• 한국식품저장유통학회:학술대회논문집
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• 한국식품저장유통학회 1993년도 정기총회 및 제3차 학술발표회
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• pp.6-9
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• 1993

According to changes in population, economic conditions, life-stile and eating habits, the frui ts and vegetables market wi 11 be shi fted from processed (i. e. , canned) to fresh. Undressed fresh produce, consisting of washed, disinfected and peeled fruits and vegetables that either sliced or grated, are currently increased in demand by retail and institutional market which use them as salad components or in ready-to use foods, Main attributes of minimally processed fruits and vegetables are convenience and fresh-like quality. Minimally processed Products readily deteriorate in quality, especially color and texture, as a result of endogeneous enzyme enhanced respiration and microorganisms which lead to reduced shelf Iife. According to changes in population, economic conditions, life-stile and eating habits, the frui ts and vegetables market wi 11 be shi fted from processed (i. e. , canned) to fresh. Undressed fresh produce, consisting of washed, disinfected and peeled fruits and vegetables that either sliced or grated, are currently increased in demand by retail and institutional market which use them as salad components or in ready-to use foods, Main attributes of minimally processed fruits and vegetables are convenience and fresh-like quality. Minimally processed Products readily deteriorate in quality, especially color and texture, as a result of endogeneous enzyme enhanced respiration and microorganisms which lead to reduced shelf Iife. Thus. to prevent these undesirable changes , val'ious techniques such as controlled atmosphere (CA) storage, modified atmosphere OIA) storage, including vacuum packaging have been receiving considerable attention, Although milch research has been done to find optimal conditions for whole intact frui ts and vegetables, only limi ted information is avai lable on fresh cut. and other minimally processed products. 81 iced frui ts exhibi t increas~d ethylene production and respiration compal'ed to whole f, 'uits during distribution in response to tissue damage. As a result, accelerated senescence and enzymatic browning OCCUI', Recent l'esearch on minimally processed fl'uits and vegetables has mainly focused on methods to inhibit browning, due to ban on use of sulfur dioxide, In order to retard or prevent these physiological changes, val'ious al ternatives, reducing agents. acidulants, chelating agents and inol'ganic sal ts have been evaluated for use on fresh cut fl'ui ts. Al though some agents were effective replacement for sulfur dioxide. consum$\textregistered$I'S demandless use of chemical on such products. Shel~ life of minimally processed products has been extended by inhibition of metabolic reactions associated with loss of quality and by inhibition of aerobic spoilage caused by wide variety of microorganisms. Appl ication of ~I.-\ packaging, including vacuum packaging, retards the rate of respiration, prevents growth of aerobic spoilage organisms, inhibits oxidation and color deterioration. Tissue softening is another major problem in minimally processed products because enzymes re 1 a ted to ce 11 wa 11 degrada t i on are not inactivated. Various treatments have been investigated for retardation of the softening of sliced products. Some studies have concentrated on the application of an active packaging system with ~I, l. packaging and calcium infi 1 tration as possible measures to retain firmness of processed products. In my opinion, one important step for production of minimally processed frui ts wi th favorabl e color of cut surface and firm texture is the selection of better cultivar. As the view, changing tendency of fresh color by apple cultivars and relationship between the tendency and PPO activity will be discussed in the seminar. In addition to the topic, research result on quality enhancement of fresh apple slices by heat shock treatment will be introduced.

• 마이크로전자및패키징학회지
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• 제24권4호
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• pp.31-37
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• 2017

최근, 유연하며 몸에 부착 가능한 소자들에 대한 관심이 늘어나고 있다. 이런 관심을 뒷받침 하여 이와 관련된 다양한 연구들이 진행되고 있는데, 기존 딱딱한 성질을 가진 소자에 사용되던 무기물 기반의 재료의 경우 유연 소자로 만들기에 여러 가지 제약이 있어 유연하게 제작할 수 있는 유기물 반도체나 탄소 나노튜브 필름 등을 이용한 소자들이 주로 연구되고 개발되어 왔다. 하지만 이런 재료들을 이용한 소자의 경우 유기물 분자와 분자 사이 또는 탄소 나노튜브와 나노튜브 사이에서 전하들이 산란되는 등 재료 자체의 한계로 인해 기존의 재료를 사용한 소자들보다 전기적 성능이 떨어지는 단점을 가지고 있다. 이런 단점들을 해결하기 위하여 이 연구에서는 수직 정렬된 반도체 결정 어레이를 투명 유연한 폴리머와 결합하는 방법을 이용, 고품질 나노/마이크로 반도체 결정을 유연한 기판으로 전사 시킬 수 있는 방법을 제시한다. 위와 같은 구조는 재료에 가해지는 힘을 완화 시켜줄 수 있으며, 이로 인해 큰 변형에도 재료의 손상이 없는 소자 제작이 가능하다. 이런 구조를 구현하기 위해 위치 및 크기가 정교하게 제어된 ZnO 나노막대 단결정을 저온에서 용액공정을 통하여 합성시킨다. 이후 성장시킨 ZnO 단결정 어레이와 polydimethylsiloxane (PDMS) 폴리머를 결합시킨 후 단단한 기판에서 기계적으로 박리시켜 ZnO/폴리머 복합체를 분리해 낸다. 추가적으로 전사된 ZnO의 결정성을 확인하기 위하여 photoluminescent 분석을 진행하였으며, ZnO/폴리머 복합체를 이용한 외부 힘에 반응하는 압력 센서를 제작하였다.

