• International Journal of Clinical Preventive Dentistry
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• v.14 no.4
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• pp.228-234
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• 2018

Objective: The authors have experimented for the artificial plaque removal effect of several kinds of 360 degree rotating head typed tooth-brushes with sonic vibratory actioned by using of automatic machine for horizontal scrub method in order to find the better toothbrush type for plaque removal. Methods: The experiment was conducted on three medium to 360 degree rotating head toothbrushes, a medium sized toothbrush and a medium sized toothbrush, and a flat toothbrush consisting of 30 ordinary toothbrushes. A brushing machine with horizontal scrubbing was manufactured and had variations of the end of the bristle attached to or near the surface of the teeth, a vibrating wave action force of 16,000 or 18,000 cycles per minute, and a working time of 2 or 3 minutes. The tooth removal effect was confirmed by scanning and analyzing images with a computer program after automatic brushing with the machine. The elimination rate results for each group were analyzed using the independent t-test and one-way ANOVA test. Results: It revealed the most in removal effect for the artificial plaque in such conditions as action at near the tooth surface with 18,000 cycle for 3 minutes in case of using A, B, and C tooth-brush. And it has more removal effect rate than for using the plane tooth-brush (p<0.05). Conclusion: It was recommended to develop the 360 degree rotating head and vibratory toothbrush focusing to use near the tooth surface with 18,000 cycles of vibration for 3 minutes at one site of the teeth area.

• CELLMED
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• v.5 no.1
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• pp.7.1-7.7
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• 2015

According to Ayurveda, an individual can be classified into any one of the seven constitutional types (Prakriti) depending on the dominance of one, two, or three Doshas. A 'Dosha' is representative of fundamental mechanisms that are responsible for homeostasis, and thus, to health. In the recent years, there have been several efforts to see whether certain physiological, haematological or biochemical parameters have any relationship with the constitutional types or not. The objective of the present study was to see if the results of autonomic function tests vary according to Prakriti of an individual. We conducted this study in clinically healthy volunteers of both the gender belonging to the age group of 17 to 35 years after obtaining their written consent. The Prakriti of these volunteers was assessed on the basis of a validated questionnaire and also by traditional method of interviewing. After confirming that the primary Dosha ascertained by both these methods matched, 106 volunteers were grouped into three on the basis of primary Dosha and were subjected to various autonomic function tests such as cold pressor test, standing-to-lying ratio, Valsalva ratio and pupillary responses such as pupil cycle time and pupil size measurement in light and dark. The results suggest that, the autonomic function tests in the healthy individuals may correlate linearly with the primary Dosha expressed in an individual. In particular, people with Kapha as the most dominant Dosha showed a tendency to have either a higher parasympathetic activity or a lower sympathetic activity with respect to their cardiovascular reactivity in comparison to the individuals with Pitta or Vata as the most dominant Dosha.

• Tunnel and Underground Space
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• v.22 no.1
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• pp.32-42
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• 2012

It is very difficult to capture the weathering characteristics of rock because of limitation caused by time and space. A new scheme of experiment that includes physical and chemical weathering processes was implemented on Cretaceous granitic rock samples from Kimhae area to investigate the variations of geomechanical properties of deteriorated rocks due to artificial weathering processes. The seismic velocity was found to decrease with increasing artificial weathering cycle. Effective porosity and absorption tend to increase with artificial weathering processes. The amount of deterioration of rock samples depend on pre-test degree of weathering. Effective porosity, absorption and seismic velocity can be used as the measure of weathering characteristics of granite in the study area. Weathering is accelerated by combined effect of physical and chemical weathering processes. The new experimental methodology conducted in this study has strong capability to analyze the weathering characteristics of rocks.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.8 no.4
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• pp.349-356
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• 2003

