검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 535

        161.
        2018.11 구독 인증기관·개인회원 무료
        The early-onset familial Alzheimer's disease (EOFAD/ FAD), the less common type of Alzheimer's disease (AD) currently affects a vast number of individuals worldwide. This type is being inherited as an autosomal dominant fashion. Missense mutations on Amyloid precursor protein (APP) and Presenilins 1 and 2 (PSEN1 & PSEN2) are known as major genetic factors in FAD. Conversely, missense mutations on microtubule-associated protein tau (MAPT) are also thought to involve. Up to date, several triple-transgenic animal models with muted forms of the human APP, PSENs and MAPT have been reported. Compared to other animals, canines are more emotional and their disease signs can be easily diagnosed. This attempt was to develop a triple transgenic canine model for the AD. We have obtained the coding sequences of APP, PSEN1 and MAPT from Dana-Farber/Harvard Cancer Center DNA resource core at HMS and incorporated several common AD mutations. The transgenic construct is composed of hNSE (ENO2) promoter-driven three AD genes fused together with modified 2A sequences. It was transfected into the canine fetal fibroblasts which were then used to perform somatic cell nuclear transfer (SCNT). The viable transgenic embryos were obtained after in vitro culture and the GFP was detected. In this study, we have successfully produced viable triple transgenic canine cloned embryos using SCNT technique. These transgenic canine embryos will be further developed into canines with FAD. The transgenic canines will be a good candidate in the AD research field.
        162.
        2018.11 구독 인증기관·개인회원 무료
        To preserve the superior genetic resources and restore the endangered species, Somatic cell nuclear transfer (SCNT) has been used widely. In Korea, the research of dog cloning has made outstanding achievements including the production of the world`s first cloned dog. Sapsaree (Sapsalgae), the representative dog of Gyeongsan-si was designated as a Korea natural monument (No. 368). This male dog used in this study has azoospermia due to unknown cause. In this study, the aim was to confirm the cause of infertility in the cell donor dog and to evaluate the reproduction potential of dog cloning using infertile male dog by SCNT. First, to confirm the infertility of the cell donor dog, the reproductive history and the testis were evaluated. The breeding histology was not recorded in individual document. In histopathology, the Sertoli cell tumor was confirmed in biopsy of the cell donor dog after death. But, these tumors are predominantly in older dogs. Second, we produced the cloned dogs with the somatic cells of the infertile dog and the appearance was similar with the cell donor dog. Also, microsatellite analysis confirmed the genetic relationship between the cell donor and clone dogs. Third, the potential breeding capacity of the cloned dog was confirmed. In T4 assay, the normal dog (same age with cloned dogs), cell donor dog, and cloned dogs was investigated. The cell donor dog with azoospermia had very low T4 level, and cloned dogs showed higher level of T4 than normal dogs. In CASA, There was no significant difference in sperm motor ability between normal dogs and cloned dogs. As a result, cloned dogs produced by SCNT had no problem regarding the reproductive function of the testis. In AI experiment, the semen of clone dogs was used to fertilize a natural female bitch and was diagnosed pregnancy by ultrasonography. In total, 7 puppies were born by normal delivery (male: 3, female: 4). In conclusion, this study confirmed that the reproduction problem of non-genetic infertility can generate a normal descendant by SCNT. Also, the first successful research to restore infertile dogs was completed. Furthermore, SCNT would be useful for the restoration of endangered species and application of superior traits.
        165.
        2018.10 구독 인증기관·개인회원 무료
        Tomato yellow leaf curl virus (TYLCV) and its vector insect, the sweet potato whitefly Bemisia tabaci, are major threats to tomato and pepper production in all around world. Since the last three decades, both B. tabaci and TYLCV have been invaded into many countries via different routes. Our studies showed that various geminiviruses including TYLCV can be transmissible by seeds as well as whiteflies. Furthermore, commercially developed resistant tomato strains against TYLCV infection can serve as TYLCV reservoirs and potentially influence on TYLCV epidemics. Therefore, transmission pathways through both insect vectors and seeds should be concerned for suitable management of geminiviruses and whiteflies.
        166.
        2018.09 구독 인증기관 무료, 개인회원 유료
        With President Trump’s recent imposition of USD 34 billion in new tariffs on imports from China and China’s prompt retaliation, the US is now in its biggest trade war with China and other countries since the 1930s. President Trump’s policies focusing on threats, trade deficits and bilateral trade, as well as the movement away from the postwar international system, have been historical aberrations since 1945. The US trade diplomacy ought to concentrate on building coalitions and viable proposals for addressing trade issues, including those concerning the World Trade Organization rule-making and dispute resolution. This would help to ensure a rules-based trading system.
