Poly-(acrylic acid-co-methylacrylate)합성조건에 따른 시멘트계 재료의 물성

조헌영,서정목,이효진,이기환,김진만,맹학영 공주대학교 생산기술연구소 2000 論文集 Vol.8 No.-

The water soluble polymers based on polycarboxlates are come into the spot-light in the detergent fields of CaCO_3, Al(OH)_3 and leather industries. In this research, we synthesized molecular weights(Mn) by changing the concentrations of monomer(acrylic acid-methylacrylate mixture), chain transfer agent(butanethiol) and initiator(ammoniumpersulfate). We investigated the influences on the fluidities(the flow & the mini slump) and the setting times of cement material admixtured with the copolymers by the statistical method. The optimum synthesis formulation of the poly-(AA-co-MA) for cement materials is at the concentrations of monomer 50 M%, chain transfer agent 6.0 M% and initiator 2.0 M%. The number-average molecular weight of that was decided on 7,600 by the viscosity method.

CFRP로 보강된 콘크리트 보의 온도 변화에 따른 영향 분석

조홍동,한상훈,이승수,신진환 한국안전학회 2003 한국안전학회지 Vol.18 No.2

In this study, the behavior characteristics of specimen strengthened with CFRP plate were analyzed according to the change of temperature. CFRP plate itself has a good resistance at the high temperature, but epoxy used as a adhesive is lost its bonding strength at the relatively low temperature. Therefore, this study carries out experiment on the beams slot-bonded with CFRP plates in order to maintain the successful bonding strength of epoxy at high temperature. It is presented that the range of glass transition temperature is 60~80℃ and RC beams slot-bonded with CFRP plate shows more increasing resistance and failure load than that of interface bonded at the high temperature.

피부 병변을 동반한 악성조직구증 1예

조은택,박용관,김진호,강정원,천영욱,전익섭,박유환,전춘해 조선대학교 1995 The Medical Journal of Chosun University Vol.20 No.1

Malignant histiocytosis, originally described in 1939 as histiocytic medullary reticulosis by Scott and Robb-Smith, is a rare histiocytic proliferative disorder that often shows an acute onset and used to progress to death within a few months. This disorder characterized clinically by fever, generalized weakness, lymphadenopathy and hepatosplenomegaly, and shows a variable range of pancytopenia. Extranodal involvement is common, with an incidence ranging from 50% to as high as 90%, skin involves8ment was noted in 10% to 15%. Typical skin lesions were mainly founded in extremity. i.e. erythematous papule and nodule occasionally become to necrosis and ulceration. We experienced one case of malignant histiocytosis in a 46-years-old female. The major clinical findings are fever, malaise, hepatosplenomegaly and erythematous skin lesion. In the laboratory study, pancytopenia is noted on the peripheral blood. And also aggregation of many atypical histiocytes were shown on skin and bone marrow biopsy. So we reported one related case with malignant histiocytosis as well as reviewing literature .

좌제기제가 Propranolol의 생체이용율에 미친영향

조삼상,이진환 조선대학교 약학연구소 1994 藥學硏究誌 Vol.16 No.1

This paper was designed to investigate the influence of suppository bases contained dextran 40000 on the rectal absorption and the dissolution rate of propranolol witepsol suppository. Suppositories were prepared by the fusion method. Propranolol(16㎎) was added to the witepsol base which containing 2.5, 5, 10% of dextran. The release rate of propranolol from witepsol suppository were decreased with increasing dextran content. The maximum blood concentration (C_max) were decreased and time to reach C_max(T_max) were delayed with increasing dextran content and the relative bioavailabilities were increased. After all, Dextran could be applied in sustained release suppository of propranolol.

정상인에서 전기 및 자기 자극을 이용한 설 근육의 전기생리학적 평가

조은미,류종현,안성환,조경원,임건한,김진호,김후원 朝鮮大學校 附設 醫學硏究所 2006 The Medical Journal of Chosun University Vol.31 No.1

