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        검색결과 42

        22.
        2015.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        사과 재배포장에서 점박이응애(Tetranychus urticae Koch)의 월동은 사과나무의 여러 장소에서 5~15마리의 성충 암컷이 개체군을 형성하 여 월동하는 것으로 밝혀졌다. 월동중인 암컷들은 대부분 복숭아순나방(Grapholita molesta) 유충의 고치가 있는 조피사이의 갈라진 틈에서도 발 견되었으며, 부주지 상에 형성된 좁은 조피틈과 과실 수확 후 남아있는 꽃자루에서도 발견되었으나 월동 개체수는 매우 적었다. 또한, 월동중인 암컷들은 결과지의 기부에 형성된 거친껍질 및 눈의 기부, 여러 작은가지의 분지부위 좁은틈에서도 발견되었다. 한편, 수체상에 형성된 일부 점박 이응애 월동장소로 죽은 개각충속, 깍지벌레 빈껍질속, 진딧물의 미라속에서도 발견되었는데, 이들 장소에서의 월동 응애수는 매우 적었다. 2년 에 걸쳐 수행된 본 연구에서 점박이응애의 월동중 암컷 성충의 사망률은 평균 72~80%로 매우 높았으며, 이는 이들 응애가 겨울 동안 추위에 견 디는 저항력이 낮기 때문으로 판단되었다.
        4,000원
        23.
        2015.10 구독 인증기관·개인회원 무료
        Since 2000, the damages of hemipteran pests have severely increased. This study was performed to find the proper monitoring methods and investigate seasonal occurrences of the two apple-infesting stink bug species by the year and to evaluate the orchard rate of infestation and rate of damaged apple. Also the preferences of stink bugs to the crabapple cultivars were investigated in orchards. Compared data obtained from monitoring methods using visible counts, aggregation pheromone traps or mercury light traps, the occurrence density of apple-infesting stink bugs (Plautia stali and Halyomorpha halys) could be monitored more effectively in aggregation pheromone trap than visible count or mercury light trap. The occurrence densities of two species during growing season were low in 2013, but increased in 2014. From the investigations at 25 orchards of eight districts was the infestation rate was at 16.7% in 2013 and 62.1% in 2014 . The occurrence density of stink bugs in crabapples was highest in ‘Purple lemoine’ followed by ‘Professor sprenger’ ‘M. baccata’, ‘Robinson crab’, ‘Sandong pingguo’, damaged fruit rate. The number of damaged holes was high in order as ‘Hopa-A’, ‘Sandong pingguo’, ‘Adam’s crab’, ‘Professor sprenger’, ‘Purple lemoine’.
        24.
        2014.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        이 연구는 사과원에서 20년동안 두 종 응애의 밀도변화를 조사하기 위하여 수행하였다. 사과나무를 가해하는 두 종의 응애 해충, 점박이응애 (Tetranychus urticae)와 사과응애(Panonychus ulmi)의 발생을 1992년부터 2011년까지 8개 도시 포함, 한국의 남부지역에 위치한 사과주산지역에 서 조사하였다. 20년간의 추세는 많은 과원이 1992년부터 1999년까지는 점박이응애가 주로 가해를 하였지만 2000년도부터는 사과응애가 우점하 기 시작했다. 사과응애의 평균관찰밀도는 일정했고 점박이응애의 밀도는 이 기간동안 일정하지 않았다. 5년주기별 발생추세 분석은 점박이응애의 밀도가 2002년 이후에 감소하는 것을 보여주었다. 4월부터 9월까지 월별피해과원율과 두종 응애의 평균발생밀도는 사과응애의 밀도가 4월에 높지 만 점박이응애의 밀도가 5월부터 9월까지 높았다. 이런 변화는 살충제 살포횟수, 초경재배관리, 질소비료 사용의 감소와 전체적인 과원관리의 변화 등으로 기인한다. 그러나 이러한 예측은 이를 증명하기 위해 보다 자세한 연구가 필요하다. 본 연구를 통해 비료살표와 같은 재배법과 살충제 살포횟 수와 종합적해충관리 등의 환경적 변화가 사과원에서 두종 응애의 우점종과 발생밀도에 영향을 준 것으로 보인다.
