• 한국식품영양학회지
• /
• 제11권4호
• /
• pp.452-459
• /
• 1998

In 7 kinds of Gulbi purchansed from Yosu, Sunchon and Chinju, N-nitrosamine (NA) such as N-nitrosodimethylamine (NDMA), N-nitrosodiethylamine (NDEA) and N-nitrosodipropylamine(NDPA), were detected and their content was 2.8∼78.3$\mu\textrm{g}$/kg, trace and 0∼1.4$\mu\textrm{g}$/kg, respectively. This experiment was conducted to study the effect of processing conditions on NA formation in the salted and dried yellow corvenia(Guibi), prepared by using the different salting method like dry and brine salting by pure and crude salt. NDMA, NDEA and NDPA were not detected in raw sample, but NDMA content increased in yellow corvenia during its salting (27.6∼37.4$\mu\textrm{g}$/kg), and then drastically decreased in Gulbi stored for 40 days, ranging from 2.8 to 4.3$\mu\textrm{g}$/kg. Content of above NA was inhibited more effectively in the samples prepare with brine salting method than with the dry salting method during its processing and storage. Especially, NA in the sample prepared with brine salted and dried yellow corvenia using the pure salt was detected in the lower concentrations, and that of NDMA, NDEA and NDPA was 2.8∼27.6, trance and ND-2.7$\mu\textrm{g}$/kg, respectively.

• 한국지하수토양환경학회지:지하수토양환경
• /
• 제29권1호
• /
• pp.1-9
• /
• 2024

As part of monitoring technology aimed at verifying the stability of CO₂ geologic storage and mitigating concerns about leakage, a method for measuring the pH and alkalinity of high-pressure fluid samples was established to obtain practical technology. pH measurement for high-pressure samples utilized a high-pressure pH electrode, and alkalinity was measured using the Gran titration method for samples collected with a piston cylinder sampler (PCS). Experimental samples, referencing CO₂-rich water and CO₂ geologic storage studies, were prepared in the laboratory. The PCS controls the piston, preventing CO₂ degassing and maintaining fluid pressure, allowing mixing with KOH to fix dissolved CO₂. Results showed a 6.1% average error in high-pressure pH measurement. PCS use for sample collection maintained pressure, preventing CO₂ degassing. However, PCS-collected sample alkalinity measurements had larger errors than non-PCS measurements, limiting PCS practicality in monitoring field settings. Nevertheless, PCS could find utility in preprocessing for carbon isotope analysis and other applications. This research not only contributes to the field of CCS monitoring but also suggests potential applications in studies related to natural analogs of CCS, CO₂-rock interaction experiments, core flooding experiments, and beyond.

• 생명과학회지
• /
• 제24권12호
• /
• pp.1325-1329
• /
• 2014

건강 기능성 한방 재료로 알려져 있는 구기자를 식품 재료로 이용하기 위해서는 건조 구기자가 오래되면 생성되는 이취 성분이 문제가 된다. 구기자중 저장 기간이 짧은 것(시료1)과 저장 기간이 오래 된 것(시료2)에 대해 휘발성 성분을 비교 분석하여 이취를 찾고 추후 이취를 제거하는 방법을 모색하기 위해 연구를 시행하였다. 각 구기자 시료에 대해서 동시증류추출장치(SDE)를 사용하여 휘발성 성분을 추출하고 GC-MS로 분석, 동정하였다. 시료1의 휘발성성분으로 aldehyde류 17종, alcohol류 8종, terpene류 6종, ester류 4종, ketone류 3종 및 furan류 3종, pyrazine류 3종 및 기타 2종을 포함한 총 45종의 향기성분을 동정하였다. 시료2의 휘발성성분으로 aldehyde류 12종, alcohol류 3종, terpene류 5종, ester류 2종, ketone류 4종, furan류 3종, pyrazine류 3종, 산인 isovaleric acid 1종 및 기타 2종을 포함한 총 34종의 향기성분을 동정하였다. 두 시료 중에서 휘발성 성분의 차이가 있었다. 이러한 휘발성 성분의 차이와 함량의 변화는 구기자의 저장 기간이 길어지면 좋지 않은 냄새에 영향을 미친다고 생각되지만 저장 기간이 짧은 구기자에는 없고 저장기간이 오래 된 구기자에만 동정된 역치가 매우 낮은 isovaleric acid은 구기자 제품의 저장성이 경과할 때 영향을 줄 것으로 생각되었다.

