This paper gives a bibliographical review of the finite element methods (FEMs) applied to the analysis of ceramics and glass materials. The bibliography at the end of the paper…
Abstract
This paper gives a bibliographical review of the finite element methods (FEMs) applied to the analysis of ceramics and glass materials. The bibliography at the end of the paper contains references to papers, conference proceedings and theses/dissertations on the subject that were published between 1977‐1998. The following topics are included: ceramics – material and mechanical properties in general, ceramic coatings and joining problems, ceramic composites, ferrites, piezoceramics, ceramic tools and machining, material processing simulations, fracture mechanics and damage, applications of ceramic/composites in engineering; glass – material and mechanical properties in general, glass fiber composites, material processing simulations, fracture mechanics and damage, and applications of glasses in engineering.
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Y. Kobayashi, S. Ishida, K. Ihara, Y. Yasuda and T. Morita
This work describes a metal-metal bonding process by the use of Cu nanoparticles as a filler material. The Cu particles used were prepared by reduction of Cu2+ with hydrazine in…
Abstract
This work describes a metal-metal bonding process by the use of Cu nanoparticles as a filler material. The Cu particles used were prepared by reduction of Cu2+ with hydrazine in the presence of cetyltrimethylammonium bromide as a dispersing agent (uncoated Cu particles). Polypyrrole (PPy)-coated Cu nanoparticles were also used as the filler. Strong bonding for Cu discs was not obtained by using the PPy-coated particles. For the uncoated Cu particles, a shear strength required for separating the discs bonded by annealing at 400°C in H2 gas was as large as 18.1 MPa.
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Yukio Tamura, Fumiaki Kobayashi, Osamu Suzuki, Yasushi Uematsu and Yasuo Okuda
Human beings spend their daily lives within the range of the atmospheric boundary layer, where airflow is affected by friction from Earth's surface. The airflow in this area is…
Abstract
Human beings spend their daily lives within the range of the atmospheric boundary layer, where airflow is affected by friction from Earth's surface. The airflow in this area is generally called wind. Strong wind occasionally causes severe damage to infrastructures and people because of its aerodynamic effects, but even weak and moderate winds can have serious environmental impacts on human society such as those seen with air-pollution problems and thermal effects.
Mingjing Jiang, Fang Liu, Huaning Wang and Xinxin Wang
The purpose of this paper is to present an investigation of the effect of different gravity conditions on the penetration mechanism using the two-dimensional Distinct Element…
Abstract
Purpose
The purpose of this paper is to present an investigation of the effect of different gravity conditions on the penetration mechanism using the two-dimensional Distinct Element Method (DEM), which ranges from high gravity used in centrifuge model tests to low gravity incurred by serial parabolic flight, with the aim of efficiently analyzing cone penetration tests on the lunar surface.
Design/methodology/approach
Seven penetration tests were numerically simulated on loose granular ground under different gravity conditions, i.e. one-sixth, one-half, one, five, ten, 15 and 20 terrestrial gravities. The effect of gravity on the mechanisms is examined with aspect to the tip resistance, deformation pattern, displacement paths, stress fields, stress paths, strain and rotation paths, and velocity fields during the penetration process.
Findings
First, under both low and high gravities, the penetration leads to high gradients of the value and direction of stresses in addition to high gradients in the velocity field near the penetrometer. In addition, the soil near the penetrometer undergoes large rotations of the principal stresses. Second, high gravity leads to a larger rotation of principal stresses and more downward particle motions than low gravity. Third, the tip resistance increases with penetration depth and gravity. Both the maximum (steady) normalized cone tip resistance and the maximum normalized mean (deviatoric) stress can be uniquely expressed by a linear equation in terms of the reciprocal of gravity.
Originality/value
This study investigates the effect of different gravity conditions on penetration mechanisms by using DEM.
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Satomi Fujimori, Suchinda Jarupat Maruo, Toshiaki Watanabe, Naoya Taki, Fumihito Sasamori, Kazuki Kobayashi, Hisaki Akasaki, Masao Okuhara, Ryoji Uchiyama, Kazuki Ashida, Hisaaki Tabuchi and Koji Terasawa
This study aims to establish a Japanese-style healthcare program customized for Japan and Asia under ISO 9001: 2008 (ISO: International Organization for Standardization) to…
Abstract
Purpose
This study aims to establish a Japanese-style healthcare program customized for Japan and Asia under ISO 9001: 2008 (ISO: International Organization for Standardization) to improve problem areas and to inspect the effectiveness of the program. Furthermore, the authors wanted to create this health program using the ISO widely available in Asian countries and make an international contribution.
Design/methodology/approach
The authors implemented a 6- to 10-month health program in Minowa Town, Matsumoto City and Nagano City in Japan. This study assessed findings from pedometric, anthropometric and blood pressure measurements and physical fitness, blood chemistry and brain function tests.
