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        검색결과 72

        41.
        2018.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A study has been conducted on the structural analysis to reduce the light weight of the electric vehicle rotor shaft. ANSYS Static Structural was used for structural analysis. For weight reduction, the solid shaft was converted into a hollow shaft. The yield strength of the existing material SCM 440 is 655MPa, but to increase its safety, the yield strength is changed to 1,030MPa with SCM822H. At this time, weight reduction of about 47% was achieved. The resonance frequency of the rotor shaft was determined by vibration analysis and the structural safety was analyzed.
        4,000원
        42.
        2018.04 구독 인증기관·개인회원 무료
        The current protocols of methyl bromide (MeBr) fumigation on imported nursery plants, which are seriously infested with quarantine mealy bugs and scales, could be reevaluated because there were no limited uses of loading ratio, packing types etc. Another emerging issues is that the workplace health issues on MeBr fumigation are related with poor ventilation etc as well as well-known phytotoxic damages on them. In previous report, we have evaluated the efficacies of ethyl formate (EF) and phosphine (PH3) on different types of mealybugs. Herein, the phytotoxic damages of EF and PH3 on Alocasia, Sansevieria, Cactaceae and Croton genera were evaluated in terms of chlorophyll contents, color changes etc. This study showed that EF and PH3 fumigation on imported plants could be applicable to replacement of MeBr with further confirmation trials.
        43.
        2018.04 구독 인증기관·개인회원 무료
        Methyl bromide (MeBr) is well-known as a hazardous chemical to exposed fumigators and related workers as well as a ozone depletion chemical. According to recent report in USA and Korea, when MeBr fumigated on orange and grape at low temperature (<10℃), absorbed MeBr on fruits was slowly released to workplace. To replace MeBr practices urgently, ethyl formate (EF) fumigation is considered safer to worker (TLV of EF = 100 ppm compared to MeBr's = 1 ppm) and free from residual problem. We reports confirmative liquid EF (FumateTM) with N2 trials, which is cost-effective and non-CO2 gas emitted, on imported grapes. The 4hr-fumigation of 70 gm-3of EF (CTP > 114 gh-3) in scale-up chamber (10m3) fumigation (20% l.r.), showed efficacies to many kinds of insect pests, non-phytotoxic damage, providing safer guideline at workplace.
        44.
        2017.10 구독 인증기관·개인회원 무료
        Ethyl formate has been used for the control of insect pests by fumigation. However, there were not many reports toshow its target site of fumigant toxicity on insect pests since its first use in the agricultural industry. In the present study,we showed the presumable target sites of ethyl formate fumigation in insect pests using Myzus persicae nymphs. Afterethyl formate fumigation, the nymphs of this species were collected and the changes at the biochemical and molecularlevel were determined. The activity of cytochrome c oxidase (COX) was approximately two-fold higher after ethyl formatefumigation. In addition, the expression levels of acetylcholinesterase (AChE) decreased gradually with increasing ethylformate concentration. These two findings suggested that COX and AChE might be the major target sites of ethyl formatefumigation. In addition to these results, the analysis of lipid content using MALDI-TOF MS/MS identified 9 phospholipidsdifferently generated 2-fold higher in the ethyl formate-treated nymphs than that in the control nymphs, thereby leadingto changes in cell membrane composition in M. persicae nymphs. Therefore, the ethyl formate fumigation caused lethaleffects on M. persicae nymphs by changing COX activity, AChE gene expression, and phospholipid production.
        45.
        2017.10 구독 인증기관·개인회원 무료
        The spotted wing drosophila (SWD), Drosophila suzukii, is classified exotic quarantine pest in Australia and EU, soSWD-free must be supported by evidence of surveys and phytosanitary measures in exported host agricultural commoditiesin Korea. From a quarantine control point of view, SWD is importantly considered as model insect pest for exotic fruitflies (Bactrocera dorsalis) in Korea as well because of similarity in ecological cycles. In evaluations of ethyl formate(EF) only and combined cold treatment to kill eggs and larvae of SWD, the combined EF fumigation applied at LCt50%(50% killed lethal concentration X time) and cold treatement (5℃) for > 5 days showed the promise to new conceptfor eradicating quarantine pest and these could be helpful to pre-develop exotic fruit fly management in Korea.