        4,200원
        25.
        2014.10 구독 인증기관·개인회원 무료
        In apple orchards, the damages by woodborers are increased. Mainly infesting woodborers are elucidated three species, namely, the fruit-tree pinhole borer (Xyleborinus saxeseni (Ratzeburg)), black timber bark beetle (Xylosandrus germanus (Blandford)), and Xyleborus apicalis (Blandford). Investigated result from population densities of woodborers using trap at Apple Research Station in Gunwi, Gyeongbuk, X. saxeseni and X. germanus were first captured from late-March and reached highest peak at mid-April. X. apicalis also first captured from late-March and reached highest peak at mid/late-May than April. Entrance hall was first observed from late-March and recorded highest number at April, but steadily decreased. Numbers of entrance hall according to the apple varieties were ordered as ‘Hwangok’ > ‘Fuji’ > ‘Hongro’. Entrance hall by tree height were mainly observed range from 21 to 80 cm (from the ground), found with highest entrance hall at 190 cm. Entrance hall by lateral branch order were mainly occurred at the first lateral branch from the ground, but the entrance hall was decreased as height increased. The ratio of trunk and branch were showed as 6.5 : 3.5.
        26.
        2014.04 구독 인증기관·개인회원 무료
        In the midst of environments with crop-mixing, there were more preferred the fruit trees by brown-winged green (Plautia stali (Scott)), and yellow-brown stink bug (Halyomorpha halys (Stål) and vegetables by Far eastern green stink bug (Nezara antennata Scott) and Bean bug (Riptortus pedestris (Thurnberg)). The major dominant species was identified as P. stali, infesting fruit trees over 99.4% among tested insects. It is severely damaged on peach of middle and late ripening, crab apple, pear and wild fruit of Actinidia arguta. In an investigation for the seasonal occurrence using aggregation pheromone trap, P. stali was peaked with three times at late-May ~ early-June, mid- and late-July, and mid-Sept. ~ Oct. And H. halys slightly peaked at mid-June, and mid- and late-July and increased the occurrence at mid-Sept. ~ mid-Oct. Using seven insecticides - dinotefuran WP, flonicamid WP, etofenprox WP, chlorpyrifos WP, cabaryl WP, chlothianidin SC, and bifenthrin WP - registered on apple, contact and residual toxicity was tested on both male and female of P. stali and H. halys. Contact toxicity of dinotefuran WP was excellent on P. stali but the others had low effect. While all insecticides except flonicamid, residual toxicity were all effective on P. stali. Dinotefuran have a excellent contact toxicity and chlorpyrifos and bifenthrin have good residual toxicity against both male and female of H. halys.
        27.
        2014.04 구독 인증기관·개인회원 무료
        In the midst of environments with crop-mixing, there were more preferred the fruit trees by brown-winged green (Plautia stali (Scott)), and yellow-brown stink bug (Halyomorpha halys (Stål)) and vegetables by Far eastern green stink bug (Nezara antennata Scott) and Bean bug (Riptortus pedestris (Thurnberg)). The major dominant species was identified as P. stali, infesting fruit trees over 99.4% among tested insects. It is severely damaged on peach of middle and late ripening, crab apple, pear and wild fruit of Actinidia arguta. In an investigation for the seasonal occurrence using aggregation pheromone trap, P. stali was peaked with three times at late-May∼early-June, mid- and late-July, and mid-Sept. ∼Oct. And H. halys slightly peaked at mid-June, and mid- and late-July and increased the occurrence at mid-Sept. ∼mid-Oct. Using seven insecticides - dinotefuran WP, flonicamid WP, etofenprox WP, chlorpyrifos WP, cabaryl WP, chlothianidin SC, and bifenthrin WP - registered on apple, contact and residual toxicity was tested on both male and female of P. stali and H. halys. Contact toxicity of dinotefuran WP was excellent on P. stali but the others had low effect. While all insecticides except flonicamid, residual toxicity were all effective on P. stali. Dinotefuran have a excellent contact toxicity and chlorpyrifos and bifenthrin have good residual toxicity against both male and female of H. halys.