A continuous monitoring of sedimentation rate and textural characteristics of surface sediments was carried out on the tidal flats in Kwangyang Bay, middle South Sea for two years on an every-two-monthly basis. This study shows that during the winter the tidal flats receive a thin surface layer of which texture becomes finer. In summer, the surface sediments were subject to rather abrupt erosion by occational typhoons and heavy rainfall resulting in a coarse-silt dominated texture. Due to nearly closed geomorphology of Kwangyang Bay, local waves created in the bay during winter are much subdued, in contrast to the rough wave climate and associated sedimentary cycle for open-type tidal flats in the Yellow Sea. In addition, unexpected artificial effects on the tidal-flat sedimentation by construction of a huge industrial complex along the shoreline of the bay are observed from a nearby tidal flat. Here, the sediments were consistently eroded without any sign of natural seasonal variations.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.18 no.4
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• pp.266-276
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• 2013

The ocean is the largest reservoir of carbon in the climate system. Atmospheric $CO_2$ is efficiently transferred to the deep ocean by a process called the biological carbon pump: photosynthetic fixation of $CO_2$ at the sea surface and remineralization of sinking organic carbon at depths are main causes for the vertical contrast of carbon in the ocean. The sequestered carbon to the deep ocean returns to the sea surface by ocean circulation. Part of the upwelled $CO_2$ leaks into the atmosphere through air-sea gas exchange. It has been suggested that the air-sea partitioning of carbon has varied in concert with the glacial-interglacial climate variations, due partly to changes in ocean circulation. In this review paper, we briefly summarize key concepts of the oceanic carbon pump. We also discuss the response of the air-sea carbon partitioning to change in ocean circulation in the context of the glacial-interglacial climate change.

• Journal of Veterinary Science
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• v.22 no.1
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• pp.2.1-2.10
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• 2021

Background: Diseases related to cerebrospinal fluid flow, such as hydrocephalus, syringomyelia, and Chiari malformation, are often found in small dogs. Although studies in human medicine have revealed a correlation with cerebrospinal fluid flow in these diseases by magnetic resonance imaging, there is little information and no standard data for normal dogs. Objectives: The purpose of this study was to obtain cerebrospinal fluid flow velocity data from the cerebral aqueduct and subarachnoid space at the foramen magnum in healthy beagle dogs. Methods: Six healthy beagle dogs were used in this experimental study. The dogs underwent phase-contrast and time-spatial labeling inversion pulse magnetic resonance imaging. Flow rate variations in the cerebrospinal fluid were observed using sagittal time-spatial labeling inversion pulse images. The pattern and velocity of cerebrospinal fluid flow were assessed using phase-contrast magnetic resonance imaging within the subarachnoid space at the foramen magnum level and the cerebral aqueduct. Results: In the ventral aspect of the subarachnoid space and cerebral aqueduct, the cerebrospinal fluid was characterized by a bidirectional flow throughout the cardiac cycle. The mean ± SD peak velocities through the ventral and dorsal aspects of the subarachnoid space and the cerebral aqueduct were 1.39 ± 0.13, 0.32 ± 0.12, and 0.76 ± 0.43 cm/s, respectively. Conclusions: Noninvasive visualization of cerebrospinal fluid flow movement with magnetic resonance imaging was feasible, and a reference dataset of cerebrospinal fluid flow peak velocities was obtained through the cervical subarachnoid space and cerebral aqueduct in healthy dogs.

• Journal of Forest and Environmental Science
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• v.39 no.2
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• pp.81-95
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• 2023

