• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2008년 영문 학술대회
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• pp.283-292
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• 2008

The foremost criterion in the design of a Satellite Launch Vehicle(SLV) is its performance capability to boost the designated payload to the desired mission orbit; it starts from focusing on the SLV configuration to achieve the velocity requirements($}\Delta}V$) for the mission. In this paper we review an analytical approach which is suitable enough for preliminary conceptual design and is used previously to optimize stage configurations for Two Stage to Orbit SLV for Low Earth Orbit(LEO) Missions; we have extended this approach to Three Stage to Orbit SLV and compared different propellant options for the mission. The objective is to minimize the Gross Lift off Weight(GLOW). The primary performance figures of merit were the total inert weight of the SLV and the payload weight that the SLV could lift into LEO, given candidate propulsion systems. The optimization is achieved by configuring the $}\Delta}V$ between stages. A comparison of configurations of single-stage and multi-stage SLVs is made for different propellants. Based upon the optimized stage configurations a comparative performance analysis is made between Liquid and Solid fueled SLV. A 3 degree of freedom trajectory-analysis program is modeled in SIMULINK and used to conduct the performance analysis. Furthermore, a cost analysis is performed on our stage optimized SLVs. The cost estimation relationships(CER) used give us a comparison of development and fabrication costs for the Liquid vs. Solid fueled SLV in man years. The pros and cons of the production, operation ability, performance, responsiveness, logistics, price, shelf life, storage etc of both Solid and Liquid fueled SLVs are discussed. The statistics and data are used from existing or historical(real) SLV stages.

• 한국추진공학회지
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• 제22권1호
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• pp.66-71
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• 2018

에너지 물질의 수명평가는 중요하게 여겨지지만, 여러 가지 어려움을 갖고 있다. 먼저 노화시험에 매우 긴 시간이 소요되고, 에너지 물질이기 때문에 취급 시 항상 위험이 존재한다. 이런 이유들로 인해서 예측이나 계산 방법들이 발달되어 왔다. 에너지 물질은 열을 내놓으면서 분해되기 때문에, 에너지 물질의 열적 특성을 분석하는 것은 에너지 물질의 분해와 노화 특성을 이해하는데 매우 중요하다. 이번 연구에서는 첫째, DSC를 기초데이터로 하여 AKTS software를 이용하여 간단한 열분석으로부터 열적인 노화 특성을 예측하는 결과들을 발표하고, 둘째, AKTS software를 통해 물성측정 점 데이터로부터 적절한 kinetic 모델을 설정하고, 그 모델로부터 노화에 따른 특성변화를 예측하는 결과를 나타내었다.

• 융합정보논문지
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• 제9권12호
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• pp.166-174
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• 2019

본 연구는 토복령 추출물의 항산화 활성 및 저장성 증진 가능성을 보고자 돼지 갈비소스의 5주간의 품질변화를 조사하였다. 저장 4주째에 총 균수는 대조군과 0.25% 첨가군에서 0.5%와 0.75% 첨가군에 비해 높은 수치를 나타내어, 토복령 추출물 첨가량이 많아질수록 총 균수는 낮아짐을 알 수 있었다. DPPH 라디컬 소거 활성은 첨가량이 많아질수록 증가하였으며, 토복령 추출물 0.75% 첨가군은 유의적으로 높은 소거 활성을 나타내었다(p<0.05). 또한, 토복령 추출물 첨가량이 증가할수록 TBARS는 낮아졌으며, 0.5%와 0.75% 첨가군은 유의적으로 낮은 수치를 보였다(p<0.05). 본 실험 결과로 토복령 추출물의 항산화 활성을 통한 기능성 향상과 항균 효과에 의한 저장성 강화로 식품 첨가 보존제로서의 개발 가능성이 있을 것으로 사료된다.

• 한국식품저장유통학회지
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• 제18권3호
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• pp.279-287
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• 2011

The purpose of this research is to develop bellflower (Platycodon grandiforum) root Jeonggwa as a health food. The Omija (Schizandra chinensis Baillon) water extract with 0-8% (w/w) Jeonggwa added was stored at $25^{\circ}C$ for 12 weeks. The quality characteristics of Jeonggwa during storage were investigated. The Jeonggwa showed a lower pH and a higher acdity as the amount of Omija water extract that was added increased. The moisture content of Jeonggwa were rose from 15-18% to 16-22% within 2 weeks of storage, and remained at that level up to the end of storage. The total viable cells of bellflower root Jeonggwa were 2.1~2.3 log CFU/g and increased in number during storage but never exceeded 4 log CFU/g. The shelf life of the Jeonggwa was extended when the Omija extract was added. The lightness (L), redness (a) and yellowness (b) of the Jeonggwa during its storage at $25^{\circ}C$ were highest in control samples, and the values decreased with the increase in the Omija extract concentration (p<0.001). The mechanical evaluation of the Jeonggwa showed that various tested parameters fell during the storage at $25^{\circ}C$. The hardness and strength of the Jeonggwa significantly decreased as the Omija extract concentration rose (p<0.05). In the ensory evaluation tests, the acceptability of the Jeonggwa was optimal when 4~6% of Omija extract was added to it.

