Leaf-spray in vitro bioassays appraise new aphicidal formulations for managing deleterious plant-feeding aphids. The formulation may utilize alternative and integrated strategies. However, leaf spraying even under controlled conditions may affect aphid reproduction and mortality. This study examines leaf spray applications for optimum and reproducible aphicidal results using tobacco leaves overlaid on cotton fabric or water agar surfaces. Infestation of the undersides of tobacco leaves with nymphs of green peach aphids was used in the assays. Spray distance and volume were optimized using water-sensitive paper to ascertain the best surface coverage. Overlays of the leaves on water agar caused less mortality and greater reproduction than the use of cotton fabric. The relative humidity of the insect-rearing chambers changed with the watering regime for the insect - rearing chambers with cotton fabric; 60% relative humidity was optimal. Relative humidity was not affected by the concentration of agar in the water agar chambers. Applications of the chemical aphicidal standard, Sulfoxaflor, under the optimized conditions exhibited similar times for lethality although the rate was faster with leaves on the cotton fabric than on water agar. These studies establish reproducible and sensitive techniques for assessing the lethality and effects on reproduction of potential aphicidal products.

The utilization of methyl bromide (MB) for quarantine purposes has been hampered by its designation as an ozone-depleting substance under the Montreal Protocol. The International Plant Protection Convention's (IPPC) call for alternatives to MB and a reduction in its usage. There is an urgent need to explore and implement substitutes. Despite some substitute agents like EDN being developed for wood, EDN has been limited due to various factors such as occupational risks. This study focuses on evaluating the efficacy of Sulfuryl Fluoride (SF) as a viable alternative fumigant against Reticulitermes speratus, one of major wood destroying pests. Experimental trials conducted at ambient temperature (23°C) revealed promising results, with SF demonstrating LCT50 and LCT99 values of 30.87 mg·h/L and 42.53 mg·h/L, respectively. Under low-temperature conditions (5°C), SF remained effective but with slightly higher LCT50 and LCT99 values of 151.62 mg·h/L and 401.90 mg·h/L, respectively. The penetration test, conducted using R. speratus-infested pine wood cubes, further highlighted SF's efficacy, with LCT50 and LCT99 values of 31.59 mg·h/L and 53.34mg·h/L at 23°C, indicating powerful penetration capabilities. When tested at a loading ratio of 90% (v/v) at 5.0mg/L for 24 hours in a 500L chamber as a middle-scale trial, SF achieved a 100% mortality, showing its potential as a suitable replacement for MB. These findings suggest that SF could open new markets as an MB substitute and enhance safety at quarantine sites when applied to imported and exported timber.

진딧물 방제제 개발을 위해 In vitro 경엽살포 검정방법이 널리 사용되고 있다. 이러한 신소재 진딧물 방제 제형은 종합방제와 화학농약의 대안 으로 많은 연구가 진행되고 있다. 하지만, 경엽살포 검정방법은 환경이 조절되는 실내에서도 진딧물의 증식과 살충에 영향을 받는다. 본 연구에서는 담배를 기주로 하여 솜과 한천방법을 이용하여 진딧물 방제제 검정을 위한 최적 경엽살포 확립하고자 하였다. 진딧물 검정 챔버에 솜과 한천을 넣은 후 담배 잎과 진딧물 3-4령 약충을 접종하였다. Water-sensitive paper를 이용하여 경엽살포 시에 가장 표면 피복이 높은 최적 경엽살포 거리와 살 포량을 확립하였다. 대조구로 물을 처리한 구에서 한천 방법이 솜 방법에 비해 살충율이 낮고, 증식율이 높았다. 솜 검정 방법에는 곤충 검정 챔버의 상대습도를 60% 이상 유지시켰을 때 가장 최적 조건이었지만, 한천 검정 방법에서는 한천의 농도에 상대습도 차이가 없었다. 최적화된 조건하에서 대조화학 농약, Sulfoxaflor, 경엽살포 시 솜 방법에서 살충율이 한천방법보다 빨랐지만, 최종 살충율은 통계적으로 유의하지 않았다. 본 연구는 살 진딧물 물질을 검정 시 재현성과 활용성이 가능한 최적화된 증식율과 살충율 검정 조건을 제시하였다.

