented. The calculated values of desorption rate and outlet temperatures were compared with the experimental data; a square correlation coefficient of 0.9929 was reached for the desorption rate; meanwhile, for the outlet solution temperatures and the outlet cooling-water temperatures, a square correlation coefficient up to 0.9991 was achieved. The membrane desorber has the advantages of operating at atmospheric-pressure conditions, high condensation temperature, the ability to use different saline solution working mixtures, and different operation methods. These advantages can lead to new absorption systems

    Parametric Methodology to Optimize the Sizing of Solar Collector Fields in Series-Parallel Arrays

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    The analysis of solar thermal systems through numerical simulation is of great importance, since it allows predicting the performance of many configurations in any location and under different climatic conditions. Most of the simulation tools are commercial and require different degrees of training; therefore, it is important to develop simple and reliable methodologies to obtain similar results. This study presents a parametric methodology to size stationary solar collector fields, with operating temperatures up to 150 °C. The costs of the collector loop piping and the pumping power of different series−parallel arrays is considered. The proposed tool was validated with experimental data and through simulations using commercial software. The tool allows establishing series−parallel arrays and calculates the volume of the storage tank according to the thermal load. The calculation is based on the system energy balance, where the mass flow and the heat losses in the interconnections of the collectors are taken into account. The number of collectors and the optimal series−parallel array were determined. The results show deviations lower than 7% in the relative error of the temperature profiles and in the solar fraction, with respect to the results obtained by dynamic simulations

    Review of solar-thermal collectors powered autoclave for the sterilization of medical equipment

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    This literature review was based on articles published on different types of solar autoclaves used to sterilize the medical instruments. The present paper analysis the various types of solar thermal technologies and the materials used for manufacture. The operating conditions (temperature and pressure) of steam sterilizer used, the climatic conditions as well as the health center where the prototype was tested and installed were also investigated. It emerged from the revised articles that steam sterilizers are part of the systems in which solar thermal energy was used since the 1970s. Conventional solar thermal technologies were the first to be used in solar autoclave prototypes. Due to the high cost of these collectors, several researchers have invested in the design of new prototypes both solar collectors and sterilizers, based on less expensive materials. It has also observed that solar autoclave can hold a pressure steam of 0.10 MPa keeping the internal temperature at 121–140 °C for about 15–20 min
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