고성능 복합재료는 기존의 소재에 비해 우수한 기계적 물성을 보이며 특히 높은 비강도를 보인다. 복합재료 의 매트릭스로 사용되는 에폭시 수지는 이들의 독특한 화학반응성, 경화반응에 사용되는 경화제의 적절한 조합으로 많은 다양한 특성을 보일 수 있다. 본고에서는 고성능 복합재 구조물 제작에 사용되어온 에폭시 수지 시스템을 소개 하고자 한다. 필라멘트 와인딩 공법에 사용되는 에폭시 수지와 프리프레그 제조에 사용되는 에폭시 수지의 조성과 특 성을 중심으로 설명하였다.

King oyster mushroom (Pleurotus eryngii), an improved species of oyster mushroom, is a popular ingredient in Asian cuisine. Spleen cells were treated with various concentrations (0, 5, 10, 50, 100, 250, 500, and 1,000 μg/mL) of king oyster water extracts (KOWE); then, the proliferation of the cells was measured 24, 48, and 72 h after each treatment. Also, type 1 T helper cytokine productions (TNF-α, IFN-γ, and IL-2) were measured in activated macrophage by KOWE in seven concentrations. Under the condition of its 50, 100, 250, and 1,000 μg/mL for 48 h, the proliferation of cells was increased. However, there was no significant fluctuation in the spleen cells proliferation for 24 and 72 h-long KOWE exposure. To determine cytokine (TNF-α, IFN-γ, IL-2) productions of type 1 T helper cells, macrophage was stimulated by KOWE for 48 h. Treatment of KOWE gave a rise to the levels of TNF-α and IFN-γ, but not in that of IL-2 productions. These results suggest that king oyster mushroom water extracts may be beneficial for enhancing immune functions in its high concentration.

Plantago asiatica L., observed frequently in East Asia, is a known herb used in traditional medical remedies several studies report that P. asiatica L has anti-inflammatory and antioxidant effects. To determine the production of cytokines (IL-2, IFN-γ, and TNF-α) induced by lipopolysaccharide (LPS) and non-LPS-stimulated macrophages, an ELISA assay was conducted using cytokine kits. Mice splenocytes were cultured for 48 h with various concentrations of P. asiatica L. (5, 10, 50, 100, 250, 500, and 1,000 μg/mL) or with mitogens (ConA or LPS). P. asiatica L. increased the proliferation of mice splenocytes, especially under the condition of its concentration ranging from 250 to 1,000 μg/mL. In addition, Plantago asiatica L. notably induced cytokine production of (IL-2, IFN-γ, and TNF-α) at its concentration of 250~500 μg/mL. These results suggest that supplementation with P. asiatica L. water extracts may play a potential role in enhancing immune function by mediating splenocyte proliferation and cytokine production through its anti-inflammatory activit.

The purpose of this study was to identify the consumers’ demands on functional design of sports climbing pants. Data were collected through a field survey. 82 male and 70 female amateur sports climbers in Seoul participated. The questionnaires measured aspects of functional design in sports climbing pants, specifically motion adaptability, comfort and aesthetic value of the climbing pants. The results of this study show that comfort during climbing postures was the most important value of the climbing pants. The subjects sought motion adaptability at the hip, crotch, thigh and knee. The preferred style and degree of fit of climbing pants were differed according to gender. Men preferred loose or semi tight fit style climbing pants but women preferred the leggings style of the sport pants. The soft touch seam line and body shaping function were also important for women. The type of pants preferred for sports climbing also differed by the climbing experience period. Men began to wear the outdoor mountaineering style pants when they had experienced sports climbing for 6 months and to wear the climbing expert style pants when they had experienced sports climbing for a year. Most women wore leggings style sports pants from the beginner stage. This study also analyzed Korean market trend in 2016~2017 F/W for sports climbing pants design. The men’s pants were more likely to be designed to improve mobility compared to the women’s pants, even though the aesthetic value of the sports climbing pants was important for women.

