영상처리기법을 이용한 균열 진전 측정시스템 개발

류대현,남승훈,김용일,김시천 한국산업안전학회 2002 한국안전학회지 Vol.17 No.4

We proposed a new experimental method which is required to easily observe the growth behavior of fatigue cracks. In the proposed method, the image data of cracks were stored into the computer while the cyclic loading was interrupted. After testing, crack length was determined using an image processing software which was developed by authors. By comparing the data measured by the image processing system with those by the manual measurement with a microscope, the effectiveness of the image processing system was established. If the proposed method is used to monitor and observe the crack growth behavior automatically, the time and efforts for fatigue test could be dramatically reduced.

버섯스프에서 Buffered Sodium Citrate(BSC)의 식중독균에 대한 성장 억제와 BSC와 Sodium Diacetate 혼합물의 E.coli O157:H7에 대한 성장 억제 효과

류시현 誠信女子大學校 生活文化硏究所 2011 生活文化硏究 Vol.26 No.1

식품에 상업적으로 이용되고 있는 Buffered Sodium Citrate(BSC)를 버섯스프에 각각 3%와 4.8%(wt/vol) 첨가한 후, 식중독균인 Salmonella Typhimurium, Escherichia coli O157:H7, Listeria monocytogenes, Staphylococcus aureus를 접종하여 35°C에서 5일간 저장하면서 항균성을 평가하였다.또한 버섯스프에 3%와 4.8%의 BSC, 1% BSC와 0.1% Sodium Diacetate(SDA) 혼합물을 첨가 한 후, 4균주의 E.coli O157:H7 를 접종한 후 항균성을 추가적으로 평가하였다. S. aureus는 4.8%의 BSC를 첨가한 버섯스프에서 저장3일에 1.3 log CFU/ml로 감소한 후 저장 5일에는 최소 검출수준(< 10 CFU/ml)으로 감소하여 접종된 식중독균 중 가장 유의적으로 억제되었다(p<0.05). 버섯스프에 1% BSC와 0.1% SDA 혼합물을 첨가한 후 저장5일에 대조군와 비교한 결과, 4균주의 E.coli O157:H7 가 1.6 log CFU/g만큼 유의적으로 감소하였다(p<0.05). 따라서 잠재적으로 위험한 식품 중 하나인 시판 버섯스프의 미생물적 안전성을 보장하기 위하여 BSC의 첨가 농도를 좀 더 높게 허용할 필요가 있겠다. 또한 BSC와 SDA혼합물은 시판되고 있는 즉석 버섯스프에서 E. coli O157:H7 의 효율적 저해제로 사용될 수 있는 것으로 나타났다.

