Withthe increasing trend of global trades and protection of agro-ecosystem in importing and exporting countries against quarantine pest, quarantine and pre-shipment(QPS) fumigation in perishable commodities is now more important to maintain postharvest quality until delivering to end user not just eradiation of quarantine pest. However, there are limited use of MB fumigation on export fruits and vegetables due to phytotoxic damages of fumigated one.
VapormateTM, alternative to methyl bromide(MB), a gas formulation of ethyl formate(EF) with carbon dioxide, is commercially in use for imported fruits fumigation such as bananas and lemon. Herein, based on previous preliminary studies, scale-up and commercial scale fumigation of ethyl formate is presented for promising export paprika and tomato. Efficacy of ethyl formate was described in terms of concentration × time (CT) products to Myzus persicae for paprika and Bemisia tabaci for tomato.
Since Montreal protocol in1989 designated MB(methyl bromide) as ozone depleting chemicals, IPPC(International Plant Protection Convention) has adopted replacing the MB with alternative chemical and reducing the rate of MB use in plant quarantine in 2008. Pineapples are one of the most frequently fumigated imported fruit with MB in Korea. However, there was no technically available replacement. Therefore, we evaluated phosphine(PH3) fumigation as alternative to MB in applying pineapples.
In the preliminary test, PH3 gas in 12L desicators to calculate ranged to 0.1 from 2g/m3 was tested at 2 and 24hr exposure to target pest, citrus mealy bug(CMB, Planococcus citri). All different of stage of CMB was shown 100% mortality when 2g/m3 of PH3 applied for 24hrs at 8℃. To confirm studies designed in 0.5m3 fumigation chamber, all egg, nymph and adult stages of CMB was killed completely and there wasn’t any phytotoxic and quality damages on pineapples for 2 weeks post-fumigation periods at 8℃. In terms of commercial use, further commercial research will need to be carry out in cooperation with importers and fumigators.
It is not easy to predict the shrinkage rate of a plastic injection mold in its design process. The shrinkage rate should be considered as one of the important performances to produce the reliable products. The shrinkage rate can be determined by using the CAE tools in the design produces. However, since the analysis can take minutes to hours, the high computational costs of performing the analysis limit their use in design optimization. Therefore this study was carried out to presume for mutual relation of analysis condition to get the optimum average shrinkage by regression analysis. The results shown that coefficient of determination of regression equation has a fine reliability over 87% and regression equation of average shrinkage is made by regression analysis
The triple eccentric butterfly valve has metal sheet and this study about butterfly valve ceiling is an innovative approach. But it is affected by the static pressure as well as cross-current. The damage at the valve on the pipe resulted from the reflux is due to valve leakage. This study is investigated on the triple eccentric disk and it is applied with angle and the static pressure in all cases to develop cross-current triple eccentric butterfly valves. The disc with the diameter of 300A is valve against flow velocity. The entrance pressure by flow characteristics is performed with numerical analysis. As the result, valve torque production is reduced more than the conventional triple eccentric valve and entrance pressure is decreased on the increase of valve open angle. And flow coefficient can be known to be increased.
Recently, the engineering designer of injection mold has become more and more dependent on the CAE. In the design factors of injection mold, the shrinkage rate should be considered as one of the important performances to produce the reliable products. Therefore, the shrinkage rate can be mostly calculated by the MoldFlow and CATIA in the design process. However, it is not easy to predict the shrinkage rate of a plastic injection mold in its design process because the analysis can take minutes to hours, the high computational costs of performing the analysis limit their use in design optimization. In this study, the surrogate models based on the Taguchi Design in order to optimize the shrinkage rate of bevel gear injection mold is used instead of the original models, facilitating design optimal design.
Predation, development, and ovipostion experiments were conducted to evaluate Amblyseius swirskii (Athias-Henriot) (Acari: Phytoseiidae) as a potential biological control agent for tomato russet mite, Aculops lycopersici (Massee) (Acari: Eriophyidae) which is a periodic pest of greenhouse tomatoes. Results show that A. swirskii attacked all developmental stages of A. lycopersici, and had a type II functional response on the prey densities given. The predation rates of A. swirskii on A. lycopersici in the presense of alternative food sources such as pollen, thrips first instar, or whitefly eggs were recorded as 74%, 56%, and 76%, respectively of the predation rate on A. lycopersici alone. Amblyseius swirskii successfully completed their life-cycle on either A. lycopersici or cattail pollen. At 25oC, 70% RH, development time of female A. swirskii fed on A. lycopersici or on cattail pollen took 5.0 and 6.2 days, respectively. For the first 10 days after moulting to the adult stage, A. swirskii fed on A. lycopersici had higher daily oviposition rate (2.0 eggs per day) than on pollen (1.5 eggs per day). From this laboratory study, it can be concluded that A. swirskii has promising traits as a predator against A. lycopersici and that their populations can be stably maintained using alternative food such as cattail pollen. We suggest that the effectiveness of A. swirskii against A. lycopersici under field conditions deserves to be investigated.