NOPR Collection:

Photovoltaic Based Three-Phase Three-Wire DSTATCOM to improve Power Quality

2013-07-01T00:00:00Z

Title: Photovoltaic Based Three-Phase Three-Wire DSTATCOM to improve Power Quality Authors: Kannan, V. Kamatchi; Rengarajan, N. Abstract: Three-phase three-wire Distribution Static Compensator (DSTATCOM) with Photovoltaic (PV) array or battery operated DC-DC boost converter is proposed in this paper. The proposed DSTATCOM consists of a three-leg Voltage Source Converter (VSC) with a DC bus capacitor and it provides continuous reactive power compensation, source harmonic reduction and load compensation throughout the day. With the help of PV array or battery, which is connected to the dc link of VSC via the DC-DC boost converter is used to maintain the desired voltage to the dc bus capacitor for continuous compensation to the load. The IcosФ controlling algorithm is proposed for three-phase three-wire DSTATCOM. In this algorithm, the fuzzy logic controller is compared with the conventional PI (Proportional Integral) controller at DC bus to regulate the DC link capacitor voltage. The fuzzy controller is used to maintain the DC link voltage to the reference value. The switching of VSC will occur by Hysteresis based Pulse Width Modulation (PWM) current controller. The simulations are carried out by using MATLAB/simulink software to demonstrate the effectiveness of the proposed scheme. Page(s): 446-453

Effect of rice husk ash on mechanical properties of low density polyethylene

2013-07-01T00:00:00Z

Title: Effect of rice husk ash on mechanical properties of low density polyethylene Authors: Louis, N Samson Maria; Thomas, Sabu Abstract: Rice husk ash (RHA) obtained from rice husk by burning at different temperatures was used at 10%, 20% & 30% by weight as a filler in low density polyethylene(LDPE) and the mechanical properties were studied. RHA when burned cleaned rice husk at 420^ºC (RHA 420) & 520^ºC (RHA 520) were amorphous and at 900^ºC (RHA 900) was less crystalline. There was no significant change in overall mechanical properties when LDPE was filled with even up to 30 % of RHA 420, RHA 520 & RHA 900 fillers respectively indicating the good LDPE-RHA interaction due to Si-OH groups. Page(s): 441-445

Optimal common cycle time for a multi-item production system with discontinuous delivery policy and failure in rework

2013-07-01T00:00:00Z

Title: Optimal common cycle time for a multi-item production system with discontinuous delivery policy and failure in rework Authors: Chiu, Yuan-Shyi Peter; Lin, Hong-Dar; Cheng, Feng-Tsung; Hwang, Ming-Hon Abstract: This study is concerned with the optimal common cycle time for a multi-item production system with discontinuous delivery and failure in rework. In real life manufacturing environments, managements often plan to produce multiple products in turn on a single machine in order to maximize machine utilization. Also, dealing with random defective items during production seems to be an inevitable task, and the multi-delivery policy is commonly adopted to distribute the finished products to buyers. The objective of this study is to determine the optimal common production cycle that minimizes the total production-inventory-delivery costs per unit time for a multi-item production system with failure in rework and multi-delivery policy. Mathematical modeling along with an optimization procedure is used to derive the optimal common cycle time for the aforementioned production problem. Page(s): 435-440

Biosorption of methylene blue on chemically modified Chaetophora Elegans algae by carboxylic acids

2013-07-01T00:00:00Z

Title: Biosorption of methylene blue on chemically modified Chaetophora Elegans algae by carboxylic acids Authors: Mikati, Farah; Jamal, Mouhiaddine El Abstract: Chemical modification of Chaetophora Elegans algae with carboxylic acids were undertaken in order to improve the methylene blue adsorption. The modified algae with 1 M acetic and formic acid showed an increase in the maximum uptake, but the modified algae with 1M oxalic acid showed an important decrease in the uptake from 143 mg g^-1 to 20 mg g^-1. The type and concentration of acid used in the chemical modification (0.1 M -1 M) is the major parameter affecting the maximum uptake. The carboxylic acids having more than one –COOH lead to cross-linking effect and so to decrease in q_max. Langmuir-Freundlich isotherm model fitted better the isotherm adsorption data for modified and unmodified algae. Pseudo second order model was well in line with the experimental data. The adsorption rate constant (K₂) is higher for modified algae with acetic acid than that of raw algae. The maximum uptake is independent of isotherm adsorption temperature in the range studied. Page(s): 428-434