Control solar en envolvente vidriada tropical para mejorar el desempeño energético-ambiental por climatización

Con el objetivo de fundamentar la estrategia de control solar como propuesta efectiva en la rehabilitación energética de un edificio de oficinas de los años 50´s, se realiza un diagnóstico del comportamiento de la demanda energética por climatización debido a su fenestración translúcida. Para el estudio se modelan los tipos de espacios más comunes (con una, dos o tres fachadas de vidrio) los cuales son objeto de simulaciones horarias que permiten pronosticar la demanda de energía anual para enfriamiento. Además, se determina el impacto ambiental que provoca este tipo de carpintería en las condiciones tropicales, de alta incidencia solar y de producción de energía de Cuba. Se utiliza Energy Plus, el motor más reconocido y avanzado de Simulación Energética de Edificios, desarrollado por el Departamento de Energía de los EEUU. Fundamentadas en los resultados se realizan y evalúan dos propuestas de diseño de control solar en las fachadas sureste y suroeste, las cuales demuestran su efectividad a partir del ahorro pronóstico anual de energía eléctrica por climatización consecuencia del recurso de sombreado. También se demuestra la influencia de la orientación en el diseño de los elementos componentes de la envolvente vertical para favorecer, con su especificidad local, la eficiencia energética, la identidad; así como la cultura energética convocada por la dirección de la nación. In order to justify the strategy of solar control like effective proposal in the energetic rehabilitation of an office building of the years 50 ´s. This paper present a diagnosis of the behavior of the cooling energetic demand due to its glazed windows. For the study are modeled the types of spaces more common of the building (with one, two or three glass facades) which are simulated each one hour to predict the annual energy demand for cooling. In addition, the environmental impact is determined that causes this window type in the tropical conditions, of high solar incidence and dependence of fuels imported for the energy generation in Cuba. It is used Energy Plus the most advanced motor in Energy Simulation of Buildings, developed by U.S. Department of Energy Building Technologies Office. Based in the results are carried out and evaluate three designs of solar control in the facades southeast and southwest, which demonstrate their effectiveness in the saving annual of electric power for cooling. The results demonstrate the influence of the orientation in the design of the vertical envelope component elements to favor, with their local specificity, the energy efficiency and the identity, as well as the energetic culture convoked by the government of the nation.

Integrated analysis of regional energetic demand and renewable energy potentials at the example of Ludwigsburg county, Germany

This work compares heating and electricity demands with local renewable energy potentials at the example of Ludwigsburg county, a mostly suburban region in South-Western Germany. Bottom-up analyses of the energetic potentials are performed within an established regional energy simulation platform and are thus based on a consistent set of geoinformatic data. This approach has two advantages compared to a top-down analysis or using multiple specialized tools: it allows assessing energetic potentials in high spatial resolution and relates it to heating and electricity demands on a single-building scale. Secondly, it is transferable to other regions due to the widespread availability of most input data. Our results show that exploiting technical potentials for bioenergy, rooftop PV, wind onshore, and hydropower can cover 68% of electricity demand 7% of heat demand in 2019, indicating that energy autonomy is difficult to achieve for densely populated regions in Europe.

