Influence of ultrasonic agitation on the abrasive wear characteristics of Al-Cu/ 2 vol.% Grp composite

In the present study, the abrasive wear behavior of Al-4.4 wt.% Cu composite reinforced with 2 vol.% graphite particle (Grp) has been investigated. In the preparation of composite, Ultrasonic Treatment (UT) is provided in the composite melt for the uniform distribution of reinforcement particles. Two bond abrasive wear tests are conducted for composites treated with ultrasound and without UT and base alloy. The results of abrasive wear studies indicate that at 5 and 10 Newton (N) loads, the composite with UT has a higher coefficient of friction (COF) and wear resistance than that of the base alloy (Al-4.4 wt.% Cu). Whereas, at 15 and 20 N load, the value of COF and wear resistance is lower for the composite. Two abrasive wear mechanisms micro-plowing and micro-cutting have been observed during the wear tests of base alloy and composites. The analysis of worn-out sample surfaces at higher load reveals that softened material layer due to localized elevation in temperature between two contact surfaces during wearing acts as a tribolayer in base alloy while in composites both softened material layer and graphite layer have worked together as tribolayer.

Effect of the Layer Height on the Electrochemical Properties of Lithium-Sulfur Cell

One of the possible ways of manufacturing high-energy density lithium-sulfur batteries is to increase the height of the active material layer and thus increase the thickness of the electrode. The energy density frequently rises in tandem with the height of the active material layer; however, increased electrode thickness might result in a variety of negative consequences such as increased internal resistance of the cell, increased cell polarization, decreased porosity, or insufficient ion diffusion. The effect of the layer height of the positive electrode on the rate capability, energy density, and cycling behavior of the lithium-sulfur cells will be analyzed in this article.

Growth of Additive Manufacturing Due to Global Pandemic and its Effect on Supply Chain Management

Additive manufacturing is a revolutionary technology because of its ability to creates objects by adding material layer by layer rather than removing material from a block or by moulding procedure. Additive manufacturing has been around for more than three decades but still, traditional manufacturing is the dominant method for manufacturing. COVID-19 pandemic has been a torment globally and has brought distress and instability to the global economy. Due to this, the manufacturing sectors are badly affected. In this time of crisis, additive manufacturing has played a major role. This paper discusses the upsurge of Additive manufacturing due global COVID-19 pandemic and its worldwide impact on supply chain management.

Researching on influence factorsand value confirmation of elasticmodulus (Eac), layer coefficient (ai)of some types of hot dense asphalt concrete in Vietnam

The method of designing flexible road structures under the guidance of AASHTO 1993 was used in many states in the US and Canada and is being applied by many other countries in Europe and Asia. The layer coefficient ai in the AASHTO design equation represents an empirical relationship between the structural index SN and thickness. The value of the layer coefficients (ai) is specified for each material layer depending on the quality shown mainly through resilient modulus. This paper presents the initial research results of influencing factors and value confirmation of resilient modulus (Eac) and layer coefficients (ai) of some types of hot dense asphalt concrete in Vietnam.

Research into kinetics of filtration drying of alcohol distillery stillage

The article describes the results of experimental studies on kinetics of the filtration drying of corn distillery stillage, which has previously proven its effectiveness in drying other crops and various dispersed materials. The experimental data are presented in the form of graphical plots describing the change of material moisture over time depending on the temperature of the drying agent (60, 70, 80 and 900С) and the layer height (40, 80, 120 and 160 mm). The obtained results are analyzed and the changes that occur on the filtration drying curves depending on the change in the material layer height and drying agent temperature are described. It is shown that the filtration drying time of alcohol distillery stillage increases with increasing the material layer height. It is determined that the drying potential remains constant at the same parameters of the drying agent. It is shown that the rate of moisture removal during the filtration drying does not depend on the material layer height. It is found that the average residual moisture of corn alcohol distillery stillage is 3.140.06 wt.%; this value satisfies industrial needs for an increase in its shelf life and the possibility of long-term storage and transportation.

Improving the efficiency of detritus drying with the use of solar energy

In Ukraine, there is a problem of sewage sludge disposal. The volume of sediment is growing every year, and the existing silt sites of water supply systems are not able to accept their entire volume. At the same time, experts say that sludge in sewage treatment plants is not a problem, but an asset that can help farmers grow environmentally friendly products, because these fertilizers will have a number of advantages over chemicals: they can be cheaper, more useful and more efficient. At the same time, the processing of the so-called detritus (wet mixture of mineral and partially decomposed biological components) is complicated by the high initial humidity of the product. And according to the results of previous studies, if the humidity of the raw material is in the range of 45… 80 %, processing technologies can become economically feasible only if the intensification of its drying processes - as the most energy-intensive of technological processes. The aim of the work is to study the possibility of using renewable energy sources, in particular solar energy, to reduce energy consumption during pre-drying of wet material - one of the most important processes in the manufacture of granular fertilizers from waste treatment plants. A polycarbonate-coated greenhouse was used for sludge drying. The elongated side of the greenhouse is located in the east-west direction and has an angle of inclination to the horizon of 30°. The northern side of the roof covering is opaque and insulated. On the inside, it has a light-reflecting coating that directs rays at the material. The experiments were carried out in summer without additional heat, except for the heat of the sun. The experiments changed: weather conditions, the thickness of the material layer, the amount of mixing, the initial humidity of the material. Main results: Identified factors: - which lead to the most noticeable changes in the specific productivity of the laboratory dryer: ambient temperature, clarity-cloudiness; relative humidity in the environment, the amount of stirring, floor heating; - which do not lead to a significant impact: the thickness of the material layer, the initial humidity of the material. Key words: biomineral fertilizers, detritus, solar dryer