In this study, a system was developed that can evaluate the radon gas removal efficiency of air cleaner filters. The system has three acrylic chambers connected in series;: the 1st chamber, the filter chamber and the 2nd chamber. In the 1st chamber, a radon source and an air pump were installed to create an environment with a constant radon concentration. Radon concentration in the two chambers was continuously monitored by ionization chamber detectors(RD-200, FRD1600, FTLab, Korea) and, in the 2nd chamber, the radon concentration increase of air filtrated by each filter was inter-compared. HEPA filters and two honeycomb type filters were evaluated. Results of HEPA filter, GAC 1 and GAC 2 were 1142 Bq, 7016 Bq and 12053 Bq, respectively. HEPA filter showed a significantly lower capacity for radon removal than the GAC filters. Also, the GAC 2 filter showed a more than 70 % better result compared to GAC 1 due to the difference in filter materials. Therefore, this system can be used to evaluate the radon removal ability of air cleaner filters, by filter type and filter material.
호박꽃과실파리(Bactrocera scutellata)는 호박꽃을 가해하는 해충이다. 이들 수컷은 식물체 유래물질인 raspberry ketone (RK)에 유인되 어 섭식하는 습성을 지니고 있다. 본 연구는 이 해충의 방제를 위해 수컷박멸기술(male annihilation technique: MAT)을 개발하는 데 목표를 두고 이를 위한 기반 기술을 탐색하였다. 효과적 유인 물질이 실내 및 실외 실험을 통해 비교되었다. 일반적으로 과실파리류에 유인효과가 높은 methyl eugenol에 호박꽃과실파리 암수는 모두 반응하였으나 야외에서는 전혀 유인효과가 나타나지 않았다. RK의 합성 유도체인 cuelure (CL)에 호박꽃과실파리 수컷은 실내 및 야외조건에서 모두 높은 유인효과를 나타냈다. 그러나 본 연구에서 지향하는 왁스형 방출기 조건에서 RK가 CL에 비해 동등하거나 우수한 유인효과를 보였다. MAT를 구성하는 데 유인 물질과 함께 포함될 살충제를 피레스로이드 살충제로 선발 하였다. 또한 MAT 처리 후 치사된 개체의 확인과 계수를 위해 깔때기형 트랩을 선발하였다. 이러한 결과를 종합하여 본 연구는 호박꽃과실파리 의 MAT 기술은 RK과 비펜스린을 담은 왁스형 방출기로 결정하고 이를 깔때기트랩에 설치하도록 구성하였다. 이러한 기본 조건은 추후 현장 적 용할 MAT 기술 개발에 기반 정보로 이용될 수 있다.
In this paper, a study on noise reduction characteristics of the precast floating track system, being developed as measures to mitigate noise and vibration of existing as well as constructing elevated railroad stations, is presented using numerical analysis. One of the most prominent sound analysis program, Virtual Lab., is utilized in investigating noise reduction performance of the precast floating track system, and structural velocity data, obtained from vibration analysis on a model-updated elevated railroad station considering vehicle-track-structure interaction, are used for the input of the sound analysis. The sound analysis is performed using the finite element method, and noise reduction performance before and after installing the precast floating track system is compared at three enclosed areas in the Daecheon Station, selected as a representative of elevated railroad stations in this nation. From the comparison result, it is seen that the precast floating track system can decrease noise by average of 5dB∼8dB when the Saemaeul train passing through the station and 10dB∼15dB when the KTX train passing through. Also, the noise reduction characteristics is different depending on the type of train and the distance from the track.