        28.
        2014.04 구독 인증기관·개인회원 무료
        Prior to 1990s, most farmers customarily sprayed the agrochemicals that only just recommended by association or pesticide dealers, regardless of the monitoring for the disease incidences and pest occurrences. In 1993, agrochemicals sprayed in apple orchards a year had been done about 15 ~16 times. As founded the Apple Research Station (ARS) in 1991, a study for the construction of Integrated Pest Managements (IPMs) were actively done during 1990s and the IPM was paved the way to control on apple diseases and pests during the 2000s. The co-work between ARS and Seoul National University during 1996 to 2001 for the monitoring and development of IPM strategies using sex pheromone made easy understanding for IPM and occurrence monitoring results by showing the pests to apple farmers. Through the 2000s, IPM pilot project for the distribution of IPM technique utilizing sex pheromone trap and mating disrupter to the field has endeavored. Currently, sex pheromone trap plays an important role for monitoring of the major apple pests and the quarantine pest, C. sasakii on apple. Moreover, sex pheromonebased mating disruptor has been used almost all organic apple orchards for the control of one of major fruit-infesting pest, G. molesta and C. sasakii. Henceforth, the application of sex pheromone trap for monitoring as well as the active expansion and provision of mating disruptor for the control is needed. To this, first of all, it is very important to reduce prices by developing the techniques than other things. Second, reinforced education for monitoring staffs must be done continuously to instruct and to consult the farmers with the monitoring results to give guidance. Third, companies competing in good faith will improve and maintain their product quality.
        29.
        2013.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 부패미생물의 종류와 차이를 알아보기 위해 유기농산물과 일반농산물(깻잎, 양배추, 상추)을 구입하여 4oC에 14일 저장한 후 일반목적배지를 사용하여 미생물을 분리 및 16S rRNA sequencing방법을 이용하여 동정하였다. 유기농산물 깻잎, 양배추, 상추의 총균수는 5-7 log10 CFU/g 수준이었고, 일반농산물의 총균수는 5-8 log10 CFU/ g 수준이었다. 유기농산물보다는 일반농산물이 총균수를 더 많이 내재하고 있으나 유의적인 차이는 나타나지 않았 다(p > 0.05). 유기농산물 깻잎에서 발견된 주요 균은 Microbacterium sp.이었으며, 일반농산물 깻잎에서 발견된 주요 균은 Stenotrophomonas maltophilia이었다. 또한, 유기농산물에서 부패를 일으킬 수 있는 균인 Klebsiella pneumonia 가 발견되었으며, 일반농산물보다 유기농산물에서 발견된 균의 종류가 더 많은 것을 확인할 수 있었다. 이에 본 연구 결과는 부패미생물에 대한 이해를 높이고 농산물의 신선도 및 유통기한을 늘리기 위한 새로운 살균소독제 및 부패 억제제를 개발하는데 좋은 기초자료로 사용될 수 있을 것으로 사료된다.
        4,000원
        30.
        2013.10 구독 인증기관·개인회원 무료
        Woolly apple aphid, Eriosoma lanigerum, one of the pests occurring in apple do damages on the branch and bastard slip nearby ground roots by sucking sap. Recently, seasonal population of this pest steadily increased but has scarcity the basic data relating to its ecology. This study was conducted to investigate the infested orchard ratio, environmental analysis of occurred orchard, seasonal population and parasite rate by Aphelinus mali, a natural enemy for woolly apple aphid, from 30 to 34 apple orchards, at 11 to 13 major apple producing areas in Gyeongsang-namdo and Gyeongsang-bukdo, Geolla-bukdo, and Chungchung-bukdo, during 2012 to 2013. It showed infested orchard ratio as about 35% and population density started to increase from mid-May, with its optimal density in late-June and increased again in late-September. This pest found in various rootstocks where infested orchards and could not found any significant pattern. The damage appeared in 9 to 35 year-old trees, severed rather old trees than younger trees. Also, orchards that did not eliminate bastard slip were showed high occurrence pattern. Parasite rates of Aphelinus mali showed the difference among investigated orchards but the rates showed generally increased pattern since early- July.
