• Journal of Nutrition and Health
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• 제24권1호
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• pp.12-19
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• 1991

장기간의 연속적 오존조사와 식이항산화제 및 식이지방의 불포화도가 생쥐의 폐와 간조직의 지질산화에 미치는 영향을 조사하였다. 실험동물들은 각각 0.25ppm, 0.50ppm의 오존 또는 정상적 대기환경에서 18개월간 식이항산화제의 수준과 식이지방의 불포화도를 달리한 실험식이들에 의해 사육되었으며 조직의 지질과산화의 정도는 Thiobarbituric acid 반응물질의 농도와 free malonaldehyde의 농도에 의해 측정되었다. 본 연구의 결과, 장기간의 오존조사는 실험식이의 종류에 관계없이 폐조직과 간조직의 지질과산화를 유도하지 않음이 발견되었으며 식이중 비타민 E의 함량과 조직 의 지질과산화생성물의 농도와는 역의 관계를 나타냈고 적절한 식이비타민 E 의 첨가(30ppm)는 식이지방의 불포화도에 관계없이 조직의 지질과산화를 억제하는데 효과적임에 관찰되었다.

• Elastomers and Composites
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• 제54권2호
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• pp.110-117
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• 2019

The characterization of the ozone oxidation for raw natural rubber (NR) was investigated under controlled conditions through image and fourier transform infrared (FT-IR) analysis. The ozone oxidation was performed on a transparent thin film of raw NR coated on a KBr window in a dark chamber at $40^{\circ}C$ under low humidity conditions to completely exclude thermal, moisture, or light oxidation. The ozone concentration was set at 40 parts per hundred million (pphm). Before or after exposure to ozone, the image of the thin film for raw NR was observed at a right or tilted angle. FT-IR absorption spectra were measured in the transmission mode according to ozone exposure time. The ozone oxidation of NR was determined by the changes in the absorption peaks at 1736, 1715, 1697, and $833cm^{-1}$, which were assigned to an aldehyde group (-CHO), a ketone group (-COR), an inter-hydrogen bond between carbonyl group (-C=O) from an aldehyde or a ketone and an amide group (-CONH-) of protein, and a cis-methine group ($is-CCH_3=CH-$, respectively. During ozone exposure period, the results indicated that the formation of the carbonyl group of aldehyde or ketone was directly related to the decrement of the double bond of cis-1,4-polyisoprene. Only carbonyl compounds such as aldehydes or ketones seemed to be formed through chain scission by ozone. Long thin cracks with one orientation at regular intervals, which resulted in consecutive chain scission, were observed by image analysis. Therefore, one possible two-step mechanism for the formation of aldehyde and ketone was suggested.

• 한국산업보건학회지
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• 제28권2호
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• pp.200-210
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• 2018

Objectives: The purpose of this study is to assess the exposure to ozone and total volatile organic compounds(TVOCs) generated during welding work at a shipyard and recommend respiratory protective equipment(RPE) adequate against these hazards. Method: Ozone was collected for about 30 minutes at two-minutes intervals using a direct reading instrument, specifically an ozone analyzer(Serinus 10, Ecotech, Australia). TVOCs were collected for about 30 minutes at three-minute intervals using a portable GC (Alpha 115, Synspec BV, the Netherlands), and were determined simultaneously by area sampling at the welding plume closest to the welder's breathing zone. The total measurements were 162 for ozone($CO_2$ welding 47, TIG 60, stick 55), and 136 for TVOCs($CO_2$ 65, TIG 50, stick 21). Based on these measurements, a literature survey was conducted to assess the adequacy of RPE. Results: Relative to Korean OEL, measurements above STEL 0.2 ppm were 23.4% for $CO_2$, 63.3% for TIG and 14.5% for stick welding. There were significant differences(p=<0.0001) among welding types. Compared with ACGIH peak exposure of 0.4 ppm for ozone, which is not applied in Korea, $CO_2$ welding exceeded it by 10.6%, TIG by 40.0% and stick by 7.3%. Although it was not feasible to compare them directly since there are no Korean OEL, TVOCs had very high levels similar to the concentrations before moving into a new apartment and about 10-20 times the indoor air quality recommendations for some individual measurements. Conclusions: As ozone removal RPE has been recommended in welding environments for a long time(Lunau, 1967), this fact was demonstrated based on the results of the on-site work environment measurements(ozone and TVOCs). In conclusion, for all welding at a shipyard, gas/vapor and particulate combination RPE are recommended. If this is not possible, it should at least be present for TIG welding.

