• 한국수산과학회지
• /
• 제35권5호
• /
• pp.476-479
• /
• 2002

이 연구에서는 패류의 유생 사육용 식물먹이생물로 배양중인 부착규조 팍판 배양 과정에서 부착 기질인 파판에 어떤 종류의 식물먹이생물이 부착, 출현하며 어떠한 천이 과정을 거치는지 검토하였다. 실험은 비닐하우스내의 약 20톤 콘크리트 직사각형 수조에 파판을 설치하여, 수온 $8.5{\pm}0.3^{\circ}C$, 비중 $1.0250\~1.0260$, 조도 $2,200\~13,000$ lux의 범위에서 20일간 배양하면서 5일 간격으로 관찰하였다. 각 관찰일에 계수한 시료 중 규조류의 세포 수는 시간이 경과함에 따라 매우 빠른 속도로 증가하였으며, 20일간의 실험 기간중 출현한 식물먹이생물은 모두 10종으로 Navicula sp. cf. viridula, Cylindrotheca closteriua Licmophora sp., Pleurosigma normanii,Bacillaria paradoxa, Asterionella glacialis, Stephanoppis sp. cf. turris, Entomoneis sp., Odontella aurita, Cocconeis sp. of, scutellum가 관찰되었다. 한편 각 관찰일별 출현종 수는 5일째가 2종, 10일째 3종, 15일째 10종 그리고 20일째에는 3종이 관찰되었는데, 20일째에는 15일째에 새로이 출현한 7종이 모두 사라졌다. 한편, 실험기간 중 우점종은 Navicula sp. cf. viridula였다.

• 한국지반공학회논문집
• /
• 제28권11호
• /
• pp.69-78
• /
• 2012

강우로 인한 사면의 안정성 평가를 하기 위한 일반적인 해석 방법들은 강우 침투와 흙의 거동 해석을 개별적으로 구분하여 수행하고 있다. 따라서 상용화된 프로그램과 기 개발된 여러 연구자들의 모델들은 불포화 투수계수를 함수비(또는 흡수력)만의 함수로 정의되어 수리-역학적인 특징을 동시에 고려하지 못하고 있는 실정이다. 그러나 실제 침투수는 사면의 거동을 발생시키고, 지반의 토립자들은 다시 재배열되며 이러한 구성관계에 의해 포화 투수계수 뿐만 아니라 불포화 투수계수도 시간에 따라 변화하게 된다. 강우로 인한 사면의 불안정성은 예측된 불포화 투수계수 값을 근간으로 사면 내 흡수력 감소를 계산함으로써 평가되고 불포화 투수계수는 함수비와 간극률의 함수로 정의되어야 한다. 본 논문에서는 기존의 단계적으로 연결된 해석방법이 불포화 지반에서 침투수를 고려하고 흙의 변형을 예측하는 동시연동해석 결과보다 사면 내부에서 예측되는 흡수력의 변화가 시간에 따라 상대적으로 빠르게 감소함을 보여주고 있다.

• 한국환경생태학회지
• /
• 제23권1호
• /
• pp.56-65
• /
• 2009

한국에서 소나무는 문화적, 역사적, 정서적으로 중요한 위치에 있으며, 목재자원 생산이 가능한 수종이다. 소나무의 점유면적은 점차 줄어드는 반면, 참나무류를 비롯한 활엽수림이 증가하는 추세이므로 소나무림 유지를 위한 갱신과 시업법에 관한 연구가 요구된다. 본 연구는 중부지역을 대상으로 소나무에 대한 임분유형 및 구조분석을 통하여 생육환경과 천이과정을 파악함으로서, 안정적이며 지속적인 경영림으로서의 발달과 천연갱신 유도에 그 목적이 있다. 중부지역 소나무림은 당단풍나무군락, 상수리나무군락, 비목군락, 전형군락으로 분류되었으며, 지역에 따라 유형별 다른 특성을 보이고 있었다. 상층에는 소나무가 높게 나타나고 있으나, 중층에서는 참나무류 등 활엽 교목성 수종의 중요치가 높았으며, 하층에서 소나무 출현은 빈약하였다. 따라서 상관적으로 소나무가 생태적 영향력이 높은 것처럼 나타나고 있지만, 차후 자연 상태에서 교목층의 소나무가 고사하면 아교목층 이하 신갈나무, 굴참나무, 졸참나무 등 참나무류가 우점할 것으로 사료되었다. 소나무림의 형질과 생장패턴은 임분유형에 따라 지역별 차이를 보이고 있어 소나무림에 대한 시업도 차별 적용되어야 할 것으로 사료되었다.

