B -NSF계 & 빈졸계 고분자로 변성된 인조석의 물성에 관한 기초 연구

조헌영,서정목,박성기 공주대학교 방재연구센터 1998 공주대학교 방재연구센터 논문집 Vol.2 No.-

In the recent years, artificial stone has been used as exterior finishing materials of bullding. Artificial stone is manufactured with mixture of cement, stone powder and light-weight aggregate. In this research, we tried to find a way of inceasing the properties needed for better quality artificial stone. So, we used β-NSF modifier and vinsol modifier to improve the physical properties of artifical stone. Through this research, we found that the optimum dosage of the β-NSF & the vinsol polymer is 0.1 wt% and 0.05wt% of cement.

Actuator용 PNN-PZN-PZT계 세라믹의 유전 및 전기적 특성

조현철,사공 건,이수호 東亞大學校 大學院 1996 大學院論文集 Vol.21 No.-

In the fields of the optics, precise machine, semiconductors, the micro-positioning actuators are required ofr the control of position in the submicron range. In this study, 0.5Pb(Ni??Nb??)O₃-(0.5-x)Pb(Zn??Nb??)O₃-xPb(Zr??Ti??)O₃ceramics were fabricated by columbite precursor method. The structual, dielectric and electric properties were investigated for sintering condition. The specimen sintered at 1,150(℃) for 1hr, had the highest density and dielectric constant. The resistivity, dielectric constant and density were increased with increasing PZT contents.

β-NSF계와 빈졸계 계면활성제로 변성된 인조석의 물성

조현영,박성기,김진만,서정목 공주대학교 자원재활용 신소재 연구센터 1999 1차년도 센터 성과집 Vol.1999 No.-

건축용 외장재로 사용되는 인조석은 혼합수, 시멘트, 석분, 경량골재를 사용하여 만들어지는데 본 연구에서는 제조단가를 낮추고 물성을 향상시키기 위하여 β-NSF제 계면활성제와 빈졸계 계면활성제를 사용하였다. 본 연구를 통해 β-NSF제와 빈졸계 계면활성제의 최적 배합비가 1.0wt%와 0.1wt%됨을 도출하였고, 새로 개발된 인조석은 기존의 인조석에 비하여 물성이 약 20% 증가하고, 동결융해 저항성이 300% 증가하였다. 그러나, 제조가격은 기존의 제품에 비해 30% 이상 감소된다. Extrior finishing matcrials of artificial stones are manufactured with minture of water, cement, stone powder and light-weight aggregate. In this rescarch, we tried to find a way of increasing the physicl properties and decreasing the manufacturing cost of artificial stone. So we used β-NSF base surfactant and vinsol base surfactant to the artifical stone mixture instcad of light weight aggregatc. The optimum dosage of the β-NSF and the vinsol surfactants for artificial stone are found to be 1.0 wt % and 0.1 wt % of cement, respectively. The physical properties increased ca 20% and the durability for freezing &thawing of the new frtificial stone increased ca 300% while the manufacturing cost of the new artificial stone decreased as much as 30%.

素問·骨空論에 對한 硏究

曺基烈,鄭憲瑩,琴坰樹,朴炅 대한한의진단학회 1998 大韓韓醫診斷學會誌 Vol.2 No.2

The text of the Go1 Gong Ron (骨空論) of the So Moon (素問) was written in the Kap UI Kyung (甲乙經) volume 2 chapter 2 and volume 8 chapter 1. Also it was written in the Tae So (太素) volume 10, 11 and 26. In the Shin Kyo Jung (新校正), they say that it is wriien in the Jeon Won Ki Bon (全元起本) volume 2 and 6. But Wang (王永) interpreted it in volume 16. Also it was introduced in the Ryu Kyung (類經) volume 8, 9, 21 and 22 by Jang Kae Pin (張介賓) in the Myung (明) dynasty. In Go1 Gong (骨空), Gol(骨) means bone and Gong(空) means hole. So Go1 Gong(骨空) means the holes on bone of the human body. A large number of acupuncture points in 12 meridians are located on the holes of bone, and they are playing an important part in the treatment of diseases. In Go1 Gong Ron (骨空論), many points that is choosed when we treat various diseases by acupuncture are mentioned, locations that the holes of bone are distributed in are introduced. So it is called Go1 Gong Ron (骨空論) . This article of the research on the Go1 Gong Ron (骨空論) can be divided into 4 chapters. Summerking the contents of the Go1 Gong Ron (骨空論) in reference to the contents of successive generation note, the contents were as follows. Chapter 1 is about the way to use in treating various diseases what caused by Pung Sa (風??) and deals with the methods of locating acupoints based on a frame. Chapter 2 is written about lines that Conception Vessel (任??), Governer Vessel (????), and Throughfare Vessel (????) pass through, and pathological explanations on the diseases which are belong to those three meridians. The name of each part of the leg and the treatment corresponded to each phase of diseases of the leg are also mentioned in this chapter. Chapter 3 is concretely written about the name and position of the hole on bone of the human body. Chapter 4 deals with moxibustion therapy which we use to treat having an attack of indigestion, being bitten by dog, and feeling cold and heat in turn. Because the ancient men used acupuncture as main treatment of disease, they thought much of acupoint. A large number of acupoints are located on the holes of bone, and are playing an important part in the treatment of diseases. Therefore well understanding of Gol Gong Ron (骨空論) is very important. It is too difficult to understand the Gol Gong Ron (骨空論), because it is written in old Chinese. Consequence of above reason, the writer of this article has researched to find out the exact meaning of that.

