• Carbon letters
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• v.6 no.1
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• pp.25-30
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• 2005

The electrosorption of U(VI) from waste water was carried out by using an activated carbon fiber (ACF) felt electrode in a continuous electrosorption cell. In order to enhance the electrosorption capacity at a lower potential, the ACF was electrochemically modified in an acidic and a basic solution. Pore structure and functional groups of the electrochemically modified ACF were examined, and the effects of the modification conditions were studied for the adsorption of U(VI). Specific surface area of all the ACFs was decreased by this modification. The amount of the acidic functional groups decreased with a basic modification, while the amount increased a lot with an acidic modification. The electrosorption capacity of U(VI) decreased on the acid modified electrode due to the shielding effect of the acidic functional groups. The base modified electrode enhanced the capacity due to a reduction of the acidic functional groups. The electrosorption amount of U(VI) on the base modified electrode at .0.3 V corresponds to that of the as-received ACF electrode at .0.9 V. Such a good adsorption capacity was due to a reduction of the shielding effect and an increase of the hydroxyl ions in the electric double layer on the ACF surface by the application of negative potential.

• Carbon letters
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• v.4 no.1
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• pp.31-35
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• 2003

The specific adsorption behaviors of activated carbons (ACs) treated with 30 wt% $H_3PO_4$ or NaOH were investigated in the removals of NO or $NH_3$. The acid and base values were determined by Boehm's titration method. And, the surface properties of ACs were studied by FT-IR and XPS analyses. Also, $N_2/77K$ adsorption isotherm characteristics, including the specific surface area and micropore volume were studied by BET and t-plot methods, respectively. From the adsorption tests of NO and $NH_3$, it was revealed in the case of acidic treatment on ACs that the $NH_3$ removal was more effective due to the increase of acidic functional groups in carbon surfaces. Also, the NO removal was increased, in the case of basic treatment, due to the improvement of basic functional groups, in spite of significant decreases of BET's specific surface area and total pore volume. It was found that the adsorption capacity of ACs was not only determined by the textural characteristics but also correlated with the surface functional groups in the acid-base intermolecular interactions.

• Journal of the East Asian Society of Dietary Life
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• v.25 no.2
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• pp.340-351
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• 2015

To investigate male office workers' dietary habits and their perception and intake of health functional foods, 234 male employees were surveyed by questionnaire. The results were categorized into three age groups: under 35 years, 35 and 45 years, and over 45 years. The over 45 years group had significantly better dietary habits than the others (p<0.05). The most common reason for skipping breakfast was lack of time. Frequency of drinking alcohol was higher in the older group, where tiredness after drinking was lower in the younger group. The perception score of health functional foods was highest in the over 45 years group. Perception of health functional foods was more positive as the age of the groups increased (p<0.01). The number of health functional foods consumed, duration of intake, and beneficial health effects were higher in older groups. Although older people are more concerned about health than relatively younger people, they did not necessarily have reduced the amounts of smoking and drinking. Instead, they simply showed higher intakes of health functional foods to prevent and cure disease and improve their health. Therefore, older people need to receive education about their dietary and living habits instead of simply eating health functional foods. It is necessary to provide correct information about health functional foods by nutritional education.

• Journal of Environmental Science International
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• v.27 no.6
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• pp.383-399
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• 2018

In the present study, the community distribution, functional feeding groups, and habitat groups of the benthic macroinvertebrates from Gayasan National Park were investigated at eight different sites from 2015 to 2016. The correlation between habitat altitude and each group type was analyzed statistically. Biodiversity indices, including dominance, diversity, richness, and evenness indices, were calculated. The results showed a total of 4,216 individual benthic macroinvertebrates were collected, including 4 phyla, 6 classes, 16 orders, 40 families, and 100 species. Gammarus sobaegensis was dominant with 0.141% dominance, and the subdominant species was Epeorus nipponicus with 0.088% dominance. The EPT group(Ephemeroptera, Plecoptera and Tricoptera) accounted for 71.00% of the total species and 67.69% of the total individuals. The number of scraper species was highest, and the number of gathering collector individuals was highest among functional feeding groups. The individual number of scrapers(r=-0.358, p < 0.05) and gathering collectors(r=-0.343, p < 0.05) decreased with increasing altitude. The numbers of species and individuals of clingers and sprawlers were highest among the habitat groups. The individual number of clingers(r=-0.547, p < 0.01) and burrowers(r=-0.331, p < 0.05) significantly decreased with increasing altitude. The diversity and richness indices were higher in St. 3 than in the other sites. The dominance index was highest in St. 2, and the evenness index was highest in St. 7. We evaluated the biological water quality with several known methods, and concluded that ESB(Ecological score of benthic macrovertebrates community) and GPI(Group polution index) were more suitable than KSI(Korean saprobic index) and BMI (Benthic macrovertebrate index) to assess the biological water quality of Gayasan mountain stream water.

