이 연구는 셀룰로오스 또는 실리카를 포함하고 있는 목재, 왕겨 및 축분 바이오차로 시멘트 또는 잔골재를 대체한 콘크리트 의 강도시험을 통하여 역학적 특성을 파악한 것이다. 시험결과에 따르면, 바이오차 종류에 따른 강도는 왕겨 바이오차 혼입 콘크리트가 가장 크고, 다음으로 목재 바이오차였으며, 축분 바이오차가 가장 낮은 것으로 나타났다. 그리고 시멘트 또는 잔골재의 대체율에 따른 콘크리트 강도는 왕겨 바이오차의 대체율이 증가할수록 강도가 감소하였으나, 목재 및 축분 바이오차의 경우에는 대체율에 따라 강도 가 증가 하였다. 또한, 바이오차를 혼입하지 않은 보통 콘크리트와 비교하여 왕겨, 목재 및 축분 바이오차 순으로 최대 강도가 90%에 서 99%까지였으며, 압축강도로 추정하는 휨강도 또는 쪼갬인장강도 또한 보통 콘크리트의 상관 계수와 비슷하였다. 이와 같은 시험결 과를 근거로, 바이오차를 혼합한 콘크리트의 역학적 특성은 대체율에 따른 차이에도 불구하고 보통 콘크리트와 비슷한 강도를 확보할 수 있으므로 바이오차를 콘크리트의 새로운 혼화재료로 사용할 수 있을 것으로 판단된다.

이 논문에서는 교량받침 교체용 통공앵커의 충전조건과 하중조건에 따른 구조적 안전성을 유한요소해석을 통해 확인하였다. 에폭시의 충전여부와 하중조건을 변수로 두어 통공앵커의 구조적 거동을 확인한 결과 에폭시 완충 시 앵커에 정적수평하중이 균등하게 작용하여 통공앵커가 작용하중에 저항하여 구조물의 국부적인 파괴를 방지 가능하였다.

This study explores the histological features and Bmp4 expression patterns in the replaced tooth germ of Xenopus laevis . Tooth germ formation starts from the dental placode through epithelial-mesenchymal interactions, involving various signaling pathways such as Fgf, Shh, Bmp, and Wnt. In mice, Bmp4 expression in the dental placode inhibits Pax9 expression in the dental mesenchyme. Although absent in the presumptive dental lamina of birds and toothless mammals, Bmp4 remains conserved in reptiles and fish owing to gene duplication. However, its expression in amphibian tooth germs is poorly understood. Three-month-old X. laevis were employed in this study. Initially, samples underwent paraffin embedding and were sectioned into 5 or 12 μm ribbons for H&E staining and in situ hybridization, respectively. Results revealed teeth appearing in two maxillary rows: the labial side, with prefunctional and functional teeth, and the lingual side, with replaced tooth germs behind functional teeth. Enameloid was observed between the inner dental epithelium and dental mesenchyme at the cap or early bell stages, whereas enamel and dentin formed during the late bell or mineralization stages from the replaced tooth germ. Bmp4 expression was evident in the inner dental epithelium (ameloblasts), dental papilla (odontoblasts), stellate reticulum, and Hertwig’s epithelial root sheath. Overall, these findings highlight the conservation of Bmp4 expression in X. laevis tooth development.