        4,300원
        167.
        2018.07 구독 인증기관 무료, 개인회원 유료
        Introduction The attributes of the Chief Executive Officer (CEO) have a significant influence on the actions of the organization and, ultimately, firm performance (Chatterjee & Hambrick, 2007; Kashmiri, Nicol, & Arora, 2017). Recently, there has been growing interest in one particular CEO attribute, i.e., narcissism and how this individual characteristic affects actions taken by the firm and the outcomes achieved. Narcissistic CEOs have been described as “having an inflated self-concept that is enacted through a desire for recognition and a high degree of self-reference when interacting with others (Resick, Whitman, Weingarden, & Hiller, 2009: pg. 1367).” Prior research has found that CEOs with a more narcissistic personality make riskier decisions by changing the company’s strategy more often (Chatterjee & Hambrick, 2007), making acquisitions more frequently and of larger targets (Chatterjee & Hambrick, 2007), adopting discontinuous technologies (Gerstner, König, Enders, & Hambrick, 2013), and expanding international business activities (Oesterle, Elosge, & Elosge, 2016). The results of previous studies show that by pursuing decisions with greater risk and involving the firm in wide-ranging efforts, the actions of narcissistic CEOs lead to fluctuating firm performance (Chatterjee & Hambrick, 2007) and diminishes the positive effect of various firm activities. While these prior studies have provided valuable insight, the strong emphasis on the organizational actions taken as a consequence of the narcissistic CEO has not added to our understanding of the relationship between CEOs who seek personal affirmation, admiration, and attention and important intervening variables for firm performance such as corporate brand reputation. Corporate brand reputation signals the status of an organization and influences the actions of capital markets, investors, consumers, and applicants in the job market (Fombrun & Shanley, 1990). Managers actively work to construct favourable corporate brand reputations through the actions the firm takes and the information selectively released to the media and public. Yet, the literature suggests that narcissistic CEOs spend time focusing on how to enhance their own image rather than on achieving organizational goals (Resick et al., 2009). In this regard, the attention-seeking CEO likely becomes a focal point for the corporate brand. However, no research to date has examined the relationship between the narcissistic CEO’s personality and the effects of corporate brand reputation. This study fills the gap in the literature by investigating how CEO narcissism influences the effectiveness of corporate brand reputation on firm performance. Theoretical development The literature on corporate brands noted that corporate brand reputation is a critical intangible asset that affects firm performance (Roberts & Dowling, 2002). Stakeholders use corporate brand reputation as a means to compare and contrast competitors Researchers have noted various advantages for highly reputable firms: customers are willing to pay more for offerings (Roberts & Dowling, 2002) and accept new product innovations (Dowling, 2002); managers accept lower remuneration (Tavassoli, Sorescu, & Chandy, 2014) and receive higher payoff for investments (Benjamin & Podolny, 1999). These types of advantages allow for greater performance. Thus, consistent with prior literature, we argue the following: Hypothesis 1: Corporate brand reputation has a positive effect on future firm performance. Research has shown that CEO narcissism diminishes the effect of the firm’s positive actions. Petrenko, Aime, Ridge, and Hill (2016) argue that narcissistic CEOs pursue Corporate Social Responsibility efforts (CSR) as a means to enhance their own image. Yet, the authors found that the narcissistic CEOs actually reduce the positive affect of CSR initiatives. Likewise, Engelen, Neumann, and Schmidt (2016) examined the effect CEO narcissism had on the relationship between entrepreneurial orientation and performance finding that CEO narcissism lessens the positive effect of entrepreneurial orientation. These results are due to the narcissistic CEOs perpetual need for attention and self-affirmation which leads to unconcentrated work initiatives and a lack of attention to the needs of employees. When subordinates’ needs are ignored they develop a sense of powerlessness, incompetence and a lack of desire to present their own ideas. This environment diminishes entrepreneurial engagement (Engelen et al., 2016; Wales, Patel, & Lumpkin, 2013). In line with this view, we believe the attention-seeking narcissistic CEO competes with the development of the corporate brand and will dampen the positive effect of highly reputable brands on firm performance. Thus, we argue the following: Hypothesis 2: CEO narcissism diminishes the positive effect of corporate brand reputation on firm performance. Method We compiled a unique unbalanced panel composed of data from COMPUSTAT, ExecuComp, and Fortune Most Admired Companies listing. Our sample includes 993 firm-year observations consists of 237 CEOs from 144 U.S companies on eight-year period, 2009-2016. Data on CEOs were collected