겹침이음실험을 통한 삼중나노소재 혼입 철근콘크리트보의 부착성능에 대한 실험적 고찰

유진규(Jin-Gue Ryu),손동희(Dong-Hee Son),배백일(Baek-Il Bae),유창기(Chang-Gi Yoo),최창식(Chang-Sik Choi) 대한건축학회 2023 대한건축학회논문집 Vol.39 No.10

This study aims to assess the impact of combining triple hybrid reinforced concrete with carbon nanotubes, nanosilica, and graphene oxide on bond strength. The mechanical properties of these materials were evaluated through material testing and assessed bond strength via lap-splice experiments. The material testing revealed that nano-reinforced concrete had a slight increase in compressive strength compared to regular concrete but showed a significant improvement in splitting tensile strength. It also exhibited decreased volumetric strain and Poissons ratio. To understand if these mechanical properties influenced bond strength, laboratory splice experiments were conducted using eight reinforced concrete specimens, varying splice length and cover thickness. The results of the lap-splice experiment showed variations in bond strength depending on the inclusion of nanomaterials in the mixture, with varying increases in bond strength as splice strength changed. This suggests that the combination of these triple nanomaterials does impact the bond performance of concrete.

Safety of a Traditional Korean Medicine, Cheonggan extracts (CGX)

Jang-Woo Shin,Jung-Hyo Cho,Dong-Seok Seo,Nak-Won Sung,Min Kwon,Chang-Gue Son 대한한의학회 2009 대한한의학회지 Vol.30 No.6

Safety of a Traditional Korean Medicine, Cheonggan extracts (CGX): A 2-week Single-dose Toxicity Study in SD Rats and Beagle Dogs

Shin, Jang-Woo,Cho, Jung-Hyo,Seo, Dong-Seok,Sung, Nak-Won,Kwon, Min,Son, Chang-Gue The Society of Korean Medicine 2009 대한한의학회지 Vol.30 No.6

Objectives: To evaluate the acute toxic effects and approximate lethal dose of Cheonggan extracts (CGX) in SD rats and beagle dogs. Methods: Male and female rats were divided into 4 groups (Control, CGX 1250, CGX 2500, CGX 5000) respectively and male and female dogs were divided into two groups respectively (Control, CGX 5000) respectively. A single oral dose of CGX was treated to the rats and dogs. Mortality, signs of gross toxicity, and behavioral changes were observed over 14 days. All animals were observed every hour for 4 hours after administration and once a day thereafter for 14 days. Body weights were determined at $0_{th}$, $7_{th}$, and $14_{th}$ days. All surviving animals were sacrificed and necrotized. Major organs were inspected visually for gross findings. Results: No animals died in any of the groups during the experimental period (2 weeks), rats or dogs. Body weights of rats and dogs during the experiment continuously increased in all groups but there was no significant change. No abnormal clinical signs were observed for 2 weeks after a single administration of CGX in any dose group of CGX, rats or dogs. No abnormal findings in major organs were observed in any group of rats or dogs. Conclusion: CGX does not have acute toxic effects in rats or dogs. Therefore, an approximate lethal dose is assumed to exceed 5000 mg/kg in both rats and dogs.

집단응집력이 농구 경기력에 미치는 영향

장국진,김상식,김계심 龍仁大學校 體育科學硏究所 2005 體育科學硏究論叢 Vol.15 No.1

The purpose of this study is to investigate the influence of group cohesion upon basketball play, and to provide the basic data in order to improve team play. In this study, Group Cohesion Questionnaires were used among 223 subjects who participated in the 33rd National President Cup High School Basketball Match as 12 boy student teams and 11 girl student teams. In this study, I analyzed the relationship among four cohesions as well as general characteristics of subjects. From four cohesions Discriminant Analysis that made distinct the difference of team play was turned out, and the results are as follows; First, the relationship among four cohesions was high in view of the linear relationship among cohesions. Second, the variables of four cohesions based on the results of each descriptive statistics had a great influence on the team play of higher ranking boy student, girl student, and whole teams. Third, in the whole and boy student teams, group-society cohesion, individual-task cohesion, and group-task cohesion were selected as significant variables step by step. Fourth, in the girl student teams, group-society cohesion was selected as significant variables step by step. Fifth, according to the result of unstandardized canonical discriminant analysis in the whole and boy student teams, group-society cohesion had a great influence on the discriminant analysis. Sixth, according to the result of unstandardized canonical discriminant analysis in the girl student team, individual-society cohesion had a great influence on the discriminant analysis.

PUT에 依한 等價 GTO 회로의 스위칭 특성의 연구

金昌圭 진주산업대학교 1979 論文集 Vol.17 No.-

A large turn-off gain characteristic is a very impertant in power transformation equipments. An equivalent GTO circuit as a power transformation device has been composited with a power transistor and a PUT which has very broad frequency rewponse and very small operation anode current. In the experiment, the gate turn-off gain has been 2,000 and maximum turn-off gate current was 1.7㎃ and frequency characteristic has been the range of 0-6K㎐.

