Hydrogen has a wide flammability range and rapidly diffuses in air, making precision detection technology essential to prevent explosion risks and ensure system safety as the adoption of hydrogen infrastructure expands. Polymer materials are employed in such infrastructure to seal high-pressure hydrogen, and reliable measurement techniques capable of quantifying trace amounts of hydrogen permeating or leaking through these materials is necessary. In this study, a hydrogen quantification system combining volumetric analysis with image analysis was utilized to evaluate the hydrogen uptake and diffusivity of HDPE (high-density polyethylene), NBR (nitrile butadiene rubber), and EPDM (ethylene propylene diene monomer) under high-pressure conditions. The results indicated that HDPE and NBR samples containing silica filler exhibited hydrogen uptake behavior consistent with Henry’s law, while EPDM samples with carbon black filler demonstrated additional hydrogen adsorption on the carbon black surface. These research results provide a foundation for more precisely evaluating the permeation and leakage behavior of polymers in high-pressure hydrogen environments, and are expected to contribute to the safe and efficient development of hydrogen infrastructure.

This study determined the appropriate pressure for high pressure shucking of oysters (Magallana gigas) according to size categories. One-year and two-year-old oysters harvested from Yeosu and Tongyeong coastal areas were subjected to high pressure treatments with pressure ranging from 180 to 240 MPa and holding times of 0 to 420 seconds. Results demonstrated that 100% shucking rates were achieved at 220 MPa with 120-180 seconds holding time regardless of harvest time and production area. K-means cluster analysis was used to classify oyster specimens into small, medium, and large size groups with mean shell heights of 69.0 mm, 86.6 mm, and 106.7 mm, respectively. The analysis revealed that shucking efficiency improved directly proportional to oyster size. However, the appropriate shucking pressures converged at approximately 220 MPa for all size groups, with small, medium, and large groups showing 218.9 MPa, 221.7 MPa, and 220.6 MPa, respectively, and no significant differences among groups. These findings suggest that the appropriate pressure for high pressure shucking processes be approximately 220 MPa regardless of harvest time and production area, providing foundational data for potential automation of oyster shucking processes.

A high-pressure in-situ permeation measuring system was developed to evaluate the hydrogen permeation properties of polymer sealing materials in hydrogen environments up to 100 MPa. This system employs the manometric method, utilizing a compact and portable manometer to measure the permeated hydrogen over time, following high-pressure hydrogen injection. By utilizing a self-developed permeation-diffusion analysis program, this system enables precise evaluation of permeation properties, including permeability, diffusivity and solubility. To apply the developed system to high-pressure hydrogen permeation tests, the hydrogen permeation properties of ethylene propylene diene monomer (EPDM) materials containing silica fillers, specifically designed for gas seal in high-pressure hydrogen environments, were evaluated. The permeation measurements were conducted under pressure conditions ranging from 5 MPa to 90 MPa. The results showed that as pressure increased, hydrogen permeability and diffusivity decreased, while solubility remained constant regardless of pressure. Finally, the reliability of this system was confirmed through uncertainty analysis of the permeation measurements, with all results falling within an uncertainty of 11.2 %.

This study investigated the effects of different emulsification techniques—high-pressure homogenization (HPH) and ultrasonic homogenization (USH)—on the properties of β-glucan-loaded liposomes under varying operational conditions. The results showed that, in HPH, increasing both the pressure (5,000–15,000 psi) and the number of cycles (1–3) gradually reduced the average particle size of the liposomes, with all particles remaining below 200 nm and a polydispersity index (PDI) under 0.1, with no significant differences (p>0.05). Liposomes produced with USH at the lowest energy level (20% amplitude for 1 min) exhibited the largest average particle size (594.63 nm) and greatest size variation. However, increasing the power and duration of USH reduced both the liposome size and PDI, making them comparable to those produced by HPH. Turbidity improved with increasing energy in both methods (p<0.05), although the turbidity ranges differed: HPH ranged 0.243–0.839 and USH, 0.628–1.715. Overall, this study demonstrates that HPH is more effective than USH in producing stable β-glucan liposomes.

