• The Journal of Korean Academy of Prosthodontics
• /
• v.54 no.1
• /
• pp.8-13
• /
• 2016

Purpose: The aim of this study was to compare the accuracy of two different styles of mechanical implant torque wrenches before and after sterilization and repeated use. Materials and methods: Thirty new spring-style and friction-style mechanical implant torque wrenches from five different manufacturers were selected as subjects of study and assessed in terms of accuracy. Three manufacturers produced, spring-style (Dio, Neobiotech, Osstem) torque wrenches, and other three manufactures produced friction-style (Dentium, Osstem, Shinhung) torque wrenches. The procedure of target torque measurement was performed 10 times for each device and a digital torque gauge (MGT-12, Mark-10 Corp, USA) was used to record the measurements. All torque wrenches were used repeatedly for 20 times and then sterilized. This whole procedure was repeated 100 times and all torque wrenches were retested. The collected data was analyzed using a SPSS Statistics Analysis program to evaluate the accuracy of the torque wrenches and Mann-Whitney-U test was used for a comparative analysis. Results: After sterilization and repeated use procedure, results did not show any significant difference between error values in the spring-style torque wrench group. However, the results demonstrated an increase in error values within the friction-style torque wrench group (P<.05). Conclusion: There was no difference between the accuracy of new spring-style torque wrenches before and after 100 cycles of sterilization and repeated use (P>.05). There was significant difference between the accuracy of new friction-style torque wrenches before and after 100 cycles of sterilization and repeated use (P<.05). Within the limitation of this study, spring-style torque wrenches were more accurate than friction-style torque wrenches in delivering target torque values.

• Proceedings of the Membrane Society of Korea Conference
• /
• 1993.10a
• /
• pp.40-41
• /
• 1993

생물 ㅏ반응기의 생산성을 높이기 위해서는 반응기내의 미생물 농도를 높이는 것이 필요하다. 미생물 농도를 높이기 위한 한 방법으로써 막을 이용한 미생물 재순환에 대한 많은 연구가 수행되어 왔다. 이러한 연구들은 발효조 밖에서 막을 이용하여 미생물을 분리하여 다시 발효조 내로 순환시키는 방법이 주를 이루어 왔으나 이들은 공정이 복잡하고 고분자 합성막을 이용한 경우 고온 멸균의 어려움이 있는등 산업화하는데 여러가지 문제점을 가지고 있었다.

• Proceedings of the Membrane Society of Korea Conference
• /
• 1991.04a
• /
• pp.19-22
• /
• 1991

생물 반응기내에 미생물 농도를 높이기 위한 한 방법으로써 막을 이용한 미생물 재순환에 대한 연구가 이루어져 왔다. 이러한 연구들은 발효조 밖에서 막을 이용하여 미생물을 분리하여 다시 발효조 내로 순환시키는 방법이 주를 이루었으나 이들은 공정이 복잡하고 고분자 합성막을 이용한 경우 고온 멸균의 어려움 등 산업화하는데 여러가지 문제점을 가지고 있었다.

• Journal of the Korean Applied Science and Technology
• /
• v.32 no.3
• /
• pp.412-417
• /
• 2015

The purpose of this study is to treat the ballast water by shear stress without an environmental pollution and to find out the optimal treatment conditions. The ballast water problem is issued up as the trade activated and the cargos mobilized. To improve this problem, International Marine Organization(IMO) make the rule about the ballast water treatment with specific restrictions. Although many countries have been studying about the ballast water treatment technology, there is almost no technology that can treat the microorganisms under $50{\mu}m$ without any secondary pollution. In this study, we tried to treat ballast water by applying shear stress as the physical treatment for the sterilization and tried to find out the optimal conditions including the 100% sterilizing rate and the best economic condition.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.30 no.3
• /
• pp.199-205
• /
• 2014

Purpose: The purpose of this study was to evaluate the transmission of candida in denture by dental polishing lathe. Materials and Methods: Maxillary complete dentures made from the same model were infected with Candida albicans. The infected dentures were polished by dental polishing lathe with sterile pumice and distilled water. And then sterile maxillary complete dentures were polished with same method. Polishing surface was wiped with a cotton swab and the sample was checked for Candida albicans. The polishing wheel at room temperature was checked for Candida albicans every 24 hours for 3 days. Results: A considerable number of Candida was found on the polished sterile dentures. And the Candida albicans in polishing wheel was detected at up to two days. Conclusion: An anti-infection measure is urgently needed when dental polishing lathe is used for denture polishing, because of the possibility of fungal infection.

• Korean Journal of Food Science and Technology
• /
• v.25 no.4
• /
• pp.404-406
• /
• 1993

In order to detect the gelation of ultrahigh temperature (UHT) treated market milks during storage at 20+1C, the free amino groups were quantified with 2,4,6-trinitrobenzene sulfonic acid, and the measurement of pH values and the alcohol test were monthly carried out. The average tree amino groups were $0.94{\sim}1.11{\mu}M$ at 1 month, $1.95{\sim}2.17{\mu}M\;at\;5{\sim}6$ month and $4.95{\sim}6.36{\mu}M$ at 12 month. The pH values at the same time as above were $6.72,\;6.49{\sim}6.55\;and\;6.14{\sim}6.16$, respectively. The alcohol test showed positive results at $5{\sim}6$ month, which could indicate the casein instability and beginning of gelation. These results suggest that the gelation of UHT market milks could he predicted through checking some chemical parameters weekly and be helpful for quality control.

