• Fashion & Textile Research Journal
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• v.15 no.4
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• pp.606-612
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• 2013

This paper investigates the physical properties of organic cotton staple yarns manufactured by ring and siro spinning methods as well as analyzes the physical properties of fabric specimens knitted with staple yarns made by these two methods. The breaking stress and evenness of organic ring staple yarns showed the same level for the Japanese specimens as the control yarns; in addition, the same coefficient for the friction of the manufactured yarns and Japanese specimens was also shown. These results makes it possible to manufacture organic staple ring yarns from organic cotton fibers. The tenacity and breaking strain of siro staple yarns were higher than ring staple yarns. The evenness and friction coefficient of siro staple yarns were lower than the ring staple yarns; in addition, hairiness and the number of siro staple yarns was significantly lower than the ring staple yarns. The dimensional stabilities of knitted fabrics by 20 Ne and 30 Ne siro staple yarns were superior to ring staple yarns. The color fastnesses of washing, perspiration and abrasion of knitted fabrics by two spinning methods showed the same level as the 4.5 grade; however, the light fastness of knitted fabric by siro staple yarns was superior to ring staple yarns. It was shown that the siro spinning method (using eco-friendly organic cotton fibers) was applicable to a high sensible knitted garment that overcame drawbacks of organic fibers related to shrinkable properties after washing and low color fastness to light.

• Proceedings of the KIEE Conference
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• 2001.07e
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• pp.35-39
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• 2001

The purpose of this paper is improvement the piezoelectric of Polyvinylidene fluoride(PVDF) organic thin films is fabricated by vapor deposition method. The piezoelectric of PVDF organic thin films attributed to dipole orientation in crystalline region. Also, the piezoelectric characteristic reduced that dipole moments orientation in crystalline region interfered with impurity carriers. Therefore, PVDF organic thin films fabricated with high substrate temperature condition for crystallinity improvement. The crystallinity of PVDF organic thin films fabricated by this condition increase from 47 to 67.8%. The ion density of PVDF organic thin films fabricated by substrate temperature variation from $30^{\circ}C$ to $105^{\circ}C$ decreased from $1.62{\times}10^{16}cm^3$ to $6.75{\times}10^{11}cm^3$ when temperature and frequency were $100^{\circ}C$, 10Hz, respectively. The $d_{33}$ and piezo-voltage coefficient of PVDF organic thin films increased from 20pPC/N to 33pC/N and $162.9{\times}10^{-3}V{\cdot}m/N$ to $283.2{\times}10^{-3}V{\cdot}m/N$, respectively. For the sake of the applications of piezoelectric sensor, we analyzed the output voltage characteristic as a function of the distance between an oscillator of 28kHz and PVDF organic thin film transducer. From this, we found that the output voltage is inversely proportional to the distance. At this time, the period was about $35.798{\mu}s$ and equal the oscillator frequency.

• Korean Journal of Soil Science and Fertilizer
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• v.31 no.4
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• pp.380-383
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• 1998

For the evaluation of the quality of compost, the determination of C/N ratio is mandatory in Korea. Accordingly it is necessary to measure the total carbon content of compost for the quality control of composts. It is, however, not easy to measure the carbon content of compost. For practical purposes total carbon content of compost can be estimated from the total organic matter content, which is estimated by way of ignition loss. For this, it is necessary to establish the factor for conversion of organic matter into carbon. We studied the relationship between the organic matter content determined by ignition method and total carbon content measured by elemental analyzer using 160 compost sample collected from the markets. The relationship between the carbon content and organic matter in those composts was found to be "y(% carbon)=1.995+0.484%(% organic matter)"($r^2=0.943$). This result suggests that total carbon contents of composts can be estimated from the organic matter content.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.04a
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• pp.209-212
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• 1997

Langmuir-Blodgett(LB) method is knowers as a unique method for preparing organic thin films, which can control thickness of the films in molecular level, and many kinds of ultra thin films of functional molecules have been prepared using this method. in this study, the electrical properties of phospholipid monolayers on a water surface was inve stigated by means of stimulus speed(40mm/min, 60mm/min).

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.05a
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• pp.248-251
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• 1996

Langmuir-Biodgett(LB) method is known as a unique method for preparing organic thin films, which can control thickness of the films in molecular level, and many kinds of ultra thin films of functional molecules have been prepared using this method. In this study, The organization of phospholipid monolayers on a water surface was investigated by means of displacement current measurement technique.