Due to the multiple ecosystem benefits that iconic large, old growth trees provide, forest managers are applying thinning treatments around these legacy trees to improve their vigor and reduce mortality, especially in the face of climate change and other forest health threats. One objectives of this study was to analyze sub-hourly stem fluctuations of legacy ponderosa (Pinus ponderosa Dougl. Ex P. & C. Laws) and sugar pines (Pinus lambertiana Dougl.) in the mixed-conifer forests of the Sierra Nevada in multiple different radius thinning treatments to assess the short-term effects of these treatments. Thinning treatments applied were: R30C0 (9.1 m radius), R30C2 (9.1 m radius leaving 2 competitors), and RD1.2 (radius equaling DBH multiplied by 1 ft/in multiplied by 1.25). The other objective was to assess climatic drivers of hourly stem fluctuations. Using the dendrometeR package, we gathered daily statistics (i.e. daily amplitude) of the stem fluctuations, as well as stem cycle statistics such as duration and magnitude of contraction, expansion, and stem radial increment. We then performed correlation analyses to assess the climatic drivers of stem fluctuations and to determine which radial thinning treatment was most effective at improving growth. We found an important role that mean solar radiation, air temperature, and relative humidity play in stem variations of both species. One of the main findings from a management perspective was that the RD1.2 treatment group allowed both species to contract less on warmer and higher solar radiation days. Furthermore, sugar pine put on more stem radial increment on higher solar radiation days. These findings suggest that the extended radius RD1.2 thinning treatment may be the most effective at releasing legacy sugar and ponderosa pine trees compared to the other forest management treatments applied.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.6
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• pp.533-540
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• 2000

Gonadal development, gametogenesis, reproductive cycle, gonad index, flesh weight rate, and first sexual maturity of the turban shell, Lunella coronata coreensis were investigated by histological observation. The materials used were collected monthly from the rocky intertidal zone of Daehang-ri, Buan-gun, Jeollabuk-do, on the west coast of Korea, from July 1998 to June 1999. Sex of L coronata coreensis was separate. The gonad was widely located in the spirals of the visceral mass buried in the digestive gland. The ovary and testis were composed of a number of oogenic follicles and speymatogenic follicles, respectively. Monthly variations in the gonad index increased from March ($23.86{\pm}3.73$) when the water temperature increased and reached the maximun in July ($49.76{\pm}6.47$). And then, the gonad index sharply decreased in September ($15.58{\pm}2.33$). The flesh weight rate ranged from $25.2{\%}$ to $32.3{\%}$, and its variation showed a similar pattern to the gonad index. Individuals $<5.9 mm$ in shell height could not take part in reproduction in both sexes. Percentages of first sexual maturity of female and male specimens ranging from $7.0{\~}7.9 mm$ in shell heights were $84.6{\%}\;and\;91.7{\%}$, respectively, and $100{\%}$ in those over 8.0 mm in shell height in both sexes took part in reproduction. By studying the monthly changes of the morphological features and sizes of germ cells during gametogenesis in the gonad, the reproductive cycle of this species could be devided into five successive stages: early active (December to April), late active (January to July), ripe (May to August), spawning (July to September), and recovery (September to March). The spawning period of this species was once a year between July and September, and the main spawning occurred in July when the seawater temperature reached above $24.8^{\circ}C$. The fully ripe eggs were $150{\~}160\;{\mu}m$ in diameter.

• Proceedings of the Mineralogical Society of Korea Conference
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• 2001.06a
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• pp.38-39
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• 2001