The sewage and wastewater (SAW) are a well-known major source of eutrophication and greentide in freshwaters and also a potential source of thermal pollution; however, there were few approaches to thermal effluent of SAW in Korea. This study was performed to understand the behavioral dynamics of the thermal effluents and their effects on the water quality of the connected streams during winter season, considering domestic sewage, industrial wastewater and hot spring wastewater from December 2015 to February 2016. Sampling stations were selected the upstream, the outlet of SAW, and the downstream in each connected stream, and the water temperature change was monitored toward the downstream from the discharging point of SAW. The temperature effect and its range of SAW on the stream were dependent not only on the effluent temperature and quantity but also on the local air temperature, water temperature and stream discharge. The SAW effects on the stream water temperature were observed with temperature increase by 2.1~5.8℃ in the range of 1.0 to 5.5 km downstream. Temperature effect was the greatest in the hot spring wastewater despite of small amount of effluent. The SAW was not only related to temperature but also to the increase of organic matter and nutrients in the connected stream. The industrial wastewater effluent was discharged with high concentration of nitrogen, while the hot spring wastewater was high in both phosphorus and nitrogen. The difference between these cases was due to with and without chemical T-P treatment in the industrial and the hot spring wastewater, respectively. The chlorophyll-a content of the attached algae was high at the outlet of SAW and the downstream reach, mostly in eutrophic level. These ecological results were presumably due to the high water temperature and phosphorus concentration in the stream brought by the thermal effluents of SAW. These results suggest that high temperature of the SAW needs to be emphasized when evaluating its effects on the stream water quality (water temperature, fertility) through a systematized spatial and temporal investigation.

This study aimed to identify milling characteristics depending on the number of a cutting roller’s air vent and blowing velocity to remove rice bran by the cutting type milling machine which can minimize the conventional milling process. The level of whiteness was found to be 38±0.5 in all the conditions, showing consistent whiteness levels during milling. The rice temperatures turned out to be 15.4 and 14.6oC which were rather low-level under the conditions of the cutting roller with 3 vents and blowing velocities of 35 and 40 m/s respectively. Cracked rice ratio was 2.13% under the conditions of the cutting roller with 3 vents and a blowing velocity of 35 m/s. Broken rice ratio showed the range of 0.762-0.869%, reflecting a low level. Turbidity after milling was decreased, as blowing velocity became faster. Energy consumption for milled rice production was decreased, as blowing velocity became faster. The optimum milling condition for cutting type milling machine depending on air vent number of cutting roller and blowing velocity was found to be 3 vents and 35 m/s.

This study aimed to identify milling characteristics depending on the number of a cutting roller’s air vent and blowing velocity to remove rice bran by the cutting type milling machine which can minimize the conventional milling process. The level of whiteness was found to be 38±0.5 in all the conditions, showing consistent whiteness levels during milling. The rice temperatures turned out to be 15.4 and 14.6oC which were rather low-level under the conditions of the cutting roller with 3 vents and blowing velocities of 35 and 40 m/s respectively. Cracked rice ratio was 2.13% under the conditions of the cutting roller with 3 vents and a blowing velocity of 35 m/s. Broken rice ratio showed the range of 0.762-0.869%, reflecting a low level. Turbidity after milling was decreased, as blowing velocity became faster. Energy consumption for milled rice production was decreased, as blowing velocity became faster. The optimum milling condition for cutting type milling machine depending on air vent number of cutting roller and blowing velocity was found to be 3 vents and 35 m/s.

목적: 조절장애를 제외한 굴절장애 중 원시 질환으로 병원에 내원하는 환자수를 알아보고, 의료비용을 분석하여 원시 환자수 및 의료비용 증가율을 알아보려 하였다. 방법: 건강보험심사평가원에서 제공하는 2014년 1월 1일 ~ 2016년 12월 31일까지의 환자 표본자료를 이용하여 3년간 원시 질환으로 병원을 내원한 외래 및 환자를 대상으로 하였다. 결과: 원시 환자수는 2015년에 7.95% 증가하여 가장 많았으며, 남자보다 여자가 더 많았다. 지역별 원시 환자수는 경기도가 3년 연속 60만명 이상으로 가장 많았으며, 서울특별시가 그 다음으로 환자수가 많았다. 세종특별자치시는 2012년 승격으로 인해 원시 환자수가 가장 적었다. 원시 질환의 진료비는 3년간 증가하고 있으며 2015년의 증가율이 가장 높았다. 3년간 평균 1인당 진료비는 44천원으로 울산이 가장 높았으며 경상북도가 36천원으로 가장 낮았다. 결론: 본 연구를 통해서 원시 환자수와 의료비용의 증가율 분석으로 국내 원시 환자수 현황을 확인하였다. 추후 원시 질환으로 병원에 내원하는 환자의 인구, 사회학적 특성 등을 분석하여 의료 서비스 이용 양상에 관한 후속연구가 필요하다고 사료된다.