산업혁명 이후 화석연료 사용의 급격한 증가와 온실가스 배출이 심해져 온난화 경향이 심각해 탄소 배출을 절감하는 상황이 요구되고 있다. 본 연구는 탄소 격리 효과를 가지고 있는 바이오차와 콘크리 트의 취성을 극복하고 연성을 증가시켜 균열의 발생을 최소화하여 내구성을 향상 시킬 수 있는 PVA (Polyvinyl Acohol)섬유를 활용하여 기존의 콘크리트의 단점을 보완하고, 시멘트 저감 효과와 친환경 성을 갖춘 고연성 섬유보강 시멘트 복합체(ECC)를 제작하여 바이오차 시멘트 대체 비율에 따른 ECC 의 역학적 특성을 분석하고 비교하였다. 바이오차 시멘트 대체 비율 5%를 최대치로 설정하여 시멘트 대체 비율을 1%씩 올려 0%, 1%, 2%, 3%, 4%, 5%까지 설정하여 플로우 시험, 압축강도 실험, 쪼갬 인장 강도 실험, 휨 강도 실험을 진행하였다. 모르타르의 유동성을 평가하기 위해 플로우 시험을 실시 했으나, 바이오차 시멘트 대체 비율에 관계없이 플로우는 큰 차이를 보이지 않았다. 바이오차 시멘트 대체 비율에 따른 강도 비교를 위한 압축강도 실험, 쪼갬 인장 실험에서는 바이오차 시멘트 대체 비율 2%가 가장 높은 값을 보였다. 휨 강도 실험에서는 바이오차 시멘트 대체 비율 3%가 가장 큰 값을 보 였다. 휨 강도 실험에서는 바이오차를 혼입하지 않은 노말 ECC와 비교했을 때 바이오차의 시멘트 대 체율이 높아질수록 강도가 감소하였지만, 압축강도와 쪼갬 인장강도 실험에서는 대체율이 높아지면 강 도가 증가하는 경향이 나타났다.

This study addresses the environmental impact associated with waste management and natural aggregate production. It explores the potential of utilizing Coal Bottom Ash (CBA) and Reclaimed Asphalt Pavement Aggregate (RAPA) as complete replacements, respectively, for fine and coarse aggregates in concrete. Despite their similarities to natural aggregates, CBA and RAPA often end up in landfills. Laboratory tests were conducted, revealing satisfactory performance in drying shrinkage and air void parameters. However, while the flexural strength met design requirements, the compressive and splitting tensile strengths were lower than predicted. The deviation in strength development behavior from natural aggregate concrete (NAC) was attributed to weak agglomerated aggregates in RAPA and the large size of the interfacial transition zone (ITZ) due to the old asphalt coating surrounding RAPA. To enhance the strength behavior, two methods were employed: compaction in the form of roller-compacted concrete and RAPA abrasion carried out by rolling RAPA in a concrete mixer. Compaction improved aggregate interlock, while RAPA abrasion decreased agglomerated aggregates and minimized asphalt coating, reducing ITZ size. These treatments resulted in improvements in compressive, flexural, and splitting tensile strengths, with the combination of both treatments having the most significant effect. Analysis of relationships between flexural, splitting tensile, and compressive strengths indicated that CBA and RAPA concrete behaved more similarly to NAC after the treatments. This research suggests that with appropriate interventions, it is feasible to utilize CBA and RAPA in concrete, contributing to sustainable construction through improved waste management, carbon footprint reduction, and conservation of natural resources.

세계적으로 환경에 대한 관심이 커지면서, 탄소 저감 및 탄소 중립을 위한 다양한 연구들이 진행되고 있다. 특히 최 근에는 탄소 포집 및 저장 기술인 CCS(Carbon Capture and Storage)에 주목이 높아졌다. 그뿐만 아니라, 대기 중의 탄소를 효과 적으로 저장하는 특성을 가진 바이오차는 탄소 중립에 기여할 수 있는 방안으로 다양한 연구가 진행되고 있다. 건설 산업에서 는 시멘트 대체재를 활용한 탄소 감소 관련 연구가 진행 중이며, 본 연구에서는 바이오차를 콘크리트 및 모르타르의 시멘트 대 체재로 활용하여 시멘트 사용량을 줄이고, 동시에 콘크리트 및 모르타르 내의 탄소를 포집하고 저장하여 탄소 배출량을 감소시 키고자 한다. 이를 위해 바이오차의 시멘트 치환율을 0%, 10%, 20%로 설정하고, 각각의 경우에 대해 콘크리트 및 모르타르의 슬럼프, pH 농도, 그리고 압축강도를 비교하였다.실험 결과에 따르면, 바이오차의 시멘트 치환율이 증가함에 따라 슬럼프와 압 축강도가 감소하는 경향을 보였으며, pH는 유사한 양상을 나타냈다.