In this study, in order to develop an eco-friendly filtration method that considers the health and safety of the aquatic ecosystem by differentiating it from chemical methods (coagulants, oxidants, etc.), which are mainly used as methods for managing the removal of algae in the algal bloom stage, an effective separation membrane for algae removal was reviewed, an appropriate technology was proposed through field application, and the effect of algae removal was evaluated. The membrane used was applied in the field by constructing an optimal technology through auxiliary facilities with an immersion tubular membrane and a pressurized tubular membrane resistant to adhesive pollutants and algae. As a result, the strong characteristics of Fouling (blocking) by adhesive algae were confirmed, and the effect of removing algae and particulate matter in the immersion type tubular membrane was 99% chlorophyll-a (Chl-a), 99.2% suspended solid (SS), and 96.7% of pressurized tubular membranes, showing excellent effects in removing algae and particulate organic matter. In addition, as a result of field application to eutrophic reservoirs where high-density algae are distributed, it was confirmed that stable operation of algae was possible during the process of filtering, separation, and concentration.

As the number of households with pets has increased worldwide, there is a growing trend of accepting pets as family members. Consequently, the pet food market has seen the emergence of concepts such as “human-grade,” “raw (PMR and BARF),” and “no synthetic additives” pet food. These concepts not only fulfill essential nutrients but also consider the health and habits of pets, a crucial aspect that should be at the forefront of our work. However, these types of pet food are prone to microbial contamination and component alterations caused by heat. Current studies and products have recently been developed overseas to apply non-thermal sterilization technologies to pet food commonly used in the food industry. In contrast, the domestic standards for non-thermal sterilization in pet food are insufficient. Therefore, a comprehensive review of non-thermal sterilization technologies, such as high-pressure processing (HPP), radiation, and plasma predominantly applied in the international pet food market, is deemed necessary. This review is expected to provide guidelines for non-thermal sterilization standards in domestic pet food, thereby laying the foundation for the safe production of raw pet food.

우리나라 열병합 발전소에서 운영되고 있는 최신 증기터빈의 출력과 효율 향상을 위한 첫 번째 기술적인 진보는 고온, 고압의 증기를 사용할 수 있는 소재 개발의 진척이라고 할 수 있다. 소재의 발전과 더불어 증기터빈의 내부효율 향상을 위한 설계적 노력의 결실 로 높은 효율의 증기터빈이 제작되었다. 오랜 기간 운전 중인 증기터빈의 내부효율은 기계적 수명의 한계로 점차 손실이 발생하고 효율 과 출력이 떨어지게 된다. 이러한 이유로 본 연구에서는 상용프로그램을 이용하여 열병합 발전소용 고압(HP)-중압(IP) 증기터빈의 증기유 로 성능해석을 수행할 수 있는 모델을 개발하고 성능계산 방법을 제시하고자 한다. 증기터빈의 복잡한 성능계산방식으로 인해 증기터빈 실무자들에게 실질적으로 유용한 참고문헌이 될 수 있도록 주요 변수들을 제시하였다. 또한 증기터빈 성능계산에 필요한 열정산도 분석 과 증기터빈 성능계산 결과의 적합성을 성능시험 결과와 비교 확인하였다.

생물환경조절학회지 30권 3호에 게재된 논문의 그래프를 수정합니다.