Background: Abnormality of lingual muscles is clinically common. But its exact clinical assessment is quite difficult. Evaluation of motor power of the lingual muscles and their neural pathway is limited because of anatomical inaccessibility and individual variation of subjective symptoms. Transcranial magnetic stimulation (TMS) of the human motor cortex is a non-invasive tool to assess the functional integrity of the fast conducting central motor pathways and electrical stimulation of lingual nerve is a conventional method of peripheral nerve conduction. Therefore both study will be helpful to understanding of pathophysiology of lingual abnormality. Until now there is no such report in Korea. This study was conducted to acquire the easier method and normal control values of Korean subjects. Method: We recorded the motor responses from the lingual muscles of 32 healthy subjects (22 men, 10 women) by focal cortical TMS with a circular coil. Motor potentials were recorded by means of surface electrodes applied on the both side of the tongue, following TMS several centimeters lateral from the vertex and parietooccipital cortex and peripheral electrical stimulation of the 12th cranial nerve at the lateral 1/3 point of the line between the midline and angle of mandible. Results: During moderate motor activation, majority of maximal motor response were obtained 4-6cm lateral to the vertex with similar latencies. And the responses from magnetic stimulation of the intracranial segment of hypoglossal nerve were discarded because of difficulty to obtain and unsatisfactory reproducibility. The latency of motor evoked potentials in right cortical stimulation was 10.08 ± 1.17 msec and in left stimulation 10.04 ± 1.32 msec. The amplitudes in right 2.15 ± 1.02, left 2.09 ± 1.11 mV. The latencies electric hypoglossal nerve stimulation were 2.42 ± 0.34 in right, 2.49 ± 0.35 msec in left side. The amplitudes were 2.90 ± 2.37 in right, 2.43 ± 1.86 mV in left side. Central conduction times as calculated by subtracting the response latencies obtained by magnetic and electric stimulation are right 7.65 ± 1.19, left 7.55 ± 1.35 msec. There was no significant difference between man and woman, Conclusion: The method may be efficient, noninvasive, painless, and easy reproduced. With more extensive application to various neurological disorders, it comes close to being an ideal clinical conduction study technique for this cranial nerve.

액체막법에 의한 중금속이온의 분리 및 회수

曺文換,丁學鎭,이상인,金振浩,金始中 江原大學校 附設 環境硏究所 1994 環境硏究 Vol.11 No.-

거대고리 리간드는 금속이온과 선택적으로 결합하는데, 이를 이용하여 에멀젼 액체막을 통한 금속이온의 이동에 관하여 연구를 수행하였다. 금속이온은 유기층에 있는 운반체에 의하여 source phase에서 receiving phase으로 이동한다. 운반체로는 거대고리 리간드인 DBN_(3)O_(3)를 사용하였다. 여기에서 에멀젼 액체막을 통한 금속이온의 이동에 관한 요인과 어떤 금속이온의 선택적 분리에 관하여 검토하였다. 금속이온과 거대고리 리간드 그리고 금속이온과 receiving phase내에 있는 음이온에 대한 안정도 상수를 금속이온의 선택적 이동에 대한 척도로 조사하였다. 납이온이 혼합 용액에서 다른 금속이온보다 높은 이동속도를 나타내었다. Receiving phase내의 음이온이 금속이온의 이동에 중요한 역할을 한다. Receiving phase내에 있는 NO_(3)^(-)을 S_(2)O_(3)^(2-) 대치하면 이동량이 증가함을 보였는데 이는 Pb^(2-)-S_(2)O_(3)^(2-) 상호작용이 Pb^(2+)-NO_(3)^(-) 상호작용보다 크기 때문이다. Macrocyclic ligand has been know to selectively bind with metal ions so that ability applied for the transport of metal ions across the emulsion liquid membrane in this study. The metal ions are transproted from the source phase to the receiving phase by the carrier of the organic phase. Several factors involved in the transport of metal ions acrose the emulsion membrane we reported here and these factors proveided the informations for the selective seperation of some metal ion. Stability constants for cation-macrocyclic ligand and metal ion-anion receiving phase interaction are examined as parameters for the prediction of metal ion transport selectivities Pb^(2+) was transported higher rates than the other metal ions in the mixture solution. The interaction of metal ion to anion in receiving phase is important. S_(2)O_(3)^(2-) in replacement of NO_(3)^(-) in the receiving phase enhances the transport of pb^(2-) since Pb^(2-)-S_(2)O_(3)^(2-) interaction is greater than Pb^(2+)-NO_(3)^(+) interaction.

