Poly(vinyl alcohol) nanocomposites containing reduced graphene oxide coated with tannic acid for humidity sensor

Lim, Min-Young,Shin, Huiseob,Shin, Dong Myung,Lee, Sang-Soo,Lee, Jong-Chan Elsevier 2016 Polymer Vol.84 No.-

<P><B>Abstract</B></P> <P>Poly(vinyl alcohol) (PVA) nanocomposites were prepared by a solution casting method using a reduced graphene oxide coated with tannic acid (rGO-TA) as a filler. The rGO-TA was simply prepared by mixing tannic acid (TA) with graphene oxide (GO). The simple mixing process was found to be effective to reduce GO and to produce covalently-grafted TA layers on the reduced GO. The mechanical properties of PVA were much improved by the addition of rGO-TA because the TA layers increased the compatibility of the reduced GO with PVA matrix. For example, Young's modulus and elongation at break values of PVA were increased by 34.0 and 56.9%, respectively, by adding 1.0 wt% of rGO-TA. In addition, the PVA nanocomposites showed excellent humidity sensing properties over the wide relative humidity range and the long-term stability due to the conductive property of the reduced GO and the enhanced mechanical strength by the effective incorporation of rGO-TA into the PVA matrix.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The rGO-TA was prepared by a facile and green method using a low-cost tannic acid. </LI> <LI> The effect of rGO-TA on the properties of PVA nanocomposites has been studied. </LI> <LI> The rGO-TA improved the important properties for PVA-based humidity sensors. </LI> <LI> The PVA/rGO-TAs are promising materials for high-performance humidity sensors. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

폐분체 도료의 재활용 방안에 관한 연구

신동철,김영훈,이순기,김경원,신선명,강헌찬 동아대학교 환경문제연구소 1999 硏究報告 Vol.22 No.1

With the progress of industry, the much more demand of paint around us grows rapidly. However, the whole quantity of raw materials used to make powder coatings is presently imported to fill the domestic needs. Moreover, it is well known that the waste powder coatings from the domestic industries are mostly incinerated. The method of destructing the waste powder coatings by fire causes VOC to be generated, and this results in some serious environmental problems such as air pollution and so on. Therefore, the effective and proper measure must be devised to reuse the waste powder coatings for the purpose of eliminating waste of resources and avoiding the outflow of foreign currency. This study aims to make the plan to recycle the waste powder coatings, and its conclusion is drawn as follows: First, it can be seen that the waste powder coatings with a weak electrostatic power restore gradually to the original state of electrostatic power through the process of fusion and retreatment. Second, it can be estimated that those coatings, with the use of the cyclon, can be removed by dividing a powder of particles less than 10㎛. Third, it can be ascertained that the possibility of reusing the waste powder coatings is proved when it is divided into particles by cyclon and a revolving screen after the process of fusion, rolling, crushing and pulverization.

苛性소다 處理에 依한 밀짚의 飼料價値 增進 硏究

辛炯泰,金贊昊,金鍾奭,宋永祿,林泰鎭 成均館大學校 1982 論文集 Vol.32 No.-

Nylon bag dry matter digestibility (NBDMD, %), nylon bag organic matter digestibility (NBOMD, %) and chemical compositions were analysed to evaluate the nutritive values of 5 varieties of NaOH-treated wheat straws (Jangkwang, Wonkwang, Suwon 210, Suwon 211, Naemil) by using Korean native male goats. Three grams of dried samples by grinding with 2.45㎜ Wiley mill screen were put into a bag 9×14㎠ made of 100 mesh nylon. These bags were put into the ventral sac of the rumen and taken out at the end of 72 hours. They were washed, dried in an oven at 105℃ for 24 hours and weighed “NBDMD” (%) and ashed in an muffle furnace at 600℃ or 24 hours and weighed “NBOMD”(%). The results which were obtained with this experiment were as follows: 1. Nylon bag dry matter digestibility (NBDMD, %) and nylon bag organic matter digestibility (NBOMD, %) of NaOH-treated wheat straws were highly significant different (p<0.01) in different levels of NaOH treatment and of different varieties of wheat straws. 2. The relationship between total mean NBDMD (%, Y_1) of 5 varieties of wheat straws and NaOH concentration (%, X) at 72 hours rumen incubation was: Y_1=34.57+3.56X(r=0.92^**) 3. The relationship between total mean MBOMD (%, Y_2) of 5 varieties of wheat straws and NaOH concentration (%, X) at 72 hours rumen incubation was: Y_2=32.02+2.46X(r=0.92^**) 4. The orders of NBDMD(%) and NBOMD(%) for 5 varieties of wheat straws were Suwon 210, Suwon 211, Naemil, Jangkwang, Wonkwang and Suwon 211, Suwon 210, Naemil, Jangkwang, Wonkwang, respectively. 5. The optimum level of NaOH for improving NBDMD(%) from 5 varieties of wheat straws, on the basis of Blaxter et al. (1961), was 6% NaOH.