• 한국작물학회지
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• 제46권2호
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• pp.78-83
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• 2001

Two rice cultivars of the japonica type, ozone-resistant Ilpumbyeo (IL) and ozone-susceptible Keu-mobyeo#l (KM) were exposed to ozone ($O_3$) at 0.15 ppm for 30 days. The available nutrient regimes were varied by doubling the supply of nitrogen (N), phosphorus (P) and potassium (K) within a basic fertilizer status (N, P, K; 15, 12, 12 kg l0$a^{-1}$). There was little difference on plant height between ozone-treated and nontreated plants. The most significant ozone stress on tiller number was shown on the 30th day of ozone exposure. Slight recovery from ozone stress was noted on the 60th day. On the 30th day, tiller number was greatly decreased by 40.8% in IL and 64.6% in KM, whereas at a high nitrogen supply regime (2N), it was decreased by 21.4% in IL and 42.7% in KM as compared to the control not treated with ozone at basic fertilizer status. The inhibition of tiller production caused by ozone exposure was alleviated on the 60th day. In both cultivars, number of spikelets per plant and weight of 100 grains were affected little by the ozone treatment irrespective of nutrient regime. However, the number of panicles per plant and yield were reduced significantly. In both cultivars, yield of ozone-treated plants with 2N status was 12.4-16.1 % higher than that of the ozone-treated plants with basic nutrient status. A significant yield decrease of 47.8% and 33.4% was observed for IL and KM, respectively, in ozone-treated plants with higher potassium (2K) status.

• 한국농림기상학회지
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• 제4권1호
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• pp.29-37
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• 2002

본 연구는 자작나무류의 오존에 대한 잎의 가시적 피해율과 생장 반응을 측정하여 수종별 오존 민감성을 비교하고자 하였다. 시험 재료는 거제수나무, 물박달나무, 자작나무, 사스래나무로 온실에서 양묘하여 포트로 옮겨 심고, 100 ppb의 오존 농도에서 하루 8시간 씩 5주 동안 오존에 노출시킨 후 그들의 가시적 피해율과 잎 수, 잎 면적 및 생장(수고와 직경 상대생장율, 잎, 줄기, 뿌리의 건중량)을 측정하여 수종간, 처리간 차이를 비교하였으며 연구 결과는 다음과 같았다. 4개 수종의 오존에 대한 반응은 매우 다르게 나타나는데 사스래나무를 제외한 3개 수종의 생장은 오존에 의해 크게 영향을 받아 감소하는 것으로 보인다. 특히 초기에 많은 조기낙엽을 나타내는 거제수나무와 가시적 피해율이 가장 높은 물박달나무는 오존에 대해 민감한 수종으로 판단된다. 그러나 사스래나무는 초기에 오존에 대한 영향으로 생장이 감소하지만 오존에 대한 적응을 통하여 생장을 회복하는 내성 수종으로 판단된다.

• 한국환경농학회지
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• 제6권1호
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• pp.38-43
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• 1987

수도(水稻)의 영양상태(營養狀態)와 Ozone가스 피해(被害)와의 관계(關係)를 구명(究明)하기 위(爲)하여 진주(眞珠)벼를 공시(供試)하여 질소(窒素), 린산(燐酸), 가리(加里), 표준비(標準肥)에 각각(各各) 50%증비(增肥) 및 50%감비(減肥)하여 Ozone가스 0.3ppm을 3시간접촉후(時間接觸後)에 엽피해율(葉被害率), malondialdehyde, peroxidase의 전기영동(電氣泳動) 및 무기성분함량변화(無機成分含量變化)을 조사(調査)한 결과(結果)는 다음과 같다. 1. 질소증시(窒素增施) 및 가리감비(加里減肥)로 Ozone가스의 피해(被害)가 증가(增加)된다. 2. Ozone가스 피해율(被害率)에서 malondialdehyde의 함량(含量)이 증가(增加)된다. 3. $K_2O/N$비(比)가 낮을수록 엽피해(葉被害)가 증가(增加)한다. 4. Ozone가스 피해(被害)로 엽중(葉中) 질소(窒素), 린산(燐酸), 가리함량(加里含量)이 감소(減少)하는 경향(傾向)이다. 5. Peroxidase를 전기영동(電氣泳動)한 결과(結果) 시비량(施肥量)에 따른 band의 차이(差異)는 발견(發見)하지 못하였으나 Ozone가스 접촉(接觸)으로 2, 3, 4번째 band에서 변화(變化)가 있었다.

