39 research outputs found
The relationships between shop floor management and QCCs to support Kaizen
Purpose - The purpose of this study is to develop and redefine the ‘classic’ roles of shop floor management and Quality Control Cycles (QCCs) in Kaizen. In specific, it aims to examine the linkage between shop floor management and QCCs, and test the relationships among shop floor management, QCCs and long-term Kaizen improvement outcomes.
Design/methodology/approach – This study employs qualitative method by using a questionnaire to obtain data from 371 respondents in nine Sino-Japanese automotive joint-ventures. The data are analysed with the method of canonical correlation approach.
Findings – The study identifies important factors to assist the adoption of shop floor management and QCCs for Kaizen. The analysis on the survey indicates that not all the shop floor management tools could help to identify improvement opportunities. QCCs are effective in addressing large problems and challenging current policies in companies, however, they have low impacts on individual learning.
Research limitations/implications – The data of this study comes from nine Sino- Japanese automotive joint ventures. Therefore, the sample selection is limited in these companies. The findings are able to be applied for improving the similar problems which identified in this study. Practical implications – The study has the following practical implications, include the first one which is small shop floor problems can be identified and rapid solved continuously at source by shop floor management. The second one is QCCs, or other similar group-based improvement approaches take long to be fully addressed and implemented. Thirdly, practical solutions can be achieved from small and gradual changes, and they can prevent the results backsliding to the pre-improvement stage. Finally, QCCs are hardly to achieve a better improvement alone. It requires other Kaizen approaches to support.
Originality/value – This study is probably the first to explore and investigate the implementation of the four building block tools of shop floor management in real business practise, and more specific the first to discuss the relationship among shop floor management, QCCs and long-term improvement outcomes based on empirical data from Sino-Japanese automotive joint-ventures
Subliminal perception of others’ physical pain induces personal distress rather than empathic concern
Acknowledgements We thank the members of the research group for their revising this paper. Funding This research was supported by Humanities and Social Science Research Youth Fund Project of the Ministry of Education (19YJC190021) Grants to Juan Song. The funding body has no further role in the design of the study, data collection, analysis, data interpretation, and writing of the manuscript.Peer reviewedPublisher PD
Experimental investigations on drag-reduction characteristics of bionic surface with water-trapping microstructures of fish scales
Biological surfaces with unique wettability in nature have provided an enormous innovation for scientists and engineers. More specifically, materials possessing various wetting properties have drawn considerable attention owing to their promising application prospects. Recently, great efforts have been concentrated on the researches on wetting-induced drag-reduction materials inspired by biology because of their ability to save energy. In this work, the drag-reduction characteristics of the bionic surface with delicate water-trapping microstructures of fish Ctenopharyngodon idellus scales were explored by experimental method. Firstly, the resistance of smooth surface and bionic surface experimental sample at different speeds was carefully tested through the testing system for operation resistance. Then, the contact angle (CA) of fish scale surface was measured by means of the contact angle measuring instrument. It was discovered that the bionic surface created a rewarding drag-reduction effect at a low speed, and the drag-reduction rate significantly displayed a downward trend with the increase in flow speed. Thus, when the rate was 0.66 m/s, the drag-reduction effect was at the optimum level, and the maximum drag reduction rate was 2.805%, which was in concordance with the simulated one. Furthermore, a contact angle (CA) of 11.5° appeared on the fish scale surface, exhibiting fine hydrophilic property. It further manifested the spreading-wetting phenomenon and the higher surface energy for the area of apical of fish scales, which played an important role in drag-reduction performance. This work will have a great potential in the engineering and transportation field
Long-Term or Temporary? Hybrid Worker Recruitment for Mobile Crowd Sensing and Computing
This paper investigates a novel hybrid worker recruitment problem where the
mobile crowd sensing and computing (MCSC) platform employs workers to serve
MCSC tasks with diverse quality requirements and budget constraints, under
uncertainties in workers' participation and their local workloads.We propose a
hybrid worker recruitment framework consisting of offline and online trading
modes. The former enables the platform to overbook long-term workers (services)
to cope with dynamic service supply via signing contracts in advance, which is
formulated as 0-1 integer linear programming (ILP) with probabilistic
constraints of service quality and budget.Besides, motivated by the existing
uncertainties which may render long-term workers fail to meet the service
quality requirement of each task, we augment our methodology with an online
temporary worker recruitment scheme as a backup Plan B to support seamless
service provisioning for MCSC tasks, which also represents a 0-1 ILP problem.
