The effect ofgas sintering atmosphere on the carbon content and mechanical properties during the metal injection molding process of carbonyl iron-nickel powder was studied. The carbon content of the specimen after debinding in the pureatmosphere appeared 0.78 wt%. After showing the maximum value of 1.48 wt.% in the debinding atmosphere of 10%gas mixture, the carbon content of the debinded specimen decreased gradually with increasing thecontent in thegas mixture. The carbon contents of the sintered specimen were 0.46~0.63wt% in Na gas atmosphere, while they appeared extremely low above 40%gas atmosphere. The relative sintered density increased abruptly from 88~90% to 93~96% with the addition of Ni, while the density nearly unchanged above 2% Ni addition. The sintered density increased with increasing the fraction ofgas mixture. Tensile strength and hardness increased, and elongation decreased with increasing carbon and Ni content. In spite of high carbon content of 0.63 wt%, the superior elongation value of 10% was shown.

To examine the critical effect of oxygen concentration on embryonic development, in vitro fertilized embryos were cultured in media(TCM199 vs. SOF) supplemented sera(1O% FCS vs. 10% HS) with and without bovine oviduct epithelial cells under two gas atmosphere (5% in air vs. 5% , 5% , 90% ). Oocytes, obtained from abattoir ovaries, were matured in EGF containing TCM199 medium co-cultured with BOEC for 24 hours, followed by exposure to frozen-thawed, heparin4reated spermatozoa in TALP for 30 hours. And then early embryos(1~2 cell) were cultured in both TCM199 and SOF supplemented with 10% FCS or 10% RS under 5% in air or 5% COi, 5% , 90% . Development to morulae and blastocysts was recorded on days 7, after the start of in vitro fertilization. The developmental rates of in vitro fertilized embryos to morulae and blastocysts cultured in SOF with BOEC under 5% , 5% , 90% (24.4%) were significantly(p<0.05) higher than cultured in SOF with BOEC under 5% in air(14.1%) at seven days after in vitro fertilization. When early bovine embryos were cultured in TCM 199 and SOF under two different gas atmosphere, there were no significant differences in the developmental rates to morulae and blastocysts between supplements of 10% FCS and 10% HS. The rates of development to morulae and blastocysts were significantly(p<0.01) higher in TCM 199 with BOEC(24.7%) than TCM199 without BOEC(10.9%) under 5% in air, otherwise SOF without BOEC(36.4%) were significantly (p<0.05) higher than in SOF with BOEC (24.4%) under 5% , 5% , 90% . In summary, these experiments have proved that the culture system in SOF supplemented 10% ES is effective on in vitro development of early bovine embryos under 5% , 5% , 90% . In addition, it is effective to development of bovine embryos that TCM 199 should be co-cultured with BOEC and SOF should be cultured without somatic cells under two different gas atmosphere.

도마도 과실의 감압저장에 관한 연구의 일환으로 도마도 과실의 추숙, 노화 현상을 효소적인 면에서 관찰하고자, 퍼옥시다제의 활성 변화, 동위효소의 유무, 그리고, 이에 따른 과실내의 저장물질의 변화를 조사한 결과는 다음과 같다. 도마도 퍼옥시다제의 활성은 가용성구분, 세포벽구분, 미토콘드리아구분, 리보조옴구분의 순으로 강하게 나타났으며, 그 중 가용성과 세포벽구분의 활성이 95% 이상을 차지하고 있었다. 도마도의 추숙, 노화에 따라 퍼옥시다제의 활성은 감소하였으며 상온저장()에 비해, 저온저장()이 전반적으로 활성이 높았으며, 그 감소 경향은 유사하였다. 상압에 비해 감압구의 활성이 높았으며, 감압구 중에서도 380Torr.구가 570Torr.구에 비해 높은 활성을 보였다. 저장중 가용성(soluble), 가용화성(Solubilized), 퍼옥시다제의 전기영동 패턴(electrophoresis pattern)의 변화를 관찰한 바 3 - 4 종의 동위효소(isoenzyme)가 관찰되었으며 저장중 전기영동상의 변화가 인정되었다. 감압에 따른 저장중 일반성분의 변화는, 저온구와 상온구에 있어서, 온도에 의한 영향이 전반적으로 많이 나타나서 상온구 보다 저온구가 저장효과가 좋은 것으로 나타났고, 압력에 의한 영향도 다소간 나타내어 570Torr.구보다 380Torr.구의 저장 효과가 좋았으며, 이상의 두가지 사실을 종합해 볼때, 저온 380Torr.구가 저장효과가 가장 좋은 것으로 나타났다. 가용성 퍼옥시다제는 밴드B가 저장초기에 있었으나 저장 6일 경에 소실되었으며 밴드A는 가용화시킨 퍼옥시다제의 경우와 거의 같은 경향이었으며, 밴드는 저장시일이 경과할수록 전반적으로 약간 모여드는 경향이었다.

