Sulfidation Characteristics of an Advanced Superalloy and Comparison with Other Superalloys Intended for Gas Turbine Use

Sulfidation may occur even in an overall oxidizing environment beneath a corrosion product which assumes the role of a diffusion barrier allowing sulfur species transport at a faster rate when compared with that of oxygen species. The current paper presents sulfidation characteristics of an advanced single-crystal nickel-based superalloy (ANS) and compares performance with IN 792 and CMSX-4 superalloys. The results showed that all the superalloys were highly vulnerable to sulfidation and their lives were significantly reduced. Among them, the ANS was more susceptible to sulfidation and its life was reduced considerably. This is attributed to the changed chemistry of the advanced alloy. The results for ANS are compared with its oxidation data and the difference in its behavior is discussed. A degradation mechanism, which represents the deterioration of ANS under sulfidation conditions, is proposed based on the results obtained from different techniques. Finally, the necessity of protective coatings for shielding against high temperature sulfidation for potential application in enhanced efficiency of gas turbine engines is emphasized.     

Applying forming simulation to process and tooling designs for minimizing springback in split dowel manufacturing

In this study, FEA simulations were conducted to analyze the forming and springback of a split dowel forming process. Through 96 simulations, the best dimensional quality product from the current production tooling was obtained. However, it still cannot meet the customer’s geometrical requirement, so a metal finish process (secondary operation) is required. In order to minimize manufacturing cost and time, the secondary operation is not desired. Therefore, a new forming process and die design were developed through many iterative FEA simulations. This new design adds a short coin bead on the seam line area of the split dowel. It has been found that the springback amount is almost eliminated and the product quality exceeds the customer’s geometry requirement. Through this real industry case study, it is shown that FEA simulation can be used to not only optimize the current process but also design a new process and tooling.     

Removal of toxic zinc from water/wastewater using eucalyptus seeds activated carbon: non‐linear regression analysis

In the present study, a novel activated carbon was prepared from low‐cost eucalyptus seeds, which was utilised for the effectively removal of toxic zinc from the water/wastewater. The prepared adsorbent was studied by Fourier transform infrared spectroscopy and scanning electron microscopic characterisation studies. Adsorption process was experimentally performed for optimising the influencing factors such as adsorbent dosage, solution pH, contact time, initial zinc concentration, and temperature for the maximum removal of zinc from aqueous solution. Adsorption isotherm of zinc removal was ensued Freundlich model, and the kinetic model ensued pseudo‐second order model. Langmuir monolayer adsorption capacity of the adsorbent for zinc removal was evaluated as 80.37 mg/g. The results of the thermodynamic studies suggested that the adsorption process was exothermic, thermodynamically feasible and impulsive process. Finally, a batch adsorber was planned to remove zinc from known volume and known concentration of wastewater using best obeyed model such as Freundlich. The experimental details showed the newly prepared material can be effectively utilised as a cheap material for the adsorption of toxic metal ions from the contaminated water.Inspec keywords: wastewater treatment, activated carbon, zinc, toxicology, regression analysis, Fourier transform infrared spectra, scanning electron microscopy, adsorption, pH, reaction kinetics, monolayers, thermodynamics, contaminationOther keywords: Zn, toxic metal ion adsorption, contaminated water, batch adsorber, exothermic process, thermodynamic process, Langmuir monolayer adsorption capacity, pseudosecond‐order model, kinetic model, Freundlich model, adsorption isotherm, aqueous solution, temperature value, initial zinc concentration, contact time, pH value, adsorbent dosage, scanning electron microscopic characterisation, Fourier transform infrared spectroscopy, nonlinear regression analysis, eucalyptus seed activated carbon, wastewater, toxic zinc removal     