To tackle these problems which are proved to be NP-hard, we develop three
algorithms, namely, i) exhaustive searching, ii) unique index-based stochastic
searching with risk-aware filter constraint, iii) geometric programming-based
successive convex algorithm, which achieve the optimal or sub-optimal
solutions. Experimental results demonstrate our effectiveness in terms of
service quality, time efficiency, etc
La\u3csub\u3e0.6\u3c/sub\u3eSr\u3csub\u3e1.4\u3c/sub\u3eMnO\u3csub\u3e4+δ\u3c/sub\u3e Layered Perovskite Oxide: Enhanced catalytic Activity for the Oxygen Reduction Reaction
Efficient electrocatalysts for the oxygen reduction reaction (ORR) is a critical factor to influence the performance of lithium–oxygen batteries. In this study, La0.6Sr1.4MnO4+δ layered perovskite oxide as a highly active electrocatalyst for the ORR has been prepared, and a carbon-coating layer with thickness \u3c5 nm has been successfully introduced to enhance the electronic conductivity of the as-prepared oxide. XRD, XPS, Raman, SEM and TEM measurements were carried out to characterize the crystalline structure and morphology of these samples. Rotating ring-disk electrode (RRDE) technique has been used to study catalytic activities of the as-prepared catalysts for the ORR in 0.1 M KOH media. RRDE results reveal that carbon-coated La0.6Sr1.4MnO4+δ exhibits better catalytic activity for the ORR. For the carbon-coated La0.6Sr1.4MnO4+δ, the ORR proceeds predominately via a direct four electron process, and a maximum cathodic current density of 6.70 mA cm−2 at 2500 rpm has been obtained, which is close to that of commercial Pt/C electrocatalyst under the same testing conditions
Assessment of CO2 enrichment mechanism in integrated coal gasification fuel cell combined cycle system with carbon capture
The present research proposes an innovative multi-physics coupled model of different configurations of an integrated coal gasification fuel cell combined cycle (IGFC) system employing Solid Oxide Electrolytic Cell (SOEC) for CO2 capture. Full-system simulation is carried out to examine efficiency. The model incorporates a Solid Oxide Fuel Cell (SOFC), a SOEC, a gas turbine (GT), and multiple recirculation loops operated by two ejectors. The results reveal that compared with traditional power plants, the proposed IGFC system equipped with SOEC can reduce CO2 emission by almost 80%, and operates environmentally beneficial. The efficiency of the system varies greatly depending on the design parameters implemented. The CO2 enrichment phenomenon by SOFC and capture measures of CO2 by SOEC are simultaneously analyzed. In addition, parametric analysis is performed to evaluate the coupling influence of multiple operating parameters on the IGFC system. Recirculation ratios of 0.75 with four times recirculations are found to be the optimal conditions for both SOFC fuel electrode and SOEC air electrode aimed at getting to the highest power generation efficiency and total CO2 capture rate of the system. After systematic optimization of the design parameters, the electrical efficiency and CO2 capture rate of the proposed system could achieve 68.47% and 87.88%, respectively, which are about 20% and 60% greater than those of traditional power plants. Furthermore, after optimizing the control strategy, the fuel utilization rate of the system increases from 63.09% to 83.40%
Preparation and Antihypertensive Effect of Microcapsules Containing Medicinal and Culinary Plant Materials and Angiotensin Converting Enzyme Inhibitory Peptide
In this study, the antihypertensive effect of microcapsules containing a mixture of goji berry, hawthorn and cassia seed at a mass ratio of 4:1:1 and angiotensin converting enzyme (ACE) inhibitory peptide in spontaneously hypertensive rats (SHR) was assessed. The ACE inhibition rate of the microcapsules containing the mixture and ACE inhibitory peptide at a mass ratio of 1:2 was 78.19%, which was significantly higher than those of the mixture of medicinal and culinary plant materials (69.46%) and ACE inhibitory peptide (71.48%) alone (P < 0.05). Under optimized encapsulation conditions (solid content of 10%, inlet air temperature of 160 ℃, core-to-wall ratio of 1:15, and a 1:4 mixture of modified starch and maltodextrin as wall material), an encapsulation efficiency of 82.76% was obtained. After intestinal digestion for 240 min, the release rate of the as-prepared microcapsules was 81.40%, and the bitter taste was significantly reduced (P < 0.05). Animal experiments showed that the microcapsules significantly reduced blood pressure in SHR, significantly increased the plasma contents of ACE2 and angiotensin 1-7 (Ang(1-7)), and reduced plasma ACE content and the contents of angiotensin II (AngII) in the plasma, heart, kidney and thoracic aorta (P < 0.05). The effect was more pronounced than those of the mixture of medicinal and culinary plant materials and ACE inhibitory peptide, confirming the synergism between them. The composite microcapsules can not only reduce blood pressure by regulating the renin-angiotensin system but also significantly reduce the degree of cardiac and thoracic aorta fibrosis in SHR, thereby improving organ damage caused by hypertension