In this study, we analyzed seasonal variations in carbon dioxide fluxes, concentrations, and soil temperatures over three years in unvegetated tidal flats in the Beolgyo area. We also investigated the correlations between carbon dioxide fluxes and influencing factors. The average carbon dioxide flux was positive in summer and autumn but negative in winter and spring. A positive correlation was observed between carbon dioxide flux and soil temperature in spring whereas a negative correlation was noted in summer. In summer and autumn, as the soil temperature increased, the carbon dioxide flux decreased. In contrast, in spring and winter, as the soil temperature decreased, the carbon dioxide flux increased. Overall, this study reveals the significant influence of soil temperatures on carbon dioxide fluxes between the surface layer of the tidal flat and atmosphere.

The effect of coupled data assimilation (DA) on the meteorological prediction in the west coastal region of Korea was evaluated using a coupled atmosphere-ocean model (e.g., COAWST) in the spring (March 17􎂡26) of 2019. We performed two sets of simulation experiments: (1) with the coupled DA (i.e., COAWST_DA) and (2) without the coupled DA (i.e., COAWST_BASE). Overall, compared with the COAWST_BASE simulation, the COAWST_DA simulation showed good agreement in the spatial and temporal variations of meteorological variables (sea surface temperature, air temperature, wind speed, and relative humidity) with those of the observations. In particular, the effect of the coupled DA on wind speed was greatly improved. This might be primarily due to the prediction improvement of the sea surface temperature resulting from the coupled DA in the study area. In addition, the improvement of meteorological prediction in COAWST_DA simulation was also confirmed by the comparative analysis between SST and other meteorological variables (sea surface wind speed and pressure variation).

심리 교육은 어린이 교육 체계를 촉진하는 중요 내용일 뿐만 아니라 어린이의 건강한 성장을 보장하는 중요한 기초이다. 어린이 심리 교육에서 어린이의 성장과 발전을 위해 좋은 심리적 분위기를 형성하는 것은 심리 교육을 효과적으로 만드는 중요한 방법이다. 따라서 어린이 교육에서 좋은 심리적 분위기를 어떻게 효과적으로 구축할 것인지를 탐구하는 것은 현재 어린이 교육 발전에서 중시해야 하는 핵심 문제인 것이다. 따라서 본 연구는 좋은 어린이 교육의 심리적 분위기를 어떻게 구축할 것인지에 대해 몇 가지 의견을 제시하고, 이를 통해 어린이 교육 발전의 촉진 역할을 하고자 한다.