High-pressure sodium (HPS) lamps have been widely used as a useful supplemental light source to emit sufficient photosynthetically active radiation and provide a radiant heat, which contribute the heat requirement in greenhouses. The objective of this study to analyze the thermal characteristics of HPS lamp and thermal behavior in supplemented greenhouse, and evaluate the performance of a horizontal leaf temperature of sweet pepper plants using computational fluid dynamics (CFD) simulation. We simulated horizontal leaf temperature on upper canopy according to three growth stage scenarios, which represented 1.0, 1.6, and 2.2 plant height, respectively. We also measured vertical leaf and air temperature accompanied by heat generation of HPS lamps. There was large leaf to air temperature differential due to non-uniformity in temperature. In our numerical calculation, thermal energy of HPS lamps contributed of 50.1% the total heat requirement on Dec. 2022. The CFD model was validated by comparing measured and simulated data at the same operating condition. Mean absolute error and root mean square error were below 0.5, which means the CFD simulation values were highly accurate. Our result about vertical leaf and air temperature can be used in decision making for efficient thermal energy management and crop growth.

We report the behaviour of carbon black (CB) nanoparticles (spherical carbon shells), subjected to external pressure, using diamond anvil cell at synchrotron facility. CB nanoparticles have been synthesized by lamp black method using olive oil as combustion precursor and ferrocene as an organometallic additive. The catalyst-assisted CB has an iron oxide (γ-Fe2O3) core and amorphous carbon shell (i.e. core–shell structure). Our present study suggests that the carbon shells are partially transparent to the applied high pressure, and result in the reduction of effective pressure that gets transferred to the iron oxide core. High-pressure Raman spectroscopy results indicate that the surrounding carbon shells get compressed with pressure and this change is reversible. However, no structural transformation was observed till the highest applied pressure (25 GPa). The Raman spectroscopy results also suggests that the carbon shells are less pressure sensitive as their pressure coefficients (dω/dP) of G-peak were calculated (3.79 cm− 1/GPa) to be less than that for other carbon allotropes.

수산물을 활용한 반려묘 간식개발을 위하여 명태, 조피볼락, 넙치, 돌돔, 연어 및 참치 등의 부산물을 고압고온에서 삶아 그 농축액을 반려묘에게 급여하였다. 반려묘의 기호도가 높은 실험구는 연어와 참치 농축액이었다. 여기에 통영에서 생산되는 멸치, 홍합 및 굴 건조물을 분쇄하여 첨가한 결과 모든 구에서 섭식행동을 나타내었다. 시중에 판매되고 있는 기존의 반려묘 간식과 차별화를 위하여 멍게껍질에 함유된 콘드로이친황산(ChS)을 추출하고 일정량을 연어 및 참치 농축액에 첨가하여 섭식을 실험한 결과 모두 잘 먹는 것으로 나타났다. 과잉생산 된 수산건제품을 반려묘 간식 개발에 활용할 수 있어 수산부산물의 활용방안을 제시할 수 있을 것으로 판단된다.

By applying super-high pressure (150-250 MPa) to a sealed pressure vessel, it is possible to make oyster shucking machine that automatically opens two-sheet shellfish or oysters. Possibility of developing a shucking machine was confirmed by identifying the working pressure for meat of oysters produced in the southern coast and conducting sensory evaluation of meat oysters. As a result of confirming the shucked oysters under super-high pressure of 150 MPa in the pressure vessel, the number of type A with separated shells and well-separated meat was 22 and type B with both shells and internal meat and shells not separated. For the oysters that were treated at 175 MPa, there were 58 type As with shell separated and meat well separated and 42 type Bs without oyster shells and insides. When looking at the oysters shucked at 200 MPa in the pressure vessel, the number of type A was 86 and type B was 14 accounting for 86% of oysters with good marketability. As a result of shucking oysters by applying 250 MPa, 96% type A oysters and 4% type B oysters were obtained from the total specimen. The total specimen oyster weight used in the conducted experiment was 6 kg, the average oyster shell weight was 3.99 kg and the average oyster meat weight was 1.25 kg. Therefore, the fatness of oyster meat, which measures the added value of oysters, is 20.8%. Sensory evaluation was conducted on thinned oysters by hand and type A oysters shelled by machine with an operating pressure of 200 MPa. The hand-worked oyster sample scored 4.7 points only in salty taste, and scored 5.0 or higher in color, shape, smell, fishy taste, texture and preference.