• Title/Summary/Keyword: Materials property

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Enhancement of Physical Properties and Efficacy of Pesticide Spray Solution by Addition of Adjuvants (Adjuvant에 의한 농약살포액의 물리성 개선 및 약효증진 효과)

  • Jin, Yong-Duk;Lee, Hee-Dong;You, Oh-Jong;Kim, Jin-Bae;Kwon, Oh-Kyung
    • The Korean Journal of Pesticide Science
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    • v.12 no.4
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    • pp.421-428
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    • 2008
  • This study was carried out to elucidate the effects of adjuvants on physicochemical properties and pest control efficacy of pesticide spray solution. Spray droplet sizes of pesticide solution decreased by addition of adjuvants even though its effect varied according to the pesticides. The adhesive effect of pesticides sprayed on target crops by addition of adjuvants varied according to the properties, the application methods, and the spray volume of pesticides. Wash-off of the deposited amount of active ingredients of the solution of tricyclazole WP and fenobucarb EC by simulated rainfall after spraying on rice plants dramatically reduced by adding adjuvants. The retained amount of active ingredients of the pesticides were $1.5{\sim}4.1$ times higher than those without adjuvants when subjected to simulated rainfall 6 hours after spraying. Addition of adjuvants to the propanil EC spray solution enhanced the control efficacy in barnyard grass, Echinocloa crus-galli Beauv. by $8{\sim}30%$, which showed a potential to reduce pesticide use.

Comparison of Mechanical Properties of Electrospun Nanofiber Web Layered Systems and Conventional Breathable Waterproof Fabrics (전기방사한 나노섬유 웹 처리소재와 상용 투습방수소재의 역학적 특성 비교)

  • Youn, Bo-Ram;Lee, Seung-Sin
    • Science of Emotion and Sensibility
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    • v.13 no.2
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    • pp.391-402
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    • 2010
  • In this study, breathable waterproof materials were prepared by electrospinning. Five kinds of electrospun nanofiber web layered systems with different levels of nanofiber web density, as well as different substrates and layer structures were fabricated, and their mechanical properties (tensile, bending, shear, compression, surface, and thickness & weight) were measured by the KES-FB system and compared with those of conventional breathable waterproof fabrics (densely woven fabric, PTFE laminated fabric and PU coated fabric). The KES-FB measurements demonstrate that the lab-scale nanofiber web layered systems are more flexible and fuller than commercial nanofiber web layered systems, which have a more compact structure than the lab-scale nanofiber web layered systems. Densely woven fabrics and lab-scale nanofiber web layered systems showed lower values of tensile linearity (LT), bending stiffness (B), and shear stiffness (G) than those of PU coated and PTFE laminated fabric. These results indicate that they are more flexible and have less resistance to the shearing movement, corresponding to a more pliable material having a better drape, than PU coated fabrics and PTFE laminated fabrics.

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The Influence of Oxygen Gas Flow Rate on Growth of Tin Dioxide Nanostructures (이산화주석 나노구조물의 성장에서 산소가스 유량이 미치는 영향)

  • Kim, Jong-Il;Kim, Ki-Chul
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.10
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    • pp.1-7
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    • 2018
  • Tin dioxide, $SnO_2$, is applied as an anode material in Li-ion batteries and a gas sensing materials, which shows changes in resistance in the presence of gas molecules, such as $H_2$, NO, $NO_2$ etc. Considerable research has been done on the synthesis of $SnO_2$ nanostructures. Nanomaterials exhibit a high surface to volume ratio, which means it has an advantage in sensing gas molecules and improving the specific capacity of Li-ion batteries. In this study, $SnO_2$ nanostructures were grown on a Si substrate using a thermal CVD process with the vapor transport method. The carrier gas was mixed with high purity Ar gas and oxygen gas. The crystalline phase of the as-grown tin oxide nanostructures was affected by the oxygen gas flow rate. The crystallographic property of the as-grown tin oxide nanostructures were investigated by Raman spectroscopy and XRD. The morphology of the as-grown tin oxide nanostructures was confirmed by scanning electron microscopy. As a result, the $SnO_2$ nanostructures were grown directly on Si wafers with moderate thickness and a nanodot surface morphology for a carrier gas mixture ratio of Ar gas 1000 SCCM : $O_2$ gas 10 SCCM.