ESTIMATIVA DA DEMANDA ENERGÉTICA DE UMA SEMEADORA-ADUBADORA DE PRECISÃO EM SEMEADURA DIRETA DA SOJA

ESTIMATIVA DA DEMANDA ENERGÉTICA DE UMA SEMEADORA-ADUBADORA DE PRECISÃO EM SEMEADURA DIRETA DA SOJA CRISTIANO MÁRCIO ALVES DE SOUZA1, EDUARDO LEONEL BOTTEGA2, LEIDY ZULYS LEYVA RAFULL1, SÁLVIO NAPOLEÃO SOARES ARCOVERDE1 1 Faculdade de Ciências Agrárias, Universidade Federal da Grande Dourados, Rodovia Dourados/Itahum, km 12, 79.804-970, Dourados, MS, Brasil, [email protected], [email protected], [email protected] 2Universidade Federal de Santa Maria, Campus de Cachoeira do Sul, Rodovia Taufik Germano, 3013, 96503-205, Cachoeira do Sul, RS, Brasil, [email protected] RESUMO: A otimização dos sistemas mecanizados é essencial visando a melhoria da demanda energética dos conjuntos nas operações agrícolas e, consequentemente, redução dos custos de produção. O objetivo do trabalho foi avaliar a demanda energética de um conjunto trator-semeadora-adubadora, em função de diferentes mecanismos sulcadores e teores de água no solo sob sistema de semeadura direta da soja. O experimento foi montado em esquema de parcelas subsubdivididas, em que as parcelas constituíram os teores de água no solo (0,258; 0,277 e 0,290 g g-1), as subparcelas o tipo de sulcador (haste e disco-duplo) e as subsubparcelas os níveis de cargas aplicadas (451, 685 e 893 N) na linha da semeadora-adubadora, no delineamento em blocos casualizados, com três repetições. O teor de água no solo influencia diferentemente a demanda energética do conjunto trator-semeadora-adubadora em função do tipo de sulcador. O uso da haste sulcadora aumenta a patinagem, a potência e força específicas de tração, sendo a força maior para a haste independentemente da profundidade de corte do solo. Houve aumento da força e potência específicas de tração com o aumento da profundidade de corte do solo para ambos os sulcadores, bem como do consumo específico de combustível quando utilizada a haste sulcadora. Palavras-chaves: haste sulcadora, patinagem, umidade do solo, potência. ESTIMATION OF PRECISION SEEDER-FERTILIZER ENERGETIC DEMAND IN SOYBEAN NO-TILL ABSTRACT: The optimization of mechanized systems is essential to improve the energy demand of the sets in agricultural operations and, consequently, reduce production costs. The work's objective was to evaluate a tractor-seeder-fertilizer system's energy demand due to different furrow openers and soil moisture under soybean's no-till. The experimental delineation adopted was the complete random blocks in a split-split-plot scheme in which the plots consisted of three soil moisture (0.258, 0.277 and 0.290 g g-1), the subplots of two mechanisms for furrow opening (hoe opener and double disk), and the sub-subplots of three applied loads (451, 685 and 893 N) in the seeder row on the soil, with three replications. The soil moisture influences the energy demand of the tractor-seeder-fertilizer system differently due to the furrow opener type. The hoe opener's use increases the wheel slippage, power demand, being the power greater for hoe opener regardless of the cutting depth. There was an increase in power demand with the rise of the cutting depth for both furrow openers, while the greater specific fuel consumption was using the hoe opener. Keywords: furrow opener, wheel slippage, soil moisture, power.

Interspecies differences in proteome turnover kinetics are correlated with lifespans and energetic demands

Cells continually degrade and replace damaged proteins. However, the high energetic demand of protein turnover generates reactive oxygen species (ROS) that compromise the long-term health of the proteome. Thus, the relationship between aging, protein turnover and energetic demand remains unclear. Here, we used a proteomic approach to measure rates of protein turnover within primary fibroblasts isolated from a number of species with diverse lifespans including the longest-lived mammal, the bowhead whale. We show that organismal lifespan is negatively correlated with turnover rates of highly abundant proteins. In comparison to mice, cells from long-lived naked mole rats have slower rates of protein turnover, lower levels of ATP production and reduced ROS levels. Despite having slower rates of protein turnover, naked mole rat cells tolerate protein misfolding stress more effectively than mouse cells. We suggest that in lieu of rapid constitutive turnover, long-lived species may have evolved more energetically efficient mechanisms for selective detection and clearance of damaged proteins.

Why is C4 photosynthesis so rare in trees?

