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Observational Overview of the May 2024 G5-Level Geomagnetic Storm: From Solar Eruptions to Terrestrial Consequences

  • Young-Sil Kwak;Jeong-Heon Kim;Sujin Kim;Yukinaga Miyashita;Taeyong Yang;Sung-Hong Park;Eun-Kyung Lim;Jongil Jung;Hosik Kam;Jaewook Lee;Hwanhee Lee;Ji-Hyun Yoo;Haein Lee;Ryun-Young Kwon;Jungjoon Seough;Uk-Won Nam;Woo Kyoung Lee;Junseok Hong;Jongdae Sohn;Jaeyoung Kwak;Hannah Kwak;Rok-Soon Kim;Yeon-Han Kim;Kyung-Suk Cho;Jaeheung Park;Jaejin Lee;Hoang Ngoc Huy Nguyen;Madeeha Talha
    • Journal of Astronomy and Space Sciences
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    • v.41 no.3
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    • pp.171-194
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    • 2024
  • This study reports comprehensive observations for the G5-level geomagnetic storm that occurred from May 10 to 12, 2024, the most intense event since the 2003 Halloween storm. The storm was triggered by a series of coronal mass ejections (CMEs) originating from the merging of two active regions 13664/13668, which formed a large and complex photospheric magnetic configuration and produced X-class flares in early May 2024. Among the events, the most significant CME, driven by an X2.2 flare on May 9, caught up with and merged with a preceding slower CME associated with an X-class flare on May 8. These combined CMEs reached 1 AU simultaneously, resulting in an extreme geomagnetic storm. Geostationary satellite observations revealed changes in Earth's magnetosphere due to solar wind impacts, increased fluxes of high-energy particles, and periodic magnetic field fluctuations accompanied by particle injections. Extreme geomagnetic storms resulting from the interaction of the solar wind with the Earth's magnetosphere caused significant energy influx into Earth's upper atmosphere over the polar regions, leading to thermospheric heating and changes in the global atmospheric composition and ionosphere. As part of this global disturbance, significant disruptions were also observed in the East Asian sector, including the Korean Peninsula. Ground-based observations show strong negative storm effects in the ionosphere, which are associated with thermospheric heating and resulting in decreases in the oxygen-to-nitrogen ratio (O/N2) in high-latitude regions. Global responses of storm-time prompt penetration electric fields were also observed from magnetometers over the East-Asian longitudinal sector. We also briefly report storm-time responses of aurora and cosmic rays using all-sky cameras and neutron monitors operated by the Korea Astronomy and Space Science Institute (KASI). The extensive observations of the G5-level storm offer crucial insights into Sun-Earth interactions during extreme space weather events and may help establish better preparation for future space weather challenges.

A Study on the Development of Educational Smart App. for Home Economics Classes(1st): Focusing on 'Clothing Preparation Planning and Selection' (가정과수업을 위한 교육용 스마트 앱(App) 개발연구(제1보): 중1 기술·가정 '의복 마련 계획과 선택'단원을 중심으로)

  • Kim, Gyuri;Wee, Eunhah
    • Journal of Korean Home Economics Education Association
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    • v.35 no.3
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    • pp.47-66
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    • 2023
  • The purpose of this study was to develop an educational smart app for classes by reconstructing some of the teaching-learning contents of the clothing preparation planning within the 'clothing preparation planning and selection' curriculum unit. To this end, a teaching-learning process plan was planned for the classes, a smart app was developed for classes, and feedback from home economics teachers and app development experts was received for the developed app. The main composition of the developed app consists of five steps. The first step is to set up a profile using a real photo, ZEPETO or Galaxy emoji, or iPhone Memoji. In the second step, students make a list of clothes by figuring out the types, quantities and conditions of their exisitng wardrobe items. Each piece of clothing is assigned an individual registration number, and stduents can take pictures of the front and back, along with describing key attributes such as type, color, season-appropriateness, purchase date, and current status. Step three guides students in deciding which garments to retain and which to discard. Building on the clothing inventory from the previous step, students classify items to keep and items to dispose of. In Step 4, Deciding How to Arrange Clothing, students decide how to arrange clothing by filling out an alternative scorecard. Through this process, students can learn in advance the subsection of resource management and self-reliance, laying the foundationa for future learning in 'Practice of Rational Consumption Life'. Lastly, in the fifth stage of determining the disposal method, this stage is to develop practical problem-oriented classes on how to dispose of the clothes to be discarded in the thirrd stage by exploring various disposal methods, engaging in group discussions, and sharing opinions. This study is meaningful as a case study as an attempt to develop a smart app for education by an instructor to align teaching plans and educational content with achievement standards for the class. In the future, upgrades will have to be made through user application.

