• Title/Summary/Keyword: Generation Rates

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Regeneration of adventitious root from Calystegia soldanella L. in Jeju island and mass proliferation method using bioreactor system (제주지역 갯메꽃(Calystegia soldanella L.) 유래 부정근 재분화 및 생물반응기 시스템 이용 대량증식법)

  • Jong-Du Lee;Eunbi Jang;Weon-Jong Yoon;Yong-Hwan Jung
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2021.04a
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    • pp.37-37
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    • 2021
  • Calystegia soldanella L. is a perennial herbaceous halophyte belonging to the convolvulaceae family, which mainly grows in coastal sand dunes in Korea. Shoots and rhizomes are edible, and roots called 'Hyoseon Chogeun' are known to have medicinal effects such as antipyretic, sterilization, and diuretic. In addition, physiological activities of antioxidant, anti-inflammatory, antiviral, antifungal and PTP-1B (protein tyrosine phosphate-1B) inhibition have been reported. In this study, in vitro induction cell lines of C. soldanella L. collected from the coastal sand dunes in Jeju island was redifferentiated into adventitious roots that can be used as medicinal resources. Also the biomass of mass-proliferated adventitious roots using a bioreactor were evaluated. Plants of C. soldanella L. were collected from the crevice of the seashore in the coastal area of Taeheung 2-ri, Namwon-eup, Seogwipo-si. Then, it was separated into leaves, stems, rhizomes, and roots, and surface sterilized with 70% ethyl alcohol and 2% NaOCl (sodium hypochlorite). After washing with sterilized water, each organ section was cultured in Hormone-free MS medium (Murashige & Skoog Medium). As a result, the induction response rates were evaluated at 85% and 55%, respectively, in terms of callus formation and shoot generation in the rhizome segment. In the case of the adventitious roots morphological characteristics induced by single-use treatment of auxin-based plant growth regulators IBA and NAA from redifferentiated shoots were compared. Most efficient adventitious root culture method as a rooting rate, number, length, and biomass proliferation in the bioreactor system was confirmed when treated by culturing in MS salts, Sucrose 30 g·L-1, and IBA 1mg·L-1 for 4 weeks. In this study, the medium composition and culture period were confirmed using a bioreactor system to mass-proliferate adventitious roots derived from C. soldanella L. in Jeju island. Also this adventitious root line developed a new medicinal material could increase value of the bio-industry ingredient through quantitative and qualitative screening of phyto-bioactive compounds.

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Fabrication and Electrochemical Characterization of Carbon Fluoride-based Lithium-Ion Primary Batteries with Improved Rate Performance Using Oxygen Plasma (산소 플라즈마를 이용하여 율속 성능이 개선된 불화탄소 기반 리튬 일차전지의 제조 및 전기 화학적 특성)

  • Seoyeong Cheon;Naeun Ha;Chaehun Lim;Seongjae Myeong;In Woo Lee;Young-Seak Lee
    • Applied Chemistry for Engineering
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    • v.34 no.5
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    • pp.534-540
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    • 2023
  • The high-rate performance is limited by several factors, such as polarization generation, low electrical conductivity, low surface energy, and low electrolyte permeability of CFX, which is widely used as a cathode active material in the lithium primary battery. Therefore, in this study, we aimed to improve the battery performance by using carbon fluoride modified by surface treatment using oxygen plasma as a cathode for lithium primary batteries. Through XPS and XRD analysis, changes in the surface chemical characteristics and crystal structure of CFX modified by oxygen plasma treatment were analyzed, and accordingly, the electrochemical characteristics of lithium-ion primary batteries were analyzed and discussed. As a result, the highest number of semi-ionic C-F bonds were formed under the oxygen plasma treatment condition (7.5 minutes) with the lowest fluorine to carbon (F/C) ratio. In addition, the primary cell prepared under this condition using carbon fluoride as the active material of the cathode showed the highest 3 F/C(3 C rate-performance) rate-performance and maintained a relatively high capacity (550 mAh/g) even at high rates. In this study, it was possible to produce lithium primary batteries with high-rate performance by adjusting the fluorine contents of carbon fluoride and the type of carbon-fluorine bonding through oxygen plasma treatment.

