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        검색결과 416

        141.
        2013.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of the study was to investigate an effect of water temperature on a non-specific immune response and mortality of tilapia, Oreochromis niloticus, following a bacterial infection. Seventy five tilapia acclimated to 25℃ were then transferred at 16 and 36℃, and examined for non-specific immune responses over 12-96 h. Respiratory burst activity was reduced significantly in the group of fish cultured at 16 and 36℃ over 24-96 h, whereas phagocytic activity decreased significantly in the group of fish reared at a low temperature (16℃) over 12 and 24 h and high temperatures (36℃) over 12-96 h. Lysozyme activity diminished significantly in the group of fish transferred to 16℃ over 12-48 h, but increased significantly in the group of fish at 36℃ over 48 and 96 h. Alternative complement pathway (ACH50) decreased significantly when transferred to 16℃ after 12 h, but increased significantly when transferred to 36℃ after 24 h. In a challenging test, 30 tilapia reared at 25℃ were injected intraperitoneally with Streptococcus iniae at a dose of 2x107 cfu/fish, and then reared onward at water temperatures of 15, 25 (control), and 36℃. Over 12-96 h, the cumulative mortality of S. iniae-injected fish held in 16 and 36℃ was significantly higher than that of injected-fish held in 25℃ In conclusion, transfer of tilapia from 25℃ to low temperature (16℃) after 12 h, and transfer of fish from 25℃ to high temperature (35℃) reduced their immune capability. Furthermore, tilapia under temperature stress at 16 and 36℃ from 25℃ decreased its resistance against S. iniae
        4,000원
        142.
        2013.09 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The electrical and optical properties of fluorine-doped tin oxide films grown on polyethylene terephthalate film witha hardness of 3 using electron cyclotron resonance plasma with linear microwave of 2.45GHz of high ionization energy wereinvestigated. Fluorine-doped tin oxide films with a magnetic field of 875 Gauss and the highest resistance uniformity wereobtained. In particular, the magnetic field could be controlled by varying the distribution in electron cyclotron depositionpositions. The films were deposited at various gas flow rates of hydrogen and carrier gas of an organometallic source. Thesurface morphology, electrical resistivity, transmittance, and color in the visible range of the deposited film were examined usingSEM, a four-point probe instrument, and a spectrophotometer. The electromagnetic field for electron cyclotron resonancecondition was uniformly formed in at a position 16cm from the center along the Z-axis. The plasma spatial distribution ofmagnetic current on the roll substrate surface in the film was considerably affected by the electron cyclotron systems. Therelative resistance uniformity of electrical properties was obtained in film prepared with a magnetic field in the current rangeof 180~200A. SEM images showing the surface morphologies of a film deposited on PET with a width of 50cm revealedthat the grains were uniformly distributed with sizes in the range of 2~7nm. In our experimental range, the electrical resistivityof film was able to observe from 1.0×10−2 to 1.0×10−1Ωcm where optical transmittance at 550nm was 87~89%. Theseproperties were depended on the flow rate of the gas, hydrogen and carrier gas of the organometallic source, respectively.
        4,000원
        143.
        2013.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In order to improve the selective oxidation reaction of gaseous ammonia at a low temperature, various types of metal-impregnated activated alumina were prepared, and also physical and chemical properties of the conversion of ammonia were determined. Both types of metal (Cu, Ag) impregnated activated alumina show high conversion rate of ammonia at high temperature (over 300℃). However, at lower temperature (200 ℃), Ag-impregnated catalyst shows the highest conversion rate (93%). In addition, the effects of lattice oxygen of the developed catalyst was studied. Ce-impregnated catalyst showed higher conversion rate than commercial alumina, but also showed lower conversion rate than Ag-impregnated sample. Moreover, 5 vol.% of Ag activation under hydrogen shows the highest conversion rate result. Finally, through high conversion at low temperature, it was considered that the production of NO and NO2, toxic by-products, were effectively inhibited.
        4,000원
        144.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Rubber laminated bearings with lead core are highly affected by changes in temperature because key materials which are rubber and lead have temperature dependencies. In this study, two full scale LRB(D800, S=5) are manufactured and temperature dependency tests on shear properties are accomplished. The shear properties at the 3rd cycle are used at -10℃, 0℃, 10℃,20℃, 30℃, 40℃ respectively. The double shear configuration, simultaneously testing two pieces, is applied for compression shear test in order to minimize the friction effects due to the test machine, described in ISO 22762-1:2010. Characteristic strength, post-yield stiffness, effective stiffness, equivalent damping ratio are estimated and presented coefficient due to the temperature changes.
        4,000원
        145.
