사탕무씨스트선충(Heterodera schachtii)은 최근 우리나라의 배추 재배지의 문제선충이다. 본 연구는 사탕무씨스트선충의 밀도와 배추의 묘 령이 사탕무씨스트선충의 증식에 미치는 영향을 알아보기 위하여 수행하였다. 접종농도가 높은(4마리 유충 또는 알/g 토양) 처리에서 씨스트 수나 암컷 또는 알 수가 유의하게 높았다. 40일 묘령 배추에 고밀도 선충 접종 시 30일이나 60일 후 다른 어린 묘령 배추(파종처리, 20일묘, 30일묘)에 비하여 증식 선충 밀도가 높았다. 높은 선충 밀도 조건에 묘령이 오래 된 모종 식재 시 선충 증식율이 높기 때문에 사탕무씨스트선충 관리를 위해서 는 정식 모종의 묘령 고려가 필요하다.
유기합성 농약의 과다사용은 환경오염, 살충제 저항성 발달, 비표적 생물에 대한 영향 등 부작용의 원인이 되고 있다. 유기합성 농약의 대체약 제로 포유동물에 저독성인 식물기원 물질이 각광을 받게 되었다. 이란 서양가새풀(Achillea millefolium L.) 정유성분의 훈증독성은 국제적 저장작 물 해충인 머리대장가는납작벌레(Oryzaephilus surinamensis L.)의 방제제로 연구된 바 있다. 이 식물 정유의 화학적 성분을 가스크로마트 그래피 (MS)를 이용하여 분석하였다. 살충실험 결과 처리농도에 따라 유의한 살충률을 나타냈다. 처리농도와 살충률 간 양의 상관관계가 있었다. 반치사 농도(LC50)는 17.977 μl/L 이었다. 주요 성분은 1,8-Cineole (13.17%), nerolidol (12.87%), α-cubebene (12.35%), artemisia ketone (6.69%), α-terpineol (5.27%), alloaromadendrene oxide (4.71%) 및 borneol (3.99%) 이었다. 전체 동정된 화합물의 96.35%는 Terpenic 화합물로 monoterpene hydrocarbons (8.19%), monoterpenoids (44.23%), sesquiterpene hydrocarbons (21.69%) 및 sesquiterpenoids (22.24%)를 포함하고 있었다. 본 결과는 terpene이 풍부한 서양가새풀 정유가 머리대장가는납작벌레의 안전한 생물농약으로 고려될 수 있음을 보여주었다.
수소원자는 금속 표면에 흡착하여 해리되고 금속격자 사이를 이동해 다시 수소분자로 재결합되어 탈착할 수 있으며 이러한 과정으로 수소는 금속을 통해 투과할 수 있다. 특히 수소원자는 팔라듐에서 높은 용해도와 이동도를 보여 우수한 수소투과 특성을 나타낸다. 본 연구에서는 무전해 도금을 이용하여 Pd계 금속을 α-Al2O3 중공사막 지지 체에 증착시켜 수소투과 실험을 진행하였다. Pd을 증착하기 전, Seeding 과정을 통해 지지체에 Pd 핵을 심어 금속의 증착이 용이하도록 하였으며, 중공사막 지지체의 표면 특성에 따른 Pd 증착상태를 확인하였다.
PURPOSES : The objective of this study is to develop a simple regression model in designing the asphalt concrete (AC) overlay thickness using the Mechanistic-empirical pavement design guide (MEPDG) program. METHODS: To establish the AC overlay design equation, multiple regression analyses were performed based on the synthetic database for AC thickness design, which was generated using the MEPDG program. The climate in Seoul city, a modified Hirsh model for determining dynamic modulus of asphalt material, and a new damaged master curve approach were used in this study. Meanwhile, the proposed rutting model developed in Seoul city was then used to calibrate the rutting model in the MEPDG program. The AC overlay design equation is a function of the total AC thickness, the ratio of AC overlay thickness and existing AC thickness, the ratio of existing AC modulus and AC overlay modulus, the subgrade condition, and the annual average daily truck traffic (AADTT). RESULTS: The regression model was verified by comparing the predicted AC thickness, the AADTT from the model and the MEPDG. The regression model shows a correlation coefficient of 0.98 in determining the AC thickness and 0.97 in determining AADTT. In addition, the data in Seoul city was used to validate the regression model. The result shows that correlation coefficient between the predicted and measured AADTT is 0.64. This indicates that the current model is more accuracy than the previous study which showed a correlation coefficient of 0.427. CONCLUSIONS: The high correlation coefficient values indicate that the regression equations can predict the AC thickness accurately.