In this investigation, samples of the chemical (Hg1-xPbxBa2Ca1.8Mg0.2Cu3O8+δ) were prepared utilizing a solid-state reaction technique with a range of lead concentrations (x = 0.0, 0.05, 0.10, and 0.20). Specimens were pressed at 8 tons per square centimeter and then prepared at 1,138 K in the furnace. The crystalline structure and surface topography of all samples were examined using X-ray diffraction (XRD) and atomic force microscopy (AFM). X-ray diffraction results showed that all of the prepared samples had a tetragonal crystal structure. Also, the results showed that when lead was partially replaced with mercury, an increase in the lead value impacted the phase ratio, and lattice parameter values. The AFM results likewise showed excellent crystalline consistency and remarkable homogeneity during processing. The electrical resistivity was calculated as a function of temperature, and the results showed that all samples had a contagious behavior, as the resistivity decreased with decreasing temperature. The critical temperature was calculated and found to change, from 102, 96, 107, and 119 K, when increasing the lead values in the samples from 0.0 to 0.05, 0.10, and 0.20, respectively.

Background: Largemouth bass (Micropterus salmoides) is introduced species that has caused aquatic ecology activity both in vitro and in vivo were investigated for the possibility of application of the bass extract as an alternative feed ingredient. Methods: The bass oil was extracted using a 1-L supercritical extractor, while the protein was extracted from 250 g of bass dry matter, which was dissolved in 1 mL of H2O at 50℃. Both oil and protein extracts were evaluated antioxidant activities and the level of DPPH radical scavenging assay and nitric oxide (NO) production assay with lipopolysaccharide response. Oral administration of 6.6 μL/g bass protein and 5.38 μL/g bass oil conducted for investigating serological and physiological effect. Results: DPPH radical scavenging showed similar radical scavenging ability of 50 μM of ascorbic acid at 200 μg of protein and 10% of oil treatment. NO concentration was diminished by the treatment of bass oil. Oral administration of both bass oil and proteins to mice showed that the body weight increase rate of the bass oil treated group was significantly reduced by 1.55 g compared to the other groups. The number of white blood cells (WBC) was increased by 4.52 k/μL in the bass protein-treated group and 4.44 k/μL in the bass oil-treated group compared to the control group. However, the serum IgG level did not show a significant difference between the bass extract-treated groups and the control group. Conclusions: These studies demonstrate that both bass oil and proteins extracted from the bass not only provide excellent effects of antioxidant and immune activity but can also be used as functional food supplements.

This study evaluated the consumers’ demands and points of improvement for restaurant meal replacement through importance–performance analysis by the restaurant meal replacement segment market using food involvement. The results were as follows. First, after segmenting the restaurant meal replacement market using food involvement, it was classified into three markets (multiple involvements, exploration-oriented, and product quality-oriented). Second, an analysis of the importance of restaurant meal replacement selection attributes revealed taste, sanitation, quality, freshness, price, saving time, texture, ingredients, preparation process, and quantity to be highly important. An analysis of the differences according to the market type revealed the multiple involvement type to be more important than other groups, considering the restaurant meal replacement selection attribute element. Third, an analysis of the importance-performance analysis of restaurant meal replacement selection attributes revealed that quantity and price as the selection attributes that needed to be improved first in all three markets. In addition, in the multiple involvement type, food additives appeared as a selection attribute requiring priority improvement, revealing the characteristics of a market that cares about diet and health.

Among the nuclear power plant facility improvement projects, out of a total 10 replacement reactor vessel closure head (RRVCH), five have been replaced, starting with Gori Unit 1, and five, including Hanul Unit 1, Hanbit Units 5 and 6, and Hanul Units 3 and 4 will be replaced in the future. This paper presents the method of treating Latch Housing among radioactive waste generated during the replacement of Hanul Unit 2 (February 2023). Latch Housing controls the control rod by receiving magnetic force from the CRDM’s Coil Stack. Located in the Old Reactor Vessel Head (ORVH) Hot Spot, the range of measured radiation dose rate was 0.3 to 0.8 mSv h-1 (up to 4.5 mSv h-1). The amount of radioactive waste generated was 35.8 Baler-Drum (based on 200L), and the order of treatment was to cut into the Omega Seal of the CRDM, the CRDM and Latch Housing Transfer, the boundary of the CRDM and Latch Housing, the Rod Travel Housing, the Motor Housing and the Latch Assembly, and then transfer and Drumming. In the United States, out of 93 operating reactors, 31 reactor vessel heads have been replaced and 19 reactor vessel heads are scheduled to be replaced. In Korea, 25 reactors are in operation, and two reactors have been permanently shut down. Among them, the nine old reactors for more than 30 years (as of September 2021) are expected to achieve ALARA and reduce radwaste management costs through the management method applied to replace the reactor vessel head.