from the ExecuComp databases. Financial performance data were from COMPUSTAT. Firm reputation was obtained from firm’s published score in the Fortune “Most Admired Companies” survey in a given year. The fortune rating is obtained through surveys from executives and directors, and has been widely used in previous research (Love, Lim, & Bednar 2017). Our independent and control variables are measured in the year prior to the one in which the survey ratings are published. CEO narcissism is invariant meaning narcissism is a relatively stable disposition similar to Chatterjee and Hambrick’s (2011) and obtained by averaging data from the second and third years of each CEO’s tenure (t + 1 and t + 2). First year of the CEO’s tenure was not considered because of frequently mentioned anomalies reported at first year. CEO narcissism was measured with the same way as Chatterjee and Hambrick’s (2011). Thus, it combines indicators for (1) the prominence of the CEO’s photograph in the company’s annual report; (2) the CEO’s prominence in the company’s press releases; (3) the CEO’s use of first-person singular pronouns in interviews; (4) the CEO’s cash relative pay where cash compensation divided by that of the second-highest paid executive in the firm; and (5) the CEO’s non-cash relative pay where non-cash compensation divided by that of the second-highest-paid executive in the firm. Dependent variables were measures annually and consider available data after the second-year tenure of CEO (n > 2), yielding a 380 firm-years, 61 CEOs for testing our hypothesis. Firm performance was measured with Tobin’s Q (TQ), calculated by dividing the firm’s market value by firm’s asset replacement costs. We have the CEO, the firm, and the industry level control variables. CEO level control variables are CEO age, CEO tenure, CEO gender, CEO stock ownership as the percentage of company stock owned by the CEO, whether the CEO was also board chairman (duality). Firm-level control variables are firm’s the prior year performance, firm size (natural logarithm of revenues t+n–1), firm age, for each dependent variable, to consider strategy or performance tendencies, we included performance value for the firm in the year prior to the start of the CEO’s tenure (t – 1). Industry control variables are dummies for the industry sector (manufacturing, regulated and services industries), the industry average (for all firms in the sample, always excluding the focal firm) in each year (t + n), for each dependent variable to be able to control for industry tendencies. To control for endogeneity i.e. narcissistic CEOs are drawn to certain situations and/or that some conditions, we followed exactly the same procedure of Chatterjee and Hambrick’s (2011). Thus, we regressed CEO narcissism on firm revenues, age, ROA, and calendar year for the year prior to the CEO’s start, ROA change between first and second years of CEO tenure, measures in t+1, namely power (CEO/chair duality and CEO ownership), CEO age, industry dummies. Using the regression coefficients of the significant variables, we calculated each CEO’s predicted narcissism score and included that value as an endogeneity control in our analyses. We used generalized estimating equations (GEE) (Liang & Zeger, 1986), which derive maximum likelihood estimates and accommodate non-independent observations. Due to multiple observations for almost all firms, there is non-independency in our model. We specified a Gaussian (normal) distribution with an identity link function. The covariance structure of the repeated measurement was autoregressive of order one (AR(1)). We used robust variance estimators in our estimations. We used the xtgee routine in Stata 14.2. Results and conclusions The results provide considerable support for hypotheses 1 and 2. Hypothesis 1 predicted that corporate reputation has a positive effect on firm performance (b = .02, p < .01). CEO narcissism is a moderating effect between corporate brand reputation and firm performance. Specifically, CEO narcissism diminishes the positive effect of corporate reputation on firm performance (b = -.04, p < .05). Besides, CEO narcissism have a negative main effect on firm performance (b = -.14, p < .05). Corporate reputation is an intangible asset for firms and positively associated with firm performance according to our results. Little is known so far about the CEO and corporate brand relationship and the role of CEO brands in creating value for the company (Bendisch, Larsen, & Trueman, 2013). We investigated how CEO narcissism influence the relationship between firm’s reputations and firm performance which have not been investigated so far. Since CEOs are the face of the company and it contributes to corporate brand value, narcissistic CEOs might diminish the effect of corporate brand reputation on firm performance with their actions and messages. We find support for our ideas. As a future research, we suggest investigating this issue for different industry sectors and different firm performance measures. Besides, the process of what type of actions of CEOs might diminish brand value should be investigated further. When narcissistic CEOs reduce corporate brand reputation, another potential topic worth to investigate further.
