181 research outputs found

    SWOT Analysis Applied to Wheat Straw Utilization as a Biofuel in Mexico

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    Wheat is one of the main crops worldwide with a production of 733 million of tons by 2015. By 2013, the wheat grain production in Mexico was 3,357,307 t. Wheat straw is generated as a biomass waste once the wheat is harvested. However, the agricultural biomass waste has acquired international relevance as a source of bioenergy. The utilization of bioenergy has significant environmental benefits, and also economic benefits because the biomass waste is valorized as biofuel. The use of wheat straw as raw material for any productive process presents diverse factors that must be considered. Among those factors are the low density of biomass, handling and high transportation cost, an attractive heating value, and the physicochemical characterization. Therefore, the aim of this work was to apply the SWOT analysis to wheat straw utilization as a biofuel in Mexico. The main findings highlighted an estimation of 4,612,950.23 t of wheat straw generated. The experimental results of proximate analysis were 64.42% volatile matter, 19.49% fixed carbon and 16.09% ash. The higher heating was 14.86 MJ/kg. An energy potential of 69 PJ per agricultural cycle was calculated, equivalent to 19% of the biomass energy share reported in Mexico’s National Energy Balance, by 2014

    Wheat Straw Open Burning: Emissions and Impact on Climate Change

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    The state of Baja California, Mexico, is the second national wheat producer. Mexicali, the capital of Baja California, is the primary wheat producer, and it represents the most significant crop in the valley, with 90,609 ha of a cultivated surface by 2015; it leads to a wheat production of 585,334 t and a generation of 661,446 t of wheat straw as agricultural residue. The 15% of this waste has various uses. The 85% of wheat straw is open burnt in situ to prepare the farmland for the next agricultural cycle. Through the development of an emissions and energy model on iThink®, the emissions of 6,185 t of PM, 35,983 t of CO, and 1,125 t of CH4 considering a headfire burning or 3,373 t of PM, 30,360 t of CO, and 731 t of CH4 by backfire burning were estimated. Also, the wheat straw wasted energy was estimated at 8.15 PJ by 2015, with a lower heating value of 14.50 MJ/kg determined experimentally. The results highlight that for each hectare of harvested wheat, 6.205 t of wheat straw are generated and burnt. It represents the emission of pollutants and 89,972.50 MJ of wasted energy

    Essential Oil of Eucalyptus: A Natural Solution for Treating Pediculosis

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    Objective: Pediculosis is a condition caused by the infestation of Pediculus Humanus Capitis. The pesticides used in current formulations exhibit toxicity and carcinogenic effects on consumers. This study aimed to investigate the pediculicidal activity of the essential oil from Eucalyptus Globulus leaves, with the intention of adding it as an active ingredient in pediculicidal formulations to replace harmful chemicals. Design/methodology/approach: In vivo tests were conducted to assess the repellency and mortality of the essential oil obtained through hydrodistillation. The major components were determined through gas chromatography-mass spectrometry analysis. Additionally, proximate, and chemical composition analyses were performed on the eucalyptus leaves using ASTM E871, ASTM E872, ASTM D1104, TAPPI T264, TAPPI T207, ASTM D1106, and ASTM D1104 methods. Results: A repellency of 66.66% and 100% mortality within 2.26 minutes were obtained in the in vivo tests. The yield of hydrodistilled essential oil was 4 mL/kg, primarily composed of 71.04% 1,8-cineole, 18.94% 4-Ethyl-m-xylene, 2.72% γ-Terpinene, and 1.23% L-α-Pinene. Furthermore, the composition of eucalyptus leaves was determined as 61.25% moisture, 30.32% volatile matter, 6% ash, 2.40% fixed carbon, 11.22% acetone extractives, 33.03% water extractives, 31.49% lignin, 69.33% holocellulose, 62.09% cellulose, and 7.24% hemicellulose. Limitations on study/implications: The pediculicidal activity study was conducted solely on the essential oil, and further testing on the formulation of the finished product is necessary. Findings/conclusions: The pediculicidal activity study was conducted solely on the essential oil, and further testing on the formulation of the finished product is necessary

    Solar Energy for a Solvent Recovery Stage in a Biodiesel Production Process

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    Recent research and development of clean energy have become essential due to the global climate change problem, which is caused largely by fossil fuels burning. Therefore, biodiesel, a renewable and ecofriendly biofuel with less environmental impact than diesel, continues expanding worldwide. The process for biodiesel production involves a significant energy demand, specifically in the methanol recovery stage through a flash separator and a distillation column. Traditionally, the energy required for this process is supplied by fossil fuels. It represents an opportunity for the application of renewable energy. Hence, the current study presents a system of thermal energy storage modeled in TRNSYS® and supported by simulations performed in ASPEN PLUS®. The aim of this research was to supply solar energy for a methanol recovery stage in a biodiesel production process. The results highlighted that it is feasible to meet 91% of the energy demand with an array of 9 parabolic trough collectors. The array obtained from the simulation was 3 in series and 3 in parallel, with a total area of 118.8 m2. It represents an energy saving of 70 MWh per year