Temporary Cement가 상아질 접착제의 접착성능에 미치는 영향

조규증,장헌수 大韓齒科保存學會 1995 Restorative Dentistry & Endodontics Vol.20 No.2

피혁 분으로 변성된 석고계 재료의 물성

조헌영,서정목,전기석,이기환 공주대학교 생산기술연구소 2000 論文集 Vol.8 No.-

Gypsum materials have strong mechanical strengths and great resistance to fire. Also these one are very cheap because of the gypsum is a byproduct from chemical plants. But, these materials have some demerits ; weak water-resistance, heavy specific gravity and low physical properties in bending and tensile strengths. While, leather shaving dust(LSD) is very much produced from leather manufacturing process. The LSD is composed of collagen fibers which is a kind of protein. This one has strong tear and tensile strengths because of the collagen fibers are cross linked during the tanning process of leather. Also the dust has the properties of the high hygroscopic and the superior thermal insulation, but is not degraded any more in neutral condition such as gypsum slurry. In this paper, we have reinforced the physical properties of gypsum with LSD as a filler. From this research, it is decided that the optimum dosage of LSD to gypsum is below 5%(w/w) of the gypsum, and the specific gravity of LSD-gypsum mixture is reduced to 30% relative to gypsum alone.

强靭鑄鐵의 熔接性에 關한 硏究

曺東震,韓俊澤,劉憲一,朴龍鎭,金錫胤,慶在浩 弘益大學校 1974 弘大論叢 Vol.6 No.-

The matrix of ductile cast iron are welded by pre-heating it at 300℃ in the room temperature. Through the mechanical, non-desbructive testing and analysis of the composition. the possibility if arc welding of ductile cast iron are studied as follows; 1. L electrode is the best among them in weldability, impact value and machinability. The next is LB electrode followed by S electrode. C electrode is last. However, the tensile strength showed in the following order: LB, S, L, C. 2. LB, S, L, C, all are available for the welding of cast iron. 3. The above experiment showed that L and LB are good in general. In addition LB is low in price, we therefore prospect that it will be widely used as the electrode for cast iron.

좌새골하정맥을 통하여 중심정맥도관 삽입 3 일 후에 발생한 상대정맥천공과 우흉수 : 증례 보고 A case report

조형찬,손주태,최준영,신일우,이헌근,정영균 대한마취과학회 2002 Korean Journal of Anesthesiology Vol.43 No.4

A 67-year-old male patient had coronary artery bypass graft. Before the induction of general anesthesia, 16 gauge central venous catheter was inserted via left subclavian vein. Initial chest anteroposterior (AP) radiograph showed adequate position, and the central venous pressure measurement through it was satisfactory. This patient's progress was satisfactory, and he was extubated on the second postoperative day. Daily chest AP radiograph had been unremarkable until the third postoperative day, when a right-sided pleural effusion was seen. A day later, the patient complained severe chest pain and dyspnea. We suspected perforation of superior vena cava wall by tip of central venous catheter on the chest computerized tomograph (CT). The injection of radiopaque dye through the central venous catheter confirmed spillage into the mediastinum on the chest CT. Right chest tube was inserted. The patient's condition dramatically improved after chest tube insertion. (Korean J Anesthesiol 2002; 43: 525~530)

멜라민-페놀 수지와 폐 피혁 분으로 만든 복합체의 물성

조헌영,서정목 공주대학교 자원재활용 신소재 연구센터 2002 센터사업 성과집 Vol.- No.1

The leather-resin(ST-MP) composites were made with leather shaving dust(ST) and melamine-phenol resin(MP) by hot pressing method. The mixing ratio of MP:ST, the hot pressing time and the hot pressing temperature for the composites were selected to the experimental factors in this experiment. The physical properties, such as the tensile and the flexural strengths and the extension at maximum of the composite, were tested. From L_9(3^4) orthogonal test, it is found that the ST-MP composites which have tensile strength : 5.8∼12.4 MPa, flexural strength : 20.2∼33.8 MPa, extension at maximum : 0.23∼0.44% are made in this conditions of MP mixing ratio : 150∼200%, hot pressing time : 7∼9 min, and hot pressing temperature : 179∼190℃.

IEEE 802.15.3 WPAN에서 PNC 핸드오버 방안 연구

조무호,정헌주 경주대학교 정보전자기술연구소 2004 情報電子技術論叢 Vol.3 No.-

When a DEV associates with an existing WPAN, the PNC checks the capabilities of the new DEV to see if it is more capable to the PNC of the piconet based on the criteria defined in the IEEE Std 802.15.3 specification. If the new DEV is more capable and the current security policies allow it, then the PNC has the option of handing over control of the piconet to the DEV that has just joined. And, If the PNC is shutting down or wants to leave the WPAN, it also uses the handover process to give control to another DEV in the piconet. However, in the specification it is recommended that only DEV capability information is checked for more PNC capable. For PNC selection, it should consider the radio coverage of new PNC capable DEVs. We propose a PNC selection method which uses PNC candidate list for compassion of PNC capability considering accessibility between DEVs. This method can reduce the processing time because it only checks new DEV and PNC candidate DEVs in the list. If PNC wants, it can immediately hand over control to PNC candidate without the PNC selection process. This is very useful when PNC want to leave or shutdown abruptly. The proposed method provides an accurate PNC selection as well as a rapid PNC handover.