• The Journal of Korean Physical Therapy
• /
• 제12권2호
• /
• pp.121-132
• /
• 2000

This study was carried out to determine the influencing of electrical stimulation to cervicothoracic sympathetic ganglion(CTSG; stellate ganglion) u the sympathetic tone. For the purpose of this study. the stimulation was given to both the interferential current stimulation(ICS: AMF 100Hz) group consisting of 10 person(males 8, females 2) and the transcutaneous nerve electrical stimulation(TENS: 100 Hz) group of 10(males 7, females 3) in the right side of the trachea with probe electrodes. Then. the temperature changes on the surfaces of the forehead. cheek, neck and internal ear of cephalocervix, which is subject to the influence of the cervicothoracic sympathetic ganglion, and the palm. which is the end of the upper limbs. measured before. immediately alter. 10 minutes after and 20 minutes after experiment. The results are summarized as follows. 1. The emergence of remarkable Horner's symptoms which appear due to the changes of the tone of cervicothoracic sympathetic ganglion was not seen. However, in the interferential current stimulation group there were two felt the sense of warmth in the facial region and one person who felt it in the upper limbs, and in the transcutaneous nerve electrical stimulation group there was each one person who felt the sense of warmth in the facial region and in the upper limbs, respectively. Both groups have each one person who felt the sense of oppression in the eyelids. Three persons of the interferential current stimulation group and two persons of the transcutaneous nerve electrical stimulation group have the sense of hoarse voice or numbness in the neck. These are the symptoms that appeared during stimulation, so it is difficult for them to be considered as the direct effects of the changes of the tone of cervicothoracic sympathetic ganglion. 2. The t-test was performed to determine the significance between the right, which is the experimental side, and the left, which is the non-experimental side. Significance between the right, which is the experimental side, and the left, which is the non-experimental side. Significant changes were seen in the necks of the interferential current stimulation group and in the cheeks and internal ears of the transcutaneous nerve electrical stimulation immediately after experiment(P<.05). And the interferential current stimulation group showed a very high significance in the cheeks immediately after experiment and in the necks ten minutes after experiment(p<.01). Therefore, it could be seen that the electrical stimulation had an influencing on the changes of body temperature of the cephalocervix. 3. In both the interferential current stimulation group and the transcutaneous nerve electrical stimulation group, the forecheads, checks and necks of the cephalocervix in the experimental side(right) rather than the non-experimental side(left) had mostly a statistically significant rise in temperature immediately after experiment. The one-way ANOVA was carried out to determine the temperature change of on the surface of the body with the lapse of time; before, immediately after, ten minutes after and tewenty minutes after experiment. But no statistical significance was found from both the right and left sides.