A Study on Hydrogeological Characteristics of Deep-Depth Rock Aquifer by Rock Types in Korea (국내 암종별 고심도 암반대수층 수리지질특성 연구)

  • Hangbok Lee;Chan Park;Dae-Sung Cheon;Junhyung Choi;Eui-Seob Park
    • Tunnel and Underground Space
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    • v.34 no.4
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    • pp.374-392
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    • 2024
  • In order to successfully select a site for deep geological disposal of high-level radioactive waste, it is important to perform the stepwise approach along with the systematic selection and survey of evaluation parameters of geological environmental characteristics suitable for the domestic geological environment. In this study, we evaluated the characteristics of hydraulic conductivity, which is considered the most important evaluation parameter in the field of hydrogeology, targeting a deep-depth rock aquifer where actual disposal facilities are expected to be located. In particular, for the first time in Korea, we obtained in-situ pressure-flow data by directly conducting hydraulic tests in boreholes at depths ranging from 500 m to 750 m in various rock types distributed in Korea (granite/volcanic rock/gneiss/mudstone). And we derived hydraulic conductivity values by rock types and depth using verified analytical methods. For this purpose, precision hydraulic testing equipment developed in-house through this study was used, and detailed investigation procedures based on standard test methods were applied to field tests. As a result of the analysis, the average hydraulic conductivity value was found to be in the range of 10-9 m/s in all granite/volcanic rock/gneiss areas. In the mudstone area, an average hydraulic conductivity value of 10-11 m/s was derived, which was about 100 times (2 orders of magnitude) lower than that of the fractured rock aquifers. Moreover, permeability tended to slightly decrease with depth in fractured rock aquifers (granite and volcanic rock areas) containing many rock fractures. The gneiss area tended to have large local differences in permeability according to the composition of the stratum and the development of fracture zones rather than depth. In mudstone areas with weak fracture development, there was no significant variation in rock permeability according to depth. The hydraulic conductivity results by various rock types and depth presented in this study are expected to be utilized in building a foundational database for the site selection, design, and construction of disposal facilities in Korea.

Ionospheric Responses to the May 2024 G5 Geomagnetic Storm Over Korea, Captured by the Korea Astronomy and Space Science Institute (KASI) Near Real-Time Ionospheric Monitoring System (2024년 5월 G5 지자기 폭풍 때 한반도 상공 전리권 변화: 한국천문연구원 준 실시간 전리권 감시 시스템 관측 결과를 중심으로)

  • Woo Kyoung Lee;Hyosub Kil;Byung-Kyu Choi;Junseok Hong;Se-Heon Jeong;Sujin Kim;Jeong-Heon Kim;Dong-Hyo Sohn;Kyoung-Min Roh;Sung-Moon Yoo;Tae-Yong Yang;Jaeheung Park;Jong-Kyun Chung;Young-Sil Kwak
    • Journal of Space Technology and Applications
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    • v.4 no.3
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    • pp.210-219
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    • 2024
  • This study investigates various ionospheric and thermospheric disturbances around the Korean Peninsula during the G5 geomagnetic storm occurred on May 10, 2024. This level of storm was the first of its magnitude in 21 years, resulting in auroras visible even in South Korea and severe space weather worldwide. The Korea Astronomy and Space Science Institute has been providing ionospheric information over Korea through total electron content (TEC) measurements from the Global Navigation Satellite System (GNSS) and monitoring the impact of ionospheric disturbances on GNSS signals by operating five GNSS scintillation stations in Korea and other countries. During this storm period, large amplitudes of TEC variations were observed over South Korea, along with anomalous TEC enhancements accompanied by strong scintillations at night and persistent TEC depletion on the dayside during the storm's recovery phase. Such daytime TEC depletion disturbances are quite rare, typically occurring only a few times throughout the 11-year solar cycle. While the association of persistent TEC depletion during the daytime with neutral composition disturbances was identified through observations, the causes of TEC enhancement and strong scintillation at night remain unclear. We speculate that the uplift of the ionosphere by storm-induced electric fields is responsible for the TEC enhancement and scintillation, but this hypothesis requires validation based on additional observational data.