• 한국수산과학회지
• /
• 제10권4호
• /
• pp.221-226
• /
• 1977

동결저장중 옥돔의 상품가치의 유지와 선도유지기간의 연장에 대한 BHA 및 polyposphate의 처리효과에 대한 실험 결과를 요약하면 다음과 같다. 1) 염가용성 단백질은 동결저장온도에 따라 용출도에 차이가 있었으나, 약품처리에 따른 용출도의 차이는 없었다. 2) 유리수의 유출량은 동결저장기간중 저장온도에 따라 현저한 차이가 있었고, sodium polyphosphate 처리한 것이 유리수 유출량이 적었다. 3) 휘발성 염기실소의 량은 저장온도에 따라 현저한 차이가 있으나, 약품처리에 따른 차이는 거의 없었다. 4) TBA값은 저장온도에 따라 현저한 차이가 있었고, sodium polyphosphate 처리한 것이 BHA 처리한 것보다 6개월 저장 후에도 약간 낮았다. 5) carotene 변화 역시 저장염도에 따라 현저한 차이가 있으며, 특히 $-5^{\circ}C$저장에서는 3개월 저장 이후는 외관적으로 상품가치가 없는 것으로 판단되었다. 약품처리에 따른 색소는 BHA, sodium polyphosphate, control 순으로 적었다. 옥돔은 BHA 또는 sodium polyphosphate로서 처리하며 $-35^{\circ}C$이하의 온도에 동결저장함으로서 그 상품가치를 비교적 장기간 유지할 수 있다고 본다. 본 연구는 아시아 재단의 연구보조비(1977연)에 의하여 수행되었으머, 본실험을 도와준 본대학 식품공학과 3년 이병태, 김영준, 정오화 제군에게 사의를 표한다.

• 정보저장시스템학회논문집
• /
• 제1권2호
• /
• pp.127-131
• /
• 2005

We report a nanometer scale mark formation using a $PtO_x$ thin film or a TbFeCo rare-earth transition metal film and the mechanism. The multi-layer samples($ZnS-SiO_2/PtOx/ZNS-SiO_2,\;ZnS-SiO_2/TbFeCo/ZnS-SiO_2$) were prepared with a magnetron sputtering method on a polycarbonate or a glass substrate. By laser irradiation of approximately a few nanoseconds, nanometer scale marks were fabricated. During the fabrication process, the thin films were thermally reacted or inter-diffused during the laser irradiation. 75 nm bubble marks in the PtOx multi-layer sample by an approximately 4-ns laser irradiation. Inside the bubble mark, Pt particles with a few nanometer sizes are distributed. The $50{\sim}100$ nm bubble marks in the TbFeCo multi-layer sample by a few nanosecond laser irradiations. We will report the detail structure of the samples, the bubble mark formation process and the mechanism.

• 전기화학회지
• /
• 제10권2호
• /
• pp.88-93
• /
• 2007

Nano-sized Sn particles were coated with Ni-P layer using an electroless deposition method and their anodic performance was tested for lithium secondary batteries. Uniform coating layers were obtained, of which the thickness was controlled by varying the $Ni^{2+}$ concentration in the plating bath. It was found that the Ni-P layer plays two important roles in improving the anodic performance of Sn powder electrode. First, it prevents the inter-particle aggregation between Sn particles during the charge/discharge process. Second, it provides an electrical conduction pathway to the Sn particles, which allows an electrode fabrication without an addition of conductive carbon. A pseudo-optimized sample showed a good cyclability and high capacity ($>400mAh\;g^{-1}$) even without conductive carbon loading.

• 대한산업공학회지
• /
• 제26권4호
• /
• pp.384-391
• /
• 2000

Most of the previous works on classical location models are based on the assumption that the value(or utilities) of inventory remains constants over time. In this study a special case of location problem is studied for both ameliorating and deteriorating items in two-echelon supply-chain management such as agricultural and fishery products. The objective of this study is to determine the minimum number of storage facilities among a discrete set of location sites so that the probability for each customer to be covered is not less than a critical value. We have formulated this problem using stochastic set-covering problem which can be solved by 0-1 programming method. Also we developed a computer program and applied to a set of problems for fish culture storage and distribution centers and the sample results well show the impact of ameliorating and deteriorating rate on the location problem. For the further study, a graphical user-interface with visualization for input and output is needed to be developed.

