Paper Type	::	Review Paper
Title	::	Soft Switching Three Phase Push-Pull DC-DC Converter using Space-Vector PWM
Country	::	India
Authors	::	Hima Sudev || M.Murugan
Page No.	::	01-08
	::	10.9790/3021-03710108
		0.4/3021-03710108
		3021-0307-0108

In this paper, a SV-PWM Three-phase push-pull DC-DC Converter has been proposed. By using Space Vector-PWM, the output of the converter is increased when compared with the Sine-PWM.The three-phase DC-DC conversion increases the power density, uses the magnetic core of the transformer more efficiently and it reduces the stress on switches and require small filters since the frequency is higher when compared to single-phase topologies. An active clamping technique is employed by connecting the primary side of the transformer to the three-phase full bridge of switches and a clamping capacitor. The energy from the leakage inductances is reused in this circuit, thus efficiency of the converter is increased. The applications include fuel cell systems, transportation and uninterruptable power supplies that can benefit from the advantages presented by this converter.

[1]. R.Prasad, P.D.Ziogas, S.Manias, "Analysis and design of a three-phase off-line DC-DC converter with high frequency isolation," in Proc.IAS'88, 1988,pp.813-820.
[2]. L.D.Salazar, P.D.Ziogas, S.Manias, "Design oriented analysis of two types of three-phase high frequency forward SMR topologies", in Proc.Fifth Annual Applied Power Electronics Conference and Exposition, APEC'90,11-16/Mar.,1990,pp.312-320
[3]. R.W.A.A.De Doncker,D.M.Divan and M.H.Kheraluwala, "A three-phase soft-switched high-power-density DC/DC converter for high-power applications", IEEETrans.Ind.Applicat.,vol.27,pp.63-73,Jan/Feb.1991.
[4]. J.Jacobs, A.Averberg and R.De Doncker, "A novel three-phase DC/DC converter for high-power applications" in Proc.Power Electronics Specialists Conference,PESC 2004,Aachen,Germany,pp.1861-1867,vol.3.
[5]. D.S.Oliveira Jr. and I.Barbi, "A three-phase ZVS PWM DC/DC converter with asymmetrical duty cycle for high power applications",IEEETrans.PowerElectron.,vol.20,n.2,pp.370-377,Mar.2005.

Paper Type	::	Research Paper
Title	::	Control Of Heat Exchanger Using Internal Model Controller
Country	::	India
Authors	::	K.Rajalakshmi || , Ms.V.Mangaiyarkarasi
Page No.	::	09-15
	::	10.9790/3021-03710915
		0.4/3021-03710915
		3021-0307-0115

Heat exchanger is a device that exchange the heat between two fluids of different temperatures that are separated by a solid wall. The temperature gradient or the differences in temperature facilitate this transfer of heat. In General, temperature control system has the characteristics of non-linearity, large inertia and time variability. It is difficult to overcome the effects of these factors and get the satisfactory results by using the normal PID controller. Therefore, the PI, FOPID, FUZZY and IMC are the controllers implemented in this paper to control the output temperature of the heat exchanger system. The PI, FOPID, FUZZY and IMC are the controllers are compared, based on their overshoot and settling time the conclusions are given using simulation results. As a future work FOPID controller tuned using genetic algorithm will be implemented in this paper later for better effective temperature control over other controllers.

 

Keywords: - Internal model based controller, PID controller, Fuzzy controller and Shell and tube heat exchanger system.

[1]. Ian G Hom et.al, "Improved Filter Design in Internal Model Control," Ind. Eng. Chem. Res., vol. 35, no.10, pp. 3437-3441, Oct 1996.
[2]. Mridul Pandey, K. Ramkumar & V. Alagesan "Design of Fuzzy Logic Controller for a Cross Flow Shell and Tube Heat-Exchanger," IEEE, Mar 2012.
[3]. Subhransu Padhee, Yuvraj Bhushan Khare, Yaduvir Singh "Internal Model Based PID Control of Shell and Tube Heat Exchanger System,"IEEE, JAN 2011.
[4]. Kiam Heong Ang, Gregory Chong and Yun Li, "PID Control System Analysis, Design, and Technology," IEEE Trans., Control Syst. Technol., vol. 13, no. 4, pp. 559-576, Ju12005.
[5]. Ahmad Ali and Somnath Majhi, "PI / PID Controller Design based on IMC and Percentage Overshoot Specification to Controller design Set point Change," ISA Trans, 48, pp. 10-15, Jan 2009.

