• Title/Summary/Keyword: Predominant period

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Bacterial Community Structure of Food Wastewater Treatment System Combined with Rotating Biological Contactor and Tapered Aeration Reactor (회전접촉장치와 점감포기 반응조를 이용한 식품폐수 처리시설의 세균군집 구조)

  • Jeong, Soon-Jae;Nam, Ji-Hyun;Bae, Woo-Keun;Lee, Dong-Hun
    • Korean Journal of Microbiology
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    • v.46 no.2
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    • pp.169-176
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    • 2010
  • A pilot-scale wastewater treatment plant combined with rotating biological contactor and tapered aeration reactors was operated with the wastewater discharged from a food factory for 5 months. The bacterial communities of this plant were investigated by terminal restriction fragment length polymorphism (T-RFLP) and phylogenetic analysis of 16S rRNA genes. In spite of high concentration of nitrogen and phosphorus as well as organic carbon, removal efficiency of chemical oxygen demand, total nitrogen, and total phosphorus was 98%, 93%, and 95%, respectively. Bacterial community at the initial operation stage was clearly distinguished from that of the stable operation stage. The most predominant phylum in the sample of stable stage was Bacteroidetes. Major population of operation period was Haliscomenobacter, Sphaerotilus, and candidate division TM7, which were classified as filamentous bacteria. However, sludge bulking caused by these bacteria was not observed. The population that has a close relationship with Haliscomenobacter increased during the stable operation stage, emerging as the most predominant group. These results suggest that the filamentous bacteria participated in nutrient removal when using rotating biological contactor and tapered aeration reactor.

Electroencephalographic brain frequency in athletes differs during visualization of a state of rest versus a state of exercise performance: a pilot study

  • Berk, Lee;Mali, Deeti;Bains, Gurinder;Madane, Bhagwant;Bradburn, Jessica;Acharya, Ruchi;Kumar, Ranjani;Juneja, Savleen;Desai, Nikita;Lee, Jinhyun;Lohman, Everett
    • Physical Therapy Rehabilitation Science
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    • v.4 no.1
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    • pp.28-31
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    • 2015
  • Objective: Psychomotor imagery has been widely used to improve motor performance and motor learning. Recent research suggests that during visualization, changes occur in neurophysiological networks that make physical practice more effective in configuring functional networks for skillful behaviors. The aim of our pilot study was to determine if there was change and to what extent there was differentiation in modulation in electroencephalography (EEG) frequencies between visualizing a state of rest and a state of exercise performance and to identify the preponderant frequency. Design: Quasi-experimental design uncontrolled before and after study. Methods: EEG brain wave activity was recorded from 0-40 Hz from nine cerebral cortical scalp regions F3, Fz, F4, C3, Cz, C4, P3, POz, and P4 with a wireless telemetric EEG system. The subjects, while sitting on a chair with eyes closed, were asked to visualize themselves in a state of routine rest/relaxation and after a period of time in a state of their routine exercise performance. Results: The gamma frequency, 31-40 Hz, (${\gamma}$) was the predominant wave band in differentiation between visualizing a state of rest versus visualizing a state of exercise performance. Conclusions: We suggest these preliminarily findings show the EEG electrocortical activity for athletes is differentially modulated during visualization of exercise performance in comparison to rest with a predominant ${\gamma}$ wave band frequency observed during the state of exercise. Further controlled experimental studies will be performed to elaborate these observations and delineate the significance to optimization of psychomotor exercise performance.

A Study on the Removal of Ammonia by Using Peat Biofilter (미생물 활성토탄을 이용한 암모니아 제거에 관한 연구)

  • Choung, Youn Kyoo;Ahn, Jun Seong
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.14 no.3
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    • pp.655-668
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    • 1994
  • Conventional deodorization filters using soil and compost reach the capacity limitation of deodorization in short period, because its removal mechanism primarily depends on adsorption. Therefore, in this study the experiment was performed on the removal of ammonia which is a strong inorganic malodor, frequently emitted from night soil treatment plants and sewage treatment plants, by seeding activated sludges on the bio-peat containing higher organic contents, water conservation capacity, permeability and lower pressure drop. As a result, in raw peat filter natural ammonia outlet was observed in consequence of pH increase resulted from ammonia ionizing in liquid phase. Ammonia removal mechanism primarily depended on the adsorption onto the anion colloidal substances in peat. In peat bio-filter, theoretical ammonium salts ratio was higher than that of raw peat, resulted from slight pH increase by microorganism activity, however, the experimetal value of ammonia-nitrogen accumulated in bio-peat was lower than that of raw peat because of nitrification by nitrifying bacteria. In the initial reaction period, adsorption was predominant in the ammonia removal mechanism, but nitrification was conspicuous after the middle period. Mass balance of nitrogen was established using experimental data of input $NH_3$ loading, output $NH_3$ loading, $NH_4{^+}$-N, $NO_x$-N, and Org-N. The critical time of unsteady state, which is the maximum activating point of microorganism in bio-filter, was determined using experimental data, and the ammonia adsorption curve was computed using regression analysis. On the basis of the results obtained by above analysis, the delay days for the saturation of adsoption capacity in peat bio-filter was calculated.

