Aqueous Zn-ion batteries (ZIBs) are very attractive owing to their high safety and low cost. Among various cathode materials, organic materials-based electrodes incorporating various redox functional groups have gained significant attention in the field of ZIBs due to their benefits of a tunable structural design, facility, eco-friendly, and possibility of multivalent energy storage. Herein, we demonstrate the nanostructured organic active materials deposited onto the CNT networks (HyPT@ CNT) for flexible ZIBs. This HyPT nanorods were obtained reassemblying the herringbone structured 3,4,9,10-tetracarboxylic dianhydride through a hydrothermal process in the presence of acid. These HyPT@CNT hybrids were electronically conductive and redox active, as well as could be fabricated into a flexible electrode achieving flexibility from mechanical integrity of robust networked structure. The as-fabricated flexible ZIBs delivered the high capacity of 100 Ah g− 1 at a current density of 0.1 A g− 1 and long-term cycling performance exceeding 5000 cycles. Consequently, these electrochemical performances are associated with the redox reactivity of carbonyl groups as verified by spectroscopic and electrochemical characterizations and the hybridization of HyPT nanorods with CNT networks.

Postural stability can reduce the likelihood of critical slip and fall accidents in workplaces. The present study aimed to analyze the effect of shoes type on the ability of postural control during quiet standing. The effect of workload on the body balance was also of primary concern. Thirteen healthy male undergraduate students participated voluntarily in the experimental study. Standing on a force plate with wearing slippers, sports shoes, or safety shoes, two-axis coordinate on subjects’ center of pressures (COP) was obtained in the two levels, rest and workload. For the workload level, subjects performed treadmill exercise to reach the predetermined level of physical workload. By converting the position coordinates of COPs, the postural sway length in both anterior-posterior (AP) axis and medio-lateral (ML) axis was assessed. ANOVA results showed that, in AP direction, wearing slippers significantly increased the postural sway length compared to wearing sports shoes or safety shoes. No significant difference in the mean sway length in AP axis was observed between sports shoes and safety shoes. In ML direction, both the workload and the shoes type did not significantly affect the mean length of postural sway. However, the postural sway length increased marginally with the slippers especially during the workload condition. This study explains wearing slippers may interfere with the ability of postural control during quiet standing. Physical workload decreases the ability of postural stability further.

Postural instability can increase the likelihood of hazardous slip and fall accidents in workplaces. The present study intended to extend understanding of the effect of abnormal neck posture on postural control during quiet standing. The effect of body fatigue on the postural control was also of primary concern. Twelve healthy undergraduate students volunteered to participate in the experiment. Standing on a force platform with the neck neutral, flexed, extended, or rotated, subjects’ center of pressures (COP) were measured under the two levels of body fatigue. For the fatigue condition, Subjects exercised in a treadmill to meet the predetermined level of body fatigue. Analyzing the position coordinates of COPs, the length of postural sway path was assessed in both medio-lateral (ML) axis and anterior-posterior (AP) axis. Results showed that, in AP direction, neck extension or rotation significantly increased the sway length as compared with neck neutral. Neck extension led to greater sway length compared to neck rotation. Neck flexion did not differ from neck neutral. The sway length in the AP direction also became significantly larger as the body fatigue accumulated after treadmill exercise. In ML direction, as compared to neutral posture, the neck extension, flexion, or rotation did not significantly affect the length of postural sway path. However, the sway length seemed to increase marginally with the neck extended during the fatigued condition. This study demonstrates that abnormal neck posture may interfere with postural control during standing. The ability to maintain postural stability decreases significantly with the neck extended or rotated. Body fatigue leads to postural instability further.

