• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.10
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• pp.93-103
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• 2016

This study consisted of descriptive research to determine the prevalence of dry eye disease using the Ocular Surface Disease Index (OSDI) questionnaire targeting workers in hospitals to understand the differences between general and health related characteristics depending on whether people have dry eye disease, and to determine the influencing factors of the disease. The subjects were 502 (Male: 51, Female: 451) general hospital employees in G-city. The data were collected from October 1 to October 31, 2015. Logistic regression was used to analyze the data. The results showed that hospital workers' prevalence of dry eye disease was 76.1%. Factors influencing DED in this population included currently having or adjusting medication (OR: 4.73), among those who felt their eyes dry, those who visited clinics and received medical treatment (artificial tears) (OR: 2.37), those who felt eye dryness (OR: 2.23), and not eating regularly (OR: 0.55). Moreover, 54.0% of those who had dry eye disease reported serious conditions. Accordingly, education to manage the risk factors of the disease and improve lifestyle is needed to prevent and manage dry eye disease.

• Journal of the Korean Electrochemical Society
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• v.27 no.1
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• pp.40-46
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• 2024

Among the electrode manufacturing processes for lithium-ion batteries, the drying process is crucial for production speed and process cost. Particularly, as the loading level of the electrode increases to enhance the energy density of the battery, optimizing process conditions for electrode drying becomes more critical. In this study, we compared the drying time and electrochemical performance of the positive electrode prepared at different drying temperatures. LiNi_0.6Co_0.2Mn_0.2O₂ (NCM622) was used as the active material and manufactured under various drying temperature conditions ranging from 120 ℃ to 210 ℃ at loading levels of 2.5 and 4.5 mAh cm^-2. The physical and electrochemical properties of the electrodes were compared. As the loading level of the electrode increases, the drying time of the electrode also increases, but this time can be reduced by increasing the drying temperature. The drying temperature used in manufacturing the NCM622 positive electrode does not significantly affect the electrochemical performance but drying above 210 ℃ resulted in an increase in the volume resistivity of the electrode and a decrease in electrochemical performance. Accordingly, in the manufacture of high-loading electrodes, the drying temperature was increased to 190 ℃ to shorten the electrode manufacturing time without a loss of performance.

• Clean Technology
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• v.17 no.3
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• pp.209-214
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• 2011

The effects of inlet gas velocity (0.26-0.31 m/s), inlet gas temperature (315-353 K) and the mass ratio (0.1-0.4) of fine polymer (crosslinked poly methyl methacrylate beads) to inert medium particles on the drying rate of fine polymer in a 0.15 m-ID ${\times}$ 1.0 m-high inert medium fluidized bed dryer have been investigated. Crosslinked PMMA beads of 20 ${\mu}m$ (group C) were used as fine polymer, and glass beads of 590 ${\mu}m$ (group B) were used as the inert medium. The drying rate increases with increasing inlet gas temperature and velocity. However, the drying rate decreases slightly as the mass ratio of fine polymer to inert medium particles increases. The particle size distribution of dried fine polymers was mono distribution.

• Korean Chemical Engineering Research
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• v.60 no.2
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• pp.237-242
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• 2022

In this study, a drying method that can effectively remove residual solvent from (+)-dihydromyricetin was developed. Residual acetone concentration was efficiently removed below ICH-specified value (5,000 ppm) by simple rotary evaporation with ethanol pretreatment. In addition, the residual ethanol met the ICH-specified value (5,000 ppm) by simple rotary evaporation through the addition of water, and the residual moisture also met the specified value (<4%) for active pharmaceutical ingredients. At all the drying temperature (35, 45, and 55 ℃), a large amount of the residual solvent was initially removed during the drying, and the drying efficiency increased when increasing the drying temperature. Removal of residual solvent by ethanol pretreatment was shown to be related to high vapor pressure of acetone-ethanol mixture and hydrogen bonding between acetone and ethanol.

• Journal of the Korea Organic Resources Recycling Association
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• v.31 no.4
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• pp.5-11
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• 2023

This study was conducted to improve energy efficiency and problems such as clumping and fouling in the glue zone that occur in the moisture content range of 40 to 60% when sewage dehydration residue is directly fed into the dryer. The temperature of the hot air is low at 270~300℃, and the paddle-type flotation method and dehydrated residue are applied to the circulated heat storage media to increase the contact area with the hot air, thereby reducing energy recovery and gas emissions. The water content of the dried residue is 2.7. ~7 .5%, the heat of evaporation of moisture was 608.0~690.6 kcal/kg·H₂O, which confirmed an energy saving effect of about 8.8% compared to the heat of evaporation of moisture of 714.5 kcal/kg·H₂O when no heat storage media was used.

• Journal of the Korean Wood Science and Technology
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• v.2 no.2
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• pp.22-24
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• 1974

1. Object and importance of the research. The exports of plywood are increasing annually and it has ranked first in the world market because of the high quality product developed and manufactured using modern techniques. However, it is known that the exports of the other wood products, except plywood, is inactive because of their low quality. Accordingly, to increase the exports of various wood products investigations were carried out on kiln drying techniques to improve the quality of the wood. 2. The details and scope of the research Wet wood should be kiln dried before use to prevent various drying defects such as distortion, shrinkage etc, which would develop after processing, and also wet wood is not suitable for cutting, gluing and finishing. Therefore, the kiln drying properties of lumber from such species as Persimmon, Oak, Ramin and Meranti which are used in large quantity for manufacturing exporting wood products have been studied. Also the real state of kiln drying industry in Korea was investigated. 3. Results and proposal for practical use of the research 3. 1 Results of the research 3.1.1 The end checks and the time for drying from intial moisture content of about 40 percent to 5 percent moisture content in ovendry were investigated as Table 1. 3.1.2 The kiln dried results, for 30mm stock, which are presented by using kiln schedule Table 2 are as Table 3. 3.1.3 The kiln schedule for Persimmon which has a normal drying properties is given in Table 4. However, the persimmon which has easy checking properties should be air dried under a relative humidity of above 85% until reaching about 25 percent moisture content. 3.1.4 The kiln schedules for ramin, meranti and oak are given respectively as follows. Ramin kiln schedule ............ Table 5 and Table 6 Meranti kiln schedule ............ Table 7 Oak kiln schedule ............ Table 8 3.2 Proposal for practical use of the research Firms using the above species should be informed the results of the research so they can be used to preventing drying defects and shortening drying time.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2011.10a
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• pp.18-18
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• 2011