• 마이크로전자및패키징학회지
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• 제21권4호
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• pp.105-110
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• 2014

재생에너지 광소자로서 스마트 농장 등의 에너지원으로서 고분자 태양전지의 응용이 기대되며 향후 상업화를 위해 효율과 신뢰성 개선이 요구된다. 본 연구에서는 유기 패시베이션 박막을 가지는 헤테로정션 고분자태 전지를 제작하고, 패시베이션 박막이 고분자 태양전지의 특성에 미치는 영향을 조사하였다. 사용된 패시베이션 유기재료로는 폴리비닐알코올과 이크롬산 암모늄을 혼합하여 용해한 후 스핀코팅방법으로 P3HT:$PC_{61}BM$/LiF/Al 기판위에 코팅하여 소자를 제작하였다. 제작된 소자구조는 glass/ITO/PEDOT:PSS/P3HT:$PC_{61}BM$/LiF/Al/passivation layer 이며, 140시간 공기 중에 노출 후 전기적 특성을 측정, 비교한 결과, 패시베이션 처리된 고분자 태양전지가 패시베이션 박막 처리되지 않은 소자에 비해 보다 우수한 전기적 특성을 보여주었다. 즉, 패시베이션 처리된 소자의 전력변환효율은 제작직후 3.0%에서 140시간 노출 후 1.3%로 감소한 반면 패시베이션 처리되지 않은 소자의 경우는 동일한 노출조건에서 3.5%에서 0.1%로 급격한 특성저하를 나타내었다.

• 마이크로전자및패키징학회지
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• 제17권2호
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• pp.63-67
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• 2010

본 연구에서는 P3HT와 PCBM 물질을 전자도너와 억셉터 광활성층 물질로 사용하여 벌크이종접합 구조를 갖는 Glass/ITO/PEDOT:PSS/P3HT-PCBM/Al 구조의 유기박막태양전지를 제작하였다. P3HT와 PCBM은 각각 0.5 wt%의 농도로 톨루엔 용액에 용해하였다. 광활성층 농도를 최적화하기 위하여 P3HT:PCBM= 3:4, 4:4, 4:3 wt%의 농도비로 소자를 제작하고, 농도비에 따른 전기적 특성을 조사하였다. 또한 활성층의 후속열처리 온도가 소자의 전기적 특성에 미치는 영향을 조사하였다. P3HT와 PCBM의 농도비가 4:4 wt%의 비율에서 가장 우수한 전기적 특성을 나타내었으며, 이때 단락전류밀도 ($J_{SC}$), 개방전압 ($V_{OC}$), 및 충실인자 (FF)는 4.7 $mA/cm^2$, 0.48 V 및 43.1%를 각각 나타내었다. 또한 전력변환효율(PCE)은 0.97%의 값을 얻었다. 최적화된 농도비를 갖는 태양전지 소자에 대해 $150^{\circ}C$에서 5분, 10분, 15분, 20분간 후속 열처리를 실시한 결과 P3HT 전자도너의 흡광계수가 증가하는 경향을 보였다. 후속 열처리 조건이 $150^{\circ}C$에서 15분인 경우 전기적 특성이 열처리 하지 않은 소자에 비해 특성이 개선되었다. 즉, 이때의 전기적 특성은 $J_{SC},\;V_{OC}$, FF, PCE의 값이 각각 7.8 $mA/cm^2$, 0.55 V, 47%, 2.0%를 나타내었다.

