Hydrolysis of Argyrodite Sulfide-Based Separator Sheets for Industrial All-Solid-State Battery Production

Researchers have been working for many years to find new material and cell systems that can be used as potential post-lithium-ion batteries. Among these, the all-solid-state battery is considered a promising candidate, with sulfide-based materials having essential advantages over other solid electrolyte materials, particularly in terms of their high ionic conductivity. A great challenge, however, is their high reactivity in contact with water, where harmful hydrogen sulfide (H₂S) is formed. Since H₂S formation has implications for both worker safety and material quality, it is important to quantify its impact. For this reason, this paper examines the relationship between the product properties and the H₂S formation as well as influences resulting from the production environment. Exemplary material states along the process chain of a wet coating process route are analyzed for the steps of storage, mixing, coating, drying, and densifying with Li₆PS₅Cl (LPSCl) as a solid electrolyte material. By determining the H₂S formation rate for sulfide-based separator sheets, it is shown that the water content in the surrounding atmosphere has the highest impact, while other investigated parameters are negligibly small in comparison. Among the product properties, the geometric surface and pore surface have a great influence. These results demonstrate the need for a controlled atmosphere in the production facilities at dew points of -40 to -50 °C. At those moisture levels, occupational safety and product quality are ensured for the investigated solid electrolyte sheets of LPSCl. This study is the first to provide quantitative data from the point of view of the production environment on the formation of H₂S gas when using solid sulfide electrolytes and can therefore serve as a guideline for equipment, material, and cell manufacturers.

Alterations in the Transcriptional Landscape Allow Differential Desiccation Tolerance in Clinical Cronobacter sakazakii

Cronobacter sakazakii is a typical example of a xerotolerant bacterium. It is epidemiologically linked to low-moisture foods like powdered infant formula (PIF) and is associated with high fatality rates among neonates. We characterized the xerotolerance in a clinically isolated strain, Cronobacter sakazakii ATCC™29544^T, and compared the desiccation tolerance with that of an environmental strain, C. sakazakii SP291, whose desiccation tolerance was previously characterized. We found that, although the clinical strain was desiccation-tolerant, the level of tolerance was compromised when compared with that of the environmental strain. Transcriptome sequencing (RNA-seq)-based deep transcriptomic characterization identified a unique transcriptional profile in the clinical strain compared with what was already known for the environmental strain. As RNA-seq was also carried out under different TSB growth conditions, genes that were expressed specifically under desiccated conditions were identified and denoted as desiccation responsive genes (DRGs). Interestingly, these DRGs included transcriptomic factors like fnr, ramA, and genes associated with inositol metabolism, a phenotype as yet unreported in C. sakazakii. Further, the clinical strain did not express the proP gene, which was previously reported to be very important for desiccation survival and persistence. Interestingly, analysis of the plasmid genes showed that the iron metabolism in desiccated C. sakazakii ATCC™29544^T cells specifically involved the siderophore cronobactin, encoded by the iucABCD genes. Confirmatory studies using quantitative reverse transcription-PCR (qRT-PCR) determined that, though the secondary desiccation response genes were upregulated in C. sakazakii ATCC™29544^T, the level of upregulation was lower than that in C. sakazakii SP291. All these factors may collectively contribute to the compromised desiccation tolerance in the clinical strain. IMPORTANCE Cronobacter sakazakii has led to outbreaks in the past, particularly associated with foods that are low in moisture content. This species has adapted to survive in low water conditions and can survive in such environments for long periods. These characteristics have enabled the pathogen to contaminate powder infant formula, a food matrix with which the pathogen has been epidemiologically associated. Even though clinically adapted strains can also be isolated, there is no information on how the clinical strains adapt to low moisture environments. Our research assessed the adaptation of a clinically isolated strain to low moisture survival on sterile stainless steel coupons and compared the survival with that of a highly desiccation-tolerant environmental strain. We found that, even though the clinical strain is desiccation-tolerant, the rate of tolerance was compromised compared with that of the environmental strain. A deeper investigation using RNA-seq identified that the clinical strain used pathways different from that of the environmental strain to adapt to low-moisture conditions. This shows that the adaptation to desiccation conditions, at least for C. sakazakii, is strain-specific and that different strains have used different evolutionary strategies for adaptation.

Kubernetes Cluster for Automating Software Production Environment

Microservices, Continuous Integration and Delivery, Docker, DevOps, Infrastructure as Code-these are the current trends and buzzwords in the technological world of 2020. A popular tool which can facilitate the deployment and maintenance of microservices is Kubernetes. Kubernetes is a platform for running containerized applications, for example microservices. There are two main questions which answer was important for us: how to deploy Kubernetes itself and how to ensure that the deployment fulfils the needs of a production environment. Our research concentrates on the analysis and evaluation of Kubernetes cluster as the software production environment. However, firstly it is necessary to determine and evaluate the requirements of production environment. The paper presents the determination and analysis of such requirements and their evaluation in the case of Kubernetes cluster. Next, the paper compares two methods of deploying a Kubernetes cluster: kops and eksctl. Both of the methods concern the AWS cloud, which was chosen mainly because of its wide popularity and the range of provided services. Besides the two chosen methods of deployment, there are many more, including the DIY method and deploying on-premises.