        46.
        2017.04 구독 인증기관·개인회원 무료
        To replace methyl bromide (MeBr) due to its ozone depletion properties and the life-threatening to related worker as well as fumigators, ethyl formate (EF) fumigation on exported and imported fruits and vegetables has been developed by QIA in Korea since 2005. The benefits of using ethyl formate (EF) fumigant is considered as the safest practice among the commercially available chemical alternatives. The issues was that the cylinderized EF with carbon doxide (CO2) is not enough to extend their applications in terms of fumigation cost. We have developed the cost-effective liquid EF applications with nitrogen gas and demonstrated in quarantine trials (10m3) on imported bananas. We showed the new 35 gm-3 of EF applications with inert gas (nitrogen), were completely control all stage of citrus mealybug (Planoccous citri) for 4hr fumigation at 13°C. These applications meet the quarantine guidelines and protocols in terms of efficacies to target pest and safety concern as well as satisfactions of consumers showing no damages to imported bananas. Extensively, this cost effective EF technology could be acceptable to other fruit and vegetable commodities to reduce the fumigation costs and green house gas (CO2).
        47.
        2017.04 구독 인증기관·개인회원 무료
        The resistance of maize weevil(Sitophilus zeamais), an important agricultural pest of stored grain, on aluminium phosphide fumigant(PH3) has been reported recently in Korea. Many researchers reported that ethyl formate(EF), a potential methyl bromide alternative fumigant, showed good efficacy on several grain pests. In this trial, based on CTP (concentration × time products), we evaluated efficacy of EF on phosphine resistant and susceptible maize weevil. Each of insect strains were collected in grain storehouses and examined the PH3 resistance according to FAO method (Busvine, 1980). L(Ct)90 of PH3 resistant and susceptible strain was 48.3 and 0.3 g h m-3, respectively. When treated with EF, L(Ct)90 of PH3 resistant and susceptible strain was 90.0 and 110.9 g h m-3, respectively. In the case of EF, there was no difference between resistant and sucsecptible strain compare with PH3. These results indicates that EF is a potential alternative for aluminium phosphide resistance management in grain storehouses.
        48.
        2016.10 구독 인증기관·개인회원 무료
        The bulb mite (BM), Rhizoglyphus echinopus, is hard to control in the harvested onion and garlic. Methyl bromide (MeBr) fumigation is the only option to eradicate BM at present. However, MeBr causes phytotoxic damage (index 3) to onion and garlic and highly toxic to fumigators. To replace MeBr, we evaluated ethyl formate (EF) and phosphine gas (PH3) to BM at 5℃ which is current practical fumigation temperature. The >140 g·h m-3 of EF for 24 h could completely control BM and this CT (concentration × time) product was slightly (index 1) phytotoxic to onion and garlic. Fumigation of 2 g PH3 required >120 h exposure to kill 100% of BM without any pyhtotoxic damage. Further researches are being planned to shorten the exposure time with synergistic effect between EF and PH3.
        49.
        2016.04 구독 인증기관·개인회원 무료
        Exportation of sweet persimmon has been grown up recently, but the growth was accumulated because of quarantine and shelf life issues. Herein, we've investigated the concurrent processing of ethyl formate (EtF), a MeBr alternative quarantine fumigant, and 1-methylcyclopropene (1-MCP), an anti-ethylene compound, on sweet persimmon and suggested proper fumigation methods. An important quarantine pest, Tetranychus urticae, was inoculated on sweet persimmon, and then 70 g m-3 of ethyl formate has been fumigated for 6 h before and after 1 ppm of 1-MCP treatment for 24 h at 5°C condition. These concurrent processing showed the promise that efficacy of EtF was enough to meet quarantine guideline and shelf life of fruits was extended in terms of the hardness, surface color and sugar contents when treated fruits were stored for four weeks at 5°C.
