• Title/Summary/Keyword: RATE

Search Result 109,591, Processing Time 0.114 seconds

A Study on the Tendency of Planting Design of Designer's Gardens in the Suncheon Bay National Garden (순천만국가정원 내 작가 정원 식재 경향 연구)

  • Jung, Bom-Bee;Choi, Jung-Mean
    • Journal of the Korean Institute of Landscape Architecture
    • /
    • v.49 no.1
    • /
    • pp.70-82
    • /
    • 2021
  • The purpose of this study is to reveal the tendency of planting design through the analysis of the planting of designer's gardens in the Suncheon Bay National Garden and to derive implications for future garden planting designs. The results of the study are as follows: First, the results of the study show that the practice of tree-based planting is still valid. Large growing trees such as 'Pinus densiflrora', 'Celtis sinensis', 'Zelkova serrata', 'Machilus thunbergii', 'Pinus strobus' overwhelmed the size of the designer's garden(150 to 390㎡). Second, the selection of trees tended to be made considering the designer's intention and the decorative effects rather than by considering the physiological and ecological conditions of the site. Third, among the herbaceous, the rate of the planting of perennials was high. Fourth, the flowering period of planted herbaceous was the most common in summer, followed by spring, fall, and winter. Fifth, the frequency color of the planted herbaceous was the most common in summer, followed by spring, fall, and winter. Fifth, in terms of flower color frequency, the most common was the yellow-series, followed by red-series, blue-series Sixth, average height herbaceous plants(20~60cm) were planted the most(47.4%). Seventh, structural plants that determined the garden's framework depended on trees, and the focal plants mainly utilized were evergreen trees, and the midrange plants were the planted herbaceous plants. The implications derived from the above findings are as follows: First, to ensure the garden's quality and sustainability, the selection of trees should be carefully considered, not considering only the artist's intention but also taking into account the physical and ecological conditions. Second, herbaceous plants can be used in various ways― the garden's focal plants, midrange plants, and ground covers, so more active herbaceous planting needs to be considered. Third, in consideration of the winter landscape, herbaceous planting using characteristics, such as fruits and stems, as well as flower colors should be considered. Fourth, blue and black color herbaceous plants have a noticeable effect even in a small amount, so it is necessary to plant them actively. Fifth, for the design of herbaceous planting, where the individual property of plants can be expressed, the design method should be considered.

Performance of a Molten Carbonate Fuel Cell With Direct Internal Reforming of Methanol (메탄올 내부개질형 용융탄산염 연료전지의 성능)

  • Ha, Myeong Ju;Yoon, Sung Pil;Han, Jonghee;Lim, Tae-Hoon;Kim, Woo Sik;Nam, Suk Woo
    • Clean Technology
    • /
    • v.26 no.4
    • /
    • pp.329-335
    • /
    • 2020
  • Methanol synthesized from renewable hydrogen and captured CO2 has recently attracted great interest as a sustainable energy carrier for large-scale renewable energy storage. In this study, molten carbonate fuel cell's performance was investigated with the direct conversion of methanol into syngas inside the anode chamber of the cell. The internal reforming of methanol may significantly improve system efficiency since the heat generated from the electrochemical reaction can be used directly for the endothermic reforming reaction. The porous Ni-10 wt%Cr anode was sufficient for the methanol steam reforming reaction under the fuel cell operating condition. The direct supply of methanol into the anode chamber resulted in somewhat lower cell performance, especially at high current density. Recycling of the product gas into the anode gas inlet significantly improved the cell performance. The analysis based on material balance revealed that, with increasing current density and gas recycling ratio, the methanol steam reforming reaction rate likewise increased. A methanol conversion more significant than 90% was achieved with gas recycling. The results showed the feasibility of electricity and syngas co-production using the molten carbonate fuel cell. Further research is needed to optimize the fuel cell operating conditions for simultaneous production of electricity and syngas, considering both material and energy balances in the fuel cell.