• Korean Journal of Chemical Engineering
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• v.35 no.12
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• pp.2496-2503
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• 2018

The short-term stability of high efficiency polymer : nonfullerene solar cells was investigated by employing a quick (ten cycles) current density-voltage (J-V) cycling method. Polymer : nonfullerene solar cells with initial power conversion efficiency (PCE) of >10% were fabricated using bulk heterojunction (BHJ) films of poly[(2,6-(4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)-benzo[1,2-b:4,5b']dithiophene))-alt-(5,5-(1',3'-di-2-thienyl-5,7'-bis(2-ethylhexyl)benzo[1',2'-c:4',5'-c']dithiophene-4,8-dione))] (PBDB-T) and 3,9-bis(2-methylene-((3-(1,1-dicyanomethylene)-6/7-methyl)-indanone))-5,5,11,11-tetrakis(4-hexylphenyl)-dithieno[2,3-d:2',3'-d']-s-indaceno[1,2-b:5,6-b']dithiophene (IT-M). One set of the BHJ (PBDB-T : IT-M) films was thermally annealed at $160^{\circ}C$ for 30min, while another set was used without any thermal treatment after spin-coating. The quick J-V scan (cycling) measurement disclosed that the PCE decay was relatively slower for the annealed BHJ layers than the unannealed (as-cast) BHJ layers. As a result, after ten cycles, the annealed BHJ layers delivered higher PCE than the unannealed BHJ layers due to higher and more stable trend in fill factor. The present quick J-V cycling method is simple but expected to be useful for the prediction of short-term stability in organic solar cells.

• Journal of the Korean Chemical Society
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• v.60 no.6
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• pp.428-435
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• 2016

Effective mastering and learning of basic organic chemical concepts is pivotal to ensure students continue to excel to the higher levels of organic chemistry learning. Concept learning is crucial for first-year organic chemistry students so that they can comprehend and understand a concept better and able to make connection to problems. In the present paper, the authors have implemented the Interactive Anonymous Quiz (IAQ) with "must-have" features in the organic chemistry course as a teaching tool to instill students' interest and enhance conceptual understanding in organic chemistry. The effectiveness of this activity was examined and evaluated through students' reflective writing. Students showed positive learning outcome on the implemented activity as reflected by the reflective writings. In addition, this activity could be employed as an activity to check on students' concept understanding, to instill students' interest in organic chemistry course and to improve on students' weakest topic in organic chemistry in the future classes.

• Korean Journal of Organic Agriculture
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• v.20 no.3
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• pp.297-311
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• 2012

Since 1997, Korean Ministry of Knowledge Economy and Ministry of Environment have established data on some 400 basic raw and subsidiary materials and process like energy, petro-chemical, steel, cement, glass, paper, construction materials, transportation, recycling and disposal etc by initiating establishment of LCI database. Regarding agriculture, Rural Development Administration has conducted establishment of LCI database for major farm products like rice, barley, beans, cabbage and radish etc from 2009, and released that they would establish LCI database for 50 items until 2020 later on. The domestic LCI database for seeds, seedling, agrochemical, inorganic fertilizer and organic fertilizer etc is only at initial stage of establishment, so overseas LCI databases are brought and being used. However, since the domestic and overseas natural environments differ, they fall behind in reliability. Therefore, this study has the purpose to select organic farming materials, survey the production process for various types of organic farming materials and establish LCI database for the effects of greenhouse gas emitted during the process in order to select carbon basic units for agricultural production system compliant in domestic situation instead of relying on overseas data and apply life cycle assessment of greenhouse gas emitted by each crop during the process. As for selecting methods, in this study organic farming materials were selected in the method of direct observation of material and bottom-up method a survey method with focus on the organic farming materials admitted into rice production. For the basic unit of carbon emission amount by the production of 1kg of organic farming material, the software PASS 4.1.1 developed by Korea Accreditation Board under Ministry of Knowledge Economy was used. The study had the goal to ultimately provide basic unit to calculate carbon emission amount in executing many institutions like goal management system and carbon performance display system etc in agricultural sector to be conducted later on. As a result, emission basic units per 1kg of production were calculated to be 0.0088kg-$CO_2$ for charcoal, 0.1319kg-$CO_2$ for grass liquid, and 0.2804kg-$CO_2$ for microbial agent.

• JSTS:Journal of Semiconductor Technology and Science
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• v.12 no.4
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• pp.467-472
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• 2012

In this paper, we present a finite element method (FEM) study on the space charge effects in organic light emitting diodes. The physical model covers all the key physical processes in OLEDs, namely charge injection, transport and recombination, exciton diffusion, transfer and decay as well as light coupling, and thin-film-optics. The exciton model includes generation, diffusion, and energy transfer as well as annihilation. We assumed that the light emission originates from oscillation which thus is embodied as exciton in a stack of multilayer. We discuss the accumulation of charges at internal interfaces and their signature in the transient response as well as the electric field distribution. We also report our investigation on the influence of the insertion of the emission layer (EML) in the bilayer structure.

• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.183-186
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• 1991

In order to prepare the functional organic optic meterials, the capacitive coupled gas flow type plasma polymerization apparatus was designed and manufactured. Styrene and para-Xylene monomer were adopt as organic materisl. Optical constant, refrative index, extinction coefficient of organic thin films by the gas flow type plasma polymerization appratus were determined by envelope method using spectrophotometry. The refractive index of plasma polymerized thin films was decreased in accordance to increase of wave length and discharge time. The extinction coefficient was very small compared with refractive index. From the experimental result of optical constant and film thickness, it was considered that the films which had required optical properties and thickness can be prepared by control of polymerization condition.