Archives-J 

In this paper, we consider a new method to improve the performance of TCP over wireless networks. The method employs NDG loss-predictor function to determine congestion losses from that of transmission loss. The sender window can adjust its size depending on the loss information. If the loss is due to congestion congestion control algorithm is invoked to decrease the flow rate. If the loss is due to wireless transmission, immediate-recovery algorithm is invoked to recover the losses caused by the sender TCP. To minimise the packet losses due to congestion, we use stability analysis over the system by applying a time-delay control theory. By constructing Hermit matrix, system analysis is made for asymptotic stability. Explicit conditions are derived for Pmax (RED controller) and ? (fNDG parameter) in terms of wireless network parameters. Using the characteristic equation of the Hermite matrix, convergence analysis of the instantaneous queue length at the bottleneck router is made. Convergence of the queue length to a given target value is analysed. This minimise the oscillatory behaviour of the RED router. An approximate solution of queue length is also derived. Our results provide better solutions for global stability and convergence conditions of the wireless system.

35 female weanling rabbit of an average weight of 510g were used in a feeding trial that lasted 12 weeks to evaluate the effect of inclusion of different levels of REE (0, 100, 200, 300 and 400ppm) on the performance, blood and serum parameters of the animals. The animals were randomly allotted to five treatments of 7 replicates (1 animal per replicate) per treatment. The initial weight, final weight and fed intake were monitored, recorded and analysed. Blood samples was collected and used for the haematological analysis. There was significant (p>0.05) difference in the final weight, daily weight gain, daily feed intake and feed conversion ratio. However, the daily weight gain and feed conversion ratio increases as the inclusion level of dietary REE increase likewise the. Haemoglobin (Hb), Packed cell volume (PCV), Red blood cell (RBC), White blood cell (WBC), neutrophils, eosinophils and lympocytes were not significantly (p>0.05) influenced among the dietary treatment. The total protein, albumin, globulin, cholesterol and urea were also not significantly (p>0.05) different, though all higher numerically in supplemented diets compared to the control.

Network Interface Module (NIM) is a front-end receiver block, which interfaces incoming signals from outside world in to the High Definition (HD) Radio Frequency (RF) receivers. In most of the cases, NIM receives only one type of signal and down converts RF in to Intermediate Frequency (IF). In modern receivers there could be a separate block for this signal interface or there could be single silicon which acts as network interface module, Tuner and demodulator. Introduction of modularity concept in the front-end block of receivers will helps to enhance the performance of the receivers as and when required.

The concept of the low heat rejection (LHR) is to suppress the heat rejection to the coolant and recovering this heat energy into useful work. The main objective of this work is to increase the performance of the engine and improve the fuel economy by coating piston face using metal matrix composite materials (MMCM). The neem kernel oil is selected as fuel, which has high viscosity, low volatility and low cetane number. In the present study, neem kernel oil (NKO) is converted into neem kernel oil methyl esters (NKOME) by transesterification process. The tests are conducted with NKO, NKOME and diesel on the coated and uncoated engines for different loads at rated speed. The combustion, emission and performance characteristics are determined and compared.

The growing concern due to environmental pollution caused by the conventional fossil fuels and the realization that they are non-renewable have led to search for more environment friendly and renewable fuels. Among various options investigated for diesel fuel, biodiesel obtained from vegetable oils has been recognized world over as one of the strong contenders for reductions in exhaust emissions. In this present experimental work is carried out the performance and emission characteristics of diesel and biodiesel (Mahua) is analyzed. The results of depicts B20 Mahua blend of biodiesel is having the better characteristics in terms of performance and emission.