        31.
        2012.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study evaluated the quality characteristics of rice-doenjang prepared with Aspergillus oryzae MD05 and Bacillus subtilis HJ18-4. The physicochemical characteristics of rice-doenjang prepared with three types of meju, such as grain type(Rice 1), disc shape(Rice 2), and brick shape(Rice 3), were compared. We determined amino and ammonia nitrogen contents, protease and amylase activities, reducing sugar content, and total aerobic counts and lactic acid bacteria counts. The amino nitrogen and reducing sugar contents in all meju types gradually increased during fermentation. The amino nitrogen contents reached 151.5~200.0 ㎎%. Rice 3 were had the highest levels among the 4 types of rice-doenjang. After 42 days of fermentation, amylase and protease activity of Rice 3 were 366.57 and 94.26 unit/g, respectively, which were the highest levels among the 4 types of rice-doenjang. The total aerobic bacteria counts were not changed during 42-day fermentation. This results suggest that high quality characteristics of brick-shaped meju(Rice 3) were better than those of the other meju preparations.
        4,000원
        32.
        2011.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Myopalladin (MYPN) is an important expression gene associated with regulation of Z-line structure in muscle and maintains sarcomeric integrity. In this study, we investigated the association between MYPN A1795G SNP (single nucleotide polymorphism) and carcass traits (LMA, longissimus muscle area; CW, carcass weight; BF, backfat thickness; MS, marbling score) in Korean cattle. The MYPN A1795G SNP was genotyped in 212 steers and analyzed the associations with carcass traits by PCR-RFLP (Restriction fragment length polymorphism) method. The allele frequencies were 0.566 for G allele and 0.434 for A allele. And the genotype frequencies of GG, GA, and AA genotype were 32.1%, 49%, and 18.9%, respectively. Association analysis indicated that the A1795G SNP of MYPN gene showed a significant association with LMA (p<0.05). The steers with GG genotype had higher LMA than those with the genotypes AA. But no significant associations were observed in other carcass traits (CW, BF, MS). The steers with the GG genotype showed higher CW and BF than those with the genotypes AA and GA. These results suggest that the A1795G SNP of the MYPN gene is associated with LMA and may be useful for candidate marker-assisted selection to increase the levels of LMA in Korean cattle.
        4,000원
        33.
        2010.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        There are four (yellow, brindle, black, black in Jeju) kinds of native cattle in Korea. But only twelve hundred Korean brindle cattle (KBC) are remaining in limited areas of Korea and the genetic lineage, diversity, polymorphisms of KBC has not been identified. To analysis genetic polymorphism of KBC, 33 KBC were characterized using 11 microsatellite markers. Size of microsatellite marker was decided using Gene Mapper software after analysis ABI 3130XL. The average of allele numbers of KBC was 6.7 in this study, but that of Hanwoo was 10.0 in our previous report. The observed and expected heterozygosities of KBC were 0.719 and 0.738 but those of Hanwoo were 0.751 and 0.760 in our previous report. Also polymorphism information content (PIC) values were average 0.690 in KBC but 0.725 in Hanwoo. These results demonstrate that genetic polymorphism of KBC have decreased because the population was limited.
        4,000원
        34.