A Study on the Prior Leaching and Recovery of Lithium from the Spent LiFePO4 Cathode Powder Using Strong Organic Acid (강유기산을 이용한 폐LiFePO4 양극분말로부터 리튬의 선침출에 대한 연구)

  • Dae-Weon Kim;Soo-Hyun Ban;Hee-Seon Kim;Jun-Mo Ahn
    • Clean Technology
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    • v.30 no.2
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    • pp.105-112
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    • 2024
  • Globally, the demand for electric vehicles has surged due to greenhouse gas regulations related to climate change, leading to an increase in the production of used batteries as a consequence of the battery life issue. This study aims to selectively leach and recover valuable metal lithium from the cathode material of spent LFP (LiFePO4) batteries among lithium-ion batteries. Generally, the use of inorganic acids results in the emission of toxic gases or the generation of large quantities of wastewater, causing environmental issues. To address this, research is being conducted to leach lithium using organic acids and other leaching agents. In this study, selective leaching was performed using the organic acid methane sulfonic acid (MSA, CH3SO3H). Experiments were conducted to determine the optimal conditions for selectively leaching lithium by varying the MSA concentration, pulp density, and hydrogen peroxide dosage. The results of this study showed that lithium was leached at approximately 100%, while iron and phosphorus components were leached at about 1%, verifying the leaching efficiency and the leaching rates of the main components under different variables.

A Study on Strategic Development Approaches for Cyber Seniors in the Information Security Industry

  • Seung Han Yoon;Ah Reum Kang
    • Journal of the Korea Society of Computer and Information
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    • v.29 no.4
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    • pp.73-82
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    • 2024
  • In 2017, the United Nations reported that the population aged 60 and above was increasing more rapidly than all younger age groups worldwide, projecting that by 2050, the population aged 60 and above would constitute at least 25% of the global population, excluding Africa. The world is experiencing a decline in the rate of increase in the working-age population due to global aging, and the younger generation tends to avoid difficult and challenging occupations. Although theoretically, AI equipped with artificial intelligence can replace humans in all fields, in the realm of practical information security, human judgment and expertise are absolutely essential, especially in ethical considerations. Therefore, this paper proposes a method to retrain and reintegrate IT professionals aged 50 and above who are retiring or seeking career transitions, aiming to bring them back into the industry. For this research, surveys were conducted with 21 government/public agencies representing demand and 9 security monitoring companies representing supply. Survey results indicated that both demand (90%) and supply (78%) unanimously agreed on the absolute necessity of such measures. If the results of this research are applied in the field, it could lead to the strategic development of senior information security professionals, laying the foundation for a new market in the Korean information security industry amid the era of low birth rates and longevity.

A Study on the Development of University Life Design Course for New College Students: Focusing on N University in Chungnam (대학 신입생을 위한 대학생활설계 교과목 개발 연구 : 충남소재 N대학교를 중심으로)

  • Jung In Suk;Seung Min Lee
    • The Journal of the Convergence on Culture Technology
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    • v.10 no.5
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    • pp.323-330
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    • 2024
  • He reality is that the college life culture of college students is gradually changing as we enter the AI era. In addition, in the aftermath of the MZ generation's employment difficulties and unemployment difficulties, freshmen begin to worry about their future from college entrance. Therefore, it is necessary to design a college life that can lead to employment from a careful plan for an efficient life in college. This study attempted to suggest a direction for college freshmen to find their career direction, starting with self-exploration, and helping them settle down in college life. In addition, a program was developed with a focus on understanding others and communicating human relationships toward fostering communities, starting with self-understanding. Weeks 1 to 5 were composed of getting to know each other, weeks 6 to 10 were made up of me, we, and weeks 11 to 15 were made up of our future. First, a program was developed so that you can understand yourself and plan your own career path based on this, present your own vision, and specify your future to draw a blueprint.We expect that the research results will contribute to the maturation of career attitudes of students participating in college life planning classes, smooth communication, reduction of school and department dropout rates, and encouragement of satisfaction and pride in school.

