Development of productivity assessment methodology for concreting process

Suhad M. Abd, Abbas M. Abd, Muhammad Fauzi Hj. Mohd Zain and Amiruddin Ismail

In spite of the development in construction industry; the productivity in this sector still considered as critical factor for most construction firms in developing and semi developing countries. In order to develop the productivity, several measures have been taken for some construction projects. This study highlights the topics of productivity monitoring and measurement in constructing sector. Performance measurements used to monitor the construction processes and activities. Building projects are taken as case study to show how these concepts can be used to analyze and develop the productivity of some options in this sector. Concreting process is taken as case study.  The results pointed to the relative importance of this activity in terms of time and cost. A comparative model has been developed to determine the best method of construction, its cost and duration. This model can also be used as a predicting tool for selecting the method during the planning phase of project.

A novel approach towards six-step operation in overmodulation region in SVPWM VSI

Anurag Tripathi, Bharti Dwivedi and Dinesh Chandra

Over modulation switching enables the operation of an inverter beyond the normal region, unto the six-step range.  As volt-sec compensation is not possible in every sampling period, it is achieved in every sector of operation in overmodulation. The approach presented here segregates the OVM switching into two modes namely, Mode-I and Mode-II.  In Mode-I, the required fundamental volt-sec compensation is obtained in every sector by reducing the switching times of the zero voltage vectors and a proportionate increase in the switching times of the active voltage vectors.  This process continues until the modulation index of 0.977 beyond which the zero vector switching region is exhausted. In Mode-II, a systematic pattern of switching is proposed, that gets modified with the increasing modulation index. Such switching patterns minimize switching on one hand and give a better harmonic spectrum on the other. The operation of the extended range of mode I and the smooth transition into mode II and six-step is verified using simulation results.

Physical and bending properties of injection moulded wood plastic composites boards

H’ng Paik San, Lee Ai Nee and Hang Chit Meng

There is increasing number of companies producing wood-plastic composite for structural applications. However, wood plastic composite (WPC) require solving two major constraints; technique and formulation before their design value for structural application can be determined. This study focused on solving the two major constraints by employed injection moulding method to produce WPC and using different commercial available coupling agents at different percentage to produce WPC. The effect of wood to plastic ratio was also evaluated on WPC produced using the coupling agents that gave highest bending properties. Commercial polypropylene wood fine and coupling agents premixed in dumper mixer for 30 minutes prior to extrusion process at temperature of 190oC using 110 mm counter-rotating twin-screw extruder. The WPC boards with size of 150 mm x 150 mm x 3 mm were then injection moulded by 40-ton press moulding machine. From the result, WPC produced from coupling agents Exxelor PO 1020 at 4% significantly performed better in bending properties. Further study on the effect of Exxelor PO 1020 percentage and the wood to plastic ratio showed that, WPC with 65% wood fine performed significantly better in MOR and MOE than other type of WPCs. WPC with 60% wood fine had significantly lower thickness swelling and water absorption compared to those 65% and 70% wood fine WPC. Conclusively, WPC with 65% wood fine is optimum content for WPC to produce from injection moulded method. Higher coupling agent percentage used in WPC formulation gave higher bending properties.

Strength and durability properties of concrete containing quarry rock dust as fine aggregate

R. Ilangovana, N. Mahendrana and K. Nagamanib

Common river sand is expensive due to excessive cost of transportation from natural sources. Also large-scale depletion of these sources creates environmental problems. Use of Quarry rock dust as a fine aggregate in concrete draws serious attention of researchers and investigators. This paper presents the feasibility of the usage of Quarry Rock Dust as hundred percent substitutes for Natural Sand in concrete. Mix design has been developed for three grades using design an approach IS, ACI, USBR, RN. No.4 and BRITISH for both conventional concrete and quarry dust concrete. Tests were conducted on cubes and beams to study the strength of concrete made of Quarry Rock Dust and the results were compared with the Natural Sand Concrete. An attempt has also been made to durability studies on Quarry Rock Dust when compared with the Natural Sand concrete. It was found that the compressive, flexural strength and durability studies of concrete made of Quarry Rock Dust are nearly 10% more than the conventional concrete.

