• Title/Summary/Keyword: chemical states

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Trends in truffle mushroom utilization technology: A patent database survey through the first half of 2023 (트러플 활용기술 동향: 2023년 상반기까지의 특허를 중심으로)

  • Hyun-Suk Kim;Moon-Hee Choi;Deuk-Sil Oh;Hyun-Jae Shin
    • Journal of Mushroom
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    • v.21 no.3
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    • pp.88-92
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    • 2023
  • In this review, we examine the latest technological developments in the utilization of truffles, a gourmet ingredient reputed to be one of the "world's three greatest delicacies," considering changing global consumption trends. Global demand for truffles is expected to increase steadily, with an average annual growth rate of 8.9% from 2023 to 2030. As truffles are expensive, the demand for truffles is expected to be concentrated in developed countries such as the United States, European countries, and Japan. In Korea, truffles are utilized in various industries, including food, functional foods, and cosmetics. Korean consumer demand for truffles has consistently remained high since 2019, and truffle products have been performing well in the market. Consequently, there exists substantial potential demand for newly developed truffle-related products and technologies. This review aims to provide objective research information through the systematic analysis of patent applications in Korea and internationally, focusing on technologies involving truffles, and can aid in setting directions for research and development.

Continuous Process for the Etching, Rinsing and Drying of MEMS Using Supercritical Carbon Dioxide (초임계 이산화탄소를 이용한 미세전자기계시스템의 식각, 세정, 건조 연속 공정)

  • Min, Seon Ki;Han, Gap Su;You, Seong-sik
    • Korean Chemical Engineering Research
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    • v.53 no.5
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    • pp.557-564
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    • 2015
  • The previous etching, rinsing and drying processes of wafers for MEMS (microelectromechanical system) using SC-$CO_2$ (supercritical-$CO_2$) consists of two steps. Firstly, MEMS-wafers are etched by organic solvent in a separate etching equipment from the high pressure dryer and then moved to the high pressure dryer to rinse and dry them using SC-$CO_2$. We found that the previous two step process could be applied to etch and dry wafers for MEMS but could not confirm the reproducibility through several experiments. We thought the cause of that was the stiction of structures occurring due to vaporization of the etching solvent during moving MEMS wafer to high pressure dryer after etching it outside. In order to improve the structure stiction problem, we designed a continuous process for etching, rinsing and drying MEMS-wafers using SC-$CO_2$ without moving them. And we also wanted to know relations of states of carbon dioxide (gas, liquid, supercritical fluid) to the structure stiction problem. In the case of using gas carbon dioxide (3 MPa, $25^{\circ}C$) as an etching solvent, we could obtain well-treated MEMS-wafers without stiction and confirm the reproducibility of experimental results. The quantity of rinsing solvent used could be also reduced compared with the previous technology. In the case of using liquid carbon dioxide (3 MPa, $5^{\circ}C$, we could not obtain well-treated MEMS-wafers without stiction due to the phase separation of between liquid carbon dioxide and etching co-solvent(acetone). In the case of using SC-$CO_2$ (7.5 Mpa, $40^{\circ}C$), we had as good results as those of the case using gas-$CO_2$. Besides the processing time was shortened compared with that of the case of using gas-$CO_2$.

Current and Future Perspectives of Lung Organoid and Lung-on-chip in Biomedical and Pharmaceutical Applications

  • Junhyoung Lee;Jimin Park;Sanghun Kim;Esther Han;Sungho Maeng;Jiyou Han
    • Journal of Life Science
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    • v.34 no.5
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    • pp.339-355
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    • 2024
  • The pulmonary system is a highly complex system that can only be understood by integrating its functional and structural aspects. Hence, in vivo animal models are generally used for pathological studies of pulmonary diseases and the evaluation of inhalation toxicity. However, to reduce the number of animals used in experimentation and with the consideration of animal welfare, alternative methods have been extensively developed. Notably, the Organization for Economic Co-operation and Development (OECD) and the United States Environmental Protection Agency (USEPA) have agreed to prohibit animal testing after 2030. Therefore, the latest advances in biotechnology are revolutionizing the approach to developing in vitro inhalation models. For example, lung organ-on-a-chip (OoC) and organoid models have been intensively studied alongside advancements in three-dimensional (3D) bioprinting and microfluidic systems. These modeling systems can more precisely imitate the complex biological environment compared to traditional in vivo animal experiments. This review paper addresses multiple aspects of the recent in vitro modeling systems of lung OoC and organoids. It includes discussions on the use of endothelial cells, epithelial cells, and fibroblasts composed of lung alveoli generated from pluripotent stem cells or cancer cells. Moreover, it covers lung air-liquid interface (ALI) systems, transwell membrane materials, and in silico models using artificial intelligence (AI) for the establishment and evaluation of in vitro pulmonary systems.

