The purpose of this study was to evaluate the corrosion damage of large diameter metallic pipes buried in reclaimed land due to the corrosion effect by soil, and to propose a method of installing metal pipes in the reclaimed land. The results are as follow. First, the soil of the reclaimed land was gray clay, the soil specific resistance indicating soil corrosiveness was at least 120 Ω-cm, the pH was weakly acidic(5.04 to 5.60), the redox potential was at least 62 mV, the moisture content was at most 48.8%, and chlorine ions and sulfate ions were up to 4,706.1 mg/kg and 420 mg/kg. Therefore, the overall soil corrosivity score was up to 19, and the external corrosion effect seems to be very large. Second, the condition of straight part of pipes was in good condition, but most of KP joints were affected by corrosion at a severe level. The reason for this seems to be that KP joints accelerated corrosion due to stress and crevice corrosion in addition to galvanic corrosion in the same environment. Third, as a result of evaluating correlations of each item that affects the corrosion on the external part, the lower the soil resistivity and redox potential, the greater the effect on the KP joints corrosion, and the moisture content, chloride ion, and sulfate ion, the higher the value, the greater the effect on the corrosion of KP joints. In addition, among soil corrosion items, the coefficient of determination of soil resistivity with corrosion of KP joints was the highest with 0.6439~0.7672. Fourth, when installing metal pipes or other accessories because the soil of the reclaimed land is highly corrosive, it is necessary to apply a corrosion preventive method to extend the life of pipes and prevent leakage accidents caused by corrosion damage to the joint.

본 연구는 토마토 공정묘 생산 시 생장 억제를 위한 적정 brushing 소재를 구명하기 위해 수행하였다. 토마토 종자를 상업적 공정육묘용 상토가 충진된 40구 플러그 트레이에 파종하였으며, 파종 후 18일째부터 brushing 자극을 처리하였다. Brushing 소재는 연질 아크릴, 폴리프로필렌, 직조필름 소재를 이용하여 brushing 처리를 하였으며, 대조구로 무처리구와 diniconazole을 엽면살포 처리하였다. 연질 아크릴 처리에서 초장이 유의적으로 가장 짧았고, 경경은 가장 두꺼웠다. 잎의 크기는 diniconazole 처리에서 가장 낮았으나, SPAD값은 가장 높게 나타났다. 연질 아크릴 처리에서 T/R율이 가장 낮고, 왜화율과 충실도가 가장 높게 나타났다. 결과적으로, brushing 자극 처리를 위해 연질 아크릴 소재를 이용하는 것이 diniconazole 처리 보다 왜화율이 높아 도장 억제에 유리하며 묘 소질이 우수한 묘를 생산하는데 적절할 것으로 판단된다.

This study was conducted to investigate the quality of kimchi cabbages stored under a pallet unit-controlled atmosphere (PUCA), containing 2% O2 and 5% CO2, and to develop quality prediction models for cabbages stored under such conditions. Summer and winter cabbage samples were divided into PUCA-exposed groups and atmospheric airexposed control groups (in a cold storage). The control summer cabbages lost up to 8.31% of their weight, whereas the PUCA-exposed summer cabbages lost only 1.23% of their weight. Additionally, PUCA storage effectively delayed the reduction in cabbage moisture content compared with the control storage. After storage for 60 and 120 days of the summer and winter samples, respectively, the reducing sugar contents were higher in the PUCA groups than in the control groups. The linear regression analysis-derived equations for predicting the storage period, weight loss, and moisture content in the control groups, as well as those for predicting the storage period and weight loss in the PUCA groups, were appropriate according to the adjusted coefficient of determination, root mean square error, accuracy factor, and bias factor values. Therefore, this PUCA system would be useful for improving the shelf life of the postharvest summer and winter cabbages used in the commercial kimchi industry.

The aim of this study was to investigate the effects of timing of collecting date and concentration of IBA and NAA, in order to enhance initial activity and seedling quality of domestic strawberry. Strawberry cuttings were separately taken twice, in June 7 and in July 5, and IBA and NAA were treated with the concentrations of 0.025, 0.05 and 0.1% at cutting date, respectively. The seedlings were evaluated for the percentage of survival during 18 days at 6 times after tunnel cultivation. The NAA treatment was inappropriate for strawberry cutting due to the high rate of seedling mortality, regardless of the collecting date. The vitality of the seedlings was highest at IBA 0.1% in June collecting and at IBA 0.05% in July collecting. The seedlings from June collecting had a higher quantum yield at IBA 0.1% and the seedlings from July collecting at IBA 0.05%. Therefore, IBA could be more effectively applied than NAA to promote the vitality and quality with the appropriate concentration of 0.1% at June collecting and 0.05% at July collecting, respectively.

This study was conducted to determine the optimum medium and humidification period for the strawberry (Fragaria × ananassa Duch. cv. Maehyang) cutting seedling production. The cuttings were planted in coir (CO), rockwool (RW), phenolic foam (PF), and organic foam medium (OFM) with fogging treatment in 0, 3, 6, 9, or 12 days on February, 2019. And, as the field verification examination research, cuttings were planted in CO, RW, PF, and OFM, with misting treatment in 0, 6, 9, 12, or 15 days on June, 2019. In fogging treatments, rooting and survival rates of seedlings tended to increase with longer fogging periods, and rooting and survival rates were showed significantly higher in CO medium with more than 9 days of fogging periods. In misting treatments, rooting rate was significantly higher in CO and RW medium with more than 9 days of misting periods, and survival rate was significantly higher with more than 12 days of misting periods. There was no significantly difference by growth medium and humidification period in shoot and root growth. Therefore, when considering the rooting and survival rate the CO medium with 9 days of humidification period could be beneficial for the production of the ‘Maehyang’ strawberry cutting seedlings.