Susceptibility tests of oral antibiotics including cefixime against Escherichia coli, isolated from pediatric patients with community acquired urinary tract infections (소아 원외 요로감염 환아에서 분리된 E. coli에 대한 cefixime을 포함한 경구 항생제의 감수성 연구)

  • Lee, Soo Young;Lee, Jung Hyun;Kim, Jong Hyun;Hur, Jae Kyun;Kim, Sun Mi;Ma, Sang Hyuk;Kang, Jin Han
    • Clinical and Experimental Pediatrics
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    • v.49 no.7
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    • pp.777-783
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    • 2006
  • Purpose : Urinary tract infection(UTI) is one of the most frequent infections in children. E. coli is the most frequent etiological micropathogen in pediatric community UTI, and E. coli has developed resistance to many antibiotics, highlighting the need for regular surveys of this organism resistant patterns in the community. The aim of this study was to determine the oral antibiotic susceptibility patterns of E. coli, isolated from pediatric patients with uncomplicated community acquired UTI. Methods : E. coli isolates, obtained from pediatric patients with uncomplicated community acquired UTI between October in 2004 to September in 2005. And minimal inhibitory concentrations(MICs) of oral aminopenicillins and beta-lactamase inhibnitors(ampicillin, amoxacillin, ampicillin-sulbactam), oral cephalosporins(cefaclor, cefixime) and sulfa drug(trimethoprime-sulfamethoxazole) were performed according to the National Committee for Clinical Laboratory Standards(NCCLS) guide line. Results : Total 211 organisms were isolated from pediatric out-patients with community UTI. E. coli was the most common organism(89 percent), followed by E. fecalis, Proteus species, S. aureus, M. morganii, and P. aeruginosa. The resistant rates of aminopenicillins and beta-lactamase inhibitors, cefaclor and sulfa drug to E. coli were very high. But, the resistant rate of cefixime was markedly low, and ESBL strains were isolated with small rates. Conclusion : Our study results suggest that aminopenicillins, cefaclor and sulfa drug may not be useful as first line empirical antibiotics to treat pediatric patients with community UTI in Korea. But, 3rd generation cephalosporin such as cefixime can be used as effective second line antibiotics after primary treatment failure, also may be useful as an empirical first line antibiotic. Finally, we conclude that a continuous surveillance study to monitor susceptibility patterns of E. coli in community UTI will be needed for the standard guide lines of empirical oral antibiotic treatment.

Life Table Analysis of the Brown Planthopper, Nilaparvata lugens Stål (Hemiptera: Delphacidae) on Rice of Resistant Cultivars (벼멸구 저항성 품종벼에서 벼멸구의 생명표 분석)

  • Choi, Nak Jung;Jeong, In-Hong;Kwon, Deok Ho;Choi, Man-Young;Baik, Chai-Hun
    • Korean Journal of Environmental Biology
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    • v.35 no.4
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    • pp.526-532
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    • 2017
  • Development, survival, and reproduction of brown planthopper (BPH) Nilaparvata lugens $St{\aa}l$ (Hemiptera: Delphacidae), were studied in laboratory at $25{\pm}2^{\circ}C$, $65{\pm}5%$ RH and a 16L : 8D hours photoperiodism on five rice cultivars of: Dongjin 1ho, Chungchungbyeo, Jangseongbyeo, Chinnongbyeo and Jungmo 1045. BPH nymphs successfully survived on all rice cultivars, although survival rate was lowest on Jangseongbyeo (36.0%). Developmental time of immature stages ranged from $11.7{\pm}0.59d$ on Jungmo 1045 to $12.8{\pm}0.59d$ on Chinnongbyeo. Reproductive period and female longevity were longest on Dongjin 1ho, Chinnongbyeo and Jungmo 1045 while highest fecundity of N. lugens being observed on these three rice cultivars. Highest and lowest net reproductive rates were calculated on rice cultivars, Jungmo 1045 and Jangseongbyeo, respectively. Mean generation time was the longest on rice cultivar Dongjin 1ho. Respective descending order of intrinsic rates of population increase were on Jungmo 1045, Chinnongbyeo, Dongjin 1ho, Chungchungbyeo and Jangseongbyeo. These population parameters showed that N. lugens can successfully survive and reproduce on Chinnongbyeo and Jungmo 1045.

