• Title/Summary/Keyword: Activation condition

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Manufacturing Process Improvement of Electrode for PEMFC (공정 효율 향상을 위한 연료전지전극 개발)

  • PARK, SEOK JUNG;LEE, JAE SEUNG;LEE, KI SUB;ROH, BUM WOOK
    • Transactions of the Korean hydrogen and new energy society
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    • v.26 no.6
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    • pp.547-553
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    • 2015
  • For commercialization of fuel cell electric vehicles, one of the key objectives is to reduce cost of full stack assembly. Regarding Membrane Electrode Assembly, the major issue is to improve fuel cell activation process in the initial Hydrogen Oxidation Reaction and Oxygen Reduction Reaction. In this research, the VD (Vacuum Drying) process has been developed for improvement of activation process. The VD condition is developed by controlling the temperature and degree of vacuum to remove the remaining solvent of electrode. Consequently, the electrode applied to VD process showed the low characteristics such as 3.5% of remaining solvent content and the improved efficiency such as 15% of activation process speed.

A Study on the Alkali Hydrolysis of PET fabric with Ultrasonic Application(I) - Decomposition Rate Constant and Activation Energy - (초음파를 적용한 PET 직물의 알칼리 가수분해에 관한 연구(I) - 분해속도상수와 활성화 에너지-)

  • 서말용;조호현;김삼수;전재우;이승구
    • Textile Coloration and Finishing
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    • v.14 no.4
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    • pp.214-222
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    • 2002
  • In order to give a silk-like touch to PET fabrics, the PET fabrics were treated with NaOH alkaline solution in various conditions. In alkaline treatment, the liquor flow type pilot weight reduction apparatus with magnetostrictive ultrasonic transducer was used for the study. The weight loss of PET fabrics hydrolyzed in 4% and 6% NaOH solution, at $95^\circ{C}$ and $99^\circ{C}$ for 60min. with ultrasonic application showed 3.7~4.6% higher than that of treated fabric without ultrasonic application. From the difference of specific weight loss, the treatment condition of the maximum of hydrolyzation effect appeared at $95^\circ{C}$ in $4^\circ{C}$ and at $90^\circ{C}$ in 6% NaOH solution, respectively. During the alkali hydrolysis of PET fabrics, the decomposition rate constant(k) increased exponentially with the treatment temperature and were not related with ultrasonic cavitation. The activation energy$(E_a)$ in decomposition of PET fabrics were 21.06kcal/mol with ultrasonic application and 21.10kcal/mol without ultrasonic application. The ultrasonic application gave a little higher value of the activation entropy$(\Delta{S}^\neq)$ and a little lower value of Gibbs free energy$(\Delta{S}^\neq)$ compared with not used ultrasonic apparatus.

Adsorption Characteristic of Endo I and Exo II Purified from Cellulase by Trichoderma viride on Celluloses with Different Crystallinity (결정성이 다른 셀룰로오스에 대한 Trichoderma viride속 Cellulase로부터 분리한 Endo I 및 II의 흡착특성)

  • 김동원;홍영관;장영훈;이재국
    • KSBB Journal
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    • v.13 no.2
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    • pp.162-167
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    • 1998
  • The adsorption behaviors of two major cellulase components, endo I and exo II, from Trichoderma viride were investigated using $\alpha$-celluloses with different correlation crystallinity index(Cc) as substrates. The adsorption of cellulase enzyme components was significantly affected by the reaction condition and the physicochemical properties of the cellulose. The $\alpha$-cellulose was hydrolyzed in the presence of cellulase for various periods. The correlation crystallinity index of $\alpha$-cellulose increased with increasing the hydrolysis time. The adsorption was apparently found to obey the first-order kinetics, and the adsorption activation energy(Ea) was calculated from the adsorption rate constant(ka). The value of adsorption rate constant for endo I was larger than that of exo II. This means that endo I are adsorbed more rapidly than exo II. With the increase in correlation crystallinity index, the values of the adsorption rate constants for endo I and exo II decreased, respectively. The activation energy for the adsorption of exo II on the cellulose also was larger than that of endo I. Also adsorption activation energy of endo I and exo II increased with an increase in the crystallinity of sample cellulose.

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Prefrontal Cortex Activation during Diaphragmatic Breathing in Women with Fibromyalgia: An fNIRS Case Report

  • Hyunjoong Kim;Jihye Jung;Seungwon Lee
    • Physical Therapy Rehabilitation Science
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    • v.12 no.3
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    • pp.334-339
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    • 2023
  • Objective: The present study is designed to delve deeper into the realm of fibromyalgia (FM) symptom management by investigating the effects of diaphragmatic breathing on the prefrontal cortex (PFC) in women diagnosed with FM. Using functional near-infrared spectroscopy (fNIRS), the study aims to capture real-time PFC activation patterns during the practice of diaphragmatic breathing. The overarching objective is to identify and understand the underlying neural mechanisms that may contribute to the observed clinical benefits of this relaxation technique. Design: A case report Methods: To achieve this, a twofold approach was adopted: First, the patient's breathing patterns were meticulously examined to detect any aberrations. Following this, fNIRS was employed, focusing on the activation dynamics within the PFC. Results: Our examination unveiled a notable breathing pattern disorder inherent to the FM patient. More intriguingly, the fNIRS analysis offered compelling insights: the ventrolateral prefrontal cortex (VLPFC) displayed increased activation. In stark contrast, regions of the anterior prefrontal cortex (aPFC) and orbitofrontal cortex (OFC) manifested decreased activity, especially when benchmarked against typical activations seen in healthy adults. Conclusions: These findings, derived from a nuanced examination of FM, underscore the condition's multifaceted nature. They highlight the imperative to look beyond conventional symptomatology and appreciate the profound neurological and physiological intricacies that define FM.