팥바구미(Callosobruchus chinensis)는 팥 종실의 이용성을 제한하는 가장 주요한 해충으로 팥 성숙기에 팥 종실의표면에 산란하고 부화유충은 곧바로 종실 안으로 들어감으로 수확한 팥은 이미 팥바구미에 감염된 상태이다. 그래서팥을 상온에 두면 팥에서 팥바구미가 출현하여 팥을 이용할 수 없게 된다. 따라서 상온에서 팥바구미로부터 팥을안전하게 보관할 수 있는 방법을 강구하고자 실내에서 탈산소제, 제습제 및 가스제거제를 이용하여 팥바구미 감염팥에서팥바구미의 출현을 조사하였다. 팥바구미 알을 가진 팥 종실에 탈산소제, 가스제거제, 제습제, 탈산소제+가스제거제,탈산소제+제습제, 가스제거제+제습제 처리에 따른 팥바구미 성충의 출현율은 각각 10%, 36,7%, 0.0%, 10.0%, 3.3%,13.3% 이었다. 팥바구미 유충감염 팥종실에서 탈산소제, 가스제거제, 제습제, 탈산소제+가스제거제, 탈산소제+제습제,가스제거제+제습제 처리에 따른 팥바구미 성충의 출현율은 각각 83.3%, 75.0%, 33.3%, 90.0%, 26.7%, 55.0% 이었고,팥바구미 번데기감염 팥종실에서 탈산소제, 제습제, 탈산소제+제습제 처리에 따른 팥바구미 성충의 출현율은 각각36.7%, 43.3%, 30.0% 이었다. 그리하여 팥바구미 성충의 출현율은 탈산소제와 제습제 조합 처리에서 현저히 낮았으며,특히 팥바구미 알처리에서 가장 낮았고, 다음은 번데기로 나타났다. 따라서 탈산소제와 제습제를 팥과 함께 용기에넣고 밀봉하면 팥바구미의 발육 및 증식을 억제하여 팥바구미로부터 팥을 안전하게 보관할 수 있을 것으로 여겨진다.
남한산 큰자색호랑꽃무지는 그 동안 일본에 분포하는 Osmoderma opicum으로 동정되어 왔으며, 국내에서는 그 희귀성에 의해 멸종위기종으 로 다루어지고 있지만, 남한 개체군에 대한 면밀한 종의 실체에 대한 구명은 없었다. 이에 대해, 남한산 큰자색호랑꽃무지와 유라시안 근연종에 대 해 형태 및 COI유전자 염기서열을 비교를 실시하였다. 결과적으로, 남한산 개체군은 형태적으로 극동러시아에 분포하는 O. caeleste와 동일하였다. 따라서, 남한산 큰자색호랑꽃무지는 O. caeleste임을 제안한다.
A class of phenolphthalein anilide based poly(ethersulfone) (PES) block copolymers containing pendent quaternary ammonium (QA) groups was prepared as anion exchange membranes by reaction involving nucleophilic substitution, benzylic bromination, quaternization and anion exchange with hydroxide ions. Hexafluorobenzene (HFB) was utilized as a linkage group between the hydrophobic and hydrophilic oligomer blocks. Nano-phase separated membrane morphology due to block structure of poly (ethersulfone) serves for better management of absorbed water for higher hydroxide conductivity with good thermal, and dimensional stability. The water uptake, swelling ratio, conductivity, and chemical stability of the copolymer membranes were comparatively investigated.
Geotextile tubes are excellent design strategies for both shoreline protection and dewatering of fine materials. A difficulty with regard to designing geotextile tubes is the matching of the appropriate fabric with the site-specific infilled material and the unavailability of a test to determine the soil-geotextile consolidation properties. Existing methods simulate and predict the final tube shape based on the initial and final unit weights of the infill but the time required to reach the final shape or the compatibility of the infill are not being considered. This study proposes an improved hanging bag test to evaluate the compatibility of an infill with the geotextile fabric, and at the same time, to obtain the soil-geotextile consolidation properties. With the obtained consolidation properties, a big prototype simulation was possible, explaining the deformation behavior of the tube in the field. An analytical procedure used in modeling the tube was coupled with the large strain consolidation theory to simulate the filling and dewatering process.