분화중인 흰쥐 콩팥의 요세관에서 nNOS의 발현

송지현,류시윤,김진,정주영 韓國電子顯微鏡學會 2008 Applied microscopy Vol.38 No.2

Nitric oxide는 콩팥에서 혈류의 조절, 사구체 혈액역동학 및 요세관의 운반에 중요한 역할을 하는 인자로서 최근 세포의 주기조절, 유사분열에도 관여하는 것으로 알려져 있다. 최근 연구결과에 의하면 발생중인 콩팥에서의 nNOS의 발현은 성체와는 다른 것으로 알려져 있으나, 발생중인 콩팥에서의 발현 양상 및 발현시기 등에 대해서 알려진 바 없다. 따라서 본 연구에서는 발생중인 콩팥을 이용하여 분화중인 요세관에서 nNOS의 발현양상을 관찰하고자 하였다. 성체에서 nNOS의 면역반응성은 사구체 보우만주머니의 벽측상피와 치밀반, 내림가는부분 및 수질집합관에 발현되었다. 발생중인 콩팥에서는 임신 15일에 처음 발현하기 시작하였으며, 그 부위는 원위세관의 굵은오름부분이었다. 임신 20일에서 출산후 14일까지 새로이 형성되는 요세관의 굵은오름부분에서 관찰되었으나, 분화를 마친 요세관에서는 그 발현 양상이 감소하였다. 출생후 21일경에는 최종적으로 치밀반에만 국한되어 발현되었다. 속수질에서는 내림가는 부분과 속수질 집합관에서 발현되었으며 그 양상은 수질 중간부위에서 강하게 발현되었으며 시작부위와 말단부위에서는 약하게 발현되었다. 이상의 결과로 보아 굵은오름부분에서의 nNOS의 발현은 요세관의 분화정도와 일치하며 특히 그 발현양상이 분화가 활발한 시기에 강하게 발현되고 분화가 저하된 후에는 발현이 감소하는 것으로 보아 발생중인 콩팥의 성장에 중요한 역할을 할 것으로 생각된다. Nitric oxide (NO) is an important regulator of renal blood flow, glomerular hemodynamics, and tubule transport processes in the kidney. There is also evidence that NO is involved in cell cycle regulation and mitotic division. During development the nNOS expression pattern differs from that observed in adult animals. However, little is known about temporal and spatial patterns of nNOS expression in the developing kidney. The purpose of this study was to establish the time of expression and the distribution of nNOS in the developing rat kidney. Kidneys from 14-, 16-, 17-, 18-, and 20-day-old fetuses, 1-, 4-, 7-, 14-, and 21-day-old pups, and adult animals were preserved and processed for immunohistochemistry. In the adult kidney, nNOS was detected in the parietal epithelium of Bowman’s capsule, macula densa, descending thin limb and inner medullary collecting duct. nNOS immunoreactivity appeared first in the distal tubule anlage at 15 days of gestation, and in all epithelial cells of developing thick ascending limbs (TAL) as well as macula densa of 17- and 18-day-old fetuses. From 20 days of gestation to 14 days after birth, nNOS was expressed in the newly formed cortical TAL, which are located in the medullary ray, whereas in mature TAL of juxtamedullary nephrons, nNOS immunolabeling gradually decreased in intensity and became restricted to the macula densa. In inner medullary collecting ducts, nNOS immunoreactivity appeared first at 7 days after birth in the papillary tip and gradually ascended to the border between outer and inner medulla. In the descending thin limb and parietal epithelium of Bowman’s capsule, weak nNOS immunoreactivity was observed at 14 days after birth and labeling gradually increased to adult levels at 21 days after birth. These results suggest that differential expression of nNOS in the developing kidney is an important physiological regulator of renal function during kidney maturation.

H_2S의 선택적 산화반응에 미치는 변형된 Zeolite X 촉매의 영향

피준현,이종대,박노국,류시옥,이태진 한국공업화학회 2003 응용화학 Vol.7 No.1

The selective oxidation of hydrogen sulfide was studied over Zeolite X catalysts(Zeolite HX, LiX, NaX, KX) that were prepared by ion exchange method. The acidity sequence of modified Zeolite X catalyst was as follow, Zeolite HX >Zeolite LiX> Zeolite NaX >Zeolite KX.The basicity sequence was reverse of acidity one. For the same conditions (reaction temperature: 225˚c space velocity: 20000h^-1), the conversion of hydrogen sulfide was decreased in Zeolite KX > Zeolite NaX > Zeolite LiX > Zeolite HX order. It was determined that the selective oxidation of hydrogen sulfide was influednced by acidity and basicity. In case of Zeolite NaX catalyst, the yield of element surfer 90% can be obtained at reaction temperature(200), the ratio of O2/H2S (0.5).

곰팡이 오염된 사료를 섭취한 개에서 신부전과 calcium oxalate-like crystal

육현정,손화영,류시윤,조성환 충남대학교 수의과대학 동물의과학연구소 2004 動物醫科學硏究誌 Vol.12 No.-

In March and July 2004, 2-year-old female Yorkshire Terrier and 7-year-old female Shih-Tzu were referred to the College of Veterinary Medicine, Chungnam National University. Clinically, two dogs showed anorexia, vomiting and emaciation. The signs had occurred after the dogs were fed diets infected with oxalate-producing fungi. At necropsy, Shih Tzu had severe renal damage with the green-yellowish colored uroliths in the renal pelvis and the both kidneys were extremely reduced in sizes. Microscopically, Yorkshire Terrier had acute nephritis contained necrotized and degenerated tubular epithelial cells in cortex. Numerous calcium oxalate-like crystals were infiltrated into most tubules, especially the proximal convoluted tubules. Shih Tzu showed chronic nephritis with nephrosclerosis displaced by fibrous connective tissue in most areas. The glomeruli had undergone all stages of variation such as degeneration and fibrosis.

