In an automotive plant, an automated storage and retrieval system (ASRS) synchronizes material handling flows from a part production line to an auto-assembly line. The part production line transfers parts on small-/large-sized pallets. The products on pallets are temporarily stored on the ASRS, and the ASRS retrieves the products upon request from the auto-assembly line. Each ASRS aisle is equipped with narrow-/wide-width racks for two pallet sizes. An ASRS aisle with narrow-/wide-width racks improves both storage space utilization and crane utilization while requiring delicate ASRS aisle design, i.e., the locations of the narrow-/wide-width racks in an ASRS aisle, and proper operation policies affect the ASRS performance over demand fluctuations. We focus on operation policies involving a common storage zone using wide-width racks for two pallet sizes and a storage-retrieval job-change for a crane based on assembly-line batch size. We model a discrete-event simulation model and conduct extensive experiments to evaluate operation policies. The simulation results address the best ASRS aisle design and suggest the most effective operation policies for the aisle design.

본 연구는 코팅 방법을 활용한 단결정 양극 소재 연구로서 Ni-rich계 다결정 양극 소재로 부터 단결정 양극 소재를 합 성하여 사이클 구동 시 양극 소재의 안정성을 향상시키고자 한다. 양극 소재에 LixCoO2와 LixSnO3 를 각각 코팅하여 이차입자 내부 혹은 외부에 코팅층이 형성된 양극 소재를 합성한 후 이를 소결하여 단결정 형성에 대한 영향을 비교 하였다. 입자 외부에 LixSnO3가 코팅되어 열처리 된 Ni0.8Co0.1Mn0.1O2(NCM811)의 경우 코팅 처리 없이 열처리된 양극 소재 보다 개선된 수명특성을 보였으나, 단결정화가 이뤄지지 않았다. 입자 내부에 LixCoO2 코팅층이 형성된 NCM811 을 열처리 한 결과 이차입자 내부에 형성된 Co 코팅층이 결정화되어 50회 사이클 후 기준 단결정 양극 소재의 방전용 량인 117.34 mAh·g-1 대비 129.11 mAh·g-1의 높은 방전용량을 나타내었고, 형상제어를 통해 이성적인 단결정화가 이뤄 졌다. 본 연구는 다결정체인 Ni-rich 양극소재의 단결정화에 대한 유요한 통찰력을 제공할 것으로 예상한다.

In additive manufacturing, the flowability of feedstock particles determines the quality of the parts that are affected by different parameters, including the chemistry and morphology of the powders and particle size distribution. In this study, the microstructures and flowabilities of gas-atomized heat-resistant alloys for additive manufacturing applications are investigated. A KHR45A alloy powder with a composition of Fe-30Cr-40Mn-1.8Nb (wt.%) is fabricated using gas atomization process. The microstructure and effect of powder chemistry and morphology on the flow behavior are investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and revolution powder analysis. The results reveal the formation of spherical particles composed of single-phase FCC dendritic structures after gas atomization. SEM observations show variations in the microstructures of the powder particles with different size distributions. Elemental distribution maps, line scans, and high-resolution XPS results indicate the presence of a Si-rich oxide accompanied by Fe, Cr, and Nb metal oxides in the outer layer of the powders. The flowability behavior is found to be induced by the particle size distribution, which can be attributed to the interparticle interactions and friction of particles with different sizes.

본 연구의 목적은 어머니의 주중 미디어 놀이 횟수가 유아의 놀이상호작용에 미치는 영향에서 자기통제와 주의집중문제의 매개역할을 살펴보는 것이다. 이를 위해 육아정책연구소의 한국아동패널 7차년도 데이터를 사용했고, 자료는 R 4.1.3과 PROCESS macro v4.1 for R로 분석했다. 본 연구의 결과는 다음과 같다. 첫째, 어 머니의 주중 미디어 놀이 횟수는 유아의 자기통제에 부적 영향, 주의집중문제에 정적 영향을 미쳤다. 또래 놀이상호작용에 대해 자기통제는 정적 영향, 주의집중문제는 부적 영향을 미쳤다. 자기통제는 주의집중문제 에 부적 영향을 미쳤다. 둘째, 어머니의 주중 미디어 놀이 횟수가 유아의 또래놀이상호작용에 미치는 영향 에서 자기통제와 주의집중문제는 각각 부적 매개효과가 나타났다. 마지막으로 어머니의 주중 미디어 놀이 횟수가 유아의 또래놀이상호작용에 미치는 영향에서 자기통제와 주의집중문제는 부적 직렬다중매개효과가 있었다. 본 연구의 결과는 유아의 자기통제와 주의집중문제가 어머니의 주중 미디어 놀이 횟수와 또래놀이 상호작용을 매개하는 주요한 요인임을 시사한다.

