• Korean Chemical Engineering Research
• /
• v.51 no.3
• /
• pp.388-393
• /
• 2013

The study was focused to evaluate the possibility for combination membrane of bacterial cellulose (BC) and graphene with high electrical properties. BC with natural polymer matrix was known to have strong physical strength. For the combination of graphene with BC, the surface of graphene was modified with oxygen plasma by changing strength and time of radio waves in room temperature. Water contact angle of modified graphene grew smaller from $130^{\circ}$ to $12^{\circ}$. XPS analysis showed that oxygen content after treatment increased from 2.99 to 10.98%. Damage degree of graphene was examined from $I_D/I_G$ ratio of Raman analysis. $I_D/I_G$ ratio of non-treated graphene (NTG) was 0.11, and 0.36 to 0.43 in plasma treated graphene (PTG), increasing structural defects of PTG. XRD analysis of PTG membrane with BC was $2{\theta}$ same to BC only, indicating chemically combined membrane. In FT-IR analysis, 1,000 to 1,300 $cm^{-1}$ (C=O) peak indicating oxygen radicals in PTG membrane had formed was larger than NTG membrane. The results suggest that BC as an alternation of plastic material for graphene combination has a possibility in some degree on the part like transparent conductive films.

• Journal of Conservation Science
• /
• v.31 no.1
• /
• pp.1-11
• /
• 2015

Seated Amitabha Triad at Muwisa Temple (Treasure No. 1312) had been known as wooden Buddha statue, but a precise safety inspection revealed that the statue is terracotta Buddha statue made with clay. The clay layer of Amitabha Triad was conserved due to its severe damage. In this study, experiments were conducted to produce the most appropriate filler for the conservation treatment of the seated Amitabha Triad. Mixed clay samples with various ratios were produced and surface hardening state, crack, color change, and shrinkage of the samples during dry process were measured. Loess, fine sand powder, and cotton were used to produce the mixed clay for the filler with six different ratios and then 12 different concentration glues made with glutinous rice glue, Pachymeniopsis Elliptica glue, and animal glue were added as adhesives. Total 72 types of samples were prepared and comparative study was conducted. As a result, when the mixed clay contains 2.5% cotton compared to the weight per cent of loess and fine sand powder and also loess and fine sand in the mixed clay have a 15:1 ratio, the mixed clay had the lowest shrinkage. Animal glue is considered as an appropriate glue since it had small color change, low physical property change and shringkage. Therefore, mixed clay (loess:fine sand=15:1) mixed with 15ml animal glue is likely to be a suitable filler for conservation treatment of the seated amitabha triad at the Muwisa Temple.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.20 no.6
• /
• pp.1678-1727
• /
• 2006

This study was perfromed to develop the assessment guideline and endpoints for clinical trial with anticancer herbal medicine. The botanical products used to humans for long time may be applied to phase 3 clinical trial after submitting the evidences for safety and efficacy of them or completion of basic requirement of phase 1 and phase 2 for safety confirmation and dose determination. Syndrome improvement was chiefly evaluated by Zubrod and karnofsky(%) methods. We suggest the general clinical trial assessment with botanical products, by following assessment points, that is, tumor size for 50 points, survival fate for 10 points, major syndromes for 40 points. It is recommendable that the each symptom of Qi deficiency syndrome, blood deficiency syndrome and Qi stagnation syndrome was allocated by assessment points, Similarly, the each symptom was given the assessment points according to the severity of symptom, for example, slight for 3 points, moderate for 2 points and severe for 1 point in hepatocelluar carcinoma and lung cancer. Then, the efficacy of botanical products was evaluated by the difference between pre-treatment and post-treatment. Asking the neoplastic patients of questionnaire on physical, emotional, cognitive, social and role subjects availability, three more syndromes (Fatigue, Pain and Nausea/Vomit), quality of life(QOL) will be evaluated by GLM statistics. In addition, in case of lung cancer, 13 questions will be asked by the EORTC QLQ-C13 forms. As the assessment of endpoints for efficacy to reduce side effects induced by chemotherapy and radiotherapy, the data of image scanning and hemato-urinalysis can be usefully applied on immune response, weight loss, indigestion, hemopoietic damage and injury of liver and kidney, while the changes of syndromes of side effect can be evaluated by differentiation methods of Qi and blood and five viscera. However, it is still necessary to determine the ratio between scientific analytical method and Oriental differentiation method as well as confirm the Oriental assessment endpoints by clinical trial. In addition, we suggest the continuous development of assessment endpoints on other carcinomas except of hepatocelluar carcinoma and lung cancer in future.

