An alternative solution of the neutron diffusion equation in cylindrical symmetry

Alternative analytical solutions of the neutron diffusion equation for both infinite and finite cylinders of fissile material are formulated using the homotopy perturbation method. Zero flux boundary conditions are investigated on boundary as well as on extrapolated boundary. Numerical results are provided for one-speed fast neutrons in ²³⁵U. The results reveal that the homotopy perturbation method provides an accurate alternative to the Bessel function based solutions for these geometries.     

Annealing temperature effect on structural and morphological properties of nano photonic LiNbO<Subscript>3</Subscript>

In this work, thermal annealing processes was depended in order to prepare (Δ) phase LiNbO₃ and the properties of nanostructure films was characterized. The sol–gel method was used to grow and deposit high purity Lithium-Niobate Nano and Micro-structure on a quartz substrate, at three different annealing temperatures. The structural, morphological, and optical properties of grown films have been investigated using X-ray diffraction, scanning electron microscopy, atomic force microscopy, optical study through Raman spectroscopy, UV–Vis and Photoluminescence. The measurements showed that the structure was crystalline in nature and the grains are regularly distributed within the film as a result of increasing the annealing temperature. This observation is typically used in optical waveguides and other optoelectronics applications.     

Some mechanical and thermal properties of clay bricks for the Jordan valley region

An experimental investigation was carried out to study the use of different locally available additives to Al-Karamah clay to produce bricks to suit the weather conditions in the Jordan Valley region. The parameters investigated were the percentages of additives by volume, compaction rate, and drying rate. The ultimate compressive strength and thermal properties of the bricks were measured. The study indicated that Al-Karamah clay can be used successfully to manufacture solid clay bricks which suit the Jordan Valley region.     

Envelope detection and correction of SSB

Envelope detection is significantly less complex to implement and use than coherent detection if applied to SSB results in gross distortion unless the carrier component is very large. A method of correcting this distortion is discussed and a variant which achieves partial correction with some hardware simplification is investigated. Computer simulation shows that a reduction of 15 dB in second-harmonic distortion can be achieved, and this is confirmed by tests on a prototype system.     

A chemically amplified fullerene-derivative molecular electron-beam resist

Current lithographic resists depend on large polymeric materials, which are starting to limit further improvements in line-width roughness and feature size. Fullerene molecular resists use much smaller molecules to avoid this problem. However, such resists have poor radiation sensitivity. Chemical amplification of a fullerene derivative using an epoxy crosslinker and a photoacid generator is demonstrated. The sensitivity of the material is increased by two orders of magnitude, and 20-nm line widths are patterned.     

Characterization of Critical Determinants of ACE2–SARS CoV-2 RBD Interaction

Despite sequence similarity to SARS-CoV-1, SARS-CoV-2 has demonstrated greater widespread virulence and unique challenges to researchers aiming to study its pathogenicity in humans. The interaction of the viral receptor binding domain (RBD) with its main host cell receptor, angiotensin-converting enzyme 2 (ACE2), has emerged as a critical focal point for the development of anti-viral therapeutics and vaccines. In this study, we selectively identify and characterize the impact of mutating certain amino acid residues in the RBD of SARS-CoV-2 and in ACE2, by utilizing our recently developed NanoBiT technology-based biosensor as well as pseudotyped-virus infectivity assays. Specifically, we examine the mutational effects on RBD-ACE2 binding ability, efficacy of competitive inhibitors, as well as neutralizing antibody activity. We also look at the implications the mutations may have on virus transmissibility, host susceptibility, and the virus transmission path to humans. These critical determinants of virus–host interactions may provide more effective targets for ongoing vaccines, drug development, and potentially pave the way for determining the genetic variation underlying disease severity.     

Superquantile-Based Learning: A Direct Approach Using Gradient-Based Optimization

Journal of Signal Processing Systems - We consider a formulation of supervised learning that endows models with robustness to distributional shifts from training to testing. The formulation hinges...