식품매개 감염은 여전히 세계 공중보건의 중대한 위협 이다. 특히 저산성 통조림 및 레토르트 제품에서 내열성 포자를 형성하는 Clostridium botulinum에 의해 부각되며, 해당 미생물의 생장·독소 생성 가능성을 확실히 차단하는 열처리 공정 설계가 필수적이다. 증기-공기혼합 레토르트 는 과압 상태에서 증기와 공기를 혼합하여 가열하는 방식 으로, 공기의 낮은 열전달계수로 인해 ‘콜드 스팟(cold spot)’이 형성될 위험이 있다. 따라서, 본 연구는 증기-공 기혼합(air-steam) 레토르트의 공정 최적화를 위해 95oC 및 121oC 조건에서 다지점(대차 상·중·하부 12지점/트레이별 5구간)으로 정량 평가하고, 적재밀도(12, 18, 28개), 스팀 공급량(100, 90, 80%), 가압(0.3-0.7 및 1.3-1.7 kgf/cm2)이 균일가열성과 살균값(F₀)에 미치는 영향을 분석하였다. 기 준 온도계 대비 최대 편차는 ΔT=1.1oC로 IFTPS 허용범위 이내였으나, 냉점(cold spot)은 일관되게 하부(D3_d)에서 확인되었고, 과적재(28개) 시 CUT 지연과 온도편차 확대 가 발생하였다. 스팀공급 저하(특히 80%)와 저가압(0.3 또 는 1.3 kgf/cm2)은 목표온도 미도달·분산 증가를 야기했으 며, 이는 냉점의 F₀ 유의 저하로 연결되었다(예: 121oC에 서 스팀 100% 대비 80% 조건의 D3_d F₀ 16.729.01). 반면, 충분한 스팀품질·환기(venting)와 적정 가압(1.5-1.7 kgf/cm²) 유지 시 공간적 균일성과 목표 F₀ 확보가 용이하였다. 결과적으로 레토르트 운전의 핵심 관리포인트는 적 정 적재·트레이 통기성 확보, 주증기 공급능력 및 노즐 스 케일 관리, 벤팅·순환 성능 검증, 공정단계별 정밀 압력제 어이며, HD에서 HP 순의 검증체계를 통해 냉점 기준으 로 과살균을 최소화하면서 규제수준의 상업적 멸균을 보 장할 수 있음을 제시한다. 본 연구는 산업현장에서 적용 가능한 운영 프로토콜을 제안함으로써 레토르트 열살균 공정의 품질·안전 관리에 실증적 근거를 제공한다.

In this study, GNPs/FeCoNiCuAl particles synergistically reinforced aluminum matrix composites are developed by friction stir processing (FSP) to explore the effects of different GNPs contents (1, 3, and 5%) on the microstructure, mechanical performance, and wear resistance of the materials. The results show that the incorporation of GNPs affects the formation of the diffusion layer between the FeCoNiCuAl particles and the aluminum matrix. As the content of GNPs increases, the thickness and integrity of the diffusion layer between FeCoNiCuAl particles and aluminum matrix gradually decrease. In addition, the introduction of GNPs is beneficial in enhancing the proportion of high-angle grain boundaries in the composites, but the grain size of the specimen increases slightly to about 5.5 μm at a content of 5% GNPs. When the content of GNPs is 1%, the composites achieve the highest microhardness and the lowest specific wear rate (0.1459 × 10⁻⁶ mm3/ N·m), with the wear mechanism dominated by abrasive wear. Nonetheless, when the GNPs content in the composite increases to 5%, the thickness and integrity of the diffusion layer are minimal, causing the tensile strength of the composite to be reduced to 250 MPa, and the specific wear rate increased to 0.4244 × 10– 6 ( mm3/N·m), with the wear mechanism transformed to abrasive–adhesive mixed wear. This study demonstrates that the appropriate ratio of GNPs and FeCoNiCuAl particles can effectively enhance the mechanical and wear resistance properties of aluminum matrix composites, providing a theoretical basis for the design and development of high-performance aluminum matrix composites.

