A meta-study of the effect of thermodynamic parameters on the efficiency of geothermal power plants worldwide

As global energy demand rises, the search for viable alternative fuel sources continues. The practicality of geothermal energy to meet this demand is highly dependent on optimizing thermal efficiency. While geothermal energy is currently used in places like Western Australia for direct-heat applications such as leisure centres, developing a geothermal power plant in such an area depends on predicting which thermodynamic parameters optimize thermal efficiency. This meta-study focuses on the effect of geothermal operation parameters such as inlet pressure, temperature, mass flow rate, well depth and number of production wells on the thermal efficiency of geothermal power plants. Drawing data from 61 geothermal power plants around the world ranging in design capacity (MWe) and size, a meta-study on the thermal efficiency of plants operating under different thermodynamic cycles, namely single-flash, double-flash, binary Organic Rankine Cycle (ORC) and Kalina, is offered. These various thermodynamic parameters are analysed to determine the presence of observable thermal efficiency patterns or trends that may lead to the optimization of operation parameters for new geothermal plants. Based on the available published data reviewed, there are few trends which indicate how geothermal operation parameters affect thermal efficiency. Well depth may be an indicator of efficiency for geothermal power plants using ORC and double-flash cycles, however further data is required to support this conclusion

Aplicación de un módulo educativo utilizando sensores atmosféricos para el aprendizaje del medio ambiente en la I.E Javier Pérez de Cuellar S.J.L 2018

La presente investigación busco Evaluar la influencia de la aplicación de un módulo educativo utilizando sensores atmosféricos en el aprendizaje del medio ambiente en la I.E Javier Pérez de Cuellar. S.J.L, el método de la investigación fue experimental de enfoque cuantitativo, tipo aplicada cuyo diseño fue cuasi experimental. La población fue conformada por 52 estudiantes de la institución educativa #126 Javier Pérez de Cuellar, “S.J.L”, durante el periodo 2018, la muestra fue no probabilística de manera intencional debido que los mismos alumnos faltaban a clase, con dos grupos d estudiantes del mismo grado constituida por 40 estudiantes (20 para el grupo experimental y 20 para el grupo de control). Se empleó técnica de recolección de datos, como la técnica de evaluación educativa se utilizó tres instrumentos aplicados en dos momentos, lista de cotejo (Pre test y post test), el cuestionario (Pre test y post test) y aplicación del módulo educativa utilizando sensores atmosféricos) Con un nivel de confiabilidad realizado mediante el coeficiente de kuder 20, cuyo valor fue 0.78 El resultado de la investigación se hizo con U de Mann Whitney con un nivel de confianza de 95% nos permitió concluir que: la aplicación módulo educativo influyo significativamente en el aprendizaje del medio ambiente utilizando sensores atmosféricos en la I.E Javier Pérez de Cuellar. S.J.L 2018 respecto a los alumnos que no utilizaron el módulo educativo con un p< 0.005) significancia observada p= 0.00 menor que la significancia teóric

Dificultades docentes en el refuerzo de forjados de madera mediante la conexión de una losa de hormigón superior

En este trabajo se analizan desde el punto de vista docente el conjunto de operaciones necesarias para dimensionar refuerzos de forjados de madera mediante recrecidos de hormigón. La técnica posee un marcado carácter pluridisciplinar y todos los conocimientos necesarios para su implementación no se desarrollan a lo largo de los planes de estudio de la mayoría de las titulaciones técnicas. Sin embargo, tal como se pone de manifiesto con el desarrollo de un caso, con unos conocimientos conceptuales de rehabilitación de estructuras y el manejo de algunas herramientas de cálculo de estructuras, pueden abordarse con éxito estas operaciones

A Comprehensive Study on the Occurrence of Mycotoxins and Their Producing Fungi during the Maize Production Cycle in Spain

