Hot Corrosion Behaviour of Detonation-Gun Sprayed Cr3C2–NiCr Coating on Inconel-718 in Molten Salt Environment at 900 °C

Detonation gun sprayed Cr₃C₂–NiCr coating was deposited on nickel-based superalloy Inconel-718. Hot corrosion studies were conducted on uncoated as well as Cr₃C₂–NiCr coated superalloy in 75 wt% Na₂SO₄ + 25 wt% NaCl salt environment at 900 °C for 50 cycles. The thermo-gravimetric technique was used to establish kinetics of corrosion. X-ray diffraction and scanning electron microscopy/energy-dispersive X-ray analysis techniques were used to analyze the corrosion products. The uncoated superalloy suffered intense spalling, while the Cr₃C₂–NiCr coating provided good protection against hot corrosion in the given salt environment.     

Agave sisalana,a biosorbent for the adsorption of Reactive Red 120 from aqueous solution

The textile industry is one of the largest producers of dye effluent. Treatment of these effluents has to be cost effective hence a number of precursors have been studied as a viable alternative adsorbent. Sisal fibre was converted to activated carbon by chemical methods. Sisal fibre was activated with different activating agents such as H₃PO₄, HCl, HNO₃, NaOH and KOH. The adsorption of Reactive Red 120 (RR 120) dye onto sisal fibre activated carbon (SFAC) from aqueous solution was investigated. Adsorption experiments were carried out at different dye concentrations, initial solution pH and carbon dosage. Batch adsorption studies were carried out using activated carbon produced using phosphoric acid yielded better carbon as it good results in terms of Methylene Blue number and Iodine number. These carbons were used to study the batch adsorption studies. Methylene Blue number and Iodine number of SFAC were found to be 240 mg/g and 855 mg/g, respectively. The BET surface area of the carbon was 885 m²/g. The batch experiments adsorption isotherm studies fitted well to Langmuir isotherm and the adsorption capacity was found to be 110 mg/g. Adsorption kinetics data were tested using pseudo-first-order and pseudo-second-order models. Kinetic studies showed that the adsorption data followed a pseudo-second-order reaction.     

Characterization and Modeling of Laser Micromachined Periodically Corrugated Metallic Terahertz Wire Waveguides

Finite element method simulations of periodically corrugated metal terahertz wire waveguides have been conducted with concurrent analysis done on both the near-field confinement properties and the far-field emission properties at the end of the waveguides. This modeling was used to guide the choice of design parameters for the fabrication of waveguides with laser micromachining. The waveguides were characterized with a fiber-coupled terahertz time-domain spectroscopy and imaging system. The propagation properties as well as the frequency dependent diffraction at the end of the wire waveguides were examined and compared to straight, non-engineered metallic wire waveguides.     

Surface roughness of ion-bombarded Si(1 0 0) surfaces: Roughening and smoothing with the same roughness exponent

We have carried out scanning tunneling microscopy experiments under ultrahigh vacuum condition to study the roughness of pristine as well as ion-bombarded Si(1 0 0) surfaces and of ultrathin Ge films deposited on them. One half of a Si(1 0 0) sample (with native oxide layer) was irradiated at room temperature using 45 keV Si⁻ ions at a fluence of 4 × 10¹⁵ ions/cm² while the other half was masked. STM measurements were then carried out on the unirradiated as well as the irradiated half of the sample. Root-mean-square (rms) roughness of both the halves of the sample has been measured as a function of STM scan size. Below a length scale of ∼30 nm we observe surface smoothing and surface roughening is observed for length scales above this value. However, the surface is self-affine up to length scales of ∼200 nm and the observed roughness exponent of 0.46 ± 0.04 is comparable to earlier cases of ion sputtering studies where only roughening [J. Krim, I. Heyvart, D.V. Haesendonck, Y. Bruynseraede, Phys. Rev. Lett. 70 (1993) 57] or only smoothing [D.K. Goswami, B.N. Dev, Phys. Rev. B 68 (2003) 033401] was observed. Preliminary results involving morphology for Ge deposition on clean ion-irradiated and pristine Si(1 0 0) surfaces are presented.     

Designing fault-tolerant real-time computer systems with diversified bus architecture for nuclear power plants

Fault-tolerant real-time computer (FT-RTC) systems are widely used to perform safe operation of nuclear power plants (NPP) and safe shutdown in the event of any untoward situation. Design requirements for such systems need high reliability, availability, computational ability for measurement via sensors, control action via actuators, data communication and human interface via keyboard or display. All these attributes of FT-RTC systems are required to be implemented using best known methods such as redundant system design using diversified bus architecture to avoid common cause failure, fail-safe design to avoid unsafe failure and diagnostic features to validate system operation. In this context, the system designer must select efficient as well as highly reliable diversified bus architecture in order to realize fault-tolerant system design. This paper presents a comparative study between CompactPCI bus and Versa Module Eurocard (VME) bus architecture for designing FT-RTC systems with switch over logic system (SOLS) for NPP.     

