Noise (AWGN) Avoidance in CDMA Systems Using the Mechanism of Spread Spectrum

In today communication systems the most probable problems are that of channel capacity, jamming and interference or noise. The channel capacity can be maximized by multiplexing the channel. While the jamming problem and for noise reduction the most important technique that we can apply is spread spectrum. That by spreading the spectrum of the original message signal, the impact of noise upon the message signal can be reduced. For that purpose, two different techniques that is DSSS(Direct Sequence Spread Spectrum) and FHSS (Frequency Hoping Spread Spectrum) can be applied. Since the two approaches are core ideas upon which CDMA system is based, so in this paper we have analyzed both the techniques to observe that h up to what extent they are efficacious in removing AWGN in CDMA systems communication. IndexTerms:DSSS, FHSS, Code Division Multiple Access (CDMA), Additive White Gaussian Noise (AWGN), spread spectrum

Integration of surfactants and time release nutrients with pneumatic fracturing process

The objective of this laboratory study was the development of two novel improvements to the pneumatic fracturing process which would extend its present application. The first involved use of surfactant during pneumatic injection, and the second was subsurface injection of time-release dry nutrient pellets for enhancement of in situ biodegradation. Bench scale tests demonstrated that pneumatic fracturing can be successfully performed with air containing a surfactant solution (foam fracturing). The results showed that foam fracturing followed by increased the rate of surrogate contaminant removal from 8% to 10% compared with regular pneumatic fracturing. These increases were attributed to enlarged fracture networks and increased airflow. Commercially available anionic surfactants, which are biodegradable, were used for the process. Recommendations for field scale applications were also developed. It was also shown that injection of time release nutrient pellets into subsoil during pneumatic fracturing is feasible. Bench scale equipment for this process was developed and tested. Mechanical damage of the nutrient pellets during pneumatic injection was evaluated by different methods, and it was determined that serious damage was sustained above 75 psi. These results suggest pellets with higher mechanical strength characteristics are necessary for successful field integration with pneumatic fracturing process

Occupational Health and Safety (OHAS) crisis in tanneries of Bangladesh: Is this the violation of labor rights?

Tannery business in Bangladesh is one of the oldest manufacturing sub-sectors and it has huge growth potential. It has been remained profitable venture since its inception. However, this sector has got adverse affect both in human life and environment. Employees who work for tanneries face severe health hazards and people live in neighborhood are also affected by environmental pollutions. Toxic exposure of chemicals in tanneries of Bangladesh violates health and safety compliances. Both workers and neighborhood people of tanneries suffer from gastrointestinal, respiratory, jaundice, hypertension and skin diseases due to inefficient and improper waste management system. Tanneries in Bangladesh have failed to maintain Occupational Health and Safety (OHAS) which is also the violation of labor right. This may lead to labor unrest in near future like RMG sector in Bangladesh. This study explores the current health and safety practices at tanneries in Bangladesh. Health problems and challenges of tannery workers are also reported in this research, and some recommendations are made at the end as possible remedy. Key Words: Tannery, Occupational Health and Safety (OHAS), Labor Right & Unrest

Increasing employee job satisfaction as well as organizational performance through effective HRM practices in private commercial banking sector of Bangladesh.

Private commercial banking sector in Bangladesh is booming in recent times with higher number of potential customers from the local market due to rapid industrialization. New private commercial banks are also opening in every five year times.  But this sector is facing challenges in achieving management efficiency one of which leads to experience high level of competition. In order to achieve sustainable growth in this competitive market, and to achieve higher organizational performance, special emphasis should be given to improve HRM practices in this sector. The relationships among HRM practices, Job satisfaction and business performance have been an integrated issue for business and operational environment. HRM practices are also considered as major contributory factor for higher organizational performance through higher job satisfaction. This study has been conducted to explore the influence of HRM practices on job satisfaction and how job satisfaction brings higher organizational performance. Since, the HRM practices are mostly responsible for the achievements of business strategy and success; particular attention has given in this paper to focus the importance of HRM practices. Key Words: HRM Practices, Job Satisfaction, Organizational Performance, Private Commercial Bank

Study of Mechanical Properties of Glass Fiber and Flyash Particulate Reinforced Al 2219 Hybrid Composites

Composite material is a material composed of two or more distinct phases (matrix phase and reinforcing phase) and having bulk properties significantly different from those of any of the constituents. Many of common materials (metals, alloys, doped ceramics and polymers mixed with additives) also have a small amount of dispersed phases in their structures, however they are not considered as composite materials since their properties are similar to those of their base constituents (physical property of steel are similar to those of pure iron). Favorable properties of composites materials are high stiffness and high strength, low density, high temperature stability, high electrical and thermal conductivity, adjustable coefficient of thermal expansion, corrosion resistance, improved wear resistance et