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Changes of Aflatoxins During the Ripening of Korean Soy Paste and Soy Sauce and the Characteristics of the Changes-Part 1. Effect of Bacillus subtilis on the Growth and Aflatoxin Production of Aspergillu parasiticus (한국산 전통 간장과 된장의 숙성중 aflatoxin의 변화와 그 특징-제1보. 경쟁 미생물(Bacillus subtilis)이 Aspergillu parasiticus의 성장과 aflatoxin 생성에 미치는 영향)

  • 김종규;노우섭
    • Journal of Food Hygiene and Safety
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    • v.13 no.3
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    • pp.313-317
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    • 1998
  • This study was perfonned to investigate the possible effect of Bacillus subtilis which is the predominant species of bacteria in Korean soy sauce, soy paste, and Meju (soybean cake) on the growth and aflatoxin production of Aspergillus parasiticus ATCC 15517. The microorganisms were grown in a modified APT broth and incubated at $30^{\circ}C$ for 12 days. Aflatoxins were determined using high performance liquid chromatography (HPLC). A remarkable inhibition of the growth of Aspergillus parasiticus was observed during the incubation period when in the presence of B. subtilis (mixed culture). Dry mycelial weight in the mixed culture was significantly reduced by 85.3% in comparison to the control at the end of the incubation period (p<0.01). Lower levels of aflatoxins were found in the mixed culture than in the monoculture. At the end of the incubation period aflatoxin production was significantly inhibited by more than 50% (p<0.05). These results indicate that B. subtilis mainly inhibites the growth and aflatoxin production of toxigenic Aspergillus in Meju, soy sauce and soy paste. Although its effect on aflatoxin production was less pronounced, we could expect more inhibition by another bacteria related with fermentation in Meju.

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The Analysis of Literature : Prevention of Depression through Exercise Program for the Elderly (우울증 예방을 위한 노인 운동프로그램 문헌 고찰)

  • Kim, Dae-Hoon;Seo, Dong-Nyeuck
    • Journal of the Korean Applied Science and Technology
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    • v.37 no.4
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    • pp.848-859
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    • 2020
  • This study selected 42 domestic preceded literatures that applied exercise programs to the elderly for the past 10 years from 2010 to the first half of 2020 to analyze the characteristics of preceded research, applied period of exercise programs, configuration of exercise programs, and effectiveness of exercise programs on elderly depression, and the conclusion is as follows. First, the majority of the subjects were female and male/female elderly people in the preceding literature, and it appeared that there were no male subjects alone for any of the studies showed. The majority of the ages were over 65 years old, and the number of subjects was 50 or less. In the group, preceded research with exercise/control groups was mostly predominant, and the participated institutions and regions accounted for the majority of the residential area/public institutions and sanatorium. Second, the period of the exercise program was mostly applied for more than 12 weeks, and the frequency of exercise per week was 1-2 times and 3-4 times. Most of the preceding literature was applied with a 60-minute exercise program during the one-time exercise period. Third, most of the contents of the exercise program consisted of a aerobic exercise alone and combination of aerobic·anaerobic exercise. Fourth, it was confirmed that the effects of exercise programs were effective in physical fitness factors as well as in depression and cognitive function.