Experimental and analytical study on chip formation mechanism in machining of DRACs

Raviraj Shetty, Laxmikanth Keni, R. Pai and V. Kamath

It is known from the theory of metal cutting that an examination of machining chips provides the cheapest and the most effective way of understanding the machining characteristics of a material. The review of literature on machining of DRACs reveals that these aspects have been given relatively little attention during the machining studies. This viewpoint has provided motivation for the study of fundamental aspects of machining of composites involving chip formation mechanism experimentally and analytically. This paper discusses experimental work and finite element analysis to investigate the mechanism of chip formation during machining of DRACs. Focus of this paper is on understanding the influence of different cutting parameters on mechanism of machining. Chips generated experimentally and by finite element modeling during orthogonal machining of DRACs were used for this purpose.

Performance comparison of open and closed loop operation of UPFC

Sarat Kumar Sahu, S. Suresh Reddy and S. V. Jayaram Kumar

Abstract:

Controlling power flow in modern power systems can be made more flexible by the use of recent developments in power electronic and computing control technology. The Unified Power Flow Controller is a FACTS device that can control all the three system variables namely, line reactance, magnitude and phase angle difference of the voltages across the line. The Unified Power flow controller provides a promising means to control power flow in modern power systems. Essentially, the performance depends on proper control setting achievable through a power flow analysis program. This paper addresses comparison of the two steady-state modeling of U.P.F.C within the context of Load flow study of a power system. This model is incorporated into an existing Newton-Raphson Load flow algorithm.

Testing and performance evaluation of an imported mobile bucket milking machine for water buffaloes

Jandool Khan

An imported mobile bucket milking machine was used for milking water buffaloes. The experiment was conducted at Livestock Research Station (LRS), National Agricultural Research Centre, Islamabad . A herd of 12 animals (water buffaloes) were milked for more than one year. Machine milking of buffaloes was the first experience of its kind in Pakistan . The results were encouraging. Type and length of stimulation phase, size of teat cup liner, suited vacuum level, weight of milking cluster, milk capacity of claw piece, way of attachment of cluster and milking with single and double clusters were included as variables. The best suited size of teat cup liner for the milked animals was 25mm in diameter among the liners used. The 2.1kg cluster which was having light teat cup shells and stainless steel claw piece proved to be superior for the smooth and sponge like teats. The vacuum level 46-48kPa and 44-46kPa gave maximum milk yield (0.807 and 1.086 liters per minute) for single and double clusters, respectively.

Performance of a three-phase fluidized bed reactor with different support particles in treatment of dairy wastewater

A. Arumugam and P. L. Sabarethinam

Abstract:

The aerobic treatment of dairy wastewater was performed experimentally in a three phase fluidized-bed bioreactor (FBBR) using culture of living cells immobilized on support particles. The characteristics of dairy wastewater were studied. The performance of a three phase fluidized bed bioreactor with ceramic, Teflon, glass supports was studied and compared. Pure culture of immobilized cells of Candida haemulonii was used. It was observed that increase in surface roughness of support particle increases the degradation rate of the wastewater. The optimum bed height for the maximum COD reduction for ceramic particle was found to be 7cm. The results showed that percentage reduction in COD for ceramic, Teflon and glass particles are 91%, 85% and 78%, respectively.

Effects of pre-treatment condition on the yield and quality of Neem oil obtained by mechanical pressing

Felycia Edi Soetaredjo, G. M. Budijanto, R. I. Prasetyo, and N. Indraswati

Abstract:

Neem (Azadirachta indica A. Juss) is one of the very few trees known in the Indian subcontinent. Neem seed is a part of Neem tree which has high concentration of oil. Neem oil extraction using mechanical pressing is the cheapest method, and some pretreatment such as heating influenced its yield and physical and chemical characteristics. The quality of Neem oil extracted by mechanical pressing was changed during storage. The results of this experiment showed that the optimum pressure for mechanical pressing of Neem seed was 5000 psi. The pretreatment heating on the Neem seed particles and storage caused the oil quality reduced, therefore room temperature was found to be the recommended temperature for the Neem oil extraction using mechanical process.