• 동아시아식생활학회지
• /
• 제26권4호
• /
• pp.359-369
• /
• 2016

In this study Ragwort, which had various and excellent pharmacological activity, was selected as a functional material, and intended to present an optimum condition of Ragwort Injeolmi by the blanching method, commonly used in the field. The general components, antioxidation, and dietary fiber of Ragwort were analyzed, and produceableness of Ragwort added Injeolmi was reviewed through instrumental inspection and sensory evaluation of various adding ratio of lyophilized Ragwort power and Ragwort pre-processed by blanching. It was proved that the SOD-likely active of Ragwort was 45.69%, total poly- phenol content was 12.45 mg, and total flavonoid content was 10.25 mg. The pH of Injeolmi adding Ragwort powder showed an increasing trend in the order of 0%, 1%, 3%, 5%, while that of Injeolmi adding blanching Ragwort showed increasing trend in the order of 0%, 10%, 15%, 20%, and there were significant difference (p<0.001). The soluble solid content of all sample groups showed constant value, and it was understood that no sugar was added in the process. From chromatography measurement result, a-value (redness) of 1% sample group was the lowest, and there were significant differences among sample groups (p<0.001). During 3 days of storage period, total microbial count of Injeolmi showed increasing trend while the storage period was getting longer. From the acceptability test Injeolmi adding blanching Ragwort had shown generally higher value.

• 한국지하수토양환경학회:학술대회논문집
• /
• 한국지하수토양환경학회 2003년도 추계학술발표회
• /
• pp.199-201
• /
• 2003

The monitoring effectiveness not only depends on the effectiveness of the network, but also the costs of the network. Generally the costs of the monitoring network are mainly on the equipment and personnel; the implementation and maintenance; the observation and sample connection; the sample analysis; and the data storage and processing. The cost of the monitoring network can be expressed as a function of monitoring frequency because the monitoring method can be an automatic or a manual measurement. To determine the sampling frequency of subsidiary groundwater monitoring stations, time series data of national groundwater monitoring stations were used. The proposed optimal sampling frequency for subsidiary groundwater monitoring station is about 7 to 20 days and the average frequency is about 2 weeks.

• 한국식품저장유통학회지
• /
• 제11권3호
• /
• pp.304-312
• /
• 2004

감귤의 수확 후 저장, 유통과정에서 부패 억제 및 품질유지 효과를 얻기 위하여 환경친화적 방법으로서 중-고온 예조처리의 적용 가능성을 확인하고자, 조생종 온주 감귤의 열풍처리에 따른 저장 중 품질특성 변화를 살펴보았다. 45$^{\circ}C$에서 2, 4, 6시간 동안 열풍을 가한 다음, 충분히 냉각시킨 감귤을 통기성 천공 LDPE 필름에 포장하여 5$^{\circ}C$에서 3주, 18$^{\circ}C$에서 1주간저장하면서 호흡률, 과실내부 기체조성,pH, 산도, 가용성 고형분 함량, 과피 표면색, 생체 중량 감소율, 경도, 부패과 발생률, 관능특성 등을 평가하였다. 열풍처리 직후 초기 호홉률은 처리구 모두 무처리구와 비교하여 높았으나 처리시간과는 유의적 상관성이 없었고, 저장 중처구 감귤의 호흡률은 감소하여 21일째는 무처리구와 유사한 수준을 나타내었다. 과실내부 기체조성은 처리구간에 유의적인 차이를 보이지 않았으며, 과즙의 pH, 산도, 가용성 고형분 함량 및 과실의 생체 중량감소와 경도, 과피 표면색 역시 열처리에 의해 거의 영향을 받지 않았다. 한편 부패과 발생률에 있어서는 4시간 이상의 처리구가 꼭지 썩음 현상과 곰팡이 발생정도, 검은 썩음병인 표피 흑변 정도에서 저장 중 낮은 수준을 나타내었다. 그러나 외관품질 및 체감품질에 대한 관능평가에서는 열풍처리구와 무처리구 사이에서의 유의적인 차이를 발견할 수 없었다. 결론적으로 45$^{\circ}C$, 4-6시간의 제한적 열풍처리는 조생 온주 감글의 저장 중 부패과 발생률을 현저히 감소시킴으로서 수확 후 품질유지에 효과적인 중-고온 예조처리 조건임을 확인할 수 있었다.