Self-Tapping Screws without Pre-Drilling for Brazilian Reflorestation Species

2014 ◽  
Vol 1025-1026 ◽  
pp. 345-348
Author(s):  
Carlito Calil Neto ◽  
André Luis Christoforo ◽  
Marília da Silva Bertolini ◽  
Francisco Antonio Rocco Lahr ◽  
Carlito Calil Junior

Wood is a renewable source of structural material with high relative strength/weight, low energy production, which kidnaps and stores carbon in its production. The large use of wood is due to its special qualities as raw material for other products manufactured in residential construction or major works such as bridges, has been widely used in roofing for industrial and commercial buildings. Commercially there are limitations on the length of the wood, resulting from the extraction of tree trunks, thus requiring the adoption of binding elements is the use of self-tapping screws efforts required by side and which can be axial, shear, tensile or compression. Whereas in Brazil does not yet exist and the promising future of the product, this research aims to study the behavior of self-tapping screws together with Brazilian reforestation species ofPinusoocarpaandLyptus(softwood and hardwood). Rothoblaas self-tapping screws had a good penetration in both woods without requiring pre-drilling, the species of Lyptus wood showed the highest values of strength and the inclination of the screws, at 45 degrees showed the best results on either species of wood.

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Alberto Palma ◽  
Javier Mauricio Loaiza ◽  
Manuel J. Díaz ◽  
Juan Carlos García ◽  
Inmaculada Giráldez ◽  
...  

Abstract Background Burning fast-growing trees for energy production can be an effective alternative to coal combustion. Thus, lignocellulosic material, which can be used to obtain chemicals with a high added value, is highly abundant, easily renewed and usually inexpensive. In this work, hemicellulose extraction by acid hydrolysis of plant biomass from three different crops (Chamaecytisus proliferus, Leucaena diversifolia and Paulownia trihybrid) was modelled and the resulting solid residues were used for energy production. Results The influence of the nature of the lignocellulosic raw material and the operating conditions used to extract the hemicellulose fraction on the heat capacity and activation energy of the subsequent combustion process was examined. The heat power and the activation energy of the combustion process were found to depend markedly on the hemicellulose content of the raw material. Thus, a low content in hemicelluloses resulted in a lower increased energy yield after acid hydrolysis stage. The process was also influenced by the operating conditions of the acid hydrolysis treatment, which increased the gross calorific value (GCV) of the solid residue by 0.6–9.7% relative to the starting material. In addition, the activation energy of combustion of the acid hydrolysis residues from Chamaecytisus proliferus (Tagasaste) and Paulownia trihybrid (Paulownia) was considerably lower than that for the starting materials, the difference increasing with increasing degree of conversion as well as with increasing temperature and acid concentration in the acid hydrolysis. The activation energy of combustion of the solid residues from acid hydrolysis of tagasaste and paulownia decreased markedly with increasing degree of conversion, and also with increasing temperature and acid concentration in the acid hydrolysis treatment. No similar trend was observed in Leucaena diversifolia (Leucaena) owing to its low content in hemicelluloses. Conclusions Acid hydrolysis of tagasaste, leucaena and paulownia provided a valorizable liquor containing a large amount of hemicelluloses and a solid residue with an increased heat power amenable to efficient valorization by combustion. There are many potential applications of the hemicelluloses-rich and lignin-rich fraction, for example as multi-components of bio-based feedstocks for 3D printing, for energy and other value-added chemicals.


2019 ◽  
pp. 23-34
Author(s):  
Sheila Genoveva Pérez-Bravo ◽  
Ana María Mendoza-Martínez ◽  
Maria del Refugio Castañeda-Chávez ◽  
Luciano Aguilera-Vázquez

The energy demand of the world population is increasing due to population growth and technological development. The current energy base is a generator of CO2 emissions, the most abundant and main greenhouse gas responsible for global warming, as well as pollutants, sulfur oxides and nitrogen oxides. The environmental deterioration and the increase in fossil fuel prices make it necessary to investigate less aggressive energy sources with the environment at competitive costs in the market. Biofuels are an alternative for energy production due to their origin in the short carbon cycle, their emissions are considered almost zero, including biodiesel and bioethanol. The latter can be obtained from microalgae rich in carbohydrates and lipids, easy to grow in short periods of time. The objective of this research is to summarize the findings made about the existence of useful microalgae as raw material to produce biofuels in Mexican territory. An exhaustive review of the literature was carried out, which contributed to estimate the microalgal diversity in the country and its lipid contents as well as carbohydrates, with different species of the genera Chlamydomonas, Chlorella, Scenedesmus, Desmodesmus being found mainly.