The seasonal changes in pH, Fe, Al and SO$_4$$\^$2-/ contents of acid drainage released from coal mine dumps play a major role in precipitation of metal hydroxides in the Taebaek coal field area, southeastern Korea. Precipitates in the creeks underwent a cycle of the color change showing white, reddish brown and brownish yellow, which depends on geochemical factors of the creek waters. White precipitates consist of Al-sulfate (basaluminite and hydrobasaluminite) and reddish brown ones are composed of ferrihydrite and brownish yellow ones are of schwertmannite. Goethite coprecipitates with ferrihydrite and schwertmannite. Ferrihydrite formed at higher values than pH 5.3 and schwertmannite precipitated below pH 4.3, and goethite formed at the intermediate pH range between the two minerals. With the pH being increased from acid to intermediate regions, Fe is present both as schwertmannite and goethite. From the present observation, the most favorable pH that basauluminte can precipitate is in the range of pH 4.45-5.95. SEM examination of precipitates at stream bottom shows that they basically consist of agglomerates of spheroid and rod-shape bacteria. Bacteria species are remarkably different among bottom precipitates and, to a less extent, there are slightly different chemical compositions even within the same bacteria. The speciation and calculation of the mineral saturation index were made using MINTEQA2. In waters associated with yellowish brown precipitates mainly composed of schwertmannite, So$_4$ species is mostly free So$_4$$\^$2-/ ion with less AlSo$_4$$\^$+/, CaSo$\sub$(aq)/, and MgSo$\sub$4(aq)/. Ferrous iron is present mostly as free Fe$\^$2+/, and FeSo$\sub$4(aq)/ and ferric iron exists predominantly as Fe(OH)$_2$$\^$+/, with less FeSo$\sub$4(aq)/, Fe(OH)$_2$$\^$-/, FeSo$_4$$\^$-/ and Fe$\^$3+/, respectively Al exists as free Al$\^$3+/, AlOH$_2$$\^$-/, (AlSo$_4$)$\^$+/, and Al(So$_4$)$\^$2-/. Fe is generally saturated with respect to hematite, magnetite, and goethite, with nearly saturation with lepidocrocite. Aluminum and sulfate are supersaturated with respect to predominant alunite and less jubanite, and they approach a saturation state with respect to diaspore, gibbsite, boehmite and gypsum. In the case of waters associated with whitish precipitates mainly composed of basaluminite, Al is present as predominant Al$\^$3+/ and Al(SO$_4$)$\^$+/, with less Al(OH)$\^$2+/, Al(OH)$_2$$\^$+/ and Al(SO$_4$)$\^$2-/. According to calculation for the mineral saturation, aluminum and sulfate are greatly supersaturated with respect to basaluminite and alunite. Diaspore is flirty well supersaturated while jubanite, gibbsite, and boehmite are already supersaturated, and gypsum approaches its saturation state. The observation that the only mineral phase we can easily detect in the whitish precipitate is basaluminite suggests that growth rate of alunite is much slower than that of basaluminite. Neutralization of acid mine drainage due to the dilution caused by the dilution effect due to mixing of unpolluted waters prevails over the buffering effect by the dissolution of carbonate or aluminosilicates. The main factors to affect color change are variations in aqueous geochemistry, which are controlled by dilution effect due to rainfall, water mixng from adjacent creeks, and the extent to which water-rock interaction takes place with seasons. pH, Fe, Al and SO$_4$ contents of the creek water are the most important factors leading to color changes in the precipitates. A geochemical cycle showing color variations in the precipitates provides the potential control on acid mine drainage and can be applied as a reclamation tool in a temperate region with four seasons.

• Korean Journal of Ichthyology
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• v.19 no.4
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• pp.306-317
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• 2007

Reproductive cycle with the gonad developmental phases, first sexual maturity, spawning frequency, sex ratio of the dusky mud hopper, Periophthalmus modestus were investigated by histological observations. Monthly variations of the gonadosomatic index (GSI) began to increase in May and reached a maximum in June when the gonad was getting mature during the period of higher ground (water) temperature-long day length. Changes in the GSI showed a negative correlation to the HSI, but coincided with the fatness index. The reproductive cycle can be classified into five successive stages: in female, early growing stage (April to May), late growing stage (April to May), mature stage (May to June), ripe and spent stage (June to August), and recovery and resting stage (August to March); in males, growing stage (April to May), mature stage (May to June), ripe and spent stage (June to August), and recovery and resting stage (August to March); According to the frequency distributions of egg diameters during the breeding season, Periophthalmus modestus is presumed to be a summer breeder, asynchronous group and polycyclic species to spawn 2 times or more during the spawning season. Total eggs and mature eggs in absolute fecundity and relative fecundity (per cm) increased with the increase of body length. Total eggs and mature eggs in absolute fecundity and relative fecundity (per g) did not increase with the increase of body weight. Percentages of first sexual maturity of females and males ranging from 5.1 to 5.5 cm in body length are over 50%, and 100% for fish over 7.1 cm in body length. The sex ratios of females to males over 5.1 cm in body length were not significantly different from a 1 : 1 sex ratio.