PRC Maritime Operational Capability and the Task for the ROK Military (중국군의 해양작전능력과 한국군의 과제)

  • Kim, Min-Seok
    • Strategy21
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    • s.33
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    • pp.65-112
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    • 2014
  • Recent trends show that the PRC has stepped aside its "army-centered approach" and placed greater emphasis on its Navy and Air Force for a wider range of operations, thereby reducing its ground force and harnessing its economic power and military technology into naval development. A quantitative growth of the PLA Navy itself is no surprise as this is not a recent phenomenon. Now is the time to pay closer attention to the level of PRC naval force's performance and the extent of its warfighting capacity in the maritime domain. It is also worth asking what China can do with its widening naval power foundation. In short, it is time to delve into several possible scenarios I which the PRC poses a real threat. With this in mind, in Section Two the paper seeks to observe the construction progress of PRC's naval power and its future prospects up to the year 2020, and categorize time frame according to its major force improvement trends. By analyzing qualitative improvements made over time, such as the scale of investment and the number of ships compared to increase in displacement (tonnage), this paper attempts to identify salient features in the construction of naval power. Chapter Three sets out performance evaluation on each type of PRC naval ships as well as capabilities of the Navy, Air Force, the Second Artillery (i.e., strategic missile forces) and satellites that could support maritime warfare. Finall, the concluding chapter estimates the PRC's maritime warfighting capability as anticipated in respective conflict scenarios, and considers its impact on the Korean Peninsula and proposes the directions ROK should steer in response. First of all, since the 1980s the PRC navy has undergone transitions as the focus of its military strategic outlook shifted from ground warfare to maritime warfare, and within 30 years of its effort to construct naval power while greatly reducing the size of its ground forces, the PRC has succeeded in building its naval power next to the U.S.'s in the world in terms of number, with acquisition of an aircraft carrier, Chinese-version of the Aegis, submarines and so on. The PRC also enjoys great potentials to qualitatively develop its forces such as indigenous aircraft carriers, next-generation strategic submarines, next-generation destroyers and so forth, which is possible because the PRC has accumulated its independent production capabilities in the process of its 30-year-long efforts. Secondly, one could argue that ROK still has its chances of coping with the PRC in naval power since, despite its continuous efforts, many estimate that the PRC naval force is roughly ten or more years behind that of superpowers such as the U.S., on areas including radar detection capability, EW capability, C4I and data-link systems, doctrines on force employment as well as tactics, and such gap cannot be easily overcome. The most probable scenarios involving the PRC in sea areas surrounding the Korean Peninsula are: first, upon the outbreak of war in the peninsula, the PRC may pursue military intervention through sea, thereby undermining efforts of the ROK-U.S. combined operations; second, ROK-PRC or PRC-Japan conflicts over maritime jurisdiction or ownership over the Senkaku/Diaoyu islands could inflict damage to ROK territorial sovereignty or economic gains. The PRC would likely attempt to resolve the conflict employing blitzkrieg tactics before U.S. forces arrive on the scene, while at the same time delaying and denying access of the incoming U.S. forces. If this proves unattainable, the PRC could take a course of action adopting "long-term attrition warfare," thus weakening its enemy's sustainability. All in all, thiss paper makes three proposals on how the ROK should respond. First, modern warfare as well as the emergent future warfare demonstrates that the center stage of battle is no longer the domestic territory, but rather further away into the sea and space. In this respect, the ROKN should take advantage of the distinct feature of battle space on the peninsula, which is surrounded by the seas, and obtain capabilities to intercept more than 50 percent of the enemy's ballistic missiles, including those of North Korea. In tandem with this capacity, employment of a large scale of UAV/F Carrier for Kill Chain operations should enhance effectiveness. This is because conditions are more favorable to defend from sea, on matters concerning accuracy rates against enemy targets, minimized threat of friendly damage, and cost effectiveness. Second, to maintain readiness for a North Korean crisis where timely deployment of US forces is not possible, the ROKN ought to obtain capabilities to hold the enemy attack at bay while deterring PRC naval intervention. It is also argued that ROKN should strengthen its power so as to protect national interests in the seas surrounding the peninsula without support from the USN, should ROK-PRC or ROK-Japan conflict arise concerning maritime jurisprudence. Third, the ROK should fortify infrastructures for independent construction of naval power and expand its R&D efforts, and for this purpose, the ROK should make the most of the advantages stemming from the ROK-U.S. alliance inducing active support from the United States. The rationale behind this argument is that while it is strategically effective to rely on alliance or jump on the bandwagon, the ultimate goal is always to acquire an independent response capability as much as possible.