• 대한수의학회지
• /
• 제25권2호
• /
• pp.113-123
• /
• 1985

This paper dealt with the distribution of normal mast cells in the spleen, liver and lung on cattle, horses, pigs and dogs, and also degranulation of mast cells in the dogs infected with Rompun (2% Xylazine HCl). The results observed are summarized as follows. Normal mast cells were distributed in spleen, liver and lung on cattle, horse, pig and dog. Mast cells were observed in both red pulp and surroundings of white pulp of the spleen in horse, in the white pulp of the spleen in cattle, in the trabeculae of the spleen in pigs, and in white pulp and red pulp of the spleen in dogs, respectively. Mast cells were observed in the portal triad of the liver in cattle and horses, in both portal triad and interlobular connective tissues of the liver in pigs, and not only the portal triad but also walls of the sinusoids and the central veins in dogs. A large number of mast cells were observed in the interlobular septa and peribronchioles of lung on all the species in this experiment. The mast cells are more numerous in the lungs than other organs. Author considers that numbers of normal mast cells distributed in the tissue is related to the dosage of Rompun in animal. The degranulation of mast cells were observed in the subcutaneous tissues of dog intramuscularly injected with Rompun(0.5ml/times) for 4 or 5 times and subcutaneously injected with Rompun(0.3ml/times) for 4 times. In dog intradermally injected with 0.1ml of Rompun, mast cells were decreased in number at 30 minutes and markedly decreased in number at 2 hours, but more or less increased in number at 3 hours after injection. In addition, the granules of the mast cells were decreased in number at 30 minutes and marked degranulation of the mast cells were recognized at 2 hours after injections, but normal mast cells begun to appear in subcutaneous tissue with the lapse of time from 3 hours after injection. There was also observed local infiltration of neutrophils in subcutaneous tissues of dogs intradermally injected with 0.1ml of Rompun at 30 minutes. At 2 hours after injection, numerous neutrophils and a small number of eosinophils were observed in the site of injection. Conclusionally, Rompun was regarded as a factor which causes the degranulateon of mast cell and the authors considered that histamine released from the mast cells by Rompun might cause relaxation of skeletal muscle.

• 한국식품조리과학회지
• /
• 제16권1호
• /
• pp.65-74
• /
• 2000

본 연구는 부추김치의 담금방법이 관능적 및 미생물학적 특성에 미치는 영향을 조사하여 맛과 저장성을 향상시키는 방법을 모색하는데 그 목적이 있다. 실험처리구로는 소금으로 담근 것(A), 간장으로 담근 것(B), 간장과 들깨가루를 넣어 담근 것 (C), 멸치액젓을 넣어 담근것(D), 멸치액젓과 찹쌀풀을 넣어 담근 것(E)로 하였으며 그 결과는 다음과 같다. 1. 관능적 특성에서 외관, 냄새, 짠맛, 신맛, 감칠맛, 텍스쳐와 전반적인 기호도는 간장을 넣어 담근 처리구 (B)가 비교적 높은 점수를 받았고, 고소한 맛은 들깨가루를 넣은 처리구(C)가 가장 좋은 점수를 받았다. 2. 미생물학적 특성에서 총균수는 발효 전반에는 처리구 C가 많았고, 말기에는 처리구 E가 많았다. 반면에 처리구 A의 총균수가 가장 적었다. 처리구 C는 발효 2일에 최대 젖산균수에 도달했고, 처리구 E는 발효 13일에, 나머지 처리구는 발효 28일에 처리구 A>B>D순으로 최대 젖산균수를 보였다. 발효 말기인 43일에는 처리구 B가 가장 적은 젖산균수를 나타냈다. 분리동정된 젖산균은 Pediococcus속, Streptococcus속, Leuconostoc속, Lactobacillus속의 4가지였으며, Streptococcus속은 적숙기인 발효 8일에 가장 많았으며, 김치산패에 관여하는 Lactobacillus속은 발효가 진행됨에 따라 증가하였다. 이상의 결과를 종합해 볼 때, 본 실험의 조건하에서 발효는 처리구 B>C>E>D>A의 순으로 빨리 진행되었다. 담금방법에 따라 간장은 부추김치의 맛은 좋게 하였으나, 숙성을 빠르게 하였으며, 들깨가루 첨가는 초기 발효를 억제하는 효과가 있었지만, 말기에는 오히려 촉진한 결과로 보아 첨가하는 재료의 종류에 따라 부추김치의 발효 양상에 차이가 있음을 알 수 있었다. 그러므로 부추김치 담그는 목적에 따라 첨가재료를 선택하는 것이 바람직 할 것으로 생각된다.