Effect of Freshwater Discharge from a Water Reservoir on the Flow Circulation in the Semi-Closed Harbor (유수지로부터의 담수 방류가 항 내 해수순환에 미치는 영향)

  • Choi, Jae Yoon;Kim, Jong Wook;Lee, Hye Min;Yoon, Byung Il;Woo, Seung-Buhm
    • Journal of Korean Society of Coastal and Ocean Engineers
    • /
    • v.33 no.1
    • /
    • pp.1-12
    • /
    • 2021
  • To investigate the effect of freshwater discharge on the seawater circulation in the semi-closed harbor, a 3-D hydrodynamic model was applied to the International Ferry Terminal (IFT). The model run is conducted for 45 days (from May 15 to June 30, 2020), and the reproducibility of the model for time-spatial variability of current velocity and salinity was verified by comparison with model results and observation data. There are two sources of freshwater towards inside of the IFT: Han River and water reservoir located in the eastern part of IFT. In residual current velocity results, the two-layer circulation (the seaward flow near surface and the landward flow near bottom)derived from the horizontal salinity gradient in only considering the discharge from a Han River is more developed than that considering both the Han River and water reservoir. This suggests that the impact of freshwater from the reservoir is greater in the IFT areas than that from a Han River. Additionally, the two-layer circulation is stronger in the IFT located in southern part than Incheon South Port located in northern part. This process is formed by the interaction between tidal current propagating into the port and freshwater discharge from a water reservoir, and flow with a low salinity (near 0 psu) is delivered into the IFT. This low salinity distribution reinforces the horizontal stratification in front of the IFT, and maintains a two-layer circulation. Therefore, local sources of freshwater input are considered to estimate for mass transport process associated with the seawater circulation within the harbor and It is necessary to perform a numerical model according to the real-time freshwater flow rate discharged.

A Study on Investors Determinants Addressed by Startup Entrepreneurs : In the Center of Startups in Water Industry (창업기업관점에서 바라본 투자자의 투자결정요인에 관한 연구 : 물산업 창업기업을 중심으로)

  • Park, Dong Il;Yang, Young Seok;Kim, Myung Seuk
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
    • /
    • v.16 no.1
    • /
    • pp.1-19
    • /
    • 2021
  • The purpose of this research is to improve the investment success rate for startups in the water industry for the development of the entrepreneurial environment of the Korean water industry. In this research, we identified investment determinants through prior research and stratified them, and then surveyed the investor group at the beginning of the start-up using the FGI method, and determined the order of the investment determinants of investors. At the same time, we classified 41 start-ups related to the water industry into two groups: the group that received investment and the group that did not in the early stages of the start-up. Then we investigated the understanding of the investor's investment determinants, ranked them, and compared them by using the AHP technique. Through this, this research proposes five implications. First, it is important for start-ups in the early stages to receive seed investment to revitalize investment for startups in the water industry. For this, startups need to understand investors and prepare to attract investment with the perspective of angel investors rather than the perspective of VC investors. Second, Start-ups in the water sector should consider that the characteristics of the founder are important in order to receive seed investment, and also need to define their business at the industry and market level, and provide relevant rationale to meet the expectations of investors who value industry expertise and experience, and to increase the possibility of seed investment, which is important in the early stages of a startup. Third, institutions, such as K-water(Korea Water Resources Corporation), that support water industry startups need to conduct open innovation business opportunities discovery programs linked to startups so that startups currently participating in the startup support program could have business opportunities from the business infrastructure of platform-forming companies in the water industry. In particular, such institutions should help founders develop their industrial expertise and careers by supporting this type of start-up preparation process through the participation of in-house venture founders. Fourth, when K-water uses the government start-up support fund to discover and foster founders, it should increase initial contact with seed investors, conduct more thorough verification of business plans, and develop programs that use government start-up support funds to prepare a business suitable for seed angel investors. Fifth, K-water should support seed by connecting funds for initial investment among funds operated by itself. It is also necessary to develop a program that links the company receiving the seed investment with VC investment, not angel investment in cooperation with the VC fund operation entity participating as an LP so that companies that have attracted seed investment could attract follow-up VC investment.