목적: 조절장애를 제외한 굴절장애 중 부동시 및 부등상시 질환으로 병원에 내원하는 환자 수를 알아보고, 의료비용을 분석하여 부동시 및 부등상시 환자수 및 의료비용 증가율을 알아보려 하였다. 방법: 건강보험심사평가원에서 제공하는 2014년 1월 1일 ~ 2016년 12월 31일까지의 환자 표본자료를 이용하여 3년간 부동시 및 부등상시 질환으로 병원을 내원한 외래 및 환자를 대상으로 하였다. 결과: 부동시 및 부등상시 환자수는 2015년에 16.08% 증가하여 가장 많았으며 2016년도에는 2015년에 비해 10.93% 환자수가 감소하였다. 부동시 및 부등상시 환자수는 남자보다 여자가 더 많았다. 지역별 부동시 및 부등상시 환자수는 경기도가 3년 연속 가장 많았으며, 서울특별시가 그 다음으로 환자수가 많았다. 부동시 및 부등상시 질환의 진료비는 2015년 에 27.73% 증가하여 가장 높았으며, 2016년도에는 5.63% 감소하였다. 3년간 평균 1인당 진료비는 50천원으로 대전이 가장 높았으며 전라남도가 36천원으로 가장 낮았다. 결론: 부동시 및 부등상시 환자수와 의료비용의 증가율 분석으로 국내 부동시 및 부등상시 환자수 현황을 확인하였다. 추후 부동시 및 부등상시 질환으로 병원에 내원하는 환자의 인구, 사회학적 특성 등을 분석하여 의료 서비스 이용 양상에 관한 후속연구가 필요하다고 사료된다.

목적 : 병원에 내원하는 근시 환자수를 통하여 유병률을 분석하고 의료비용을 통하여 근시 환자의 1인당 진료비의 변화추이를 분석하고자 하였다. 방법 : 건강보험심사평가원에서 제공하는 환자표본자료를 이용하여 근시로 병원에 내원한 외래 및 입원 환자를 대상으로 하였다. 유병률은 2015년도 인구총조사 데이터를 활용하였다. 결과 : 3년간 근시로 병원에 내원한 환자 수는 2015년도에 가장 많았으며, 외래진료가 대부분이었다. 남 성보다 여성의 환자수가 많았으며, 남성은 2016년도에 가장 많았고 여성은 2015년도에 가장 많았다. 의료기 관별 환자 수는 의원급이 가장 많았으며 보건기관 등이 가장 적었다. 지역별 환자 수는 서울과 경기지역이 많았으며 세종시가 가장 적었다. 근시 유병률은 인구 천 명당 남성은 25.15명, 여성은 30.17명으로 나타났 다. 의원급 요양기관의 유병률은 인구 천 명당 25.90명으로 가장 높게 나타났다. 광주지역의 유병률이 인구 천 명당 39.15명으로 가장 높게 나타났다. 근시로 내원하여 진료 받은 3년간 전체 평균 진료비는 서울이 가 장 많았으며, 대부분의 지역에서 2014년부터 2016년까지의 3년 동안 1인당 진료비가 증가하였다. 결론 : 근시로 병원을 내원하는 전체 환자수와 의료비용은 3년 동안 점차 증가하고 있는 추세이다. 이에 본 논문이 근시 환자의 안경원을 포함한 의료 서비스 이용 양상에 관한 기초자료로 도움이 될 것이라 생각한다.

단백질과 사포닌 함량이 높은 해삼 열수 추출물을 첨가한 산성 음료는 응집, 침전 및 해삼 특유의 이취로 인하여 음료 제조에 많은 제한점이 있다. 단백질 클라우드 에멀션 음료 시스템은 고단백질 기능성 음료 제조 및 이취를 차폐할 수 있는 특성이 있고, 증점제로 사용되는 펙틴은 산성 조건에서 단백질과 콤플렉스를 형성함으로써 응집과 침전을 억제할 수 있다. 따라서 본 연구에서는 클라우드 에멀션 시스템에 해삼 열수 추출물 분말을 첨가하여 모델 음료를 제조하였으며 펙틴의 함량을 조절하면서 pH와 열처리 조건에 따른 모델 음료의 이화학적 특성을 관찰하였다. 해삼 열수 추출물 분말은 고온(121oC), 고압(15 psi) 조건에서 추출한 후 분무 건조하여 확보하였으며 단백질, 다당, 회분, 수분함량은 각각 43.46, 44.97, 5.38, 4.19%이었다. 모델 음료는 올리브유(0.1%), 해삼 열수 추출물 분말(2%), 유청 단백질(2%), 펙틴(0.01-2%)을 혼합한 후 고압 균질기(4500 psi)를 이용하여 균질화하였다. 제조한 클라우드 에멀션 모델 음료는 30oC와 85oC에서 각각 2 또는 30 min 동안 열처리를 하였다. 펙틴, 유청 단백질의 ξ-potential과 입자크기는 pH를 7에서 3으로 감소시킴에 따라서 증가하였다. 펙틴을 0.01%에서 2% 범위로 첨가한 모델 음료의 ξ-potential과 입자크기는 펙틴함량의 증가에 따라서 증가하였다. 저농도의 펙틴(0.01-0.1%)을 첨가한 경우에는 응집과 상분리 현상이 발생하지 않았다. 그러나 고농도 펙틴(0.5-2.0%)의 첨가, pH를 7에서 3으로 감소 및 85oC에서 30 min 동안의 열처리 조건에서는 complex coacervation에 의한 응집과 상분리 현상이 발생하였다.

