Influence of microstructure on cavitation in the heat affected zone of a Grade 92 steel weld during long-term high temperature creep

The microstructure in the heat affected zone of the multi-pass welds constructed using the 9% Cr tempered martensitic steels is complex and susceptible to premature creep failure. In the present research, a systematic investigation has been conducted after long-term creep exposure in the heat affected zone of a multi-pass weld on the 9% Cr Grade 92 steel to identify the sub-optimal microstructures with a high susceptibility to creep cavitation. The characterisation techniques employed include hardness mapping and a range of electron-based microscopy methods. The results provide quantitative data for microstructure and creep cavities. In this case, preferential creep cavitation has been confirmed in the regions within the heat affected zone that possesses a microstructure with an inhomogeneous distribution of the M23C6 carbides and a refined martensitic grain structure. Creep cavities have been observed on the secondary phase particles including the Al2O3, the MnS and the BN phases. The observations from the current research confirm that creep cavitation preferentially occurs in the partially-transformed zones that were subjected to thermal cycles associated with peak temperatures between the Ac1 and the Ac3 transus temperatures during weld fabrication

Interaction of Brain-Derived Neurotrophic Factor with the Effects of Chronic Methamphetamine on Prepulse Inhibition in Mice Is Independent of Dopamine D3 Receptors

The aim of the present study was to gain a better understanding of the role of brain-derived neurotrophic factor (BDNF) and dopamine D3 receptors in the effects of chronic methamphetamine (METH) on prepulse inhibition (PPI), an endophenotype of psychosis. We compared the effect of a three-week adolescent METH treatment protocol on the regulation of PPI in wildtype mice, BDNF heterozygous mice (HET), D3 receptor knockout mice (D3KO), and double-mutant mice (DM) with both BDNF heterozygosity and D3 receptor knockout. Chronic METH induced disruption of PPI regulation in male mice with BDNF haploinsufficiency (HET and DM), independent of D3 receptor knockout. Specifically, these mice showed reduced baseline PPI, as well as attenuated disruption of PPI induced by acute treatment with the dopamine receptor agonist, apomorphine (APO), or the glutamate NMDA receptor antagonist, MK-801. In contrast, there were no effects of BDNF heterozygosity or D3 knockout on PPI regulation in female mice. Chronic METH pretreatment induced the expected locomotor hyperactivity sensitisation, where female HET and DM mice also showed endogenous sensitisation. Differential sex-specific effects of genotype and METH pretreatment were observed on dopamine receptor and dopamine transporter gene expression in the striatum and frontal cortex. Taken together, these results show a significant involvement of BDNF in the long-term effects of METH on PPI, particularly in male mice, but these effects appear independent of D3 receptors. The role of this receptor in psychosis endophenotypes therefore remains unclear

Making commercial bracelet smarter with a biochemical button module

Making commercial bracelet smarter with a biochemical button modul

Local Surveillance of the COVID-19 Outbreak

Given the worldwide pandemic of the novel coronavirus disease 2019 (COVID-19) and its continuing threat brought by the emergence of virus variants, there are great demands for accurate surveillance and monitoring of outbreaks. A valuable metric for assessing the current risk posed by an outbreak is the time-varying reproduction number ((Formula presented.)). Several methods have been proposed to estimate (Formula presented.) using different types of data. We developed a new tool that integrated two commonly used approaches into a unified and user-friendly platform for the estimation of time-varying reproduction numbers. This tool allows users to perform simulations and yield real-time tracking of local epidemic of COVID-19 with an R package

Mathematical modelling and simulation for hydrating backfill body under cemented paste backfill/rock interface loading

Cemented paste backfill (CPB)/rock interface shear resistance results in a spatiotemporal stress reduction in CPB and thus affects the mechanical stability of CPB structure in underground excavations. To study the stress distribution in CPB structure, an integrated model consisting of a cohesive zone model for CPB/rock interface behavior and a multiphysics model for hydrating CPB behavior is developed. The predictability of the proposed model is validated against measurements from laboratory tests and field studies. Thereafter, the validated model is used to investigate the influence of curing time, stope geometry, and field backfilling operation on the spatiotemporal stress development in CPB structure. It has been found that the CPB/rock interface loading is able to reduce the stress levels in CPB by up to 75%, and taking advantage of this phenomenon can significantly reduce the operation cost. Moreover, there exists a critical stope width that governs the extent of stress reduction in CPB. In addition, continuous mining activity in the secondary stope exerts limited impact on the stress redistribution in the primary backfill body. These findings provide practical guidance for the safe design of a CPB structure as well as a more strategic mining plan for the adjacent ore body