기포유동층 반응기 내에서 천연제올라이트를 사용한 아연계 탈황제의 반응특성연구

김동현,정용길,박노국,이종대,전진혁,류시옥,이태진 한국공업화학회 2003 응용화학 Vol.7 No.2

To improve attrition resistance, calcium oxide was added to durable ZZF sorbent. It was named ZZFCa sorbent. The reactivity of ZZFCa sorbent was investigated in the fluidized-bed reactor. The influencesof the sulfur capacity and the regeneration time for various fluidization velocities from 0.07㎧ to 0.20㎧ were investigated for 5-cycles. As a result, ZZFCa sorbent appeared the high sulfur capacity abouve 10gS/100g sorbent. The sulfur capacity of ZZFCa was maintained, although fluidization velocities increased.

노인을 위한 가정배달급식의 포장방법 및 저장조건에 따른 이화학적,미생물학적 품질 변화 2

김혜영,류시현 한국조리과학회 2003 한국식품조리과학회지 Vol.19 No.2

가정배달급식을 통해 노인에게 제공하기 위해 wrap 포장, 상압 및 진공포장 처리되어 모의로 생산된 표고고기전, 갈치조림, 더덕구이를 상온(25℃), 냉장(4℃) 및 냉동(-18℃)에서 각각 5일간 저장하면서 포장방법 및 저장조건에 따른 이화학적, 미생물학적 품질 변화를 평가한 결과는 다음과 같았다. 1. 이화학적 품질변화에서 pH 저장온도별로 차이를 보여 실온저장 시, 1일째 급격히 떨어졌다가 3일부터 증가하였고, 냉장 및 냉동저장 시에는 저장 1일부터 근소하게 증가하였으며, 포장방법간에 뚜렸한 차이는 없었으나 wrap 포장, 상압포장, 진공포장의 순으로 낮아지는 경향이었는데, 더덕구이에서는 표고고기전과 갈치조림에 비해 수치가 낮았다. Aw는 실온저장 시, wrap 및 상압포장에서 1일째 유의적으로 감소하였으나, 냉장저장에서는 감소율이 낮았고, 더덕구이에서는 다른 음식에 비해 약간 낮았다. VBN은 저장기간이 경과할수록, 저장온도가 높을수록 높았고, 포장방법별로는 wrap 포장군에서 상압 및 진공포장군에 비해 높은 경향을 보여 실온저장 5일째 표고고기전과 갈치조림에서 크게 증가하였으며, 더덕구이는 전반적으로 상당히 낮았다. POV는 전반적으로 실온저장 시, 저장 1일부터 유의적으로 증가하였고, 냉장 및 냉동저장에서는 증가율이 낮았으며, 진공포장은 산패를 지연시켰다. 2. 미생물학적 품질변화에서 표준평판균수는 실온저장 1일부터 급격하게 증가하였는데, 더덕구이에서는 wrap 포장에서 저장 5일까지 계속해서 유의적으로 증가하였고, 냉장저장 시, 진공포장에서는 증식이 저장 5일까지 억제되었으며 냉동저장 시, 갈치조림의 상압 및 진공포장에서는 극히 낮게 검출되었다. 대장균군은 표고고기전의 실온저장시, wrap 포장에서 저장 5일째 유의적으로 증가하여 허용한계치에 근접하였고, 표고고기전과 갈치조림의 냉장저장 시, 저장 3일부터 균수가 낮았고, 적용된 음식 모두 냉동저장 시, 진공포장에서는 저장 5일간 검출되지 않았다. 포도상구균은 표고고기전의 실온저장 시, 3일째 wrap 및 상압포장에서 허용한계치를 초과하였고, 냉장저장 시, wrap 포장에서만 저장 5일째 허용한계치를 초과하였다. 갈치조림에서는 모든 저장온도에서 5일간 검출되지 않았고, 더덕구이에서는 냉장 및 냉동저장 시, 저장 5일간 검출되지 않았으나, 실온저장 시, wrap 포장에서는 저장 3일부터, 상압포장에서는 저장 5일간 검출되지 않았으나, 실온저장 시, wrap 포장에서는 저장 3일부터, 상압포장에서는 저장 5일에 허용한계치를 약간 초과하였다. 한편, 살모넬라, 비브리오, 병원성 대장균 O157:H7, 리스테리아균은 모두 검출되지 않았다. 3. 포장방법 및 저장조건에 따른 이화학적, 미생물학적 품질변화에 영향을 주는 변인 분석 결과, Aw는 저장온도, 포장방법 및 저장기간에, VBN은 저장온도 및 기간에 유의적인 영향을 받는 것으로 나타났다. 표준평판균수는 표고고기전에서 저장온도와 저장기간에, 갈치조림에서 포장방법 및 저장기간에 영향을 받았고, 더덕구이의 표준평판균수, 대장군균, 포도상구균은 모두 포장방법에 영향을 받는 것으로 나타났다. 따라서 가정배달급식을 통해 제공되는 음식의 이화학적, 미생물학적 품질을 유지하기 위해서는 진공포장 처리되어 냉장 및 냉동에서 3일간 저장하는 것이 바람직한 것으로 나타났다. Changes in chemical, microbiological quality of pan fried oak mushroom and meat. soy sauce glazed hair tail and roasted dodok in wrap packaging, top sealing, vacuum packaging were evaluated during storage 25'E, 4'E, -18'E for 5 days. The results were as follows: 1) The cases of chilled and frozen storage, there were small increases in the pH from the first day. with no differences between the different