The ionization degree of hydrogen is crucial in the physics of the plasma in the solar chromosphere. It specifically limits the range of plasma temperatures that can be determined from the Hα line. Given that the chromosphere greatly deviates from the local thermodynamic equilibrium (LTE) condition, precise determinations of hydrogen ionization require the solving of the full set of non-LTE radiative transfer equations throughout the atmosphere, which is usually a formidable task. In many cases, it is still necessary to obtain a quick estimate of hydrogen ionization without having to solve for the non-LTE radiative transfer. Here, we present a simple method to meet this need. We adopt the assumption that the photoionizing radiation field changes little over time, even if physical conditions change locally. With this assumption, the photoionization rate can be obtained from a published atmosphere model and can be used to determine the degree of hydrogen ionization when the temperature and electron density are specified. The application of our method indicates that in the chromospheric environment, plasma features contain more than 10% neutral hydrogen at temperatures lower than 17,000 K but less than 1% neutral hydrogen at temperatures higher than 23,000 K, implying that the hydrogen temperature determined from the Hα line is physically plausible if it is lower than 20,000 K, but may not be real, if it is higher than 25,000 K. We conclude that our method can be readily exploited to obtain a quick estimate of hydrogen ionization in plasma features in the solar chromosphere.

The purpose of this experimental study is to investigate performance for atmosphere purification of concrete sidewalk block using high performance Nano TiO2 Carrier. As a result, concrete sidewalk block using high performance Nano TiO2 Carrier was confirmed to be superior than commercial TiO2 concrete sidewalk block to atmosphere purification.

The effects of combination treatment with sulfur dioxide generating pad (SO2 pad) and modified atmosphere packaging (MAP) on grape quality were examined under simulated exporting condition and actual export to Los Angeles, USA. The ‘Campbell Early’ grape harvested in Hwaseong, Gyeonggi was precooled at 0°C, selected and packaged at 10°C, and stored at 0°C for 30 days. The treatment was as follows: general export packaging (control), only SO2 pad, combination of SO2 pad and MAP (perforated polyethylene film, SO2 pad+MA). In case of control and only SO2 pad under simulated exporting condition, the grape quality changes with storage time were decrease in hardness and brush length, increase in stem browning, and increased in shattering rate. The treatment of SO2 pad+MA was the most effective in preserving the grape quality since SO2 concentration inside the package remained around 2.9 ppm by MA film. Grape exports from harvest to local distribution of the USA took 30 days, and only SO2 pad+MA package showed no fungus, maintained brush length and rachis color, and was lowest at 4.0% of shattering rate since the concentration of SO2 in the package was about 4.0 ppm. As a result, it was considered that the combination of SO2 pad and MA was the most effective way to maintain freshness of grape during long-term marine transportation and extend the shelf-life in exporting countries.

We have studied the technology to extend the storage period of ‘Seolhyang’ strawberries using modified atmosphere package (MAP) and ethyl pyruvate (EP) treatment for domestic distribution and export. The selected ripe strawberries harvested on December 28, 2016 at the Sancheong farmhouse were transported to the laboratory for 2 h and tested. After a day’s precooling at 4℃, the strawberries were divided into seven experimental groups. These groups were control, active MAP using low density polyethylene (LDPE), active MAP using polyamide (PA), active MAP using PA with EP treatment, passive MAP using LDPE, passive MAP using PA and passive MAP using PA with EP treatment. Quality analysis was carried out every 4 days during the storage period of 16 days. During the storage period of 16 days, MAP decreased from 3.5% to less than 1.1% in weight loss ratio compared with control, and decreased from 36% to less than 7% in fungal incidence. In the case of fungi in the EP treatment group, hyphae did not grow on the outside of the strawberry but grew to the inside. This tendency was similar to that in the low oxygen and high carbon dioxide environment of the MAP, the mycelium of the fungus did not grow outside of the strawberry. Fungi are the biggest problem in the distribution and export of strawberries, and these results suggest that MAP alone could inhibit mold and increase shelf life.

