Search

Recently, manufacturing companies have been making efforts to increase resource utilization while ensuring the flexibility of production lines to respond to rapidly changing market environments and customer demand. In the high-tech manufacturing industry, which requires expensive manufacturing facilities and is capital-intensive, re-entrant production lines are used for efficient production with limited resources. In such a production system, a part visits a specific station repeatedly during the production period. However, a re-entrant production line requires an appropriate scheduling system because other parts with different processing requirements are processed at the same station. In this study, a re-entrant production line was modeled as a manufacturing environment via simulation, and an adaptive scheduling system was developed to improve its operational performance by applying deep reinforcement learning (DRL). To achieve this, a software architecture for integrating DRL with the simulation was developed and the states, actions, and rewards of the reinforcement learning (RL) agent were defined. Moreover, a discrete-event simulation control module was designed to collect data from the simulation model and evaluate the policy network trained via DRL. Finally, the applicability and effectiveness of the developed scheduling system were verified by conducting experiments on a hypothetical re-entrant production line. [ABSTRACT FROM AUTHOR]

With the increasing dynamic nature of customer demand, production, product, and manufacturing design changes have become more frequent. Moreover, inadequate validation during the manufacturing design phase may result in additional issues, such as process redesign and layout reallocation, during the operation phase. Therefore, systems that can pre-validate and allow accurate and reliable analysis in the manufacturing design phase, as well as apply and optimize variations in production lines in real time, are required. Previously, digital twin (DT) has been studied a lot in product design and facility prognostics and management fields. Research on the system framework leading to DT utilization and optimization and analysis through DT in complex manufacturing systems with continuous processes such as production lines is insufficient. In this study, a system based on a DT and simulation results is developed; this system can reflect, analyze, and optimize dynamic changes in the design of processes and production lines in real time. First, the framework and application of the proposed system are designed. Subsequently, optimization methodologies based on heuristics and reinforcement learning (RL) are developed. Finally, the effectiveness and applicability of the proposed system are verified by implementing an actual DT application at a real manufacturing site. [ABSTRACT FROM AUTHOR]

All-solid-state batteries (ASSBs) with inorganic solid electrolytes (SEs) have received much attention as future energy storage systems owing to their high energy densities and excellent safety. Sulfide-based SEs are considered promising because they exhibit greater ionic conductivities and mechanical softness than oxide-based SEs. In particular, argyrodite-type Li6PS5Cl with a high ionic conductivity of 3.0 × 10−3 S cm−1 offers new possibilities for realizing high-performance ASSBs. However, contact with moisture results in the evolution of H2S from Li6PS5Cl, which has hindered the scalable fabrication and practical application of Li6PS5Cl. To avoid this issue, we propose incorporating a zeolite, which can act as a scavenger for both toxic H2S gas and moisture, as a functional additive in Li6PS5Cl. We demonstrate that zeolite-embedded Li6PS5Cl exhibits greatly improved chemical stability and reduced H2S evolution upon storage in humid air (RH 50%), leading to a noticeable improvement in the cycle performance of ASSBs. This approach could resolve the technical issues associated with sulfide-based SEs toward commercial-scale implementation. [ABSTRACT FROM AUTHOR]

Deoxygenation of various types of N-oxides including both heterocyclic and alkyl(aryl)amine derivatives has successfully been developed by the copper-catalyzed oxygen atom transfer using diazo compounds as the oxygen acceptor. The reaction proceeds smoothly over a broad range of substrates with excellent functional group tolerance under mild conditions. [ABSTRACT FROM AUTHOR]

The Ir-catalyzed mild CH amidation of benzoic acids with sulfonyl azides was developed to give reactions with high efficiency and functional-group compatibility. Subsequent protodecarboxylation of ortho-amidated benzoic acid products afforded meta- or para-substituted ( N-sulfonyl)aniline derivatives, the latter being inaccessible by other CH functionalization approaches. The decarboxylation step was compatible with the amidation conditions, enabling a convenient one-pot, two-step process. [ABSTRACT FROM AUTHOR]

Direct CH amidation of arylphosphoryl compounds has been developed by using an IrIII catalyst system under mild conditions. A wide range of substrates could be employed with high functional-group tolerance. This procedure was successfully applied for the first time to the asymmetric reaction giving rise to a P-chirogenic center with a high diastereomeric ratio of up to 19:1 (90 % de). [ABSTRACT FROM AUTHOR]