Influence of Supplementary Verbal Encouragement According to the Gender on Abdominal Muscle Activation during Crunch Exercise in Healthy Subjects: A Cross-Sectional Pilot Study (크런치 운동 시 성별에 따른 부수적인 청각적 격려 적용이 정상인의 복부 근육 활성도에 미치는 영향: 단면 예비 연구)

  • Kim, Chang-Yong;Lee, Ji-Hyeon;Kang, Jeong-Hyeon;Kim, Hyeong-Dong
    • Journal of the Korean Society of Physical Medicine
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    • v.12 no.1
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    • pp.15-24
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    • 2017
  • PURPOSE: The purpose of this study was to investigate the effects of supplementary verbal encouragement according to the gender on the activation of abdominal muscles during performance of crunch exercise in healthy subjects. METHODS: A Total of 32 healthy subjects (15 male and 17 female) were randomly allocated to two conditions, crunch exercise with Ki-hap and verbal encouragement with same gender (CKVS) and crunch exercise with Ki-hap and verbal encouragement with different gender (CKVD). The interventions were conducted over three trials in each condition, and measurements were performed on each subject by one examiner in three trials. The activation of rectus abdominis, external oblique, internal oblique, and transverse abdominis muscles were evaluated using electromyography (EMG) during performance of crunch exercise with Ki-hap and verbal encouragement with same gender or different gender, respectively. RESULTS: The results showed that there were no significantly difference in the activation of all abdominal muscles in those of the CKVS compared with the CKVD (p>.05). The results also showed that there were no significantly difference in the ratio of muscle activation at global muscle to that at local muscle between two conditions (p>.05). CONCLUSION: These findings demonstrated that application of the supplementary verbal encouragement by gender does not affect to activate the abdominal muscles of subject to perform a movement, at the same time, it would suggest positive evidence for improving activation of abdominal muscles.

Effect of Applied Pressure Differences to Abdomen on Lumbar and Abdominal Muscle Activation During Upper Limb Exercise (상지운동 동안 복부에 적용된 압력 차이가 요부와 복부 근육 활성도에 미치는 영향)

  • Ko, Eun-Hye;Yoon, Hye-Sun;Cynn, Heon-Seock;Lee, Kang-Sung
    • Journal of Korean Physical Therapy Science
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    • v.10 no.2
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    • pp.96-103
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    • 2003
  • The purpose of this study was to assess the effect of applied pressure to abdomen on lumbar and abdominal muscle activation during upper limb exercise. The experimental group consisted of twenty-seven healthy male subjects (mean age=$22.40{\pm}2.19years$, mean height=$175.30{\pm}2.19cm$, mean weight= $67.67{\pm}7.44kg$, RM=$8.43{\pm}2.76kg$). In each different pressure condition (OmmHg, 30mmHg, 70mmHg, 100mmHg), upper limb exercise was performed in total of 10 trials with 10 RM dumb-bell exercise. Lumbar and abdominal muscle activity was measured using surface bipolar electrode electromyography(EMG). EMG activity was measured from upper rectus abdominis, external oblique abdominis, internal oblique abdominis, and elector spinae. The raw EMG signal was processed into the root mean square(RMS). All RMS EMG data were normalized and express as a percentage of the EMG(%EMG). Collected data were statistically analyzed by SPSS/PC Ver 10.0 using two-way analysis of variance for repeated measures($4{\pm}3$) and Bonferroni post hoc, test. Lumbar and abdominal muscle activation was significantly increased when 100 mmHg was applied(p<.05). Upper rectus abdominis activation was significantly increased compared as other muscles activation(p<.05). However, there were no interaction between pressure and muscles(p>.05). The findings of this study can be used as a fundamental data when lumbar orthosis is applied and external pressure can be used as a therapeutic tool.

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Neural bases underlying Native or Foreign word production, and Language switching (모국어와 외국어의 단어산출 및 언어 간 전환에 따른 뇌 활성화 과정)

  • Kim, Choong-Myung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.3
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    • pp.1707-1714
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    • 2015
  • The neural bases underlying within or between-language picture naming was investigated by using event-related fMRI. The present suudy explorered the following two goals: The first is to compare cortical activation areas relevant to naming process in native and foreign language, and to decide whether the activation pattern of the foreign word will be the same as native words or not. The next is to find the cerebral areas involved only in alternating language switching between native and foreign language condition. Differential activation patterns were observed for language switching against one-language. Both naming tasks all activated the left inferior frontal gyrus (LIFG) as expected. However the differences in naming between languages were reflected in the activation amount of the LIFG, namely more activation in naming the native language than the foreign language. Especially, naming of the foreign word from English showed the similar area and size in activation with native language suggesting that the process of borrowed noun resembles that of native common noun. And the language switching between languages newly activated the right middle frontal gyrus as well as the left inferior frontal areas. The right middle frontal gyrus engagement in switching conditions obviously identified that right hemisphere is recruited in code switching possibly with respect to meta-cognition controlling language index at a subconscious level.