Numerical analysis of morphological changes by opening gates of Sejong Weir (보 개방에 의한 하도의 지형변화 과정 수치모의 분석(세종보를 중심으로))

  • Jang, Chang-Lae;Baek, Tae Hyo;Kang, Taeun;Ock, Giyoung
    • Journal of Korea Water Resources Association
    • /
    • v.54 no.8
    • /
    • pp.629-641
    • /
    • 2021
  • In this study, a two-dimensional numerical model (Nays2DH) was applied to analyze the process of morphological changes in the river channel bed depending on the changes in the amount of flooding after fully opening the Sejong weir, which was constructed upstream of the Geum River. For this, numerical simulations were performed by assuming the flow conditions, such as a non-uniform flow (NF), unsteady flows (single flood event, SF), and a continuous flood event (CF). Here, in the cases of the SF and CF, the normalized hydrograph was calculated from real flood events, and then the hydrograph was reconfigured by the peak flow discharge according to the scenario, and then it was employed as the flow discharge at the upstream boundary condition. In this study, to quantitatively evaluate the morphological changes, we analyzed the time changes in the bed deformation the bed relief index (BRI), and we compared the aerial photographs of the study area and the numerical simulation results. As simulation results of the NF, when the steady flow discharge increases, the ratio of lower width to depth decreases and the speed of bar migration increases. The BRI initially increases, but the amount of change decreased with time. In addition, when the steady flow discharge increases, the BRI increased. In the case of SF, the speed of bar migration decreased with the change of the flow discharge. In terms of the morphological response to the peak flood discharge, the time lag also indicated. In other words, in the SF, the change of channel bed indicates a phase lag with respect to the hydraulic condition. In the result of numerical simulation of CF, the speed of bar migration depending on the peak flood discharges decreased exponentially despite the repeated flood occurrences. In addition, as in the result of SF, the phase lag indicated, and the speed of bar migration decreased exponentially. The BRI increased with time changes, but the rate of increase in the BRI was modest despite the continuous peak flooding. Through this study, the morphological changes based on the hydrological characteristics of the river were analyzed numerically, and the methodology suggested that a quantitative prediction for the river bed change according to the flow characteristic can be applied to the field.

Change of dietary habits and the use of home meal replacement and delivered foods due to COVID-19 among college students in Chungcheong province, Korea (충청지역 일부 대학생의 코로나-19 이후 식생활 변화, 가정간편식과 배달음식 이용 실태)

  • Kim, Mi-Hyun;Yeon, Jee-Young
    • Journal of Nutrition and Health
    • /
    • v.54 no.4
    • /
    • pp.383-397
    • /
    • 2021
  • Purpose: The purpose of this study was to evaluate the change in the use of home meal replacement (HMR) and delivered foods and food habits of college students due to coronavirus disease 2019 (COVID-19). Methods: A survey was conducted on 460 male and female college students in Chungcheong province in December 2020. Results: The methods of participation in classes in the 2nd semester of 2020 were 40.2% for '100% non-face-to-face' and 40.4% for 'more than 70.0% of non-face-to-face classes'. 52.8% of the subjects responded that their physical activity had decreased, while 36.1% of the subjects responded that their body weight had increased over the past 6 months. Regarding the use of HMR, 62.7% of the male students and 69.6% of the female students responded with '1-2 times a week or less' before the outbreak of COVID-19. After the outbreak, 57.4% of males and 46.7% of females responded with '3-4 times a week or more' (p < 0.05, p < 0.001). As for the use of delivered food, 58.3% of the females responded with '2-3 times a month or less' before the outbreak, whereas the rate of responding with '1 or more times a week' after the outbreak was 64.6% (p < 0.001). Negative changes in food habits caused by COVID-19 were in the order of irregular meals (56.7%), increased intake of delivered food (42.2%), increased intake of snacks (33.3%), and increased intake of processed foods such as HMR (30.4%). Conclusion: As mentioned above, many college students had non-face-to-face classes due to COVID-19. During this period, they experienced decreased physical activity, weight gain, and undesirable eating habits such as irregular meal time, and increased intake of processed foods, delivery foods, and snacks. Therefore, there is a high need for nutrition education and policy support for the prevention and management of health and nutrition problems of college students, which can be caused due to the COVID-19 pandemic.