The purpose of this study was to establish the optimum experimental conditions by investigating the relationship between the nine experimental conditions using Taguchi technique. Through experiments, we found that the weight, thickness, and length of the sample were most affected by the angle at which the sample was installed, while the width had the largest influence on the sample's x-axis and the inner diameter. It was confirmed. Therefore, through this experiment, it was confirmed that the installation angle of the product had the greatest influence on the error occurrence of the product during 3D printer processing.

The purpose of this study was to investigate the comparison of nutrient intake and metabolic syndrome between single person households and non-single person households in elderly subjects. We analyzed data from 2,903 subjects ≥ age 65 who participated in the Korea National Health and Nutrition Examination Survey (KNHANES) 2013~2015. As a result, single-person households had lower income and economic ability, overall nutrient intake was deteriorated, and the proportion of high-carbohydrate intake was high, compared to non-single person households. After adjusting for potential confounders (sex, age, education, household income, economic activity, smoking status, alcohol consumption, walking frequency, health status, depression status, and dietary factors), the singleperson household showed a tendency of 1.22-fold higher ORs of metabolic syndrome and 1.3-fold higher ORs of hypertriglyceridemia than the non-single-person household. We suggest that the single-person household may be associated with increased prevalence of metabolic syndrome and hypertriglyceridemia in the elderly subjects.

Bismuth vanadate (BiVO4) is considered a potentially attractive candidate for the visible-light-driven photodegradation of organic pollutants. In an effort to enhance their photocatalytic activities, BiVO4 nanofibers with controlled microstructures, grain sizes, and crystallinities are successfully prepared by electrospinning followed by a precisely controlled heat treatment. The structural features, morphologies, and photo-absorption performances of the asprepared samples are systematically investigated and can be readily controlled by varying the calcination temperature. From the physicochemical analysis results of the synthesized nanofiber, it is found that the nanofiber calcines at a lower temperature, shows a smaller crystallite size, and lower crystallinity. The photocatalytic degradation of rhodamine-B (RhB) reveals that the photocatalytic activity of the BiVO4 nanofibers can be improved by a thermal treatment at a relatively low temperature because of the optimization of the conflicting characteristics, crystallinity, crystallite size, and microstructure. The photocatalytic activity of the nanofiber calcined at 350oC for the degradation of RhB under visible-light irradiation exhibits a greater photocatalytic activity than the nanofibers synthesized at 400oC and 450oC.

본 연구는 서부 민간인통제선 일대 둠벙에 서식하는 저서 성대형무척추동물 종 다양성 및 군집 구조를 규명하여 향후 보전방향을 제안하고자 하였다. 조사 결과 3문 5강 17목 59 과 192종의 저서성대형무척추동물이 출현하였다. 다른 지역의 둠벙 (61~131종), 다른 유형의 정수성 습지 (47~92종), 그리고 우포늪 등의 보호습지 (48~135종)와 비교할 때, 서부 민간인출입통제구역 일대 둠벙에서 더 다양한 분류군이 출현하는 것으로 나타났다. 환경부 지정 멸종위기야생생물 물방개, 물장군, 대모잠자리를 포함 28종의 특이종이 확인되었으며, 98곳의 조사지에 특이종이 하나 이상 분포하는 것을 확인하였다. 한편 섭식기능군 및 서식기능군 분석에서 이동성이 높은 무리의 우점이 나타난 점, 개별 조사지의 다양도와 특이종의 출현 빈도가 반드시 비례하지는 않는 점을 함께 고려할 때, 서부 민간인출입통제구역 일대 둠벙의 높은 종 다양성은 둠벙과 인근 수생태계의 연결성을 통해 유지되는 것으로 보여진다. 그러므로 서부 민통선 일대 둠벙의 생물 다양성 보전계획을 수립할 때 특별히 종 다양성이 높은 몇 개 둠벙만을 점적으로 보전하는 접근은 부적절할 수 있으리라 판단 되며, 둠벙을 포함한 수서생물의 이동성 서식지 전반의 연결성을 고려한 접근이 적절할 것으로 생각된다.

In an effort to find a way to optimize the learning condition, this study examined the effects of two types of input frequency distribution, skewed-first distribution (SFD) versus balanced distribution (BD), and two types of focus-on-form techniques, input processing (IP) versus input enhancement (IE), on the learning of English participles by Korean middle school students. A total of 91 students participated in this study, divided into five subgroups: SFD + IP, SFD + IE, BD + IP, BD + IE, and Control. The learning outcomes and the generalizability of the learned knowledge were measured through scaled judgment tasks and picture description tasks, immediately after treatment as well as one week later. The results showed that the input frequency distribution factor did not have statistically significant effects on learning and generalizability, while the degrees of explicitness of focus-on-form techniques had statistically significant effects on both. The interaction effects of the two main factors were not statistically significant. More detailed findings are presented with some pedagogical implications for Korean EFL classrooms.