Synthesis and Structural Analysis of Nanocrystalline MnFe2O4

AbstractNanocrystalline form of manganese ferrite (MnFe2O4) has been synthesized by simple sol-gel auto combustion method using citric acid as chelating agent. The obtained nanocrystalline powders of manganese ferrite were subjected to structural and magnetic measurements. Temperature dependent magnetization was also carried out for the single phase nanocrystalline manganese ferrite and the results have been discussed in detail

The existence of inflection points for generalized log-aesthetic curves satisfying G1 data

Log-Aesthetic (LA) curves have been implemented in a CAD/CAM system for various design feats.LA curves possess linear Logarithmic Curvature Graph (LCG) with gradient (shape parameter) denoted as α.In 2009, a generalized form of LA curves called Generalized Log-Aesthetic Curves (GLAC) has been proposed which has an extra shape parameter as ν compared to LA curves.Recently, G1 continuous GLAC algorithm has been proposed which utilizes the extra shape parameter using four control points.This paper discusses on the existence of inflection points in a GLAC segment satisfying G1 Hermite data and the effect of inflection point on convex hull property.It is found that the existence of inflection point can be avoided by manipulating the value of α.Numerical experiments show that the increase of α may remove the inflection point (if any) in a GLAC segment

Stock assessment of mackerel in the Indian seas

Along both the coasts they start appearing in the catches when they are about two months old. But, along the west coast they are fiilly recruited to the fishery at an age of 6 months and along the east coast this happens at an age of 9 months. Bulk of the catches from west coast is by large seines of small meshes where young ones are liable to be caught and peak catches are from the size group of 140-149 mm. The major gear along the east coast is gill net with larger mesh and peak catches are from size group 190-199 mm. Along the west coast the estimated annual total mortality is 3.6. With an estimated M of 2.64 the fishing mortality F is 0.96 at an exploitation rate of 0.27 and E _^ estimated is 0.70

Ultrasonography and color Doppler in juvenile idiopathic arthritis: diagnosis and follow-up of ultrasound-guided steroid injection in the wrist region. A descriptive interventional study

<p>Abstract</p> <p>Background</p> <p>The wrist region is one of the most complex joints of the human body. It is prone to deformity and functional impairment in juvenile idiopathic arthritis (JIA), and is difficult to examine clinically. The aim of this study was to evaluate the role of ultrasonography (US) with Doppler in diagnosis of synovitis, guidance of steroid injections, and follow-up examinations of the wrist in JIA.</p> <p>Methods</p> <p>In 11 patients (median age 12.5 years, range 2-16), 15 wrists with clinically active arthritis were assessed clinically by US and color Doppler (Logiq 9, GE, 16-4 MHz linear transducer) prior to and 1 and 4 weeks after US-guided steroid injection.</p> <p>Results</p> <p>US detected synovitis in the radio-carpal joints, the midcarpal joints, and the tendon sheaths in 87%, 53% and 33% of the wrists, respectively. Multiple compartments were involved in 67%. US-guidance allowed accurate placement of steroid in all 21 injected compartments, with a low rate of subcutaneous atrophy. Synovial hypertrophy was normalized in 86% of the wrists, hyperemia in 91%, and clinically active arthritis in 80%.</p> <p>Conclusions</p> <p>US enabled detection of synovial inflammation in compartments that are difficult to evaluate clinically and exact guidance of injections, and it was valuable for follow-up examinations. Normalization of synovitis was achieved in most cases, which supports the notion that US is an important tool in management of wrist involvement in JIA.</p

Ultrasonography and color Doppler in juvenile idiopathic arthritis: diagnosis and follow-up of ultrasound-guided steroid injection in the ankle region. A descriptive interventional study