Since C4 photosynthesis was first discovered >50 years ago, researchers have sought to understand how this complex trait evolved from the ancestral C3 photosynthetic machinery on >60 occasions. Despite its repeated emergence across the plant kingdom, C4 photosynthesis is notably rare in trees, with true C4 trees only existing in Euphorbia. Here we consider aspects of the C4 trait that could limit but not preclude the evolution of a C4 tree, including reduced quantum yield, increased energetic demand, reduced adaptive plasticity, evolutionary constraints, and a new theory that the passive symplastic phloem loading mechanism observed in trees, combined with difficulties in maintaining sugar and water transport over a long pathlength, could make C4 photosynthesis largely incompatible with the tree lifeform. We conclude that the transition to a tree habit within C4 lineages as well as the emergence of C4 photosynthesis within pre-existing trees would both face a series of challenges that together explain the global rarity of C4 photosynthesis in trees. The C4 trees in Euphorbia are therefore exceptional in how they have circumvented every potential barrier to the rare C4 tree lifeform.

Interspecies differences in proteome turnover kinetics are correlated with lifespans and energetic demands

Cells continually degrade and replace damaged and old proteins. However, the high energetic demand of protein turnover generates reactive oxygen species (ROS) that compromise the long-term health of the proteome. Thus, the relationship between aging, protein turnover and energetic demand remains unclear. Here, we used a proteomic approach to measure rates of protein turnover within primary fibroblasts isolated from a number of species with diverse lifespans including the longest-lives rodent, the naked mole rat and the longest-lived mammal, the bowhead whale. We show that organismal lifespan is negatively correlated with turnover rates of highly abundant proteins. In comparison to mice, cells from long-lived naked mole rats have slower rates of protein turnover, lower levels of ATP production and reduced ROS levels. Despite having slower rates of protein turnover, naked mole rat cells tolerate protein misfolding stress more effectively than mouse cells. We suggest that in lieu of rapid constitutive turnover, long-lived species may have evolved more energetically efficient mechanisms for selective detection and clearance of damaged proteins.

Black soldier fly (Hermetia illucens L.): effect on the fat integrity using different approaches to the killing of the prepupae

The increase of waste, due to the rise of the world population, renders the use of the black soldier fly (BSF; Hermetia illucens) as agri-food leftover biotransformer very attractive. Indeed, feeding on these substrates, BSF is capable of transforming them into valuable fat, proteins, and chitin. The present study is aimed at evaluating different approaches to the killing of the prepupae in order to assess which is associated with the lowest production of artefacts, notably free fatty acids. Folch extraction method, via an Ultra-Turrax homogeniser, was selected to isolate and analyse prepupal fat. The same method was also applied for a direct grinding method to kill black soldier fly prepupae. The integrity of fat originated from this direct grinding approach to the killing was compared in terms of fatty acid profile with the samples obtained with two other killing procedures, i.e. freezing and blanching. Direct grinding proved to be a better preservative of fat integrity in terms of lowest amount of free fatty acids (about 2.5%) in comparison with freezing (about 15%), but also with blanching (about 10%). Furthermore, the direct grinding is a killing strategy that reduces energetic demand and process time and helps lower analytical costs.

Circadian Regulation of Cardiac Physiology: Rhythms That Keep the Heart Beating

On Earth, all life is exposed to dramatic changes in the environment over the course of the day; consequently, organisms have evolved strategies to both adapt to and anticipate these 24-h oscillations. As a result, time of day is a major regulator of mammalian physiology and processes, including transcription, signaling, metabolism, and muscle contraction, all of which oscillate over the course of the day. In particular, the heart is subject to wide fluctuations in energetic demand throughout the day as a result of waking, physical activity, and food intake patterns. Daily rhythms in cardiovascular function ensure that increased delivery of oxygen, nutrients, and endocrine factors to organs during the active period and the removal of metabolic by-products are in balance. Failure to maintain these physiologic rhythms invariably has pathologic consequences. This review highlights rhythms that underpin cardiac physiology. More specifically, we summarize the key aspects of cardiac physiology that oscillate over the course of the day and discuss potential mechanisms that regulate these 24-h rhythms.

