Zinc injection into the coolant system of nuclear power plants is an effective method for reducing corrosion and improving performance. The effectiveness of this method is influenced by various factors such as zinc concentration and injection rate. This paper provides an overview of the factors affecting the effectiveness of zinc injection in nuclear power plants, with a focus on zinc concentration and injection rate, and discusses various research results on the effects of these factors on corrosion reduction and coolant system performance. Zinc concentration is an important factor affecting the effectiveness of zinc injection. The research results show that gradual increases in zinc concentration are more effective for coolant system stability. However, the concentration should not exceed the recommended levels as high zinc concentrations can have negative effects on the system. Injection rate is also an important factor affecting the effectiveness of this method. The research results show that gradual increases in injection rate are more effective for coolant system stability. However, excessive injection rates can have negative effects on the system such as overload of the zinc injection facility and chemical shocks within the coolant system, and therefore, should be optimized. In conclusion, zinc concentration and injection rate are important factors affecting the effectiveness of zinc injection in nuclear power plants. The optimal concentration and injection rate should be determined based on specific reactor conditions and system requirements, and efforts should be made to maximize corrosion reduction and performance improvement.

Liquid metal extraction (LME), a pyrometallurgical recycling method, is popular owing to its negligible environmental impact. LME mainly targets rare-earth permanent magnets having several rare-earth elements. Mg is used as a solvent metal for LME because of its selective and eminent reactivity with rare-earth elements in magnets. Several studies concerning the formation of Dy-Fe intermetallic compounds and their effects on LME using Mg exist. However, methods for reducing these compounds are unavailable. Fe reacts more strongly with B than with Dy; B addition can be a reducing method for Dy-Fe intermetallic compounds owing to the formation of Fe2B, which takes Fe from Dy-Fe intermetallic compounds. The FeB alloy is an adequate additive for the decomposition of Fe2B. To accomplish the former process, Mg must convey B to a permanent magnet during the decomposition of the FeB alloy. Here, the effect of Mg on the transfer of B from FeB to permanent magnet is observed through microstructural and phase analyses. Through microstructural and phase analysis, it is confirmed that FeB is converted to Fe2B upon B transfer, owing to Mg. Finally, the transfer effect of Mg is confirmed, and the possibility of reducing Dy-Fe intermetallic compounds during LME is suggested.

A 1.8 μm thick polycrystalline diamond (PCD) thin film layer is prepared on a Si(100) substrate using hot-filament chemical vapor deposition. Thereafter, its thermal conductivity is measured using the conventional laser flash analysis (LFA) method, a LaserPIT-M2 instrument, and the newly proposed light source thermal analysis (LSTA) method. The LSTA method measures the thermal conductivity of the prepared PCD thin film layer using an ultraviolet (UV) lamp with a wavelength of 395 nm as the heat source and a thermocouple installed at a specific distance. In addition, the microstructure and quality of the prepared PCD thin films are evaluated using an optical microscope, a field emission scanning electron microscope, and a micro-Raman spectroscope. The LFA, LaserPIT-M2, and LSTA determine the thermal conductivities of the PCD thin films, which are 1.7, 1430, and 213.43 W/(m·K), respectively, indicating that the LFA method and LaserPIT-M2 are prone to errors. Considering the grain size of PCD, we conclude that the LSTA method is the most reliable one for determining the thermal conductivity of the fabricated PCD thin film layers. Therefore, the proposed LSTA method presents significant potential for the accurate and reliable measurement of the thermal conductivity of PCD thin films.

We confirm whether Zr powders can restrain a rapid nitrification reaction and offer a stable oxidation reaction according to temperatures in nitrogen gas purification. A pellet-type, porous Zr getter is prepared (diameter: 10 and thickness: 3 mm) using Zr powder with an average particle size of 45 μm. While maintaining the whole system, the Zr getter reaction is confirmed with an increase in temperature from 150 to 550 oC at increments of 100 oC under 99.999 % purity nitrogen atmosphere comprising of 10 ppm of impurity. Surface color, pore size, stabilized layer, and phase change are confirmed with optical microscopy, SEM-EDS, Micro-Raman, and X-ray diffraction (XRD) according to the Zr getter temperature. The surface color of the Zr getter changes from metallic silver to dark gray as temperature increases. In the EDS results, the nitrogen component is not observed, and oxygen content increases from each surface at elevated temperatures. The Raman and XRD results show the oxidation layer as a result of 350 oC annealing. Therefore, the Zr getter can be applied as a nitrogen getter under 5-nine purity nitrogen atmosphere after appropriate oxidized pre-stabilization process to prevent rapid nitrification reaction.

