Low-Temperature Synthesis of Fe-Doped ZnO Nanotubes

We report on the synthesis Zn_1?x Fe _x O nanotubes with average tube diameter of 60?nm to 100?nm and wall thickness of about 20?nm. The nanotubes were synthesized by a low-temperature electrochemical process, and their morphology was found to be sensitive to the electrolyte concentration and growth time. The maximum Fe doping achieved by this process was estimated to be approximately 4?wt.%. High-resolution transmission electron microscopy and x-ray diffraction showed good crystalline quality of the doped and undoped nanotubes with preferential growth along the wurtzite c-axis. The Fe-doped nanotubes exhibit wurtzite crystal structure with an increase in the c-axis lattice constant when compared with the undoped nanotubes, indicative of the fact that Fe ions substitute for Zn as 2+ ions in the ZnO crystal lattice. Further evidence of Fe as a substitutional dopant is provided by Raman and photoluminescence spectroscopy. A comparison of the effective magnetic moment in the undoped and doped nanotubes reveals the presence of four unpaired electrons in the Fe-doped sample and zero unpaired electrons for the undoped sample.     

Use of energy dispersive method with tungsten carbide opposed anvil high pressure set-up

The use of energy dispersive method has been discussed to record the X-ray diffraction data from a tungsten carbide opposed anvil high pressure set-up. It is pointed out that a proper collimation of the incident and the diffracted beams can eliminate the scattering from the gasket material. This results in an appreciable improvement in the quality of the recorded diffraction data. The choice of the various parameters has been discussed. The data on sodium chloride are presented in support of this analysis.     

Thermal performance of a parallel earth air-pipes system

In the present analysis the thermal performance of a parallel earth air-pipe system has been evaluated in terms of annual heating and cooling potential. The influence of the pipes on each other's thermal performance has been considered. The effect of seasonal variation of environmental parameters (ambient temperature, solar radiation, relative humidity, earth temperature etc.) has been considered. The results are obtained for the hot-dry climate of Jodhpur and the composite climate of Delhi. From the various possible earth surface treatments to increase the effectiveness of earth storage systems for air conditioning purposes, the results are presented for wet-shaded earth surface conditions, the most effective earth surface treatment for the climate considered. Thermal performance of the parallel air-pipe system is evaluated for the two cases. In the first case, inlet air temperature to the pipes is taken to be the hourly mean of the ambient air temperature of the average day of each month, and, in the second case, the inlet air temperature is taken to be equal to that of a conditioned room whose set-point temperature varies from month to month.     

Thermal performance of roof evaporative cooling and floor coupled evaporatively cooled underground water storage tank systems

The thermal performance of a room with two indirect evaporative cooling systems (operating independently and jointly) is analysed. The two evaporative systems considered are a water-film roof evaporative cooling system, and an underground water storage tank beneath the floor of the room. The water in the tank is evaporatively cooled through a suitable aeration system. The performance of the room is analysed in the hot-dry climate of Jodhpur and the composite climate of Delhi. It is found that the underground water storage system is marginally better than the roof evaporative cooling system for the Jodhpur and Delhi climates. A detailed parametric performance analysis of the room has also been carried out.     

Synthesis of CdS and alloyed CdMnS nanocrystals using aqueous foams

Certain surfactant-stabilized aqueous foams provide a potentially efficient and simple chemical route for the synthesis of various nanomaterials with controllable structure, size, and shape. In the present work, a one-step process for the synthesis of CdS and Cd1-xMn(x)S (0 < x < 10) nanocrystals has been described. Aqueous CdCl2 and the aerosol-OT solutions are homogeneously mixed together and thereafter, nitrogen is bubbled through this solution to produce stable aqueous foam. After drainage of the foam, the freestanding dry foam consisting of cadmium cations electrostatically complexed with the anionic aerosol-OT molecules at the liquid-gas interface is treated with H2S vapor. The foam turns yellowish-orange and collapses, in the process yielding CdS nanoclusters of variable morphology. This morphology variation is appropriately attributed to growth of the CdS as well as alloyed Cd1-xMn(x)S nanoparticles in different regions of the foam contributing to the varying topological structure. Optical absorption spectra of both CdS and Cd1-xMn(x)S nanoparticles clearly show a well-defined exciton absorption feature around 450 nm due to quantum confinement effects. The interesting band edge emission characteristics of these AOT-capped CdS and Cd1-xMn(x)S nanoparticles produced in the foam are discussed with respect to their size and shape. Particular interest in the present novel aqueous foam approach arises due to the fact that the cubic zincblende CdS and alloyed Cd1-xMn(x)S nanocrystals could easily be obtained even under ambient experimental conditions itself.     

HIoTPOT: Surveillance on IoT Devices against Recent Threats

Honeypot Internet of Things (IoT) (HIoTPOT) keep a secret eye on IoT devices and analyzes the various recent threats which are dangerous to IoT devices. In this paper, implementation of a research honeypot is presented which is used to learn the recent tactics and ethics used by black hat community to attack on IoT devices. As IoT is open and easy for accessing, all the intruders are highly attracted towards IoT. Recently Telnet based attacks are very famous on IoT devices to get easy access and attack on other devices. To reduce these kinds of threats, it is necessary to know in details about intruder, therefore the aim of this research work is to implement novel based secret eye server known as HIoTPOT which will make the IoT environment more safe and secure.     

Effect of PBMA on PVC‐based polymer blend electrolytes

Poly(vinyl chloride) (PVC)—poly(butyl methacrylate) (PBMA) blended polymer electrolytes with lithium perchlorate (LiClO₄) as the complexing salts are prepared by solution casting technique. The addition of PBMA into PVC matrix is found to induce considerable changes in physical and electrical properties of the polymer electrolytes. Addition of PBMA into PVC matrix is found to increase the conductivity by two orders of magnitude (1.108 × 10^?5 S cm^?1) when compared with that of the pristine PVC polymer electrolyte (10^?7 S cm^?1). Structural, thermal, mechanical, morphological, and polymer–salt interactions are ascertained from X‐ray diffraction (XRD), thermogravimetry/differential thermal analysis (TG/DTA), mechanical analysis, scanning electron microscope (SEM), and Fourier transform infrared spectroscopy (FTIR) respectively. A thermal stability upto 250 °C is asserted from the TG/DTA analysis. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44939.     

Fuzzy Based Collaborative Verification System for Sybil Attack Detection in MANET

Wireless Personal Communications - In mobile ad hoc network (MANET), the existing papers are two-level-hash technique reduces false positives however it does not verify the location and RSS...