‘액체근대 교육’은 우리들에게 주어진 시대적 조건과 환경에 지나칠 정도로 적응을 강 요함에 따라 빠른 가속도의 흐름에 휩쓸리며 ‘전망’과 ‘성찰’이 매몰되고 있다. 이러할 때 교육은 활기찬 생명력이 소진되는 창조성의 결여와 노화와 죽음의 징표인 피로사회와 피로교육으로 전락하고 있다. 이러한 문제의식에서 이 논문은 화려한 전시가치로서 우 선선취경쟁의 흐름에 매몰된 흐름으로부터 내러티브의 교육으로 전회하고자 한다. 내러 티브 교육은 학습자에게 과거의 기억이 현재로 환기되는 과정에서 지속적으로 새롭게 발견되고 재해석되며 미래의 전망이 현실을 충일하게 하는 지평을 품고 있다. 내러티브 교육은 마치 놀이처럼 학습자에게 기억환기를 촉발시키는 ‘피크노랩시스의 창조성’에 기 반을 두고 있다. 따라서 내러티브 지평에서 교육 세 주체는 내면세계의 거주에서 ‘순례 의 교육 분위기’를 시너지적 협력으로 새롭게 조형할 수 있다.

Extreme tropospheric anomalies such as typhoons or regional torrential rain can degrade positioning accuracy of the GPS signal. It becomes one of the main error terms affecting high-precision positioning solutions in network RTK. This paper proposed a detection algorithm to be used during atmospheric anomalies in order to detect the tropospheric irregularities that can degrade the quality of correction data due to network errors caused by inhomogeneous atmospheric conditions between multi-reference stations. It uses an atmospheric grid that consists of four meteorological stations and estimates the troposphere zenith total delay difference at a low performance point in an atmospheric grid. AWS (automatic weather station) meteorological data can be applied to the proposed tropospheric anomaly detection algorithm when there are different atmospheric conditions between the stations. The concept of probability density distribution of the delta troposphere slant delay was proposed for the threshold determination.

This study was carried out to investigate the effect of modified-atmosphere packaging (MAP) on the quality change of “Tabor” tomatoes during long-term exportation periods. Hydroponics tomatoes were harvested at the turning stage, sorted, and box packed and then packaged in nylon film with a pallet. The packaged pallet was filled with a gas composition (5% O2, 1% CO2, and 94% N2) and stored at 10℃ for three weeks. The quality changes in weight loss, firmness, color, acidity, soluble solids, and microorganism growth were measured every 7 day interval. During the initial storage, the pallet-scale MAP showed slightly higher weight loss and firmness changes when compared to the conventional pallet. The total color change (ΔE) during ripening was delayed 10% under MAP storage. Acidity, soluble solids and phenolic compound contents decreased with increases in storage time regardless of the storage method; however, the quality changes of tomatoes were delayed in the MAP pallet. Furthermore, the decay rate of the pallet-scale MAP stored for 14 days was less than that of the conventional pallet, and the number of microorganisms was approximately 30% lower in the pallet-scale MAP, showing a positive effect on marketability. These results suggested that the pallet-scale MAP of tomatoes could ensure higher quality and longer storage periods than conventional pallet storage.

We investigated two flares in the solar atmosphere that occurred on June 3, 2012 and July 6, 2012 and caused propagation of Moreton and EIT waves. In the June 3 event, we noticed a filament winking which presumably was caused by the wave propagation from the flare. An interesting feature of this event is that there was a reflection of this wave by a coronal hole located alongside the wave propagation, but not all of this wave was transmitted by the coronal hole. Using the running difference method, we calculated the speed of Moreton and EIT waves and we found values of 926 km/s before the reflection and 276 km/s after the reflection (Moreton wave) and 1,127 km/s before the reflection and 46 km/s after the reflection (EIT wave). In the July 6 event, this phenomenon was accompanied by type II and type III solar radio bursts, and we also performed a running difference analysis to find the speed of the Moreton wave, obtaining a value of 988 km/s. The speed derived from the analysis of the solar radio burst was 1,200 km/s, and we assume that this difference was caused by the different nature of the motions in these phenomena, where the solar radio burst was caused by the propagating particles, not waves.