반응표면분석법으로 최적화한 초음파와 저온 블랜칭의 병용처리 조건이 신선편이 양상추의 갈변과 품질에 미치는 영향

김도희 ( Do Hee Kim ),김수민 ( Su Min Kim ),김한빛 ( Han Bit Kim ),문광덕 ( Kwang Deog Moon ) 한국식품저장유통학회(구 한국농산물저장유통학회) 2012 한국식품저장유통학회지 Vol.19 No.4

Enzymatic action and microbial growth degrade the quality of fresh-cut lettuce. Browning, a bad smell, and softening during storage are the major forms of quality deterioration. Health-oriented consumers tend to avoid foods treated with chemicals to maintain their freshness. This study was conducted to evaluate the change in the quality of fresh-cut lettuce with combined low-temperature blanching (LB) and ultrasonication (US). The optimum condition was selected using the response surface methodology (RSM), through a regression analysis with the following independent variables; the ultrasonication time (X1), blanching temperature (X2), blanching time (X3), and dependent variable; `E value (y). It was found that the condition with the lowest ΔE value occurred with combined 90s US and 45℃ 90s LB (US+LB). The combined treatment group (US+LB) was stored at 10℃ for 9 days with the control group and each single-treatment group, with low-temperature blanching and ultrasonication. Overall, the US+LB group had a significantly high L* value, which indicates significantly low a*, b*, ΔE, browning index, PPO, and POD activity values, and a low total bacteria count (p < 0.05). The US+LB group also had the highest sensory score (except for aroma and texture; p > 0.05).

사시나무 근삽수의 저온저장 처리가 클론별 근맹아 발생에 미치는 영향

권순호,박지민,김양길,강혜인,염다빈,김기원,강규석 경상대학교 농업생명과학연구원 2018 농업생명과학연구 Vol.52 No.3

사시나무(Populus davidiana Dode)는 동아시아에 분포하는 산지형 속성수이다. 우리나라에서는 이전 에 치산녹화에 중요한 조림수종이었으며, 줄기 삽목에 의한 증식이 어려워 근삽(Root cutting)을 이용 한 증식이 가능한 것으로 알려져 있다. 근삽은 줄기 삽목에 비하여 클론 개체를 얻는 효율이 낮기 때문 에 근삽을 이용한 개체 증식을 시도할 때 많은 개체를 얻기 위하여는 근맹아 발생량을 높이기 위한 연 구가 필요하다. 이에 본 연구는 사시나무 근삽수의 저온 저장 처리가 근맹아 발생 효율에 미치는 영향 을 알아보고자 수행되었다. 근삽수는 오대 19호를 포함한 총 9개의 클론에서 채취되었다. 실험은 같은 샘플들을 4℃와 24℃의 온도 조건에서 3주간 처리한 다음 항온 유지 온실에서 근삽목을 실시하였고, 15주간 근맹아 발생을 관찰하며 진행되었다. 그 결과, 24℃ 대조구는 4℃ 처리구에 비하여 총 근맹아 발생량이약 1.9배로 우수하였다. 처리구는 5주차까지 총 발생량의 95%가 발생하고 나서 8주차까지 총 2개가 추가 발생한 후 모든 발생이 멈췄다. 반면에 처리구에서는 5주차까지 총 발생량의 52%가 발생하였으며, 그 후 14주차까지 37개의 근맹아가 불규칙적으로 추가 발생하였다. 본 실험을 통하여 저온처리를 한 사시나무 근삽의 근맹아 발생이 대조구에 비해 조기에 멈추는 것을 확인하였다. 향후 사시나무의 근맹아 발생량을 높이기 위해서는 더욱 다양한 후속연구가 필요하다. Populus davidiana Dode is a fast growing species distributed mainly on the mountain area of East Asia. In Korea, it was an important planting species for management and greening during the early National Forest Plans. It is known to propagate well through root cutting because it is difficult to grow by stem cutting. Since the efficiency of obtaining clones is lower than that of stem cuttings, it is necessary to study to increase the productivity of root sucker in order to obtain a large number of individuals when attempting to multiply by using root cutting. For this reason, we were carried out this study to knowthe influence of low-temperature storage treatment on the generation efficiency of root sucker. Root cuttings were obtained from 9 clones including Odae19. In the experiment, the same samples were treated at 4℃ and 24℃ for 3 weeks, followed by root cutting in a greenhouse and observed for 15 weeks. As a result, the 24℃ control group was 1.9 times better than the 4℃ treatment group. In the initial amountof 2 weeks, however, treatment group 60% was higher compared to the control group 33.8%. In the treatment group, 95% of the total amount was generated until the 5th week, and then 2 more were added until the 8th. On the other hand, in the control group, 52% of total amount was generated until 5th week, and then root suckers 37 were irregularly added until the 15th. In this study, it was confirmed that the generation of root suckers of P. davidiana Dode with lowtemperature storage treatment stopped earlier than the control group. Further studies are needed to improve the generation amountof root suckers of P. davidiana Dode.