Effects of Feeding Aspergillus oryzae Ferments on Performance, Intestinal Microflora, Blood Serum Components and Environmental Factors in Broiler (Aspergillus oryzae 배양물의 급여가 육계의 생산성, 장내미생물, 혈청성분 및 계사환경 요인에 미치는 영향)

  • 김상호;박수영;유동조;이상진;류경선;이동규
    • Korean Journal of Poultry Science
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    • v.30 no.3
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    • pp.151-159
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    • 2003
  • Two experiments were carried out to evaluate the effects of feeding Aspergillus oryzae(AO) ferment on performance, intestinal microflora, serum components, ammonia generation and litter dampness in broiler chicks. In experiment I, three hundred sixty, one day old broiler chicks, Abor Acres, were fed 0 and 0.1% of Aspergiilus oryzae short conidia ferment(AOS) and 0.1% of Aspergillus oryzae long conidia ferment(AOL) for five weeks. In experiment II, three hundred sixty, one day old broiler chicks, Abor Acres were fed 0, 0.1 and 0.2% of Aspergillus oryzae long conidia ferment(AOL) for five weeks. In experiment I, growth rates were not statistically different among dietary treatments. AOS and AOL showed increased tendency in weight gain and feed intake compared to those of control, whereas feed conversion was not different. Litter dampness of AOS and AOL was also tended to decrease compared to that of control, but was not significantly different. Fecal ammonia gas generation was decreased in feeding AOS and AOL, and maintained 1/2 to 3/4 compared to the control. In serum metabolites, AOS and AOL increased glucose and calcium, and decreased total protein, blood urea nitrogen and total cholesterol. In experiment II, body weight of chicks fed 0.1 and 0.2% AOL were heavier than the control(P<0.05). Feed intake of chicks fed 0.1 and 0.2% AOL also were higher than the none, but feed conversion ratio was not different among treatments. Ileal and cecal microflora showed increased tendency in lactic acid bacteria compared to those of the control. Salmonella and E. coli were decreased in ileum of chicks fed 0.1 and 0.2% AOL. In conclusion, feeding AO ferment increased growth performance and improved intestinal microflora of broiler chicks and environments of broiler house.

Studies on the Petroleum hydrocarbon-utilizing Microorganisms(Part 1) -On the Production of Protein from the Yeast-cell- (석유(탄화수소) 이용미생물에 관한 연구(제 1보) -효모세포에 의한 석유로부터 단백질 생성에 관하여-)

  • Lee, Ke-Ho;Shin, Hyun-Kyung
    • Applied Biological Chemistry
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    • v.13 no.1
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    • pp.43-50
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    • 1970
  • To study the productivity of single cell protein from the petroleum hydrocarbon utilizing yeasts, 242 soil samples, such as oil soaked soil of gas stations and garage, coal, farm soil, and sewage, from 135 places in Korea were collected. From these samples 468 yeast strains which utilize petroleum hydrocarbon as a sole organic carbon source were isolated and identified by observing the growth rates. For the identified strains optimum culture conditions were determined and analysis of cell components were performed. 1. 90.8% of petroleum hydrocarbon utilizing yeast strains were found from oil soaked soil and about 10% from coal, farm soil and sewage etc. 2. The yeast strain of the highest cell productivity was isolated from oil soaked soil and was identified as Candida curvata HY-69-19. 3. The optimum culture conditions for the selected yeast strain were found to be pH 5.0, $28^{\circ}C$ and affluent aerated state. 4. Candida curvata HY-69-19 was found to utilize favorably the heavy gas oil fractionated at above $268.9^{\circ}C$ as carbon source and urea as inorganic nitrogen source. 5. The growth curve of this strain on heavy gas oil medium showed that the yeast has a lag phase up to 18 hours and logarithmic growth phase between 24 to 42 hours. Generation time was found to be between 3.8 and 4.5 hours during the logarithmic growth phase. 6. About 300 mg dried cells per heavy gas oil was harvested under the culture conditions of adjusted pH to 5.0 at time intervals of 6 hours for 54 hours and heavy gas oil urea for shaking culture medium. 7. Chemical composition of the yeast cell was found to be 40.25%, 14.81%, 24.32% and 10.63% for crude protein, crude lipid, carbohydrate and ashes, respectively.

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