2017 ◽  
Vol 14 (1) ◽  
pp. 85
Author(s):  
A.M. Algarny ◽  
I.M. Al-Naimi ◽  
M.A.M Alhefnawy

The paper promotes sustainable community through empowering the production and utilization of biomass renewable energy. The aim of this paper is to urge societies to adopt sustainable energy practices and resources; the objective is to appraise the possibilities of biomass energy produced through a neighborhood in Eastern Province, Saudi Arabia. The system incorporates an evaluation of the measure of biomass created, then utilizes two ascertaining techniques to gauge whether the measure of energy can be delivered. The computation strategies are hypothetical, with one drawn from past works and the other from a Biomass Calculation Template performed as part of the Evaluation of Biomass Resources for Municipalities study (EBIMUN) by the Waterford County Council. The outcomes demonstrate that the aggregate potential biogas generation of the study area is around 43,200 m3 /year, the methane mass is around 18,000 m3 /year, and the energy production amount is around 250 MWh/year. Contrasting the capability of biogas creation from both techniques, the figure assessed by EBIMUN is around 7,000 m3 /year less than the hypothetically computed amount. The figures suggest that biogas is worthy of consideration as a renewable source of energy. 


2015 ◽  
Vol 3 (2) ◽  
Author(s):  
Jordan Guillot ◽  
Adolfo Viloria

Los generadores eólicos son sistemas de producción de energía renovable, que adquieren su energía de la circulación del aire que pasa a través de sus aspas. Estos sistemas son muy usados a nivel mundial para la generación de energía, convirtiéndose en los más usados. Pero ellos como todos los sistemas de generación de energía renovable, poseen inconvenientes, como es la producción de energía cuando no hay flujo de viento, o como evitar el daño en las baterías por la carga y descarga en los sistemas autónomos. La figura de investigación teórica de laboratorio arrojo que todas estas interrogantes tienen una solución bastante sencilla que es la utilización de un sistema hibrido, el diseño de un sistema de elevación con poca energía para el transporte de la energía suministrada por aerogenerador y la creación de un controlador de carga hibrido especial con un control robusto al momento del suministro de energía. AbstractWind generators are systems of renewable energy production, which get their energy from the flow of air that passes through its blades. These systems are used worldwide to power generation, becoming the most used. But they and all systems of renewable energy generation, have drawbacks, such as energy production when there is no wind flow, or prevent damage to batteries by charging and discharging in autonomous systems. Figure theoretical research laboratory throw all these questions have a rather simple solution is to use a hybrid system, the design of a lifting system with low energy to transport the energy supplied by the wind turbine and the creation of a special hybrid charge controller with a robust control at the time of power supply. 


Author(s):  
Mykola Stadnik ◽  
Andrii Shtuts ◽  
Oleksandr Pylypenko

Ukraine has untapped potential for the production of own energy from renewable sources - processing of livestock waste (animal manure and bird droppings) with the formation of biogas, which can then be used to produce electricity, heat or fuel - analogues of natural gas (methane) (in particular, for own needs of farms). Currently in Ukraine, the generation of large amounts of waste on industrial farms is an environmental problem that needs to be addressed. Recycling livestock waste to generate biogas will partially solve environmental problems, as well as benefit from decentralized renewable energy production or fuel production. The role of renewable energy sources in energy production is constantly growing and now the issue of increasing the share of renewable sources in the energy balance of each country is relevant. In the supply of primary energy, the share of renewable energy accounts for 13% worldwide. Of these, biomass accounts for 10%, or 258 million tons per year, ie in the world biomass provides the largest share of energy supply from renewable sources. Domestic agricultural enterprises are significant consumers of fuel and energy resources, so they face the objective need to use alternative energy sources, including biofuels and the introduction of innovative energy-saving technologies. Biogas production is an efficient and attractive investment technology, due to the presence of significant raw material potential, favorable climatic and other. However, the level of introduction of this type of energy in the agro-industrial complex is insufficient, which is due to a number of issues, including insufficient level of practical recommendations for choosing power generators, their number, modes of operation taking into account daily energy consumption schedule, load and optimal efficiency. installations while providing autonomous power supply of the enterprise. This paper determines the level of energy supply of livestock farms through the use of biogas plants as a source of energy used for livestock waste.


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