Synthesis and Structural Characterization of Niobium Doped Lead-Telluride Glass-Ceramics

The basic glasses with composition (70-x) TeO2-30PbO-xNb2O5 (where x=0.1 mol % and 0.2 mol %) were prepared by melt quenching method and heat treated at 2800C for 30 min. The samples becoming glass ceramics was confirmed by SEM. The XRD parameters such as crystallite size of these glass ceramics decreases as increase the impurity and is the order of 184-109A0 . However, micro strain (ε) and dislocation density (δ) increases. Glass transition and thermal stability estimated from DSC measurements and it has been found that both increase with increasing of impurity. Infrared Absorption spectra were measured for TeO2 glass and glass ceramic doped with Nb2O5. The recorded bands attributed to the different modes of vibration and stretching of Te-O band. Optical Absorption spectra of TeO2-PbONb2O5 system shows that the absorption edge has a tail extending towards the lower energies and shifts towards for higher energies for rare earths-doped glass-ceramics. The degree of the edge shift was found to depend on the structural rearrangement and the relative concentrations of the glass basic units. The general appearance of the absorption spectra of these rare earth doped TeO2 glasses are similar to the spectra observed for other glasses doped with the same kind of rare earth oxides

THE CAMPUS SECURITY TRACKING SYSTEM BASED ON RFID AND ZIGBEE NETWORK

This paper contains the campus security tracking system (CST) has been designed and implemented using the RFID and ZigBee network. The CST reads the RFID tags data through FRID & ZigBee node, and then sends it to PC node by a custom wireless protocol on the ZigBee. PC node gives related warning (or) hints by the result of matching master slave RFID tag information. When the warning occurs, its user can logon the web system to get the real-time tracking for valuables with embedded slave RFID where the thief arrives at any one access control node, it would be blocked. User can also manage his own valuables such as lending and recovery operation through the Web manager center. The system can achieve large-scale logistics management and tracking, and has good market prospects and value in use

AN EXPERIMENTAL STUDY OF APPLYING VARIOUS CUTTING EDGES ON WIPER MILLING INSERTS IN FACE MILLING AISI 1070 STEEL

In metal cutting industry, edge preparation on carbide inserts have a significant effect on the productivity of a machine. In this study, the effect of various cutting edge preparations on wiper facet which influences various force components and surface finish in the rough milling operation of AISI 1070 steel were experimentally investigated. Tungsten Carbide inserts with three distinct edge preparations and AISI 1070 steel blocks were used. Three-factor (Cutting speed, Feed and Geometry), three-level full factorial design experiments were conducted under dry conditions. During the rough milling operation, three components of forces and surface finish of the machined surface were measured. This study shows that the effect of various edge geometries is more significant on surface finish and has very little impact on the force components

DRY SLIDING WEAR BEHAVIOR OF DIFFUSION BONDED AZ-91 MAGNESIUM ALLOY REINFORCED WITH SIC PARTICLES

Magnesium composites reinforced with 2, 4, 6 Wt.% of silicon carbide particles at different particle size of 10, 25 and 45 mm was synthesized using diffusion bonding process. Further the samples for scanning electron microscopic analysis and tribological analysis were made from the composites. Dry sliding wear test was carried out with L27 orthogonal design array on pin on disc tribometer. Mass loss of the pins was measured and wear rate was calculated. A statistical analysis was performed with the measured wear rate, the optimal parameter combination level was identified with main effect plot. From ANOVA analysis the significant parameters was identified

IN VITRO α-AMYLASE AND Α-GLUCOSIDASE INHIBITOR ACTIVITIES OF ALBIZIA PROCERA STEM BARK

Objective: This current study was carried out to determine the in vitro α-amylase and α-glucosidase inhibitory activity of extract and fractions of Albizia procera. Methods: The α-amylase and α-glucosidase inhibition assay was carried out at concentrations 50–2000 μg/ml and acarbose used as standard. The absorbance was measured at 540 nm and recorded by spectrophotometer. Percentage inhibition was calculated for both the assays. Preliminary phytochemical screening was also evaluated using standard procedures.Results: There was a dose-dependent percentage inhibition of extracts (petroleum ether and ethanol) and fractions (chloroform, ethyl acetate, and n-butanol). The ethanol extract and n-butanol fraction show good inhibitory activity against both α-amylase and α-glucosidase with the percentage inhibition of 86.20% and 88.20% and 83.13% and 87.10%, respectively. The preliminary phytochemical screening shows that ethanol extract consists of active constituents such as flavonoids and phenolic compounds and tannins.Conclusion: This finding suggests that the ethanol extract and n-butanol fraction show good inhibitory activity against both α-amylase and α-glucosidase and show good antidiabetic activity