• Macromolecular Research
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• v.11 no.4
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• pp.236-240
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• 2003

Fabrication of a graded index profile was possible via photochemical reaction of cinnamoyl groups with 350 nm wavelength UV light to form crosslinked structures. Such structural change may induce the change in the refractive index. In order to generate graded index profile in the PMMA polymer optical fiber (POF) with cinnamoyl groups by photochemistry, a methyl methacrylate monomer containing a cinnamoyl functional group in the side chain were prepared. This monomer was then copolymerized with methyl methacrylate with various compositions not only to utilize advantages of poly(methyl methacrylate) but also to overcome the drawbacks of the cinnamate homopolymer. Changes of refractive indices were investigated with various contents of cinnamoyl group and varying irradiation time. Large change in the refractive index (${\Delta}{\approx}0.01$) and its proper profile shape ($g{\approx}2.2$) can be obtained by changing irradiation time.

• Journal of International Academy of Physical Therapy Research
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• v.12 no.2
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• pp.2323-2330
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• 2021

Background: Stroke patients have weak trunk muscle strength due to brain injury, so a single type of exercise is advised for restoring functionality. However, even after intervention, the problem still lies and it is suggested that another intervention method should be applied with exercise in order to deal with such problem. Objectives: To Investigate the effect of bridge exercise combined with functional electrical stimulation (FES) on trunk muscle activity and balance in stroke patients. Design: Randomized controlled trial. Methods: From July to August 2020, twenty stroke patients was sampled, ten patients who mediated bridge exercises combined with functional electrical stimulation were assigned to experiment group I, and ten patients who mediated general bridge exercises were assigned to experiment groupII. For the pre-test, using surface EMG were measured paralyzed rectus abdominis, erector spinae, transverse abdominis/internal oblique muscle activity, and using trunk impairment scale were measured balance. In order to find out immediate effect after intervention, post-test was measured immediately same way pre-test. Results: Change in balance didn't show significant difference within and between groups, but muscle activity of trunk was significant difference rectus abdominis and erector spinae within groups I (P<.01), also between groups was significant difference (P<.05). Conclusion: Bridge exercise combined with FES could improve trunk function more effectively than general bridge exercise due to physiological effect of functional electrical stimulation.

• Journal of the Korean institute of surface engineering
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• v.54 no.4
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• pp.164-170
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• 2021

Vanadium redox flow batteries (VRFB) have emerged as large-scale energy storage systems (ESS) due to their advantages such as low cross-contamination, long life, and flexible design. However, Hydrogen evolution reaction (HER) in the negative half-cell causes a harmful influence on the performance of the VRFB by consuming current. Moreover, HER hinders V²⁺/V³⁺ redox reaction between electrode and electrolyte by forming a bubble. To address the HER problem, carbon nanotube/graphite felt electrode (CNT/GF) with oxygen functional groups was synthesized through the hydrothermal method in the H₂SO₄ + HNO₃ (3:1) mixed acid solution. These oxygen functional groups on the CNT/GF succeed in suppressing the HER and improving charge transfer for V²⁺/V³⁺ redox reaction. As a result, the oxygen functional group applied electrode exhibited a low overpotential of 0.395 V for V²⁺/V³⁺ redox reaction. Hence, this work could offer a new strategy to design and synthesize effective electrodes for HER suppression and improving the energy density of VRFB.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.222.1-222.1
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• 2015