Paper Type	::	Research Paper
Title	::	Factor Analysis of Job Satisfaction in the Construction Industry
Country	::	Nigeria
Authors	::	E.O. Aiyewalehinmi
Page No.	::	16-24
	::	10.9790/3021-03711624
		0.4/3021-03711624
		3021-0307-0124

This paper presents a Factor Analysis (FA) carried out on the responses of the four major construction parties to the questionnaire. Involved are:management, employer's association, employees, and Construction Trade Union. Underlying the dimension (factors) of the responses data for the four parties are compared and findings are discussed. The influence of various contextual factors on some of these relationships and perceptions between/among the four major construction parties is investigated. A number of essential dimensions of workplace variables are identified which form the basis for developing both conceptual and research model. A significant understanding of group'sinsights of workplace communication and industrial relations(IR) is obtained. The purpose of factor analysis is to develop factors which identity the major dimensional differences within the data set. Finally, the study investigates the statistical reliability of the sample data; a reliability scale assessment indicates that results obtained from the statistical analysis are indeed valid.

 

Keywords: Satisfaction, Management, Employer's Association, Non-Management Employees and Union

[1]. Argyle, M. (1972) The social psychology of Work, HarmondsWorth, Middlesex, England; Penguin.
[2]. Hill, J. M. and Trist, E. L. (1955) "Change in Accidents and other Absences with Length of Services
Human Relations8, 121-152.
[3]. Maloney, F. and McFillen (1998) Workers Perceptions of Contractor Behaviour, Journal of
ConstructionEngineering; Vol. 113 No 3 ASCE.
[4]. Smith, R. and Roth, D. (1991) Safety Programs and Construction Manager, Journal of Construction
Engineering; Vol. 117 No4 360 – 371 ASCE.
[5]. Taffin, J. and McComick, E. J. (1996) Industrial London: Allen & UNWIN, Basic Book.

Paper Type	::	Research Paper
Title	::	Characterization of Some Selected Limestone Deposits in ogun State, Nigeria for Prediction of Penetration Rate of Drilling
Country	::	Nigeria
Authors	::	Okewale I.A ||, Olaleye B.M
Page No.	::	25-30
	::	10.9790/3021-03712530
		0.4/3021-03712530
		3021-0307-0130

The research correlated physical and mechanical properties with penetration rate of drilling in some typical limestone quarries in Ogun State, Nigeria. The work was carried out using the field data and rock samples collected from the two locations [Sagamu (A) and Ewekoro (B)]. Field data were used for the determination of penetration rate while rock samples were used for the laboratory analysis. The result of modal analysis from the thin section shows that sample A has the mineralogical composition of 79.5% calcite, 13.5% quartz and 7.0% opaque while sample B has 77.5% calcite, 17.0% quartz and 5.5% opaque. The average density, porosity and rebound hardness of samples from locations A and B as determined in the laboratory are 2.68g/cm3, 3.08%, 32.3 and 2.71g/cm3, 3.06%, 35.1 respectively. The result of Uniaxial Compressive Strength (UCS) as estimated from the correlation chart between average density and Schmidt hardness shows that location A has average strength of 61.8 MPa while B has 72.4 MPa. The point load strength index for location A has an average value of 1.6 MPa and B has an average value of 1.8 MPa while the tensile strength as estimated from point load strength index for A is 2.5 MPa and B is 2.7 MPa. The penetration rate as determined from field data shows that location A has an average penetration rate of 0.7 m/min and location B has an average penetration rate of 1 m/min. Statistical model was developed using Statistical Package for Social Sciences (SPSS) software and the result shows that there is a strong correlation between penetration rate and porosity, rebound hardness value and density. The result also shows that the porosity, rebound hardness value and UCS have negative influence on penetration rate while density has positive influence on penetration rate.

 

Keywords: - Characterization, limestone, physical properties, strength properties, correlation, penetration rate.

[1]. Adebayo, B., and Agbalajobi, S. A, Correlation of Rock Properties with Rotary DrillPenetration Rate in Limestone Quarry. Nigerian Mining Journal, 7(1), 2009, pp 1-9.
[2]. Busuyi, A.T., Optimization of Drilling and Blasting Operations in an Open Pit Mine,the SOMAIR experience Min. Sc. Tech. 19(6), 2009, pp. 736-739
[3]. Mc. Gregor, K,. The Drilling of Rock (London: C.R. Books Limited, 1967)
[4]. Beste U., Jacobsein S., and Hogmark S., Rock Penetration into Cemented CarbideDrill Buttons during Rock Drilling Wear, 264, 2007, pp 1142-1151
[5]. Onan, M. and Muftuoglu, Y.V., A Study of Drill Parameters and Penetration RatesRelationships in Gelik-44 borehole. 13th Mining Congress, Turkey. 1993, pp. 221-234

Paper Type	::	Review Paper
Title	::	A Vector Control Method for Three-Stage n-Level Cascaded Inverter with Performance Measurement.
Country	::	India
Authors	::	Reshmi P.S,|| A.Swarnalatha
Page No.	::	31-37
	::	10.9790/3021-03713137
		0.4/3021-03713137
		3021-0307-0137