Reactive oxygen species (ROS) induces oxidation against various biomolecules including fatty acids. Calcium-independent cellular phospholipase A2 (iPLA2) has been known to function maintenance of fatty acids in phospholipids in mammals. An insect iPLA2 (Pi-iPLA2) was predicted from transciptomes of the Indianmeal moth, Plodia interpunctella. It was expressed in all developmental stages from egg to adult. RNA interference (RNAi) against Pi-iPLA2 was performed with specific double-stranded RNA (dsRNA) with more than 70% efficiency in reduction of its expression. Under this RNAi condition, P. interpuctella exhibited developmental retardation with significant accumulation of lipid peroxidation measured by the amount of melondialdehyde
톱다리개미허리노린재는 3월 중·하순부터 11월 중·하순까지 지속적으로 발생하며, 월동성충은 5월 상순, 1회 성충은 8월 하순에 발생피크를 나타내고, 여름철을 제외하고는 농경지보다 산림지에서 발생량이 현저히 많았다. 월동한 톱다리개미허리노린재는 5월 중순경에 산란하고, 5월 하순부터 부화하여 1회 성충이 7월 하순에 콩포장으로 가장 많이 비래한다. 콩포장에서 톱다리개미허리노린재는 일반적으로 개화기부터 발생하기 시작하고, 꼬투리가 달리는 시기부터 발생량이 크게 증가하여 수확기까지 지속적으로 발생한다. 집합페로몬에 의한 톱다리개미허리노린 재의 유인효과는 3성분(EZ:EE:MI)보다 4성분(EZ:EE:MI:OI)에서 약 30% 이상 많이 유인되며, 집합페로몬과 두류종실 을 조합하면 노린재의 유인효과가 약 39∼60% 정도 증가하는데, 특히 청자콩과의 조합에서 유인효과가 가장 높았다. 톱다리개미허리노린재의 일주활동시간대는 8월에는 14:00∼16:00에, 9월 하순부터는 12:00∼14:00에 가장 많이 유인 되어 계절에 따라 차이가 있었다. 트랩의 종류에 따른 톱다리개미허리노린재의 유인효과는 기존의 통발트랩보다 로케트트랩에서 1.5배 이상 많이 유인되었으며, 로케트트랩의 내부에 솔라팬을 장착하면 노린재의 유인효과는 1.9배 이상 증가하였고, 여기에 LED를 장착하면 노린재의 유인효과는 1.8배 증가되었다. 또한 로케트트랩의 날개판 하부에 안착판을 추가하면 노린재의 유인효과 25% 이상 증가되었다. 로케트트랩에 이종 노린재류의 집합페로몬을 동시에 주입하여도 대상 노린재류의 유인효과가 간섭받지 않고 잘 유인되었다.
Riboswitches are structured RNA motifs that can directly bind specific metabolites. The binding of metabolites further regulates downstream metabolism eliminating the need for any regulatory proteins. We searched for novel bacterial vitamin B1 binding riboswitches in the metagenome of sun-dried saline soil. Soil microbial metagenomes were studied using NGS analysis. A total of approximately 50 Gb of the sequence data was obtained by Hi-seq and 454 GS FLX sequencing, and these sequences were subjected to riboswitch search. Hi-seq generated 614 contigs showing similarity to riboswitches, while 454-based sequencing generated 383 similar contigs. We matched whole metagenome contigs to local BLAST databases constructed using 91 previously known bacterial vitamin B1 thiamine pyrophosphate (TPP)-box motifs, and 11 SAM S-box motifs. Repetitive BLAST comparisons to local BLAST databases with nucleotide sequences from NGS identified 14 novel TPP-box motifs, and 7 S-box motifs respectively from the metagenome contigs. Further, RNA secondary structure analysis with public databases Rfam, and RibEx using these 21 riboswitch candidates revealed one contig, D8PYI to possess the most probable TPP-box structure. We constructed intragenic synthetic riboswitches to investigate whether the TPP-box motif region in D8PYI could harness gene expression in the presence of TPP. Construction of biosensors containing 100~400 bp fragments of D8PYI contigs, and in vivo imaging using the biosensors displayed TPP-specific changes in the expression of a green fluorescence protein reporter. In this regard, the adaptation of in silico riboswitch screening from environmental metagenomes could provide biosensors for detection of specific metabolites.
This study was performed to investigate the nutrition knowledge, dietary attitudes, and dietary behaviors among high school students by gender. The subjects were 275 students (127 male, 148 female) in Incheon metropolitan area. Selfadministered questionnaires consisted of general characteristics and anthropometric data, nutrition knowledge, dietary attitudes, and dietary behaviors. The average score of nutrition knowledge was significantly higher in female subjects (9.4) compared to male subjects (8.2) (p<0.01). Male subjects had a higher score for dietary attitudes than female subjects (p<0.001). Frequency of meals was significantly higher in male subjects compared to female subjects (p<0.05). Duration of meal time in male subjects was significantly higher (‘5-10 minutes’) compared to female subjects (p<0.001). Unbalanced diet was significantly higher in female subjects (66.3%) compared to male subjects (48.9%) (p<0.01). Male subjects showed significantly higher consumption frequency of ‘dairy’ (p<0.001) and ‘beans’ (p<0.001) compared to female subjects. For snack consumption, male subjects showed higher consumption frequency of ‘nuts’ (p<0.001), ‘soda’ (p<0.05), ‘fast foods’ (p<0.001), and ‘ramyeon’ (p<0.01), but lower consumption frequency of ‘biscuits and bakery’ (p<0.01) compared to female subjects. Therefore, it is necessary to develop a systemic nutrition education program for high school students by gender.
