Analysis of Thin Wall Structures for Energy Absorption Applications by ABAQUS

Crash-dynamics research has always concentrated significantly in the safety, survivability of passengers in a car crash. To identify the capability of energy absorption of a crash box, a thin-walled structure will be modeled and simulated by ABAQUS software. Investigate the influence of material, cross-sectional, thickness factors on the energy absorption capacity of the tube, using MCDM – Multi-Criteria Decision-Making to get the best option and testing the improvement while filling the tube with Foam material. In this study, beside the cross-sectional, aluminum alloys and steel materials and thickness are factors that influence the energy absorption evaluation criteria, the foam material with difference density are surveyed to compare effectiveness between the foam-filled and hollow crashboxes. The results show that the folds of the foam-filled tube after deformation along the compressive direction will be more continuous and stable. More, the higher foam density, the greater the energy absorption. This prevents the crashbox from deviating from the direction of the force, help directing the collapse of the tube, thereby improving energy absorption without significantly increasing the weight of the structure.

Insights into cell wall disintegration of Chlorella vulgaris

With their ability of CO2 fixation using sunlight as an energy source, algae and especially microalgae are moving into the focus for the production of proteins and other valuable compounds. However, the valorization of algal biomass depends on the effective disruption of the recalcitrant microalgal cell wall. Especially cell walls of Chlorella species proved to be very robust. The wall structures that are responsible for this robustness have been studied less so far. Here, we evaluate different common methods to break up the algal cell wall effectively and measure the success by protein and carbohydrate release. Subsequently, we investigate algal cell wall features playing a role in the wall’s recalcitrance towards disruption. Using different mechanical and chemical technologies, alkali catalyzed hydrolysis of the Chlorella vulgaris cells proved to be especially effective in solubilizing up to 56 wt% protein and 14 wt% carbohydrates of the total biomass. The stepwise degradation of C. vulgaris cell walls using a series of chemicals with increasingly strong conditions revealed that each fraction released different ratios of proteins and carbohydrates. A detailed analysis of the monosaccharide composition of the cell wall extracted in each step identified possible factors for the robustness of the cell wall. In particular, the presence of chitin or chitin-like polymers was indicated by glucosamine found in strong alkali extracts. The presence of highly ordered starch or cellulose was indicated by glucose detected in strong acidic extracts. Our results might help to tailor more specific efforts to disrupt Chlorella cell walls and help to valorize microalgae biomass.

Trafficking Processes and Secretion Pathways Underlying the Formation of Plant Cuticles

Cuticles are specialized cell wall structures that form at the surface of terrestrial plant organs. They are largely comprised lipidic compounds and are deposited in the apoplast, external to the polysaccharide-rich primary wall, creating a barrier to diffusion of water and solutes, as well as to environmental factors. The predominant cuticle component is cutin, a polyester that is assembled as a complex matrix, within and on the surface of which aliphatic and aromatic wax molecules accumulate, further modifying its properties. To reach the point of cuticle assembly the different acyl lipid-containing components are first exported from the cell across the plasma membrane and then traffic across the polysaccharide wall. The export of cutin precursors and waxes from the cell is known to involve plasma membrane-localized ATP-binding cassette (ABC) transporters; however, other secretion mechanisms may also contribute. Indeed, extracellular vesiculo-tubular structures have recently been reported in Arabidopsis thaliana (Arabidopsis) to be associated with the deposition of suberin, a polyester that is structurally closely related to cutin. Intriguingly, similar membranous structures have been observed in leaves and petals of Arabidopsis, although in lower numbers, but no close association with cutin formation has been identified. The possibility of multiple export mechanisms for cuticular components acting in parallel will be discussed, together with proposals for how cuticle precursors may traverse the polysaccharide cell wall before their assimilation into the cuticle macromolecular architecture.

Innovative energy efficient thermal insulation to ensure indoor comfort in nZEB buildings

The paper presents the analysis of water and heat transfer through walls being thermally insulated with vegetal materials. The analysis identifies the risk for condense accumulation in the outer layers of external walls of a common residential building located in the coldest climatic regions of Romania. Different wall structures and insulation thicknesses are systematically considered with statistical extreme temperature and humidity outdoor values. Results are useful in designing nZEB individual houses with green and sustainable technologies that also provide energy savings and indoor conditions for good comfort and health in these desired building concept.

Assessment of Embodied Energy and Environmental Impact of Sustainable Building Materials and Technologies for Residential Sector

The energy demand of developing countries increases every year. Large amounts of energy are consumed during the production and transportation of construction materials. Conservation of energy became important in the perspective of limiting carbon emissions into the environment and for decreasing the cost of materials. This article is concentrated on some issues affecting the embodied energy of construction materials mainly in the residential sector. Energy consumption in three various wall structures has been made. The comparison demonstrated that the embodied energy of traditional wall structures is 3-times higher than the energy efficient building materials. CO2 emissions produced by conventional materials and green building materials are 54.96 Kg CO2/m2 and 35.33 Kg CO2/m2, respectively. Finally, the results revealed substantial difference in embodied energy and carbon footprints of materials for which its production involves a high amount of energy consumption.