This paper contains a three stage n-level hybrid inverter circuit and its control method. The three inverter stages are the high-, medium-, and low-voltage stages. The high voltage stage is a conventional three phase inverter which is used inorder to reduce the losses. The medium and low voltage stages are made of cascaded H-bridge inverters. The low voltage stage is controlled by using space-vector modulation for optimized efficiency and excellent output performance. In this, the number of inverter levels can be varied from 2 to 18 depending upon the application. The harmonic distortion gets reduced as the number of levels increases. Thus the inverter can be operated for any number of levels using this method. The simulation model of the system is created in the MATLAB/SIMULINK environment.

[1]. W. Yao, H. Hu, and Z. Lu, "Comparisons of space-vector modulation and carrier-based modulation of multilevel inverter", IEEE Trans. Power Electron., vol. 23, no. 1, pp.45-51, Jan. 2008.
[2]. A.K. Gupta and A.M. Khambadkone, "A general space vector PWM algorithm for multilevel inverters including operation in overmodulation range," IEEE Trans. Power Electron., vol.22, no. 2,pp. 517-526, Mar.2007.
[3]. C. Rech, H. Pinheiro, H.A. Grundling, H.L. Hey, and J.R. Pinheiro, "Analysis and comparison of hybrid multilevel voltage source inverters," in Proc. IEEE 33rd Annu. Power Electron. Spec. Conf., Queensland, Australia, 2002, vol.2, pp.491-504.
[4]. M.A. Perez, P. Cortes, and J. Rodriguez, "Predictive control algorithm technique for multilevel asymmetric cascaded H-bridge inverters," IEEE trans. Ind. Electron., vol.55, no. 12,pp. 4354-4361, Dec.2008.
[5]. S.Manguelle, S.Manguelle, S.Mariethoz, M.Veenstra, and A.Rufer, "A generalized design principle of a uniform step asymmetrical multilevel converter for high power conversion," in Proc. EPE, Graz, Austria,2001,pp.1-12.

Paper Type	::	Review Paper
Title	::	Three Level Three Phase Cascade Dual-Buck Inverter With Unified Pulsewidth Modulation
Country	::	India
Authors	::	Aswathi M.||, S.Anusha
Page No.	::	38-43
	::	10.9790/3021-03713843
		0.4/3021-03713843
		3021-0307-0143

This paper presents a three phase voltage source dual buck inverter using unified PWM technique. This technique enhances the system reliability. It is a hard switching voltage source inverter. This topology uses power MOSFET as the active device and as a result it has lower switching losses and it can be designed at higher switching frequencies to reduce current ripple and size of passive components. The unified PWM technique reduces the computational burden in real time implementations by making use of a digital signal processor. Different PWM methods like Sinusoidal PWM, Space Vector PWM and Discontinuous Space Vector PWM (DSVPWM) can be applied to a three phase dual buck inverter. It does not need dead time and has no shoot through concerns. A three level cascaded dual buck inverter is also controlled using unified PWM technique.

[1]. S-Y. Park, P.W.Sun, W.Yu and J-S. Lai, "Performance evaluation of high voltage super junction MOSFETs for zero-voltage soft switching inverter applications," in Proc. 25th IEEE Appl. Power Electron. Conf.Expo.,Feb.2010,pp.387-392.
[2]. L. Saro, K. Dierberger and R.Redl,"High-Voltage MOSFET behavior in soft-switching converters: Analysis and reliability improvements," in Proc. 20th IEEE Telecom. Energy Conf., 1998, pp.30-40.
[3]. X.D. Huang, H.J. Yu, J-s Lai, A.R. Hefner, and D.W. Berning, "Characterization of paralleled super junction MOSFET devices under hard and soft-switching conditions," in Proc. 32nd IEEE Power Electron. Spec. Conf., 2001, vol.4, pp.2145-2150.
[4]. C.M. Johnson and V.Pickert, "Three-phase soft-switching voltage source converters for motor drives. II. Fundamental limitations and critical assessment," IEE Proc. Electr. Power appl., vol.146, no.2, pp.155-162, Mar.1999.
[5]. V.Pickert and C.M. Johnson, "Three-phase soft-switching voltage source converters for motor drives.I. Overview and analysis," IEE Proc. Electr. Power Appl.,vol. 146, no.2,pp.147-154,Mar. 1999.