본 연구는 반추동물용 섬유질배합사료(TMR) 제조업체 의 사료안전관리 인식 및 사료 중 위해인자 오염도를 조사 하기 위해 138개소 TMR 제조시설을 대상으로 약 10개월 동안 설문조사를 실시하였다. 조사표는 총 17개 문항으로 구성하였으며, 얻어진 자료는 기술통계분석, 교차분석 및 신뢰도 검정을 통해 분석하였다. TMR 제조시설의 평균 일 일 생산능력은 81.38톤 이었다. 평균 개업연도는 2004년 및 종사인원은 13.7명이었고, 유통경로는 직접거래가 80.4%로 가장 많았다. 사료안전관리 시스템 도입은 사료안전관리의 제도적 여건이 조성된 후 도입이 필요하다는 인식이 주를 이루었으며, 사료안전관리 시스템 구축을 위해서는 사료안 전정보 제공 및 공유가 가장 필요한 조건으로 나타났다. 사료안전성 및 위해물질 관리에 가장 취약한 분야는 곰팡 이 독소인 것으로 조사되었으며, 사료 제조과정에서 가장 위험한 위해인자는 쇠, 파편, 흙 등과 같은 이물질로 나타 났다. 사료 중 위험인자 오염도 조사에서 카드뮴, 비소 및 셀레늄은 허용기준치를 초과한 제품이 일부 조사되었고, 오크라톡신류 및 아플라톡신류는 허용범위내로 조사되었 다. 잔류농약, BSE, 푸모니신 및 살모넬라는 검출되지 않았 으며, 멜라민 및 비단백태질소화합물은 각각 11.35ppm 및 5%로 최댓값을 나타냈다. 규모별 TMR 제조시설의 사료 내 위해인자 오염도는 규모별로 차이가 많았으며, 같은 규 모 내에서도 제조시설에 따라 위해인자의 검출량이 다르 게 나타났다. 또한 소규모에 비해 중규모 및 대규모에서 위해인자 검출량이 더 높아지는 경향을 보였다. 따라서 본 조사결과 TMR 제조시설의 사료안전관리 시스템을 구축하 기 위해서는 사료안전에 대한 정보제공 및 공유가 정책적 으로 제도화되어야 하고, 사료 내 발생하는 곰팡이 독소방 지 및 이물질 제거를 위한 사료관리법의 강화와 원료 공급 처에서 이물질을 제거할 수 있는 장치 도입을 의무화할 필 요가 있다고 판단된다.
Cryopreservation of germ cells from genetically proven animals could be a source of restoration tools from the risk of extinction or disappearance of wanted characteristics. Using frozen semen, the genetic gains of Korean native cattle have been increased greatly for 70 years. The preservation of genetic resources as a form of frozen semen straw has limited availability due to the numbers. To circumvent this weakness of frozen semen, we tested two re-freezing methods with different initial thawing temperatures using frozen Korean proven semen and rare breed semen from albino, black and chikso breeders. It has been known that human sperm could resist to cryo-damages by repeated freeze-thaw cycles, but not for Korean proven bulls number (KPN) or for rare breeds. Total 7 frozen semem from brindled(2), black(1), Korean Albino(2) and KPN(1) bulls were used for our research. After thawing straws under 5°C/2min or 37°C/40sec with low temperature water bath and thermo jug, spermatozoa were re-diluted with triladyl diluents after first thawing and re-frozen. Sperm motilities were compared between animals and treated groups after re-thawing. Mean values of motility and viability of refrozen/thawed sperm for expansion of the number of straws were significantly higher in 5°C than in 37°C (P< < 0.05). However, the activity of viable sperm thawed at 5°C was significantly decreased after first and second thawing. It is estimated that re-freezing of frozen semen from rare Korean native cattle is possible with resistant properties of survived spermatozoa.
This study was to develop the products that the Lamp and Ballast are combined for the purpose of easy installation to complement the difficulty of the installation process due to the structure of existing product which the lamp and the Ballast are separated, and that have 8-wavelengths dual-lamp structure such as solar, an advantage of more than 3 times longer life than fluorescent lamp and immediately lighting. This study developed the commercialized products that can prevent the environmental pollution caused by low efficiency and short life time of existing Lamps, and can replace the LED Lighting products which has high Glare index with high price, has also developed the variety of application for industrial, commercial, indoor and military. The applied product are Street lights, Security lights, Flood lights, Indoor lights and lights for fishing. This study solved the optimum distribution and placement of components considering the lightest weight first and thermal interference caused by combination of lamp and ballast by thermal release through applying the double bulkhead design of ballast box, and implemented the high efficiency Eco-friendly products with excellent visibility which can be applied and used for indoor and outdoor both place through high temperature and high humidity test, which has an advantage of 8-wavelengths of same spectrum of solar through the initial trial production.
This study carried out and analyzed survey data on captains and mates of Korean coastal large trawlers in order to examine factors affecting body abnormalities and fatigue on bridge teams from work and environment at bridges of trawlers. The summarized result may be summed up as follows: multiple regression analysis with body pain and fatigue as dependent variables yields t-values of –2.559 (p<0.05) and –3.928 (p<0.05) respectively. From the result, environment at bridges (views, spaces and exhaust) were negative factors in affecting bridge workers’ pain and fatigue. Thus, it is determined to secure available spaces to improve the workers’ views through windows in front of, besides and rear bridge and create more pleasant atmospheric environment at bridge.