A survey on the utilization practice and satisfaction of users of food and nutrition information (정보이용자의 식품영양정보 이용 실태와 만족도)

  • Kim, Inhye;Park, Min-Seo;Bae, Hyun-Joo
    • Journal of Nutrition and Health
    • /
    • v.54 no.4
    • /
    • pp.398-411
    • /
    • 2021
  • Purpose: The objective of this study was to investigate food and nutrition information utilization practices of adults aged between 20 and 30 years to provide the basic data for developing customized content. Methods: Statistical analyses were performed using the SPSS program (ver. 24.0) for the 𝛘2-test, t-test, one-way analysis of variance, and Duncan's multiple range test. Results: Of the 570 subjects surveyed, 45.4% were men, 54.6% were women, 66.3% were in their 20s, 33.7% were in their 30s, 41.4% were single-person households, and 58.6% lived with their families. On average, 14.2% of televisions (TVs), 26.0% of personal computers (PCs), and 63.7% of smartphones were used for more than three hours per day. 30.9% of respondents searched for food and nutrition information more than once a week. 70.0% of the respondents had then applied the information in real life and 54.7% of the respondents said they would share information with others. Information retrieval rate was in the order of 'restaurant (64.8%)', 'diet (57.5%)', and 'food recipes (55.7%)'. Overall satisfaction with food and nutrition information averaged 3.33 on a five-point scale. Satisfaction score was in the order of 'enough description and easy to understand (3.43)', 'matching title and content (3.35)', and 'providing new and novel information (3.22)'. Satisfaction scores were significantly higher in the group that searched for information (p < 0.001), the group that used the retrieved information in real life (p < 0.001), and the group that conveyed this information to others (p < 0.001). Conclusion: To improve information user satisfaction, it is necessary to provide customized information that fits the characteristics of information users. For this purpose, it is necessary to continuously conduct surveys and satisfaction evaluations for each target group.

Differences in Seed Vigor, Early Growth, and Secondary Compounds in Hulled and Dehulled Barley, Malting Barley, and Naked Oat Collected from Various Areas (맥종별 주산지와 재배한계지 수집종자의 활력, 초기생장 및 이차화합물 차이)

  • Park, Hyung Hwa;Kuk, Yong In
    • KOREAN JOURNAL OF CROP SCIENCE
    • /
    • v.66 no.2
    • /
    • pp.171-181
    • /
    • 2021
  • The purposes of this study were to determine how changes in temperature affect germination rates and growth of hulled and dehulled barley, malting barley, and naked oat plants, and to measure chlorophyll content, photosynthetic efficiency, and secondary compounds (total phenol, total flavonoid, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity) in plants grown at 13℃ or 25℃). Various types of barley seeds were collected from areas with ideal conditions for barley cultivation, hereinafter referred to as IA, and also from areas where barley cultivation is more difficult due to lower temperatures, hereinafter referred to as LTA. Seeds were tested for seed vigor. While there were significant differences in the electrical conductivity values between seeds collected from certain specific areas, no significant differences were evident between IA and LTA seeds, regardless of the type of barley seed. When plants were grown at 25℃, there were no significant differences in germination rates, plant height, root length and shoot fresh weight between plants originating from IA and LTA. However, there were differences in the measured parameters of some specific seeds. Similarly, under the low temperature condition of 13℃, no differences in the emergence rate, plant height, and shoot fresh weight were evident between plants originating from IA or LTA, regardless of the type of barley. However, there were differences between some specific seeds. One parameter that did vary significantly was the emergence date. Hulled barley and malting barley emerged 5 days after sowing, whereas naked oats emerged 7 days after sowing. There were no differences in the chlorophyll content and photosynthetic efficacy, regardless of the type of barley. There were no significant differences in total phenol, total flavonoid content, and DPPH radical scavenging activity between plants originating from IA and LTA, regardless of the type of barley. However, there were differences between some specific seeds. In particular, for malting barley the total flavonoid content differed in the order of Gangjin > Changwon > Haenam = Jeonju > Naju. The results indicate that crop growth, yield and content of secondary compounds in various types of barley may be affected by climate change.