The photovoltaic properties of TiO2 used for the electron transport layer in perovskite solar cells(PSCs) are compared according to the particle size. The PSCs are fabricated and prepared by employing 20 nm and 30 nm TiO2 as well as a 1:1 mixture of these particles. To analyze the microstructure and pores of each TiO2 layer, a field emission scanning electron microscope and the Brunauer–Emmett–Teller(BET) method are used. The absorbance and photovoltaic characteristic of the PSC device are examined over time using ultraviolet-visible-near-infrared spectroscopy and a solar simulator. The microstructural analysis shows that the TiO2 shape and layer thicknesses are all similar, and the BET analysis results demonstrate that the size of TiO2 and in surface pore size is very small. The results of the photovoltaic characterization show that the mean absorbance is similar, in a range of about 400-800 nm. However, the device employing 30 nm TiO2 demonstrates the highest energy conversion efficiency(ECE) of 15.07 %. Furthermore, it is determined that all the ECEs decrease over time for the devices employing the respective types of TiO2. Such differences in ECE based on particle size are due to differences in fill factor, which changes because of changes in interfacial resistance during electron movement owing to differences in the TiO2 particle size, which is explained by a one-dimensional model of the electron path through various TiO2 particles.

In Korea, the daily waste production in 2015(excluding specified waste) was 404,812 tons, of which household waste accounted for 12.7%(51,247 tons/day). Total household food and vegetable waste amounted to 1,120 tons/day; of this, 70% of was ultimately used as feed or fertilizer and 30% was buried. In this study, a drying unit was developed to enable the production of solid refuse fuel using high-moisture food waste, and its performance was examined through an experiment. Thus, a laboratory pyrolysis system with a drying capacity of 500 kg/hr was manufactured. Food wastes were collected from a company cafeteria and from Changwon City and used for experiment. The drying characteristics of the food waste were examined depending on the input temperature of the drying air. The results of the food waste drying experiment showed that the total required drying time was approximately 20 hours, and the drying speed was approximately 2.90 %/hr. The drying time was five hours longer than the research target value(15 hours per batch). However, the time was approximately 16 hours when the preheating and cooling times required for the input and output were excluded, which was close to the research target value. The drying time did not show a large difference depending on the temperature of the input drying air. Drying time was 21 hours at 155℃, and thus drying operation would be possible without the use of high-temperature air(more than 200℃) when waste heat is utilized in the future. It is thought that rather than the temperature of the input air, it is the contact area between the input air and the food waste that has a significant effect on reducing the drying time.

We propose a speedy two-step deposit process to form an Au electrode on hole transport layer(HTL) without any damage using a general thermal evaporator in a perovskite solar cell(PSC). An Au electrode with a thickness of 70 nm was prepared with one-step and two-step processes using a general thermal evaporator with a 30 cm source-substrate distance and 6.0 × 10−6 torr vacuum. The one-step process deposits the Au film with the desirable thickness through a source power of 60 and 100 W at a time. The two-step process deposits a 7 nm-thick buffer layer with source power of 60, 70, and 80 W, and then deposits the remaining film thickness at higher source power of 80, 90, and 100W. The photovoltaic properties and microstructure of these PSC devices with a glass/FTO/TiO2/perovskite/ HTL/Au electrode were measured by a solar simulator and field emission scanning electron microscope. The one-step process showed a low depo-temperature of 88.5 oC with a long deposition time of 90 minutes at 60 W. It showed a high depo-temperature of 135.4 oC with a short deposition time of 8 minutes at 100 W. All the samples showed an ECE lower than 2.8% due to damage on the HTL. The two-step process offered an ECE higher than 6.25% without HTL damage through a deposition temperature lower than 88 oC and a short deposition time within 20 minutes in general. Therefore, the proposed two-step process is favorable to produce an Au electrode layer for the PSC device with a general thermal evaporator.