        50.
        2015.10 구독 인증기관·개인회원 무료
        Methyl bromide (MB) fumigation is still allowed to use in quarantine treatment on imported timbers and logs, even though IPPC(International Plant Protection Convention) was strongly recommended to reduce their use in case of existing alternatives. A newly developing MB alternative fumigant, ethanedinitrile (EDN), showed the potential in terms of better efficacy to various timber pests and penetration into the timber than MB. Herein, for suggestion of quarantine guideline in Korea, we had verified the efficacies under different temperature conditions(5, 5-15, >15℃) and monitored TLV(Threshold limited value) of EDN post-fumigation for worker safety. The 6 scheduled doses of EDN depending on types of timber pest and temperature conditions had evaluated with PVC-Tarp tent(>100m3) with 40-50% loading factors of imported logs. To control normal wood related pests such as Japanese termite (Reticulitermes speratus) and bark beetle(Cryphalus fulvus), the scheduled doses 30, 40 and 40 g/m3 for 24hr fumigations showed >99% efficacy at 5, 5-15 and >15℃, respectively. The scheduled doses 100, 120 and 150 g/m3 for 24hr fumigations was also successful to gain the proved efficacies at 5, 5-15, >15℃, respectively, for the quarantine guideline to notorious wood related pests such as Japanese pine sawyer (Monochamus alternatus) and pine wilt nematode (Bursaphelenchus xylophilus). The recommended ventilation times with atmospheric conditions at ports was > 1 and > 2 hr under the fully uncovered and partially uncovered of fumigation tent conditions, respectively.
        51.
        2015.10 구독 인증기관·개인회원 무료
        Many forest pests present a problem during wood quarantine. The effectiveness of phosphine (PH3), which is an altered form of MB, was examined in Monochamus saltuaris and M. alternatus. After 24 h, the larvae and the adults of both insects were susceptible to PH3 at 3 mg/L at 20°C. However, the larvae of both pests were rather than dead, seem to have been quiescent condition. PH3 showed increasing insecticidal activity in a time-dependent manner in the larva stage of both pests. We investigated the fumigants at all stages of M. saltuaris and M. alternatus, as well as the synergistic effects of PH3 in controlled atmospheres of 50% and 80% oxygen. The atmospheric oxidation of PH3 fumigation slightly increased the toxicity of the fumigant to larva stages in 125 L container at 4 mg/L. These results indicate that highly concentrated atmospheric oxidation of PH3 could be useful as a fumigant agent against M. saltuaris and M. alternatus.
        52.
        2015.05 구독 인증기관·개인회원 무료
        분리막 생물반응기(MBR)는 전통적인 수처리 방법과 비교하여 안정적인 수질확보, 처리부지 감소, 높은 유기물 제거 등의 장점으로 인하여 매우 널리 사용되고 있다. 그러나 긴 고형물 체류시간과 높은 미생물 농도로 인하여 종종 인제거에 제한이 있다. 전통적으로 인을 제거하기 위해 화학적 침전 방법이 가장 널리 사용되고 있으나 이는 과량의 응집제 주입으로 인한 비용 문제 및 대량의 슬러지 발생의 한계점을 가지고 있다. 반면 흡착공정은 상대적으로 운전이 쉽고 간단하며 슬러지 발생량을 현저히 줄일 수 있는 방법이다. 따라서 본 연구에서는 입상 금속산화물 흡착제를 개발하고 이를 이용하여 MBR처리수 내의 인을 제거하는데 적용하고 성능을 평가하였다. 본 연구는 환경부의 연구비(과제번호 2013001390002)를 지원받아 진행되었습니다.
        53.
