Laser beam welding of a low density refractory high entropy alloy

In particular,the effect of different pre-heating temperatures was examined. Due to the low ductility of the material, laser beam welding at room temperature resulted in the formations of hot cracks. Sound butt joints without cracks were produced using pre-heating to T≥600 ◦C. In the initial as-cast condition, the alloy consisted of coarse bcc grains with a small amount of lens-shaped C15 Laves phase particle

Human Cell Atlas and cell-type authentication for regenerative medicine

In modern biology, the correct identification of cell types is required for the developmental study of tissues and organs and the production of functional cells for cell therapies and disease modeling. For decades, cell types have been defined on the basis of morphological and physiological markers and, more recently, immunological markers and molecular properties. Recent advances in single-cell RNA sequencing have opened new doors for the characterization of cells at the individual and spatiotemporal levels on the basis of their RNA profiles, vastly transforming our understanding of cell types. The objective of this review is to survey the current progress in the field of cell-type identification, starting with the Human Cell Atlas project, which aims to sequence every cell in the human body, to molecular marker databases for individual cell types and other sources that address cell-type identification for regenerative medicine based on cell data guidelines

Structure and mechanical properties of near-eutectic refractory Al-Cr-Nb-Ti-Zr high entropy alloys

In this study, the structure and mechanical properties of the near-eutectic refractory Al₂₄Cr₁₁Nb₁₁Ti₃₇Zr₁₇, Al₂₀Cr₂₀Nb₂₅Ti₂₅Zr₁₁₀, and Al₂₈Cr₁₅Nb₁₅₅Ti₂₀Zr₂₂ (at.%) high entropy alloys were investigated. Both the Al₂₄Cr₁₁₁Nb₁₁Ti₃₇₇Zr₁₇ and Al₂₀Cr₂₀Nb₂₅Ti₂₂₅Zr₁₀₀ alloys had a hypoeutectic structure, while the Al₂₈Cr₁₅Nb₁₅Ti₂₀Zr₂₂ alloy had a hypereutectic one. The proeutectic phase in the Al₂₄Cr₁₁Nb₁₁Ti₃₇Zr₁₇ and Al₂₀Cr₂₀Nb₂₅Ti₂₅Zr₁₀ alloys was the ordered B2 phase and in the Al₂₈Cr₁₅Nb₁₅Ti₂₀Zr₂₂ alloy - the C14 Laves phase. In all three alloys, the eutectic regions possessed a fine lamellar structure composed of a mixture of the C14 Laves and B2 phases. The densities of the alloys were 5.20-5.89 g/cm

NIPPLE DISCHARGE

According to the data available in the literature, as high as 50% of women have benign breast tumors frequently accompanied by nip- ple discharge. Nipple discharge may be serous, bloody, purulent, and colostric. The most common causes are breast abscess, injury, drugs, prolactinoma, intraductal pappiloma, ductal ectasia, intraductal cancer (not more than 10%)

Design and characterization of eutectic refractory high entropy alloys

Eutectic alloys are natural in-situ composites with near-equilibrium structures, impressive strength-ductility trade- off, and perfect castability. In the current study, novel eutectic Al-Cr-Nb-Ti-Zr refractory high entropy alloys (RHEAs) were designed using a CALPHAD (CALculation of PHAse Diagrams) approac

Aging behavior of two refractory Ti-Nb-(Hf, Zr)-Al high entropy alloys

In the present work, structure and mechanical properties of the Ti₄₀Nb₃₀Hf₁₅Al15 and Ti₄₀Nb₃₀Zr₂₀Al₁₀ refractory high entropy alloys after cold rolling to 80% reduction, recrystallization annealing at 900 °C for 15 min, and further aging treatment at T = 500, 600 and 700 °C for 1-96 h were studie

Negative Refractive Index in Artificial Metamaterials

We discuss optical constants in artificial metamaterials showing negative magnetic permeability and electric permittivity. Using effective field theory, we calculate effective permeability of nanofabricated media composed of pairs of identical gold nano-pillars with magnetic response in the visible spectrum.Comment: 16 pages, 4 figures, submitted to Optics Letter

Precipitation-hardened refractoryTi-Nb-Hf-Al-Ta high entropy alloys

This study reports the structure and mechanical properties of new refractory Ti₃₇.₅Nb₁₂.₅Hf₂₅Al₂₅, Ti₄₀Nb₃₀Hf₁₅Al₁₅, and Ti₄₀Nb₂₀Ta₁₀Hf₁₅Al₁₅ (at.%) high entropy alloys. After annealing at 1200 °C for 24 h, the program alloys had a single-phase B2 structure. Further annealing at 600 °C for 24 h resulted in the formation of Widmanstatten orthorhombic particles (O-phase) in the bcc matri

A new refractory Ti-Nb-Hf-Al high entropy alloy strengthened by orthorhombic phase particle

This study reports the structure and mechanical properties of a new refractory Ti₄₀Nb₃₀Hf₁₅Al₁₅ (at.%) high entropy alloy. The alloy was fabricated by vacuum arc melting and had a density of 7.07 ± 0.03 g/cm3. After annealing at 1200 °C for 24 h, the alloy possessed a single-phase B2 structure. Further annealing at 600 °C for 24 h resulted in the formation of Widmanstatten (Ti, Al)-rich orthorhombic particles (O-phase) in a bcc matri