목분-PP 복합체의 난연성과 기계적 특성

손원근,황택성 공주대학교 자원재활용 신소재 연구센터 1999 1차년도 센터 성과집 Vol.1999 No.-

본 연구에서는 표면이 개질된 목분으로 강화된 PP수지 복합체의 (Na₂BO:H₃BO₃=5:1ratio)에 대한 난연특성에 관해 알아보았다. 또한 m-phenylene dimaleimide(PDMI)로 개질된 PP수지와 비개질된 PP수지 복합체의 기계적 특성을 비교하였다. (NH₁)₂HPO₄로 개질된 복합체의 난연성은 boron 혼합물로 개질된 복합체의 난연성보다 우수하였다. 복합체의 충격강도는 목분의 함량이 증가함에 따라 증가되었고, 인장강도는 가소하였다. 개질된 PP수지 복합체의 기계적 강도는 비개질된 수지의 복합체보다 개선되었다. 또한 난연제의 농도가 증가함에 따라 인장강도는 점진적으로 증가되었고, 25 wt%에서 최대값을 나타내었으며, PDMI의 함량이 증가함에 따라 목분-PP 복합체의 인장강도는 16wt%까지 증가되었다. Effects fo (NH₁)₂HPO₄and boron compounds (Na₂BO:H₃BO₃=5:1ratio) on flame retarding characteristics of the surface modified wood powder-filled polypropylene composites were studied experimintally. The mechanical properties of m-phenylenc dimaleimide(PDMI) modified ploypropylene composite were also compared with those of unmodified one. The flame retardance of (NH₁)₂HPO₄ modified wood powder composites was more improved than that of boron compounds modified one. The impact strength of composites increased and the tensile stength of those decreased progressively with an increase of wood powder ldading. The mechanical properties of modified polypropylene composites are more improved than those of unmodified one. The tensil strength also increased marginally with increasing the concentration of flame retardants, yielding a maximum when the concentration of flame retardant is 25.0 wt %. And the tensile strength of the composite was increased up to 16 wt % with increasing concentration of PDMI.

시판복분자 딸기 열매의 탄니 화합물

방근철,김민선,이민원 중앙대학교 약학연구소 1996 약학 논총 Vol.10 No.-

Rubi Fructus(Korean name : Bog-bun-ja) has been used in oriental traditional medicine as the remedies for impotence, pollution, premature ejaculation and frequency of urination etc. By means of chromatographic methods, three hydrolyzable tannins were isolated from the commercial Rubi Fructus. The structures of these compounds were established as gallic acid, pedunculagin and sanguiin H-6 on the basis of physicochemical and spectroscopic evidences.

개에서 관찰된 모기질세포종의 증례보고

조성환,손화영,김혜성,최종윤,류시윤,박배근,윤원기,홍성혁,김덕환 충남대학교 수의과대학 동물의과학연구소 2002 動物醫科學硏究誌 Vol.10 No.-

Pilomatricoma was histopathologically diagnosed in a 2.5-year-old male Alaskan malamute. The patient was referred to Chungnam National University, Veterinary Medical Teaching Hospital with solitary, firm and well-circumscribed mass at shoulder. Grossly, the mass was dome shaped to tumor like and 10 x 8 x 5㎝ in size. Some lesions had gritty or bony consistency and was chalky when sectioned Histopathologic feature included mumerous clusters of tightly arranged, basaloid cells with evenly distributed chromatin and ghost cells were characterized by a central unstained zone. The ghost cells often become calcified and osseous metaplasia was also present.

농장 사육되는 타조에서 나타난 다리 기형의 증례 보고

최종윤,손화영,전무형,조성환,김혜성,류시윤,박배근,이영원,윤원기 충남대학교 수의과대학 동물의과학연구소 2001 動物醫科學硏究誌 Vol.9 No.-

Two farmed young ostrich chicks were applied to pathology laboratory at Chungnam National University. Grossly, one ostrich showed rotated tibiotarsus, the other showed rolled toes. Case 1 ostrich was hypertrophy of fibualis longus and tibial cranialis tendon and gastrocnemius tendon in crus, inflammation of flexor digitorum longus. In histopathological views, myocytes of fiburalis longus were showed hypertrophy and hyperplasia. It is not found any specific feature in X-ray of the case 2 ostrich. Limb deformities were detected frequently in farmed ostrich chicks in 2- to 3 weeks old. Limb deformities were an important cause of mortality in farmed ostrich chicks during the first 10weeks after hatch. Cause of limb deformities were considered a nutrition problem.

우리나라 일부 석면사업장의 석면폐 유병률

백도명,백남원,최정근,손미아,임정기,이원진,문영한,박정선,최병순 大韓産業醫學會 1995 대한직업환경의학회지 Vol.7 No.1

Asbestos industry has been in operation over 60 years in Korea. However, the prevalence of asbestosis has not been yet reported. With rapid turn-over of workers, previous cross-sectional studies of current workers on the job could not find cases with exposures long enough for the development of asbestosis. This study was done to evaluate asbestosis prevalence of those worksites with operation history of more than 20 years. In total, 139 workers from 5 worksites were examined. Asbestos industries covered in the study include 2 asbestos textile, 1 brake lining, and 2 ship repairing worksites. Chest x-ray was taken from all workers and read by two experts familiar with pneumoconiosis classification according to 1980 ILO guidelines. Those with findings compatible with asbestosis were further ckecked with high resolution computerized tomography (HRCT). Pulmonary function tests were done according to ATS guidelines, and occupational and previous medical history was taken through a standardized interview. Air-borne asbestos was measured according to NIOSH method 7400. The air-borne asbestos concentrations ranged from 0.2-1.3 f/cc for asbestos textile, from 0.7-1.0 f/cc for brake lining, and from 6.3-7.8 f/cc during asbestos removal at ship repairing worksite. Of the 139 workers 25 had abnormal chest radiographic findings, and 10 of them had findings compatible with pneumoconiosis. When work history and current asbestos measurements were accounted, 9 workers who had more than 10 years of asbestos exposure history showed chest radiographic findings of pneumoconiosis with Finally, 4 workers showed finding of pulmonary fibrosis and/or pleural thickening at HRCT, and 2 of them had restrictive lung function changes. The study results showed that, among 139 subjects, there were 4(3%) definite asbestosis cases confirmed with HRCT. The prevalence of probable asbestosis was 7% for 10-14 years of exposure, 13% for 15-19 years of exposure, and 23% for 20 or more years of exposure. The prevalence of compensable asbestosis with abnormal lung function was 4-6% for those with 15 or more years of exposure.