Paper Type	::	Research Paper
Title	::	"A Comparative Study of Nurses Attitude Towards Criminal Psychiatric Patients"
Country	::	India
Authors	::	Shylaja Krupanidhi || Dr.H.M.Gangadharaiah
Page No.	::	44-46
	::	10.9790/3021-03714446
		0.4/3021-03714446
		3021-0307-0146

The study was conducted to assess the attitude of nurses towards criminal psychiatric patients. The comparison was between the nurses who have not given care to criminal psychiatric patients (Group I) and nurses who have given care to criminal psychiatric patients(Group II) working in NIMHANS Bangalore. A questionnaire was used to elicit the socio-demographic back ground of nurses. To assess their attitude, a semi structure attitude scale consisting of 52 items under 3 sub-scales "Criminal psychiatric patients in general‟, Nursing care‟ and "physical, psycho-social and rehabilitative interventions‟ were used. This was a 4 point likert type scale. Further, to explore the nursing care activities an open-ended questionnaire with 18 questions was administered to the nurses who have given care to criminal psychiatric patients. Results indicated that nurses who have given care to criminal psychiatric patients have better attitude than those nurses who have not given care to criminal psychiatric patients, both on the score of the sub-scale as well as the total attitude score. The result also show that nurses who are more than 40 years, head nurses and Christian nurses who have given care to Criminal Psychiatric patients have better attitude than the nurses who are less than 40 years of age, staff nurses and Hindu nurses of the same group respectively. The findings of this study have implications in understanding the nature of attitude of nurses towards Criminal Psychiatric patients and in planning appropriate intervention strategies.

[1]. Angira K K(1991) "Effect of sex of transgressor on the juridic judgment of male and female simulated jurors" psychosocial lingua, vol, 21(2), 79-84.
[2]. Banister, Peter Pordham Sara (1994). "Public Perception of crime seriousness" Issues in Criminological and Legal Psychology, No 24, 4-10.
[3]. Barber Bob (1985). "A chance of Security". Nursing Times, 28. 27-28
[4]. Caplon; Carol A (1993) "Nursing Staff and patient perception of the Ward Atmosphere in a Maximum Security Forensic Hospital ". Archives of psychiatric Nursing. Feb, Vol. 7(1), 23-29.
[5]. Carrol Jim (1995). "Attitude of Prison Nurse officers to drug Miss users". Nursing Times. April 12, Vol. 91, No. 15, 36-37.

Paper Type	::	Research Paper
Title	::	The Development of Time-Series Based Outage Distribution Models For Feeder Lines In South Western Nigeria
Country	::	Nigeria
Authors	::	Megbowon, Israel Olu. || and Oyeyemi, G. M.
Page No.	::	47-54
	::	10.9790/3021-03714754
		0.4/3021-03714754
		3021-0307-0154

This paper reports the development of a Time-Series based outage forecast model on electrical power distribution feeder lines in the Molete District of the network of the Power Holding Company of Nigeria (PHCN) within the city of Ibadan in Nigeria. A five-year(1999-2003) monthly outage data (in hours per month) gathered on the feeder lines was analyzed with the Time-series analysis program in the statistical software package Systat to generate the autocorrelation and the model parameters. These parameters are: smoothing coefficient, Trend coefficient, seasonality index and standard error of the forecast. The models were developed using the parameters. The models were then used to obtain a 24-month outage forecast figures and plots for each of the ten feeder lines. The results indicate that seasonal factors influenced the monthly outage on the feeder lines with the forecast figures rising to their peaks within the rainny season months of June to August while the minimum forecast figures occur during the dry season period which is from November to February on each feeder line. The outage hours on the feeder lines increased with the lengths of the lines with the outage forecast figures rising to as much as 392 hours per month and 328 hours per month respectively on CRIN and Ring-Road, the two longest feeder lines, in the rain season while they were as low as 51.6 hours per month and 64.77 hours per month respectively on Black-House and Best-Oil, the two shortest feeder lines within the same period.

 

Key Words: - Distribution feeder lines, time-series, autocorrelation plots, autoregressive moving average (ARMA), model parameters, monthly outage forecast models.

[1]. Adejumobi, I.A. (2005): An Assessment of Distribution System Reliability Using Time-Series, International Journal of Engineering and Engineering Technology Vol.4, No 1, pp. 1 – 9.
[2]. Box, G. E. P. and Jenkins, G. M (1969) Time-Series Analysis forecasting and control, Revised Edition, Holden - Day Publishers.
[3]. Mabert, V.A (1978) An introduction to short term forecasting using the Box-Jenkins methodology. . Production Planning and Control Division, American Institute of Industrial Engineers, Inc. Publication No 2 in the Monograph series.
[4]. Megbowon, I.O.(2009) A Reliability Assessment of the Transmission and Distribution Systems of the Electrical Power System in Southwestern Nigeria. Ph.D Thesis, School of Postgraduate Studies, Federal University of Technology, Akure, Nigeria.
[5]. NCC (2005) Generation And Transmission Grid Operations. 2005 Annual Technical Report.of the National Control Center of the Power Holding Company of Nigeria.(PHCN).