A study on the theory of 'Eum-yang-Li-Hap (陰陽離合)' in 6th chapter of 'SoMoon (素問)' 'Yellow Emperior's Nei-ching (黃帝內經)' (황제내경(黃帝內經) 소문(素問) 음양이합론(陰陽離合論)에 대한 고찰(考察))

  • Ok, Do-Hoon;Hong, Won-Sik
    • Journal of Korean Medical classics
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    • v.3
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    • pp.501-552
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    • 1989
  • In this thesis, I intend to study the translational and clinical interpretation through the theory of Eum-Yang-Li-Hap', and reached the following conclusions. 1. 'Eum-Yang (陰陽)' in title, means Yin and Yang as method of understanding nature or humanbody, and 'Li-Hap (離合)' in title, means classification and getting together. Especially there are a view that Eum Yang in title means only meridinans within the limit of human body, but the limit needn't, because the word 'Li-Hap of 3Yin-3Yang (三陰三陽之離合)' as meaning of human meridians in the text. 2. The content of the text is generally seperated into 3 parts, the 1st part contents properties of Li Hap of Yin and Yang. 2nd and 3rd parts content the explanation of property of 3Yin and 3Yang, as example of human meridians with local conception, and content nicknames of 3Yin-3Yang and present the Ideo of 'Kae-Hap-Choo (開闔樞)'. 3. 3Yin-3Yang in the text, many of annotators tried to explanate by three types of conception, of human meridians, of the 'Viscera-Bowels (臟腑)', or of the 'Element motions and Natural factors (運氣)'. I think that these three conceptions could be mixed when the text was written, and regarde for the present that 3Yin-3Yang is explanated by the conception of human meridians. 4. 'Eum (陰)' the head-letter of the nicknames of 3Yin-3Yang, I think that it means 'Jok-Gyeong (足經)' related with the words 'The earth belongs to Yin (地爲陰)' in the text. And it i s considered that further studies should be followed on the tail-words of 3Yin-3Yang's nicknams. 5. Kae-Hap-Choo, Used in similitude" as 'Li (離)' of 3Yin-3Yang, are seperated functions by location of 3Yin-3Yang. In text 'Tae-Yang (太陽)' and 'Tae-Eum (太陰)' act as 'Kae (開)', 'Yang-Myeong (陽明)', and 'Gweor-Eum (厥陰)' act as 'Hap (闔)', 'So-Yang (少陽)' and 'So-Eum (少陰)' act as 'Choo (樞).' But there is other theory that Gweor-Eum act as Choo, and So-Eum act as Hap. 6. The theory of Kae-Hop-Choo, including only Jok-Gyeong being main materials of 'Yook Gyeong-Byeon-Jeung (六經辨證) had influence on development of clinical studies. If the theory of Kae-Hap-Choo receives and unions the ideos of '3 burning-Spaces (三焦)', metabolism, etc. more development of medicine is expected.

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Study on identification of plastic used for modern artwork (플라스틱류 작품의 동정 기술 연구)

  • Yu, Ji A;Chung, Yong Jae;Ham, Seung Wook
    • Analytical Science and Technology
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    • v.27 no.2
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    • pp.100-107
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    • 2014
  • Plastic has been widely used in modern artworks' materials due to its merits of process ability and mass production. In the country, value of plastic artifact is increasing but the field of plastic study is limited to industrial purpose. In this study, Identification methods of plastic were performed by SPME-GC/MS and pyrolysis-GC/MS using trace of samples. As a result of identification using SPME-GC/MS, aromatic compounds were identified from polyvinyl chloride. And alkane compounds were identified from polyethylene, and polypropylene. Aromatic compounds were identified from polystyrene, and diethylene glycol appeared in polyurethane based on polyester was identified from polyurethane. As a result of identification using pyrolysis- GC/MS, aliphatic alkenes compounds and phthalate(DEHP) were identified from polyvinyl chloride. Aliphatic alkenes compounds and phthalate(DIBP) were detected from polyethylene. 1-hexene, etc., were detected from polypropylene, aromatic compounds were identified from polystyrene, and methylene diphenyl diisocyanate which is polyurethane basic material was confirmed from polyurethane. This study suggested that non-destructive SPME and pyrolysis-GC/MS are useful to identify compounds particularly polystyrene and polyurethane. These two analytical methods were expected to be applied for identification of unidentified plastic artworks before conservation treatment.