Assays for detecting pregnancy-associated glycoproteins (PAGs) levels in the blood of pregnant cattle have been developed and commercialized to determine pregnancy status. This study was conducted to determine the accuracy of a PAG-based ELISA test for pregnancy detection in Hanwoo. The anticoagulated treated whole blood was sampled from 595 Hanwoo that were 28-71 d (mean 49) and 85-128 d (mean 106) after artificial insemination. At the 2nd blood collection time, a transrectal palpation test was used as the standard for pregnancy diagnosis. For PAGs and the transrectal palpation test (n=595), the sensitivity was 98.4% (pregnancy, 481/489), the specificity was 100% (open, 106/106), and the accuracy was 98.7% (pregnancy+open, 587/595). In conclusion, the rapid PAG-based ELISA pregnancy test was highly sensitive and specific for pregnancy detection in Hanwoo.

농촌사회의 소득수준 및 생활수준 향상과 더불어 농촌 공공공간 및 시설향상에 대한 요구는 지속적으로 제기되어 왔으며 이에따라 정부도 최근 다양한 방식의 농촌개발과 예산지원을 추진해오고 있다. 그러나 이러한 농촌 공공공간 및 시설의 지원 시 시설의 종류 및 입지 선정이 적절하지 않아 시설의 중복투자, 이용부족으로 인한 시설방치 등 다양한 문제점들이 제기되고 있다. 본 연구는 농촌마을에 분포하고 있는 다양한 공공공간 및 시설의 분포를 분석하고 이들에 대한 농촌마을의 유형별 중요도를 이해하는데 그 목적이 있다. 주요 연구방법으로는 100명을 대상으로 한 전문가 설문과 AHP(Analytic Hierarchy Process)를 이용하였으며 이를 통해 세 개의 농촌마을 유형 즉 거점면, 권역, 마을단위의 유형별로 주요 공공시설들간의 상대적 중요도를 분석하였다. 50개 마을을 분석한 결과 농촌마을에서 가장 일반적으로 발견되는 공공시설은 마을회관, 쉼터, 체험센터, 마을진입부, 안내시설로 나타났다. AHP는 세 단계의 비교로 이루어졌는데 첫 번째 마을유형별간의 쌍대비교에서는 거점면, 권역, 마을 순으로 중요도가 나타났다. 농촌 공공공간과 마을유형간의 쌍대비교에서는 모든 마을유형에서 기초생활시설, 문화 복지시설, 농촌관광시설, 소득시설의 순으로 중요도가 나타났다. 마을유형과 공공공간, 공공시설 등 각각의 가중치를 종 합한 중요도에서는 거점면의 경우 공동주차장의 중요성이 가장 높은 것으로 나타났고 다음으로 상수도시설, 공동화장실, 마을회관 순으로 나타났다. 권역에서는 공동주차장의 중요성이 가장 높았으며 다음으로 상수도시설, 체험센터, 마을회관 의 순으로 나타났다. 마을단위에서는 버스정류장이 가장 중요한 시설로 평가되었으며 다음으로 저수지, 하수처리장, 체 험센터의 순으로 나타났다. 본 연구는 비록 마을의 독특한 사회문화적 환경을 고려한 공공시설의 중요도 평가에는 한계를 안고 있으나 농촌마을에서의 공공시설 계획 시 마을유형의 특성을 고려한 시설의 상대적 중요도를 이해하고 이를 바탕으 로 적절한 시설을 선정하는데 도움을 줄 것으로 기대된다

Serpins are a superfamily of related protease inhibitors with common structural features and inhibitory mechanisms. However, SERPINA 14 in mammals does not have inhibitory activity against most known proteases. Rather, it may have an immunoregulatory role in mammals to prevent rejection of the fetal allograft by inhibiting lymphocyte proliferation and natural killer cell function. In the pig, SERPINA14 is involved in iron transport to the fetus by binding to and stabilizing the iron-binding protein uteroferrin (ACP5). In chickens, these very little known about serpins in chickens. Therefore, we investigated the expression patterns of serpin genes in the oviduct of adult hens and in the oviduct of 37-day-old chicks treated with an estrogen analogue, diethylstilbestrol (DES). Results indicated that SERPINB3 and SERPINB11 genes were highly expressed in oviducts of DES-treated chicks, but not in oviducts of control chicks. Both SERPINB3 and SERPINB11 transcripts were localized specifically to the gland-like areas of oviducts of DES-treated chicks. Immunohistochemical analyses confirmed that SERPINB3 and SERPINB11 proteins were present in the gland-like area and luminal epithelium of the oviducts of DES-treated chicks. Collectively, the results suggest that SERPINB3 and SERPINB11 are expressed in response to estrogens and they have distinct functions related to development and differentiation of the mature oviduct in hens.