MoS2/MoTe2 Heterostructure Tunnel FETs Using Gated Schottky Contacts

2D transition metal dichalcogenide based van der Waals materials are promising candidates to realize tunnel field effect transistors (TFETs) with a steep subthreshold swing (SS) for low‐power applications. Their atomically flat, self‐passivated layers offer potentially defect free interlayer tunneling. There are still several issues that need to be addressed to experimentally achieve a steep SS, e.g., the Schottky contacts, impact of thick layers, and device architecture with respect to gate configuration. This paper resolves these challenges by experimentally demonstrating MoS₂/MoTe₂ TFETs and their electrical characteristics, in conjunction with ab initio simulations and surface Kelvin probe microscopy. The Schottky barrier's effect at the contact regions are isolated by fabricating individual buried gates below the contacts. Devices with different top and bottom gate configurations are produced to understand the impact of gate placement on the heterostructure characteristics. Quantum transport simulations are performed on MoS₂/MoTe₂ multilayer stack to evaluate the impact of multiple layers on TFET performance, effect of gate placement, and the mechanism behind indirect tunneling over the heterojunction region. This work highlights the influence of the Schottky contacts, multiple layers and the role of different gate configurations on the band‐to‐band tunneling phenomenon in 2D heterojunction TFETs.     

Extraterrestrial Gynecology: Could Spaceflight Increase the Risk of Developing Cancer in Female Astronauts? An Updated Review

Outer space is an extremely hostile environment for human life, with ionizing radiation from galactic cosmic rays and microgravity posing the most significant hazards to the health of astronauts. Spaceflight has also been shown to have an impact on established cancer hallmarks, possibly increasing carcinogenic risk. Terrestrially, women have a higher incidence of radiation-induced cancers, largely driven by lung, thyroid, breast, and ovarian cancers, and therefore, historically, they have been permitted to spend significantly less time in space than men. In the present review, we focus on the effects of microgravity and radiation on the female reproductive system, particularly gynecological cancer. The aim is to provide a summary of the research that has been carried out related to the risk of gynecological cancer, highlighting what further studies are needed to pave the way for safer exploration class missions, as well as postflight screening and management of women astronauts following long-duration spaceflight.     

The Proteomic Landscape of Resting and Activated CD4+ T Cells Reveal Insights into Cell Differentiation and Function

CD4+ T cells (T helper cells) are cytokine-producing adaptive immune cells that activate or regulate the responses of various immune cells. The activation and functional status of CD4+ T cells is important for adequate responses to pathogen infections but has also been associated with auto-immune disorders and survival in several cancers. In the current study, we carried out a label-free high-resolution FTMS-based proteomic profiling of resting and T cell receptor-activated (72 h) primary human CD4+ T cells from peripheral blood of healthy donors as well as SUP-T1 cells. We identified 5237 proteins, of which significant alterations in the levels of 1119 proteins were observed between resting and activated CD4+ T cells. In addition to identifying several known T-cell activation-related processes altered expression of several stimulatory/inhibitory immune checkpoint markers between resting and activated CD4+ T cells were observed. Network analysis further revealed several known and novel regulatory hubs of CD4+ T cell activation, including IFNG, IRF1, FOXP3, AURKA, and RIOK2. Comparison of primary CD4+ T cell proteomic profiles with human lymphoblastic cell lines revealed a substantial overlap, while comparison with mouse CD+ T cell data suggested interspecies proteomic differences. The current dataset will serve as a valuable resource to the scientific community to compare and analyze the CD4+ proteome.     

Model-based mapping of reconfigurable image registration on FPGA platforms

Image registration is a computationally intensive application in the medical imaging domain that places stringent requirements on performance and memory management efficiency. This paper develops techniques for mapping rigid image registration applications onto configurable hardware under real-time performance constraints. Building on the framework of homogeneous parameterized dataflow, which provides an effective formal model of design and analysis of hardware and software for signal processing applications, we develop novel methods for representing and exploring the hardware design space when mapping image registration algorithms onto configurable hardware. Our techniques result in an efficient framework for trading off performance and configurable hardware resource usage based on the constraints of a given application. Based on trends that we have observed when applying these techniques, we also present a novel architecture that enables dynamically-reconfigurable image registration. This proposed architecture has the ability to tune its parallel processing structure adaptively based on relevant characteristics of the input images.