This study describes the effects of polyurethane/loess powder (PU/LP) nanofiber thin films composite produced from electrospun for absorption volatile organic compounds (VOCs) from air. Environmental issue has become a focus with improving people's living quality. The VOCs are one of the factors that affect the environmental safety. So, in order to improve the environment and safety for people, many air cleaning techniques have been investigated. One of the methods is nanofiber filtration technology. In this study, the PU nanofiber thin film has been studied that it has the adsorption of VOCs capacity, and LP nanoparticles (NPs) can be used as an additive to load into PU nanofiber thin film by electrospinning. For studying PU/LP nanofiber thin films's absorption of VOCs capacity, 4 samples (0, 10, 30, and 50 wt% LP with respect to PU) were manufactured, respectively. The results show that PU composite mats containing 30 wt% LP NPs has the highest VOCs absorption capacity, and the adsorption capacity for toluene was the highest compared to benzene and chloroform.
In this study, we aimed to develop a mixed tea prepared with roasted mulberry leaf and fruit using response surface methodology (RSM). Roasting of mulberry leaf was by 6 stages, as shown in Fig. 1; and mulberry fruit was roasted in 4 stages, as shown in Fig. 2. Subsequently, physicochemical measurements such as total polyphenol content, nitric oxide production content, and α-glucosidase inhibitory effect were obtained for each sample. Central composite design was applied to prepare samples containing varying contents of roasted mulberry leaf (RoML) and roasted mulberry fruit (RoMF); subsequently, sensory evaluation was conducted. The total polyphenol content of roasted samples (RoML and RoMF) were significantly higher than that of raw samples (RaML and RaMF), respectively. The nitric oxide (NO) production of roasted samples were significantly lower than that of control (LPS induced RAW 264.7 cell). The α-glucosidase inhibitory effect of roasted samples was significantly higher than that of raw samples, respectively. Based on the RSM estimation for determination of optimum ratio by sensory evaluation (taste, color, and flavor) among 13 mixed samples, the optimum mixing ratio of RoML and RoMF for taste, color, and flavor were 1.64 g (RoML) and 0.88 g (RoMF), 1.35 g (RoML) and 0.92 g (RoMF), 1.65 g (RoML) 1.03 g (RoMF), respectively. Based on results of three sensory evaluations, mixing ratio comprising 1.54 g of RoML and 0.92 g of RoMF is desirable for delicious tea with functionality.
The objectives of this study, which filled gaps in previous studies, were: (1) to find the optimal mixing condition of nanoemulsions containing oleoresin capsicum (OC), Tween 80, propylene glycol (PG), and sucrose monostearate (SES) by microfluidization; (2) to investigate their properties and stability depending on such factors as pH, temperature, and heating time; (3) to measure the effect of adding ascorbic acid. In order to test these objectives, the following three experiments were conducted: Firstly, in order to find the optimal mixing ratio, nanoemulsions containing OC - the mean diameter of which is smaller than 100 nm - were prepared through the process of microfluidization; and their mean particle size, zeta potential, and capsaicinoids were measured. The test results indicated that the mixing ratio at OC : Tween 80 : PG + water(1:2) = 1 : 0.2 : 5 was optimal. Secondly, the properties and stability of nanoemulsions were investigated with varying parameters. The test results illustrated that single-layer nanoemulsions and double-layer nanoemulsions coated with alginate were stable, irrespective of all the parameters other than/except for pH 3. Thirdly, the properties of nanoemulsions were then analyzed according to the addition of ascorbic acid. The results demonstrated that the properties of single-layer nanoemulsions were not affected by addition of ascorbic acid. In case of alginate double-layer nanoemulsions, the particle size was reduced, and zeta potential increased with the addition of ascorbic acid. In conclusion, the demonstrated stability of various nanoemulsions under the different conditions in the present study suggests that these findings may constitute a basis in manufacturing various food-grade products which use nanoemulsions-and indicate that food nanoemulsions, if adopted in the food industry, have the potential to satisfy both the functionality and acceptability requirements necessary to produce commercially marketable food-grade products.