AtSYP71 Is Important for Plant Cell Wall Biosynthesis and Stress Adaptation.

Background: SYP71, the plant-specific Qc-SNARE protein, is reported to regulate vesicle trafficking. SYP71 is localized on the ER, endosome, plasma membrane and cell plate, suggesting its multiple functions. Lotus SYP71 is essential for symbiotic nitrogen fixation in nodules. AtSYP71, GmSYP71 and OsSYP71 are implicated in plant resistance to pathogenesis. To date, SYP71 regulatory role on plant development remain unclear.Results: AtSYP71-knockout mutant atsyp71-4 was lethal at early development stage. Early development of AtSYP71-knockdown mutant atsyp71-2 was delayed, and stress response was also affected. Confocal images revealed that protein secretion was blocked in atsyp71-2. Transcriptomic analysis indicated that metabolism, response to environmental stimuli pathways and apoplast components were influenced in atsyp71-2. Moreover, the contents of lignin, cellulose and flavonoids as well as cell wall structures were also altered.Conclusion: Our findings suggested that AtSYP71 is essential for plant development. AtSYP71 probably regulates plant development, metabolism and environmental adaptation by affecting cell wall homeostasis via mediating secretion of materials and regulators required for cell wall biosynthesis and dynamics.

Engineering Method for Calculating the Temperature on the Inner Surface of the Outer Corner of a Building

Постановка задачи. Температура на внутренней поверхности наружного угла всегда меньше, чем по глади наружной стены, что при низких температурах наружного воздуха может приводить к образованию конденсата на внутренней поверхности стены. В связи с этим актуальным является проблема разработки инженерного метода расчета температуры в наружном углу для исключения возможности конденсатообразования на внутренней поверхности угла на стадии проектирования стеновых конструкций. Результаты. Для решения этой задачи на основе решения уравнения теплового баланса, учета амплитуды колебания температуры воздуха в помещении и теплопоглощения внутренних поверхностей стен, междуэтажных перекрытий (поверхности потолка и пола), перегородок, окон получена формула для вычисления температуры на внутренней поверхности наружного угла. Также в ходе исследования проведены натурные испытания стеновой конструкции с наружным углом и получены значения температур на внутренней и наружной поверхностях. Выводы. Сопоставление результатов расчетов по разработанной методике и экспериментальных данных показало, что значения температур на внутренней поверхности наружного угла практически совпадают. Это дает основание использовать предложенный инженерный метод расчета температуры на внутренней поверхности угла наружной стены при проектировании ограждающих конструкций зданий для создания благоприятных комфортных и санитарно-гигиенических условий в помещении. Statement of the problem. The temperature on the inner surface of the outer corner is always lower than on the inner surface of the outer wall. This temperature difference might lead to the formation of condensation on the inner surface of the wall at low outdoor temperatures. Therefore the problem of developing an engineering method for calculating the temperature in the outer corner to exclude the possibility of condensation on the inner surface in the design process of the outer wall structures is extremely relevant. Results. To address this problem, based on solving the heat balance equation, taking into account the amplitude of air temperature fluctuations in the room and heat absorption of the inner surfaces of walls, intermediate bottoms (ceiling and floor surfaces), parting walls, a formula was obtained to calculate the temperature on the inner surface of the outer corner. Also, through the course of the study, natural tests of the wall structure with an outer corner were carried out and the temperatures on the inner and outer surfaces were obtained. Conclusions. Comparison of the calculation results using the developed engineering calculation method and experimental data showed that the temperatures on the inner surface of the outer corner almost coincided. This makes it possible to use the suggested engineering method for calculating the temperature on the inner surface of the outer wall corner in the design of enclosing structures to exclude condensation.

Out from under the wing: reconceptualizing the insect wing gene regulatory network as a versatile, general module for body-wall lobes in arthropods

Body plan evolution often occurs through the differentiation of serially homologous body parts, particularly in the evolution of arthropod body plans. Recently, homeotic transformations resulting from experimental manipulation of gene expression, along with comparative data on the expression and function of genes in the wing regulatory network, have provided a new perspective on an old question in insect evolution: how did the insect wing evolve? We investigated the metamorphic roles of a suite of 10 wing- and body-wall-related genes in a hemimetabolous insect, Oncopeltus fasciatus . Our results indicate that genes involved in wing development in O. fasciatus play similar roles in the development of adult body-wall flattened cuticular evaginations. We found extensive functional similarity between the development of wings and other bilayered evaginations of the body wall. Overall, our results support the existence of a versatile development module for building bilayered cuticular epithelial structures that pre-dates the evolutionary origin of wings. We explore the consequences of reconceptualizing the canonical wing-patterning network as a bilayered body-wall patterning network, including consequences for long-standing debates about wing homology, the origin of wings and the origin of novel bilayered body-wall structures. We conclude by presenting three testable predictions that result from this reconceptualization.