Hybrid (solar and wind) energy systems for rural electrification

M. Muralikrishna and V. Lakshminarayana

Abstract:

Hybrid power system can be used to reduce energy storage requirements. The influence of the Deficiency of Power Supply Probability (DPSP), Relative Excess Power Generated (REPG), Energy to Load Ratio (ELR), fraction of PV and wind energy, and coverage of PV and wind energy against the system size and performance were analyzed. The technical feasibility of PV-wind hybrid system in given range of load demand was evaluated. The methodology of Life Cycle Cost (LCC) for economic evaluation of stand-alone photovoltaic system, stand-alone wind system and PV-wind hybrid system have been developed and simulated using the model. The comparative cost analysis of grid line extension energy source with PV-wind hybrid system was studied in detail. The optimum combination of solar PV-wind hybrid system lies between 0.70 and 0.75 of solar energy to load ratio and the corresponding LCC is minimum. The PV-wind hybrid system returns the lowest unit cost values to maintain the same level of DPSP as compared to standalone solar and wind systems. For all load demands the levelised energy cost for PV-wind hybrid system is always lower than that of standalone solar PV or wind system. The PV-wind hybrid option is techno-economically viable for rural electrification.

Integrating Error Detection with data encryption algorithm using Permutation Invariant RAO Alaka Shift transform

A.V. Narasimha Rao, K. Soundara Rajan and K. Srinivasa Rao

Abstract:

This paper adopts a novel approach for ensuring security of data with error detection capability. RAS Transform is a nonlinear recursive Transform. This simple but very effective RAS transform is Permutation Invariant and used to code the digital data at two levels, so that the data is encrypted and also there is multilevel error detection mechanism based on the properties of the RAS Transform. The first type is data independent and the later is data dependent. In data dependant encryption, the partially encrypted data is subjected to RAS Transformation at two levels namely, byte level and block level before transmission. The outcome is 128 bits of encrypted data together with Encryption Key. A code book of only 20 valid code words is generated to represent 256 possible octets of 8-bit data words.  From each of the code words, the data word can be uniquely recovered using the data dependent symmetric encryption key. The result of this coding on a sample text data of about 189 characters size is presented.

An experimental study on the effect of welding parameters on mechanical and microstructural properties of AA 6082-T6 friction stir welded butt joints

G. Raghu Babu, K. G. K. Murti and G. Ranga Janardhana

Abstract:

The effect of processing parameters on mechanical and microstructural properties of aluminium alloy 6082-T6 Friction stir-welded (FSW) joints were investigated in the present study. Different welded specimens were produced by employing variable rotating speeds and welding speeds. Tensile strength of the produced joints was tested at room temperature and the correlation with process parameter was assessed. Microstructures of various zones of FSW welds are presented and analyzed by means of optical microscopy and microhardness measurements. Several studies have been conducted to investigate the properties and microstructural changes in Friction Stir Welds in the aluminium alloy 6082-T6 in function of varying process parameters. The experimental results indicated that the process parameters have a significant effect on weld macrostructure and mechanical properties of joints.

Emissions and performance study with sunflower methyl ester as diesel engine fuel

Sudhir Ghai, L. M. Das and M. K. Gajendra Babu

Abstract:

There is a need for innovative thinking to stabilize the fuel consumption pattern as well as depletion rate of crude oil and natural gas resources. Also, there are concerns ranging from environmental degradation as a result of tremendous noxious tail pipe emissions (CO, SOx, NOx, HC, SPM, aromatic compounds etc) to global warming due to emission of GHG (i.e. CO2) from petrol & diesel driven vehicles. Thus there are strong incentives to adopt renewable energy in the form of biofuels-alcohols and biodiesels both, in transport sector in the service of the nation. In this research study ‘Methyl ester of Sunflower oil’ which is also popularly known as biodiesel, was prepared by employing transesterification of sunflower vegetable oil with methanol and catalyst KOH. Various blends of Sunflower methyl ester (SFME) were tested in 4-S, C.I. engine and engine performance results obtained were compared with data obtained from pure diesel (HSD). Study reported 1.5 to 4% increase in brake thermal efficiency (BTE) with SFME blends. The brake power (BP) values were comparable to those obtained from HSD. With biodiesel blends, significant reduction in emissions of hydrocarbons as well as smoke/ (particulates) was noticed. NOx emissions with SFME blends were observed to be somewhat higher as compared to diesel. Since biodiesel is sulphur free fuel, no SOx emissions were produced.

Features of waste water quality in Zongguan water plant

Hadi Naba Shakir

Abstract:

This paper takes waste water from Zongguan waterworks as a research object. The waste water was monitored consecutively and found that: the SS of waste water was more than 90 times of which in original water, COD was more than 30 times, and Fe was 58 times. The SS and turbidness showed no linear relation except when they were lower. The SS and Fe accord with linearity relation was better. The difference between waste water that from overhead crane at the beginning and in the end was wide. Although the flux of backwash wastes was small but the impact of it over the quality of water was very high.