Mycotoxin contamination is one of the main problems affecting corn production, due to its significant risk to human and animal health. The Fusarium and Aspergillus species are the main producers of mycotoxins in maize, infecting both pre-harvest and during storage. In this work, we evaluated the presence of mycotoxins and their producing species along maize production cycles in three different stages (anthesis, harvest, and storage) during three consecutive seasons (2016–2018). Fungal occurrences were studied using species-specific PCR protocols, whereas mycotoxin levels were determined by LC-MS/MS. Fumonisin-producing Fusarium species (F. verticillioides and F. proliferatum), as well as the aflatoxin producer Aspergillus flavus, were the most predominant species at all stages; although, during some seasons, the presence of F. graminearum and A. niger aggregate species were also identified. Contrastingly, fumonisins were the only mycotoxins detected and levels were always under legal regulations. The results presented here demonstrate that even when fungal contamination occurs at the early stages of the maize production cycle, the application of good agricultural and storage practices might be crucial to ensure mycotoxin-free grains

Efficacy of atmospheric pressure dielectric barrier discharge for inactivating airborne pathogens

Atmospheric pressure plasmas have gained attention in recent years for several environmental applications. This technology could potentially be used to deactivate airborne microorganisms, surface-bound microorganisms, and biofilms. In this work, the authors explore the efficacy of the atmospheric pressure dielectric barrier discharge (DBD) to inactivate airborne Staphylococcus epidermidis and Aspergillus niger that are opportunistic pathogens associated with nosocomial infections. This technology uses air as the source of gas and does not require any process gas such as helium, argon, nitrogen, or hydrogen. The effect of DBD was studied on aerosolized S. epidermidis and aerosolized A. niger spores via scanning electron microscopy (SEM). The morphology observed on the SEM micrographs showed deformations in the cellular structure of both microor- ganisms. Cell structure damage upon interaction with the DBD suggests leakage of vital cellular materials, which is a key mechanism for microbial inactivation. The chemical structure of the cell surface of S. epidermidis was also analyzed by near edge x-ray absorption fine structure spectros- copy before and after DBD exposure. Results from surface analysis revealed that reactive oxygen species from the DBD discharge contributed to alterations on the chemistry of the cell membrane/ cell wall of S. epidermidis

Aislamiento bacteriológico y caracterización de lesiones histopatológicas en tetra bleeding heart (Hyphessobrycon erythrostigma) de la cuenca Amazónica Peruana

The aim of this study was to determine the presence of bacterial agents and to characterize the histopathological lesions in ornamental tetra bleeding heart (Hyphessobrycon erytrhostigma) fish from a commercial aquarium in the city of Iquitos, Peru. For the microbiological study 60 fish were used, samples were taken from spleen and kidney. Isolation was done on MacConkey agar, Trypticase Soy agar, Pseudomonas Aeromonas selective agar (GSP) and Cytophaga agar and the genus identification was done by Gram staining and biochemical tests. Another 60 fish were used for the histopathological study where the skin, eye, gills, stomach, intestine, liver, spleen, muscle, kidney and peritoneum tissues were analyzed. Seven bacterial genera were isolated: Pseudomonas, Aeromonas, Lactobacillus, Bacillus, Flavobacterium, Staphylocccus and Escherichia. Spores of Mixosporidium sp, hyperplasia and lamella fusion were observed in gills. In the liver and peritoneum, parasitic and bacterial granulomas were found. In muscle, kidney and spleen, bacterial granulomas were found, and in stomach and intestine epithelial cell hyperplasia were found, among other lesions. Results showed that 52.3% (22/42) of the bacterial granulomas were positive for Ziehl Neelsen staining, which showed acid-fast bacilli bacteria. No lesions were found in the eyes.El objetivo del presente estudio fue determinar la presencia de agentes bacterianos y caracterizar las lesiones histopatológicas en tejidos del pez ornamental ‘tetra bleeding heart’ (Hyphessobrycon erytrhostigma) procedentes de un acuario comercial de la ciudad de Iquitos, Perú. Para el estudio microbiológico se utilizaron 60 peces, tomándose muestras de bazo y riñón. El aislamiento se hizo en agar MacConkey, agar Tripticasa de Soya, agar selectivo para Pseudomonas-Aeromonas (GSP) y agar Cytophaga. La identificación de los géneros bacterianos se hizo mediante la coloración Gram y pruebas bioquímicas. Para el estudio histopatológico se utilizaron otros 60 peces, evaluándose los tejidos de piel, ojo, branquias, estómago, intestino, hígado, bazo, músculo, riñón y peritoneo. Se aislaron siete géneros bacterianos: Pseudomonas, Aeromonas, Lactobacillus, Bacillus, Flavobacterium, Staphylocccus y Escherichia. En los estudios histopatológicos, se observó en las branquias la presencia de esporas de Mixosporidium sp, hiperplasia y fusión de lamelas; en hígado y peritoneo se hallaron granulomas parasitarios y bacterianos; en músculo, riñón y bazo se encontraron granulomas bacterianos; y en el estómago e intestino se observó hiperplasia de las células epiteliales, entre otras lesiones. El 52.3% (22/42) de los granulomas bacterianos fueron positivos a la tinción de Ziehl Neelsen, donde se evidenció bacterias bacilares largas acidorresistentes. No se observaron lesiones en los ojos