Findings
The comparisons were made by examining the interaction effects between groups of participants. Groups from three regions in Japan showed significant differences on the physical fitness tests; regarding the 10-meter obstacle walk, the results of the Minowa participants showed the greatest improvement and the Matsumoto participants showed the second greatest improvement. In the six-min walk, the time of the Minowa participants significantly improved.
Research limitations/implications
This health education program, which has been conducted by the Japanese authors since 1998, measures anthropometry, brain function and physical fitness and performs blood tests before and after the program and it measures energy consumption with a pedometer during the program. With the aim of improving exercise via encouragement from friends and a sense of community with fellow participants, participants learn together with hands-on training in tai chi and aerobics about the importance of ongoing exercise and proper nutrition. This health education met the Health Education ISO in 2014.
Practical implications
Since 2010, Nagano Prefecture, including Minowa Town, Matsumoto City and Nagano City, where our study was carried out, has been the area with the highest life expectancy rates in Japan.
Social implications
The authors want to make this health promotion through ISO widely available in Asian countries and an international contribution.
Originality/value
This study aimed to appropriately establish a Japanese-style healthcare program under the ISO 9001:2008 to improve problem areas and inspect its effectiveness.
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Rameesh Lakshan Bulathsinghala, Sandun Fernando, Thantirige Sanath Siroshana Jayawardana, Nilanthi Heenkenda, Sajeeva Jeyakumar, Prathees Packiyarasa, Gamage Hemamala and Dhananatha Wijesena
Motorcycle is one of the popular modes of transport in developing countries. However, the statistics related to accidents show that motorcycles are the most vulnerable vehicles…
Abstract
Purpose
Motorcycle is one of the popular modes of transport in developing countries. However, the statistics related to accidents show that motorcycles are the most vulnerable vehicles. Research studies have revealed that half of all the possible types of motorcycle injuries could be reduced or prevented using effective protective clothing. Facts and figures emphasize that this is high time to develop a safety jacket for motorbike riders. This paper aims to develop an innovative, integrated automatic air-inflated tubeless jacket to prevent major injuries in fatal accidents.
Design/methodology/approach
Two accelerometers integrated near the front axle, an angle sensor and the electronic control unit (ECU) were used to detect the collision or accident. The sensors were fixed on the bike and connected with the ECU via a bluetooth device that was always at the activated stage. The fused sensors were emulated with the ECU under laboratory conditions. The trigger signal generated by the crash discriminant algorithm triggered the chemical reaction to generate N2 gas and inflate the tubeless safety jacket.
Findings
Under laboratory conditions, it was found that the signal generated by the ECU unit ejected approximately 15 litres of N2 gas in volume to fill the jacket within 100 milliseconds, which was less than the approximate estimated falling time of the rider 120 milliseconds.
Originality/value
The existing developments of airbag systems in motorbikes are mounted on the motorbikes' frame, following the airbag systems in automobiles. These developments cannot fully protect the rider due to differentiation in crash dynamics and respective positions of the rider at the point of impact. Though few safety jackets and airbag vests are developed, the airbag deployment is activated when rider and motorbike separated during a collision using a tether-triggering mechanism. The authors designed the jacket so that inflation is activated not only by crash sensors but also on the fusion of multiple sensors based on a crash discriminative algorithm. The airbag deployment mechanism is incorporated with the jacket and acts as a safety jacket during a collision.
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Recently, mHealth apps for COVID-19 have emerged as a new research area due to the diverse efforts to control the COVID-19 epidemic. Although there are many bibliometric studies…
Abstract
Purpose
Recently, mHealth apps for COVID-19 have emerged as a new research area due to the diverse efforts to control the COVID-19 epidemic. Although there are many bibliometric studies on mHealth and its applications, no bibliometric study sheds light on mHealth apps for COVID-19 as a new research area. To address the above-mentioned research gap, the current study conducts a bibliometric analysis of research in mHealth apps for COVID-19. It aims to provide a comprehensive overview of the new area and its directions.
Design/methodology/approach
The study uses a bibliometric approach to provide an analysis of the overall status of research in mHealth apps for COVID-19. The Scopus database provided by Elsevier was used to extract the analyzed data in this study. SciVal was used to perform the analyses, while VOSviewer was used for scientific mapping.
Findings
A total of 457 publications were published between 2020 and 2021 (until Tuesday, June 1) and cited 3,559 times. Publications were written by 2,375 authors, with an average of 5.20 authors per publication. Articles play a pivotal role in the literature on mHealth apps for COVID-19 in terms of production and impact. The research area of mHealth apps for COVID-19 is multidisciplinary. The United States made the largest contribution to this area, while the UK was the most influential. This study reveals the most productive and influential sources, institutions and authors. It also reveals the research hotspots and major thematic clusters in mHealth apps for COVID-19, highly cited publications and the international collaboration network.