In this paper, the method of vibration analysis for calculating the natural frequency is presented. This method is a simple but exact method of calculating natural frequencies corresponding to the modes of vibration for the cantilevered composite materials conical beam. The influence of natural frequency of the cantilevered composite materials conical beam is presented. This method may be extended to stability analysis of complex structureal elements.

Understanding effects of thermal pollution and acidification has long been a concern of aquatic ecologists, but it remains largely unknown in Korea. This study was performed to elucidate the effects of thermal wastewater effluent (TWE) and acid rain on water quality and attached algae in a small mountain stream, the Buso Stream, a tributary located in the Hantan River basin. A total of five study sites were selected in the upstream area including the inflowing point of hot-spring wastewater (HSW), one upstream site (BSU), and three sites below thermal effluent merged into the stream (1 m, 10 m and 300 m for BSD1, BSD2, and BSD3, respectively). Field surveys and laboratory analyses were carried out every month from December 2015 to September 2016. Water temperature ranged 1.7~28.8°C with a mean of 15.0°C among all sites. Due to the effect of thermal effluent, water temperature at HSW site was sustained at high level during the study period from 17.5°C (January) to 28.8°C (September) with a mean of 24.2±3.7°C, which was significantly higher than other sites. Thermal wastewater effluent also brought in high concentration of nutrients (N, P). The effect of TWE was particularly apparent during dry season and low temperature period (December~March). Temperature effect of TWE did not last toward downstream, while nutrient effect seemed to maintain in longer distance. pH ranged 5.1~8.4 with a mean of 6.9 among all sites during the study period. The pH decrease was attributed to seasonal acid rain and snow fall, and their effects was identified by acidophilic diatoms dominated mainly by Eunotia pectinalis and Tabellaria flocculosa during March and August. These findings indicated that water quality and periphyton assemblages in the upstream region of Buso Stream were affected by thermal pollution, eutrophication, and acidification, and their confounding effects were seasonally variable.

Euiam and Paldang Reservoirs have often been facing water quality problems, such as eutrophication, algal blooms and off-flavors by treated wastewater effluent (TWE) in the North-Han and the Han River basins, but little is examined on the direct biological effect of TWE. This study tested algal growth potential (AGP) of four TWEs discharged into Euiam and Paldang Reservoirs to evaluate water fertility in September 2014 and March and September 2015. Test alga was used Anabaena circinalis isolated from Paldang Reservoir. Mean concentration of T-N and T-P in TWEs was 3,956.7 μg N L-1 and 50.8 μg P L-1, and the proportion of NO3-N and PO4-P to the total fraction was 72.1% and 40.8%, respectively. Both N and P were high in TWEs, but much higher N than P concentration indicates strong P-limitation. As a consequence, the maximum AGP was determined by PO4-P concentration (r=0.998, p<0.01). Mean AGP value was 15.4 mg dw L-1 among four effluents indicating its eutrophic condition. Due to the establishment of tertiary (advanced T-P) treatment method in the studied plants recently, P concentration was significantly decreased in TWEs compared to the years prior to 2012. However, P concentration seems to be still high enough to cause eutrophication and algal blooms. Therefore, wastewater treatment to P-free level needs to be considered if effluents are directly discharged into the drinking water resources.

The Youngsan River estuary was physically changed by the construction of a sea embankment at near the mouth of estuary. Weirs were also constructed recently in the freshwater zone and it was reported that algal blooms occur more frequently. The freshwater introduced into saltwater zone from sluice gates of the embankment affects water quality but it has not been addressed that how the freshwater inputs influence the health of marine ecosystem. In this study, we used the data of water properties and phytoplankton communities collected at three stations for 4 days including before the freshwater discharge, during the discharge and after 1 and 2 days of discharge events. WQI (water quality index), TRIX (trophic status index) and P-IBI (phytoplankton index of biotic integrity) were used to evaluate the ecosystem health and long-term data were also utilized to determine the criteria for P-IBI. The results showed that grades of the ecosystem health assessed by the indices were low at the station near the gates and increased as downstream. However, the temporal pattern of grades was different depending on methods. Grades of WQI and TRIX decreased during the discharge and restored after the discharge whereas the grades of P-IBI decreased slightly even after the discharge. This suggests that P-IBI is more applicable to estuarine systems where experience extreme change of water properties than WQI and TRIX since P-IBI includes phytoplankton that can respond quickly to the change.