Comparison of direct and indirect models of early induced acute lung injury

The animal experimental counterpart of human acute respiratory distress syndrome (ARDS) is acute lung injury (ALI). Most models of ALI involve reproducing the clinical risk factors associated with human ARDS, such as sepsis or acid aspiration; however, none of these models fully replicates human ARDS. To compare different experimental animal models of ALI, based on direct or indirect mechanisms of lung injury, to characterize a model which more closely could reproduce the acute phase of human ARDS. Adult male Sprague-Dawley rats were subjected to intratracheal instillations of (1) HCl to mimic aspiration of gastric contents; (2) lipopolysaccharide (LPS) to mimic bacterial infection; (3) HCl followed by LPS to mimic aspiration of gastric contents with bacterial superinfection; or (4) cecal ligation and puncture (CLP) to induce peritonitis and mimic sepsis. Rats were sacrificed 24 h after instillations or 24 h after CLP. At 24 h, rats instilled with LPS or HCl-LPS had increased lung permeability, alveolar neutrophilic recruitment and inflammatory markers (GRO/KC, TNF-α, MCP-1, IL-1β, IL-6). Rats receiving only HCl or subjected to CLP had no evidence of lung injury. Rat models of ALI induced directly by LPS or HCl-LPS more closely reproduced the acute phase of human ARDS than the CLP model of indirectly induced ALI

Nebulized Heparin Attenuates Pulmonary Coagulopathy and Inflammation through Alveolar Macrophages in a Rat Model of Acute Lung Injury

Objective Alveolar macrophages play a key role in the development and resolution of acute respiratory distress syndrome (ARDS), modulating the inflammatory response and the coagulation cascade in lungs. Anti-coagulants may be helpful in the treatment of ARDS. This study investigated the effects of nebulized heparin on the role of alveolar macrophages in limiting lung coagulation and inflammatory response in an animal model of acute lung injury (ALI). Methods Rats were randomized to four experimental groups. In three groups, ALI was induced by intratracheal instillation of lipopolysaccharide (LPS) and heparin was nebulized at constant oxygen flow: the LPS/Hep group received nebulized heparin 4 and 8 hours after injury; the Hep/LPS/Hep group received nebulized heparin 30 minutes before and 4 and 8 hours after LPS-induced injury; the LPS/Sal group received nebulized saline 4 and 8 hours after injury. The control group received only saline. Animals were exsanguinated 24 hours after LPS instillation. Lung tissue, bronchoalveolar lavage fluid (BALF) and alveolar macrophages isolated from BALF were analysed. Results LPS increased protein concentration, oedema and neutrophils in BALF as well as procoagulant and proinflammatory mediators in lung tissue and alveolar macrophages. In lung tissue, nebulized heparin attenuated ALI through decreasing procoagulant (tissue factor, thrombin-anti-thrombin complexes, fibrin degradation products) and proinflammatory (interleukin 6, tumour necrosis factor alpha) pathways. In alveolar macrophages, nebulized heparin reduced expression of procoagulant genes and the effectors of transforming growth factor beta (Smad 2, Smad 3) and nuclear factor kappa B (p-selectin, CCL-2). Pre-treatment resulted in more pronounced attenuation. Conclusion Nebulized heparin reduced pulmonary coagulopathy and inflammation without producing systemic bleeding, partly by modulating alveolar macrophages

PVLSI (Pioneer Valley Life Sciences Institute) Posters - 2019

PVLSI (Pioneer Valley Life Sciences Institute) Posters - 2019https://scholarlycommons.libraryinfo.bhs.org/research_education/1014/thumbnail.jp