Ecological Characteristics of Fraxinus chiisanensis Nakai, an Endemic Plant of Korea (한국 특산식물 물들메나무의 생태적 특성)

  • Jeong-Seok Park;Shin-Young Kwon;Ju-hee Lee;Ji-Eun Byun;So-dam Kim;Seok-Min Yun;Ji-Young Jung
    • Korean Journal of Environment and Ecology
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    • v.38 no.4
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    • pp.375-387
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    • 2024
  • This study investigated the ecological characteristics of Fraxinus chiisanensis Nakai, one of the endemic and rare plant species in Korea, based on its distribution status, characteristics of the growth environment, and species composition. A vegetation survey that analyzed the correlation between species distribution patterns and environmental variables, along with the traits of the emergent plant species, was performed according to the explanation of environmental growth conditions and phytosociological method for the location where F. chiisanensis is found. A total of 19 dominant locations and 9 non-dominant locations of F. chiisanensis were observed in 28 study sites in 12 regions, and a total of 155 taxa were observed. According to the vegetation climate of Korea, the growth environment of the study site where F. chiisanensis is located is characterized as cold and is primarily situated within the northern temperate deciduous broadleaf forest zone. The average elevation was 859m above sea level, with an average rock exposure of 60.4%, soil exposure of 24.7%, and an average slope of 18.7°. The taxa belonging to the top P-NCD(Percentage of Net Contribution Degree) among the emergent species were mostly designated as the taxa emerging in valley vegetation. The correlation analysis of environmental variables revealed that altitude had the strongest correlation, with rock exposure showing the second highest correlation. The ongoing dynamics of the F. chiisanensis forest are anticipated to persist due to the high P-NCD values exhibited by the F. chiisanensis within the shrub and herbaceous layers among the taxa associated with tree species. Most F. chiisanensis habitats are currently situated within protected regions such as national parks, provincial parks, and county parks, where there are relatively minimal human-induced disturbances. However, there is potential for damage in areas not designated as protected, such as forest tending operation sites or new hiking trails. Concerns about declining habitat quality have prompted suggestions for management strategies such as establishing Forest Genetic Resource Reserves in these locations. In addition, follow-up and further research should be conducted to identify possible sites for distribution and establish candidate conservation areas based on various environmental conditions of F. chiisanensis.

A Study on the Garden Architectural Characteristics of Italian Renaissance Villa Medici a Fiesole (이탈리아 르네상스 빌라 메디치 피에졸레의 정원건축적 특성)

  • Choi, Jong-Hee;Choi, Yong-Won;Kim, Kyu-Yeon
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.42 no.1
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    • pp.35-44
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    • 2024
  • The purpose of this study is to investigate the garden architectural characteristics of the Villa Medici a Fiesole, which occupies an important place in the Italian Renaissance garden, and it is concluded as follows. First, the Villa Medici a Fiesole was built between 1451 and 1457 for Giovanni, the son of Cosimo, and then owned by many people and came to the present. It was designed by Michelozzo and is the first newly built Renaissance villa to show Alberti's concept of rural residence. Second, the location is the biggest characteristic of the Villa, which was built on the steep slope of the Fiesole and offers a panoramic view of the landscape of Florence. Third, the overall composition of the garden created using the slope is based on three terraces of different heights, and the overall spatial arrangement is made up of an orthogonal axis at which the vertical and horizontal axes intersect around the villa. Fourth, in the case of vegetation and objects, old paulownia, roses, and potted lemon trees are placed on the first terrace on the three lawn flower beds. Fountain and niche are located at the middle and east end of the terrace. The second terrace cannot be reached through stairs, but only through a villa or a ramp outside the door. The second terrace has a wisteria pergola that leads to a secret garden, and in the center of the pergola, there is a staircase that leads to the third terrace. The Secret Garden takes the form of a quarter garden and consists of an oval pond, a coniferous flowerbed, and magnolias. On the third terrace at the bottom, a symmetrically geometric flowerbed spreads out on both sides of a circular fountain, and large lemon trees are in the center of each flowerbed and four magnolias are planted around the fountain.