Loss of Gpr68 Enhances Hematopoietic Stem Cell Function during Aging

Recent studies implicate metabolic plasticity in fine-tuning hematopoietic stem cell (HSC) homeostasis and function. HSC have been shown to rely on anaerobic glycolysis due to low energetic demand. In contrast, mitochondrial respiration is largely engaged to meet high energetic demand under certain pathophysiological processes, such as differentiation, aging and malignant transformation. The microenvironment, i.e. the HSC niche, has long been known as hypoxic. Glycolytic pathway is not only the metabolic adaptation to the hypoxic niche, but also essential for HSC function at least by providing prosurvival signals. However, glycolysis is reduced in HSC upon aging, which is associated with diminished regeneration ability of HSC. How glycolysis impacts HSC biology is unclear. G protein-coupled receptor 68 (GPR68, also known as OGR1) responds to extracellular acidosis, activating the phospholipase C (PLCb)/calcium pathway or the adenylyl cyclase (CA)/cAMP pathway. The end point product of glycolysis is lactate that leads to extracellular acidosis. This prompts us to examine the role of Gpr68 in HSC biology. Among the hematopoietic stem and progenitor cell (HSPC) subpopulations, we found that Gpr68 expression was most enriched in mouse long-term HSC (LT-HSC, Lin-Sca-1+c-Kit+CD34-CD135-). To understand the function of Gpr68 in HSC biology, we generated a genetic loss of function mouse model (i.e. the Gpr68fl/fl;VavCre+ mice) where Gpr68 was specifically deleted in hematopoietic cells, including the most primitive LT-HSC. We found that the number of LT-HSC was unaltered in bone marrow (BM) from Gpr68fl/fl;VavCre+ mice as compared to wild type (WT) control littermates (i.e. the Gpr68wt/wt;VavCre+ mice), indicating that Gpr68 was not required for HSC homeostasis. To examine the role of Gpr68 in HSC function, we performed competitive bone marrow transplantation (cBMT). The donor-derived chimerism (i.e. the frequency of CD45.2+ cells) was increased in recipients with BM cells from Gpr68fl/fl;VavCre+ mice (12-month old) compared to those from age-matched WT mice after primary cBMT, which was increased even more dramatically after secondary cBMT. This indicates enhanced HSC regeneration ability due to loss of Gpr68. Increased chimerism was observed in CD3+ T lymphocytes, B220+ B lymphocytes and CD11b+ myeloid cells, indicating that both lymphoid and myeloid lineages contributed to enhanced HSC function. Consistently, increased chimerism was also observed in BM HSPC subpopulations except the LT-HSC. Of note, increased chimerism was not observed in recipients that were transplanted with BM cells from young Gpr68fl/fl;VavCre+ mice (2-month old). In addition, BM cells from Gpr68fl/fl;VavCre+ mice produced slightly reduced colonies in methylcellulose, indicating that loss of Gpr68 did not lead to malignant transformation despite enhanced competitiveness of HSC. To further understand the mechanism of Gpr68 in regulating HSC function, we studied cellular features of HSPC subpopulations. The frequency of cells in cell cycle G0 phase was unchanged in LT-HSC from Gpr68fl/fl;VavCre+ mice as compared to WT mice, indicating loss of quiescence may not contribute to enhanced HSC function. Intriguingly, the frequency of Annexin V+ cells was largely reduced in LT-HSC from Gpr68fl/fl;VavCre+ mice as compared to WT mice, suggesting that loss of Gpr68 provides a pro-survival signal in HSC. We next examined two main signaling pathways downstream of Gpr68. Cytosolic calcium levels were reduced in LT-HSC from Gpr68fl/fl;VavCre+ mice as compared to WT mice, indicating Gpr68 may activate a calcium-related proapoptotic pathway. In contrast, intracellular cAMP levels were increased in HSPC, possibly from unknown compensatory mechanism. In addition, Gpr68 expression was reduced in LT-HSC from older mice (12-month old) compared to younger mice (2-month old), indicating reduced Gpr68 function at 12-month of age. This is in line with reduced glycolysis in aged HSC. Our study suggests that Gpr68 mediates a proapoptotic pathway in LT-HSC, providing a negative regulation, possibly at downstream of glycolysis, that limits HSC function. Our study also suggests that inhibiting Gpr68 function would enhance HSC function, especially in aged people or during bone marrow transplantation. Disclosures No relevant conflicts of interest to declare.