• 한국버섯학회지
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• 제16권3호
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• pp.131-139
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• 2018

큰느타리버섯은 에르고스테롤 및 글루칸과 같은 기능성 물질의 함량이 높아 항산화 활성 및 프리바이오틱 효과를 일으키는 버섯이다. 큰느타리버섯은 향이 강하며 단단해 기호도가 높지만 장기간 소요되는 선박수출 등에서는 선도유지 기간 확보가 필요하다. 버섯의 품질에 영향을 미치는 외부요인은 온도, 상대습도, 공기조성 및 통풍 상태가 있으며 이로 인해 버섯의 호흡량, 수분 함량, 경도, 색도, pH 및 이취 등에 영향을 준다. 큰느타리버섯의 주요 장해는 갈변, 이취, 부패가 있으며, 이를 막기 위해 상품성이 높은 품종을 개발하거나 저장성을 높이는 처리 방법이 고안되고 있다. 버섯의 품질을 유지하기 위한 방법으로는 건조, 감마선 조사, 키토산 처리와 같은 수확 후 처리 방법과 CA 저장과 MA 포장을 통한 저장 방법이 있다. 버섯의 건조는 자연건조, 열풍건조, 동결건조, 진공건조, 전자파진공건조 방법이 있으며 동결건조 방법을 사용한 버섯의 성분저하가 비교적 낮았다. 1 kGy 감마선 조사가 고선량에 비해 저장기간 연장에 효과적이었으며 오일, protocatechuic acid, 왁스 등의 친수성 colloid를 키토산에 첨가하여 코팅처리 하였을 때 경도유지, 호흡 및 갈변이 억제되었다. 큰느타리버섯의 CA 저장조건은 $10^{\circ}C$ 이하의 온도에서 5kPa $O_2$ + 10~15kPa $CO_2$의 공기 조성이 제시되었으며 MA 포장으로는 미세천공을 갖는 PP필름을 이용한 능동적 기체조성 방법이 저장 중 품질유지에 효과적이었다.

• 한국식품영양과학회지
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• 제45권5호
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• pp.778-781
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• 2016

본 연구에서는 폐기되는 성게 껍질을 이용한 생분해성 필름소재를 개발하고자 gelatin을 첨가한 복합필름 및 항산화, 항균성을 부여하기 위해 아까시 꽃 추출물(RFE)을 첨가한 필름을 제조하였다. 그 결과 gelatin 비율이 증가함에 따라 성게 껍질 필름의 인장강도가 증가하였고 신장률이 감소하였으며, 성게 껍질과 gelatin을 8:2 비율로 첨가하였을 때 최적의 물성을 보였다. 또한, 필름에 RFE를 첨가함에 따라 인장강도는 감소하였으나 신장률과 필름 투습도는 증가하였다. RFE 함유 성게 껍질 필름의 ABTS, DPPH 라디칼 소거능 측정과 디스크 확산법을 이용하여 항산화 및 항균 능력을 측정하였는데, RFE 농도가 증가함에 따라 항산화, 항균 능력이 향상하였다. 따라서 본 연구 결과, RFE를 첨가한 생분해 성게 껍질 필름은 적절한 물성과 함께 항산화, 항균 능력이 있기에 가공식품의 저장성을 증대시킬 수 있는 기능성 포장 소재로의 활용이 가능하다고 판단된다.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2011년도 춘계학술발표대회
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• pp.3.1-3.1
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• 2011

Over the past decade, the major efforts for lowering the cost of electronics has been devoted to increasing the packaging efficiency of the integrated circuits (ICs), which is defined by the ratio of all devices on system-level board compared to the area of the board, and to working on a larger but cheaper substrates. Especially, in flexible electronics, the latter has been the favorable way along with using novel nanomaterials that have excellent mechanical flexibility and electrical properties as active channel materials and conductive films. Here, the tool for achieving large area patterning is by printing methods. Although diverse printing methods have been investigated to produce highly-aligned structures of the nanomaterials with desired patterns, many require laborious processes that need to be further optimized for practical applications, showing a clear limit to the design of the nanomaterial patterns in a large scale assembly. Here, we demonstrate the alignment of highly ordered and dense silicon (Si) NW arrays to anisotropically etched micro-engraved structures using a simple evaporation process. During evaporation, entropic attraction combined with the internal flow of the NW solution induced the alignment of NWs at the corners of pre-defined structures. The assembly characteristics of the NWs were highly dependent on the polarity of the NW solutions. After complete evaporation, the aligned NW arrays were subsequently transferred onto a flexible substrate with 95% selectivity using a direct gravure printing technique. As proof-of-concept, flexible back-gated NW field effect transistors (FETs) were fabricated. The fabricated FETs had an effective hole mobility of 0.17 $cm2/V{\cdot}s$ and an on/off ratio of ${\sim}1.4{\times}104$. These results demonstrate that our NW gravure printing technique is a simple and effective method that can be used to fabricate high-performance flexible electronics based on inorganic materials.