A Study Concerning Health Needs in Rural Korea (농촌(農村) 주민(住民)들의 의료필요도(醫療必要度)에 관(關)한 연구(硏究))

  • Lee, Sung-Kwan;Kim, Doo-Hie;Jung, Jong-Hak;Chunge, Keuk-Soo;Park, Sang-Bin;Choy, Chung-Hun;Heng, Sun-Ho;Rah, Jin-Hoon
    • Journal of Preventive Medicine and Public Health
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    • v.7 no.1
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    • pp.29-94
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    • 1974
  • Today most developed countries provide modern medical care for most of the population. The rural area is the more neglected area in the medical and health field. In public health, the philosophy is that medical care for in maintenance of health is a basic right of man; it should not be discriminated against racial, environmental or financial situations. The deficiency of the medical care system, cultural bias, economic development, and ignorance of the residents about health care brought about the shortage of medical personnel and facilities on the rural areas. Moreover, medical students and physicians have been taught less about rural health care than about urban health care. Medical care, therefore, is insufficient in terms of health care personnel/and facilities in rural areas. Under such a situation, there is growing concern about the health problems among the rural population. The findings presented in this report are useful measures of the major health problems and even more important, as a guide to planning for improved medical care systems. It is hoped that findings from this study will be useful to those responsible for improving the delivery of health service for the rural population. Objectives: -to determine the health status of the residents in the rural areas. -to assess the rural population's needs in terms of health and medical care. -to make recommendations concerning improvement in the delivery of health and medical care for the rural population. Procedures: For the sampling design, the ideal would be to sample according to the proportion of the composition age-groups. As the health problems would be different by group, the sample was divided into 10 different age-groups. If the sample were allocated by proportion of composition of each age group, some age groups would be too small to estimate the health problem. The sample size of each age-group population was 100 people/age-groups. Personal interviews were conducted by specially trained medical students. The interviews dealt at length with current health status, medical care problems, utilization of medical services, medical cost paid for medical care and attitudes toward health. In addition, more information was gained from the public health field, including environmental sanitation, maternal and child health, family planning, tuberculosis control, and dental health. The sample Sample size was one fourth of total population: 1,438 The aged 10-14 years showed the largest number of 254 and the aged under one year was the smallest number of 81. Participation in examination Examination sessions usually were held in the morning every Tuesday, Wenesday, and Thursday for 3 hours at each session at the Namchun Health station. In general, the rate of participation in medical examination was low especially in ages between 10-19 years old. The highest rate of participation among are groups was the under one year age-group by 100 percent. The lowest use rate as low as 3% of those in the age-groups 10-19 years who are attending junior and senior high school in Taegu city so the time was not convenient for them to recieve examinations. Among the over 20 years old group, the rate of participation of female was higher than that of males. The results are as follows: A. Publie health problems Population: The number of pre-school age group who required child health was 724, among them infants numbered 96. Number of eligible women aged 15-44 years was 1,279, and women with husband who need maternal health numbered 700. The age-group of 65 years or older was 201 needed more health care and 65 of them had disabilities. (Table 2). Environmental sanitation: Seventy-nine percent of the residents relied upon well water as a primary source of dringking water. Ninety-three percent of the drinking water supply was rated as unfited quality for drinking. More than 90% of latrines were unhygienic, in structure design and sanitation (Table 15). Maternal and child health: Maternal health Average number of pregnancies of eligible women was 4 times. There was almost no pre- and post-natal care. Pregnancy wastage Still births was 33 per 1,000 live births. Spontaneous abortion was 156 per 1,000 live births. Induced abortion was 137 per 1,000 live births. Delivery condition More than 90 percent of deliveries were conducted at home. Attendants at last delivery were laymen by 76% and delivery without attendants was 14%. The rate of non-sterilized scissors as an instrument used to cut the umbilical cord was as high as 54% and of sickles was 14%. The rate of difficult delivery counted for 3%. Maternal death rate estimates about 35 per 10,000 live births. Child health Consultation rate for child health was almost non existant. In general, vaccination rate of children was low; vaccination rates for children aged 0-5 years with BCG and small pox were 34 and 28 percent respectively. The rate of vaccination with DPT and Polio were 23 and 25% respectively but the rate of the complete three injections were as low as 5 and 3% respectively. The number of dead children was 280 per 1,000 living children. Infants death rate was 45 per 1,000 live births (Table 16), Family planning: Approval rate of