돼지생식기호흡기 증후군(PRRS) 바이러스 감염시킨 돼지 기관의 병리학적 관찰

조성환,김현수,윤원기,전무형,류시윤,박배근,손화영,김무강 충남대학교 수의과대학 동물의과학연구소 1996 動物醫科學硏究誌 Vol.4 No.-

The porcine reproductive and respiratory syndrome virus was inoculated into swine tracheal organ culture. The ballooning degeneration of the tracheal ciliated epithelium and a decrease of ciliary activity from the tracheal organs infected with PRRS virus were observed one day post-infection(PI). Tracheal epithelium showed degeneration and focal necrosis 2 days PI. Epithelial necrosis and loss of cilia and epithelial cells became more severe 3 and 4 days PI. An entire loss of cilia and epithelial cells were recognized 4 days PI, however, control tracheal organs were normal during the period of the experiment except a little decrease of ciliary activities with time..

연쇄상구균을 실험감염시킨 넙치치어의 병리조직학적 관찰

조성환,류시윤,김현수,박배근,김덕환,손화영,윤원기,신창호 충남대학교 수의과대학 동물의과학연구소 1999 動物醫科學硏究誌 Vol.7 No.-

Pathological observations were examined after abdominal inoculation in 7∼8㎝ sized flounder (Paralichthys olivaceus) with 1X10^7 cfu/㎖ of Streptococcus faecalis. The infected flounder were clinically observed and weighed a fish body at 0, 5, 10, 15, 20, 25, 30 days post inoculation. In infected group, mortality were 70% and feed efficiency were 7.2%. In non-infected group, mortality were 10% and feed efficiency were 18.2%. Macroscopically, the significant lesions were characterized by protrusions and opacity of the eyes and ulcer of the caudal pecuncle. Histopathologically, the lesions were observed a degeneration. necrosis and inflammatory cells in muscle of the caudal peduncle and a degeneration and necrosis of the rod cells and detached retina from the black pigmented layer

한국 재래 우 및 산양 위장관의 somatostatin cell에 대한 면역조직화학적 분포

조성환,김현수,박배근,윤원기,손화영 충남대학교 수의과대학 동물의과학연구소 1995 動物醫科學硏究誌 Vol.3 No.-

The relative frequency and distribution of somatoatatin immunoreactive cells were investigated by the immunohistochemical method in the gastrointestinal tract of the Korean native cattle and goat. The results obtained were as follows: In the Korean native cattle, somatoststin cells were a few in the pyloric and duodenal region and rarely seen in fundic region, jejunum, ileum, cecum, proximal colon, central coil, distal colon and rectum. In the Korean native goat, somatostatin cells were the most numerous in the pyloric region and the next in the fundic region. And they were a few in the duodenum, not detected in the cecum and sparse in the jejunum, ileum, proximal colon, central coil, distal colon and rectum.

The Binding Properties of Metal Ions with Sulfonated Poly(Ether Ether Sulfone)

Won-Keun Son,Soo-Gil Park 대한전기학회 1999 Journal of Electical Engineering and information S Vol.4 No.2

Speciation of M(II)-Oxalate Complex in an Electrodynamic Cell Dissolving CRUD

Won-Keun Son,Sang Yoon Park,Sion Kim,Changhyun Roh 한국방사성폐기물학회 2023 한국방사성폐기물학회 학술논문요약집 Vol.21 No.2

During the operation of a nuclear power plant (NPP), corrosion products called CRUD (Chalk River unidentified deposit) accumulate on the surface of the primary system. The CRUD components of pressurized light water reactors or heavy water reactors, represented by (NixFe1-x)(FeyCr1-y)2O4, are composed of Fe3O4, NiFe2O4, FeCr2O4, NiCr2O4, etc. Radionuclide such as Co-60 are deposited within this CRUD, so the entire deposited material must be dissolved and removed for decontamination. Chemical decontamination has the advantage of being able to decontaminate a wide metal surface, but has the disadvantage of generating a large amount of secondary waste. Recently, chemical decontamination methods that add an electrodynamic process are being studied to overcome these shortcomings. This technology is a method of dissolving CRUD by applying an electric field in the anodic compartment of a cell separated by CEM. It is a method of accelerating CRUD dissolution by generating a large amount of hydrogen ions in the anodic compartment. Dissolved metal ions pass through the CEM (cation exchange membrane) and move to the cathodic compartment (pH > 12), where they are removed by adsorption or precipitation process. Therefore, the speciation characteristics between decontamination agent (oxalic acid) and metal ions are very important. In this study, we investigated the speciation characteristics of Fe(II), Ni(II), Co(II) - oxalate, which are important complex species in CRUD dissolution cells. The thermodynamic equilibrium constant for hydrolysis of each ion and of M(II)-oxalate were collected and speciation characteristics were analyzed using the MINEQL 5.0 program. From the speciation characteristics of M(II)-oxalate, effective radionuclide removal methods in an electrodynamic cell were considered.