Originality/value
mHealth apps for COVID-19 are gaining more and more importance due to their influential role in controlling the COVID-19 epidemic. Using bibliometric analysis, the study contributes to defining the knowledge structure of global research in mHealth apps for COVID-19 as a new, interdisciplinary area of research that has not previously been studied. Therefore, the study results and the comprehensive picture obtained about research in mHealth apps for COVID-19, especially at the level of Internet of Things (IoT) and artificial intelligence applications, make it an effective supplement to the expert evaluation in the field.
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Muhammad Ma’ruf, Kanao Fukuda, Shahira Liza and Rizqon Fajar
Developing bio-lubricants for high-temperature applications, such as engine operations, requires reliable thermal stability assessment. This study aims to create a predictive tool…
Abstract
Purpose
Developing bio-lubricants for high-temperature applications, such as engine operations, requires reliable thermal stability assessment. This study aims to create a predictive tool to evaluate thermal stability using existing organic compounds data. The model predicts the onset temperature (T onset) of bio-lubricant candidates derived from epoxidation with various amine nucleophiles, enhancing initial selection efficiency and reducing reliance on traditional trial-and-error methods.
Design/methodology/approach
Using the Python library Mordred, molecular descriptors were calculated from the SMILES structures of 126 compounds with known T onsets. These descriptors were inputs for machine learning models predicting the thermal stability of bio-lubricants. The models were evaluated on training and test data sets and validated with novel synthesized compounds.
Findings
The predictive model showed strong performance on the test data set, with an R² of 0.93 and a root mean square error of 17.77. In external validation, the model estimated the thermal stability of a novel bio-lubricant compound (MA-EPO) at 290.7°C, closely matching the actual T onset of approximately 300°C.
Originality/value
This research introduces a method for predicting the thermal stability of bio-lubricants using machine learning and open-source libraries. This approach significantly advances the field by improving the efficiency of bio-lubricant development for high-temperature applications. It provides a cost-effective and time-saving alternative to traditional experimental methods, serving as a valuable resource for researchers and developers in the bio-lubricant industry.
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Minatsu Kobayashi, Motoki Iwasaki and Shoichiro Tsugane
Developed countries have devised guidelines for various eating habits, many of which simply recommend “eating various foods” without specifying how much food the individual should…
Abstract
Purpose
Developed countries have devised guidelines for various eating habits, many of which simply recommend “eating various foods” without specifying how much food the individual should consume each day. The authors aimed to examine the relationship between the variety of food consumed and the probability of nutritional adequacy in middle‐aged Japanese.
Design/methodology/approach
In total, 215 subjects (102 men and 113 women) provided complete dietary records for seven days in each of the winter, spring, summer and autumn. Subjects were categorized into groups of five according to the amount of each food eaten per day, calculated energy, and nutrients in the food. Results were compared with respective indicators of nutrition defined by the Dietary Reference Intakes for Japanese (2010).
Findings
The percentage of overweight subjects was higher in the group that did not consume a wide variety of foods. Intake of energy, calcium, zinc, magnesium, vitamins B1, B2 and C were insufficient in the subjects who did not consume a wide variety of foods. Although a trend toward sufficient nutrient intake was observed in the group that consumed a variety of foods, the estimated average requirement for several nutrients such as calcium and zinc was below accepted standards for good nutrition.
Originality/value
The variety of foods eaten is related to the adequacy of intake levels of certain nutrients and to body mass index in middle‐aged Japanese subjects. Eating a wide variety of foods is important to ensuring adequate nutrient intake.
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Akizumi Tsutsumi, Natsu Sasaki, Yu Komase, Kazuhiro Watanabe, Akiomi Inoue, Kotaro Imamura and Norito Kawakami
The purpose of this paper is to conduct a comprehensive review on the implementation and the effect of Japan's Stress Check Program, a national program to monitor and control…
Abstract
Purpose
The purpose of this paper is to conduct a comprehensive review on the implementation and the effect of Japan's Stress Check Program, a national program to monitor and control workplace psychosocial factors that was initiated in December 2015.
Design/methodology/approach
We comprehensively reviewed articles published in Japanese and English, assessed the performance of the Stress Check Program and summarized future challenges. We also discussed the implications for practice.
Findings
The available literature presented a scientific basis for the efficiency and validity of predictions using the Brief Job Stress Questionnaire, which is the instrument recommended to screen workers with high stress in the program. No study has verified the effect of the program on workers' mental health by using group analysis of stress check results. There is room for improvement in tools that contribute to identifying workers with high stress and in measures for improving the work environment. The Stress Check Program contrasts with risk management of psychosocial factors at work, widely adopted in European countries as a strategy for improving workers' mental health by focussing on the psychosocial work environment.
Practical implications
Although the effectiveness of the Japanese program needs further evaluation, future developments of the program would provide insight for national policies on psychosocial risks/psychosocial stress at work.
Originality/value
This paper is the first systematic review on the implementation and effects of Japan's Stress Check Program.