동하중 측정 신호처리의 개발에 관한 연구

신영균,이영준,박찬원,신형재,안광희 江原大學校 産業技術硏究所 1998 産業技術硏究 Vol.18 No.-

A high speed and stable A/D conversion data process is required to weigh a mass on moving conveyer weighing platter. The paper presents a new method to obtain stable and fast automatic weighing A/D conversion data process. Dynamic weighting system which is constructed with dual load cell is realized by the stable A/D conversion data preocess algorithm using DSP. The proposed memthod is applied to the real design, and that experimental results showed good performances of the weighing stability.

장력구동방식의 역감제시 시스템

신석두,강원찬,오금곤,김영동 조선대학교 에너지.자원신기술연구소 2000 에너지·자원신기술연구소 논문지 Vol.22 No.2

In this paper, we have developed a new Force-Display system using tendon-driven method. The proposed system is based on the HIR Lab Haptic library, which calculates the real position and renders the reflecting force data to device rapidly. The system is composed of device based tendon-driving method, high-speed controller and Haptic rendering library. The developed system will be used on constructing the dynamical virtual environment. To show the efficiency of our system, we designed simulation program which can display the moving force (attaching, grabbing, rotating) on two virtual point. As the result of the experiment, our proposed system shows much higher resolution than any others.

NCHS와 韓國의 發育 Chart를 基準한 남녀 다운症兒와 精神遲滯兒의 體格發育樣相

朴贊熙,辛尙根,朴英權 東亞大學校 附設 스포츠科學硏究所 1994 스포츠科學硏究論文集 Vol.12 No.-

The purpose of the present study was to examine on the growth pattern of body height and weight from NCHS and Korean growth chart in down's syndrome and mentally retarded children from 7 through 17 years of age. The study design, the subjects and the method were used by the longitudinal data. The subject groups participated in this study were males down's syndrome group(n=16), female down's syndrome group(n=16), male mentally retarded group(n=21), female mentally retareded group(n=14), male normal group(n=90), and female normal group(n=97). Total subjects size was 254. All subjects lived in pusan city, Korea. The data of body height and weight in this study were plotted relative to National Center for Health statistics(1982) and Korean(1975) reference growth charts for stature and weight of American and Korean boys and girls from 2 through 18 years of age, respectively. The conclusion were as follows : 1. In the body height growth chart of NCHS, males and females with down's syndrome were grown within the ranges of 10th P(percentile)∼5th P under, males and females with mentally retardation were grown within the ranges of 10th P∼5th P, respectively. 2. In the body weight growth chart of NCHS, males with down's syndrome were grown within the ranges of 75th P∼25th P, females with down's syndrome were grown within the ranges of 25th P∼50th P, males with mentally retardation were grown within the ranges of 25th P∼10th P, females with mentally retardation were grown within the ranges of 25th P∼50th P, and normal males and females were grown within the ranges of 25th P, respectively. 3. In the body height growth chart of Korean, males with down's syndrome were grown within the ranges of 25th P∼3th P under, females with down's syndrome were grown within the ranges of 10th P∼3th P under, males with mentally retardation were grown within the ranges of 25th P∼10th P, females with mentally retardation were grown within the range of 25th P, and males and females were grown within the ranges of 25th P∼75th P, respectively. 4. In the body weight growth chart of Korean, males with down's syndrome were grown within the ranges of 97th P∼75th P, females with down's syndrome were grown within the ranges of 50th P∼90th P, males with mentally retardation were grown within the ranges of 50th P∼25th P, females with mentally retardation were grown within the ranges of 25th P∼75th p, normal males were grown within the ranges of 25th P∼75th P, and normal females were grown within the ranges of 25th P∼50th P, respectively.