Foaming Properties and Flame Retardancy of the Foams Based on NBR/GTR Compounds (니트릴고무/타이어고무분말(GTR)를 이용한 발포체의 발포 및 난연 특성에 관한 연구)

  • Moon, Sung-Chul;Jo, Byung-Wook;Choi, Jae-Kon
    • Elastomers and Composites
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    • v.37 no.3
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    • pp.159-169
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    • 2002
  • The improvement of flame retardancy of the foams based on NBR/GTR compounds was conducted by formulating various materials i.e. NBR, GTR, inorganic and phosphorus containing flame retardants, foaming agent, cross-linking agent and activator. The foaming properties, morphology, smoke density and flame retardancy of the specimens were investigated using SEM, LOI tester, smoke density control system and cone calorimeter. The phosphorus containing flame retardant reduces heat release rate, increases the limiting oxygen index and a char formation. The inorganic flame retardant increases the limiting oxygen index and reduces heat release rate with an increased CO yield by char formation, and smoke suppressing effect. The formed char seemed to intercept the oxygen transport and heat transfer into the core area. When the composition ratios of the compounds of NBR/GTR were $100{\sim}80/0{\sim}20 wt.%$, and the ratios of the rubbers/flame retardants were $1/1.55{\sim}3.60 wt.%$, we could developed foams with low heat release rate, high limiting oxygen index($28.0{\sim}39.3$), closed or semi-closed cell of uniformity and reasonable expandability($225{\sim}250 %$).

Development of the Novel Cosmetics Impregnation Material and Study on Makeup W/O Emulsions using It (새로운 화장료 함침재의 개발과 이를 활용한 메이크업 유중수형 에멀전에 관한 연구)

  • Kang, Sungsoo;Kim, Hyeon Jeong;Oh, Se Woong;Park, Sang Wook;Kim, Kyung Seob
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.43 no.1
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    • pp.27-33
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    • 2017
  • Up to now, better convenience and portability were important factors in the development of the cosmetics and achieved by immersing low viscosity makeup water-in-oil (W/O) emulsion into the impregnation material. Conventionally, polyurethane sponges having porous network structures and hard textures have been dominantly used. It has an advantage of easy to manufacture because of its good impregnation property due to its structural characteristics. However, it releases emulsion too much at first use, and shows unexpected dramatic decline during the period of usage. In this study, we studied on makeup W/O emulsion with various features and developed the new foaming sponge, which showed excellent formability and proper absorption and discharge ability of cosmetic composition through the combination of natural rubber (NR) and styrene butadiene rubber (SBR). This impregnation material is characterized by the softness of elasticity like a rubber, high elongation and uniform output. We confirmed that this material can be used to develop makeup products using various oils depending on polarity and controlling the viscosity of the makeup W/O emulsion. Thus, it is concluded that these results provide valuable information in developing new cosmetics impregnation materials.

Changes of Adsorption Properties of Woody Charcoals Prepared by Different Carbonizing Temperature (탄화온도 차이에 의한 목질탄화물의 흡착성 변화)