        4,000원
        168.
        2018.07 구독 인증기관·개인회원 무료
        Consumer arrogance is conceptualized and defined by Ruvio & Shoham (2016) as people's proclivity for demonstrating their social superiority through the acquisition, utilization, or display of consumer goods. This new notion rooted from the symbolic meaning of consumption that suggesting consumers use products as symbols to create self-identity, to maintain their self-concept, to express their self, to convey personal and social achievements and to reflect their social status to others (Holman, 1981; Belk, 1988; Hirschman & LaBarbera, 1990). This research examines the cross-cultural validity of the Ruvio & Shoham‘s (2016) consumer arrogance scale in Turkey and Romania. Data were collected from 192 Turkish and 176 Romanian students. Confirmatory factor analysis was used to test the four-factor solution. The scale demonstrates internal consistency and validity within the two countries and across countries. The cross-cultural validation tested via configural, metric and covariance methods. The results indicated that the consumer arrogance scale is consistent across countries and it can be established as a second order construct. The nomological validity with structural equation modelling results support that consumer arrogance is predicted by materialism in both countries. This cross-national study extended consumer arrogance scale in a collectivist cultural setting and contributes to enriching cross-cultural validation research as well as consumer behavior understanding.
        169.
        2018.07 구독 인증기관·개인회원 무료
        Social media have altered the communication landscape and significantly impacted brand communications in the luxury fashion industry. Research suggests that with the rise of social media, brand communication has been democratised, and the power has shifted from those in marketing to the individuals and communities that create and consume content, redistributing it across a variety of channels (Kozinets, Valck, Wojnicki, & Wilner, 2010; Kumar & Sundaram, 2012). Yet the implications of social media are still largely unknown among practitioners and managers. Moreover, there is a lack of effective frameworks for developing, analysing and comparing social-media strategies (Effing & Spil, 2016). Scholars have just started giving their attention to the subject of ‘social-media strategy’ as such, highlighting a gap in our knowledge, which this study seeks to address. The aim of this research is to understand the role of social media as a strategic brand-communications tool in the luxury fashion industry. Firstly, the main theoretical contribution is the development of a conceptual framework that enables an understanding, explanation and description of the process of building a social-media strategy. There has been a call for this type of research from a managerial perspective, across multiple platforms and objectives, and this work provides much-needed insights. Secondly, the findings provide valuable managerial insights. The conceptual framework emerging from this research is a managerial tool that can be used to tackle the process of building a social-media strategy and to identify its key elements. In particular, the framework can be deployed to guide and evaluate the process of creating a social-media strategy. With the help of the framework, managers can harness their resources successfully and identify the factors that need to be considered. Moreover, the framework aims to guide managerial action towards a sustainable social-media approach that helps to build competitive advantage for global luxury fashion brands in the longer term.
        170.
        2018.06 구독 인증기관 무료, 개인회원 유료
        Physical smothering in a long time and toxic components due to the oil spill and oil slick disasters can not only affect directly, very seriously marine creatures, plants and life of other animals but also they pollute the air environment and reduce the health of human. Some activities such as the waterway accidents, the tanker or bilge discharges, and the acts of wanton vandalism are the main causes that pollute the ocean environment. The regulations of many countries such as the prevention of oil spill, reducing maximally the effects of the oil spill, and speeding up the oil spill degradation are to aim at treating and recovering fast, efficiently oil spills and oil slicks. The selection of suitable techniques for oil spill recovery and treatment depends on many factors such as the spilled oil volume, oil type, weather conditions (wind velocity), sea conditions (current velocity and wave height), cost and the fact situations of each country. In this paper, four methods used for oil spill recovery including physical-, chemical-, thermal-, and biodegradation method are introduced. The structure of mechanical devices including booms, skimmers and absorbent materials, the properties of chemicals such as dispersants and solidifies, the methods based on the thermal technologies, the major microorganisms for oil degradation for oil spill recovery, treatment and cleanup are analyzed. Each mentioned method also shows the advantages and disadvantages, as well as its applicability. The selection of suitable method for oil spill recovery purpose on the basis of the available equipment and techniques must be ensure that the collected oil spill volume is the largest, the period of time for recovery process is the shortest, aiming at minimizing the negative effects on the human, marine ecosystem, social economy.