        2012.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, an oxygen plasma treatment was used as a low temperature debinding method to form a conductive copper feature on a flexible substrate using a direct printing process. To demonstrate this concept, conductive copper patterns were formed on polyimide films using a copper nanoparticle-based paste with polymeric binders and dispersing agents and a screen printing method. Thermal and oxygen plasma treatments were utilized to remove the polymeric vehicle before a sintering of copper nanoparticles. The effect of the debinding methods on the phase, microstructure and electrical conductivity of the screen-printed patterns was systematically investigated by FE-SEM, TGA, XRD and four-point probe analysis. The patterns formed using oxygen plasma debinding showed the well-developed microstructure and the superior electrical conductivity compared with those of using thermal debinding.
        4,000원
        146.
        2012.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Two sorghum(Sorghum bicolor L. Moench cv. Hwanggeumchal-susu and Miryang 3) samples were milled using different milling methods, and their physicochemical properties were tested. Particle size was classified into five groups such as pin mill and low temperature-microparticulation(LTM; 10, 000, 20, 000, 30, 000, and 40, 000 rpm). The water absorption index (WAI), water solubility index(WSI), and a rapid Visco analyzer(RVA) were used to examine particle size distribution and color differences. Particle size of sorghum flour prepared using LTM was lower than that prepared using a pin mill. Particle size was further reduced by successive dry milling of the LTM flour. Lightness of colored pigments increased when particle size decreased. The WAI of Miryang 3 pin milling(M1) flour was the lowest after LTM, and WSI was higher in the order of M2, M3, M4, and M5. LTM sorghum flour had significantly higher pasting viscosity, as determined using a rapid Visco analyzer. LTM Miryang 3 sorghum flour(M2~M5) flour showed lower breakdown viscosity and higher final viscosity compared to those of M1 flour, resulting in an increased setback value.
        4,000원
        147.
        2012.09 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Various adhesive materials are used in flip chip packaging for electrical interconnection and structural reinforcement. In cases of COF(chip on film) packages, low temperature bonding adhesive is currently needed for the utilization of low thermal resistance substrate films, such as PEN(polyethylene naphthalate) and PET(polyethylene terephthalate). In this study, the effects of anhydride and dihydrazide hardeners on the low-temperature snap cure behavior of epoxy based non-conductive pastes(NCPs) were investigated to reduce flip chip bonding temperature. Dynamic DSC(differential scanning calorimetry) and isothermal DEA(dielectric analysis) results showed that the curing rate of MHHPA(hexahydro-4-methylphthalic anhydride) at 160˚C was faster than that of ADH(adipic dihydrazide) when considering the onset and peak curing temperatures. In a die shear test performed after flip chip bonding, however, ADH-containing formulations indicated faster trends in reaching saturated bond strength values due to the post curing effect. More enhanced HAST(highly accelerated stress test) reliability could be achieved in an assembly having a higher initial bond strength and, thus, MHHPA is considered to be a more effective hardener than ADH for low temperature snap cure NCPs.
        4,000원
        151.
        2012.06 구독 인증기관 무료, 개인회원 유료
        Fresh oyster mushrooms (Pleurotus ostreatus) were gamma-irradiated at 0, 1, 2, and 3 kGy. The effects on various quality attributes were determined during storage at . Color changes were more prominent in the cap region than the stem part. At the start of storage increase of Hunter's L-value (lightness) was observed in the caps of 2 and 3 kGy-irradiated samples. The L-value was higher in the all irradiated samples during storage. The trend was different in the case of stem region, where L-value decreased upon irradiation, but remained high throughout storage. The -value declined, whereas the b-value increased following irradiation. Irradiation showed a dose-dependent effect on the firmness, which was clearer during storage, but the samples irradiated at 1 kGy maintained an overall better texture than other irradiated samples. The weight loss was also higher in the all irradiated samples during storage. The samples irradiated at 1 kGy showed good physical appearance without any fungal attack at the end of storage; however color change in cap region was quite apparent. The ultra-structural drastic effect of irradiation was understandable using scanning electron microscopy. E-nose analysis demonstrated a clear change in the volatile profiles of all irradiated samples. Although the effect of irradiation on quality characteristics was quite clear but the all irradiated samples were free from fungal attack that was observed in the case of control sample.
        4,000원
        152.
        2012.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 VOC 배출원 중 도장, 인쇄 공정에서 주요 발생물질인 톨루엔을 저온 분해할 수 있는 귀금속 팔라듐촉매 개발에 목적을 두고 있다. 팔라듐은 톨루엔 제거에서 활성이 우수하지만 비용이 높다. 따라서 실용성의 방안으로 Pd 담지량의 최소화 비율(0.1~1.0wt%)로 제조한 촉매의 활성을 측정하였다. 그 결과 1.0wt% Pd(R) 촉매가 모든 조건에서 가장 높은 활성을 나타내었다. 이는 SEM 촬영과 XRD 분석을 통해 촉매 제조과정에서 Pd의 담지량 및 소성 분위기에 따른 분산 형태와 연관이 있는 것으로 사료된다.