Silicone rubber 멤브레인을 이용한 압저항형 저차압센서의 개발

서창택,공성수,심준환,고광락,서현미,김영진,설철규,신장규,이종현 경북대학교 센서기술연구소 1998 센서技術學術大會論文集 Vol.9 No.1

A 4-beam piezoresistive differential pressure sensor using a silicone rubber membrane has been fabricated on the selectively diffused (100)-oriented n/n^(+)/n silicon substrates by an unique silicon micromachining technique using porous silicon etching. The width, length, and thickness of the beam is 120 μn, 600 μm, and 6 μm, respectively, and the thickness of the silicone rubber membrane was 36 gm. By the use of four-beam structure, the mechanical strength of the differential pressure sensor can be highly improved due to smaller shear stress. And the lower sensitivity of the sensor can be simply solved by combining two output signals of half-bridge. The effectiveness of the sensor is confirmed through an experiment and FEM simulation in which the differential pressure sensor is characterized.

移動通信 System의 Digital化에 관한 연구

金昌圭 진주산업대학교 1980 論文集 Vol.18 No.-

These days make a demand for advanced and increased and increased measurement of the information communication, therefore it think of introducing the digital technique in the moving information dependence on traditional analogue transmission. The mathod of digital technique resolves itself into the following threepoints. The 1st points is a digital information 2nd is a braker and 3rd is deta information. (1st) This method become to unnecessarily transfer of wireless channel, therefore, at same time the many number of mebers will be talking over the telephone. (2st) However increasing conversion channel number, by means of a standard crystal oscillator of one thing will be get many a correct cycles. (3rd) This method was a help to the available use of a wireless cycle.

X선 장치 출력 측정에 의한 환자피폭선량의 추정방법

김정민,김창균,신귀순 高麗大學校 倂設 保健大學 保健科學硏究所 2001 保健科學論集 Vol.27 No.1

Recently, They are usually recording the patient information on the Hospital Information System. In the department of Radiology, For the purpose of assuming patient exposed dose, Authors contrived the mathematical calculation model by use of x-ray out put data on the Excel program, if they input the exposure factors (KVp, mAs, thickness), the program could automatically calculate the patient Skin dose. The assuming data by three dimensional equation has average errors within ±15%, therefor We could make good use of clinical field in department of radiology.

고로슬래그를 굵은골재로 사용한 콘크리트강도에 관한 연구

김영인,고창옥,이채규,양승현 조선대학교 국토개발연구소 1994 국토개발연구 Vol.14 No.2

Blast furnace, by-product of iron industry has widely used as reclamation materials for pavement or harbour construction. The studies which make blast furnace slag use as aggregates for concrete have being actived owing to natural aggregates insufficiency. In order to use air cooled blast furnace slag as a coarse aggregate for concrete which was fixed to 440kg, 400kg, 360kg, 320kg, 280kg, 240kg of cement content were performed. This study is aimed to ascertain the feasibility of utilizing the concreate with crushed slag aggregates and to find specific properties such as slump air content, compresive strength, tensile strength, bending strength. The results of this study are summarised as follows; 1. On the base of 320kg of unit cement weight the strength according to each dry day are similar in the condition of 45% of w/c whereas in the condition of 50% of w/c the strength of 7-days are similar, but the strength of 28-days are different. 2. In the relation of δ25 - c/w, the strength of slag concrete is greater than that of crushed storn concrete in condition of epual c/w except 400kg/㎥. 3. Slag of concrete as aggregate is destoryed with mortar. 4. The relation of δ28 and tensile strength is very good(γ = 0.8), the equation of regression analysis is δt= 0.63+0.00598 × 28. 5. The reation of bend strength and w/c is liner(γ = 0.72) the equation of regression analysis is δb=80-0.69w/c. 6. It must be care to abtain equal workability to natual aggregate concrete because the change of water absorption is greate. The water content of slag concrete is more than that of crushed storn concrete to obtain the same workability. It must be careful to use blast furnace slag as a coarse aggregate for concrete. And after investgating the quality of demended concrete carefully, real mixing work must be done.

Chlorophyllin attenuates IFN-γ expression in lipopolysaccharide-stimulated murine splenidc mononuclear cells via suppressing IL-12 production

Yun, Cheol-Heui,Son, Chang Gue,Chung, Dae Kyun,Han, Seung Hyun 경희대학교식량자원개발연구소 2007 硏究論文集 Vol.24 No.-

Chlorophyllin (CHL) is a chlorophyll derivative with anticarcinogen and antioxidant activities. Despite clinical importance of CHL as a potential therapeutics for treating cancer patients, little is known about the immunological properties of CHL. In the present study, we investigated the effect of CHL on the activation of murine splenocytes stimulated with lipopolysaccharide (LPS). RT-PCR analysis showed that LPS-activated IFN-γ expression gradually declined by CHL treatment in a dose dependent manner while mRNA production of TNF-α, IL-2, and FasL was not changed. CHL also suppressed IL-12 production (p70, a heterodimer of p40 and p35) and the mRNA expression of IL-12 p40 and IL-12 receptors (both IL-12Rβ1 and IL-12Rβ2), which are involved in the induction of IFN-γ expression. Furthemore, an electrophoretic mobility shift assay showed that CHL inhibited DNA binding activity of NF-кB, STAT-3, and STAT-4 to their cognate DNA recognition motifs, all of which contribute to the IL-12-induced IFN-γ transcription. Exogenous addition of recombinant IL-12 abrogated the inhibitory effect of CHL on IFN-γ and its mRNA expression in LPS-activated splenocytes. Collectively, these results show that CHL inhibits IFN-γ production by LPS-stimulated splenic mononuclear cells due to down-regulation of IL-12 production. © 2005 Published by Elsevier B.V.