The Effects of Proprioceptive Neuromuscular Facilitation Leg Patterns on the Muscle Activation of Neck Flexors (고유수용성신경근촉진법 중 하지패턴이 경부 굴곡근 근활성도에 미치는 영향)

  • Lee, Moon-Kyu;Kim, Jong-Man;Park, Hyung-Ki;Kim, Won-Ho
    • Physical Therapy Korea
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    • v.15 no.1
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    • pp.46-53
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    • 2008
  • The aim of the present study was to determine the effect of proprioceptive neuromuscular facilitation (PNF) leg patterns on the muscle activation of neck flexors. Twenty healthy subjects participated in this study. Each subject performed bilateral asymmetrical PNF leg patterns against manual resistance under four conditions: through the full range of motion toward the right side, left side, and the end range in the right side, left side. Electromyographic (EMG) data was collected from the sternocleidomastoid (SCM) muscles as neck flexors. The root mean square (RMS) value of the SCM was measured and normalized from maximal EMG activity of the SCM. The data were analyzed using the paired t-test and repeated analysis of variance (ANOV A) was used to compare the statistical significance. The results of this study are summarized as follows: Firstly, the RMS values of SCM were significantly higher in all four PNF leg patterns than in the resting condition (p<.05). Secondly, there was no significant difference in muscle activation according to the direction of PNF leg patterns (p>.05). Thirdly, there was no significant difference in muscle activation according to the point of range of the motion of leg patterns (p>.05). It is suggested that PNF bilateral asymmetrical leg patterns have a considerable effect on muscle activation of the SCM, regardless of the range of motion and direction of PNF bilateral asymmetrical leg patterns.

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Role of Protein Kinases on NE-$_{\kappa}B$ Activation and Cell Death in Bovine Cerebral Endothelial Cells

  • Ahn, Young-Soo;Kim, Chul-Hoon;Kim, Joo-Hee
    • The Korean Journal of Physiology and Pharmacology
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    • v.3 no.1
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    • pp.11-18
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    • 1999
  • Nuclear factor $_{\kappa}B\;(NF-_{\kappa}B)$ activation is modulated by various protein kinases. Activation of $NF-_{\kappa}B$ is known to be important in the regulation of cell viability. The present study investigated the effect of inhibitors of protein tyrosine kinase (PTK), protein kinase C (PKC) and protein kinase A (PKA) on $NF-_{\kappa}B$ activity and the viability of bovine cerebral endothelial cells (BCECs). In serum-deprivation-induced BCEC death, low doses of $TNF{\alpha}$ showed a protective effect. $TNF{\alpha}$ induced $NF-_{\kappa}B$ activation within 4 h in serum-deprivation. PTK inhibitors (herbimycin A and genistein) and PKC inhibitor (calphostin C) prevented $NF-_{\kappa}B$ activation stimulated by $TNF{\alpha}.$ Likewise, these inhibitors prevented the protective effect of $TNF{\alpha}.$ In contrast to $TNF{\alpha}-stimulated\;NF-_{\kappa}B$ activity, basal $NF-_{\kappa}B$ activity of BCECs in media containing serum was suppressed only by calphostin C, but not by herbimycin A. As well BCEC death was also induced only by calphostin C in serum-condition. H 89, a PKA inhibitor, did not affect the basal and $TNF{\alpha}-stimulated\;NF-_{\kappa}B$ activities and the protective effect of $TNF{\alpha}$ on cell death. These data suggest that modulation of $NF-_{\kappa}B$ activation could be a possible mechanism for regulating cell viability by protein kinases in BCECs.

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Preparation of Activated Carbon Screen Using Stainless Steel Mesh and Cellulose Fiber (스테인레스 망과 섬유를 이용한 활성탄소 망의 제조)

  • Shin, Jinhwan;Kim, Taeyoung;Jeoung, Youngdo
    • Journal of the Korean GEO-environmental Society
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    • v.9 no.3
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    • pp.45-50
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    • 2008
  • In this work, stainless steel mesh-supported activated carbons were prepared using phenolic resin and cellulose fiber. $ZnCl_2$ was used as a activation reagent in this work. $ZnCl_2$-chemical activation method has been proposed to produce highly porous activated carbons. The objectives of this work were to develop an optimal condition for manufacturing activated carbon assemblies screen from stainless steel mesh and phenolic resin. The iodine number was more increased over activation temperature of $450^{\circ}C$. Iodine number was 657 mg/g at activation temperature of $550^{\circ}C$, penolic resin concentration 20% and $ZnCl_2$ concentration 15%. Iodine number was 1359.4 mg/g when 10% cellulose added to these conditions.

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