        2009.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A comparative analysis of the hindered amine light stabilizers (HALS) and UV abosrber (UVA) and their respective photostabilizing effect on wood plastic composites (WPCs) are reported in this study. The influence of accelerated weathering on the mechanical properties of the composites and the microscopic morphology of a degraded layer on the cross section and the surface were studied. UV absorbers were more efficient at preventing composite lightening than was UV stabilizer. The amount of whitening decreased with the increase of photostabilizers. With the addition of a UV absorber (Tinuvin360), the tensile modulus and strength of the composites increased slightly. However, the addition of a light stabilizer (Tinuvin770) and a UV absorber decreased the tensile modulus and strength of the composites. After 250 and 500 hr exposure, tensile modulus and strength of the un stabilized and stabilized composites decreased. The tensile strength of UV absorber (Chimassorb81)-stabilized composites was significantly greater than that of control and light stabilizer (Tinuvin770)- and UV absorber (Tinuvin360)-stabilized composites. UV absorber-stabilized samples showed less whitening and photodegradation than control and light stabilizer-stabilized samples.
        4,000원
        35.
        2009.06 구독 인증기관 무료, 개인회원 유료
        This study assessed the efficacy of aqueous chlorine dioxide (CIO2) and commercial chlorine sanitizer in terms of its ability to eliminate Listeria monocytogenes, Salmonella Typhimurium, and Escherichia coli 0157:H7 on radish sprouts (Raphanus sativus L.). Radish sprouts were inoculated with a cocktail containing one each of three strains of three different foodbome pathogens, then treated with distilled water (control) or chemical sanitizers (100 ppm commercial chlorine, and 50, 100, 200 ppm CIO2) for 1, 5, and 10 min at room temperature (22士2℃). Populations of S.Typhimurium, E. coli 0157:H7 and L. monocytogenes were counted at 4.64, 6.05, and 4.29 log CFU/g, respectively, after inoculation. Treatment with water did not significantly reduce the levels of any of the three foodbome pathogens. The levels of all three pathogens were reduced by treatment with chemical sanitizers; however, the observed 1evels of reduction of E. coli 0157:H7 and L. monocytogenes were not significant as compared with the controls. The levels of the three pathogens were reduced most profoundly when treated for 10 min with 200 ppm of CIO2, and the reduction levels of S. Typhimurium, E. coli 0157:H7, and L. monocytogenes were 1.17, l.63, and 0.9610g CFU/g, respectively. When chemically injured cells were investigated using SPRAB for E. coli 0157:H7 and by selective overlay methods for S. Typhimurium and L. monocytogenes, respectively, it was noted that commercial chlorine sanitizer generated more numbers of Í넌red pathogens than did CIO2. These data indicate that CIO2 treatment may prove useful in reducing the numbers of pathogenic bacteria in radish sprouts.
        4,000원
        36.
        2008.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Cellulose nanofibers from microfibril cellulose (MFC) was prepared by hydrobromic acid (HBr) treatment at different concentrations. Polyvinyl alcohol (PVA) composite films at various loading level of nanofibers were manufactured by a film casting method. The analysis of degree of polymerization (DP), crystallinity (Xc) and molecular weight (Mw) of cellulose after acid treatment was conducted. The mechanical and thermal properties of the cellulose nanofibers reinforced PVA films were characterized using tensile tests and thermogravimetric analysis (TGA). The DP and Mw of MFC by HBr hydrolysis considerably decreased, but Xc showed no significant change. After acid hydrolysis, the diameter of cellulose nanofibers was in the range of 100 to 200 nm. The thermal stability of the films was steadily improved with the increase of nanofiber loading. There was a significant increase in the tensile strength of PVA composite films with the increase in MFC loading. Finally, 5 wt.% nanofiber loading exhibited the highest tensile strength and thermal stability of PVA composite films.
        4,000원
        37.
        2008.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Nanocomposites with polypropylene/clay/wood flour were prepared by melt blending and injection molding. Thermal, mechanical and morphological properties were characterized. The addition of ballmilled clay, compatibilizer and wood flour significantly improved the thermal stability of the hybrids. The tensile modulus and strength of most hybrids was highly increased with the increased loading of clay, maleated polypropylene (MAPP) and wood flour (WF), compared to the PP/WF hybrids. The tensile modulus and strength of most hybrids were highly increased with the increased loading of ballmilled clay, MAPP and wood flour, compared to the hybrids with PP/WF. The transmission electron microscopy (TEM) photomicrographs illustrated the intercalated and partially exfoliated structures of the hybrids with ballmilled clay, MAPP and wood flour.