• 무역상무연구
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• 제75권
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• pp.179-198
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• 2017

Recently, agricultural exports of Korea have steadily increased. But, no progress is being made at the WTO and DDA negotiations, the FTAs have played a leading role in the formulation of the international trade rules, and countries have been cleverly utilizing non-tariff barriers such as SPS and TBT, there is a growing need to respond to non-tariff barriers aggressively. On the other hand, since the FTA has the potential to activate the global value chain, there is a high need for exporting companies in the domestic agricultural sector to understand the structure of the global value chain in agriculture and actively utilize the global value chain. The non-tariff measures of agricultural commodities major trading partners in the field of domestic agricultural exports were mostly comprised of SPS measures and TBT measures. The non-tariff measures corresponding to inputs and production stages of value chain elements (seeds, seedlings) in the value chain were mainly reported in SPS measures. TBT measures are mainly carried out in selective packaging, storage, processing, distribution, and export sales. It is most important for agricultural export companies to know their position on the value chain and information on non-tariff measures of importing countries in order to actively utilize the global value chain. Since there are non-tariff barriers that are difficult to be solved at the individual enterprise level, active government support of the government is not only important but also actively promoting relevant information to farmers and agricultural exporters. In addition, potential export farmers and prospective export companies will be able to identify TBT and SPS and other non-tariff barriers well in advance, and respond to them in advance. Also, through networking with export related organizations and overseas buyers, It is very important that policy support from the perspective of global value chain is linked effectively.

• Journal of Microbiology and Biotechnology
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• 제28권7호
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• pp.1185-1198
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• 2018

The nucleosomal organization of chromatin using histone proteins is a fundamental and ubiquitous feature of eukaryotic nuclei, with the major exception of dinoflagellates. Although a number of recent genomic and transcriptomic analyses have detected numerous histone genes in dinoflagellates, little is known about their expression. Here in, we aimed to investigate the expression pattern of histone genes under nutritional stress, and an attempt was made to detect histone expression at the protein level in Alexandrium pacificum. The presence of histones at the mRNA level was confirmed in this study by the amplification, cloning, and sequencing of 10 different genes. Relative expression profiling of these genes under different growth conditions was determined with real-time PCR and revealed considerable levels of histone transcription in nutritionally stressed cells. We were unable to detect the expression of histones at the protein level even after immunodetection and analysis using mass spectrometry, although a histone-like protein was detected as a major nuclear component. A. pacificum expresses multiple variants of histone, and protein sequences revealed both conservation and divergence with respect to other eukaryotes. We concluded that A. pacificum maintained an active transcription of histone genes within the cell, and enhanced expression of histone genes in nutritional stress strongly suggest that histones have functional significance in dinoflagellates, although expression at the protein level was below our current detection limits, which suggests a limited role of histones in DNA packaging. Finally, the plausible regulation of histone expression at the gene and protein levels in A. pacificum is discussed.

• 한국식품저장유통학회지
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• 제31권1호
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• pp.1-14
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• 2024

The utilization of coatings composed of bio-based materials in the processing and preservation of meat presents an environmentally conscious, secure, cost-effective, and superior method for prolonging the storage life of meat while also preserving its nutritional value. In this study, changes in physical, chemical, and microbiological characteristics of freshly cut beef coated with distilled water (control) and keratin-starch composites (K-S) functionalized with 0.0-, 0.2-, 0.6-, and 1.0-mL avocado peel polyphenolic-rich extract (APPPE) kept at 4℃ for 12 days were evaluated periodically at 3-day interval using standard techniques. Keratin was extracted from waste feathers, while starch was obtained from ginger rhizomes. Following a 12-day storage period, beef coated with APPPE-enriched K-S composites exhibited a significant (p<0.05) improvement in shelf life by minimizing deteriorative changes in pH and color (as determined by metmyoglobin level) in addition to inhibiting oxidative changes in lipids (as determined by TBARS level) and proteins (protein carbonyl level) in comparison to control and K-S composite without APPPE. Furthermore, microbial growth was significantly (p<0.05) suppressed in meat coated with K-S composite functionalized with APE at 0.6 and 1.0 mL compared to the control. The study suggested that APPPE-enriched K-S composite could offer an eco-friendly and safe food preservation technique for fresh meat.