• 한국환경과학회지
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• 제25권2호
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• pp.191-216
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• 2016

Since prolonged exposure to elevated ozone ($O_3$) concentrations is known to be harmful to human health, appropriate control strategies for ozone are needed for the non-attainment area such as Seoul, Korea. The goal of this research is to assess factors linked with the 1-hour ozone exceedance through a decision tree model. Since ozone is a secondary pollutant, lag times between ozone and explanatory variables for ozone formation are taken into account in the model to improve the accuracy of the simulation. Results show that while ozone concentrations of the previous day and $NO_2$ concentrations in the morning are major drivers for ozone exceedances in the early afternoon, meteorology plays more important role for ozone exceedances in the late afternoon. Results also show that a selection of lag times between ozone and explanatory variables affect the accuracy of predicting 1-hour ozone exceedances. The result analyzed in this study can be used for developing control strategies of ozone in Seoul, Korea.

• 한국농림기상학회지
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• 제11권1호
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• pp.3-12
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• 2009

수목의 오존 내성을 단기 노출 후 나타난 생리적 피해와 생화학적 반응들의 표준화 지수로 결정하였다. 모감주나무, 벽오동, 때죽나무, 물푸레나무, 백당나무를 150ppb 오존 노출 시킨 후, 광합성 특성, MDA 함량 및 항산화효소의 활성을 측정하여 피해지수는 광합성 파라미터와 MDA 함량 변화를 이용하여 계산하였으며, 내성지수는 항산화효소의 활성 변화를 측정하여 산출하였다. 순양자수율, 탄소고정효율, 광호흡속도는 오존 노출시간에 따라 감소하여, 스트레스 평가지표로 적당한 것으로 판단되었다. 항산화효소의 활성은 수종, 노출시간 및 효소 종류에 따라 다양한 결과를 보여 주었다. 모감주나무 SOD 활성은 오존 노출시간에 따라 증가하였고, 물푸레나무의 SOD 활성은 오존 노출 6 시간 후에 증가하였으며, 벽오동의 CAT 활성은 무처리보다 낮았다. 표준화 지수를 기초로 한 5개 수목의 오존 내성은 두 내성 수종(물푸레나무>모감주나무)과 세 민감성 수종(때죽나무>벽오동>백당나무)으로 구분되었다.

• The Journal of Advanced Prosthodontics
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• 제8권4호
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• pp.290-295
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• 2016

PURPOSE. The aim of this study was to evaluate the effect of paracetic acid (PAA) and ozone disinfection on the tensile bond strength (TBS) of silicone-based resilient liners to acrylic resins. MATERIALS AND METHODS. One hundred and twenty dumbbell shaped heat-polymerized acrylic resins were prepared. From the mid segment of the specimens, 3 mm of acrylic were grinded off and separated parts were reattached by resilient liners. The specimens were divided into 2 control (control1, control7) and 4 test groups of PAA and ozone disinfection (PAA1, PAA7, ozone1 and ozone7; n=10). While control groups were immersed in distilled water for 10 min (control1) and 7 days (control7), test groups were subjected to PAA (16 g/L) or ozone rich water (4 mg/L) for 1 cycle (10 min for PAA and 60 min for ozone) per day for 7 days prior to tensile tests. Measurements of the TBS were analyzed using 3-way ANOVA and Tukey's HSD test. RESULTS. Adhesive strength of Mollosil decreased significantly by application of ozone disinfection. PAA disinfection had no negative effect on the TBS values of Mollosil and Molloplast B to acrylic resin. Single application of ozone disinfection did not have any negative effect on TBS values of Molloplast B, but prolonged exposure to ozone decreased its adhesive strength. CONCLUSION. The adhesion of resilient liners to acrylic was not adversely affected by PAA disinfection. Immersion in ozonated water significantly decreased TBS of Mollosil. Prolonged exposure to ozone negatively affects adhesion of Molloplast B to denture base materials.

• 한국식품저장유통학회지
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• 제5권1호
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• pp.73-80
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• 1998

Shelf-life of soybean curd prepared with ozone-treated soybeans investigated on pH, acidity, sour taste, slime formation during storage at 3$0^{\circ}C$. Total Plate counts of raw soybeans showed about log 7.0 CFU/g before ozone treatment. The sterilization efficiency of raw soybeans showed the most effective in 0.5ppm of aqueous ozone treatment at 4$^{\circ}C$ for 90 minutes. Raw soybeans were treated with ozone by different methods; (1) Ozone treatment for 90 + 90 minutes (first 3.5~5 hours and later 8.5~10 hours) of 10 hours during soaking in aqueous solutions at 4$^{\circ}C$ (OW). (2) Ozone treatment by exposure first to 30ppm of gaseous ozone for 90 minutes and then allied to OW method (GO+OW). The log reduction of raw soybeans treated by OW and GO+OW methods showed 3.72 and 4.15, respectively. Soybean curd prepared with OW and GO+OW-treated soybeans kept the shelf-life of 4 and 5.5 days at 3$0^{\circ}C$, respectively, but, that without ozone treatment spoiled at me day.