Recently, graphene quantum dots (GQDs) have attracted great attention due to various properties including cost-effectiveness of synthesis, low toxicity, and high photostability. Nevertheless, the origins of photoluminescence (PL) from GQDs are unclear because of extrinsic states of the impurities, disorder structures, and oxygen-functional groups. Therefore, to utilize GQDs in various applications, their optical properties generated from the extrinsic states should be understood. In this work, we have focused on the effect of oxygen-functional groups in PL of the GQDs. The GQDs with nanoscale and single layer are synthesized by employing graphite nanoparticles (GNPs) with 4 nm. The series of GQDs with different amount of oxygen-functional groups were prepared by the chain of chemical oxidation and reduction process. The fabrication of a series of graphene oxide QDs (GOQDs) with different amounts of oxygen-contents is first reported by a direct oxidation route of GNPs. In addition, for preparing a series of reduced GOQDs (rGOQDs), we employed the conventional chemical reduction to GOQDs solution and controlled the amount of reduction agents. The GOQDs and rGOQDs showed irreversible PL properties even though both routes have similar amount of oxyen-functional groups. In the case of a series of GOQDs, the PL spectrum was clearly redshifted into blue and green-yellowish color. On the other hand, the PL spectrum of rGOQDs did not change significantly. By various optical measurement such as the PL excitation, UV-vis absorbance, and time-resolved PL, we could verify that their PL mechanisms of GOQDs and rGOQDs are closely associated with different atomic structures formed by chemical oxidation and reduction. Our study provides an important insights for understanding the optical properties of GQDs affected by oxygen-functional groups. [1]

• Korean Journal of Food Science and Technology
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• v.22 no.5
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• pp.596-601
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• 1990

The effects of peroxidized lipid on the protein in the biological system of rice bran was studied by determining the changes in the content of functional groups under two different storage conditions. One stored at controlled atmosphere of $35^{\circ}C$ with relative humidity 65% and the other one was exposed to the air of $25^{\circ}-30^{\circ}C$ with relative humidity 70-90%. The lipid peroxidation started after the lipolysis was almost completed. The autoxidation occurred much faster in the bran exposed to the air than that stored in the controlled atmosphere. Substantial changes in the physiochemical characteristics were observed in all of the major functional groups in both of the samples. The content of sulfhydryl and available lysine decrease·1 as lipid peroxidation progressed. Protease activity was lost almost completely. Protein solubility and in vitro digestibility also decreased during storage. The lipid peroxidation and contents of major protein functional groups were significantly correlated (p<0.05) and the correlation coefficients were higher than -0.8, for the both of the sample. peroxidized lipid was found to deteriorate protein in the biological system as well.

• Journal of Korean Medicine Rehabilitation
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• v.18 no.1
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• pp.111-123
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• 2008

Objectives : The objective of this study was to investigate the outcomes of functional electrical stimulation (FES) which was applied twice a day in patients with dysphagia after stroke. Methods : Eleven patients with dysphagia after stroke were participated. The electrical stimulator with two channels was employed for forty minutes daily or forty minutes twice a day for fifteen days. Participants were divided into two groups by random method; The FES was performed twice a day for Twice-FES group (n=6), and once a day for Standard-FES group (n=5). For evaluation of dysphagia, the functional dysphagia scale by videofluoroscopic swallowing study, and swallow function scoring system by six clinical swallowing stage were assessed at pre- and post-treatment. Results : In both groups, there was a significant decrease of total functional dysphagia scales after FES treatment (p<0.05) and the results mainly affected the pharyngeal phase of deglutition. There was no significant difference between the two groups in total functional dysphagia scales, but the Twice-FES group had a decreased residue in oral cavity compared to the standard FES group. In both groups, there were significant improvements in swallow function scoring system (p<0.05). The twice-FES group had more high clinical swallowing stages. Conclusions : The results demonstrated that FES is a clinically effective intervention in treatment of stroke patients with dysphagia. Moreover, the treatment applied twice a day had relatively positive effects on the reduction of oral cavity residue and the improvement of clinical swallowing stage.