• 한국식품과학회지
• /
• 제35권2호
• /
• pp.173-181
• /
• 2003

감마선 조사한 국산 및 중국산 옥수수 전분의 저장 중 감마선 조사여부 확인 가능성과 품질 변화를 확인하였다. 점도 측정법을 이용한 검지가능성 시험에서 시료의 점도는 조사 선량에 따라 조금씩 감소하였고, $0^{\circ}C$ 및 $20^{\circ}C$에서 9개월간 저장 중에도 비조사구와 조사구 간의 구분이 가능하였다. Specific parameter를 설정한 결과, 조사처리에 따라 그 값이 감소하여 조사 여부의 확인이 가능하였으며, 조사선량과 specific parameter 간의 상관성은 저장 중 $R^2$값이 0.89이상으로 높게 나타나 조사여부의 검지에 활용할 수 있을 것으로 생각되었다. TBA가는 감마선 조사선량에 비례하여 저장 기간에 따라 유의적으로 증가하였으며, Hunter a값은 조사선량과 유의적인 상관을 나타내었다. 이상과 같이 specific parameter를 이용한 점도측정법은 감마선 조사 후 저장 중에도 조사여부의 screening에 적용이 가능할 것으로 판단되었으며, TBA가의 측정은 판정의 정확도를 높여주는 보조수단으로 기대된다.

• 한국균학회지
• /
• 제11권4호
• /
• pp.163-167
• /
• 1983

$SO_2$가 느타리버섯의 자실체생장(生長)과 갓색에 미치는 영향(影響)을 구명(究明)하기 위하여 $SO_2$의 농도(濃度)를 0.625, 1.25, 2.5 및 5 ppm으로 조절(調節)하고 노출시간을 15, 30, 60, 120 및 180분(分)으로 하여 실험(實驗)한 결과(結果)는 다음과 같다. 1. 느타리버섯의 자실체(子實體)에 $SO_2$를 처리하면 갓색이 변화(變化)하였는데 낮은 처리수준(處理水準)에서는 회청색(灰靑色)을 띄었고 처리수준(處理水準)이 높아질수록 담갈색(淡褐色), 암갈색(暗褐色)으로 변색(變色)이 심하여 졌다. 2. 자실체(子實體) 변색(變色)의 한계점(限界點)은 0.625 ppm 120분(分), 1.25 ppm 30분(分), 2.5 ppm 15분(分)이었고 5 ppm에서는 10분(分) 이내(以內)에 변색(變色)하였다. 3. $SO_2$를 1.25 ppm 120분이상(分以上), 2.5 ppm 60분이상(分以上), 5 ppm 30분이상(分以上) 처리(處理)하면 자실체(子實體)의 생장(生長)이 억제(抑制)되었다. 2.5 ppm, 180분(分), 5 ppm 60분(分)에서는 자실체(子實體)가 고사(枯死)하였다. 4. $SO_2$의 처리(處理)는 담자기(擔子器)의 발육(發育)과 포자형성(胞子形成)을 심하게 억제(抑制)하였고 형성(形成)된 포자(胞子)의 $20{\sim}25%$는 기형화(畸形化)하였다. 5. $SO_2$를 처리(處理)한 자실체(子實體)에서 ethylene 발생(發生)은 검출되지 않았다.