BACKGROUND: The ankle region is frequently involved in juvenile idiopathic arthritis (JIA) but difficult to examine clinically due to its anatomical complexity. The aim of the study was to evaluate the role of ultrasonography (US) of the ankle and midfoot (ankle region) in JIA. Doppler-US detected synovial hypertrophy, effusion and hyperemia and US was used for guidance of steroid injection and to assess treatment efficacy. METHODS: Forty swollen ankles regions were studied in 30 patients (median age 6.5 years, range 1-16 years) with JIA. All patients were assessed clinically, by US (synovial hypertrophy, effusion) and by color Doppler (synovial hyperemia) before and 4 weeks after US-guided steroid injection. RESULTS: US detected 121 compartments with active disease (joints, tendon sheaths and 1 ganglion cyst). Multiple compartments were involved in 80% of the ankle regions. The talo-crural joint, posterior subtalar joint, midfoot joints and tendon sheaths were affected in 78%, 65%, 30% and 55% respectively. Fifty active tendon sheaths were detected, and multiple tendons were involved in 12 of the ankles. US-guidance allowed accurate placement of the corticosteroid in all 85 injected compartments, with a low rate of subcutaneous atrophy (4,7%). Normalization or regression of synovial hypertrophy was obtained in 89%, and normalization of synovial hyperemia in 89%. Clinical resolution of active arthritis was noted in 72% of the ankles. CONCLUSIONS: US enabled exact anatomical location of synovial inflammation in the ankle region of JIA patients. The talo-crural joint was not always involved. Disease was frequently found in compartments difficult to evaluate clinically. US enabled exact guidance of steroid injections, gave a low rate of subcutaneous atrophy and was proved valuable for follow-up examinations. Normalization or regression of synovial hypertrophy and hyperemia was achieved in most cases, which supports the notion that US is an important tool in the management of ankle involvement in JIA

Stress analysis of axial flow cooling fans

Tests on automobile radiator cooling fans of three types of construction pressed out from sheets are reported. The blades of the fans are treated as twisted (from tip to root) cantilever beams (fixed at root) for the purpose of analysis. The effects of centrifugal force, driving torque, and the axial thrust over the blade due to air flow are taken into account. Air flow measurements are obtained using a pitot-static probe. The input power for various speeds is also recorded. The stress values are verified with the strain gauge readings taken at the root and at mid span. The effects of twist angle and number of blades are also discussed. The study does not include riveted construction

ENERGY OPTIMIZATION IN CLUSTER BASED WIRELESS SENSOR NETWORKS

Wireless sensor networks (WSN) are made up of sensor nodes which are usually battery-operated devices, and hence energy saving of sensor nodes is a major design issue. To prolong the networks lifetime, minimization of energy consumption should be implemented at all layers of the network protocol stack starting from the physical to the application layer including cross-layer optimization. Optimizing energy consumption is the main concern for designing and planning the operation of the WSN. Clustering technique is one of the methods utilized to extend lifetime of the network by applying data aggregation and balancing energy consumption among sensor nodes of the network. This paper proposed new version of Low Energy Adaptive Clustering Hierarchy (LEACH), protocols called Advanced Optimized Low Energy Adaptive Clustering Hierarchy (AOLEACH), Optimal Deterministic Low Energy Adaptive Clustering Hierarchy (ODLEACH), and Varying Probability Distance Low Energy Adaptive Clustering Hierarchy (VPDL) combination with Shuffled Frog Leap Algorithm (SFLA) that enables selecting best optimal adaptive cluster heads using improved threshold energy distribution compared to LEACH protocol and rotating cluster head position for uniform energy dissipation based on energy levels. The proposed algorithm optimizing the life time of the network by increasing the first node death (FND) time and number of alive nodes, thereby increasing the life time of the network

Experience in Long Term Operation of Sodium Loop for Creep Experiments in Dynamic Sodium at High Temperature

AbstractThe Creep loop of In-Sodium Test Facility (INSOT) has been operated for conducting four creep experiments in dynamic sodium simultaneously at high temperature of 873K on SS316L(N) base metal at two different stress levels of 215MPa and 225MPa with the test durations of 7160, 7810, 8800 and 9612hours. The creep experiment with duration of 9612hours at 873K is the longest test campaign in the creep loop history. This was made possible by adopting several pre- checks, conducting periodic loop surveillance and implementing a few innovative solutions to ensure the safe, trouble free, uninterrupted loop operation. The sodium system as well as test parameters were closely monitored by PLC/PC SCADA control system and maintained for the in-sodium creep experiments. The purity of sodium was monitored periodically by plugging meter and maintained by continuous on line operation of cold trap. Oxygen level in sodium was maintai ed less than 2ppm. The temperature of sodium was maintained at 873K±1K during the experiments. The sodium velocity surrounding the test specimen was maintained at 2.5 ms-1 in the test chambers. Sodium sampling was done to assess the impurity content in the loop and carbon activity assessment was conducted by nickel foil equilibration method. This paper presents measures adopted and the experience gained for successfully conducting the creep experiments in dynamic sodium at high temperature for very long duration