Performance analysis of tool electrode prepared through laser sintering process during electrical discharge machining of titanium

The International Journal of Advanced Manufacturing Technology - It is of great significance for intelligent manufacturing to study condition monitoring and diagnosis methods to realize early...     

Factors affecting air sparging remediation systems using field data and numerical simulations

Field data from five air sparging sites were used to assess the effect of several soil, contaminant, and air sparging system factors on the removal time and associated costs required to reach specified clean-up criteria. Numerical simulations were also performed to better assess the field data and to expand the data sets beyond the five field sites. Ten factors were selected and evaluated individually over a range of values based on information from practitioners and the literature. Trends in removal time and removal cost to reach a specified clean-up criterion were analyzed to ascertain the conditions controlling contaminant removal with variations in each factors' value. A linear sensitivity equation was used to quantify system dynamics controlling the observed contaminant removal trends for each factor. Factors found most critical across all field sites in terms of removal time and/or cost were contaminant type, sparge pulsing schedule, number of wells, maximum biodecay rate, total soil porosity, and aquifer organic carbon content. Factors showing moderate to low effect included the depth of the sparge point below the water table, air injection rate/pressure, horizontal air conductivity, and anisotropy ratio. At each field site, subsurface coverage of sparged air, sparged air residence time, contaminant equilibrium in the system, contaminant phase distribution, oxygen availability to microbes, and contaminant volatility seem to control the system responses and were affected by one or more of the 10 factors evaluated.     

Inactivation of Escherichia coli K12 by pulsed UV light on goat meat and beef: microbial responses and modelling

The objective of this study was to investigate the efficacy of pulsed UV light (PUVL) in inactivating Escherichia coli K12 on goat meat and beef surfaces. Inactivation studies were conducted for 5 to 60 s at three distances from the light source (4.47, 8.28 and 12.09 cm) in the PUVL chamber. Predictive models using regression and artificial neural networks (ANN) were developed to quantify log reductions. Pulsed UV light was more effective on beef than goat meat. Maximum log reductions of 1.66 and 1.74 CFU mL⁻¹ rinse solution were achieved on goat meat and beef, respectively, at 4.47 cm distance for 60 s. Escherichia coli K12 reduction increased significantly with increasing treatment time and closer distance from the light source. In general, both ANN and regression models effectively described inactivation of E. coli K12. Predictive models describing PUVL inactivation kinetics of E. coli K12 can be used for process optimisation in meat industry.     

On the generation and recovery of hot carrier induced interface traps: a critical examination of the 2-D R-D model

The generation and recovery of interface traps (N/sub IT/) during and after hot carrier injection stress is evaluated by the recently proposed two-dimensional (2-D) reaction diffusion (R-D) model. The power law time exponent (n) of N/sub IT/ generation as well as the magnitude of fractional and absolute recovery after the stress cannot be fully explained by considering only the spatial extent of broken /spl equiv/Si-H bonds, as is done by 2-D R-D model. Additional contribution due to broken /spl equiv/Si-O bonds also plays a major role in determining the overall N/sub IT/ generation and recovery behavior.     

Photoelectrochemical cells with mixed polycrystalline n-type CdSPbS and CdSCdSe electrodes

The photoelectrochemical behaviour of n-type CdS (polycrystalline) containing small amount of PbS or CdSe in S^2? /S^2?_n redox system has been studied. Mixed polycrystalline n-type CdSPbS electrodes were prepared by electrodeposition and the n-type CdSCdSe electrodes were made by partial replacement of sulphide ions of CdS electrode with selenide ions from a solution of sodium selenosulphate. It has been observed that both the mixed chalcogenide electrodes exhibit better photoresponse than the simple CdS electrode.     

CHISEL programming operation of scaled NOR flash EEPROMs-effect of voltage scaling, device scaling and technological parameters

The impact of programming biases, device scaling and variation of technological parameters on channel initiated secondary electron (CHISEL) programming performance of scaled NOR Flash electrically erasable programmable read-only memories (EEPROMs) is studied in detail. It is shown that CHISEL operation offers faster programming for all bias conditions and remains highly efficient at lower biases compared to conventional channel hot electron (CHE) operation. The physical mechanism responsible for this behavior is explained using full band Monte Carlo simulations. CHISEL programming efficiency is shown to degrade with device scaling, and various technological parameter optimization schemes required for its improvement are explored. The resulting increase in drain disturbs is also studied and the impact of technological parameter optimization on the programming performance versus drain disturb tradeoff is analyzed. It is shown that by judicious choice of technological parameters the advantage of CHISEL programming can be maintained for deeply scaled electrically erasable programmable read-only memory (EEPROM) cells.     

Power reduction methods for NMOS dynamic random access memories

Power reduction methods for NMOS dynamic random access memories are proposed which reduce power dissipation. As the bit density increases in NMOS dynamic random access memories the power dissipation increases. A major consideration in the design of megabit dynamic random access memories is the power supply voltage. The power supply voltage mainly depends upon the following factors: power dissipation; reliability, such as high field effects due to small device size; memory cell operating margin. Power dissipation in decoders and 1 megabit NMOS dynamic random access memory chips are discussed. The basic properties of the proposed methods and a prototype VLSI implementation are discussed. In order to meet user power supply requirements, the proposed power reduction methods are useful for future megabit NMOS dynamic random access memories.     

Secure energy aware routing protocol for trust management using enhanced Dempster Shafer evidence model in multi-hop UWAN

Wireless Networks - At present, underwater wireless ad hoc networks (UWAN) are widely used in enormous applications. At the same time, UWAN faced many security issues, like energy leaks. The energy...     

A secure multi-hop relay node selection scheme based data transmission in wireless ad-hoc network via block chain

In today’s scenario, data transmission is established through the single or multi-hop relay nodes in Wireless Ad-Hoc Networks (WANET). Traditional relay node selection techniques undergo collusion attacks, increased energy consumption, delay, and reduced network lifetime. To cope with these problems, we propose a Quantum Atom Search Optimization coupled with Blockchain aided Data Transmission (QASO-BDT) scheme for a relay node selection with security aided data transmission. This approach comprises three phases such as registration, clustering, and transmission. Initially, in the node registration phase every sensor node gets registered in the blockchain network through Capillary Gateway (CG). Next, in the clustering phase, a CH is selected and an enhanced multi-view clustering model is used to cluster the nodes into several clusters. Finally, the multi-hop transmission phase assists in best relay node selection for multi-hop transmission using QASO, and the blockchain-based transaction is carried out to ensure security in the system. The proposed scheme is simulated in the MATLAB platform and achieves a result of 91.5% throughput, the reduced energy value of 40%, end to end delay of 20.6%, and the exhaustion of node is 1% which results in an increased lifetime of the nodes. Also, security is evaluated in comparison with other traditional methods.