This paper proposes a standardized vehicle body repair manual for vehicles with major damage to the rear side members caused by rear-end collisions. The manual is used to refine the vehicles. Typical work involves replacing large traffic accident modes with new members or modifying and aligning existing members. If repairs are made for various reasons, the members should be attached based on the body of a new vehicle. Unlike new vehicle members, the accident vehicle repair process depends heavily on the operator's skilled skills (i.e., the performance, purpose, level, and quality of the body replacement work due to the nature of the vehicle body replacement work). When repairing or replacing a rear side member of a body repair, three methods of operation are applied because the damage and deformation vary depending on the object of the other party, although the degree of damage varies. There is no standardized manual for side member over-hole replacement, partial replacement, or partial modification, since these repair methods vary depending on the operator's thoughts and angle of view. Therefore, customers should use standardized vehicle repair manuals to ensure that their vehicle receives the same repair when damaged. This study is expected to develop a standardized vehicle repair manual to reduce the drop in used market prices after replacement or repair of rear side members at vehicle repair plants.

Background: Some patients may not fully recover their daily activity capabilities even after the total hip replacement (THR), and may continue to experience functional limitations for up to a year after the procedure, according to reports. Objectives: The purpose of this study was to examine the effects of machine squat on muscle strength, balance and gait in patients after THR. Design: A randomized controlled trial. Methods: Thirty-three patients after THR were randomly allocated into slide (n=11), reformer (n=11), and control groups (n=11). Each group underwent their respective squat regimens for thirty minutes, seven times a week, for two weeks. Muscle strength changes were assessed using the manual muscle test (MMT), balance was evaluated using the Berg Balance Scale (BBS), and gait analysis was performed using the 10-meter walk test (10MWT). Results: Significant changes in hip flexor and abductor strength were observed in the slide and reformer groups within each group (P<.05). The reformer group showed significant changes in hip extensor strength (P<.05). Significant improvements in BBS were observed in all three groups (P<.05). There were significant changes in 10MWT in the slide and reformer groups (P<.05). A significant difference in hip extensor strength was found between the reformer and control groups after the intervention (P<.0167). Significant differences in BBS were observed between the slide and reformer groups and between the reformer and control groups after the intervention (P<.0167). Conclusion: Our findings suggest that machine squat regimens can be effective for early rehabilitation after THR, improving muscle strength, balance, and gait.

Cars serve as vehicles for the conveyance of both passengers and cargo. Inevitably, traffic accidents constitute a significant facet of vehicular operation. These accidents manifest in various forms, including frontal, rear-end, and lateral collisions. While the resultant vehicular damages may exhibit similarities, they remain inherently distinct. Owing to the intricate nature of automotive body repairs, simplistic adherence to textbook doctrines proves inadequate. The rectification of damaged vehicle bodies hinges upon the practitioner's experiential acumen. Consequently, discourse pertaining to body repair technology necessitates grounding in empirical data encompassing prevailing industry norms and attendant financial implications. Variability in individualized methodologies can engender substantial temporal and monetary outlays within the domain of automotive bodywork. Moreover, the integration of novel material technologies within vehicular structures mandates a perpetual pursuit of knowledge and empirical inquiry into the domain of vehicle body repair procedures, particularly as applied to emerging materials. Compounding this imperative is the unwavering commitment to preserving the safety paradigm from the vehicle owner's perspective, ensuring that restorative interventions subsequent to accidents do not compromise safety benchmarks.