• Korean Journal of Microbiology
• /
• v.47 no.1
• /
• pp.87-91
• /
• 2011

The aim of this study was to compare the performance of conventional culture and real-time PCR for detection of Cronobacter spp. in powdered foods. Infant formula, baby food and Misugaru inoculated with Cronobacter were enriched in distilled water as first enrichment step, followed by incubating in Enterobacteriaceae enrichment (EE) broth as second enrichment step. A loopful of enriched sample was streaked onto Druggan-Forsythe-Iversen agar, followed by incubating at $37^{\circ}C$ for 24 h. One milliliter of the enriched distilled water and EE broth were used in real-time PCR assay. No statistical differences were observed in the number of positive samples between culture method and real-time PCR (p>0.05) in all types of food samples. The number of positives of real-time PCR was higher in the first enrichment media (distilled water) than the second enrichment media (EE broth), though there was no significant difference (p>0.05). It appears that some components of the second enrichment broth, EE broth, inhibit the reaction of real-time PCR. These results show that real-time PCR using a single enrichment with distilled water could be useful as an effective screening method for detection of Cronobacter while saving much time and labor compared to conventional culture method.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.36 no.3
• /
• pp.158-167
• /
• 2020

Purpose: The purpose of this study was to study the effects of the utilization of ethanol solution in infection control of dental implant hand drivers, a common practice in dental prosthodontic clinics. Materials and Methods: Infection control methods were divided into two groups. One swabbed with 83% ethanol gauze and the other immersed in 83% ethanol solution for 30, 60, 90, 120, 150, 180 and 300 second intervals after inoculation of the dental implant hand drivers with Staphylococcus aureus. After measuring the number of colony forming units and analyzing the optical density, the effects of infection control in the experimental group were compared with the positive control group without infection control after inoculation with bacteria and the negative control group without inoculation with bacteria after sterilization. Results: The number of colony forming units and optical density analysis showed a statistically significant difference compared to the positive control. On the other hand, there was no statistically significant difference between the negative control and the group immersed in the 83% ethanol solution for more than 150 seconds. Conclusion: It is recommended to use the ethanol solution as a pre-cleaning process before sterilization, since the intermediate-level disinfection method using ethanol solution alone for the infection control of the dental implant hand driver cannot clinically secure the sterility.

• 한국신재생에너지학회:학술대회논문집
• /
• 2010.11a
• /
• pp.104.2-104.2
• /
• 2010

농산 부산물인 볏짚을 이용하여 수송연료인 휘발유를 대체할 수 있는 바이오에탄올을 생산하기 위한 전단계인 전처리와 당화에 대한 연구를 수행하였다. 볏짚은 농산 부산물 중에서 비교적 발생량이 많으며, 목질계 바이오매스에 비해 소프트하기 때문에 전처리가 용이하다는 장점이 있다. 전처리 방법으로는 여러 가지가 있으나, 본 연구에서는 증기폭쇄에 의한 전처리 방법을 채택하였다. 당화실험은 생물학적 방법인 효소당화를 하였다. 전처리 실험결과 온도가 낮고 처리 시간이 짧을수록 고형물 및 삼성분에 대한 수율이 높은 것으로 나타났다. 삼성분 중의 Glucan 수율은 $180^{\circ}C$ 실험에서 68-71%를 보였으며, $200^{\circ}C$ 실험에서는 59-64%를 보였다. Xylan은 거의 대부분이 소실되어 Xylan을 회수하는 전처리로써는 적합하지 않은 방법으로 나타났다. 반면 Lignin은 거의 제거가 되지 않았다. 당화 실험결과 $180^{\circ}C$에서 전처리한 폭쇄재는 당화 수율이 50%에도 미치지 못하였으나, $200^{\circ}C$에서 전처리한 폭쇄재는 70% 내외를 보여 주었다. 특히 분쇄 세척 멸균한 효소당화 수율은 90%가 넘는 높은 수율을 보였다. 전처리 수율과 당화수율을 종합하여 수율을 분석한 결과 $200^{\circ}C$ 전처리 실험조건에서 효소당화시 미처리 시료와 분쇄 세척 시료보다 멸균까지 실시한 조건에서 Glucan의 종합수율이 55% 내외로 월등히 높은 것으로 나타났다. 증기폭쇄에 의한 볏짚의 전처리는 Glucan의 수율이 낮아 손실이 많은 것으로 나타났으며, 이를 보완할 수 있는 전처리 조건 혹은 다른 전처리 방안이 요구된다.

• Journal of Life Science
• /
• v.23 no.3
• /
• pp.426-431
• /
• 2013

With the objective of developing a functional food source, we established optimal processing conditions for the larvae of Allomyrina dichotoma, which have been used in traditional medicine to treat hepatic disorders in Korea. Without suitable processing, the larvae are difficult to consume as a food because of their disgusting taste and smell; moreover, in this form they might be a potential microbial hazard. In this study, we investigated the effect of feeding material, sterilization, and powdering after freeze-drying on the food quality of the larvae of A. dichotoma and on cytotoxicity against Raw 264.7 cells. Three to five days feeding with the sawdust from discarded oak-trees is sufficient for the breeding process. The sawdust was sterilized by vapor for five minutes. Sterilization of the larvae at a high temperature ($115^{\circ}C$ for 5 min, 0.9 $kgf/cm^2$) is necessary to eliminate pathogenic bacteria and fungi. The results of the cytotoxicity assay showed no toxicity in the prepared extract from larvae of A. dichotoma. In addition, to prepare the larvae for human consumption, various feeds were used and the smell, color, and taste were evaluated. Our results suggested that larvae of A. dichotoma could be developed as food source when a suitable processing method is established.