In this study, we designed the 3-dimensional tire mold according to the A automobile company’s tire model, and analysed the distribution of temperature of mold using the numerical method when the heat flux and heat transfer time at the surface of tire mold were changed. A analysis region of mold was the 1/16 of entire mold, and the grid number was about more than 880 thousand. In order to analyze the temperature change of mold, the thinnest part of the mold was chosen as the research object, and then the temperature of 6 points on the vertical downward direction of the thinnest part was analyzed with the time change. While the numerical condition was that heat flux was 321,200 W/m2, 440,000 W/m2 and 880,000 W/m2, and measuring time was 0.1 second, 0.2 second, 0.5 second and 1 second, respectively. As a result, the temperature difference between the surface temperature and the lowest temperature of mold was 7.3℃ when the heat transfer time was 0.1 second. Also, the minimum temperature difference was almost 0.11℃ when the heat transfer increased to 1 second. It can be explained that the main material of tire mold was aluminum and its thermal conductivity was high (k=140 W/m·K). In addition, when the heat transfer time was more than 1 second, the heat flux of mold surface will be transmitted at the inside of the thinnest part, and the heat transfer will be a marked difference according to the shape of the thinnest part.
Gas hydrate (GH)-based desalination process have a potential as a novel unit desalination process. GHs are nonstoichiometric crystalline inclusion compounds formed at low temperature and a high pressure condition by water and a number of guest gas molecules. After formation, pure GHs are separated from the remaining concentrated seawater and they are dissociated into guest gas and pure water in a low temperature and a high pressure condition. The condition of GH formation is different depending on the type of guest gas. This is the reason why the guest gas is a key to success of GH desalination process. The salt rejection of GH based desalination process appeared 60.5-93%, post treatment process is needed to finally meet the product water quality. This study adopted reverse osmosis (RO) as a post treatment. However, the test about gas rejection by RO process have to be performed because the guest gas will be dissolved in a GH product (RO feed). In this research, removal potential of dissolved gas by RO process is performed using lab-scale RO system and GC/MS analysis. The relation between RO membrane characteristics and gas removal rate were analyzed based on the GC/MS measurement.
Stable Isotope Analysis (SIA) of carbon and nitrogen is useful tool for the understanding functional roles of target organisms in biological interactions in the food web. Recently, mixing model based on SIA is frequently used to determine which of the potential food sources predominantly assimilated by consumers, however, application of model is often limited and difficult for non-expert users of software. In the present study, we suggest easy manual of R software and package SIAR with example data regarding selective feeding of crustaceans dominated freshwater zooplankton community. We collected SIA data from the experimental mesocosms set up at the littoral area of eutrophic Chodae Reservoir, and analyzed the dominant crustacean species main food sources among small sized particulate organic matters (POM, <50 μm), large sized POM (>50 μm), and attached POM using mixing model. From the results obtained by SIAR model, Daphnia galeata and Ostracoda mainly consumed small sized POM while Simocephalus vetulus consumed both small and large sized POM simultaneously. Copepods collected from the reservoir showed no preferences on various food items, but in the mesocosm tanks, main food sources for the copepods was attached POM rather than planktonic preys including rotifers. The results have suggested that their roles as grazers in food web of eutrophicated reservoirs are different, and S. vetulus is more efficient grazer on wide range of food items such as large colony of phytoplankton and cyanobacteria during water bloom period.
This research determined priority of quality improvement of public institution's education service by using ASC for importance and applying Topsis, a multi-standard decision-making method simplifying various attributes and scales of evaluation items and deciding the comparative priority for satisfaction and discussed the differences so as to measure the quality of public institution's educational service and examine the priority of education service' quality improvement. This research classified the characteristics of quality improvement. As a result, it's significant to suggest positive direction and method to improve satisfaction and education service's quality from an angle of demander by analyzing educational satisfaction of education service quality of public education institution and effects on the following improvement.