married women for family planning was as high as 86%. The rate of experiences of contraception in the past was 51%. The current rate of contraception was 37%. Willingness to use contraception in the future was as high as 86% (Table 17). Tuberculosis control: Number of registration patients at the health center currently was 25. The number indicates one eighth of estimate number of tuberculosis in the area. Number of discharged cases in the past accounted for 79 which showed 50% of active cases when discharged time. Rate of complete treatment among reasons of discharge in the past as low as 28%. There needs to be a follow up observation of the discharged cases (Table 18). Dental problems: More than 50% of the total population have at least one or more dental problems. (Table 19) B. Medical care problems Incidence rate: 1. In one month Incidence rate of medical care problems during one month was 19.6 percent. Among these health problems which required rest at home were 11.8 percent. The estimated number of patients in the total population is 1,206. The health problems reported most frequently in interviews during one month are: GI trouble, respiratory disease, neuralgia, skin disease, and communicable disease-in that order, The rate of health problems by age groups was highest in the 1-4 age group and in the 60 years or over age group, the lowest rate was the 10-14 year age group. In general, 0-29 year age group except the 1-4 year age group was low incidence rate. After 30 years old the rate of health problems increases gradually with aging. Eighty-three percent of health problems that occured during one month were solved by primary medical care procedures. Seventeen percent of health problems needed secondary care. Days rested at home because of illness during one month were 0.7 days per interviewee and 8days per patient and it accounts for 2,161 days for the total productive population in the area. (Table 20) 2. In a year The incidence rate of medical care problems during a year was 74.8%, among them health problems which required rest at home was 37 percent. Estimated number of patients in the total population during a year was 4,600. The health problems that occured most frequently among the interviewees during a year were: Cold (30%), GI trouble (18), respiratory disease (11), anemia (10), diarrhea (10), neuralgia (10), parasite disease (9), ENT (7), skin (7), headache (7), trauma (4), communicable disease (3), and circulatory disease (3) -in that order. The rate of health problems by age groups was highest in the infants group, thereafter the rate decreased gradually until the age 15-19 year age group which showed the lowest, and then the rate increased gradually with aging. Eighty-seven percent of health problems during a year were solved by primary medical care. Thirteen percent of them needed secondary medical care procedures. Days rested at home because of illness during a year were 16 days per interviewee and 44 days per patient and it accounted for 57,335 days lost among productive age group in the area (Table 21). Among those given medical examination, the conditions observed most frequently were respiratory disease, GI trouble, parasite disease, neuralgia, skin disease, trauma, tuberculosis, anemia, chronic obstructive lung disease, eye disorders-in that order (Table 22). The main health problems required secondary medical care are as fellows: (previous page). Utilization of medical care (treatment) The rate of treatment by various medical facilities for all health problems during one month was 73 percent. The rate of receiving of medical care of those who have health problems which required rest at home was 52% while the rate of those who have health problems which did not required rest was 61 percent (Table 23). The rate of receiving of medical care for all health problems during a year was 67 percent. The rate of receiving of medical care of those who have health problems which required rest at home was 82 percent while the rate of those who have health problems which did not required rest was as low as 53 percent (Table 24). Types of medical facilitied used were as follows: Hospital and clinics: 32-35% Herb clinics: 9-10% Drugstore: 53-58% Hospitalization Rate of hospitalization was 1.7% and the estimate number of hospitalizations among the total population during a year will be 107 persons (Table 25). Medical cost: Average medical cost per person during one month and a year were 171 and 2,800 won respectively. Average medical cost per patient during one month and a year were 1,109 and 3,740 won respectively. Average cost per household during a year was 15,800 won (Table 26, 27). Solution measures for health and medical care problems in rural area: A. Health problems which could be solved by paramedical workers such as nurses, midwives and aid nurses etc. are as follows: 1. Improvement of environmental sanitation 2. MCH except medical care problems 3. Family planning except surgical intervention 4. Tuberculosis control except diagnosis and prescription 5. Dental care except operational intervention 6. Health education for residents for improvement of utilization of medical facilities and early diagnosis etc. B. Medical care problems 1. Eighty-five percent of health problems could be solved by primary care procedures by general practitioners. 2. Fifteen percent of health problems need secondary medical procedures by a specialist. C. Medical cost Concidering the economic situation in rural area the amount of 2,062 won per residents during a year will be burdensome, so financial assistance is needed gorvernment to solve health and medical care problems for rural people.