This study explored spatiotemporal variability of water quality in correspondence with hydrometeorological factors in the four stations of Euiam Reservoir located in the upstream region of the North-Han River from May 2012 to December 2015. Seasonal effect was apparent in the variation of water temperature, DO, electric conductivity and TSS during the study period. Stratification in the water column was observed in the near dam site every year and vanished between August and October. Increase of nitrogen nutrients was observed when inflowing discharge was low, while phosphorus increase was distinct both during the early season with increase of inflowing discharge and the period of severe draught persistent. Duration persisting high concentration of Chl-a (>25 mg m-3: the eutrophic status criterion, OECD, 1982) was 1~2 months of the whole year in 2014~2015, while it was almost 4 months in 2013. Water quality of Euiam Reservoir appeared to be affected basically by geomorphology and source of pollutants, such as longitudinally linked instream islands and Aggregate Island, inflowing urban stream, and wastewater treatment plant discharge. While inflowing discharge from the dams upstream and outflow pattern causing water level change seem to largely govern the variability of water quality in this particular system. In the process of spatiotemporal water quality change, factors related to climate (e.g. flood, typhoon, abruptly high rainfall, scorching heat of summer), hydrology (amount of flow and water level) might be attributed to water pulse, dilution, backflow, uptake, and sedimentation. This study showed that change of water quality in Euiam Reservoir was very dynamic and suggested that its effect could be delivered to downstream (Cheongpyeong and Paldang Reservoirs) through year-round discharge for hydropower generation.

Modified coagulants were investigated for the removal of phosphorus from secondary effluent of wastewater treatment. The modified coagulants were prepared by mixing alkali earth metal ions such as calcium and magnesium. The basicity of a coagulant influenced on the removal of phosphorus, and coagulants with basicity of 5.9% showed a better removal of total phosphorus than that of 38.5%. Also, coagulants with alkali earth metals enhanced the performance of coagulation by 10% and resulted in 67.1% for total phosphorus removal. Moreover, the removal of suspended solids and chemical oxygen demand was improved using coagulants with low basicity and earth metal ions. Results of this study demonstrated that the use of coagulants with low basicity, and calcium and magnesium ions is recommended to improve wastewater effluent quality.

오디를 포함한 베리류의 건강 기능성이 알려지면서 생산량 증가 및 가공식품 개발이 활발해지고 있지만 베리류과실의 특성상 상처 입거나 무르기 쉬워 생과로 유통되기 보다는 다양한 형태의 가공품으로 유통되고 있다. 베리류를 원료로 식물발효액을 제조하기도 하는데 대부분 소규모 이루어져 원료의 안전성 및 제조과정에 대한 위생관리가 시급하다. 본 연구는 오디 발효액 제조에 사용되는 원물이 유해 세균에 오염되었을 경우와 발효액으로 소량 포장되는 단계에서 유해 세균에 오염되었을 경우에 오디 발효액 발효과정 중 그리고 오염 발효액 보관과정 중 오염세균의 세균수 변화를 조사하기 위해 수행되었다. 오디 발효액이 발효되는 동안 원물에 접종된 E. coli는 시간이 지나면서 감소하는 양상이었다. 특히 오디 원물의 무게 대비 100%로 설탕을 혼합한 처리구 보다는 80%로 혼합한 처리구에서 E. coli의 세균수 감소가 급격하였는데, 설탕을 원물 무게의 80%로 혼합하였을 때 발효과정 중 생기는 총산도가 100% 혼합처리구보다 높음으로써 결과적으로 발효액의 pH가 낮아지게 되어 발생한 결과인 것으로 판단된다. 발효가 완료되어 발효액으로 제품화되는 과정에서 식중독세균에 오염되었을 경우에는 접종 균주별로 조금씩 다른 세균수 감소 양상을 보였지만 대체적으로 보관시간이 지남에 따라 감소하는 양상이었고, 특히 30℃에서 보관하였을 때에는 실험균주 모두 4일 이내에 사멸하였다. 따라서 오디 발효액 제품화시 소량 포장 후 30℃의 온도에서 일주일 정도 보관하는 것이 오디 발효액의 미생물학적 안전성을 높이는데 도움이 될 것으로 판단된다.