  • Jo, Tae-Su;Ahn, Byoung-Jun;Choi, Don-Ha
    • Journal of the Korean Wood Science and Technology
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    • v.33 no.3 s.131
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    • pp.45-52
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    • 2005
  • This research was performed to evaluate adsorption behavior of woody charcoals obtained from wood powder, fiber and bark of spruce (Abies sibirica Ledeb). The wood materials were carbonized at various temperatures for 1 hour using experimental rotary kiln without any inert gas. The adsorption capacity of iodine and toluene, specific surface area and removal efficiency of acetic acid and ammonia gas of those charcoals were measured. The higher was the temperature for carbonization, the lower yields of charcoals were. Ash content of bark charcoal was higher than that of wood powder charcoal or fiber charcoal. Elemental analysis of woody charcoal revealed that the content of carbon was gradually lincreased as carbonization temperature was higher. When carbonization temperature was higher, adsorption capacity of woody charcoals for iodine was much improved. Wood powder charcoal and fiber charcoal were more effective for iodine adsorption rather than bark charcoal. Capacity of toluene adsorption was the highest in the charcoal of $600^{\circ}C$. Charcoals produced at high temperature efficiently removed acetic acid gas, while charcoals carbonized at low temperature such as $400^{\circ}C$ were proper to remove ammonia gas. This difference may be explained that the acidity of charcoals depends on the carbonization temperature: charcoals of low temperature indicate acidic property, while those of high temperature turned to alkaline.

Emission Properties of Volatile Compounds from Medicine Herb Residues Board (한약재 찌꺼기로 제조한 한방보드의 휘발성 성분의 방출 특성)

  • Roh, JeongKwan
    • Journal of the Korean Wood Science and Technology
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    • v.44 no.3
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    • pp.430-439
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    • 2016
  • Medicine herb residues boards were manufactured by using medicine herb residues, and emission properties of volatile compounds from boards were examined under various temperature conditions. The volatile compounds were identified with analysis of TD GC/MS by absorbing their flavor components in Tenax tubes. Total 88 volatile compounds were identified from the board. The number of identified compounds at temperature conditions of $25^{\circ}C$, $35^{\circ}C$, and $45^{\circ}C$ were 44, 55, and 65 kinds, respectively. The number of volatile compounds and the total peak area tended to increase with an increase in the temperature. The number of the flavor components detected in all temperature conditions were 34 kinds. Hydrocarbon compounds showed 93% of the detected flavor compounds at $25^{\circ}C$, 92% at $35^{\circ}C$, and 90% at $45^{\circ}C$. Ether compounds accounted for 4% and ketone, aldehyde, and acid-type compounds were detected in a small quantity. The hydrocarbons were composed of 17 kinds of monoterpenes and 39 kinds of sesquiterpenes, which accounted for 11% and 80%, respectively. The most detected compound of monoterpene was limonene, and the major flavor components of sesquiterpenes were ${\alpha}-curcumene$, zingiberene, ${\beta}-elemene$, ${\beta}-selinene$, ${\alpha}-amorphene$, and ${\alpha}-copaene$. Anethole (3.26%) known for ether compounds was detected considerably in all temperature conditions. The results suggest that the manufactured medicine herb residues board include various types of flavor compounds and the flavor compounds might be useful for the manufacture of various products.

Vocation Recognition of the Welfare Teachers Dispatched to the Region Children Centers in Busan (부산지역 아동센터 복지교사의 직업인식)

  • Heo, Jae-Young;Yang, Hae-Sool
    • The Journal of the Korea Contents Association
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    • v.8 no.4
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    • pp.211-226
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    • 2008
  • This thesis is to figure out the job satisfaction and aptitude/vocation recognition of the child welfare teachers dispatched to Region Children Center and provide the basic data for the better children welfare policy in future based on it. First, as for the difference of recognition in the job satisfaction of the child welfare teachers dispatched by the population-statistic property of the research objects, there appeared a meaningful difference by the gender concerning the relation with seniors(p<.01), satisfaction with the office of the child welfare teachers dispatched(p<.01) satisfaction with provided knowledge information(p<.05) and the whole job satisfaction of the child welfare teachers dispatched. As the result of the survey of the recognition on aptitude and job understanding level, there appeared some meaningful differences by the school background on whether or not currently to make efforts to get a better job. In the matter of the pride as to the child welfare teachers dispatched, 27.5% of opinion givers had a clear mission and an objective sense about a current job, and the child welfare teachers dispatched recognized that they felt pleasure and value through the education of students. They understood the difficulty of the management of the children instruction program of region children center in the biggest matters such as the insufficiency of education materials and facilities, and the insufficiency of parents' participation and understanding.