Proposed Scheme for Secured Routing in MANET

A Mobile Adhoc Network (MANET) is characterized by mobile nodes, multihop wireless connectivity, infrastructure less environment and dynamic topology. A recent trend in Ad Hoc network routing is the reactive on-demand philosophy where routes are established only when required. Stable Routing, Security and Power efficiency are the major concerns in this field. This paper is an effort to study security problems associated with MANETS and solutions to achieve more reliable routing. The ad hoc environment is accessible to both legitimate network users and Malicious attackers. The study will help in making protocol more robust against attacks to achieve stable routing in routing protocols

Direct Simulation of Flow over A Wall-Mounted Hump

Simulating separated flows at high Reynolds numbers using Reynolds Averaged Navier-Stokes (RANS) modeled equations remains a challenge in aeronautics. The main hindrance to progress stems from the lack of extended de- tailed data pertinent to the root cause of failure of RANS models, as well as the little progress in RANS modeling innovations in the past several decades. The goal of the current effort is to generate data for separated flow at a Reynolds numbers where conventional models are challenged. We use Direct Numerical Simulations to model turbulent flow over the wall-mounted hump configuration to investigate the physics of flow separation and boundary layer recovery, as well as provide data relevant to the modeling community. A chord-based Reynolds number of Re(sub c) = 47,500 is considered with a turbulent inflow profile of Re(sub ) = 1,400 ( /c = 3%). We use FDL3DI, a code that solves the compressible Navier-Stokes equations using high-order compact-difference scheme and filter, with the standard re- cycling/rescaling method of generating turbulent boundary layers as inflow to the computational domain. Two differ- ent configurations of the upper-wall are analyzed for two sets of boundary conditions (slip and no-slip). The results are compared with the available higher Re(sub c) (= 936,000, Re(sub ) = 7,200, /c = 0.77%) experiment for major flow features. The simulated lower Rec allows for DNS-like mesh resolutions, and adequately wide spans. The results from these simulations show earlier separation and delayed reattachment compared to Re(sub c) = 936,000, and significantly higher skin friction in the forebody of the hump. We also find that the upper-wall shape and boundary condition influence pressure distribution over the hump, whereas skin friction is only influenced by the boundary condition

Implicit Large-Eddy Simulations of Zero-Pressure Gradient, Turbulent Boundary Layer

A set of direct simulations of zero-pressure gradient, turbulent boundary layer flows are conducted using various span widths (62-630 wall units), to document their influence on the generated turbulence. The FDL3DI code that solves compressible Navier-Stokes equations using high-order compact-difference scheme and filter, with the standard recycling/rescaling method of turbulence generation, is used. Results are analyzed at two different Re values (500 and 1,400), and compared with spectral DNS data. They show that a minimum span width is required for the mere initiation of numerical turbulence. Narrower domains ((is) less than 100 w.u.) result in relaminarization. Wider spans ((is) greater than 600 w.u.) are required for the turbulent statistics to match reference DNS. The upper-wall boundary condition for this setup spawns marginal deviations in the mean velocity and Reynolds stress profiles, particularly in the buffer region

Electrochemical studies on zirconium phosphoborate based heterogeneous membranes

Electrode potential measurements have been applied to study electrical characteristics like transport numbers, permselectivity & fixed charged density of zirconium phosphoborate ion exchange membranes. The potential measurements were made across the cation exchange membrane maintained at 27±0.1 °C, using halide and nitrate salts of alkali and alkaline earth metals as electrolytes. The membrane potentials, transport numbers and permselectivity values increase with increase in average concentration from 0.0055 M to 0.0495 M for 1:1 and 1:2 electrolytes. With the increase in concentration of the electrolyte, the number of counter ions interacting with the membrane surface increases leading to enhanced Donnan exclusion responsible for the increase of transport numbers. Fixed charge density of the membrane (X) for 1:2 electrolytes is higher in magnitude than for 1:1 electrolytes indicating that the cation exchange is taking place as hydrated species. This hypothesis is supported by higher transport numbers for alkaline earth metal ions than alkali metal ions throughout the range of concentration

Nutritional status of 1-5 years children in the urban slum area of Jagdalpur city, Bastar region, Chhattisgarh

Background: Nutritional status is the best indicator of the child health. Malnutrition has both short and long term adverse ramifications. As per NFHS III 47% children are stunted in the state of Chhattisgarh. However still many communities in the tribal dominated and naxal affected state may remain affected, hence the study was planned to identify the nutritional status of children and find out its determinant.Methods: Present cross-sectional study was conducted among 12-59 months children in the urban slum of Jagdalpur city, Bastar region of Chhattisgarh. Predesigned and pretested questionnaire was administered to the caregiver of the child, information on socio-demographic characteristics was obtained and anthropometric measurements were taken. Statistical Analysis: all frequencies were derived for completeness of data. WHO Anthro Software version 3.1.0 was used to classify the malnutrition status. Chi-square test was applied to find association between dependent variables.Results: Out of 225 children 53.3% were boys and 46.7% were girls. The overall prevalence of underweight stunting and wasting was 28.4%, 41.3%, and 19.1% respectively.Conclusions: Prevalence of underweight has reduced in the district over a period of years. However high level of stunting, a sign of chronic hunger points towards the pivotal role of socio-demographic and behavioral practices prevalent in the district. Interaction with health system in the form of ANC, institutional delivery and safeguarding effective 100% immunization coverage has shown preventive effect

Measurements and predictions of a liquid spray from an air-assist nozzle

Droplet size and gas velocity were measured in a water spray using a two-component Phase/Doppler Particle Analyzer. A complete set of measurements was obtained at axial locations from 5 to 50 cm downstream of the nozzle. The nozzle used was a simple axisymmetric air-assist nozzle. The sprays produced, using the atomizer, were extremely fine. Sauter mean diameters were less than 20 microns at all locations. Measurements were obtained for droplets ranging from 1 to 50 microns. The gas phase was seeded with micron sized droplets, and droplets having diameters of 1.4 microns and less were used to represent gas-phase properties. Measurements were compared with predictions from a multi-phase computer model. Initial conditions for the model were taken from measurements at 5 cm downstream. Predictions for both the gas phase and the droplets showed relatively good agreement with the measurements