Amendments and Construction Systems for Improving the Performance of Sand-Based Putting Greens (골프장 putitng green 개선을 위한 토양 개량제와 green 구조시설)

  • Ok Chang-Ho;Anderson Stephen H.;Ervin Erik H.
    • Asian Journal of Turfgrass Science
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    • v.18 no.3
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    • pp.149-163
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    • 2004
  • Physical and chemical properties of root zone mixes and methods of green construction are important considerations for improving turf grass quality for putting greens. This study compared Penncross creeping bentgrass (Agrostis palustris Huds.) performance as affected by three root zone construction systems with three amendments (sand, peat, and zeolite). The objective of this study was to determine if an amended California construction system would improve green performance during establishment (1998-1999) and maturation (2000-2001). Three treatments were tested: California ($100\%$ sand), USGA($90\%$ sand and $10\%$ peat, v/v), and California-Z ($85\%$ sand and $15\%$ zeolite, v/v). Treatments were arranged in a randomized complete block with four replicates. Physical and chemical properties of the root zone and bentgrass performance were compared for the treatments. The California-Z treatment had the highest saturated hydraulic conductivity, field infiltration rate and the lowest bulk density. It also had the highest cation exchange capacity and plant available nutrient concentrations among the three treatments. The California-Z treatment produced bentgrass quality and color during green establishment and maturation that were equal to or higher than the California treatment, and consistently higher than the USGA treatment. The addition of an inorganic amendment to the California system improved physical and chemical properties of the root zone and improved quality and color of bentgrass during green establishment. During green maturation, creeping bentgrass in the California-Z treatment was equal (6 of 15 sampling dates) or $20\%$ higher (9 of 15 dates) in quality compared to the California system.

Optical Properties of SiNx Thin Films Grown by PECVD at 200℃ (200℃의 저온에서 PECVD 기법으로 성장한 SiNx 박막의 열처리에 따른 광학적 특성 변화 규명)

  • Lee, Kyung-Su;Kim, Eun-Kyeom;Son, Dae-Ho;Kim, Jeong-Ho;Yim, Tae-Kyung;An, Seung-Man;Park, Kyoung-Wan
    • Journal of the Korean Vacuum Society
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    • v.20 no.1
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    • pp.42-49
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    • 2011
  • We deposited $SiN_x$ thin films by using PECVD technique at $200^{\circ}C$ with various flow ratios of the $SiH_4/N_2$ gases. The photoluminescence measurements revealed that the maximum emission wavelength shifted to long wavelength as the ratio increased, however, positions of the several peak wavelengths, such as 1.9, 2.2, 2.4, and 3.1 eV, were independent on the ratio. Changes of the photoluminescence spectra were measured in the $N_{2}-$, $H_{2}-$, and $O_2$-annealed films. The luminescence intensities increased after the annealing process. In particular, the maximum emission wavelength shifted to short wavelength after $H_{2}-$ or $O_2$-annealing. But there were still several peaks on the spectra of all annealed films, several peak positions remained to be unchanged after the annealing. As for the light emission mechanism, we have considered the defect states of the Si- and N- dangling bonds in the $SiN_x$ energy gap, so that the energy transitions from/to the conduction/valence bands and the defect states in the gap were attributed to the light emission in the $SiN_x$ films. The experimental results point to the possibility of a Si-based light emission materials for flexible Si-based electro-optic devices.

