We assessed the susceptibility of three fumigants on Phthorimaea operculella, which is an important pest of stored potato worldwide. 5 to 6 initial dosage of each fumigants were treated on every growth stages of P. operculella. Methyl bromide showed 100% mortality at CT 33.40mg h/ L on egg, CT 14.41mg h/L on late larvae, CT 31.89mg h/L on pupae and CT 16.01mg h/L on adult, respectively. The LCT50 of methyl bromide was 19.115mg h/L on egg, 3.934mg h/L on late larvae, 13.810mg h/L on pupae and 6.260mg h/L on adult, respectively. In case of phosphine, 98% mortality was achieved at CT 16.77mg h/L on egg, and 100% mortality was achieved at CT 16.58mg h/L on late larvae, CT 18.54mg h/L on pupae and CT 12.28mg h/L on adult, respectively. The LCT50 of phosphine was 1.457mg h/L on egg, 2.236mg h/L on late larvae, 1.282 mg h/L on pupae and 0.253mg h/L on adult, respectively. In case of ethyl formate, 100% mortality was achieved at CT 96.21mg h/L on egg, CT 101.30mg h/L on late larvae, CT 120.66mg h/L on pupae and CT 148.30mg h/L on adult, respectively. The LCT50 of ethyl formate was 23.730mg h/L on egg, 13.706 mg h/L on late larvae, 29.578mg h/L on pupae and 19.235mg h/L on adult, respectively.
The existing ethyl formate fumigant is carbon dioxide (CO2) mixed liquified gas in metal cylinder, but this product type costs a lot to manufacture, translate and maintain cylinder. To supplement these problems, we have developed a new ethyl formate fumigation technique with nitrogen (N2) carrier. We assessed the susceptibility of mealy bugs, the most frequently detected pests in imported banana, and phytotoxicity of banana fruits. Ethyl formate and nitrogen were concurrently treated on citrus mealybug, one of the most resistant mealybug to fumigant, and ethyl formate was treated with LC50 product of independent treatment dosage. Nitrogen was treated with 7 dosages from 79% to 95% concentration. Phytotoxicity of banana was assessed by treating EF 35 mg/L with N2 79% for 14 days, and color, sugar contents and loss of weight were measured. EF with N2 treatment showed more than 50% of mortality on every growth stages, and there was no significant difference between control and treatment banana fruits. These results indicate that concurrent treatment of EF and N2 can be used to control mealybug in banana fruits.
The susceptibility of three fumigants, methyl bromide, ethyl formate and phosphine, and concurrent treatment of ethyl formate and phosphine were tested on Lasioderma serricorne. Susceptibility assessment were performed by treating 5 to 6 initial dosage on every growth stages of L. serricorne. The LCT50 of methyl bromide was 13.896mg h/L for egg, 36.038mg h/L for late larvae, 25.172mg h/L for pupae and 21.758mg h/ L for adult, respectively. The LCT50 of phosphine was 0.317mg h/L for egg, 0.649mg h/L for late larvae, 3.748mg h/L for pupae and 0.703mg h/L for adult, respectively. In case of ethyl formate, the LCT50 was 43.657mg h/L for egg, 137.606mg h/L for late larvae, 72.676mg h/L for pupae and 52.951mg h/L for adult, respectively. Concurrent treatment of ethyl formate and phosphine was performed by treating 5 to 6 initial dosage of ethyl formate with 0.5 mg/L phosphine for 4 hours on every growth stages of L. serricorne. The LCT50 of ethyl formate concurrent treatment was 13.746mg h/L for egg, 8.156mg h/L for late larvae, 27.087mg h/L for pupae and 11.353mg h/L for adult, respectively, and these results indicate that concurrent treatment can control pest with lower dosage and shorter period. Sorption rates and ventilation periods of each fumigants were also calculated for efficacy and safety
