IOSR-JAP   Volume-6 ~ Issue-2 ~ March-April 2014

ABSTRACT: In the present paper, we have been studied the theoretical transition pressure of samarium chalcogenides by using potential model. We have reviewed bulk modulus by simple calculation. The transition pressure, volume collapse and bulk modulus predicted from this approach are found to be close to experimental data.

Key words: Samarium Chalcogenides, phase transition, transition pressure.

[1] A. Jayaraman, V. Narayanamurti, E. Bucher, and R. G. Mines, Phys. Rev. Letters1 25, 1430 (1970).
[2] R. Kitagawa, H. Takeba, and K. Mornaga, Appl. Phys. Letters 82, 3641 (2003).
[3] E. Rogars, P. F. Smell, P. Dorenbos, and E. V. D. Kolk, J. Phys. Condensed Matter 22, 015005 (2010).
[4] K. H. J. Buschow, Concise Encyclopedia of Magnetic and Supercondiuncting Material (2005), p. 318.
[5] C. M. Verma and V. Heine, Phys. Rev. 11, 4763 (1975).
[6] D. Varsney, R. Kinge, P. Sharma, N. Kaurav, and R. K. Singh, Indian J. Phys. 43, 939 (2005).

ABSTRACT: A potential model is develop for determining the transition pressure of samarium chalcogenides (SmX,X= S,Se and Te).This methods requires only two free parameters namely range and hardness (  and b ) to calculate the transition pressure and volume collapse with different combination. It also provides the information on the structural changes Nacl- to CsCl.

Key words: Samarium Chalcogenides, phase transition, transition pressure.

[1] A. Jayaraman, V. Narayanamurti, E. Bucher, and R. G. Mines, Phys. Rev. Letters1 25, 1430 (1970).
[2] R. Kitagawa, H. Takeba, and K. Mornaga, Appl. Phys. Letters 82, 3641 (2003).
[3] E. Rogars, P. F. Smell, P. Dorenbos, and E. V. D. Kolk, J. Phys. Condensed Matter 22, 015005 (2010).
[4] K. H. J. Buschow, Concise Encyclopedia of Magnetic and Supercondiuncting Material (2005), p. 318.
[5] C. M. Verma and V. Heine, Phys. Rev. 11, 4763 (1975).
[6] D. Varsney, R. Kinge, P. Sharma, N. Kaurav, and R. K. Singh, Indian J. Phys. 43, 939 (2005).
[7] M. P. Tosi and F. G. Fumi, J. Phys. Chem. Solids 23, 359 (1962).
[8] M. L. Huggins and J. E. Mayer, J. Chem. Solids 3, 637 (1935).

ABSTRACT: The need for effective and efficient telephone billing system in Nigerian telecommunication industries is increasing everyday as a result of the match towards technological advancement. As such, this study tried to investigate the existing telephone billing system used in the various telecommunication industries in Nigeria with a view to improving on them. To accomplish this, the researcher developed comparative analysis for five telecommunication industries in Nigeria. Etisalat Network was chosen as a case study because it is the network that has the best quality of service and has lowest customer tariff with an effective and responsive customer care unit. Interestingly, the billing system of Etisalat network was discovered to have some shortcomings such as customer name, town name and town code. All these parameters are not displayed in the bill after calls. This research has therefore made an attempt to incorporate the three parameters which did not exist in the Etisalat call summary receipt. This task was achieved using Software Engineering Approach and the Program Source Code was developed using Turbo Pascal version 6.0.

Keywords: Billing, Customer friendly, Effective call summary, Parameter, Service quality.

[1] A.T Bell, Telecommunications billing, A Journal on Telecom billing 2005 pg1-30.
[2] NCC Press Release, (2011). "Quarterly Summary of Telephone Subscribers in Nigeria, (internet) (http://www. ncc.gov.ng) 24th April, 2011.
[3] NCC Press Release, (2007). "Quarterly Summary of Telephone Subscribers in Nigeria, (internet) (http://www. ncc.gov.ng) 19th September, 2011.
[4] Etisalat Nigeria Plc official website http:// www.etisalatnigeria.com Quelch and Hoff, Customizing Global Marketing Harvard Business Review 2006 64, 59-68.
[5] Omotayo and Joachim, Customer Service in the Retention of Mobile Phone Users in Nigeria
[6] African Journal of Business Management 2008 Vol.2(2), pp 026-031, February 2008, ISSN 1993 – 8233.
[7] Babalola and Adegoke, Quality of Service Analysis of GSM Telephone System in Nigeria
[8] American Journal of Scientific and Industrial Research, 2011.

ABSTRACT: The hardness of the crystals was determined by Vicker's Hardness test. The energy band gaps were also reported for each crystal. These crystals have been characterized by optical and mechanical studies. The decomposition temperatures and weight loss have been estimated from the Thermo Gravimetric Analysis and Differential Thermal Analysis and hardness was found from the Vicker's microhardness measurement. In the present work, pure crystals of L–Alanine, HCl, KCl and KDP mixed L Alanine crystals have been grown by slow evaporation method.

Key words: Vicker's microhardness,bandgap, Thermal analysis,alanine,etc.,

[1] Gilman, J.J Ed., (1963), "The Art and Science of growing Crystals", John Wiley & Sons, Inc, New York, London.
[2] Kittel, C. (1977), "Introduction to Solid State Physics", Wiley Eastern Limited, New Delhi.
[3] Brice, J.C (1965), "Crystal Growth Processes", John Wiley & sons, New York.
[4] Brice, J.C (1965), "The growth of crystals from the Melt", (North Publishing Company, Amsterdam.
[5] Ramasamy, P., C. Subramaniam and R. Dhanasekaran (1986), "Proceedings of UGC summer school on crystal growth and characterization of Advanced Materials for solid state applications".