The Vegetational History of korea During the Holocene Period (홀로세 중 한국의 식생사)

  • 강우석
    • The Korean Journal of Quaternary Research
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    • v.8 no.1
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    • pp.9-22
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    • 1994
  • The vegetational and environmental history of Korea during the Holocene period has reconstructed by the use of folral, palaeoclimatogical, archaeological data and written records. From 10,000 to 6,700 yeat B.P. in mid-eastern Korea, deciduous broadieaved trees gradually increased trees, notably at c.8,000 years B.P. From 6,700 to 4,500 years B.P., the vegetation remained dominated by Quercus and pinus(Diploxylon). Vegetational informations suggest the postglacial hypsithermal from c.8,000 to 4,500 years b.p. After 4,500 until 1,400 years B.P., the admixture of cryophilous trees in midland and thermophilous trees in south seems to imply the latitudinal divisions of vegetation and climate. The presence of cultivated rice pollen as well as non-arboreal pollen and spores indicates an increased rate of deforestation. From 1,400 years B.P., there was a sharp decrease in the representation of temperate trees, but the presence of the cryophilous genera Abies and pinus (Haploxylon) is noticea-ble and might be related to the occurrence of Little Ice Age. Fossil pollen diagram from western Korea and eastern Korea since 6,250 and 10,000 yeats B.P., respectively have enabled to compare vegetational dis-tribution patterns and changes in the Holocene period. In western Korea, Alnus- dominated vegetation continued from 6,250 to 1,500 years B.P., but pinus took over Alnus from 1,500 years B.P. In eastern Korea, however, Quercus and pinus dominated from 10,000 to 2,000 years B.P., but pinus be-came predominant from 2,000 years B.P. On a time- spatial basis, different vegetational distribution pattern can be recognised between western and east-ern Korea. The use of seven historical records which is unique to Korea also enabled to reconstruct the distributional pattern and temporal change of vegetation from 1425 to 1928.

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Species Composition and Spatial Distribution of Euphausiids of the Yellow Sea and Relationships with Environmental Factors

  • Yoon, Won-Duk;Yang, Joon-Yong;Lim, Dong-Hyun;Cho, Sung-Hwan;Park, Gyung-Soo
    • Ocean Science Journal
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    • v.41 no.1
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    • pp.11-29
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    • 2006
  • We investigated species composition and spatial distribution of the euphausiid community in the Yellow Sea and identified the relationship with environmental factors (temperature, salinity, chlorophyll $\alpha$, nitrate, phosphate, and silicate) using bimonthly data from June, 1997 to April, 1998. The environment varied during the sampling period. In warm seasons, thermocline was well developed rendering lower temperature and higher salinity and nutrient concentrations in the bottom layer. During cold seasons the water column was well mixed and no such vertical stratification was noted. Horizontal distribution of temperature, however, differed slightly between near-coast and offshore areas because of the shallow depth of the Yellow Sea, and between southern and northern areas because of the intrusion of water masses such as Yellow Sea Warm Current and Changjiang River Diluted Water. Four euphausiid species were identified: Euphausia pacifica, E. sanzoi, Pseudeuphausia sp. and Stylocheron affine. E. sanzoi and S. affine were collected, just one juvenile each, from the southern area in June and December, respectively. Pseudeuphausia sp. were collected in the eastern area all the year round except June. E. pacifica occurred at the whole study area and were the predominant species, representing at least 97.6% of the euphausiid abundance. Further, the distribution pattern of the species was varied in regards to developmental stages (adult, furcilia, calyptopis, egg). From spring to fall, E. pacifica adults were abundant in the central area where the Yellow Sea Bottom Cold Water prevailed. Furcilia and calyptopis extended their distribution into nearly all the study area during the same period. From late fall to winter, adults were found at the near-coastal are a with similar pattern for furcilia and calyptopis. The distribution pattern of E. pacifica was consistent regarding temperature, salinity, and three nutrients during the sampling period, whereas chlorophyll $\alpha$ showed a different pattern according to the developmental stages. The nutrients should indirectly affect via chlorophyll $\alpha$ and phytoplankton concentration. With respect to these results, we presented a scenario about how the environmental factors along with the water current affect the distribution of E. pacifica in the Yellow Sea.