• Applied Chemistry for Engineering
• /
• v.30 no.5
• /
• pp.556-561
• /
• 2019

In this study, the physical and chemical analyses of petroleum residues (pyrolized fuel oil, PFO) were conducted and major components were selected to investigate their fire and explosion characteristics. Major component distribution areas of the PFO were identified via the GC-SIMDIS and MALDI-TOF analyses. In addition, the qualitative analysis of major component distribution areas was performed by GC-MS analysis. Major components of pyrolysis residue were selected based on the results of various analyses such as EA, SARA and TGA. As a result, benzene, toluene and xylene were selected as major components. Finally, the process hazard analysis software tool (PHAST) analysis was performed to investigate the range of maximum damage effect in case of fire and explosion. Toluene presented the highest risk due to the radiation effect of $227kW/m^2$ and 118 m in the case of jet fire. Xylene and benzene showed the maximum radiant heat values of 114 and $151kW/m^2$, respectively. It was also confirmed from the analysis of pasquill stability and wind speed that the radiant heat increased up to 55% according to wind speed in benzene, which was considered to be a main factor increasing the influence range.

• Food Science and Preservation
• /
• v.15 no.5
• /
• pp.630-634
• /
• 2008

The effect of packaging methods on the quality characteristics of leaf lettuces was studied during storage at low temperature. Using five commercial packaging types: non-perforated PP (polypropylene) film bags, PP film roll, perforated PP film bags, PET (polyethyleneterephthalate) trays, and micro-perforated LDPE film bags, changes in color, respiration rate, and weight loss of leaf lettuces were investigated. Packaging in non-perforated PP film bags minimized color change and weight loss during storage. The leaf lettuces packaged in non-perforated PP film bags, among the five packaging choices, showed good external appearance and offered the greatest sale potential in the domestic market. However, there were no clear differences in the respiration rates of lettuces packed in various ways. The PET tray afforded very good protection of leaf lettuces from physical damage. The results indicate that the marketability of lettuces may be directly affected by the packaging modes employed, and that the optimal packaging may be non-perforated PP film bags; these keep lettuces fresh during low-temperature storage.

• Journal of Conservation Science
• /
• v.37 no.5
• /
• pp.536-544
• /
• 2021

In the present study, safe management and value improvement of bamboo sunblind, which is an item of cultural heritage, were performed by adopting stable conservation treatment methods. The bamboo sunblind used in the present study was excavated from No. 1 catchment site in Baesanseongji, Busan. It was determined that the main material used to make the sunblind was bamboo, and herbal plants were used to weave the bamboo using lacquer as an adhesive agent. All contaminants and soil adhered to the sunblind was removed. Thereafter, the sunblind, which was recovered in the form of blocks, was washed separately after fixing it to a temporary plaster frame and to avoid the blocks from breaking during washing. Then, polyethylene glycol (PEG) impregnation was utilized for the reinforcement treatment. Based on the preliminary test results, the shape of the sunblind was fixed using a stainless-steel frame to prevent physical damage that may occur during the drying process. Thereafter, the bamboo sunblind was vacuum freeze-dried. PEG 20% (in ethyl alcohol) was applied as a surface treatment agent for stabilization the sunblind. After the surface treatment, the bamboo sunblind were joined together to fit the maximum width, and the rectangular shape of the sunblind was restored-as best as possible-while filling in the missing parts by maximizing the use of unknown members such as in the disturbed layers below bamboo sunblind surface. The conservation treatment was completed by fixing the bamboo sunblind into the fabricated frame.