    México y Jalisco en la coyuntura : segundo semestre de 1998

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    Análisis de coyuntura sobre los principales sucesos del segundo semestre de 1998 en Jalisco y México. El caso del FOBAPROA, la seguridad pública, los derechos humanos, las elecciones efectuadas en el período y las estrategias de los partidos políticos en Jalisco son analizados por autores diversos. Se estudia también el caso de la industria electrónica en Guadalajara y la relación de los grupos de la sociedad civil con el gobierno.ITESO, A.C

    Impact of uterine manipulator on oncological outcome in endometrial cancer surgery

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    Background: There are limited data available to indicate whether oncological outcomes might be influenced by the uterine manipulator, which is used at the time of hysterectomy for minimally invasive surgery in patients with endometrial cancer. The current evidence derives from retrospective studies with limited sample sizes. Without substantial evidence to support its use, surgeons are required to make decisions about its use based only on their personal choice and surgical experience. Objective: To evaluate the use of the uterine manipulator on oncological outcomes after minimally invasive surgery, for apparent early-stage endometrial cancer. Study Design: We performed a retrospective multicentric study to assess the oncological safety of uterine manipulator use in patients with apparent early-stage endometrial cancer, treated with minimally invasive surgery. The type of manipulator, surgical staging, histology, lymphovascular space invasion, International Federation of Gynecology and Obstetrics stage, adjuvant treatment, recurrence, and pattern of recurrence were evaluated. The primary objective was to determine the relapse rate. The secondary objective was to determine recurrence-free survival, overall survival, and the pattern of recurrence. Results: A total of 2661 women from 15 centers were included; 1756 patients underwent hysterectomy with a uterine manipulator and 905 without it. Both groups were balanced with respect to histology, tumor grade, myometrial invasion, International Federation of Gynecology and Obstetrics stage, and adjuvant therapy. The rate of recurrence was 11.69% in the uterine manipulator group and 7.4% in the no-manipulator group (P<.001). The use of the uterine manipulator was associated with a higher risk of recurrence (hazard ratio, 2.31; 95% confidence interval, 1.27–4.20; P=.006). The use of uterine manipulator in uterus-confined endometrial cancer (International Federation of Gynecology and Obstetrics [FIGO] I–II) was associated with lower disease-free survival (hazard ratio, 1.74; 95% confidence interval, 0.57–0.97; P=.027) and higher risk of death (hazard ratio, 1.74; 95% confidence interval, 1.07–2.83; P=.026). No differences were found regarding the pattern of recurrence between both groups (chi-square statistic, 1.74; P=.63). Conclusion: In this study, the use of a uterine manipulator was associated with a worse oncological outcome in patients with uterus-confined endometrial cancer (International Federation of Gynecology and Obstetrics I–II) who underwent minimally invasive surgery. Prospective trials are essential to confirm these results

    México y Jalisco en la coyuntura : primer semestre de 1998

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    Análisis de coyuntura sobre los principales sucesos del primer semestre de 1997 en Jalisco, a nivel político, económico y social: la situación en el estado de los tres principales partidos políticos (PAN, PRI y PRD), la cuestión laboral, los derechos humanos y el problema de abastecimiento de agua en la zona metropolitana de Guadalajara.ITESO, A.C

    A consensus statement for trauma surgery capacity building in Latin America

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    Background Trauma is a significant public health problem in Latin America (LA), contributing to substantial death and disability in the region. Several LA countries have implemented trauma registries and injury surveillance systems. However, the region lacks an integrated trauma system. The consensus conference’s goal was to integrate existing LA trauma data collection efforts into a regional trauma program and encourage the use of the data to inform health policy. Methods We created a consensus group of 25 experts in trauma and emergency care with previous data collection and injury surveillance experience in the LA. region. Experts participated in a consensus conference to discuss the state of trauma data collection in LA. We utilized the Delphi method to build consensus around strategic steps for trauma data management in the region. Consensus was defined as the agreement of ≥ 70% among the expert panel. Results The consensus conference determined that action was necessary from academic bodies, scientific societies, and ministries of health to encourage a culture of collection and use of health data in trauma. The panel developed a set of recommendations for these groups to encourage the development and use of robust trauma information systems in LA. Consensus was achieved in one Delphi round. Conclusions The expert group successfully reached a consensus on recommendations to key stakeholders in trauma information systems in LA. These recommendations may be used to encourage capacity building in trauma research and trauma health policy in the region

    Evolutionary Heritage Influences Amazon Tree Ecology

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    Lineages tend to retain ecological characteristics of their ancestors through time. However, for some traits, selection during evolutionary history may have also played a role in determining trait values. To address the relative importance of these processes requires large-scale quantification of traits and evolutionary relationships among species. The Amazonian tree flora comprises a high diversity of angiosperm lineages and species with widely differing life-history characteristics, providing an excellent system to investigate the combined influences of evolutionary heritage and selection in determining trait variation. We used trait data related to the major axes of life-history variation among tropical trees (e.g. growth and mortality rates) from 577 inventory plots in closed-canopy forest, mapped onto a phylogenetic hypothesis spanning more than 300 genera including all major angiosperm clades to test for evolutionary constraints on traits. We found significant phylogenetic signal (PS) for all traits, consistent with evolutionarily related genera having more similar characteristics than expected by chance. Although there is also evidence for repeated evolution of pioneer and shade tolerant life-history strategies within independent lineages, the existence of significant PS allows clearer predictions of the links between evolutionary diversity, ecosystem function and the response of tropical forests to global change
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