• 한국식품저장유통학회지
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• 제19권4호
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• pp.477-484
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• 2012

찹쌀떡의 경화 억제 및 저장성 개선을 위하여 대규모 떡 생산업체에서 실제 사용되고 있는 당류 및 유화제를 이용하여 저장 중 물성 변화를 조사하고자 하였다. 이때 유화제 및 당류의 첨가농도는 떡 생산업체에서 사용빈도가 높은 농도를 중심으로 설정하였다. 즉, 찹쌀떡에 첨가한 유화제는 에스피로 0.1, 0.5, 1%로 첨가하였고, 당류로는 설탕을 5, 10, 15%, 저당을 5, 10, 20%, 맥아당을 10, 15, 20%로 각각 첨가하여 찹쌀떡을 제조한 뒤 $4^{\circ}C$에 저장하면서 물성을 측정하였다. 그 결과, 에스피 첨가농도는 0.5%일때, 설탕 첨가농도는 15% 일때, 저당 첨가농도는 20%일때, 맥아당 첨가농도는 10% 일때 저장기간에 따른 물성 변화가 완만하게 일어나고 찹쌀떡의 경화 억제에 효과적인 것으로 나타났다.

• 한국잠사곤충학회지
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• 제53권2호
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• pp.101-109
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• 2015

본 연구는 장기 냉동저장 오디에 대해 현재 사용하고 있는 방법이 보관 및 유통비용 등이 커 농가에 부담이 되므로, 이에 고가 건조기를 대체할 수 있는 값이 저렴한 상용화된 다목적농산물건조기를 통한 건조기 개량 및 반건조기술을 개발하였다. 연료와 히터의 건조온도를 $60^{\circ}C$로 설정하고, 상온통풍은 상온보다 온도를 낮추어 건조시험 한 결과 연료 3시간, 히터 1시간, 상온통풍 51시간인 조건에서 다른 조건과 비교해서 연료소모 및 전기사용량 면에서 가장 양호하였고, 품질에 있어서도 다른 조건에 비해 현저히 끈기가 있는 반 건조 특성을 나타내었으며, 완료된 건조시료의 상태도 상품성이 뚜렷한 암갈색을 나타냈다. 경도(압축력)은 건조 전보다 건조 후에, 항온보다는 변온에서 높게 나타났다.

• 한국환경농학회지
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• 제40권3호
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• pp.179-185
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• 2021

BACKGROUND: Tomato genome editing using CRISPR-Cas9 is being actively conducted in recent days, and lots of plant researches have been aiming to develop high valued crops by editing target genes without inserting foreign genes. Many researchers have been involved in the manipulation of the crop ripening process because fruit ripening is an important fruit phenotype for increasing fruit shelf life, taste, and texture of crops. This paper intends to evaluate target sgRNA to edit the two ripening-related genes encoding pectate lyase (PL) and phytoene synthase (Psy) with the CRISPR-Cas9 system. METHODS AND RESULTS: The CRISPR-Cas9 expression vector was cloned to target the PL (Solyc03g111690), Psy1 (Solyc03g031860), and Psy2 (Solyc02g081330) genes, which are the ripening genes of tomatoes. Tomatoes injected with Agrobacterium containing the CRISPR-Cas9 expression vector were further cultured for 5 days and used to check gene editing efficiency. As a result of the target gene sequence analysis by the next generation sequencing method, gene editing efficiency was calculated, and the efficient target location was selected for the PL and Psy genes. CONCLUSION: Therefore, this study was aimed to establish target sgRNA data that could have higher efficiency of the CRISPR-Cas9 system to obtain the delayed ripening phenotype of tomato. The developed method and sgRNA information is expected to be utilized in the development of various crops to manage its ripening processes.