        4,800원
        171.
        2018.06 구독 인증기관 무료, 개인회원 유료
        In recent years, much interest has been devoted to bio-fuels because of their beneficial effects on environment, agriculture and economic development. Raw vegetable oil – a kind of bio-fuels, still exits many downsides, is potential renewable fuel replaced for ever-exhausted fossil fuel. In this report, vegetable oil which is available in the South of Vietnam such as raw coconut oil is studied by heating up different temperature with the aim at decreasing its high viscosity and density and meeting the fuel requirements. The experiments are conducted on heated coconut oil (HCO) and fossil diesel oil (DO) using an 80hp of small marine diesel engine. The results of engine performance as using DO and HCO included engine power (Ne), specific fuel consumption (SFC), thermal efficiency (TE), emission characteristics such as carbon monoxide (CO), unburned hydrocarbon (HC), smoke, nitrogen oxides (NOx) at internal feature are measured. The experiment results show higher SFC, CO, HC and smoke emissions, and lower TE, and NOx emissions for HCO with respect to DO. In addition, this study also reveals that, 1000C of HCO is said to be the most suitable heating temperature as getting the engine performance equals to DO.
        4,000원
        172.
        2018.05 구독 인증기관·개인회원 무료
        Recently, there is an increasing the pavement distresses such as rutting with an increase in heavy vehicles on the road in Mongolia. Rutting is the longitudinal depression in the wheel path in asphalt pavements and it causes a hydroplaning and severe safety concern for users. This study aims to develop paving material that can prevent rutting on the road pavement by improving the durability of the asphalt mixture in Mongolia. Therefore, this study was carried out using the technique of reinforcing the material by adding fibers to conventional asphalt mixture. Fibers have been used to reinforce various materials for many decades in various parts of the world. It is generally understood that asphalt is strong in compression and weak in tension. Adding fibers with high tensile strength can help increase the strength of a mixture[1]. A mixture of glass fibers was used in this study to evaluate the performance characteristics. In coordination with the City of Ulaanbaatar, The test section selected in this study was Peace Avenue in Ulaanbaatar. The test section was a bus lane with severe rutting by heavy vehicles. The designated road test section performed cutting and overlay using five asphalt mixtures: Glass Fiber-reinforced Asphalt, Hot Mix Asphalt(10mm, 19mm), Polymer Modify Asphalt(2 types). The performance survey was conducted after the summer. As a result, No noticeable cracks were observed in glass-reinforced mixture section and the rut-depth of the glass-reinforced mixture is lower than other mixtures[2].
        173.
        2018.05 구독 인증기관·개인회원 무료
        One major concern of Seoul City is the premature failure occurrence such as fatigue cracking and rutting in the pavement. Due to the acceleration at intersections and low vehicle speed at bus stops that cause higher shear and critical strain on the pavement. Because of this, there is a need to develop a new mixture that can withstand bus stop and intersection traffic while preventing premature failure. In this study, a high modulus asphalt mixture was adapted and developed to address the cracking and rutting concerns at bus stops and intersections of Seoul City. Indirect tensile (IDT) and beam fatigue testing were conducted to determine the fatigue performance of the high modulus asphalt mixture (HMB). In addition, the behaviour of the HMB considering loading speed and temperature were investigated using the IDT dynamic modulus test. It was found that the HMB performs 3 and 1.5 times better compared to conventional asphalt using IDT and beam fatigue test respectively. Moreover, it was observed that modulus value of HMB is two times better at low frequency (high temperature) compared to conventional asphalt. The dynamic modulus value of the HMB was then used as input for bus stop and intersection scenario analyses. It was found that HMB can reduce the total thickness of the pavement around 4 to 6cm compared to the conventional asphalt. It can be concluded that because of the better fatigue and rutting performance and high modulus value of HMB at low frequency, it can perform better in bus stops and intersections. It is recommended to conduct field construction to further evaluate the performance of HMB asphalt mixtures in the field.
        174.
        2018.05 구독 인증기관·개인회원 무료
        In Vietnam, reclaimed asphalt pavement technology is considered as the key to reduce the cost of pavement construction, and decrease the industrial waste from flexible pavement rehabilitation. Ministry of Transportation has concentrated to develop RAP technology since 2008. As a result, there are three trademark of recycling technologies applied in Vietnam such as Wirtgen (Germany), Hall Brothers (U.S.), and Sakai (Japan). This paper is focused on asphalt pavement investigation of field and laboratory tests from Cold In-place recycling technology. The laboratory tests carried out on the material were conventional tests including Marshall stability, indirect tensile strength... Field data was collected using a Benkelman beam and core specimens for indirect tensile strength test.