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Occurrence and Chemical Composition of White Mica from Zhenzigou Pb-Zn Deposit, China (중국 Zhenzigou 연-아연 광상의 백색운모 산상과 화학조성)

  • Yoo, Bong Chul
    • Korean Journal of Mineralogy and Petrology
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    • v.35 no.2
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    • pp.83-100
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    • 2022
  • The Zhenzigou Pb-Zn deposit, which is one of the largest Pb-Zn deposit in the northeast of China, is located at the Qingchengzi mineral field in Jiao Liao Ji belt. The geology of this deposit consists of Archean granulite, Paleoproterozoinc migmatitic granite, Paleo-Mesoproterozoic sodic granite, Paleoproterozoic Liaohe group, Mesozoic diorite and Mesozoic monzoritic granite. The Zhenzigou deposit which is a strata bound SEDEX or SEDEX type deposit occurs as layer ore and vein ore in Langzishan formation and Dashiqiao formation of the Paleoproterozoic Liaohe group. White mica from this deposit are occured only in layer ore and are classified four type (Type I : weak alteration (clastic dolomitic marble), Type II : strong alteration (dolomitic clastic rock), Type III : layer ore (dolomitic clastic rock), Type IV : layer ore (clastic dolomitic marble)). Type I white mica in weak alteration zone is associated with dolomite that is formed by dolomitization of hydrothermal metasomatism. Type II white mica in strong alteration zone is associated with dolomite, ankerite, quartz and alteration of K-feldspar by hydrothermal metasomatism. Type III white mica in layer ore is associated with dolomite, ankerite, calcite, quartz and alteration of K-feldspar by hydrothermal metasomatism. And type IV white mica in layer ore is associated with dolomite, quartz and alteration of K-feldspar by hydrothermal metasomatism. The structural formulars of white micas are determined to be (K0.92-0.80Na0.01-0.00Ca0.02-0.01Ba0.00Sr0.01-0.00)0.95-0.83(Al1.72-1.57Mg0.33-0.20Fe0.01-0.00Mn0.00Ti0.02-0.00Cr0.01-0.00V0.00Sb0.02-0.00Ni0.00Co0.02-0.00)1.99-1.90(Si3.40-3.29Al0.71-0.60)4.00O10(OH2.00-1.83F0.17-0.00)2.00, (K1.03-0.84Na0.03-0.00Ca0.08-0.00Ba0.00Sr0.01-0.00)1.08-0.85(Al1.85-1.65Mg0.20-0.06Fe0.10-0.03Mn0.00Ti0.05-0.00Cr0.03-0.00V0.01-0.00Sb0.02-0.00Ni0.00Co0.03-0.00)1.99-1.93(Si3.28-2.99Al1.01-0.72)4.00O10(OH1.96-1.90F0.10-0.04)2.00, (K1.06-0.90Na0.01-0.00Ca0.01-0.00Ba0.00Sr0.02-0.01)1.10-0.93(Al1.93-1.64Mg0.19-0.00Fe0.12-0.01Mn0.00Ti0.01-0.00Cr0.01-0.00V0.00Sb0.00Ni0.00Co0.05-0.01)2.01-1.94(Si3.32-2.96Al1.04-0.68)4.00O10(OH2.00-1.91F0.09-0.00)2.00 and (K0.91-0.83Na0.02-0.01Ca0.02-0.00Ba0.01-0.00Sr0.00)0.93-0.83(Al1.84-1.67Mg0.15-0.08Fe0.07-0.02Mn0.00Ti0.04-0.00Cr0.06-0.00V0.02-0.00Sb0.02-0.01Ni0.00Co0.00)2.00-1.92(Si3.27-3.16Al0.84-0.73)4.00O10(OH1.97-1.88F0.12-0.03)2.00, respectively. It indicated that white mica of from the Zhenzigou deposit has less K, Na and Ca, and more Si than theoretical dioctahedral mica. Compositional variations in white mica from the Zhenzigou deposit are caused by phengitic or Tschermark substitution [(Al3+)VI+(Al3+)IV <-> (Fe2+ or Mg2+)VI+(Si4+)IV] substitution. It means that the Fe in white mica exists as Fe2+ and Fe3+, but mainly as Fe2+. Therefore, white mica from layer ore of the Zhenzigou deposit was formed in the process of remelting and re-precipitation of pre-existed minerals by hydrothermal metasomatism origined metamorphism (greenschist facies) associated with Paleoproterozoic intrusion. And compositional variations in white mica from the Zhenzigou deposit are caused by phengitic or Tschermark substitution [(Al3+)VI+(Al3+)IV <-> (Fe2+ or Mg2+)VI+(Si4+)IV] substitution during hydrothermal metasomatism depending on wallrock type, alteration degree and ore/gangue mineral occurrence frequency.