Recently, phosphine resistance of Sitophilus oryzae has been reported from China, India, Brazil and Australia. In this study, susceptibility of three fumigants were assesses on phosphine resistant and susceptible S. oryzae to investigate domestic phosphine resistance level and to use base data for resistance control. On susceptible insects, LCT50 of phosphine was 0.440mg h/L for egg, 0.602mg h/L for early larvae, 3.901mg h/L for late larvae, 6.171mg h/L for pupae and 0.295mg h/L for adult stage, respectively. LCT50 of methyl bromide was 9.997mg h/ L for egg, 12.113mg h/L for early larvae, 18.952mg h/L for late larvae, 21.104mg h/L for pupae and 17.824mg h/L for adult stage, respectively. LCT50 of ethyl formate was 75.795mg h/L for egg, 60.110mg h/L for early larvae, 160.491mg h/L for late larvae, 255.797mg h/L for pupae and 77.711mg h/L for adult stage, respectively. On resistant insects, LCT50 of phosphine was 6.959mg h/L for egg, 28.456mg h/L for early larvae, 48.170mg h/L for late larvae, 29.106mg h/L for pupae and 16.550mg h/L for adult stage, respectively. LCT50 product of methyl bromide was 17.842mg h/L for egg, 14.900mg h/L for early larvae, 25.840mg h/L for late larvae, 43.520mg h/L for pupae and 16.397mg h/ L for adult stage, respectively. LCT50 of ethyl formate was 60.034mg h/L for egg, 64.450mg h/L for early larvae, 149.028mg h/L for late larvae, 140.408mg h/L for pupae and 66.043mg h/L for adult stage, respectively. Domestic resistant S. oryzae showed 4 to 56 times higher resistance rate than susceptible insects.
Spotted wing drosophila, Drosophila suzukii, is an important pest of grape and strawberry because it lays egg inside fruit by damaging fruit surface. Recently, D. suzukii has been widely spreaded and causes several problems, so many countries include Australia designated D. suzukii as an important quarantine pest. Because of this, Korean farmers have trouble to export strawberry. In this study, we tested ethyl formate and phosphine to control D. suzukii, and also tested concurrent treatment of ethyl formate and phosphine to reduce phytotoxicity and enhance efficacy. When treated 35g/m3 of ethyl formate for 4 hours, mortality of egg, larvae, pupae and adult stages of D. suzukii was 22.2%, 21.1%, 19.2% and 28.3%, respectively. When treated 1g/m3 of phosphine for 24 hours, all stages of D. suzukii was completely controlled, but caused phytotoxic effect on strawberry. When treated with 35g/m3 of ethyl formate and 1g/m3 of phosphine concurrently for 4 hours, efficacy has been increased with less phytotoxicity than separate treatment. This result indicates that concurrent treatment enhanced efficacy with less phytotoxicity.
This research explored antecedents of stickiness of m-commerce sites, based on the push–pull–mooring (PPM) framework, which was developed to explain what leads people to move from one original location to another. In the current study, the stickiness of m-commerce sites was used as the opposite concept to switching. Therefore, pull effects refer to the positive factors which make consumers stick to an m-commerce site, while push effects refer to the negative factors which make consumers not stick with an m-commerce site. After reviewing the literature, responsiveness, ubiquity, enjoyment, and effectiveness were selected as the pull effects, while privacy concern and efficiency were selected as the push effects. The amount of money spent in specific mobile sites was considered as a mooring effect. According to the results of the structural equation modeling analysis, efficiency actually had a negative impact on stickiness of m-commerce sites. Also, a test of the mooring effect suggested that the negative impact of efficiency on stickiness of m-commerce sites was greater for people who spent more money in their mobile shopping compared to those who spent less. For both the high and low spending groups, responsiveness was the important pull effect as it was the strongest predictor of enjoyment for the low spending group and the strongest predictor of effectiveness for the high spending group (note that enjoyment and effectiveness had the strongest positive impacts on stickiness of m-commerce sites for the low and high spending groups, respectively.). Therefore, the fast response and feedback on m-commerce sites should increase consumers’ stickiness to these sites regardless of the amount consumers spend on these sites. On the other hand, the duration and retention of the low spending group of consumers were influenced by enjoyment the most.