Photocurable polymer components fabricated via 3D printing often exhibit rough surfaces and visible layer marks due to the inherent characteristics of additive manufacturing. Consequently, post-processing is frequently required to improve the external appearance of the final product. Since surface finishing is typically performed through machining, the appropriate selection of machining parameters is critical to prevent thermal-induced surface damage, particularly given the low heat-deflection temperature of polymer materials. Moreover, the mechanical properties of photocurable resins vary depending on resin composition and curing conditions, which also affect machinability. Therefore, baseline machining experiments are necessary to determine the optimal post-processing conditions for printed components. In this study, machining experiments were conducted on polymer specimens fabricated using a DLP (Digital Light Processing) system by varying spindle speed, feed rate, and depth of cut to optimize surface finishing conditions. The results indicate that the most improved surface roughness, approximately Ra 0.4 μm, was achieved under the conditions of 20,000 RPM spindle speed, 60 mm/min feed rate, and 100 μm depth of cut. This represents a 14-fold improvement compared to the pre-machining surface roughness. These optimized conditions are expected to be applied to the post-processing of porous scaffold core molds in future work.

리튬 이온 배터리의 안전성과 지속가능성에 대한 수요 증가는 기존의 폴리올레핀 분리막을 대체할 수 있는 셀룰 로오스 기반 분리막 개발을 촉진하고 있다. 본 총설은 수압 공정을 통해 제조된 셀룰로오스 아세테이트(cellulose acetate, CA) 분리막의 최적화 전략을 종합적으로 분석하였다. 특히, 기공 구조, 열적 안정성, 기계적 강도를 조절하는 데 있어 유기 및 무 기 첨가제의 역할을 중점적으로 고찰하였다. 유기산은 고분자 사슬의 가소화를 통해 나노기공 형성을 유도하여 높은 기공률 과 조절 가능한 기공 크기를 제공하지만, 열적 안정성이 다소 저하되는 한계가 있다. 반면, 무기 염과 산화물, 특히 칼슘계 화 합물은 이온 상호작용과 가교결합을 통해 열적 안정성을 크게 향상시키는 것으로 나타났다.

Aluminum nitride (AlN) provides excellent thermal conductivity and electrical insulation, making it suitable for semiconductor heater applications. However, its low surface emissivity can lead to thermal energy loss, reducing heater efficiency. To address this issue, black AlN - obtained by doping with carbon and other impurities to enhance the surface emissivity - has recently been applied in various fields. In this study, black AlN was fabricated by adding TiO2 to AlN, and its densification behavior and electrical properties were evaluated to assess the feasibility of its use as a heater material for semiconductor photolithography. The sinterability of black AlN was improved by optimizing the granulation and forming conditions, with a particular focus on the heat treatment parameters that affect material properties such as color. Consequently, a black AlN heater material with a sintered density of 3.33 g/cm3, thermal conductivity of 162.7 W/m･K, and thermal diffusivity of 64.22 mm2/s was fabricated by optimizing the processing variables.

This study examined process–structure relationships in laser powder bed fusion of Al0.1CoCrFeNi + Cu composites, focusing on densification, elemental distribution, and solidification cracking. Mechanically mixed Al0.1CoCrFeNi and Cu powders were processed across a range of laser powers (100–250 W) and scan speeds (200–800 mm/s). Increased volumetric energy density (VED) improved densification, with a plateau near 200 J/mm3 yielding ~96% relative density; however, this value was still below application-grade thresholds. At low VED, insufficient thermal input and short melt pool residence times promoted Cu segregation, while higher VED facilitated improved elemental mixing. Elemental mapping showed partial co-segregation of Ni with Cu at low energies. Solidification cracks were observed across all processing conditions. In high VED regimes, cracking exhibited a minimal correlation with segregation behavior and was primarily attributed to steep thermal gradients, solidification shrinkage, and residual stress accumulation. In contrast, at low VED, pronounced Cu segregation appeared to exacerbate cracking through localized thermal and mechanical mismatch.