동아시아가 원산지로 추정되며, 2007년에 신종으로 보고된 콩바구미아과(Bruchinae)에 속하는 Bruchidius siliquastri Delobel (박태기콩바 구미; 신칭)는 유럽에서 콩과(Fabaceae)인 유다박태기나무(Cercis siliquastrum L.)의 종자를 가해하는 침입종으로 간주되고 있다. 이 콩바구미는 한국에서 최근 블로거(blogger)들에 의해 정확한 동정이 이루어지지 않은 상태로 성충 사진들이 업로드(upload) 되고 있으며, 또한 저자들은 2022 년 봄 순천대학교 캠퍼스에 식재된 박태기나무(C. chinensis Bunge)에서 일부 생태 및 가해를 관찰할 수 있었다. 본 연구는 한국에서 이 콩바구미의 새로운 생활사 정보를 제공하고자 한다.

Untreated waste is temporarily stored on the site of the nuclear power plant. In some nuclear power plants, saturation period of temporary storage waste is less than 10 years away. As untreated waste continues to be generated in nuclear power plants, it could also affect management of operations. Accordingly, CRI is developing the 3.5 generation plasma torch melting facility for waste treatment. The 3.5th generation plasma torch melting facility consists of melter, plasma torch, waste supply device, exhaust gas treatment facility, power supply, etc. Melter is composed of melting chamber for melting control and pyrolysis chamber for waste pretreatment, and dam-type discharge device is adopted to overflow the melt. Plasma torch is hollow type with reversed discharge, has a rating of megawatt class, and has two gas supply lines. It can be used in transfer mode, non-transfer mode and mixed mode. There are three types of device for waste supply. The first is a drum pusher for injecting 200 L drums, the second is a screw-type waste supply and hopper for injecting solid waste, and the third is a nozzle-type waste supply device for injecting liquid waste. Exhaust gas treatment facility was equipped with post combustion chamber, off-gas cooler, high-temperature filter, HEPA filter, reheater, scrubber, ID fan and etc. Power supply of plasma torch operation is designed with a capacity of 1.5 megawatt (Maximum) and consists of channels A and B. Transfer mode, non-transfer mode and mixing mode of plasma torch may be selected through the control of PLC. This paper introduces the composition and function of the 3.5th generation plasma torch melting facility of CRI. In order to solve the problems arising through the operation of the 3rd generation plasma torch melting facility, an optimization plan is applied.

The high-level nuclear waste (HLW) repository is a 500-1,000 m deep geological disposal system with a very long life expectancy for disposing of high-level waste, which is known to have a half-life of several thousand years. This repository is subject to harsh environmental conditions, such as high temperature and radiation from high-level waste, that can cause deterioration and crack. When radiation escapes through cracks, it can injure persons on the ground. Therefore, it is essential to install a sensor that can detect problems such as cracks. But, since the high-level nuclear waste (HLW) repository is sealed with bentonite and backfill, the sensor cannot be removed or replaced once it has been installed. Therefore, it is necessary to develop a highly durable monitoring sensor that can withstand harsh environmental conditions. Before attempting to improve durability, it is first required to assess durability quantitatively. And an accelerated life test is a widely used method for assessing durability. However, it is important to obtain the same failure mode when conducting a reliability test, such as an accelerated life test. If the accelerated life test is conducted using different failure modes, the dependability of the results is inevitably diminished. Therefore, in this study, a representative failure mode for the piezoelectric sensor used in the accelerated life test was derived through experiments and literature research.