E-WOM is described as all informal communications directed at consumers through Internet-based technology related to the usage or characteristics of particular goods and services, or their sellers (Litvin, Goldsmith and Pan, 2008). In contrast with conventional WOM, e-WOM has unique characteristics. For instance, it often occurs in strangers or fellow consumers, and can be and can be anonymous (Goldsmith & Horowitz 2006; Sen & Lerman 2007). In this regard, people feel free to express opinions without identity disclosure (Goldsmith & Horowitz 2006).
INTRODUCTION
In a word dominated by social media, the diffusion of e-WOM is undoubtedly speeding up. Plus the international trade prevailing, people can experience products from all over the world at home, and they typically collect both positive and negative e-WOM for domestic and foreign brands with the aim of comprehensively evaluating the brands and their products. It is worth mentioning that in reality consumers often adheres to consumer ethnocentrism (CE) to counter the significant effects of imports on domestic economies and defend against foreign products in local markets. So far, there has been relatively little research on the effect of e-WOM on CE. In our study, we employ social media to discover the impacts of e-WOM on CE with respect to domestic and foreign smart phone brands from the Chinese e-WOM receiver’s perspective. Simultaneously, we test consumer pride and prejudice toward mature industries in the home country. Drawing on survey data from 302 consumers, our study reveals several significant findings. First, positive e-WOM regarding local brands may enhance CE, whereas positive e-WOM regarding foreign brands may reduce CE. Second, Negative e-WOM may break the advantage of CE for domestic brand, which result in the dominance of foreign brand. Third, positive e-WOM may enhance brand equity for both domestic and foreign brands. By contrast, negative e-WOM has no significant influence on Chinese consumers’ attitude toward brand equity. Finally, CE has positive influence on brand equity for domestic brand but not effect on foreign brand. To our best of knowledge, our paper is the first to study the effect of e-WOM on CE, which enriches the relevant theory with regard to CE.
The proportion of collision in the total marine accidents is high. The main causes of collisions are navigation rule violation, safety speed violation, neglected watch-keeping and improper collision avoidance action. There are two main ways of avoiding collision situations during maritime navigation: the method of altering course and reducing ship’s speed. The purpose of this study is to analyze the result of the collision avoidance action of the reserve officer in case of encountering a multiple number of ships using the ship handling simulator. Full-mission ship handling simulator was used to experiment the situation scenarios that encountered multiple ships. After the experiment, the questionnaire about the experiment was investigated. A total of 50 subjects were participated in the experiment. Experimental results showed that the number of the experimenters who used the engine was 11 and the number of the experimenters who did not use the engine was 39. In the case of using the engine, there were 0 collision accident, 1 grounding accident, and 10 no accidents. However, when the engine was not used, there were 28 collision accidents, 2 grounding accidents, and 9 no accidents. The causes of these results can be found in the survey results. 74 % of the non used engine participants said they were hesitate to use the engine. As can be seen from these results, the reserve officer are hesitant to use the engine and need a way to get correct of it. Maritime course subject can emphasize the importance of using ship’s engines and case study also can be it. So, It is considered that various case study scenario will need to developed by various tools in the future.
Carbonyl sulfide is a chemical that is registered as a crop protection product in Australia due to microorganisms such as soil, plant roots, branches, fertilizers and compost. In order to develop new fumigants for domestic use, the susceptibility of Carbonyl sulfide fumigants to two agricultural pests was evaluated. The susceptibility of peach aphid and spotted mite, which is an agricultural pest, was evaluated. After 5 hours of treatment (10, 20, 40, 60, and 80 mg / L) . As a result, peach aphid larvae showed a high mortality rate of 97.6% at 10 mg / L and 100% at 20 mg / L or more. Larvae were found to have a rate of 95.8% at 80 mg / L. The insect mortality rate was 91.8% at 60 mg / L and 94.1% at 80 mg / L.