프로그래머 生産性 向上을 위한 實證的 硏究

이병찬,권영직,신호균 대구대학교 산업기술연구소 1989 産業技術硏究 Vol.8 No.-

This study first searched the theoretical background of programmar productivity related with white coller productivity and carried an empirical study for improving the productivity. In experimental study, productivity was not measured by programming cost but by central processing unit time(qualitative aspects), and it was analyzed by COBOL language and 16 bit personal computer. Also, three file organization method and three access method were selected with this experiment. The experiment was conducted with test data for a programs by individual programming. The result was that relative file is more efficient regardless of updated ratio in file organization and dynamic method of random method is more efficient in file access method in case of 500 updated data, random access method in more efficient in the other cases. Also sequential was more efficient in input in case of 500 updated data, and relative file was efficient in output.

통기방식에 의한 고려인삼의 기관분화 특성

정찬문,신주식,이이,장병용 충북대학교 연초연구소 2004 煙草硏究 Vol.19 No.-

기내 배양환경 개선방안의 일환으로 강제통기방식을 이용한 치상배의 발아유형과 생장특성 등을 구명하였다. 강제 통기방식에 의한 배양용기는 기존의 삼각플라스크 배양에 비해 결로 현상이 적었을 뿐 치상절편의 기관분화 및 생장에는 효과가 없었다. 그러나 기내의 공기를 환기시키고 GA등 양액을 추가 공급하여 배양체의 생장을 도모할 수 있는 장점이 있는 반면 오염율은 높았다. 발아유형별 기관분화는 자엽 전개가 양호한 B type이 좋았으나 자엽이 전개하지 않은 A Type과 상배축이 전개한 C Type은 불량하였다. 배(embryo)의 부위별 callus 생장은 자엽과 경근이동부가 좋았고, 배를 전체배양 했을 때 callus 노화가 쉽게 일어났다. 절편체에서 shoot 분화는 자엽과 경근이동부가 양호하였다. For the improvement of in vitro incubation conditions, we analyzed the germination and growth of zygotic embryo explant using forced ventilation. Forced ventilation did not show significant difference in organ formation and growth of zygotic embryo explant compared to triangular flask except for lower dew formation. Ventilation and GA addition to the medium increased not only the growth rate but also the contamination rate. We tested the organ formation rate according to the germination type. B type, which has good cotyledon formation, showed higher organ formation rate, but A type, which has no cotyledon, and C type, which has hypercotyl, showed lower organ formation rate. We tested the callus growth rate according to the part of embryo. Calli from cotyledon and the region between root and stem showed higher growth rate. Calli induced from whole embryo showed early senescence. Cotyledon and the region with root and shoot showed good explant shoot formation.

쇄골 간부 골절 불유합의 수술적 치료 : 재건 금속판 고정 및 골 이식술 Reconstruction Plate Fixation and Bone Grafting