• The Journal of Engineering Geology
• /
• v.31 no.3
• /
• pp.343-355
• /
• 2021

Agricultural reservoirs seek human convenience by supplying agricultural water and providing flood damage effects and rest areas at the same time, but preventing them from aging reservoirs and earthquakes is important. The safety of levees is influenced by field material properties such as soil parameter values of the granular materials that make up the levees, but since precision safety diagnosis or general literature values are diverted, the final safety factors are limited to material properties alone. Since safety factors are determined by physical characteristic values and embankment shapes and have a significant impact on safety factors, accurate contemplation is required when examining reinforced cross sections. Therefore, this study analyzed the case of reasonable and economical reinforcement intersections when designing '◯◯reservoir' in Goheung-geun, Jeollanam-do using the GEP-SLOPE program to enable rational economic design of reinforcement intersections through repeated reviews. As a result of reducing and analyzing the first, second, and third seismic reinforcement of the levees, it was confirmed that the safety ratio was secured even with a significantly smaller amount of reinforcement than the first, second, and lower slopes by obtaining design standards of 1.20. In addition, when determining all seismic reinforcement cross-sectional shapes, it was confirmed that the shape that reinforces only the lower side rather than the upper side of the slope and the entire slope was economical with minimized cross-sectional reinforcement.

• The Journal of the Korea Contents Association
• /
• v.21 no.9
• /
• pp.75-87
• /
• 2021

The purpose of this study is to derive the characteristics of interaction design for each stage of content composition so that it can be referred to in the planning and production of virtual reality safety education contents. It was confirmed that each of the following interaction design features was found in the three configuration steps: acquisition of situation response procedure knowledge, accident situation experiential learning, and content confirmation and evaluation. First, it was revealed that the quality of experience was controlled by increasing the fidelity of behaviors and reducing general and repetitive behaviors in order to emphasize the educational content-related experiences in the learner experience stage. Second, in order for learners to easily recognize main interaction objects in order to acquire information on safe behavior procedures in unfamiliar environments, use of spatial UI or signifiers using arrows or symbols, posts that specifically instruct actions, and multisensory signals Therefore, it was found to be important to emphasize essential actions in a way that lowers the degree of freedom of user experience, and the proportion of non-realistic interactions for cognitive interactions was found to increase. Lastly, in the confirmation and evaluation stage of the experience, it is important to use the meta UI to alleviate negative experiences such as physical damage after experiencing a safety accident situation,

• Korean Journal of Remote Sensing
• /
• v.37 no.6_3
• /
• pp.1975-1984
• /
• 2021

Urban expansion results in raising the temperature in the city, which can cause social, economic and physical damage. In order to prevent the urban heat island and reduce the urban land surface temperature, it is important to quantify the cooling effect of the features of the urban space. Therefore, in order to understand the relationship between each object of land cover and the land surface temperature in Seoul, the land cover map was classified into 6 classes. And the correlation and multiple regression analysis between land surface temperature and the area of objects, perimeter/area, and normalized difference vegetation index was analyzed. As a result of the analysis, the normalized difference vegetation index showed a high correlation with the land surface temperature. Also, in multiple regression analysis, the normalized difference vegetation index exerted a higher influence on the land surface temperature prediction than other coefficients. However, the explanatory power of the derived models as a result of multiple regression analysis was low. In the future, if continuous monitoring is performed using high-resolution MIR Image from KOMPSAT-3A, it will be possible to improve the explanatory power of the model. By utilizing the relationship between such various land cover types considering vegetation vitality of green areas with that of land surface temperature within urban spaces for urban planning, it is expected to contribute in reducing the land surface temperature in urban spaces.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.25 no.4
• /
• pp.28-36
• /
• 2021

It is known that buried rebars inside concrete structures are protected from corrosion due to passive layer. It is very important to delay the timing of corrosion or evaluate a detection of corrosion initiation for the purpose of cost-beneficiary service life of a structure. In this study, corrosion monitoring was performed on concrete specimens considering 3 levels of cover depth(60 mm, 45 mm, and 30 mm), W/C(water to cement) ratio(40.0%, 50.0%, and 60.0%) and chloride concentration(0.0%, 3.5%, and 7.0%). OCP(Open Circuit Potential) was measured using agar-based socket type sensors. The OCP measurement showed the consistent behavior where the potential was reduced in wet conditions and it was partially recovered in dry conditions. In the case of 30 mm of cover depth for most W/C ratio cases, the lowest OCP value was measured and rapid OCP recovery was evaluated in increasing cover depth from 30 mm to 45 mm, since cover depth was an effective protection against chloride ion ingress. As the chloride concentration increased, the effect on the cover depth tended to be more dominant than the that of W/C ratio. After additional monitoring and physical evaluation of chloride concentration after specimen dismantling, the proposed system can be improved with increasing reliability of the corrosion monitoring.