Mitigating thermal expansion effects in solid oxide fuel cell cathodes: A critical review

Solid oxide fuel cells (SOFCs) are a promising technology for clean electricity generation. However, their performance degradation over time and with thermal cycles due to thermal incompatibility remains a significant challenge in achieving the industrial scale. Designing a thermally compatible cathode material to overcome this issue is essential to withstand more thermal cycles. Rather than reviewing the cathode materials, this review critically examines recent advances in mitigating cathode/electrolyte thermal incompatibility and delamination via designing cathode materials and cathode-electrolyte interfaces. This critical review provides an overview of SOFC application, significant challenges, and the delamination mechanism, followed by an elaboration on experimental strategies to tailor the thermal expansion of cathodes to reduce or eliminate cathode delamination. In the last section, the remaining challenges and future research opportunities are discussed to support the design of thermally compatible cathode materials for SOFCs with high durability.</p

EDIndex: Enabling Fast Data Queries in Edge Storage Systems

In an edge storage system, popular data can be stored on edge servers to enable low-latency data retrieval for nearby users. Suffering from constrained storage capacities, edge servers must process users' data requests collaboratively. For sourcing data, it is essential to find out which edge servers in the system have the requested data. In this paper, we make the first attempt to study this edge data query (EDQ) problem and present EDIndex, a distributed Edge Data Indexing system to enable fast data queries at the edge. First, we introduce a new index structure named Counting Bloom Filter (CBF) tree for facilitating edge data queries. Then, to improve query performance, we enhance EDIndex with a novel index structure named hierarchical Counting Bloom Filter (HCBF) tree. In EDIndex, each edge server maintains an HCBF tree that indexes the data stored on nearby edge servers to facilitate data sourcing between edge servers at the edge. The results of extensive experiments conducted on an edge storage system comprised of 90 edge servers demonstrate that EDIndex 1) takes up to 8.8x less time to answer edge data queries compared with state-of-the-art edge indexing systems; and 2) can be implemented in practice with a high query accuracy at low initialization and maintenance overheads

A novel premixing strategy for highly sensitive detection of nitrite on paper-based analytical devices

A novel premixing strategy for highly sensitive detection of nitrite on paper-based analytical device

A high-resolution wave energy assessment of south-east Australia based on a 40-year hindcast

In this study, a third-generation ocean wave model (WAVEWATCH III; WW3) implemented on a high-resolution unstructured grid was developed to investigate wave energy in the south-east of Australia over the 40-year period from 1981 to 2020. The simulated wave power shows good agreement with values estimated from multiplatform satellite data. Thus, the modeled data were used to study statistics (mean conditions, seasonality, extremes, and long-term trends) of wave power in the domain, which show impacts of Southern Ocean swell and protection provided by the land mass of Tasmania. The results indicate increasing wave power trends, with the largest values in the southeastern part of the domain over the 40-year period. These positive trends are mainly a result of an increase in significant wave height rather than peak wave period. By utilizing the simulated wave properties, we estimated regional annual electric power at 14 coastal locations using 9 typical wave energy converters (WECs). To do so, we conducted a comprehensive analysis (seasonal variations, wave power roses, probability distributions, and bivariate probability distributions) at these locations. The results demonstrate that the western and southwestern coasts of the domain are promising generation sites but with large seasonal variability. The central and eastern coasts are protected by Tasmania, and exhibit more stable conditions but are far less energetic for electricity production. This study has critical implications for the region, which provides a benchmark for coastal WEC deployment

Effect of Bacillus Subtilis on Immune Function of Hd11 Chicken Macrophages

ABSTRACT Poultry is frequently contaminated by Salmonella, a pathogen leading to human health concern worldwide. This study aimed to evaluate the effect of Bacillus subtilis (BS)strain 048 (BS048) on the activation, phagocytosis, sterilization, cytokine secretion, and nitrogen oxide synthesis of HD11 chicken macrophages subjected to Salmonella enteritidis challenge, using lipopolysaccharide treatment as a negative control. The results showed: (1) BS048 had no significant effect on extracellular lactate dehydrogenase activity (p>0.05), while lipopolysaccharide treatment significantly increased extracellular lactate dehydrogenase activity (p</div