변영수,유찬훈,안혁수,문성건,신동주,박준우 대한골절학회 2003 대한골절학회지 Vol.16 No.2

목 적: 쇄골 간부 골절 불유합에 대하여 관혈적 정복, 재건 금속판 고정 및 골 이식을 시행하고 술후 조기 관절 운동을 허용한 저자들의 경험을 보고하는 것이다. 대상 및 방법: 1997년 1월부터 2001년 12월까지 수술적 치료를 시행한 쇄골 간부 골절 불유합 16예를 대상으로 하였다. 위축성 불유합이 10예, 비후성 불유합이 6예였으며, 수상 후 불유합에 대한 수술까지의 기간은 평균 6.5개월이었다. 수술적 치료로 불유합 부위를 노출시켜 섬유조직을 제거하고 골수강을 천공하였으며, 골편을 정복하고 재건 금속판으로 고정하였으며, 자가 골 이식을 하였다. 수술 후 관절 운동은 1주일 이내에 시작하였다. 결 과: 평균 추시 기간은 22.0개월이었으며, 전 예에서 평균 10.0주에 골유합을 얻었다. 최종 추시 시의 견관절 운동범위는 전 예에서 정상으로 회복되었으며, 나이가 50게 이상인 6예 중 3예에서 동측 견관절에 간헐적인 동통을 호소하였다. 술후 감염, 재검 금속판의 파손, 고정상실, 불유합, 재골절 등의 합병증은 발생치 않았다. 결 론: 쇄골 간부 골절 불유합에 대한 관혈적 정복, 재건 금속판 고정 및 골 이식은 안정성 고정으로 조기 재활이 가능하고 견고한 골유합을 얻을 수 있어 안전하고 확실한 치료방법으로 사료된다. Purpose: The purpose of this study is to present out experience with open reduction, 3.5-㎜ reconstruction plate fixation, bone-grafting, and postoperative early mobilization for nonunions of midshaft clavicular fratures. Materials and Methods: Sixteen patients were treated operatively for nonunions of the midshaft of the clavicle from 1997 to 2001. Ten nonunions were atrophic and six were hypertrophic. Nonunion had been present for an average of 6.5 months. The operative technique included removing the fibrous tissue from the nonunion site and opening the medullary canal, reduction of the fracture and fixation with a 3.5-㎜ reconstruction plate, and bone-grafting. Postoperative mobilization started within one week. Results: The average duration of follow-up was 22.0 months. All fracture were united in an average of 10.0 weeks. All patients had full range of motion of the ipsilateral shoulder, but 3 our of 6 patients who were more than 50 years old complained occasional pain in the ipsilateral shoulder at the final follow-up examination. There were no major complications of postoperative infection, metal failure of the plate, loss of fixation, nonunion, and refracture after removal of the implant. Conclusion: The technique of open reduction, reconstruction plate fixation, and bone-grafting is a safe and reliable method to allow early rehabilitation by stable fixation and to predict a high rate of union for nonunions of midshaft clavicular fractures.

인삼에 있어 변조 장뇌삼 판별에 대하여

정찬문,신주식,이이,장세영 충북대학교 연초연구소 2004 煙草硏究 Vol.19 No.-

시장에서 시판되고 있는 장뇌삼을 재료로 하여 변조 특성 및 이들 변조삼의 진위여부를 판별하고자 그 특성을 조사하였다. 장뇌삼의 변조는 뇌두와 뿌리부위를 주로 변조하는 것으로 나타났다. 뇌두부위는 경흔적수와 수근수를 늘리던가 아니면 뇌두를 장뇌로 변조하였고 뿌리 부위는 지근수 및 지근장을 늘리는 것으로 나타났다. 변조한 뇌두부위의 특징은 먼저 뇌두하단에 있는 동체의 중심주를 요(凹)모양으로 만들고 변조한 뇌두를 철(凸)모양으로 깍아 심지 박듯이 맞추는 것이었다. 또한 각기 다른 인삼의 뇌두를 교묘히 잇대어 장뇌로 만들었고 여기에 수근을 접착하여 오래된 진짜 산삼 형태와 유사하게 변조하였다. 그리고 뿌리부위는 접착면을 절편 자르듯 사선으로 잘라 접착면이 많게 하였고 후에 이들 접착면을 비벼 흔적을 없애는 수법이었다. 변조에 사용된 재료는 인삼 및 출처불명의 약초뿌리를 사용하였고 접착제는 공업용으로 접착성이 강한 것을 사용하였다. For identification of altering methods and distinction of altered long-rhizome ginseng, we studied the properties of long-rhizome ginseng which is being sold in market. Artificial long-rhizome ginsengs were made by modification of rhizomes and roots. Artificial long rhizomes were made by increasing the number of stem vestige root and rhizome root or by modification of rhizome to long-rhizome. Roots were modified by increasing of the number and the length of secondary roots. Artificial long rhizomes were made by carving the rhizome in concave shape and attaching convex shaped modified another rhizome. Those who make artificial ginseng made the altered long-rhizome ginseng looks like real long-aged wild ginseng by elongation of the rhizome by attaching many ginseng rhizomes and attaching of secondary roots. They cut the attaching surface obliquely for increased number of attaching point and removed the vestige by scrubbing the attaching region. They used ginseng, medicinal plant from doubtful origin, and industrial strong adhesives for making altered long-rhizome ginseng.