packaging methods, with the exception of the vacuum packaging, which was lower. The pH and Aw of the roasted dodok were lower than those of the other foods. The Aw for all three foods at room temperature significantly decreased in the wrap packaging and top sealing on day one, but the rate of reduction was lower when in chilled storage. The VBN increased with increasing length of storage, and temperatures, but the rate of increase was lower in the top sealing and vacuum packaging. The VBN of roasted dodok was considerably lower than with the other foods. The POV increased significantly on the first day of room temperature storage and the rate of increase was low in chilled and frozen storages, and in the vacuum packaging. 2) SPC of the roasted dodok at room temperature increased significantly within five days of storage. but was inhibited within five days in the vacuum packaging with chilled storage. The SPC of the soy sauce glazed hair tail was low in the top sealing and vacuum packaging when in chilled storage. The coliform of the pan fried oak mushroom and meat, on the fifth day of room temperature storage, was close to hazardous conditions for the wrap packaging. From the third day of chilled storage, few coliform were detected in the pan fried oak mushroom and meat, or the soy sauce glazed hair tail, but not in the vacuum packaging, within five days, for all three foods in frozen storage. The S. spp. had exceeded the standard in the wrap packaging and top sealing with the pan fried oak mushroom and meat on the third day at room temperature, but was not detected in the vacuum packaging within five days, and exceeded the standard in the wrap packaging on the fifth day of chilled storage. S. spp. was not detected in the soy sauce glazed hair tail within five days at all storage temperatures. S. spp. was not detected in the roasted dodok within five days of chilled and frozen storage, but was detected from the third day in the wrap packaging, and the fifth in the top sealing, at room temperature, which exceeded the standard. Sal. spp., V. parahaemolyticus, E. 0157:H7, L. monocytogenes were not detected. 3) The Aw was found to be influenced by storage temperature, period and packaging method, while He VBN was significantly influenced by the storage temperature and period. Regarding the SPC, the pan fried oak mushroom and meat was affected by the storage temperature and period. while the soy sauce glazed hair tail was influenced by the packaging method and storage period. The roasted dodok's microbiological quality was influenced by the method of packaging. The chemical, microbiological quality of home-delivered meals were preserved to be five days in the vacuum packaging, at. chilled and frozen storage.