Crystallization and Magnetic Properties of Iron Doped La-Ba-Mn-O (Fe이 치환된 LaBaMnO계 산화물의 중성자 회절 및 Messbauer분광학연구)

  • Choi, Kang-Ryong;Kim, Sam-Jin;Shim, In-Bo;Kim, Chul-Sung
    • Journal of the Korean Magnetics Society
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    • v.14 no.1
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    • pp.38-44
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    • 2004
  • The iron doped colossal magnetoresistance materials with La-Ba-Mn-O perovskites structure have been synthesized by chemical reaction of sol-gel methods. Their crystallographic and magnetic properties have been studied with x-ray diffraction, VSM, RBS, Mossbauer spectroscopy, and magnetoresistance measurements. The crystal structure of the La$\_$0.67/Ba$\_$0.33/Mn$\_$0.99/Fe$\_$0.01/ $O_3$ at room temperature was determined to be orthorhombic of Pnma. The lattice parameters a$\_$0/ and c$\_$0/ increased gradually, but b$\_$0/ deceased with increase of iron substitution. The magnetization and coercivity deceased, also the Curie temperature decreased from 360 K as x increased from 0.00 to 0.05. Magnetoresistence measurements were carried out, and the maximum MR ($\Delta$$\rho$/$\rho$(0)) was observed at 281 K, about 9.5 % in 10 kOe. The temperature of maximum resistance (R$\_$MAX/) decreased with increasing substitution of Fe ions and a semiconductor-metal transition temperature (T$\_$SC-M/) decreased too. This phenomena show that ferromagnetic transition temperature decreased by substituting Fe for Mn ions, it decreases double exchange interaction. This result accords with magnetic structure of neutron diffraction. Mossbauer spectra of La$\_$0.67/Ba$\_$0.33/Mn$\_$0.99/Fe$\_$0.01/ $O_3$were taken at various temperatures ranging from 15 to 350 K. With lowering temperature of the sample, two magnetic phases were increased and finally it showed the two sharp sextets of spectra at 15 K. The isomer shift at all temperature range is about 0.3 mm/s relative to Fe metal, which means that both Fe ions are Fe$\^$3+/ states.Fe$\^$3+/ states.

The Physiologic change associated with aging, essential nutrients and their diseases in senior or geriatric dogs (노령견의 생리적 변화에 따른 필요 영양소 및 질병에 관한 연구)

  • Jung, Hyung-hak
    • Journal of the Korean Applied Science and Technology
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    • v.35 no.4
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    • pp.1456-1471
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    • 2018
  • This article discusses the nutritional requirements, reviews senior or geriatric dog nutritional evaluation, and then addresses some common nutrition-related problems in older dogs. The purpose of this study was to investigate the Physiologic change associated with aging, essential nutrients and their diseases in senior or geriatric dog subjects. According to a 2002 market research, 30% to 40% of dogs raisedin the United States are 7 years of age. In Europe the number of dogs considered to be "senior or geriatric" (>7 years of age) increased by approximately 50% between 1983 and 1995. A 2012 e-mail survey of 50,347 respondents revealed that 33.2% of dogs were 6 to 10 years of age and 14.7% were older than 11 years in the United States. The average life expectancy of dogs raised in the home is affected by health care, aging and nutrition.And, the aging process is influenced by breed size, genetics, nutrition, environment, and other factors. Although many pets remain active and youthful well into their teens, most dogs start to slow down and may show signs of aging beginning as early as 5 or 6 years of age. Improvements in the control of various diseases and in the nutrition of dogs have resulted in a gradual increase in the average lifespan of companion dogs. Nutritional goals for aging dogs include supporting health and vitality, preventing the onset or slowing the progression of age-related health disorders, and enhancing the dog's quality of life and, if possible, life expectancy. Aging brings with its physiologicchanges. Some changes are obvious, such as whitening of hair, a general decline in body and coat condition, and failing senses including sight and hearing. Other changes are less obvious, however, and these include alterations in the physiology of the digestive tract, immune system, kidneys, and other organs. Nutritional requirements can change with age. In addition, many diseases common in older dogs may be nutrient-sensitive, meaning that diet can play an important role in the management of the condition.

