본 연구는 국내에서 아직 식품색소로 지정되지 않은 zeaxanthin과 citranaxanthin에 고성능 액체 크로마토그래피 (HPLC)를 적용하여 최적화된 동시 분석법을 개발하고, 이 분석법을 검증하기 위해 수행되었다. 최적의 분석법을 확립하기 위해, 기존에 보고된 다양한 국외 문헌 시험법의 HPLC 분석법을 비교 검토하였다. 그리고 분석 조건 선정 시 선형성, 검출한계(LOD), 정량한계(LOQ), 정확성, 반복 성, 실험실 간 검증 등의 주요 검증 항목을 고려하여 다 양한 식품에 적용 가능한 최적 전처리법을 개발하였다. 개 발된 분석법은 우수한 선형성(R20.999)을 나타내었으며, 식품 매트릭스 내에서 zeaxanthin과 citranaxanthin에 대한 검 출한계(LOD)는 각각 0.11-0.32 mg/kg 및 0.14-0.20 mg/kg, 정량한계(LOQ)는 각각 0.33-0.96 mg/kg 및 0.42-0.60 mg/kg 으로 확인되었다. 기존 연구에 보고된 전처리 방법은 다 양한 식품군에 적용하는 데에 한계를 보였으나, 본 연구 에서 개발된 분석법은 카로티노이드 착색료가 사용되는 주요 식품군에서 모두 적용이 가능하였다. 특히 이 방법 은 적용성 평가에서 zeaxanthin과 citranaxanthin에 대해 모 든 식품군에서 90% 이상의 우수한 동시 회수율을 나타내 었다. 또한, 새로운 HPLC 분석법을 적용한 두 물질의 정 확도(회수율) 및 정밀도(%RSD)는 식품의약품안전처(MFDS) 가이드라인에서 제시한 기준 범위에 부합하였다. 따라서 본 연구에서 개발된 동시 분석법은 식품 중 zeaxanthin과 citranaxanthin을 신뢰성 있고 정확하게 분석할 수 있는 방 법으로 판단되었다.

In this study, we addressed the prevention of fire extinguishing device malfunction caused by noise in the fire detector of automatic fire extinguishing devices applied to mobile equipment such as armored vehicles and tanks. The automatic fire extinguishing system consists of a fire detection unit, an automatic control unit, and a fire suppression unit. In the case of a fire detector, it is a major component of the fire detection unit. Even though no fire occurred during operation in the field, a number of fire extinguisher sprays occurred, and the malfunction of the fire detector, which is a fire detection unit, was reproduced. The cause was identified as noise in the fire detector connector due to vibration and shock that may occur during operation of the mobility equipment. In order to solve this problem, noise generated momentarily from a fire detector is treated as an exception, and when a fire signal is transmitted from the fire detector to the automatic control unit for more than a certain period of time, Software has been improved to enable fire extinguishers to operate. This study analyzed the causes of malfunctions in automatic fire extinguishing devices, which are components of mobile equipment, and derived improvement measures to improve the reliability of automatic fire extinguishing devices.

To overcome the challenges in tracking insects underground, a detection method consisting of a metal detector and aluminum tag was developed for tracking a dung beetle, Copris ochus (Coleoptera: Scarabaeidae). First, detection rate was evaluated for varying volumes of aluminum tags varying orientations of the tags under soil. Then, the detection efficacy was evaluated in the field at varying depths of hidden tags in two types of vegetation. Finally, the effect of aluminum-tagging on the survivorship, burrowing depth, and horizontal movement of C. ochus adults were assessed. Generally, an increase in tag volume resulted in a greater detection depth with maximum depth of 17 cm. Orientation, however, did not affect detection rate except when tag was placed perpendicular to the soil surface. In the field, metal detectors could detect aluminum-tagged models with success rates ≥85% up to 10 cm and 45−60% at 20 cm under soil. Finally, no significant effect of tagging on survivorship and behaviors of C. ochus was observed.

This paper proposes a solution to the out-of band oscillation signal and in-band low transmitter power output that occurrs during the low-temperature operation test for the new mine detector GPR signal transmission and reception module. Tests were performed by applying the optimal values of capacitors and inductors through circuit analysis simulation under the limited space, as a result, it was confirmed that the gain and return loss were improved at all-band thereby preventing oscillation signal and low transmitter power output.

This study developed a scenario to understand the reaction rate and operational time according to RTI value of rate of rise detector in each type in case of fire mattress. In the results of analyzing the reaction rate and operational time of detector in each scenario, in case when installing a single detector, the elevated temperature per minute was raised to 8℃/min ~ 9℃/min. In case when installing two detectors, it was raised to 9℃/min ~ 10℃/min. In case when installing three detectors, it was raised to 10℃/min. The horizontal distance between detector and mattress was 1.8m~2.5m. Whenever the number of detectors was increased, the horizontal distance was decreased. The operational time of detector was within maximum 540 seconds and minimum 420 seconds. As the research tasks in the future, there should be the researches on the effects of reaction rate of detector on the evacuation in case of fire through the result value of RSET by setting up the latency until the detector operates, and the researches on the safety by understanding if the operational time of detector is suitable for the evaluation standard of performancecentered design.