본 연구는 태양초 품질에 미치는 후숙방법과 산광재료의 효과를 구명하기 위하여 2011년 8월부터 2011년 9월 25일까지 충청북도농업기술원 1중 플라스틱 하우스에서 수행하였다. 전처리 방법은 고추 수확 후 벌크(대조구), 하우스 밀봉, 비닐밀봉 등 3처리를 하였으며, 산광재료는 관행(무차광, 대조구), 차광망(35%), 천막지, 백색부직포, 흑색부직포를 건조대 위의 멀칭용 철사에 고정하여 실험을 수행하였다. 고추건조대($6{\times}1.5{\times}0.75(m)$, $L{\times}W{\times}H$)를 각 앵글로 설치하고, 고추 건조기의 건조 깔판을 깔고 고추를 널어 건조하였다. 플라스틱하우스 바닥에는 천막지를 깔고 토양으로부터 습기를 차단하여 고추 건조를 촉진코자 하였다. 고추 전처리 방법은 벌크 건조가 건조기간이 짧고 비상품과율이 낮아 건조 효율이 우수하였으나, 태양초 생산을 위한 전처리 방법으로는 하우스 밀봉이 우수하였다. 산광재료는 백색부직포 처리시 고추의 수분 증발 속도가 대조구보다 뒤졌으나, 다른 처리보다 온도가 높아 건조기간을 단축할 수 있었고, 색택이 우수할 뿐만아니라 상품성도 우수하였다.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2002.07a
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• pp.157-162
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• 2002

지금까지 우리나라 벼농사는 고품질 쌀의 생산보다는 다수확재배기술로 생산량을 늘리는 것이 농가소득에 유리하였다. 그러나 소비수준이 높아지고 쌀의 제고가 충분한 현시점에서는 풀질의 경쟁력 향상이 더욱 중요하다 이를 위해서는 고품질 쌀 생산을 위한 건조, 저장, 가공 등 기반시설의 현대화하여 브랜드화에 의한 차별화를 통하여 소비자의 신뢰를 얻기 위한 연구가 수행되어야 할 것이다. 쌀의 밥맛을 결정하는 요인은 품종, 재배, 관리, 수확에 이르기까지 관계가 있겠지만, 수확후처리 공정과정에서도 품질의 우열이 좌우된다 특히 건조 중 열풍온도 관리 소홀로 인하여 과건이 되는 경우에는 밥맛에 치명적이라고 할 수 있다. (중략)

• Journal of the Korean Society of Food Science and Nutrition
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• v.19 no.6
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• pp.555-564
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• 1990

The headspace gas chromatographic(analytical) technique was used to evaluate the retention of volatiles in fruit juices during freeze drying as a function of freezing rate, the content of initial solid and chamber pressure. The effects of freezing rate and drying time on the volatile retention under the experimental conditions were marked, particulary at long freezing time. The retention of volatiles in the freeze dried was largely affected by the freezing rate. The highest volatile loss under the freeze drying conditions was observed during the first stage of drying. The behavior during freeze drying of the volatile substances was affected by high content of initial solid. The volatile retention was higher in quick freeze drying than slow freeze drying and low pressure than high.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2002.02a
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• pp.349-354
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• 2002

쌀 소비량은 생활 수준 향상과 외식 및 식품 산업의 발달로 감소하고, 고품질 쌀을 요구하는 성향이 높아지고 있다. 현재, 고품질 쌀을 생산할 수 있는 기술과 제반 요건은 구비되어 있으나, 수확 후 건조·저장 중에 쌀의 품질이 저하된다. 특히 건조 중 품질 저하는 고온건조에 의한 동할 발생 및 과건조가 주요 원인이다. 이를 해결하기 위해 원적외선 건조 시스템에 관한 연구가 진행 중이다. 본 연구에서는 방사율이 높고, 접착성 및 내열성 등이 강한 곡물 건조기용 방사체 코팅원료를 개발하고, 이 원료를 원적외선 방사체에 코팅한 후 방사체의 형태와 크기에 따라 표면 온도 분포 및 연료 소비량 등을 측정 분석하여 방사체의 특성과 적정 조건을 규명하고자 하였다. 연구 결과를 요약하면 다음과 같다. (1) 세라믹 코팅 원료의 배합비는 세라믹분말 40%와 결합재 60%가 접착력과 가열경화 후 표면이 양호한 것으로 나타났다. (2) 노즐의 유량 및 분무각에 따른 버너의 화염길이 및 폭은 노즐유량이 증가함에 따라 증가하는 경향을 나타내었다. (3) 방사체 위치별 표면온도편차는 방사체 길이가 1350mm인 것이 작은 것으로 나타났고, 열풍유동관 직경이 Rounding type의 경우 76.3mm, Right angle type의 경우 89.1mm일 때 표면 온도편차가 적었다. (4) 연료소비량은 열 풍유동관 직경이 클수록, 방사체 길이가 길수록 증가하는 경향을 나타내었고, Right angle type이 Rounding type에 비하여 연료소비량이 약간 높은 것으로 나타났다.