Italian ryegrass (Lolium multiflorum Lam., IRG) is a widely cultivated winter forage crop known for its high yield and nutritional value. This study evaluated the processing characteristics and feeding performance of IRG-based pellets in Hanwoo cattle (Bos taurus coreanae) and Korean native black goats (Capra hircus). IRG was harvested at the optimal growth stage and processed into two pellet formulations: IRG ≥80% (with up to 20% soybean meal) and 100% IRG. Feeding trials were conducted under ad libitum feeding conditions. Hanwoo cattle showed higher intake of 100% IRG pellets (7.9 kg/day/head) than IRG ≥80% pellets (7.5 kg/day/head, p<0.05), with similar average daily gain (0.9 ± 0.4 kg/day/head). Conversely, black goats exhibited significantly lower intake of IRG ≥80% pellets (54.6 g/day/head) compared to 100% IRG pellets (266 g/day/head), likely due to reduced palatability associated with soybean meal inclusion. These findings suggest that IRG pellets are suitable for Hanwoo cattle, while further optimization of pellet size and formulation is required to improve acceptance in goats. Future studies should assess long-term impacts on digestion, rumen fermentation, and metabolic responses.

The chip processing system of large scale machine tool, such as planomiller, turning machine, boring machine and CNC machine, has been continuously used in many industrial fields. As the performance of chip processing system is improved, cutting work with high-precision is also required. This study aims to study the characteristics of the edged part of cutter depending on removing the cutter support in cutter assembly. As the results, the damaged spot in edged part of cutter was different whether the cutter support was installed or not. By removing the cutter support, the safety factor of edged part of cutter was decreased about 4.7 times and furthermore there were some advantages in less than 1.7kN of cutting force.

본 연구는 ‘안정 상태(폐안/개안)’와 ‘인지처리 상태(추상적사고/언어적사고)’에서 측정된 뇌파를 통해 뇌 네트 워크의 연결성(PLV)을 계산하고, 이를 그래프이론의 지수들로 정량화하여 두 상태의 특성을 비교⋅분석하기 위한 목적으로 수행되었다. 네트워크의 특성을 구조화하기 위해 잠재프로파일분석을 통해 ‘안정 상태’에서 각각 3개의 프로파일과 ‘인지처리 상태’에서 공통으로 2개 프로파일을 식별하였으며, 그 결과에 대한 심리적 개인차의 타당성 을 확보하기 위하여 성격6요인 구조와의 영향관계를 검증하였다. 결과로써 개안상태의 뇌가 가장 높은 Efficiency 를 보여 정보처리의 비용 절감을 위해 효율적인 자원관리를 한다는 사실을 확인하였으며, 시각정보의 유무에 따른 ‘안정 상태’ 간의 유의미한 차이와 ‘추상적사고 처리상태’에서의 모듈화 경향을 확인하였다. 또한 LPA 프로파일의 특성 분류를 통해 인지처리의 종류가 달라져도 신경네트워크 수준에서는 공통된 패턴이 존재할 수 있다는 사실과 ‘빠르고 효율적인 국소적 처리’ 유형과 ‘느리지만 통합적인 분산 처리’의 전략이 차별적으로 존재함을 확인하였다. 본 연구의 결과는 뇌 네트워크의 기능적 연결성이 다양한 정신활동과 직접적으로 연관되어 있다는 사실을 뒷받침 한다.

This research aimed to find an eco-friendly way to neutralize water recovered from ready-mixed concrete by dissolving carbon dioxide in it, and to verify the potential use of such water for mixing concrete. Carbon dioxide was injected using nanobubble technology into recovered water, and the optimized conditions for dissolution were established by analyzing the carbon dioxide concentration in the water and measuring pH over time. Mortar was manufactured using this recovered water following carbon dioxide nanobubbles treatment, and measurements of compressive strength and thermogravimetric analysis (TGA) were conducted to verify the formation of calcium carbonate. 2,464 mg/L of carbon dioxide was dissolved in the recovered water, and the pH was measured to be 6.34. The compressive strength of the manufactured mortar was found to be 32.02 % stronger than mortar manufactured with normal tap water. According to the thermogravimetric analysis results, the amount of calcium hydroxide produced in the mortar manufactured with recovered water from ready-mixed concrete was 8.10 %, and the production amount of calcium carbonate was 6.49 %. This means that the amount of calcium carbonate produced was greater than that in mortar manufactured with normal tap water, as well as tap water containing nanobubble carbon dioxide. The carbon dioxide was stably dissolved in water recovered from ready-mixed concrete using nanobubbles, enabling environmentally friendly neutralization without the use of chemicals. Also, when the recovered water from ready-mixed concrete containing dissolved carbon dioxide was used for mixing concrete, it was determined that the carbonation reaction influenced the formation of calcium carbonate, which contributed to the improvement in concrete strength.