        175.
        2018.05 구독 인증기관·개인회원 무료
        When piles adjacent to deep excavations (i.e. tunnel operation), pile for slope stabilization, highway embankments near abutment piles in soft soil, the load generates lateral soil movement on pile. The lateral soil movement leads to develop the horizontal pressure between the pile and soil, also increase deflection as well as bending moment in the pile. In order to investigate a single pile subjected to horizontal loads due to the movement of the upper soil layer, the pile and soils are modelled by using 3D finite element analysis in this paper. The finite element analysis software used in this study is ANSYS. Furthermore, the soil's elastic behaviour follows the Mohr-Coulomb model and the pair of contact elements is used to simulate the pile-soil contact. A good correlation between laboratory and predicted results is observed in the validation analysis. The parametric study also demonstrates that soil Young's modulus and soil movement profile are key factors in predicting the behaviour of the pile.
        176.
        2018.05 구독 인증기관·개인회원 무료
        Kathmandu is the capital city of Himalayan country Nepal. It is a bowl shaped small valley with 3.5 Million populations. With approximately 5000 lane- km of roads and about 40% of entire vehicle populations of the country plying here without any grade separation, it has become quite challenging to manage the smooth flow of traffic in the city. The population of motor bikes is 75% making the job of traffic management difficult. Lack of foot path and bi cycle lanes for pedestrians and NMT and the narrow streets with manually controlled traffic intersections further complicate the deteriorating traffic flow. The improvement efforts including widening of critical roads could produce short term results only. A project named Kathmandu valley Sustainable Urban Transport Project, KSUTP funded by ADB could not progress as desired. This paper discusses the problems, studies and measures being undertaken to resolve these issues.
        177.
        2018.05 구독 인증기관·개인회원 무료
        Road network in the Mekong Delta is mostly coastal and river routes, then they are often flooded when the floods come in. As a result, the foundation and pavement are destroyed, reduced life expectancy, resulting in unsafety in traffic, cost of maintenance and repairs…. This paper establishes the technical conditions for the calculation on the flexible pavement working in the wet conditions (so flooded) based on the maximum usage of available materials in the provinces in the Mekong Delta. Simultaneously, we propose the flooded flexible pavement under the current climate change conditions.
        178.
        2018.05 구독 인증기관·개인회원 무료
        Fly ash is used as alumina-silicate resource material to reaction processing on geopolymer materials. The strength of material is belonging to alkaline liquid, fly ash, activity reaction of fly ash. Geopolymer concrete as non-toxic, bleed free and high strength material can be used for construction on rigid pavement. Study on influence of polypropylene fiber on performance characteristic of geopolymer concrete is considered. In this research, the mix proportion with fly ash and alkaline liquid is used to react on geopolymer concrete. The poly-propylene fiber in range from 0 to 0.5% by volume is added in mixture of geopolymer concrete. The ratio between length and diameter in range of 100-500 is investigated. The results are indicated that workability of fresh concrete is reduced by using poly-propylene fiber. The adding of poly-propylene fiber is significantly affected on characteristic of geopolymer concrete. Poly-propylene fiber can be distributed in fly ash matrix and reduced shrinkage of concrete during activation. After geopolymerization, compressive and the flexural strength of concrete produced with fibers are enhanced up to 10% and 20%, respectively. However, when the length to diameter ratio increases, compressive strength is tended to decrease with mixture using polypropylene fiber.
        180.
        2018.04 구독 인증기관·개인회원 무료
        Methyl benzoate (MB) is a natural compound in many plants and shows insecticidal toxicity against various insect pests. We determined contact, fumigant, and repellent activities of MB against the sweetpotato whitefly Bemisia tabaci and the greenhouse whitefly Trialeurodes vaporariorum (Hemiptera: Aleyrodidae). Complete contact mortality was obtained by 4% MB. Contact mortality at 2% MB into eggs, 4th instar nymphs and adults were 69.4%, 91.6% and 80%, respectively. Fumigation of 2% MB killed 95% of adults. In addition, treatment of 4% MB repelled 60% adults. There was no significant different between two species. Our results suggest that MB has high potential as an natural pesticide for sustainable pest management in crop production.