Mediterranean fruit fly, Ceratitis capitata, is one of the most important quarantine pest worldwide. Fruit flies cause serious damage on orchard, and also can cause quarantine problem to fruit exportation. Recently, because of global warming, there is threats of fruit fly invasion to Korea, especially to Jeju island. So there should be a anticipative research about fruit fly control. Many physical quarantine treatment methods, like heat treatment and low-temperature treatment, are developed to control quarantine pests. Recent researches indicate that low-temperature treatment shows good efficacy on several quarantine pests without phytotoxicity. In this trial, we’ve applied the low-temperature treatment on citrus at laboratory and pilot scale containers to validate efficacy and phytotoxicity. Egg and larvae stage of C. capitata was completely controlled after 5 days and 8 days low-temperature treatment at 0℃ respectively, and there was no phytotoxicity on citrus. These results indicate that the low-temperature treatment can be applied to control fruit fly on citrus fruit.
The susceptibility of the Cigarette beetle, which are pests in tobacco, to methyl bromide and phosphine fumigants was evaluated. Five concentrations of each methyl bromide were selected for all stages and treated for 4 hours. As a result, 100% larvae were observed in eggs CT 51.20, late larva CT 73.61, pupa CT 71.87 and adult 52.87 mg h / L, respectively. The LCT50 values for methyl bromide were 13.896 for eggs, 36.038 for late larvae, 25.172 and 21.758 mg / l, respectively. The phosphine treatment was carried out for 5 to 6 concentrations (0.025, 0.051, 0.099, 0.501, 0.999 and 1.500 mg / L) for 20 hours. As a result, egg and late larvae showed 100% larvae at CT 5.137 and 6.435 mg h / L, respectively, and 61.9% and 98.9% of larvae and adult larvae were similar to each other. Pupae showed 86.4% larvae at CT 10.520 and 100% larvae at over 13.777 mg / h of CT. The LCT50 values for phosphine were 0.317 for eggs, 0.649 for late larvae, 3.748 for pupa and 0.703 mg / l for adults.
Since methyl bromide(MB) has been designated as ozone deplete substance(ODS) by Montreal protocol (1989), many MBalternative fumigants like ethyl formate and phosphine gas were developed and commercialized. Ethyl formate(EF) is an effectiveMB alternative fumigant to control insect pests on imported fresh commodities. It is important to develop a proper evaporationmethod to apply EF on large scale fumigation because EF has a high boiling point(54℃). Recently, concurrent treatment ofethyl formate and nitrogen(EF+N2 treatment) has been newly developed. At preliminary test, EF+N2 treatment showed goodevaporation rate and showed high efficacy on quarantine pests without phytotoxicity on fresh commodities. In this trial, we’veapplied the EF+N2 treatment on imported orange and lemon at pilot scale (0.5m3, 10m3) containers and commercial scale containerto validate efficacy and phytotoxicity. 70g/m3 of EF liquid was applied on orange and lemon by EF+N2 treatment method,and showed 100% mortality on tested insect pest(Tetranychus urticae) without phytotoxicity at 0.5m3 and 10m3 scale fumigationtrials, respectively. At commercial scale trial, EF+N2 treatment also showed 100% efficacy on T. urticae and there was nophytotoxic symptoms on imported orange and lemon fruit. These results indicate that the newly developed EF+N2 treatmenthas a potential as a MB alternative, and can be applied on imported fresh commodities for quarantine and pre-shipment purpose.
This study evaluated the antimicrobial efficacy of different concentrations of ozonated water with organic matter, fetal bovine serum, at different concentrations and incubation times with bacteria. In the absence of organic matter, total eradication of up to 5 log of Escherichia (E.) coli was achieved, however, interference by organic matter led to inefficiency of ozonated water as a disinfecting agent. In addition, diminishing antimicrobial effects at higher temperatures, even in the absence of organic matter, were also demonstrated. These findings indicate that ozonated water will be a safe and effective disinfectant agent that could be useful in meat processing, especially an intestine processing, in Korean slaughter houses.