Hydrochemistry and Noble Gas Origin of Various Hot Spring Waters from the Eastern area in South Korea (동해안지역 온천유형별 수리화학적 특성 및 영족기체 기원)

  • Jeong, Chan-Ho;Nagao, Keisuke;Kim, Kyu-Han;Choi, Hun-Kong;Sumino, Hirochika;Park, Ji-Sun;Park, Chung-Hwa;Lee, Jong-Ig;Hur, Soon-Do
    • Journal of Soil and Groundwater Environment
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    • v.13 no.1
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    • pp.1-12
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    • 2008
  • The purpose of this study is to characterize the hydrogeochemical characteristics of hot spring waters and to interpret the source of noble gases and the geochemical environment of the hot spring waters distributed along the eastern area of the Korean peninsula. For this purpose, We carried out the chemical, stable isotopic and noble gas isotopic analyses for eleven hot spring water and fourteen hot spring gas samples collected from six hot spring sites. The hot spring waters except the Osaek hot spring water show the pH range of 7.0 to 9.1. However, the Osaek $CO_2$-rich hot spring water shows a weak acid of pH 5.7. The temperature of hot spring waters in the study area ranges from $25.7^{\circ}C$ to $68.3^{\circ}C$. Electrical conductivity of hot spring waters varies widely from 202 to $7,130{\mu}S/cm$. High electrical conductivity (av., $3,890{\mu}S/sm$) by high Na and Cl contents of the Haeundae and the Dongrae hot spring waters indicates that the hot spring waters were mixed with seawater in the subsurface thermal system. The type of hot springs in the viewpoint of dissolved components can be grouped into three types: (1) alkaline Na-$HCO_3$ type including sulfur gas of the Osaek, Baekam, Dukgu and Chuksan hot springs, and (2) saline Na-Cl type of the Haeundae and Dongrae hot springs, and (3) weak acid $CO_2$-rich Na-$HCO_3$ type of Osaek hot spring. Tritium ratios of the Haeundae and the Dongrae hot springs indicate different residence time in their aquifers of older water of $0.0{\sim}0.3$ TU and younger water of $5.9{\sim}8.8$ TU. The ${\delta}^{18}O$ and ${\delta}D$ values of hot spring waters indicate that they originate from the meteoric water, and that the values also reflect a latitude effect according to their locations. $^3He/^4He$ ratios of the hot spring waters except Osaek $CO_2$-rich hot spring water range from $0.1{\times}10^{-6}$ to $1.1{\times}10^{-6}$ which are plotted above the mixing line between air and crustal components. It means that the He gas in hot spring waters was originated mainly from atmosphere and crust sources, and partly from mantle sources. The Osaek $CO_2$-rich hot spring water shows $3.3{\times}10^{-6}$ in $^3He/^4He$ ratio that is 2.4 times higher than those of atmosphere. It provides clearly a helium source from the deep mantle. $^{40}Ar/^{36}Ar$ ratios of hot spring water are in the range of an atmosphere source.