건물의 냉각탑 제어 변경에 따른 연간 냉방 에너지 사용량 절감에 관한 연구

하주완,박경순,김환용,송영학 한국건축친환경설비학회 2019 한국건축친환경설비학회 논문집 Vol.13 No.6

The purpose of this study is to find out the efficiency improvement of the cooling system and cut-off of cooling energy consumption by changing the design method of the cooling tower system applied in Korea. The quantitative analysis was carried out on the cooling energy consumption saved by changing the Korea Standard design temperature of cooling tower system through EnergyPlus simulation. As a result of the simulation, when the condenser water temperature difference from the existing cooling tower design standard is 5K to 7K, the annual cooling energy consumption is reduced by 27,084 kWh, approximately 7.6%. Also, additionally, when the condenser water leaving temperature form the existing cooling tower design standard is 32°C to 23.9°C according to ASHRAE 90.1, the annual cooling energy consumption was reduced by 59.419 kWh, and approximately 16.7%.

마이크로 금형 부품을 위한 마이크로 절삭가공 기술

하석재,박정연,김건희,윤길상 한국금형공학회 2019 한국금형공학회지 Vol.13 No.1

In this paper, we studied the micro tool deflection, micro cutting with low temperature, and deformation of micro ribs caused by cutting forces. First, we performed an integrated machining error compensation method based on captured images of tool deflection shapes in micro cutting process. In micro cutting process, micro tool deflection generates very serious problems in contrast to macro tool deflection. To get the real images of micro tool deflection, it is possible to estimate tool deflection in cutting conditions modeled and to compensate for machining errors using an iterative algorithm correcting tool path. Second, in macro cutting fields, the cryogenic cutting process has been applied to cut the refractory metal but, the serious problem may be generated in micro cutting fields by the cryogenic environment. However, if the proper low temperature is applied to micro cutting area, the cooling effect of cutting heat is expected. Such effect can make the reduction of tool wear and burr formation. For verifying this passibility, the micro cutting experiment at low temperature was performed and SEM images were analyzed. Third, the micro pattern was deformed by the cutting forces and the shape error occurred in the sidewall multi-step cutting process were minimized. As the results, the relationship between the cutting conditions and the deformation of micro-structure during micro cutting process was investigated.

Investigation on the Effect of Low Temperature Micro Cutting Process for Mold Core Material

Kim, Gun-Hee,Yoon, Gil-Sang,Son, Jong-In,Cho, Myeong-Woo 한국정밀공학회 2012 International Journal of Precision Engineering and Vol.13 No.5

Generally, micro cutting process has much higher specific cutting energy and more vulnerable tool volumes and strength compared to conventional cutting process. Besides, these characteristics of micro cutting processes which make much more tool wear and burr occur due to the cutting heat generated during processing greatly deteriorate the quality of cutting feature. In this study, the low temperature micro cutting process was proposed that can secure favorable the quality of micro cutting features by the tool wear reduction and cutting heat cooling and micro cutting experiments were performed under various cutting lubrication conditions. In order to analyze the characteristics of processing by cutting lubrication condition, cutting force monitoring using tool dynamometer, FFT analysis of micro cutting force data, the analysis of tool wear images and the SEM images analysis of fabricated micro slot feature were conducted. Finally, the efficiency of proposed micro cutting process was verified by the total results of abovementioned analysis processes.

Investigation on the Effect of Low Temperature Micro Cutting Process for Mold Core Material

김건희,윤길상,손종인,조명우 한국정밀공학회 2012 International Journal of Precision Engineering and Vol. No.