Given the domestic situation, all nuclear power plants are located at the seaside, where interim storage sites are also likely to be located and maritime transportation is considered inevitable. Currently, Korea does not have an independently developed maritime transportation risk assessment code, and no research has been conducted to evaluate the release rate of radioactive waste from a submerged transportation cask in the sea. Therefore, secure technology is necessary to assess the impact of immersion accidents and establish a regulatory framework to assess, mitigate, and prevent maritime transportation accidents causing serious radiological consequences. The flow rate through a gap in a containment boundary should be calculated to determine the accurate release rate of radionuclides. The fluid flow through the micro-scale gap can be evaluated by combining the flow inside and outside the transportation cask. In this study, detailed computational fluid dynamic and simplified models are constructed to evaluate the internal flow in a transportation cask and to capture the flow and heat transfer around the transportation cask in the sea, respectively. In the future, fluid flow through the gap will be evaluated by coupling the models developed in this study.

As the saturation rate of temporary storage facilities for spent nuclear fuel increases, regulatory demands such as interim storage and permanent disposal of spent nuclear fuel are expected to begin in earnest. Considering the domestic situation where all nuclear power plants are located on the waterfront site, the interim storage site is also likely to be located on the waterfront site, and maritime transportation is one of the essential management stages. Currently, there are no independently developed maritime transportation risk assessment code in Korea, and no research has been conducted to evaluate the release of radioactive waste due to the sinking of transport container. Therefore, it is necessary to secure technology to properly reflect the domestic maritime transportation environment and to assess the impact of the sinking accident and to carry out safety regulations. To accurately calculate the releaser rate of radionuclides contained in a cask with breached containment boundary, the flow rate through the gap generated in the containment boundary should be calculated. The fluid flow through this gap which is probably in micro scale in most situations should be evaluated combining the fluid flow inside and outside the cask. In this study, a detailed computational fluid dynamics model to evaluate the internal fluid flow in the cask and a simplified model to capture the fluid flow and the heat transfer around the cask in the sea are constructed. The results for the large scale model are compared with the analytic formula for verification of heat transfer coefficient and they showed good agreements. The heat transfer coefficient thus found can be used in the detailed model to provide more realistic data than those obtained from assumed heat transfer coefficient around the surface of the cask. In the future, fluid flow through the gap between the lid and the body of the cask will be evaluated coupling the models developed in this work.

Currently, in domestic nuclear power plants (NPP), the spent filters (SFs) used for the purpose of reducing and purifying the radiation of the primary cooling water system are temporarily stored in an untreated state. In order to dispose of SFs, radioactive nuclide analysis (RNA) of SFs is required to be conducted. As segmented gamma scanner (SGS) is already being used in Kori NPP, utilizing SGS for RNA of SFs would be practical and economical. In this paper, factors required to be considered to improve accuracy of SGSs for RNA of SFs are studied. The analysis of the nuclide inventory of the packaging drum for radioactive waste should be performed by the indirect drum nuclide analysis method. The material of the SFs is iron (SS304) on the outside, and paper on the inside. In addition, to meet disposal acceptance criteria, radioactive waste drums are packaged in thick grouting or shielding drums. Therefore, it is necessary to derive an appropriate correction method for high inhomogeneity and thick media. Considering these factors, evaluating radionuclides inventory plans to measure gamma rays in SGS mode. Correct the gamma ray measurement by examining the medium attenuation factor and error factors. In this way, the inventory of gamma nuclides is calculated, and the specific radioactivity of beta ray and alpha particle emitting nuclides other than gamma rays is planned to be calculated by applying scaling factors.