Effects of Forage-Rice Cropping Systems on the Growth and Grain Quality of Early Maturing Rice Cultivars and Soil Chemical Properties in Paddy Fields in Southern Korea (사료작물-벼 작부체계가 조생종 벼의 생육과 미질 특성 및 토양의 화학적 특성에 미치는 영향)

  • Oh, Seo Young;Oh, Seong Hwan;Seo, Jong Ho;Choi, Jisu
    • KOREAN JOURNAL OF CROP SCIENCE
    • /
    • v.66 no.4
    • /
    • pp.297-306
    • /
    • 2021
  • To select rice (Oryza sativa L.) cultivars suitable for forage-rice double cropping system, the growth and grain quality of four early maturing rice cultivars (Joun, Jopyeong, Haedamssal, and Unkwang), and the chemical properties of soils were investigated under single- (fallow-rice) and forage-rice double-cropping systems in paddy fields in Miryang, southern Korea. The soil where two forage crops [Italian ryegrass (Lolium multiflorum Lam.) and oat (Avena sativa L.)] were cultivated during winter had a slightly lower pH; an increase in total nitrogen (T-N), K, Ca, and Na contents; and a slight decrease in organic matter and available P2O5 contents, compared with the soil fallowed during winter. This shows that the chemical properties of paddy soils can be improved by winter forage cropping. At the heading stage, the culm length, panicle length, panicle number, and leaf color of all cultivars, except for Haedamssal, were generally higher under double-cropping than under single-cropping. For Haedamssal, the culm length and leaf color did not differ between the cropping systems, but the panicle length was slightly shortened and its panicle number increased under double-cropping. After harvest, the yield of milled rice decreased for all cultivars except Haedamssal, but increased in Haedamssal under double-cropping. The head rice rate was slightly higher under double cropping, particularly in Jopyeong and Haedamssal, than under single-cropping. The protein content of milled rice under double cropping was higher and its amylose content was similar or slightly lower compared to those of rice under single cropping, resulting in decreased Toyo values for rice under double-cropping. The pasting temperature did not differ significantly between the cropping systems. However, Haedamssal had a low pasting temperature but a high Toyo value under double cropping, compared to the other three cultivars, suggesting that its palatability is relatively high. Furthermore, panicle number increased and milled rice yield did not decrease, even under double cropping. Therefore, Haedamssal seems to be the best cultivar for paddy-based double cropping with forage crops.

Possibility of Using Non-selective Herbicides as Desiccants for Improving Soybean Harvest Efficiency (콩 수확 효율 증진을 위한 건조제로서 비선택성 제초제의 활용 가능성)

  • Won, Ok Jae;Hong, Seo yeon;Suh, Eun Ji;Park, Jae-Sung;Lee, Hong Seok;Park, Jin-Ki;Ryu, Jong-Soo;Han, Won-Young;Han, Kil Su;Song, Duk Young
    • KOREAN JOURNAL OF CROP SCIENCE
    • /
    • v.66 no.4
    • /
    • pp.358-364
    • /
    • 2021
  • This study was conducted to select a desiccant and determine its concentration for safe usage to improve the harvesting efficiency of soybeans. Soybeans were treated with a desiccant (non-selective herbicide) before and after the maturation stage. The drying effect of the desiccant was higher at earlier treatment times than at the maturation stage, but the difference was not statistically significant. The higher efficacy might be related to the drying process of the leaves and stems, with most of the leaves and stems having already been dried by the time of hand harvesting. Desiccant treatments had no adverse effects on soybean yield, weight of 100 grains, seed quality, or seed germination rate compared with the untreated control. Pesticide residue analysis showed minimum residue concentration to be lower than the tolerance level of pesticide residues. In conclusion, it was confirmed that the desiccant was effective in drying soybean, and that there was no damage to the quality of soybean seeds. In addition to the drying effect, the dessicant treatment also facilitates the removal of weeds that interfere with the mechanical harvest and improves harvesting efficiency through the drying of the growth imbalanced individual. The desiccant treatment is expected to shorten the mechanical harvesting time by 1-2 weeks. It is thought that the selection of the proper cultivation period for other crops after soybean cultivation will be more advantageous.