Development of Catalytic Combustion and CO\u3csub\u3e2\u3c/sub\u3e Capture and Conversion Technology
Changes are needed to improve the efficiency and lower the CO2 emissions of traditional coal-fired power generation, which is the main source of global CO2 emissions. The integrated gasification fuel cell (IGFC) process, which combines coal gasification and high-temperature fuel cells, was proposed in 2017 to improve the efficiency of coal-based power generation and reduce CO2 emissions. Supported by the National Key R&D Program of China, the IGFC for nearzero CO2 emissions program was enacted with the goal of achieving near-zero CO2 emissions based on (1) catalytic combustion of the flue gas from solid oxide fuel cell (SOFC) stacks and (2) CO2 conversion using solid oxide electrolysis cells (SOECs). In this work, we investigated a kW-level catalytic combustion burner and SOEC stack, evaluated the electrochemical performance of the SOEC stack in H2O electrolysis and H2O/CO2 co-electrolysis, and established a multiscale and multi-physical coupling simulation model of SOFCs and SOECs. The process developed in this work paves the way for the demonstration and deployment of IGFC technology in the future
Efficient Anti-Fog and Anti-Reflection Functions of the Bio-Inspired, Hierarchically-Architectured Surfaces of Multiscale Columnar Structures
Today, in the fields of optical precision instruments, medical devices, and automotive engineering, the demand for anti-reflection and anti-fog surfaces is growing rapidly. However, the anti-fog function often compromises the efficiency of the anti-reflection function. Therefore, optical precision instruments are always restricted by the inability to combine high anti-reflection efficiency and excellent anti-fog performance into one material. In addition, the synergistic mechanism of harmonizing anti-fogging and anti-reflection is currently unclear, which has a negative impact on the development and optimization of multifunctional surfaces. Herein, bio-inspired anti-fogging and anti-reflection surfaces (BFRSs) possessing multiscale hierarchical columnar structures (MHCS) were obtained using a brief and effective preparation technique, combining the biotemplating method and sol-gel method. Specifically, condensed fog droplets distributed on the BFRS can be absolutely removed within 6 s. In addition, the BFRSs endow the glass substrate with a relatively higher reflectance (17%) than flat glass surfaces (41%). Furthermore, we demonstrated the synergistic mechanism of the anti-fogging and anti-reflection functions of BFRSs. On the one hand, the high transparency benefits from the multiple refraction and scattering of light in the MHCS array. On the other hand, the excellent anti-fogging performance is attributed to the imbalance of the capillary force of the MHCS acting on the liquid film. The explanation for these two mechanisms provides more possibilities for the subsequent preparation of multifunctional surfaces. At the same time, the bionic research concept provides new solutions for the researcher to conquer the combination of high transmission and anti-fog properties for precision optical surfaces
Multifunctional Biomimetic Composite Coating with Antireflection, Self-Cleaning and Mechanical Stability
Antireflective and self-cleaning coatings have attracted increasing attention in the last few years due to their promising and wider applications such as stealth, display devices, sensing, and other fields. However, existing antireflective and self-cleaning functional material are facing problems such as difficult performance optimization, poor mechanical stability, and poor environmental adaptability. Limitations in design strategies have severely restricted coatings’ further development and application. Fabrication of high-performance antireflection and self-cleaning coatings with satisfactory mechanical stability remain a key challenge. Inspired by the self-cleaning performance of nano-/micro-composite structure on natural lotus leaves, SiO2/PDMS/matte polyurethane biomimetic composite coating (BCC) was prepared by nano-polymerization spraying technology. The BCC reduced the average reflectivity of the aluminum alloy substrate surface from 60% to 10%, and the water contact angle (CA) was 156.32 ± 0.58°, illustrating the antireflective and self-cleaning performance of the surface was significantly improved. At the same time, the coating was able to withstand 44 abrasion tests, 230 tape stripping tests, and 210 scraping tests. After the test, the coating still showed satisfactory antireflective and self-cleaning properties, indicating its remarkable mechanical stability. In addition, the coating also displayed excellent acid resistance, which has important value in aerospace, optoelectronics, industrial anti-corrosion, etc