Recycling and Recharging of Supreme Garnet in Abrasive Waterjet Machining

Abrasive waterjet (AWJ) technology is widely used for cutting technical materials, cleaning contaminated surfaces, polishing hard-to-machine materials, etc. However, its main disadvantage is high cutting cost. Therefore, recycling and recharging abrasives used in the AWJ cutting process have been subject to many studies. This chapter presents a study on the recycling and recharging of Supreme garnet (or IMC garnet) in abrasive waterjet machining. In this study, the reusability of the recycled and recharged garnet was explored. Also, the cutting performance and the cutting quality of the recycled and recharged abrasive were investigated. Finally, the optimum particle size for recycling and recharging was found

Total Factor Productivity Growth, Technical Progress and Efficiency Change in Vietnam Coal Industry – Nonparametric Approach

This research applies Data Envelopment Analysis (DEA) approach to analyse Total Factor Productivity (TFP) and efficiency changes in Vietnam coal mining industry from 2007 to 2013. The Malmquist productivity measures were decomposed into two components: technical change index and efficiency change index. The results indicate that TFP of Vietnam coal mining firms decreased due to slow technological progress and unimproved efficiency. The decadence of technical efficiency in many firms proved that the coal mining industry has a large potential to increase productivity through technical efficiency improvement. Enhancing human resource training, technology and research & development investment could help the industry to improve efficiency and productivity in Vietnam coal mining industry. Keywords: Technical and Scale Efficiency, Total Factor Productivity, Nonparametric Techniques, Vietnam. JEL Code: O47, O50 DOI: 10.7176/EJBM/11-12-16 Publication date: April 30th 201

Some Overviews on Organic Agriculture Apply Circular Economy

The paper provides an overview on agriculture apply circular economy (CE). It provides the concepts of circular economy and organic agriculture. The paper used secondary researches from topics, documents related to organic agriculture apply CE. With results which the previous studies mentioned, the paper bases on different CE theoretical approaches to clarify the concept of organic agriculture in the direction of circular economy. Keywords: organic agriculture, circular economy DOI: 10.7176/JESD/13-20-01 Publication date:October 31st 202

Energy cost savings based on the UPS

Energy-saving, improving energy efficiency, and finding a new efficient way to use energy are considered as an urgent problem in over the world. In this paper, we consider the economics of energy use in combination with energy storage units where two forms of electricity exist in the power system. Then the problem of optimizing the installation capacity (to optimize the investment costs for energy storage) is presented and investigated in connection with the conversion systems. The topic opens a very significant result, including the introduction of a mathematical model to calculate the simulation in optimizing the installation capacity of the equipment in the system, multi-source power, as well as voltage and power stability benefits

Influence of Ba[Mg2Al2N4]Eu2+ phosphor particle size on optical properties of the 6000K CPW-LEDs

In this paper, we consider the red phosphor Ba[Mg2Al2N4]Eu2+ as the novel recommendation for improving the optical properties of the 6000K conformal packaging WLEDs (CPW-LEDs). For this purpose, we investigate the influence of the Ba[Mg2Al2N4]Eu2+ particle size on the optical properties in terms of CCT, CQS, CRI, and LO using the Light Tools and Mat Lab software. From the research results, it can be observed that the optical properties of the 6000K CPW-LEDs are significantly influenced by the size of the Ba[Mg2Al2N4]Eu2+ particle. The CRI and CQS increase from 65 to 67 and 64 to 68 while the size of the Ba[Mg2Al2N4]Eu2+ particle varies from 1 μm to 10 μm, respectively. This research can provide a novel recommendation for LEDs industry at this time

Flexible Pavement Life Cycle Cost Analysis by Using Monte-Carlo Method and the Suggestions for Developing Countries

Flexible road pavement plays an essential role in developing an effective, economic, and safe operation road network of any country. In Vietnam, a developing country, the selection of a suitable flexible pavement structure is always a challenge due to fiscal limitations. The traditional determinant method (TDM) by which pavement structures are selected mainly on the basis of initial construction costs and traffic load has been used for many years in the nation. This paper presents the use of Monte Carlo simulation to analyze the entire flexible pavement life cycle cost. Data including initial and maintenance costs and road user costs were collected from several different types of existing flexible pavement in Nghe An province, Vietnam. Random variations of several main inputs were explored in order to develop density distribution functions. These functions then were used as the bases for Monte Carlo simulation. One million simulation runs were implemented and the Net Present Values (NPVs) among pavement types were compared under the light of risk analysis. Research results showed that TDM method provided bias and uncertain results compared to that of Monte Carlo one. In terms of long- term pavement performance, a low-cost pavement structure should not always be considered as a wise selection. Some other suggestions for a developing country as Vietnam were also included

Novel dependencies of currents and voltages in power system steady state mode on regulable parameters of three-phase systems symmetrization

The unbalanced mode, negative/zero sequence, variation of real power are caused by the nonlinear or unbalanced loads increase the power transmission losses in distributing power systems and also harmful to the electric devices. Reactive power compensation is considered as the common methods for overcoming asymmetry. The critical issue in reactive power compensation is the optimal calculation of compensation values that is extremely difficult in complex circuits. We proposed a novel approach to overcome these difficulties by providing the creation of new analytical connections of the steady-state mode parameters (voltages, currents) depends on the controlled parameter for the arbitrary circuits. The base of our approach to reactive power compensation is the fractional-polynomial functions. We present a new description of the behavior of voltages and currents depending on the controlled parameters of the reactive power compensation devices, and we prove its effectiveness