Variation Pattern Analysis on the Air and Surface Water Temperatures of the Yellow Sea Monitoring Buoy (황해중부부이에서 관측된 기온 및 표층수온의 변화양상 분석)

  • Cho, Hong-Yeon;Jeong, Jin-Yong;Shim, Jae-Seol;Kim, Seon-Jeong
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.22 no.5
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    • pp.316-325
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    • 2010
  • Harmonic analyses are carried out in order to obtain the major frequency components of the air temperature (AT) and surface water temperature (SWT) data monitored in the Middle Area of the Yellow Sea (Yellow Sea monitoring buoy). The analysis shows the annual and semi-annual components are predominant and the higher frequency components are relatively weak with contribution to the short fluctuations, i.e. below $0.2{\sim}0.5^{\circ}C$, in the AT and SWT. The standard deviation of the AT residual is 2.4 times larger than that of the SWT residual and the occurrence frequency distributions of the AT and SWT residual components are both closely fitted to a normal-distribution function. The variation pattern on the AT-SWT plane forms the clear continuous hysteresis loop in anti-clockwise direction which is composed of the AT-SWT rising period, AT-SWT falling period, and the constant SWT period in winter season.

A Study I on the fashion trends of wedding dresses in the 20th century (20세기 웨딩드레스의 유행변화에 관한 연구 I)

  • Shin, Kyeong-Seub
    • Journal of Fashion Business
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    • v.15 no.5
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    • pp.69-86
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    • 2011
  • The objective of this research is to unveil the dynamic changes of the trends in wedding dresses during the 20th Century. The studies were carried out in two forms; firstly by observing the actual wedding dresses worn by people at that time, and secondly by conducting formative comparisons between those dresses with the ones appeared in movies corresponding to that period. Movies provide an invaluable insight into the era's wedding dresses fashion trends since they function as intimate bridges in connection with the time's audience, and the visible imageries accurately reflect the characteristics embedded within that time frame. As there are no precedent studies regarding this topic, this thesis can serve as vital research data for the wedding dress industry. Research data regarding the actual wedding dresses were collected from books and museum web sites. The object of movies were films produced before World War II that contained both the background settings of the 20th Century and wedding dresses, of which photographic imageries were captured. Research analysis was then conducted by merging these data with findings from relevant books and internet materials. The results of the thesis are as the following: The 1900s was an extension of the 19th Century's popular fashion trend which can be characterized as the S curve silhouettes of the Edwardian period when long trains and long veils symbolized wealth and social power. In the 1910s, high waist silhouettes with soft wrinkles were prevalent as attire suitable for active mobility with practical functionality were highly regarded. During the 1920s, the flapper style became the dominant trend. Hem lines of the skirts were curled in the form of the scallop and laces were the most widely used raw materials. By the 1930s, wedding dresses that reinterpreted the glamorous sheath lines, practical two piece styles, and retro-styles became predominant. The 1940s saw the advent of ready-made wedding dresses made of synthesized materials; practical military style suits and casuals sometimes substituted the wedding dresses. And although the wedding dresses in the movies were primarily costumes to express the personalities of the characters, they were also reinterpreted as manifestations of the formative characteristics of each relative period that pursued very distinct and diverse features.

Prevalence of Nosema and Virus in Honey Bee (Apis mellifera L.) Colonies on Flowering Period of Acacia in Korea

  • Hong, In-Pyo;Woo, Soon-Ok;Choi, Yong-Soo;Han, Sang-Mi;Kim, Nam-Suk;Kim, Hye-Kyung;Han, Sang-Hoon;Lee, Man-Young;Lee, Myeong-Lyeol;Byeon, Kyu-Ho
    • Mycobiology
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    • v.39 no.4
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    • pp.317-320
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    • 2011
  • Honey production from approximately 1.6 million colonies owned by about 199,000 Korean beekeepers was almost 23,000 metric tons in 2009. Nosema causes significant losses in honey production and the virus decreases population size. We initiated a survey of honey bee colonies on the blooming period of Acacia to determine the prevalence of Nosema and virus in 2011. Most Korean beekeepers have moved from the south to north of Korea to get Acacia nectar for 2 mon. This provided a valuable opportunity to sample bees originating from diverse areas in one location. Twenty hives owned by 18 beekeepers were sampled in this year. Nosema spore counts ranged from zero to 1,710,000 spores per bee. The average number of nosema spores per bee was 580,000. Approximately 95% of the colonies were infected with Nosema, based on the presence of spores in the flowering period of Acacia. This indicates that Nosema is the predominant species affecting honeybee colonies. Also, the seven most important honeybee viruses were investigated by reverse transcription-PCR. Among them, four different viruses were detected in samples. Black queen cell virus was present in all samples. Chronic bee paralysis virus was detected in 10% of samples. Deformed wing virus was present in only 5% of the samples. Prevalence of Sacbrood virus was 15%. However, Cloudy wing virus, Israel acute paralysis virus and kashmir bee virus were not detected in any of samples.