        4,000원
        153.
        2011.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 주요 봄배추 품종에 대하여 야간 저온처리가 생육 및 추대에 미치는 영향을 평가하여 봄배추 육묘 시 안정 환경관리의 기준을 설정하고자 수행하였다. 시험에는 '춘광' 등 주요 봄배추 7품종을 이용하였으며 생육상을 이용하여 야간에 5℃ 및 10℃의 저온처리를 실시하였다. 처리시점은 파종 후 5, 10 및 15일째부터, 처리기간은 각 처리시작 시점부터 5, 10 및 15일간으로 각각 조합 처리한 후 포장에서의 생육 및 추대 여부를 조사하였다. 시험에 사용한 모든 품종에 있어서 최대 5℃에서 15일간의 야간 저온처리에 의하여 유묘생육은 크게 저하하였으나 재배기간 동안 추대는 일어나지 않았으며 정식 90일 후 정상적인 수확이 가능하였다. '춘광' 품종에 대한 육묘기 야간 저온처리 개시 시점과 처리기간의 복합 처리 결과, 낮은 온도조건으로 어린식물체의 상태에서 처리기간이 길어짐에 따라 묘 생체중이 대조구에 비해 최대 59.3%까지 크게 감소되었다. 반면 저온처리 후 생육이 극도로 억제된 묘는 정식 후 생육이 다시 회복되어 수확시 생체중은 대조구 대비 72.3~110%의 범위를 나타내어 모든 처리구에서 정상적인 수확이 가능하였다. 또한 5℃ 또는 10℃에서 최대 15일간의 육묘기 야간저온 처리에 의한 추대 현상은 관찰되지 않았다. 본 연구를 통해 봄배추 주요 품종에 대한 육묘기 야간 저온이 생육에 미치는 영향은 제한적으로 나타났다. 육묘기간 동안 단기간 5℃ 이하의 저온에 노출된 경우에도 주간의 적정한 온도관리와 포장에서의 기후조건에 따라 추대를 지연시키거나 방지시킬 수 있을 것으로 생각된다.
        4,000원
        154.
        2011.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        지온상승억제 효과는 차광망(50%) +냉각수순환 평균 18.8oC(최고 23oC)가 가장 좋았으며, 차광망(50%) +지 하수순환 23.2oC(28.5oC), 차광도포제(30%)와 차광망 (50%)이 각각 24oC(최고 30oC) 순으로 나타났다. 고온기 근권냉각수 순환 효과가 가장 큰 모데나 품종은 절화장이 95.9 cm, 생체중이 67.0 g으로 가장 좋게 나타났다. 처리별 수량증가는 차광망(50%)처리에 비해 차광망(50%) +냉 각수순환이 121%로 가장 많았고, 차광망(50%) +지하수 순환, 차광도포제(30%)는 각각 59%와 65% 증가하였다. 하우스내부 야간온도를 8oC로 관리하였을 때 근권온수 순환이 평균 18oC 유지하여 무처리에 비해 약 8oC 정도 지온상승효과가 있는 것으로 나타났다. 동절기 지하부 온수순환처리에 의한 알스트로메리아 생육은 아스펜, 모데나, 샤넬 품종에서 절화장, 생체중 등 생육이 가장 좋았으며, 보르도 품종은 절화장이 다소 작게 나타났다. 근권온수 순환처리가 생육을 증가시킨 결과로 아스펜 등 4품종 모두에서 꽃목길이, 꽃목경경, 꽃수 및 꽃무게 등절화품질 또한 증가하였다. 생산량 또한 크게 증가하여 모데나 품종에서 38% 이상으로 가장 높았고, 아스펜, 보르도, 샤넬 순이었다.
        4,000원
        155.
        2011.10 구독 인증기관·개인회원 무료
        The occurrence and rapid range expansion of a fulgorid, Lycorma delicatula(White), has recently been reported in korea. It was previously known to occur in China, Japan, Vietnam and India. The first occurrence fo L. delicatula was reported in 2004 in the Cheonan. It has one generation per year and overwinters as egg masses on the bark of host trees. The number of egg per egg mass was 32.69±6.49. The cumulative ratio of hatchability at different temperature was the highest at 25℃ and the lowest at 10, 30℃. The egg hatchability was investigated in different regions in Chung-buk. Since L. delicatula eggs has been stored in -20±1, 0±1, 5±1℃ conditions for 1 ∼60 days, the cumulative ratio of hatchability was 2% stored in -20±1℃ for 3days, But hatchability was 52, 48% stored in 0±1℃ for 3, 14days and 82, 68% stored in 5±1℃ for 3, 14days. And hatchability was 0% for 60days. By straight regression equation(the growth ratio/treatment degree) the growth zero degree of L. delicatula was 10.4℃. The hatchability of L. delicatula in Cheongwon-gun, Okcheon-gun, Cheongju-city where’s winter lowest temperature was over -19℃ was over 79%. But The hatchability of L. delicatula in Jincheon-gun where’s winter lowest temperature was less than -19℃(continuos two days) was 35%.