        2015.04 구독 인증기관·개인회원 무료
        The German cockroach, Blatella germanica, is one of the most important household pest that can cause disease on human. Conventional contact insecticides show less efficacy because it is hard to be contacted or digested by cockroach that lives inside small crevice. Ethyl formate(EF), which is a potential fumigant to control various insect pests such as stored grain insects and quarantine pests, can be penetrated wherever air exist and shows toxicity on respiratory system of insect. In this trials, we've demonstrated practical and commercial scale fumigations of EF on German cockroach. Efficacy of EF was described in terms of concentration × time (CT) product. At practical fumigation, EF gave 100% control of German cockroach nymph and adult when the CT product was 43.2g h m-3. When 600m3 scale warehouse fumigation for 15 hours with 5g m-3 of EF, nymph and adult stage of German cockroach were completely controlled. The ventilation time to reduce EF concentration under TLV(Threshold Limit Value, EF=100ppm) was less than 1 hour. These results show that EF can be applied at warehouse or mill house to control German cockroach effectively.
        54.
        2015.04 구독 인증기관·개인회원 무료
        With the increasing trend of global trades and protection of agro-ecosystem in importing and exporting countries, quarantine and pre-shipment(QPS) fumigation for perishable commodities are critical in terms of quality maintenance of fumigated commodities as well as eradicating quarantine pest. There are limited use of methyl bromide(MB) fumigation on fruits and vegetables due to not only worker safety issue at low temperature condition but phytotoxic damage to valuable commodities. We are here presented that commercial development of methyl bromide (MB) alternatives such as ethyl formate and phosphine gas formulated with carbon dioxide, that are increasing consumer and worker safety and avoiding phytotoxic damage in routine MB fumigation.
        55.
        2014.10 구독 인증기관·개인회원 무료
        Methyl Bromide (MB) has been regulated by montreal protocol due to ozone depletion since 1992, and there is a need to develop MB alternative fumigation methods. To find out the efficacies and tolerance in developmental stages of citrus mealybugs (Planococcus citri) which frequently infested in imported pineapples, phosphine(PH3) gas was tested in different exposure times (2~24 hr) and concentrations (0.1∼2g/m3) in small desiccators at 8℃. Based on Lethal 99% concentration × time products (LCTP 99%) of PH3 gas to target developmental insect, 2g/m3 PH3 was applied for 24 hr in 300 m3 fumigation facility, which was designed in well sealed and evacuation system (5 air exchange/min). We monitored PH3 gas in fumigation facility to confirm CTP and checked PH3 gas in atmospheres in air ventiliation process after fumigations to make quarantine guideline and protocol for worker safety as well as efficacy to target pest.
        56.
        2014.10 구독 인증기관·개인회원 무료
        Methyl bromide(MB) is a fumigant for quarantine and pre-shipment(QPS) that can eradicate target pests within short fumigation periods. However, MB, an ozone-depleting substance, is scheduled to be phased out in the second decade of this century. In contrast to MB alternatives for soil fumigation, there is no ideal alternative fumigant to MB for QPS of perishable commodities. It is important that all target insect pests are killed within a short fumigation time. The citrus mealybug(Planococcuscitri), a problematicquarantine pest from Korea, was exposed to ethyl formate and phosphine for different times and to different concentrations of EF(0.0∼33.4 mg/L) and PH3(0.25∼1.0 mg/L) in small desiccators. The eggs showed more tolerance than the nymphs and adults. To control the eggs, they were treated with a mixture of EF and PH3 for 2 and 4-hr. The egg stage showed 100% mortality with EF:PH3(25.1:0.25, 16.7:0.5, and 16.7:1.0 mg/L) at 4-hr. Treatment with a mixture of EF and PH3 for 4-hr at 8°C can control all stages of the citrus mealybug.
        57.
        2014.10 구독 인증기관·개인회원 무료
        This study was done to evaluate the efficacy of Vapormate (ethyl formate 16.7 % + CO2) as an methyl bromide-alternative fumigant. Some insect pests and mites were found under calyx of sweet persimmon fruits, including grape-myrtle scale, two-spotted spider mite, Amblyseius eharai. Vapormate fumigation was equally toxic to miticide- susceptible and -resistant T. urticae showing 100 % mortality at higher concentration than 146.7 and 211.0 mg/L, respectively. In persimmon-filled desiccator, summer and overwintering types of T. urticae showed 100 % mortality at higher concentration than 163.7 and 265.8 mg/L, respectively. Sweet persimmon damage from vapormate fumigation was not shown by the days after treatment. Tolerance of each live stage of grape-myrtle scale was in descending order: egg < nymph < adult. EF 141.5 mg h L-1 for 6 h at 5 ℃ killed 100 % of the larvae of D. punctiferalis. The final scaled-up fumigation confirmed the efficacy of EF to target pests and non-phytotoxicity on persimmons. In conclusion, EF may become a MB alternative fumigant for sweet persimmon, and the LC99 values of EF may be used to practical applications to all kinds of insects and mites on harvested sweet persimmon.
