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>

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.

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.

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.

고무질 보강 식품포장용 LDPE필름의 기계적 강도와 기체투과 선택성

한신,강용구,박찬영 전남대학교 촉매연구소 2000 觸媒硏究 論文集 Vol.21 No.-

To improve the mechanical strength of the functional LDPE packaging film that has deficiency in the strength, though the film is active in vitality and has selective permeability for specific gases such as ethylene and carbon dioxide, this work blends a rubbery polymer, ethylene propylene monomeric rubber(EPM), in the LDPE film, and examines the mechanical strength and the permeability to assess preserving the functionality of freshness keeping of product. Overcoming the defect of incomplete coupling of the ceramic powder to the LDPE film is to use a coupling agent KBM-503( γ -methacryloxy propyl trimethoxy silane) of Shinetsu company in Japan. The optimum blending ratio of the EPM was about 5 percent in weight. The blended film reserves the selective gas permeability in relatively equivalent capacity of the non-rubbery film. The 5 percent EPM blended film has stronger mechanical strength than that made without the EPM, The strength approaches to the pure LDPE film. In conclusion, this work presents the method of improving mechanical strength without any depression in its freshness keeping functionality of the conventional packaging film.

意思決定支援시스템의 接近學派에 관한 考察

이병찬,권영직,신호균 대구대학교 산업기술연구소 1988 産業技術硏究 Vol.7 No.-

This study reviews and compares four relatively unique and distinct decision support system (DSS) schools or perspectives as follows: Decision Analysis Decision Research Decision Calculus Adaptive Design The purpose of this study is to represent a more constructive approach to the concept of a DSS. All four schools address the development and use of computer-based tools that support and aid managers in their role as decision makers. They differ, however, in terms of the nature of the decision situation, the phase of the decision process, the primary aims for a DSS development, the nature of the learning and the phase of the development process.

Prednisolone과 Prednisone의 임상약동학적 평가

신재국,윤영란,차인준,이경훈,장인진,신상구,박찬웅 大韓臨床藥理學會 1994 臨床藥理學會誌 Vol.2 No.1

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.

pH 4.3과 pH 7.0의 과포화용액에서 불소의 농도가 합성 수산화인회석의 결정 성장에 미치는 영향

신현일,박성호,박정원,이찬영 大韓齒科保存學會 2012 Restorative Dentistry & Endodontics Vol.37 No.1

Objectives: Present study was undertaken to investigate the crystal growth onto synthetic hydroxyapatite (HA) seeds in pH 4.3 and pH 7.0 supersaturated solutions with different fluoride concentrations. Materials and Methods: 8 groups of pH 4.3 and 7.0 calcium phosphate supersaturated solutions were prepared with different fluoride concentrations (0, 1, 2 and 4 ppm). Calcium phosphate precipitates yield crystal growth onto the HA seed surface while solutions flow. For evaluation of crystallizing process, the changes of Ca2+, PO43-, F- concentrations of the inlet and outlet solutions were determined. The recovered solid samples were weighed to assess the amount of minerals precipitated, and finally determined their composition to deduce characteristics of crystals. Results: During the seeded crystal growth, there were significantly more consumption of Ca2+, PO43-, F- in pH 4.3 solutions than pH 7.0 (p < 0.05). As fluoride concentration increased in pH 4.3 solution, Ca2+, PO43-, F- consumption in experimental solutions, weight increment of HA seed, and fluoride ratio in crystallized samples were increased. There were significant differences among the groups (p < 0.05). But in pH 7.0 solution, these phenomena were not significant. In pH 7.0 solutions, analyses of crystallized samples showed higher Ca/P ratio in higher fluoride concentration. There were significant differences among the groups (p < 0.05). But in pH 4.3 solution, there were not significant differences in Ca/P ratio. Conclusions: Crystal growth in pH 4.3 solutions was superior to that in pH 7.0 solutions. In pH 4.3 solutions, crystal growth increased with showed in higher fluoride concentration up to 4 ppm.