본 논문에서는 폭발하중을 받는 부재의 저항성능 평가를 위한 모멘트-곡률 관계 기반 수치해석 기법을 소개한다. 직접전단 파괴 모 드를 고려하기 위하여 경험적인 직접전단응력-슬립양 관계를 기반으로 하는 무차원 스프링 요소를 도입하였다. 재료에 대해 정의된 동적증가계수 식을 바탕으로 단면의 모멘트-곡률 관계에 직접적으로 적용가능한 단면의 곡률 변화율에 따른 동적증가계수 식을 제작 하였다. 또한 부착슬립의 영향을 고려하기 위하여 소성힌지영역 내에 등가 휨강성을 도입하였다. 제안된 수치해석 모델의 타당성 검 증을 위하여 실험결과와의 비교연구를 수행하였으며, 단자유도계 모델의 해석결과와의 비교를 통해 본 수치해석 모델의 우수성을 확 인하였다. P-I 선도를 제작하여 부재의 휨 파괴 및 직접전단 파괴에 대한 저항성능을 평가하였으며, 매개변수 연구를 수행하여 P-I 선 도 및 저항성능의 변화를 확인하였다.

As the demand for the monitoring of VOCs increases, various unpowered colorimetric sensors are being developed, but the performance evaluation method of the developed sensors has not been systematically established. In this study, the device, experimental process, and data calculation methods for the performance evaluation of the colorimetric sensors were proposed. An aluminum chamber (70W× 128 L × 40 mm H) was designed to expose the sensor to a constant concentration of VOCs. In addition, an experimental apparatus was devised to evaluate the effect of environmental factors (temperature and humidity) affecting the ability of the sensor to detect VOCs. To calculate the color change value of the sensor corresponding to the concentration of VOCs, the ‘peak wavelength method’ that analyzes the wavelength of the highest intensity for high-concentration VOCs and the ‘spectral centroid method’ using a weighted arithmetic average for low-concentration VOCs were used. As a result of evaluating the ability of the colorimetric sensor to detect VOCs, which was made of polydimethylsiloxane (PMDS) by the method proposed in this study, the wavelength change values (bandgap shift) of the sensor for 1,000 ppm of benzene, toluene, oxylene, and acetone were 0.898 nm, 2.304 nm, 5.775 nm, and 0.249 nm, respectively. The precision was calculated by repeatedly measuring the sensing ability of the sensor 5 times for each type of VOCs. The precision of the sensor responses to benzene, toluene, o-xylene, and acetone were 15.23%, 7.84%, 4.14%, and 30.00% RSD, respectively. The method proposed in this study can be used to evaluate the performance of various types of VOCs colorimetric sensors.

PURPOSES : This study defines travel time reliability as a concept that explains the change in travel time that passengers can hardly predict and calculates the value of travel time reliability based on travel objectives. METHODS : Because the reliability of passage time is difficult to estimate from actual passenger data, standard quantification measures have not been established despite various interests. In this study, the reliability of transit time was defined as the expense that passengers did not recognize in advance, such as an accidental delay caused by unforeseen circumstances. For analysis based on the individual behavior of users, the data were constructed using the optional experiment method (marginal rate of substitution method) of the stated preference survey, which has the advantage of controlling the correlation between attribute variables and maintaining the independence of the data of the study. RESULTS : Consequently, the reliability value of travel time in mandatory-purposed traffic was almost identical to the value of travel time, and the reliability value of travel time in return and shopping/leisure, which is not mandatory during non-business-purpose traffic, is lower than the value of travel time. Comparing and analyzing with existing studies on estimating the reliability value of transit time, both work/ non-work purposes are in line with the overall research results. CONCLUSIONS : Estimating the reliability value of transit time for each purpose of passage was the first attempt, and it is meaningful to suggest a direction for quantifying and applying the reliability value of transit time along with the passage time value of this study.