Influence of Nutritional Supplementation to the Substrate on Vegetative and Reproductive Growth of Winter Mushroom, Flammulina velutipes (Curt. ex Fr.) Sing. and Chemical Changes of the substrates Produced during Growth of the Fungus (톱밥 배지(培地)에 대(對)한 영양첨가(營養添加)가 팽이버섯의 생장(生長)및 배지(培地)의 화학적(化學的) 성분(成分) 변화(變化)에 미치는 영향(影響))

  • Chang, Hak-Gil
    • The Korean Journal of Mycology
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    • v.4 no.1
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    • pp.31-44
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    • 1976
  • The studies were carried out to examine the effects of supplementation of nutritional substances and physical conditions in substrate on the mycelial growth and yield of fresh sporophores of winter mushroom, Flammulina velutipes(Curt. ex Fr.) Sing. and to obtain further informations on the nutritional requirements of the fungus with reference to improvement of substrate through [analysis of chemical composition of the substrates during the cultivation period. The results obtained are summarized as follows: 1. The best yield of fresh sporophores, 84.4 g per 280 g substrate in a bottle, was obtained from the mixture of poplar sawdust 10 and rice bran 3 by volume when Flammulina velutipes was cultivated on the poplar sawdust supplemented by rice bran, wheat bran, cattle manure and various combinations of these materials as nutrient sources. The substrates of poplar sawdust 10 plus rice bran 3 and 2 or wheat bran 3 with a higher yield of fresh sporophores showed a comparatively higher content of total nitrogen. total sugar, and potassium. 2. The mycelial growth of the fungus was compared on the substrates of poplar sawdust supplemented by the several nutrient sources and poplar sawdust alone. The fastest linear growth occurred on substrates of poplar sawdust alone and poplar sawdust plus cattle manure deficient in sugar and nitrogen sources, but mycelial density was more sparse on the substrates. Also, growth in a solution extracted from these substrates was very meager. 3. In the substrates which varied with bulk density and moisture content optimum bulk density and moisture content for mycelial growth was 0.2g/cc and 72% on a dry weight basis, respectively, but the highest yield of fresh sporophores was obtained at the bulk density of 0.3g/cc and moisture content of 67%. 4. By increasing the ratio of rice bran in poplar sawdust the loss of total weight and ash, content at each stage was increased, and during the cultivation period of 75 days, loss of total weight of the substrates at inoculation was 17.8 to 28.8% and ash content increased about 12%. 5. 11 to 14% of the cellulose and 3 to 4% of the lignin content per original substrate were decreased without a great difference depending of the mixing ratio of rice bran. The soluble glucose concentration in the substrates was increased during the same period. 6. In the process of vegetative and reproductive growth of the fungus upon the substrates, the total nitrogen was increased in quantity per dry weight of sample but was reduced in absolute quantity to a minute extent. There is no great changes in content of organic nitrogen including amino acid nitrogen, and hydrolysable ammonium nitrogen during the vegetative growth period, but occurrence of sporophores resulted in a decrease in the nitrogen content of these forms. On the one hand, by an increase of additive amounts of rice bran, nitrogen contents of these forms were higher and the reduction range during the reproductive growth period became wider. 7. Mycelial growth of the fungus was accelerated in various liquid media supplemented with organic nitrogen sources such as peptone and yeast extract in comparison with addition of inorganic nitrogen sources. Furthermore, mycelial growth was mere vigorous in the media with higher content of organic nitrogen sources.

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