본 연구는 조제유류 중 지방산에 대해 최신 분석법을 마련하고자 수행하였다. 조제유류 중 지방산 함량 분석을 위해 GC를 이용한 분석법을 확립하고 시중에 유통 중인 제품을 대상으로 적용성을 검토하였다. 분석법 검증은 특이성, 직선성, 검출한계 및 정량한계, 정확성, 정밀성에 대해 수행되었다. Linoleic acid 및 α-linolenic acid의 0.1-5 mg/ mL 농도범위에서 R2=0.999 이상의 우수한 직선성을 확인할 수 있었다. Linoleic acid 및 α-linolenic acid의 LOD는 각각 0.06 mg/mL, 0.01 mg/mL, LOQ는 각각 0.16 mg/mL, 0.03 mg/mL였다. 표준인증물질 분석을 통해 정확성을 검토 하였으며, linoleic acid 및 α-linolenic acid의 회수율은 각각 100.8%와 101.1%로 확인하였다. 정밀성을 검토한 결과 시료 채취량에 따른 반복성은 linoleic acid 1.4-2.9%, α- linolenic acid 1.1-2.7%이었고, 실험실간 재현성은 각각 2.8%, 1.5%임을 확인하였다. 본 연구에서 확립된 분석법을 적용하여 국내 유통 중인 조제유류 및 조제식 제품 12건에 대해 적용성 검토를 실시한 결과 전체 시료에서 분석이 용이 하였으며, 모두 기준·규격에 적합함을 확인하였다. 본 결과로부터 확립된 GC를 이용한 분석법은 조제유류 중 지방산 함량을 확인하기에 적합함을 확인하였으며 국내 식품 영양 성분의 관리 기반을 강화하는데 기여할 것으로 사료된다.

The purpose of this study is to develop and apply an oil leak detector using a capacitive sensor to detect oil leak in hydraulic equipment. The developed oil leak detector consists of a sensor and a sensing circuit. The sensor is designed using the difference in the permittivity of air and oil to change the capacitance, and the sensing circuit is composed of a charge amplifier and rectifier circuit. The sensing device is made of a PCB module to output the DC analog signal. In this study, this oil detector was installed in a cyclic pressure tester for evaluating valve life and was applied to detect the leakage of the test valve. It can also be applied to detecting the oil leakage of various hydraulic types of equipment and reduce maintenance costs by preventing large leakage of hydraulic oil.

A study of the tissue depletion of florfenicol (FFC) administered orally to pigs at a dose of 0.05 kg/ton feed for 7 days was performed. Sixteen healthy cross swine were administered with FFC. Four treated animals were arbitrarily selected to be sacrificed 1, 3 and 5 days after the end of treatment. FFC residue concentrations in muscle, liver, kidney, and fat were determined using high-performance liquid chromatography (HPLC) with ultraviolet photometric detector at 230 nm. The correlation coefficient (R2) of the calibration curve for florfenicol amine (FFCa) was > 0.997 and the limits of detection and quantification were 0.012 and 0.040 μg/mL, respectively. Recovery rates in swine edible tissues ranged from 79.1 to 93.5%. In the FFC-treated group, FFC residues at 3 days post-treatment were below the maximum residue limits (MRLs) in muscle, kidney and fat, and those at 5 days post-administration were below the MRLs in all edible tissues. These results suggest that the withdrawal period of FFC after the drug treatment might be 5 days, which is a sufficient amount of time for reduction of the FFC residues below the MRLs in all edible tissues.

A numerical method is proposed to calculate the response of detectors measuring particle energies from incident isotropic fluxes of electrons and positive ions. The isotropic flux is generated by injecting particles moving radially inward on a hypothetical, spherical surface encompassing the detectors. A geometric projection of the field-of-view from the detectors onto the spherical surface allows for the identification of initial positions and momenta corresponding to the clear field-of-view of the detectors. The contamination of detector responses by particles penetrating through, or scattering off, the structure is also similarly identified by tracing the initial positions and momenta of the detected particles. The relative contribution from the contaminating particles is calculated using GEANT4 to obtain the geometric factor of the instrument as a function of the energy. This calculation clearly shows that the geometric factor is a strong function of incident particle energies. The current investigation provides a simple and decisive method to analyze the instrument geometric factor, which is a complicated function of contributions from the anticipated field-of-view particles, together with penetrating or scattered particles.

Conventional chemical ecology approach for identification of semiochemicals from natural sources is based on isolation of active ingredients after fraction and bioassay. Instead, we identify potential semiochemicals using reverse chemical ecology approach. In this way, we discovered an odorant receptor (CquiOR136) for DEET, which was not know how and why it work. Additionally, we identified a link between this synthetic repellent and methyl jasmonate, thus suggesting that DEET might work by mimicking defensive methyl jasmoante from plant. Moreover, we serendipitously found that a receptor, CquiOR36, responded to an old sample of nonanal in ethanol. Careful investigation led us to identify the active ligand as acetaldehyde (derived from ethanol) from “contaminants” in the old nonanal sample. We explored that acetaldehyde in a wide range of dose both attracts gravid mosquito and stimulate them to lay eggs in oviposition trays.