        156.
        2011.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Alloys of nylon(PA6) and ethylene-propylene-diene polymer, modified with maleic anhydride(MEPDM) were prepared using a melt kneading process. This study focuses on the effects of the content of MEPDM in PA6 blend on the mechanical and thermal properties of such blends where MEPDM is the dispersed phase. Mechanical properties were examined by stress-strain measurements and impact strength test. Both impact strength of PA6/MEPDM at room temperature and at -20℃ were improved up to 400-550% with the amounts of MEPDM. However, PA6/MEPDM containing 3-5 wt% of MEPDM showed the about 700kgf/m2 of the maximum tensile strength but 8.5 % of the lowest elongation. For certain compositions of PA6 with rubbery MEPDM, the interesting reduction of elongation is caused by the reaction of the polyamide amine end groups with maleic anhydride portion in MEPDM, that provided a reinforcement in the PA6 matrix. In addition, the introduction of antistatic agent on the surface of alloys causes significant reduction of their surface electrostatic resistance.
        4,000원
        158.
        2011.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        일미찰과 흑진주찰의 예냉온도와 저온처리를 통한 풋옥수수의 품질 변이를 연구한 결과는 다음과 같다. 1. 예냉 처리 및 저장에 따른 품질변화에서 품종간 차이는 미비하였으며, 예냉처리 보다 저온저장이 외관 품질변화에는 더 큰 영향을 미침을 알 수 있었다. 2. 예냉처리 후 저장고 입고 초기까지의 이삭 품온 변화는 예냉처리구는 4시간, 냉장처리구는 입고 후 약 10시간 후 품온과 외기가 같아졌으며 저온처리구에서는 10일 까지도 포엽의 외관상 신선도가 유지되었다. 3. 상온처리구에서는 포엽이 마르면서 신선도도 떨어지고 중량도 감소하지만 고습으로 유지되는 저온처리구에서는 중량감소가 거의 일어나지 않았다. 4. 저장에 따른 식미관능평가에서 상온처리구에서는 저장기간이 길어질수록 식감이 떨어지지만 저온처리구는 오히려 수확직후의 옥수수보다 식감이 좋게 느껴질 정도로 부드럽고 씹는 맛이 좋았다.
        4,000원
        159.
        2011.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        직파품종 개발을 위한 특성검정으로 저온발아성을 조사하여 직파적응성에 알맞은 품종개발을 위한 기초자료로 활용하고자1994년부터 2008년까지 육성된 89개 품종을 이용하여 저온발아성을 검정한 결과 최근에 육성한 품종일수록 저온발아율이80% 이상으로 높았으며, 조생종이나 중생종보다는 중만생종의 저온발아율이 높은 경향이었으나 통계적인 유의차는 인정되지 않았다. 또한 최고품질이나 고품질 품종이 초다수성이나안전성 품종보다 저온발아율이 높았다. 품종이 육성된 기관별로 볼때는 직파품종 개발을 담당하고 있는 익산의 벼맥류부육성품종의 저온발아율이 다른 기관에서 육성된 품종보다 높게 조사되었다.
        4,000원
        160.
        2011.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        느타리버섯의 생육단계에서 재배온도 및 상대습도를 조절하여 선도 유지 기간을 연장하기 위해 수행한 결과, 생육온도별 저장기간에 따른 버섯의 수분함량은 상대습도가 낮은 처리에서 다소 낮았다. 생육조건별 중량감모율은 저장기간이 길수록 증가하였으며, 처리간 큰 차이 없었고, 갓신장율은 저온생육시에는 상대습도 95±5% 처리에서 저장 21일에 가장 높았으며, 대조구에서는 상대습도 80±5% 처리에서는 저장 24일에 가장 높았다. 버섯의 물성을 분석한 결과, 경도와 탄성은 저장기간이 길수록 낮아지는 경향이었으며, 상대습도 및 생육온도에 의한 차이는 거의 없었다. 따라서, 느타리버섯을 발이유기 후 생육온도 13℃, 상대습도 80%이상으로 조절하여 생육하여 250~300g 랩포장하여 4±1℃에 저장 했을때 24일까지 신선도를 유지할 수 있었다.
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