• Journal of Mushroom
• /
• v.9 no.3
• /
• pp.96-100
• /
• 2011

MST247ns(Hwaseong #2) was developed by the method of Di-mon mating between monokaryotic strains derived from "Hwaseong #1" and dikaryotic strain "Suhan #1". The optimum temperature of mycelial growth was $25-30^{\circ}C$. The optimum temperature of primordia formation and fruiting body development were $8-15^{\circ}C$ and $9-14^{\circ}C$. Days of primordia formation were 4-5 days later Suhan #1. The stipes were longer than "Suhan #1". The surfaces of stipe were white and the tissues got harder and more elastic. Therefore, the management of growth environment under low temperatures was relatively easy and storability got much better.

• Aerospace Industry
• /
• v.39
• /
• pp.42-45
• /
• 1996

태양을 중심으로 그 주위를 돌고 있는 혹성은 모두 9개, 지구까지 합하면 10개라고도 하고 달을 빼고 9개라고도 한다. 사람이 달 표면에 처음으로 착륙한 것이 1969년, 그로부터 30년이 가까워오는 지금 사람은 달 이외에 금성, 화성, 목성, 토성 등 여러 혹성을 탐사하는데 성공했지만 구체적으로 사람이 착륙한 곳은 달 밖에 없다.

• Journal of Korea Foundry Society
• /
• v.29 no.3
• /
• pp.113-119
• /
• 2009

• Korean Chemical Engineering Research
• /
• v.60 no.2
• /
• pp.308-312
• /
• 2022

3D printing technology, which creates a physical object by various material deposition, has been widely used in recent years in the manufacturing field because of its advantages. Among the various printing technologies, droplet-based 3D printing technology (e.g., Polyjet^®) enables a high-resolution printing using photocurable materials such as hydrogels. Depending on the degree of light exposure, ejected photocurable droplets may have different properties (e.g., viscosity) until they collide with the substrate and it leads to the different spreading behaviors of the droplets (i.e., impact, spreading, and recoiling) during deposition on the substrate. In this study, experimental observation and analysis of the changes in hydrogel droplet viscosity and spreading behavior according to the light exposure were carried out based on high-speed image processing.

• Journal of the Korean institute of surface engineering
• /
• v.48 no.2
• /
• pp.56-61
• /
• 2015

In this study, the wear performance of manganese phosphate coating on SM45C with addition agent of Tartaric acid and Citric acid were investigated. The Surface morphology of manganese phosphate coating was examined by Scanning Electron Microscope (SEM) and Energy Dispersive X-ray spectroscopy (EDS). It is found that Mn, P, Fe, O and C. The crystal structure and thee composition was analysis and determined by using XRD. The XRD results indicated that manganese phosphate coatings are mainly composed of $(Mn,Fe)_5H_2(PO_4)_44H_2O$ and consists of a lot of close packed lump crystalline. Based on the time dependence of morphology and the weight of manganese phosphate coating, it shows that the phosphating process mainly includes three stages: corrosion of the substrate, creation and growth of phosphate crystal nucleus and thickening of manganese phosphate coating. The wear tests were performed in a ball on disc apparatus as per ASTM G-99 Standard. It was showed that the initial wear was quite high followed by low sludge.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.6 no.2
• /
• pp.203-212
• /
• 1996

Applicability of SiC coating through CVD process and PCS(polycarbosilane) impregnation for the oxidation resistance and mechanical properties of C/C composite was studied. The SiC layer coated by CVD was deposited uniformly on the C/C composite, whereas the SiC converted from PCS impregnation wetted around individual carbon fiber. The PCS-impregnated C/C composite exhibited a significant increase of bending strength in comparison with as received C/C composite. This increase in the mechanical property could be attributed to the high bonding strength between fibers due to an impregnated SiC phase. The PCS-impregnated C/C showed 25% improvement in density, 3.5 times higher MOR and 2.8 times higher oxidation resistance compared to the as-received C/C. The increments due to PCS impregnation were more effective than CVD process.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2009.05a
• /
• pp.78-83
• /
• 2009

