Search Results (4)

Using Molecular Dynamics (MD) and Monte Carlo (MC) simulations, we studied the grain boundary (GB) segregation under different temperatures and Cr concentrations in Ni-Cr alloys with two distinct grain-boundary structures, i.e., Σ5(310)[010] and Σ101(200)[100]. Temperature plays a minor influence on Cr segregation for Σ5(310)[010] GB, but Cr segregation rapidly diminishes with elevating temperatures for Σ101(200)[100] GB. We also used the synthetic driving force and corresponding identification methods to investigate the effect of Cr solute segregation on grain boundary stability. All Σ5(310)[010] models have multi-stage grain boundary migration at 800 K. In the first stage, the grain boundary’s slow acceleration time is related to solute concentration. The migration temperature can influence this phenomenon. As temperatures rise, the duration of this slow acceleration phase diminishes. No similar phenomenon was observed in the process of the grain boundary movement of Σ101(200)[100]. The influence of solute concentration on grain boundary migration is complicated. The segregation concentration at the grain boundary cannot be regarded as the only factor affecting the migration of the grain boundary because the Cr atom on the grain boundary does not move with the grain boundary. This work will also discuss the grain boundary migration‘s relationship with lattice distortion and grain boundary atom diffusion. The results and findings of this study provide further insights into the segregation-increase GB stabilization of NC Ni-Cr alloys. Full article

Vertical-cavity surface-emitting lasers (VCSELs) have made remarkable progress, are being used across a wide range of consumer electronic applications, and have particularly received much attention from the telecom and datacom industries. However, several constraints are thus currently being tackled to improve the device characteristics and modulation formats to meet the various demanding requirements of the future 800 GbE and 1.6 TbE Ethernet standards. This manuscript discusses the device characteristics and the key considerations in the device designs and optimizations. Finally, we elucidate the latest developments and vital features of modern 850 nm VCSELs for high-speed interconnects. Full article

The European bison is a non-model organism; thus, most of its genetic and genomic analyses have been performed using cattle-specific resources, such as BovineSNP50 BeadChip or Illumina Bovine 800 K HD Bead Chip. The problem with non-specific tools is the potential loss of evolutionary diversified information (ascertainment bias) and species-specific markers. Here, we have used a genotyping-by-sequencing (GBS) approach for genotyping 256 samples from the European bison population in Bialowieza Forest (Poland) and performed an analysis using two integrated pipelines of the STACKS software: one is de novo (without reference genome) and the other is a reference pipeline (with reference genome). Moreover, we used a reference pipeline with two different genomes, i.e., Bos taurus and European bison. Genotyping by sequencing (GBS) is a useful tool for SNP genotyping in non-model organisms due to its cost effectiveness. Our results support GBS with a reference pipeline without PCR duplicates as a powerful approach for studying the population structure and genotyping data of non-model organisms. We found more polymorphic markers in the reference pipeline in comparison to the de novo pipeline. The decreased number of SNPs from the de novo pipeline could be due to the extremely low level of heterozygosity in European bison. It has been confirmed that all the de novo/Bos taurus and Bos taurus reference pipeline obtained SNPs were unique and not included in 800 K BovineHD BeadChip. Full article

We experimentally evaluate the high-speed on–off keying (OOK) and four-level pulse amplitude modulation (PAM4) transmitter’s performance in C-band for short-reach optical interconnects. We demonstrate up to 100 Gbaud OOK and PAM4 transmission over a 400 m standard single-mode fiber with a monolithically integrated externally modulated laser (EML) having 100 GHz 3 dB bandwidth with 2 dB ripple. We evaluate its capabilities to enable 800 GbE client-side links based on eight, and even four, optical lanes for optical interconnect applications. We study the equalizer’s complexity when increasing the baud rate of PAM4 signals. Furthermore, we extend our work with numerical simulations showing the required received optical power (ROP) for a certain bit error rate (BER) for the different combinations of the effective number of bits (ENOB) and extinction ratio (ER) at the transmitter. We also show a possibility to achieve around 1 km dispersion uncompensated transmission with a simple decision feedback equalizer (DFE) for a 100 Gbaud OOK, PAM4, and eight-level PAM (PAM8) link having the received power penalty of around 1 dB. Full article