노인을 위한 가정배달급식의 생산 및 배송단계에 HACCP 적용을 위한 위해요인 분석 1

김혜영,류시현 한국조리과학회 2003 한국식품조리과학회지 Vol.19 No.2

노인에게 제공하기 위하여 영양이 우수하고 동시에 노인의 기호도가 높은 표고고기전, 갈치조림 및 더덕구이를 선정하여 가정배달급식을 위한 음식의 생산 및 배송단계에 HACCP system을 적용하여 설정한 단계별로 소요시간, 온도상태 측정 및 미생물 품질검사를 모의로 실시한 결과는 다음과 같다. 1. 생산 및 배송단계에서 시간 및 온도 측정 결과, 냉각단계의 실내온도는 표고고기전과 더덕구이가 19.2~20.0'C, 갈치조림이 24.O~25.2'C로 위험온도범위에 노출되어 잠재적인 위험이 제기되었다. 2. 생산 및 배송단계에서 미생물 검사 결과, 원재료인 표고, 갈치, 무우 및 더덕에서 포도상구균이생재료의 허용한계치를 초과하였고, 조리직후부터 배송까지의 표준 평판균수는 기준치 이하로 검출되었으나, 냉각 및 포장단계에서 유의적인 증가를 보였다. 대장균군수는 생재료 및 급식단계음식의 기준치보다 훨씬 낮았으며, 배송단계에서는 전혀 검출되지 않았다. 포도상구균은 표고고기전에서는 전반적으로 극히 낮은 수준으로 검출되었고, 갈치조림과 더덕구이에서는 포장단계에서 wrap 포장처리구만이 허용한계치를 초과한31CFU/g가 검출되었으나, 보관 및 배송단계를 거치면서 감소하여 극히 낮아졌다. 한편, Sal. spp. V. parahaemolyticus, E. coli O157:H7, L. monocytogenes는 모두 검출되지 않았다. 3. 규명된 중점관리점은 표고고기전에서는 원재료의 구입과 검수, 냉각 및 포장단계였고, 갈치조림 및 더덕구이에서는 모두 원재료, 전처리, 냉각 및 포장단계였다. 따라서 가정배달급식의 생산단계에서의 중점관리점에 대한 통제방안으로 검수기준의 명확화, 냉각기의 구비와 자동포장기기의 설치가 이루어져야 하겠다. 또한 노인을 대상으로 한 가정배달급식에서는 노인들의 영양과 기호도를 고려하여 좀 더 다양한음식을 선정하여, HACCP가 적용된 표준레시피를 개발하며, 생산 및 배송단계에 걸쳐 보다 실용적이고 위생적인 품질보존 방안을 마련하여 면역성이 저하된 노인들에게 위생적으로 안전하며 관능적으로도 만족할 수 있는 음식을 제공하여야 하겠다. The purpose of this study was to identify the hazard analysis critical control point on food production and transportation flow, applied to home-delivered meals for the elderly. To carry out this study, pan-fried oak mushroom and meat, soy sauce glazed hair tail, and roasted dodok were selected as high nutrient and preferred foods for the elderly and time, temperature, and microbiological quality(standard plate count, coliform, Salmonella spp, Vibrio parahaemolyticus, Staphylococcus spp., Escherichia coli O157:H7, and Listeria monocytogenes) were measured at various phases of the home-delivered meal production and its transportation flows. The results of this experiments are as follows. The temperature measured at cooling phases during the home-delivered meal production flows was 19.2 ~20.0'('for the pan- fried oak mushroom and meat and the roasted dodok and was 24.0 ~ 25.2'E for the soy sauce glazed hair tail. These temperature were in the potentially dangerous zone. Microbiological analysis showed that S. spp. was higher in the raw ingredients, including oak mushroom, hair tail, radish, and dodok than the standard limit. SPC was lower than the standard limit from cooking to transportation phase, but SPC increased significantly during the cooling and packaging phase. The level of coliform detected was far lower than the standard limit and was not detected at all during the transportation phase. Few f. spp. was detected in the pan-fried oak mushroom and meat. but was found in above standards limit during the wrap packaging phase in the soy sauce glazed hair tail and roasted dodok The level decreased rapidly during the holding and transportation phase. Sal. spp., V. parahaemolyticus, S. spp., E. coli 0157:H7, and L. monocytogenes were not detected. For the pan-fried oak mushroom and meat, the critical control points were during the purchasing and receiving of raw ingredients, cooling, and packaging phases. For the soy sauce glazed hair tail and roasted dodot the critical control points were during the purchasing and receiving of raw ingredients, preparation, cooling, and packaging phases.

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

노인을 위한 가정배달급식의 포장방법 및 저장조건에 따른 물성·관능적 품질 변화 3

김혜영,류시현 한국조리과학회 2003 한국식품조리과학회지 Vol.19 No.3

The purpose of this study was to propose the most effective packaging method and storage conditions to apply to home-delivered meals for the elderly. Changes in the physical and sensory qualities of pan fried oak mushroom and meat, soy sauce glazed hair tail and roasted dodok in wrap packaging, top sealing and vacuum packaging were evaluated during storage at 25, 4 and -18℃, for 5 days. The speed of falling-off in the foods qualities, under chilled and frozen storage conditions did not differ much as the 5 day storage period was too short for a proper assessment. The Sensory characteristics of taste and texture were better evaluated in the chilled than in the frozen storage. The most effective packaging method at all the storage temperatures was the vacuum packaging, which assured the safety of the foods by the removal of oxygen. The lightness, springiness and hardness were significantly influenced by the storage temperature, period and packaging method, while the sensory characters were affected by storage temperature and the relied. In conclusion, the quality of the vacuum packed pan fried oak mushroom and meat and soy sauce glared hair tail, in frozen storage, were still fresh after the five days of the experiment. The shelf-life of those foods with wrap packaging. in chilled storage, were suggested to be three days. The quality of the roasted dodok, with vacuum packaging in chilled storage. was preserved for five days.