광중합방식이 콤포머의 변연폐쇄에 미치는 영향

조옥환,한진순,임미경,이수종 대한치과보존학회 2001 Restorative Dentistry & Endodontics Vol.26 No.1

The aim of this study was to evaluate the effect of various polymerization techniques on the microleakage of compomer restorations. Fifty extracted human premolar and molar were used and randomly divided into 5 groups. After cavity preparation, compomer (F2000) was filled according to the manufacturer's directions. All groups, except group 5, were filled using an incremental technique. Group 1was polymerized for 40 seconds at a continuous 485mW/㎠ with a VIP (Bisco, USA) light cure unit. Group 2 was polymerized for 20 seconds at a continuous 345mW/㎠ and then for 20 seconds at 645mW/㎠ with the VIP light cure unit. Group 3 was polymerized at 400mW/㎠, gradually increased to 50mW/㎠ per 10 seconds until 550mW/㎠ was reached; total 40 seconds with a Spectrum 800 (Dentsply Caulk, USA) light cure unit. Group 4 was polymerized for for 3 seconds using an incremental technique with a Flipo (LOKKi, France) light cure unit. Group 5 was polymerized for 3 seconds using a bulk fill technique with the Flipo light cure unit. The specimens were embedded with acrylic resin, and were sectioned with diamond saws in a mesiodistal direction along the longitudinal axis of the tooth so as to pass through the center of the restoration, and three surfaces (occlusal, pulpal, and gingival) were examined with SEM. The results were as follows; 1. Group 5 showed a significantly larger gaps compared to other groups on the gingival, occlusal, and pulpal walls. 2. All groups except group 5 had no statistically significant gap on the gingival, occlusal, and pulpal walls. 3. There was no significant correlation between the amount of enamel on the gingival and occlusal walls and polymerization shrinkage.

도라지 조직배양의 최적배지와 배양조건

정진환,조성환 경상대학교 농업생명과학연구원 2002 농업생명과학연구 Vol.36 No.4

도라지의 약리성 성분을 많이 함유하고 있어 생약재료로서의 가치가 높다. 도라지의 잎, 줄기, 뿌리의 조직부위별 기내배양을 통해 캘러스 유기, 체세포배 형성및 식물체 재분화방법을 조사하였다. 줄기나 뿌리의 절편체보다도 잎 절편체를 치상시 캘러스가 더 잘 유기되었다. 캘러스가 유기배지는 1.0㎎/L2,4-D 와 1.0㎎/L kinetin이 첨가된 MS 기본배지에서 가장 양호하였다. 고체배지 상태에서 유기된 캘러스를 6-7일간 현탁배양하는 과정을 거쳐 활력있는 캘러스 덩어리를 만들고 MS 기본배지에 1.0㎎/L BA와 1.0㎎/L NAA가 혼합된 배지에 치상함으로 75일만에 완전한 도라지 재분화 개체를 얻을 수 있었다. Platycodon grandiflorus DC contains abundant parmaceutical substances and is widely used .is a medicinal herb. Int this study, through tissue cultures of different organelles such as leaves, stems and roots of Platycodon, callus and somatic embryos were induced and whole plants were regenerated. Whole plautlets could be regenerated in 75 days after initiaton of of culture of callus on the MS medium containing 1㎎/L BA and 1㎎/L NAA To facilitate the regeneration, the callus induced from the suspension culture for 6-7 days was transferred to the solid medium. The leaf explant was better than stem or root explants in callus induction and regeneration of whole plantlets.

Weissenberg 寫眞 技法에 의한 酸化마그네슘(MgO)의 結晶構造

이진호,류보영,조소라,김문집,추금홍,서일환,임성수 순천향대학교 1993 논문집 Vol.16 No.3

The structure of MgO crystal is faced centered cubic(FCC) with cell parameters of a=b=c=4.21Å, α=β=γ=90。. The ionic bond length between Mg and O atoms is 2.1Å. This crystal belongs to m3m point group and to Fm3m space group.

Reciprocal Lattice Explorer의 原理와 使用法

徐日煥,李珍昊,秋錦洪,林星秀,柳保盈,朴晶蘭,金文執,趙素羅,金憲俊,李正秀,成百石 충남대학교 자연과학연구소 1993 忠南科學硏究誌 Vol.20 No.2

Reciprocal lattice explorer는 de Jong-Bouman camera와 Buerger precession camera를 合친것이다. 이 explorer를 使用하면 goniometer에 한번 固定한 試料를 使用하여 그 試料의 空間群을 決定하는데 必要한 모든 寫眞을 撮影할 수 있으며 그들은 찌그러지지 않은 逆格子面의 寫眞들이다. 本 論文에서는 de Jong-Bouman 과 Buerger precession 寫眞術의 原理와 使用法을 記述 하였고 또한 de Jong-Bouman의 振動寫眞과 zeroth layer 寫眞으로부터 11個 Laue群의 識別方法도 提示하였다. The reciprocal lattice explorer is an instrument which incorporates the principles of both the Buerger precession and the de Jong-Bouman methods. On the explorer all photographs which are necessary for a space group determination can be taken with a single setting of a crystal and the photographs show undistorted pictures of the reciprocal lattice planes. In this paper, the principles and the usages of the de Jong-Bouman and the Buerger precession photography are described, and a method of 11 Laue group identification using the de Jong-Bouman oscillation and zeroth layer photographs is shown.