        58.
        2014.04 구독 인증기관·개인회원 무료
        Aphids are common pests frequently found in imported and exported fruits and vegetables. Methyl bromide(MB), a Quarantine and Pre Shipment(QPS) fumigant, could offer eradication of aphids within short period. However, MB is limited in use because of poor gas evaporation at low temperature(<5℃) and there is phytotoxic effect or damage on quality in post-harvest vegetables and fruits even at >5℃. Two candidates of MB alternative, ethyl formate(EF) and phosphine(PH3), are used and being investig at edonvarious fruits and vegetables fumigation to replace MB. Aphids are known as quarantine pest that are hard to control when conduct short period fumigation with PH3 and low dosage of EF. In this paper, dose response assessment of EF and PH3 are presented for three different aphid pecies : cotton aphid(Aphisgossypii), green peach aphid(Myzuspersicae) and turnip aphid (Lipaphiserysimi). The LCt99% values of EF at room temp. and low temp. (5℃) were 4.42 and 4.45 g·h·m-3 for cotton aphid, 3.23 and 5.58 g·h·m-3 for turnip aphid, 3.23 and 5.58 g·h·m-3 for green peach aphid when 2-hours fumigation. PH3 showed 0% efficacy on all species when 2-hours fumigation.
        59.
        2014.04 구독 인증기관·개인회원 무료
        Methyl bromide (MB), as a fumigant for Quarantine and Pre-Shipment(QPS) could offer eradication of target pests within shorter fumigation period and without phytotoxicity. Therefore, unlike MB alternatives for soil fumigation, there is no ideally MB alternative fumigant for QPS purpose, particularly for perishable commodities. It is critically important that within shorter fumigation time requires killing all target insect pests and without effect of quality and deliver treated fruit and vegetables to the final consumer. The citrus mealybug(Planococcuscitri), problem quarantine pest, was tested with different exposure times(2 and 4-hours) and concentrations(EF(0-200 g/m3) and PH3(10-50 g/m3)) in small desiccators for mixture tests. On sensitivity test with small desiccator, the egg stage showed 100% mortality with 200/25(EF/PH3) g/m3 and the nymph and adult stage showed 100% mortality with 10/10(EF/PH3) g/m3 on 2h. Also, the egg stage showed 100% mortality with 150/25(EF/PH3) g/m3on 4h.
        60.
        2014.04 구독 인증기관·개인회원 무료
        The fumigant activity of phosphine (PH3) and ethyl formate (EF) was determined to all stage of Phthorimaea operculella (Zeller) under high oxygen concentration (50% and 80%). Oxygenated PH3 and EF were tested at two different temperatures (20°C and 4°C) during 7 days. Two oxygenated fumigants were treated with LC10, 30 and 50 values of single fumigant against each stage of P. operculella. At 10% inhibition of hatchability concentration value, inhibition of hatchability of P. operculella eggs was shown 20.3% and 9.2% with 50% and 80% oxygenated PH3 at 20°C at 1 day after treatment, respectively. The fumigant activity of oxygenated PH3 was increased at all stage of P. operculella except eggs both 20°C and 4°C. However, oxygenated EF was determined low fumigant efficacy to hatchability of eggs and emergence rate of pupae. The insecticidal activities of P. operculella larvae and adults were slightly increased mortality rather than single EF. In this result suggests that oxygenated phosphine is effective method for managing P. operculella. But, oxygenated EF is not effective.
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