Generally, micro cutting process has much higher specific cutting energy and more vulnerable tool volumes and strength compared to conventional cutting process. Besides, these characteristics of micro cutting processes which make much more tool wear and burr occur due to the cutting heat generated during processing greatly deteriorate the quality of cutting feature. In this study, the low temperature micro cutting process was proposed that can secure favorable the quality of micro cutting features by the tool wear reduction and cutting heat cooling and micro cutting experiments were performed under various cutting lubrication conditions. In order to analyze the characteristics of processing by cutting lubrication condition,cutting force monitoring using tool dynamometer, FFT analysis of micro cutting force data, the analysis of tool wear images and the SEM images analysis of fabricated micro slot feature were conducted. Finally, the efficiency of proposed micro cutting process was verified by the total results of abovementioned analysis processes.

금형코어 재료의 저온 마이크로 절삭 가공시 버 발생 특성에 관한 연구

김건희(G. H. Kim),손종인(J. I. Sohn),윤길상(G. S. Yoon),이성희(S. H. Lee),허영무(Y. M. Heo),조명우(M. W. Cho) 한국생산제조학회 2009 한국공작기계학회 추계학술대회논문집 Vol.2009 No.-

In this study, a research on the micro cutting process with the mold core material at low temperature environment was performed. In macro cutting fields, the cryogenic cutting process, mainly turning process, has been applied to cut the refractory metal but, the serious problems may be generated in micro cutting fields by the cryogenic condition. However, if the proper low temperature is applied to micro cutting area, the cooling effect of cutting heat is expected. Such effect can make the reduction of tool wear and burr formation, For verifying this process, the micro cutting experiment at low temperature was performed and SEM images were analyzed.

금형코어 재료의 저온 마이크로 절삭 가공시 버 발생 특성에 관한 연구

김건희(G. H. Kim),손종인(J. I. Sohn),윤길상(G. S. Yoon),이성희(S. H. Lee),허영무(Y. M. Heo),조명우(M. W. Cho) 한국생산제조학회 2009 한국생산제조시스템학회 학술발표대회 논문집 Vol.2009 No.10

In this study, a research on the micro cutting process with the mold core material at low temperature environment was performed. In macro cutting fields, the cryogenic cutting process, mainly turning process, has been applied to cut the refractory metal but, the serious problems may be generated in micro cutting fields by the cryogenic condition. However, if the proper low temperature is applied to micro cutting area, the cooling effect of cutting heat is expected. Such effect can make the reduction of tool wear and burr formation, For verifying this process, the micro cutting experiment at low temperature was performed and SEM images were analyzed.

철계 금속 마이크로 절삭 가공시 저온 환경에서의 버 발생에 관한 기초연구

김건희(G. H. Kim),김동준(D. J. Kim),손종인(J. I. Sohn),윤길상(G. S. Yoon),허영무(Y. M. Heo),조명우(M. W. Cho) 한국소성·가공학회 2009 소성가공 : 한국소성가공학회지 Vol.18 No.2

In this paper, a basic study on micro cutting process with SM20C at low temperature environment was performed. In macro cutting fields, the cryogenic cutting process has been applied to cut the refractory metal but, the serious problem may be generated in micro cutting fields by the cryogenic environment. However, if the proper low temperature is applied to micro cutting area, the cooling effect of cutting heat is expected. Such effect can make the reduction of tool wear and burr formation. For verifying this possibility, the micro cutting experiment at low temperature was performed and SEM images were analyzed.

Evaluation of microbiological quality and safety of fresh-cut fruit products at retail levels in Korea

장아라,한아름,이소율,조수영,송하나,김단비,이선영 한국식품과학회 2021 Food Science and Biotechnology Vol.30 No.10

The risk of foodborne illnesses caused bypathogens could be increased in fresh-cut fruit productsowing to contamination during processing. Therefore, thisstudy was conducted to investigate the microbiologicalquality and safety of commercial fresh-cut fruit products inKorea. Additionally, the growth of Listeria monocytogenesin selected fresh-cut fruits was evaluated, and their growthcurves were analyzed using predictive growth modeling. The mean count of total aerobic bacteria, coliforms, andyeast/mold was 3.67±1.73 log10 CFU/g, 1.54±1.01 log10CFU/g, and 3.81±1.51 log10 CFU/g, respectively. Escherichia coli, Staphylococcus aureus, Escherichia coliO157:H7, L. monocytogenes, Salmonella spp., and Cyclosporaspp. were not detected in any of the testedsamples. Only Bacillus cereus was detected in a few samplesat the mean level of 1.72±0.13 log10 CFU/g. Thegrowth of L. monocytogenes varied depending on the typeof fruit; they grew well in non-acidic fresh-cut fruit productsduring storage at 10 °C.