Loss of postural stability can possibly lead to slip and fall accidents in the number of workplaces and everyday life. This study was aimed to examine the effects of whole body fatigue and partially limited visual field on the ability of maintaining postural balance during quiet standing. A group of twelve healthy male subjects participated in the experiment. Before and after experiencing the whole body fatigue induced by bicycling exercises, the position coordinates of subject’s center of pressure (COP) were obtained under the two levels of visual field condition (i.e., open visual field and limited visual field). Four levels of the whole body fatigue examined were rest, 300watt, 600watt, and 900watt. Position coordinates of COPs measured on a force plate were then converted into the total length of postural sway path in both the medio-lateral (ML) direction and the anterior-posterior (AP) direction. Two-way ANOVA result showed that the length of sway path in the AP direction became significantly larger as the whole body fatigue accumulated. Post-hoc test revealed statistically significant differences between rest and 900watt and between 300watt and 900watt. The significant increase of the sway length was also found when the visual field was partially obstructed by the boxes. In the ML direction, however, there was no statistically significant difference of the postural sway in both the AP and ML directions. The results imply that the ability of maintaining postural stability can be reduced significantly due to such tasks along with whole body fatigue. The postural balance can also be impaired by the limited visual field.

As a measure of health, the percentage of body fat has been utilized for many ergonomist, physician, athletic trainers, and work physiologists. Underwater weighing procedure for measuring the percentage of body fat is popular and accurate. However, it is relatively expensive, difficult to perform and requires large space. Anthropometric techniques can be utilized to predict the percentage of body fat in the field setting because they are easy to implement and require little space. In this concern, the purpose of this study was to find a regression model to easily predict the percentage of body fat using the anthropometric circumference measurements as predictor variables. In this study, the data for 10 anthropometric circumference measurements for 252 men were analyzed. A full model with ten predictor variables was constructed based on subjective knowledge and literature. The linear regression modeling consists of variable selection and various assumptions regarding the anticipated model. All possible regression models and the assumptions are evaluated using various statistical methods. Based on the evaluation, a reduced model was selected with five predictor variables to predict the percentage of body fat. The model is : % Body Fat = 2.704-0.601 (Neck Circumference) + 0.974 (Abdominal Circumference) -0.332 (Hip Circumference) + 0.409 (Arm Circumference) - 1.618 (Wrist Circumference) + ε. This model can be used to estimate the percentage of body fat using only a tape measure.

Mental fatigue is inevitable in the workplace. Since mental fatigue can lead to decreased efficiency and critical accidents, it is important to manage mental fatigue from the viewpoint of accident prevention. An experiment was performed to evaluate mental fatigue using the formant frequency analysis of human voices. The experimental task was to mentally add or subtract two one-digit numbers. After completing the tasks with four different levels of mental fatigue, subjects were asked to read Korean vowels and their voices were recorded. Five vowel sounds of “아”, “어”, “오”, “우”, and “이” from the voice recorded were then used to extract formant 1 frequency. Results of separate ANOVAs showed significant main effects of mental fatigue on formant 1 frequencies of all five vowels concerned. However, post-hoc comparisons revealed that formant 1 frequencies of “아” and “어” were most sensitive to mental fatigue level employed in this experiment. Formant 1 frequencies of “아” and “어” significantly decrease as the mental fatigue accumulates. The formant frequency extracted from human voice would be potentially applicable for detecting mental fatigue induced during industrial tasks.

Korean railway has run about 110 years since 1989 and played a great role of industrialization in Korea. It is known that rail transport systems have many advantages of being more safe, energy-efficient, and environment-friendly, as compared to other tran

We investigated the effects of trunk twist on postural stability during manually handling flat ties. Ten male subjects participated in this study. While handling 5kgf and 10kgf bundles of flat ties respectively, their centers of pressure (COPs) were measu

In this study, we examined the effects of background and underline on the readability of displayed text The background was placed on every other line and the underline was done with every line of the text The effect of adding color to the background and u

This study was aimed to understand the effects of perturbed floor surface on human postural stability while standing. Ten subjects were asked to stand quietly on the surface with two angles of inclination (0° and 5°), two contamination conditions(dry and

본 연구에서는 왕호장 열매 추출물(FSR)의 항염증 효과를 측정하였다. 왕호장 열매 추출물은 RAW 264.7 macrophage 세포에서 염증 사이토카인(1L-1β, IL-6, TNF-α)의 발현을 억제하였으며, 농도 의존적으로 NO 생성을 억제하고, 그 효과는 100 µg/mL 농도에서 51%로 나타났다. 뿐만 아니라, iNOS와 COX-2의 mRNA와 단백질 발현을 모두 억제함을 확인하였다. 따라서 왕호장 열매 추출물은 항염증 효능을 갖는 화장품 소재로서의 개발 가능성이 클 것으로 기대된다.