The occurrence and rapid range expansion of a fulgorid, Lycorma delicatula(White), has recently been reported in korea. It was previously known to occur in China, Japan, Vietnam and India. The first occurrence fo L. delicatula was reported in 2004 in the Cheonan. It has one generation per year and overwinters as egg masses on the bark of host trees. The number of egg per egg mass was 32.69±6.49. The cumulative ratio of hatchability at different temperature was the highest at 25℃ and the lowest at 10, 30℃. The egg hatchability was investigated in different regions in Chung-buk. Since L. delicatula eggs has been stored in -20±1, 0±1, 5±1℃ conditions for 1 ∼60 days, the cumulative ratio of hatchability was 2% stored in -20±1℃ for 3days, But hatchability was 52, 48% stored in 0±1℃ for 3, 14days and 82, 68% stored in 5±1℃ for 3, 14days. And hatchability was 0% for 60days. By straight regression equation(the growth ratio/treatment degree) the growth zero degree of L. delicatula was 10.4℃. The hatchability of L. delicatula in Cheongwon-gun, Okcheon-gun, Cheongju-city where’s winter lowest temperature was over -19℃ was over 79%. But The hatchability of L. delicatula in Jincheon-gun where’s winter lowest temperature was less than -19℃(continuos two days) was 35%.

This experiment was conducted to compare forage production and grass intakes of warm season grasses for grazing horses in Jeju. The experimental field located at 450m altitude(Jeju Horse Training Center of Korea Racing Association) was divided into 3different treatment plots(3replications) without a fence between treatments, and sown by three treatments(bermudagrass, bahiagrass, bermudagrass+bahiagrass mixture). Three castrated adult horse a were kept on pasture from the 1 of October to the end of October without supplementary concentrates. 'Bahiagrass' cultivar showed the highest dry matter (DM) yield with 8,887㎏/㏊ than those in other treatments (bermudagrass 8,699, bermudagrass+bahiagrass mixture 8,385㎏/㏊). The percentage of grass intakes was higher in the treatment of bahiagrass(92%) than those in other treatments(bermudagrass+bahiagrass mixture 89, bermudagrass78%). The results indicate that the warm season grasses of bermudagrass, bahiagrass, bermudagrass+bahiagrass mixture can be used for grazing pasture of horses in the Jeju.

Chinese cabbage grown during autumn season is confronted with drought conditions for a certain period, especially during the early growth stage. In this study, we investigated the effects of drought stress on plant growth characteristics, as well as free amino acid, carotenoid, and proline in Chinese cabbage. Chinese cabbage seeds (Bulam Plus) were germinated, and all the seedlings were transplanted into plastic containers (28 ㎝ diameter × 22 ㎝ high) containing a commercial growth medium. The soil water content was measured and maintained at 10% for the drought-stressed plants and at 30% for the control plants, for three weeks. The results revealed that plant growth parameters were lower in the drought-stressed plants than in the control plants. The total free amino acid content tended to decrease in both drought-stressed and control plants with time. The total free amino acid content was found to be lower in the drought-stressed plants than in the control plants and the proline content was unaffected. Moreover, at three weeks after treatment, carotenoid content in drought stressed plants was significantly higher than that in the untreated plants. We believe that our study makes a significant contribution to the literature because the effects of drought stress on plant growth parameters, free amino acid, carotenoids, and proline accumulation in autumn growing cultivar of Chinese cabbage have not been widely studied in Korea, and our study provides valuable information in this regard, as Chinese cabbage is consumed throughout the year in Korea.