The manufacturing industry has witnessed rapid changes, including unpredictable product demand, diverse customer requirements, and increased pressure to launch new products. To deal with such changes, the reconfigurable manufacturing system has been proposed as one of the advanced manufacturing systems that is close to the realisation of smart manufacturing since it is able to reconfigure its hardware, software, and system structures in a much quicker manner. Conventional simulation technologies lack convergence with physical manufacturing systems, and reconfigurable manufacturing lines require the manual construction of production line models for each reconfiguration. This study presents a digital twin-based integrated reconfiguration assessment application that synchronises with real-time manufacturing data and provides accurate, automated simulation functionality to build and analyse a manufacturing system. The paper discusses the architectural design and implementation of the application, an information model, and an assessment model that enable quantitatively assessment on reconfigurations of manufacturing systems from various aspects. The effectiveness of the proposed application is verified via application to an automotive parts production line to assess the reconfiguration indicators of the manufacturing system under different scenarios. The results reveal that the proposed application provides faster and more accurate reconfiguration assessments compared to existing methods. The findings of this study are expected to facilitate accurate and consistent decision making for evaluating the various indicators of production line performance. [ABSTRACT FROM AUTHOR]

Abstract: Glue is widely used to improve the reliability of ball grid array (BGA) under mechanical shock and vibration. Although it has been demonstrated to have a positive effect on the reliability of BGA under mechanical impact, it can have adverse effects on BGA under thermal cycling. This paper investigates the effect of glue on the reliability of BGA under thermal cycling using both experimental and numerical methods. The digital image correlation (DIC) technique was used to obtain the thermal mechanical behavior of the package. The experimental results explain in detail how the glue negatively affects the reliability of the BGA. Furthermore, a finite element analysis was performed and its results were verified with experimental results. A numerical parametric study was carried out on various mechanical properties, configurations of the glue, and introduction of a stiffener using the validated FEM model. The results show that the reliability of BGA strongly depends on geometries and material properties of the glue. Based on the results, a guideline of glue selection for BGA reliability under thermal cycling is formulated. [Copyright &y& Elsevier]

Background: Although sarcopenia has been reported to predict survival in cancer patients, its impact on patients who received immune checkpoint inhibitors (ICIs) has not been thoroughly investigated. This systematic review aimed to assess the long-term oncologic impact of sarcopenia on patients who received ICIs. Methods: A systematic review of studies indexed in the PubMed, Embase, and Cochrane databases, up to April 1, 2021, was conducted. Studies that reported hazard ratios (HRs) for overall survival (OS) and progression-free survival (PFS) based on sarcopenia in patients treated with ICIs were included. The inverse variance method was used with a random-effects model for data analysis. Results: A total of 1284 patients from 14 studies were included. Among the patients who received ICIs, patients with sarcopenia had a significant increase in overall mortality compared to patients without sarcopenia in univariate analyses (HR = 1.66, 95% CI = 1.20–2.29, p = 0.002) and in adjusted HRs (HR = 1.55, 95% CI = 1.15–2.10, p = 0.004). The same results were obtained for PFS by both univariate analysis (HR = 1.75, 95% CI = 1.37–2.23, p < 0.001) and adjusted HRs (HR = 1.63, 95% CI 1.28–2.09, p < 0.001). Conclusions: Sarcopenia appears to be an effective biomarker for predicting long-term oncologic outcomes in patients receiving ICI therapy and hence plays an important role when making treatment decisions. However, the fundamental role of this association with survival should be further investigated in large cohorts and clinical trials. [ABSTRACT FROM AUTHOR]

This study is aimed at preparing C8–C16 alkene through oligomerization of a butene mixture using nickel oxide supported on mesoporous aluminosilicate. Mesoporous aluminosilicate with an ordered structure was successfully synthesized from HZSM-5 zeolite by combining a top-down and a bottom-up method. MMZZSM-5 catalyst showed much higher butene conversion and C8–C16 yield in the butene oligomerization reaction than those with HZSM-5. This is attributed to the pore geometry of MMZZSM-5, which is more beneficial for internal diffusion of reactants, reaction intermediates, and products. The ordered channel-like mesopores were maintained after the nickel-loading on MMZZSM-5. The yield for C8–C16 hydrocarbons over NiO/MMZZSM-5 was higher than that of MMZZSM-5 catalyst, which seemed to be due to higher acid strength from a higher ratio of Lewis acid to Brønsted acid. The present study reveals that a mesoporous NiO/MMZZSM-5 catalyst with a large amount of Lewis acid sites is one of the potential catalysts for efficient generation of aviation fuel through the butene oligomerization. [ABSTRACT FROM AUTHOR]

Procedure A) is found to be optimal for the introduction of an amino function in ortho-position to the carboxylic acid by use of different sulfonyl azides. [ABSTRACT FROM AUTHOR]

An iridium(III)-catalyst system allows the direct amidation of arylphosphoryls with various sulfonyl azides under mild conditions and for the first time in an asymmetric manner. [ABSTRACT FROM AUTHOR]

50 examples [ABSTRACT FROM AUTHOR]