• 대한치과보철학회지
• /
• 제44권2호
• /
• pp.250-263
• /
• 2006

Statement of problem: Ti-alloy has been used widely since it was produced in the United States in 1947 because it has high biocompatibility and anticorrosive characteristics. Purpose: The pure titanium, however, was used limitedly due to insufficient mechanical charateristics and difficult manufacturing process. Our previous study was focused on the development of a new titanium alloy. In the previous study we found that the Ti-Ta-Nb alloy had better mechanical characteristics and similar anticorrosive characteristics to Ti-6Al-4V Material and methods: In this study, the cytotoxicity of the Ti-Ta-Nb alloy was evaluated by MTT assay using MSCs(Mesenchaimal stem cells) and L929 cells(fibroblast cell line). The biocompatibility of the Ti-Ta-Nb alloy was performed by inserting the alloy into the femur of the rabbits and observing the radiological and histological changes surrounding the alloy implant. Results: 1. In the cytotoxicity test using MSCs, the 60% survival rate was observed in pure titanium, 84% in Ti-6Al-4V alloy and 95% in Ti-10Ta-10Nb alloy. 2. In the animal study, the serial follow-up of the radiographs showed no separation or migration revealing gradual bone ingrowth surrounding the implants. Similar radiographic results were obtained among three implant groups pure titanium, Ti-6Al-4V alloy and Ti-10Ta-10Nb alloy. 3. In the histologic examination of the bone block containing the implants. the bone ingrowth was prominent around the implants with the lapse of time. There was no signs of any tissue rejection, degeneration, or inflammation. Active bone ingrowth was observed around the implants. In the comparison of the three groups, the rate of bone ingrowth was better in the Ti-10Ta-10Nb alloy group than those in pure titanium group or Ti-6Al-4V alloy group. In conclusion, Ti-10Ta-10Nb alloy revealed better biocompatibility in survival rate of the cells and bone ingrowth around the implants. Therefore we believe a newly developed Ti-10Ta-10Nb alloy can replace currently used Ti-6Al-4V alloy to increase biocompatibility and to decrease side effects. Conclusion: In conclusion, Ti-10Ta-10Nb alloy revealed better biocompatibility in survival rate of the cells and bone ingrowth around the implants. Therefore we believe a newly developed Ti-10Ta-10Nb alloy can replace currently used Ti-6Al-4V alloy to increase biocompatibility and to decrease side effects.

• Restorative Dentistry and Endodontics
• /
• 제18권1호
• /
• pp.1-26
• /
• 1993

The purpose of this study was to investigate the effect of acid etching on the surface appearance and fracture toughness of five glass ionomer cements. Five kinds of commercially available glass ionomer cements including chemical curing filling type, chemical curing lining type, chemical curing metal reinforced type, light curing tilling type and light curing lining type were used for this study. The specimens for SEM study were fabricated by treating each glass ionomer cement with either visible light curing or self curing after being inserted into a rubber mold (diameter 4mm, depth 1mm). Some of the specimens were etched with 37% phosphoric acid for 0, 15, 30, 60, go seconds, at 5 minutes, 1 hour and 1 day after mixing of powder and liquid. Unetched ones comprised the control group and the others were the experimental groups. The surface texture was examined by using scanning electron microscope at 20 kV. (S-2300, Hitachi Co., Japan). The specimens for fracture toughness were fabricated by curing of each glass ionomer cement previously inserted into a metal mold for the single edge notch specimen according to the ASTME399. They were subjected to a three-point bend test after etching for 0, 30, 60, and 90 seconds at 5 minutes-, 1 hour-and 1 day-lapse after the fabrication of the specimens. The plane strain fracture toughness ($K_{IC}$) was determined by three-point bend test which was conducted with cross-head speed of 0.5 mm/min using Instron universal testing machine (Model No. 1122) following seven days storage of the etched specimens under $37^{\circ}C$, 100% humidity condition. Following conclusions were drawn. 1. In unetched control group, crack was present, but the surface was generally smooth. 2. Deterioration of the surface appearance such as serious dissolving of gel matrix and loss of glass particles occured as the etching time was increased beyond 15 s following Immediate etching of chemical curing type of glass ionomer cements. 3. Etching after 1 h, and 1 d reduced surface damage, 15 s, and 30s etch gave rough surface appearance without loss of glass particle of chemical curing type of glass ionomer cements. 4. Light curing type glass ionomer cement was etched by acid, but there was no difference in surface appearances according to various waiting periods. 5. It was found that the value of plane stram fracture toughness of glass ionomer cements was highest in the light curing filling type as $1.79\;MNm^{-1.5}$ followed by the light curing lining type, chemical curing metal reinforced type, chemical curing filling type and chemical curing lining type. 6. The value of plane stram fracture toughness of the chemical curing lining type glass ionomer cement etched after 5 minutes was lower than those of the cement etched after 1 hour or day or unetched (P < 0.05). 7. Light curing glass ionomer cement showed Irregular fractured surface and chemical curing cement showed smooth fractured surface.