• Journal of Animal Science and Technology
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• 제61권1호
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• pp.28-34
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• 2019

Liver sausage is flavorful and highly nutritious. However, liver has a relatively short shelf life due to acceleration of oxidation in the presence of endogenous enzymes and metals. Powders derived from natural sources, including plants or fruits, are applied to meat products for inhibiting oxidation without adverse effects on their quality. Hence, this study investigated the effects of natural powders derived from green tea leaf (GTL), lotus leaf (LL), and kimchi (KC) on the quality and change in lipid oxidation and freshness of chicken liver sausages during two weeks of storage. Chicken liver sausages were manufactured with chicken breast (70%) and liver (20%), pork back fat (5%), iced water (5%), various additives, and GTL, LL, and KC [0 (control) or 1%]. They were processed in three batches. For determination of the quality characteristics of chicken liver sausages with various plant powders, pH, color, and texture properties were assessed. In addition, lipid oxidation and freshness using thiobarbituric acid reactive substances (TBARS) and total volatile basic nitrogen (TVBN) were analyzed at day 0 and week 2 of refrigerated storage. Higher values were obtained for pH and cooking yield in sausage samples with LL and KC powders than in samples with the other treatments. For a* values, the sausage samples with KC showed similar (p > 0.05) values, whilst others had significantly lower values than the control. The addition of the three powders to sausage samples induced an increase (p < 0.05) in hardness, gumminess, and chewiness. The addition of plant powders did not influence TBARS and TVBN of sausage samples at the initial stage. However, after two weeks of storage, significantly lower TBARS and TVBN values were observed, and the sausage with KC (p < 0.05) showed the lowest values of both TBARS and TVBN. The results showed the potential ability of the three powders to improve the quality and inhibit lipid oxidation in liver sausages. Particularly, the addition of KC did not adversely affect the $a^*$ values of sausage samples. The effects on sensory properties and inhibition mechanisms of GTL, LL, and KC in meat products should be further studied.

• 농업과학연구
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• 제45권4호
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• pp.811-821
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• 2018

This study focused on the improvement of blueberry delivery service using pre-cooled ice and $SO_2$ pads to prevent an increase in the fruit temperature as well as decay. To maintain the fruit quality during low temperature storage, the effect of a $SO_2$ pad and modified atmosphere packaging was also examined. Harvested blueberries were precooled at $15^{\circ}C$, sorted, and packaged. And the fruits were placed in a similar environment as that for the parcel service. Part of the fruits were stored at $0^{\circ}C$ for long term storage. The air temperature in the delivery box increased along with an increase in the simulated delivery time regardless of the treatment. However, the rate of temperature increase was lower in the ice pad treatment. No significant difference was not found after 48 h. The oxygen concentration in the box ranged between 10.5 - 14.5% in the ice pad treatment, which was higher than that of the untreated control (7.5 - 11.9%) whereas the $CO_2$ concentration was lower in the ice pad treatment. No differences were found in the occurrence of off-flavor, decay, and sensory quality loss during the 48 hours of the parcel service simulation. The combined treatment of the $SO_2$ pad and modified atmosphere packaging (MAP) using a perforated film increased the shelf-life of the blueberry fruits, the overall quality such as firmness, and the soluble solid content was not different between the treatments except for the decay incidence. No decayed fruit was found in the combined treatment. However, the percentage of decayed fruit in the control was 25% on day 15 of storage and 75% on day 33 of storage, respectively.

• Asian-Australasian Journal of Animal Sciences
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• 제32권2호
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• pp.265-273
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• 2019

Objective: Terminalia arjuna plant, specially its leaves, bark, and roots, are widely used in traditional herbal medicine due to presence of bioactive components and being a rich source of natural antioxidants. But its fruit has not been used for any such purposes despite its potential to retard oxidation. Hence, the antioxidant potential of Arjuna fruit extract (AFE) in retarding lipid and protein oxidation of raw ground pork was evaluated during refrigerated storage for 9 days. Methods: The AFEs were prepared using different solvents viz. ethanol (EH), water, ethanol: water (60:40) and methanol:hot water (60:40). The AFEs were analysed for total phenolic content (TPC), 2, 2-diphenyl-1-picrylhydrazyl radical scavenging activity and reducing power. Water extract (WE) and ethanol-water extract (EH-WE) were selected and incorporated at 1.0% into freshly minced pork meat and compared with a synthetic antioxidant, in retarding lipid and protein oxidation during storage. Results: The TPC in AFEs using different solvents ranged from 11.04 to 16.53 mg gallic acid equivalents/g and extracts exhibited appreciable scavenging activity ranging from 50.02% to 58.62%. Arjuna extracts significantly (p<0.05) improved the colour score of meat samples by reducing the formation of metmyoglobin during storage. Both the AFEs (WE and EH-WE) significantly (p<0.05) lowered the thiobarbituric acid reactive substances value, peroxide formation and formation of protein carbonyls in raw pork than control sample during storage. Upon sensory evaluation of all samples, it was found that AFE treatment could prolong the storage period of meat samples, without influencing the colour and odour score, up to 6 days. Conclusion: AFEs used at 1% improved the oxidative stability, colour and odour score and prolonged the refrigerated shelf life of ground pork up 6 days. Therefore, AFE could be explored as an alternative natural antioxidant in retarding lipid and protein oxidation in meat products.