Particle morphology change and different experimental condition analysis during composite fabrication process by traditional ball milling with discrete element method (DEM) simulation were investigated. A simulation of the three dimensional motion of balls in a traditional ball mill for research on the grinding mechanism was carried out by DEM simulation. We studied the motion of the balls, the ball behavior energy and velocity; the forces acting on the balls were calculated using traditional ball milling as simulated by DEM. The effect of the operational variables such as the rotational speed, ball material and size on the flow velocity, collision force and total impact energy were analyzed. The results showed that increased rotation speed with interaction impact energy between balls and balls, balls and pots and walls and balls. The rotation speed increases with an increase of the impact energy. Experiments were conducted to quantify the grinding performance under the same conditions. Furthermore, the results showed that ball motion affects the particle morphology, which changed from irregular type to plate type with increasing rotation speed. The evolution was also found to depend on the impact energy increase of the grinding media. These findings are useful to understand and optimize the particle motion and grinding behavior of traditional ball mills.
Membrane based water and wastewater treatment becomes more and more popular; however, membrane fouling is still a critical obstacle for its extensive use. Most of the membranes being used are polymeric and have limitations in physical, chemical, and thermal stability, even though various novel materials were introduced. In this study, metal membranes were fabricated to solve those weak points of polymeric membranes. We evaluated the physical properties of a metal membrane, such as pore size distribution, surface morphology, and water flux, and finally used the membrane for electrochemical oxidation of municipal wastewater with simultaneous hydrogen fuel generation. The metal membrane removed 50-70% of the feed organic matter by electrochemical oxidation; 10-30 % removal by electrochemical oxidation plus 40% by membrane rejection.
이산화염소는 살충효과를 지니며, 이는 이 물질이 발생시키는 활성산소에 기인된다. 살충효과를 주는 주요 원인으로 이산화염소의 세포독 성에 주목하고 있다. 본 연구는 이산화염소가 유발하는 세포독성이 활성산소에 기인한 아폽토시스 유발로 가설을 세우고 이를 검증하였다. 화랑 곡나방(Plodia interpunctella) 유충에 이산화염소를 주입한 결과 전체혈구수의 뚜렷한 감소를 보였고, 이후 처리 유충은 사망하였다. 아폽토시스 세포치사과정을 규명하기 위해 TUNEL (terminal deoxynucleotidyl transferase nick end translation) 분석법을 적용하였다. 곤충 세포주의 하나인 Sf9 세포에 서로 다른 이산화염소를 처리하고 TUNEL 분석법으로 관찰한 결과 처리 농도에 비례하여 아폽토시스 비율이 증가하였다. 다 음으로 서로 다른 농도의 이산화염소를 화랑곡나방 유충에 주입하고 혈구 세포를 TUNEL 분석법으로 관찰한 결과 이산화염소는 처리 농도에 비례하여 아폽토시스 유발을 나타냈다. 그러나 항산화제인 비타민 E를 이산화염소와 함께 처리하면 비타민 E의 농도에 비례하여 이산화염소의 아폽토시스 유발을 억제하고 이에 따라 살충률도 감소하였다. 이러한 결과는 이산화염소에 기인한 세포독성은 활성산소에 기인한 아폽토시스 유 발로 이뤄졌다는 것을 제시하고 있다.
In the current study, oxidative decomposition of a volatile organic compound was investigated at room temperature and pressure. The experiment was carried out in lower ethylene concentration and with various higher gas flow rates. The reactor has 7 different compartments in which the reaction takes place independently. Plasma was generated inside each compartment by the application of alternating current (AC) voltage. 5 wt% manganese loaded and 5 wt% silver loaded 13X zeolite were used as catalysts. Bare zeolite showed higher ethylene decomposition efficiency than Ag loaded and Mn loaded zeolite. Ozone concentration was increased slightly while increasing the SIE, reached a maximum and started decreasing. Ag loaded zeolite also showed similar decomposition efficiency, but the concentration of ozone was greatly lowered.
In this study, Stockbridge damper was adopted to reduce the reponses of structures under earthquakes. A finite element analysis software, SAP2000, was used to simulate the structural response and the control device under dynamic loads. A 3 story frame model and the proposed control device, Stockbridge damper, were designed under laboratory conditions. In this research, a pendulum type tuned mass damper (PTMD) was also adopted in order to compare with the Stockbridge damper. Harmonic loads were applied to verity the control performance of both control devices in each mode. In results, it has been found that the Stockbirdge damper decreases significantly the responses of the structure more than the PTMD under the harmonic loadings. The El Centro and Northridge earthquakes were also applied in order to investigate the performance by both control devices. The responses of the building demonstrate that the Stockbridge damper reduces the response of the building structure during earthquakes more effectively than the PTMD.