Research on deformations which appear in within the metal structures of mining equipment

Metal structures of the mining equipment are made of a steel with good weldability and mechanical characteristics corresponding and namely St 52.3 steel that allows the use of these metal structures in heavy duty. Metal structures of the mining equipment are very large structures and strong requested mechanical, and in these conditions during exploitation can occur large deformations at these that may cause a decrease in the exploitation safety of mining equipment. Research has followed in principal the analyze of deformations appear in metallic structures, and for realizing the researches has been used both a dimensional analysis and one that is based on the finite element method

ELECTROCOAGULATION IN WASTEWATER TREATMENT

Within the past decades,water scarcity is one of the greatest challenges faced by humans, sothe treatment and reuse of wastewater generated daily from household, sanitary and industrial activities iswidely practiced and encouraged.Electrocoagulation has emerged as an effectivetechnology for the treatment ofdifferent categories of wastewater. The electrode materials should non-toxic to human health and environment and these usually involve aluminium or iron, but new materials are also used.The efficiency of electrocoagulation depends on current density, gap between anodes and cathodes, electrodes arrangement, composition and shape, initial pollutant concentration, composition and pH of the solution, electrolysis time.This paper aims to reviewthe mechanisms involved in wastewater electrocoagulationand the results of electrocoagulation applied in the treatment of wastewater from different sources

The optimization of welding regime parameters at shielded metal arc welding (SMAW) by mathematical modeling

The realized researches followed the determining of mathematical models that allow the optimization of the welding process in order to obtain welded joints with certain values of the mechanical characteristics. Thus, there were established mathematical models of dependence of mechanical characteristics of welded joints (Rm, Rp02, Z, A, KCV 20°C) of each parameter of welding regime (Iw, Uw), and also, mathematical models that offer cumulative dependence of mechanical characteristics of both parameters of welding regime.The researches have been carried out using steel E 36-4 as base material and as filler material basic electrodes, type E7018 and the applied welding procedure was the process: shielded metal arc welding (SMAW)

Study on stability at work for tillage aggregates

This paper shows the importance of stability at work for tillage aggregates, from the point of view of work quality and fuel consumption. The classic ploughing aggregates are analysed, from the point of view of stability at work, as agricultural milling cutler and aggregate plough – agricultural milling cutler, accentuating the way in which the soil reaction on socket-rod can be influenced. The value of socket-rod pressure on the vertical furrow wall must be optimized, because a higher value for this force leads to the friction force increase and to the destruction of the vertical wall, while a smaller value leads to the aggregates instability at work. From this point of view, the aggregate made of plough and milling cutler carries under all the stability conditions

Metabolic alterations in experimental models of depression

Introduction: Major depressive disorder is one of the most prevalent psychiatric disorders and is associated with a severe impact on the personal functioning, thus with incurring significant direct and indirect costs. The presence of depression in patients with medical comorbidities increases the risks of myocardial infarction and decreases diabetes control, and adherence to treatment. The mechanism through which these effects are produced is still uncertain. Objectives of this study were to evaluate the metabolic alterations in female Wistar rats with induced depression, with and without administration of Agomelatine. The methods included two experiments. All data were analyzed by comparison with group I (control), and with each other. In the first experiment we induced depression by: exposure to chronic mild stress-group II; olfactory bulbectomy-group III; and exposure to chronic mild stress and hyperlipidic/ hyper caloric diet-group IV. The second experiment was similar with the first but the rats received Agomelatine (0.16mg/ animal): group V (depression induced through exposure to chronic mild stress), VI (depression induced through olfactory bulbectomy) and VII (depression induced through exposure to chronic mild stressing hyperlipidic/ hypercaloric diet). Weight, cholesterol, triglycerides and glycaemia were measured at day 0 and 28, and leptin value was measured at day 28. The results in the 1st experiment revealed significant differences (pconclusion, significant correlations were found between high level of triglycerides and depression induced by chronic stress and olfactory bulbectomy. Agomelatine groups had a lower increase of triglycerides levels

Researches on corrosion cracking phenomenon that occurs on welded of agricultural equipment

Welded construction equipments for agriculture are strongly stressed in terms of mechanics, but also in terms of environmental action and thus in many cases appears their wear by corrosion cracking phenomenon. After research it was noted that after a certain period of use of equipment, metallographic structure of welded steel structures has changed substantially and at the same time a change in the chemical composition of steel was also observed. In terms of chemical composition a reduction in carbon content was mainly observed, and an increase in sulfur content,determined mainly by the presence of large quantities of sulfur in the atmosphere. This sulfur in the atmosphere at the same time determines the acid action on metallic materials, by forming with water from precipitation of H2S. Key words

PRODUCTION STATUS OF BIOMASS PELLETS – REVIEW

The use of biomass has become extremely important for the production of clean energy from renewable sources. This is due to the continuously increased need for energy, to the possible depletion of conventional fossil fuels in the near future, and also to the regulations of European Union on the need to reduce significantly the emissions of greenhouse gases. This paper presents a synthesis on the raw materials used for pellets production, some of the important characteristics of pellets (density, ash content and heating power), and also data on the status of pellets production and consumption in different countries. Latest reported data show that the European Union is the biggest wood pellets producer globally, with a production of 13.5 million tonnes in 2014. Romania’s pellets production in 2014 was of 740000 tonnes, and estimations are that in 2020 it will exceed 1.2 million tonnes