        4,000원
        38.
        2008.06 구독 인증기관 무료, 개인회원 유료
        This study examined the effects of lactic acid spray, hot water spray, or their combined treatment, as well as the effects of acidified sodium chlorite (ASC), for the decontamination of Escherichia coli on beef carcass surfaces using a commercial intervention system. With this system, the effects of 2 or 4% lactic acid (v/v), hot water (89±1oC), or their combined treatment, were examined in terms of reducing inoculated E. coli. ASC (266 ppm), which was adjusted to pH 2.5 using acetic acid or citric acid, was applied using a hand-held spray system. When the beef carcasses were treated with 2 or 4% lactic acid for 10.4 s, less than 1 log reductions of inoculated E. coli were observed. A hot water spray treatment for 9.8 s resulted in a 2.1 log reduction of inoculated E. coli. However, when the hot water was followed with either 2 or 4% lactic acid, no difference in E. coli reduction was found between the hot water alone or the combined treatment with lactic acid. When ASC was adjusted to pH 2.5 with acetic acid and citric acid, 3.8 and 4.1 log reductions of E. coli were observed, respectively. Overall, the lactic acid spray treatment was least effective, and the ASC treatment was most effective, for the E. coli decontamination of beef carcasses. Therefore, these data suggest that ASC would be a more effective intervention against E. coli than most of the methods currently being used. However, more research is required to evaluate the effects of ASC on other organisms, as well as to identify application methods that will not affect meat quality.
        4,000원
        39.
        2007.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Polypropylene (PP) composites with wood flour/wax/coupling agent were manufactured by melt compounding and injection molding. The influence of wood flour(WF), wax, and coupling agent on the mechanical and thermal properties of the composites was investigated. The addition of wood flour to neat PP has the higher tensile modulus and strength compared with neat PP. The presence of wax also improved the tensile modulus. At the same loading of PP and WF, the addition of coupling agent highly decreased the tensile modulus, and increased the tensile strength. From thermogravimetric analysis (TGA), the addition of wax improved the thermal stability of the composites in the later stages of degradation. The presence of MAPP and wood flour in turn decreased thermal stabilities of composites. From differential scanning calorimetry analysis (DSC), neither the loading of wax. nor the presence of MAPP has shown significant effect on the thermal transition of composites.
        4,200원
        40.
        2017.12 KCI 등재 서비스 종료(열람 제한)
        원자로 내 사고발생 시 냉각수의 비등으로 기포가 발생하고, 기포율을 측정하기 위하여 열수력 안전 분 야에서는 주로 Optical Fiber Probe(OFP)나 광학 카메라를 이용하여 측정하지만 기하학적 구조의 한계로 인 해 17 × 17 배열의 봉 다발 내에 장비를 설치하는 것에는 어려움이 있다. 본 연구는 예비 연구로서 봉 다발 에 적용하기 전 X선 시스템과 다양한 모사 팬텀을 이용하여 연구 가능성 평가를 수행하였다. 라디오그라피 및 토모그라피 실험을 통해 X선 발생 장치의 관전압 130 kVp, 관전류 1 mA가 적합하였다. 또한, 기포 해상 도 팬텀을 통해 가시적으로 1 mm 크기의 구멍에 대해 측정이 가능하였으며 막대 팬텀을 이용한 대조도 평 가의 경우 프레온 내부에서 대조도가 상대적으로 떨어짐을 확인할 수 있었다. 그러나 영상 재구성 시 일그 러짐이 없는 좋은 영상을 획득할 수 있었다. 기포 발생 팬텀 실험을 통해 기포의 유동 방향 확인 및 단층 영상을 획득할 수 있었고, Image J 툴을 이용하여 하나의 단층영상에 대해 18 %의 기포율을 측정할 수 있 었다. 본 연구는 핵연료 주변 기포율 측정을 위한 선행 연구를 수행하였고 지속적인 연구를 위한 기초 연 구로서 활용할 수 있을 것이다.
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