In general, Light-hardening polymer was used UV nanoimprint technology. A light-hardening polymer was had the problem of poor hardness, durability. In order to overcome the problem of polymer, inter change optical glass. However glass is very manufacture and a lowering of standars transmittance. In order to glass recover was necessary polishing process. The process is magnetorheological fluids polishing. MR polishing has been developed as a new precision finishing technique to obtain a fine surface. Hence, Magnetorheological fluids has been used for micro polishing to get micro parts. This polishing process guarantees high polishing quality by controlling the fluid density electrically. The applied material in experiments is fused silica glass. Fused silica glass is widely used in the optical field because of high degree of purity. For MR polishing experiments, MR fluid was composed with DI-water, carbonyl iron and nano slurry ceria. The wheel speed and electric current were chosen as the variables for analyzing the characteristics of MR polishing process. Outstanding surface roughness of Ra=1.58nm was obtained on the fused silica glass specimen. And originally glass transmittance was recover on the fused silica glass.

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2016.11a
• /
• pp.168-168
• /
• 2016

최근 크로메이트 피막의 대체로서 실란 커플링제를 사용한 화성처리가 주목되고 있다. 실란 커플링제는 $R^{\prime}-(CH_2)_n-Si(OR)_3$로 나타내며 OR은 가수분해 가능한 메톡시기, 에톡시기 등의 알콕시기이다. OR기는 가수분해하여 반응성이 높은 시라놀기(-SiOH)를 생성하여 금속표면에 흡착하기 쉽다. 이후, 건조할 때 탈수 축합하여 공유결합이 가능하다. R'는 탄화수소에 한정되지 않고 성질이 다른 원소의 관능기를 나타내며 아미노(amino)기, 글리시딜(glycidyl)기, 멜캅토(melcapto)기, 비닐(vinyl)기를 들 수 있다. 실란 커플링제 가운데 아미노기를 갖는 실란 커플링제는 아연도금 강판을 포함한 다양한 금속의 내식성을 향상시킬 수 있는 화합물의 하나이다. 본 연구에서는 아미노기를 함유한 실란 커플링제에 인산 수용액을 도포하여 수세하지 않고 건조하여 피막을 형성시켰다. 또 부식거동 조사를 목적으로 아미노기를 함유한 실란 커플링제를 사용하여 초산첨가의 경우와 비교하였다.

• Journal of the Korean Society of Food Culture
• /
• v.22 no.4
• /
• pp.468-474
• /
• 2007

Physicochemical and sensory characteristics of cookies with various levels of resistant starch were investigated in this study. Dough pH of 30% substituted sample group had significantly the highest value than that of all(p<0.05). Water contents of Dough were decreased with increased levels of the resistant starch in cookie preparation. The spreadability was increased as the addition levels of the resistant starch were increased. The Hunter L and a values of 30% substituted sample group had the highest values of all(p<0.05). Results of sensory characteristics of 30% substituted sample group showed significantly the lower values in hardness and crack than those in the other groups at p<0.05. Acceptance tests of cookies with 10 and 20% substituted sample groups showed higher values in savory flavor and overall acceptability than those of others.

• Journal of Space Technology and Applications
• /
• v.3 no.3
• /
• pp.199-212
• /
• 2023

In contrast to the short-term nature of lunar missions in the past, lunar missions in new space era aim to extend the presence on the lunar surface and to use this capability for the Mars exploration. In order to realize extended human presence on the Moon, production and use of consumables and fuels required for the habitation and transportation using in-situ resources is an important prerequisite. The Global Exploration Roadmap presented by the International Space Exploration Coordination Group (ISECG), which reflects the space exploration plans of participating countries, shows the phases of progress from lunar surface exploration to Mars exploration and relates in-situ resource utilization (ISRU) capabilities to each phase. Based on the ISRU Gap Assessment Report from the ISECG, ISRU technology is categorized into in-situ propellant and consumable production, in-situ construction, in-space manufacturing, and related areas such as storage and utilization of products, power systems required for resource utilization. Among the lunar resources, leading countries have prioritized the utilization of ice water existing in the permanent shadow region near the lunar poles and the extraction of oxygen from the regolith, and are preparing to investigate the distribution of resources and ice water near the lunar south pole through unmanned landing missions. Resource utilization technologies such as producing hydrogen and oxygen from water by hydroelectrolysis and extracting oxygen from the lunar regolith are being developed and tested in relevant lunar surface analogue environments. It is also observed that each government emphasizes the use and development of the private sector capabilities for sustainable lunar surface exploration by purchasing lunar landing services and providing opportunities to participate in resource exploration and material extraction.