A New Study of Sensing and Optimum Preparation Conditions of Graphite/Different Paper Sensors for Composite Materials (복합재료용 흑연/종이 센서의 최적제조조건 및 감지능 평가 연구)

  • Park, Ha-Seung;Shin, Pyeong-Su;Kim, Jong-Hyun;Baek, Yeong-Min;Park, Joung-Man
    • Composites Research
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    • v.31 no.2
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    • pp.51-56
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    • 2018
  • A new study was carried out to utilize a pencil drawing paper sensor (PDPS), which drew a line using a pencil on the paper, as a sensor. The sensing effect on 3 different papers based on the properties of PDPS was compared. The specimens were prepared by drawing 4B pencils on plain (A4), Hwasun, and Han papers. The silver paste was used to give good electrical contacts of the copper wires and the pencil drawn line. The chemical structures of 3 papers for PDPS by FT-IR spectrum analysis were similar and the comparative compact states of each paper were observed by optical microscope. From statistical evaluation of tensile strength using 3 papers, plain paper was chosen to be best for the PDPD. The optimum drawing number of PDPD was determined by changing the thickness of the paper with the drawing number. Electrical resistance (ER) with graphite on 3 different papers were compared. The changes in compression was observed through cyclic compressive test of composite materials, it was possible to predict the degree of strain sensing under compressive test. It leads to expectation of properties.

A Study on the Environmental Application of Image Radar for Expanding the Use of Next Generation Medium Satellite 5 (차세대중형위성 5호 활용 확대를 위한 영상레이더의 환경분야 활용 방안 연구)

  • Han, Hyeon-gyeong;Lee, Moungjin
    • Korean Journal of Remote Sensing
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    • v.35 no.6_3
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    • pp.1251-1260
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    • 2019
  • Existing environmental spatial information, which has been concentrated on spatial resolution, has limitations in solving realistic environmental problems that must be accompanied by physical and chemical characterization. Accordingly, there is a need for an image radar capable of identifying physical characteristics of an object regardless of weather conditions, day and night, and sunlight. Image radar is used in various fields in the United States and Europe. The next generation of medium-sized satellite No. 5 in Korea, which is under development with the aim of monitoring water disasters, is also looking for ways to expand the scope to various applications based on the existing application range. To this end, we analyzed domestic and international papers (100 works) using image radar, and reviewed KEI 2016 report, domestic papers, and foreign papers. Based on this, various environmental issues were summarized and the effects of when the image radar was used were analyzed and land cover was selected as an environmental issue. In the future, we will embody the technology to improve the accuracy of the land cover map, which is the environmental issue selected in this study, and build the foundation system for the stable use of the land cover map.

A Study on Corrosion Properties of Reinforced Concrete Structures in Subsurface Environment (지중 환경하에서의 철근콘크리트 구조물의 부식 특성 연구)

  • Kwon, Ki-jung;Jung, Haeryong;Park, Joo-Wan
    • The Journal of Engineering Geology
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    • v.26 no.1
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    • pp.79-85
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    • 2016
  • A concrete silo plays an important role in subsurface low- and intermediate-level waste facilities (LILW) by limiting the release of radionuclides from the silo geosphere. However, due to several physical and chemical processes the performance of the concrete structure decreases over time and consequently the concrete loses its effectiveness as a barrier against groundwater inflow and the release of radionuclides. Although a number of processes are responsible for degradation of the silo concrete, it is determined that the main cause is corrosion of the reinforcing steel. Therefore, the time it takes for the silo concrete to fail is calculated based on two factors: the initiation time of corrosion, defined as the time it takes for chloride ions to penetrate through the concrete cover, and the propagation time of corrosion. This paper aims to estimate the time taken for concrete to fail in a LILW disposal facility. Based on the United States Department of Energy (DOE) approach, which indicates that concrete fails completely once 50% of the volume of the reinforcing steel corrodes, the corrosion propagation time is calculated to be 640 years, which is the time it takes for corrosion to penetrate 0.640 cm into the reinforcing steel. In addition to the corrosion propagation time, a diffusion equation is used to calculate the initiation time of corrosion, yielding a time of 1284 years, which post-dates the closure time of the LILW disposal facility if we also consider the 640 years of corrosion propagation. The electrochemical conditions of the passive rebar surface were modified using an acceleration method. This is a useful approach because it can reduce the test time significantly by accelerating the transport of chlorides. Using instrumental analysis, the physicochemical properties of corrosion products were determined, thereby confirming that corrosion occurred, although we did not observe significant cracks in, or expansion of, the concrete. These results are consistent with those of Smartet al., 2006 who reported that corrosion products are easily compressed, meaning that cracks cannot be discerned by eye. Therefore, it is worth noting that rebar corrosion does not strongly influence the hydraulic conductivity of the concrete.