The present study attempts to know the level of preference towards values between male and female students of different B.Ed. College in Tamil Nadu. The investigator has employed the survey method for collecting the data by using the well-designed and validated research tools for primary data collection. The tools have been administered to a random sample of 900 B.Ed college students in Tamil Nadu. The main objectives of the study is to find out the preference on values such as, economic, political, theoretical, social, religious and aesthetical values. The result reveals that the economical and political values are correlating with gender. The researcher has offered suitable suggestions to the stakeholders and policy makers pertinent to the findings of the study

SQL injection attacks on the web databases are mainly due to the application development process where the coding process is vulnerable as it was not secured. This however can be prevented by various methods. One of the techniques is to limit the access of database to authorized users only. Database contents are encrypted so as to allow a secure way of efficient query processing directly on the encrypted database. SQL attacks can be prevented through highly secure authentication schemes in the login phase itself. In this paper, we have presented one such technique. Our scheme proposes that access be provided to verified users only. That is, at the time of creation of the user account, a user key is generated for every user where the user name and password at the time of login is encrypted by Blowfish encryption and RSA technique at different levels of the total encryption process. The access is provided by the server after confirming the user’s authenticity. On server side the encrypted data will be decrypted using the user key. The decrypted data will be checked and if the user is genuine, further access will be granted to the database. The RSA encryption will work as a protective cover for the SQL query generated by the user at the client’s end.

The effect of novel corrosion inhibitors, new class of substituted benzotriazoles namely N-[(benzylidene hydrazino)-propyl]- benzotriazole(BPBT) and N-[(4-oxo-2-phenyl-1,3-thiazolidineimino)-propyl]-benzotriazole (OPBT) were synthesised and their inhibition behaviour on Cu-Ni alloy in natural sea water were investigated by the weight-loss method, potentiodynamic polarisation and electrochemical impedance studies. Polarization measurements showed that the organic compounds investigated are mixed type inhibitors, inhibiting the corrosion of Cu-Ni alloy by blocking the active sites of the metal surface. They decrease the anodic reaction rate more strongly than the cathodic reaction rate and render the open circuit potential of Cu-Ni alloy more positive in natural sea water. Changes in the impedance parameters (charge transfer resistance (Rct) and double layer capacitance (Cdl)) are related to adsorption of organic inhibitors on the metal surface, leading to the formation of a protective film. Solution analysis revealed the decrease in dissolution of both copper and nickel in the presence of benzotriazole derivatives. The morphology of the Cu-Ni alloy after corrosion in the presence and absence of the benzotriazole derivatives was examined using scanning electron microscopy (SEM). All studies clearly show that the substituted benzotriazoles inhibits the corrosion of Cu-Ni alloy in natural seawater and the value of inhibition efficiency increases with increasing concentration of inhibitors.

The study was retrospective and cross-sectional study where hospital records were accessed to establish patient-nurse ratio in relation to deliveries conducted monthly between 2011 and 2015 to establish staff workload. 167 nurses were engaged with the aim of determining psychosocial risk factors, prevalence and effects on maternal care outcomes at selected level 4 and 5 private and government health facilities in Mombasa County through a modified Copenhagen Psychosocial questionnaire. Cluster sampling was used to pick hospitals on the basis of levels; stratified sampling to identify the respondents; and systematic sampling to determine every Kth staff involved in the study. Data analysis was done using SPSS package, whose findings indicate that patient/nurse ratio was higher in Government Hospitals compared to private hospitals accounting for approximately 1:4 and 1:3 respectively. Generally, majority of the respondents had a positive perception about their work environment despite 66.9% perceiving to a large extent that their work was emotionally demanding, 80.9% their work exposed them to undue pressure/demands from their patients and relatives and only 58.6% felt somewhat or to a small extent motivated and involved. Due to this perception about current work environment, 70% of the respondents considered looking for work elsewhere with only 22.9% willing to remain working in their respective work places. Further analysis indicated that work environment influenced by 65.8% the decision to change jobs due to lack of motivation and failure to involve them in decision making. This perception, however, differed across private and GoK hospitals, male and female, and across the different age brackets.

The present article described the design technique of hardware electronic circuit based on modified Rossler equations. The dynamical behaviour of the proposed system has been studied by computer simulation and in electronic experiment. The results of periodic and chaotic behaviour of the hardware circuit are reported. Next the synchronization between two such electronic circuits is experimentally verified and a secure scheme of communication is described using chaos masking technique. The hardware experimental results are incorporated in this article to support the design algorithm.