본 논문은 판자 컬렉션(Panza Collection)에 나타난 이상주의 미학을 당대의 사회 적 맥락 속에서 폭넓게 조명하고자 한 연구이다. 주세페 판자 디 비우모(Giuseppe Panza di Biumo, 1923-2010)는 1957년부터 1999년까지 다양한 형식의 미술작품을 수 집해왔으며, 그 수는 2,500여 점에 이른다. 지금까지의 판자 컬렉션에 대한 선행 연구 는 미학적인 측면에 대한 논의가 주를 이루거나, 1960년대 이후 변화된 전시 방식의 사례 연구에 그친다. 그러나 판자 컬렉션은 한 개인의 미학과 더불어 당대의 현실이 반영된 것이라는 전제에서 본 연구는 시작되었으며, 따라서 컬렉션의 출발점인 이상주 의적인 미학과 그 이면의 상업적 면모라는 양면성을 전시장과 유통과정을 통해 이를 고찰하고자 하였다. 18세기 바로크 양식으로 지어진 빌라 판자 안에서 색채와 형태의 적절한 구성으로 이루어진 판자의 미니멀리즘 회화는 실내 디자인의 요소이자 추상회화로 이루어진 순수 조형적 공간이라는 양면성을 통합한 독특한 전시공간을 만들어낸다. 빌라 판자의 별채 에 전시된 미니멀리즘 설치 작품 역시 실내장식 혹은 건축적 환경을 조성하면서도 동시 에 물성을 초월하는 경험을 제공하기도 한다. 판자는 실제의 건축적 공간에 형광 튜브 를 설치하거나 건축의 물리적 구조 자체를 작품으로 제시하면서 빌라를 하나의 예술적 공간으로 만들었다. 이를 통해 그 공간은 형광튜브의 물성과 빛에서 오는 비물질적인 경험, 실제 공간에 대한 물리적 체험과 그 안에서의 ‘걷는 행위’를 통한 명상적 체험이 공존하는 장소가 되었다. 그의 개념미술 컬렉션에서 나타나는 문자의 반복 역시 이미지의 복제 시스템을 드러 내면서도 단어의 반복으로 인해 일종의 사유의 과정을 이끌어낸다. 이처럼 판자는 실제 의 건축적 공간에 작품을 설치하거나 건축의 물리적 구조 자체를 작품으로 제시하면서 빌라를 하나의 예술적 공간으로 만들었다. 그는 빌라 판자의 전시공간을 통해 삶의 세 속적인 측면까지도 이상화시킨 예술지상주의를 구현한 것이다. 반면 판자 컬렉션의 유통과정에서는 판자의 이상주의 미학의 이면이 구체적으로 드 러난다. 판자는 자신의 미적 취향에 부합하면서도 합리적인 가격일 경우에만 작품을 구 입했으며, 작품을 매매하거나 교환하기도 하였다. 이후 그는 컬렉션을 미국의 주류 미술관에 판매하였으며 순회전을 통해 국제적 명성을 얻게 되었다. 특히 순회전은‘판자 컬렉 션’이라는 라벨과 작품의 설치 및 변경과 관련된 사항에 대해 판자의 의견을 반영하여야 한다는 계약 조건 하에 이루어졌다. 즉, 그것은 일종의 문화상품처럼 유통된 것이다. 이와 같이, 판자 컬렉션의 전시공간에 드러난 이상주의 미학과 그 이면의 상업적 유 통이라는 현실은 미술작품과 그 컬렉션이 순수한 미적 취향의 구현체일 뿐 아니라 당대 사회와의 관계 속에서 형성된 매우 다원적인 성격의 산물임을 드러낸다. 판자는 현실적 인 면모와 예술적인 감성을 모두 갖춘 후기 자본주의 시대의 전형적 컬렉터였으며, 판자 컬렉션의 전시와 유통과정에서 드러난 이상주의 미학과 그 이면 역시 이러한 당대성을 드러내는 하나의 표본과 같은 것이다. 본 연구는 이처럼 판자라는 한 개인의 미적 취향과 그 예술적 발현으로서의 컬렉션 을 당대의 사회적 구조라는 폭넓은 맥락에서 접근하였다는데 그 의의를 둘 수 있다. 즉 판자의 이상주의 미학의 인문, 사회학적 측면을 재고하게 하였다는 점에서 본 논문의 궁 극적인 의미를 찾을 수 있을 것이다.
Simple sequence repeats (SSR), also referred to “microsatellites” consist of tandemly repeated short DNA sequence motifs and have been applied in various marker-based studies. SSRs were isolated and characterized from ‘Heuktari’ and ‘Miso’, which are major oyster mushroom cultivars in Korea, by genome sequencing and bioinformatic analysis. The genome sizes of ‘Heuktari’ and ‘Miso’ were estimated to be 40.8 and 40.3 Mb, respectively, which are larger than those of other P. ostreatus species (PC9 and PC10) and smaller than those of P. eryngii (KNR2312P5). In total, 949 and 968 SSRs were found in the ‘Heuktari’ and ‘Miso’ genomes, respectively. Comparative analysis of five mushrooms including P. ostreatus var. florida (PC9 and PC15) and P. eryngii revealed that the number of SSRs in ‘Heuktari’ and ‘Miso’ were the highest among them. All mushrooms studied showed similar SSR distribution patterns. Tri-, hexa-, and octanucleotide motifs accounted for the top three fractions of all SSRs.