본 연구는 도시 유역의 물 순환을 개선시키기 위해 최근 활발하게 적용되고 있는 저영향개발(low impact development, LID) 시설의 설계 및 계획 매개변수를 선정하기 위한 방법을 제시하였다. 이때 Storm Water Management Model (SWMM) 모형의 LID 시설 모의 기능을 활용하여 다양한 매개변수에 대해 민감도 분석 및 다양한 시나리오를 자동으로 수행하여 비교할 수 있도록 개발된 Water Management Analysis Module(WMAM)을 이용하였다. 본 연구는 최근 도시화가 진행되고 있는 서울의 한 유역에 적용하였다. 적용 결과 LID 중 하나인 투수성포장 시설이 없는 경우와 임의로 결정된 설계 및 계획 시나리오 보다 본 방법을 통해 도출된 시나리오가 총유출량 및 첨두유량 감소와 침투량 증가에 더 좋은 효과를 보였다. 향후 경제성을 고려한 방법을 개발한다면 실무에서도 활용될 수 있을 것으로 예상된다.

Harmonized actions of ovarian estrogen (E2) and progesterone (P4) regulate cell proliferation and differentiation in the uterus with a spatiotemporal manner. Imbalance between the actions and levels of two major regulators often lead to infertility and gynecological diseases, such as endometriosis and endometrial cancer. While numerous works have shown that reduced expression and/or deletion of uterine factors associated with P4 signaling could disturb uterine physiology, local factor(s) to mediate E2 actions has not been extensively studied yet. Here we demonstrate that early growth response 1 (Egr1), a transcription factor which is rapidly induced in the uterus by E2, is required to maintain coordinated actions of E2 and P4 for uterine receptivity for embryo implantation. Given exogenous gonadotrophins to overcome LHβ deficiency in the pituitary of Egr1(－/－) mice, ovulation, fertilization and embryo development normally occurred in these mice. However, they showed complete failure of embryo implantation with reduced uterine responses to artificial decidualization stimuli. While serum levels of E2 and P4 in Egr1(－/－) mice were comparable, genes regulated by E2 and/or P4 in uterine epithelial cells (ECs) were aberrantly expressed on day 4 of pregnancy. Impaired P4 signaling along with absence of PR in ECs caused hypersensitive E2 responses shown as enhanced expression of E2-responsive genes such Muc1 and Ltf as well as reduced levels of P4-dependent genes, such as Ihh and Areg, in ECs of Egr1(－/－) mice. This is consistent with persistent proliferation in ECs and severely impaired proliferation in stromal cells (SCs) in Egr1(－/－) mice treated with E2+P4. Furthermore, primary co-culture of Egr1(－/－) ECs with Egr1(+/+) SCs and vice versa supported a notion that Egr1 itself is required for proper responses to two major regulators, E2 and P4, in both uterine cell compartments. Collectively, our results show that E2-induced Egr1 participates in P4-dependent modulation on E2 activities in the uterus by regulating a spectrum of genes essential for uterine receptivity and embryo implantation.

DGCR8 is a RNA-binding protein working with DROSHA to produce pre-microRNA in the nucleus, while DICER does not only mature microRNA but also endogenous siRNAs in the cytoplasm. Here, we have produced Dgcr8 conditional knock-out mice using progesterone receptor (PR)-Cre (Dgcr8flox/flox; PRcre/+ mice, Dgcr8d/d) and demonstrated that canonical microRNAs dependent of DROSHA-DGCR8 complex are required for uterine development as well as female fertility in mice. Adult Dgcr8d/d females did not undergo regular reproductive cycle and produce any pups when housed with fertile males, whereas administration of exogenous gonadotropins induced normal ovulation with corpus luteal formation in these mice. Ovulated oocytes from Dgcr8d/d mice had comparable fertilization potentials and were normally developed to the blastocyst after fertilization as compared to those in control Dgcr8f/f mice. Interestingly, PR-Cre-dependent Dgcr8 deletion showed aberrant infiltration of acute inflammatory immune cells to female reproductive organs only when Dgcr8d/d mice were mated with male mice. With respect to uterine development, gross morphology, histology, and weight of Dgcr8d/d uterus were similar to those of control at 3-week-old age. However, multiple uterine abnormalities were noticeable at 4-week-old age when PR expression is significantly increased, and these deformities became severe onwards. Gland formation and myometrial layers were significantly reduced, and stromal cell compartment did not expand and became atrophic during uterine development in these mice. These results were consistent with aberrantly reduced cell proliferation in stromal cell compartments of Dgcr8d/d mice. Collectively, our results suggest that DGCR8 dependent-canonical microRNAs are essential for development and physiology of the uterus with respect to morphogenesis, proper immune modulation, reproductive cycle, and steroid hormone responsiveness in mice.