Selected 1,3-Benzodioxine-Containing Chalcones as Multipotent Oxidase and Acetylcholinesterase Inhibitors

Chalcones are considered effective templates for the development of monoamine oxidase (MAO) and cholinesterase (ChE) inhibitors. The present work describes the syntheses of selected 1,3-benzodioxine-containing chalcones ( CD3, CD8 and CD10 ), and their inhibitory activities against MAO-A, MAO-B, acetylcholinesterase (AChE), and butyrylcholinesterase (BChE). Compound CD8 most potently inhibited MAO-B with an IC₅₀ value of 0.026 μM, followed by CD10 and CD3 (1.54 and 1.68 μM, respectively). CD8 potently and non-selectively inhibited MAO-A (IC₅₀ value of 0.023 μM). On the other hand, CD10 and CD8 inhibited AChE with IC₅₀ values of 5.40 and 9.57 μM, respectively. Kinetics and reversibility experiments showed that all synthesized molecules were competitive and reversible inhibitors, and the K_i values of CD8 for MAO-A and MAO-B were 0.018 and 0.0019 μM, respectively. By in vitro and in silico analyses, all compounds were found to have high passive human gastrointestinal absorptions, blood-brain barrier permeabilities, and non-toxicities. Molecular docking simulations revealed that docking affinity of each compound for MAO-B was higher than that for MAO-A. The results indicate that CD8 is a potent non-selective MAO inhibitor, and CD10 is an effective selective MAO-B inhibitor, and both possess AChE inhibitory activity. Therefore, we suggest that CD8 and CD10 be considered potential dual-targeting inhibitors of MAO and AChE for the treatment of various neurodegenerative disorders.     

Design and Performance Evaluation of Sub-10 nm Gaussian Doped Junctionless SOI and SELBOX FinFET

Silicon - In this paper influences of uniform and non-uniform doping on the performance of SOI and SELBOX FinFET at gate length of sub-7 nm are evaluated. Junctionless devices require very...     

Enhancement of condensate water quantity and coefficient of performance of an air conditioning system: An experimental study

The objective of the present work is to increase the quantity of condensate water from atmospheric air during the air conditioning (A/C) process by using two techniques: increasing moisture content in atmospheric air by adding steam and passing compressed air instead of atmospheric air, respectively. The experiment was performed with both capillary valve and thermostatic expansion valve operations for assessing the volume flow rates (VFRs) of condensate and coefficient of performance (COP) concerning the air A/C arrangement. The control valve operated for the steam supply case was at half valve opening and one-fourth opening, respectively. The R-22 refrigerant was used in this study. From this study, it was perceived that the condensate water quantity was increased by adding the moisture to the inlet air for the A/C system simultaneously with the usage of compressed air. Furthermore, the COP of the system was also compared to normal atmospheric air admission conditions. The compressed air and steam admission to the A/C system has shown a tremendous increase in COP together with the VFR of the system rather than atmospheric air admission conditions.     

Buoyancy forces and activation energy on the MHD radiative flow over an exponentially stretching sheet with second‐order slip

The current study explores the effects of second‐order slip and activation energy (AE) on the magnetohydrodynamic and radiative fluid flow caused by a surface with exponential stretching. The binary chemical reaction with mixed convection is considered in this physical model to discover the heat transfer phenomenon. The governing system of equations leads to a set of nonlinear ordinary differential equations by using scaling analysis. The transformed system is calculated computationally by using the most powerful Shooting procedure with the support of MATLAB software. The characteristics of various flow parameters on the governing flow field are exhibited pictorially and deliberated. The results revealed that the coefficient of heat and mass transfer upsurge with growing values of the second‐order slip parameter and skin friction coefficient has a reverse effect on the first‐order slip parameter. The thermal measure of the fluid in the presence of suction and slip conditions is seen to be lesser than that with the nonslip and nonsuction conditions. The heat measure of the fluid augments with the rising buoyancy parameter. The influence of slips coupled with AE is significant in the fluid flow and heat transfer characteristics. The outputs of the current investigation are validated by comparing the Nusselt number with the available results and are found to closely agree as a limiting case.     

Non-isothermal crystallization of Ziegler Natta i-PP-graphene nanocomposite: DSC and new model prediction

Crystallization occurs in processing i-PP-GnP nanocomposites, and these nanocomposites have the potential to replace traditional fillers and be used to fabricate advanced materials and technology. Therefore, this subject was comprehensively investigated by applying a recent crystallization model, non-isothermal DSC experiments, Raman spectroscopy, and WAXRD. The multi-layer GnP-induced nucleation and the crystal growth rates were modelled. The overall modelling effort generated new insights, results, and explanations. This study confirmed and elucidated, or refuted several published conclusions. It has also been reported that the present model can pursue differences in catalyst-mediated i-PP backbone defects (stereo and regio) by simulating the relative crystallization profile and determining the crystallization kinetic triplet (n, k _o, and E _a). The multiple roles played by GnP were underscored, which exceed what the related literature currently reports. The Raman and XRD work revealed the interaction between GnP and i-PP. The shear-induced dispersion of GnP that occurs during extrusion significantly affected i-PP crystal size distribution. The present approach can also assess the effects of catalyst type and structure, and backbone defect types and their distribution on the non-isothermal crystallization of, in general, polyolefin blends and nanocomposites.