• 제목/요약/키워드: neutral variation

검색결과 198건 처리시간 0.031초

대기 경계층 연직방향 확산의 지면 거칠기에 따른 변화에 관한 실험적 연구 (An Experimental Study on the Variation of Vertical Dispersion within Boundary Layer with Surface Roughness)

  • 박옥현;윤창옥
    • 한국대기환경학회지
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    • 제16권3호
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    • pp.237-246
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    • 2000
  • An experimental study has been carried out using a rotating water channel in order to investigate the effect of surface roughness on the vertical dispersion of plume within boundary layer. Dispersion measurements of tracers released from two sources with different height at neutral conditions over various rough terrain ranging from rural to urban have been performed. Various values of roughness length were simulated by combining of 4 stream velocities and 3 roughness element conditions. Dispersion measurements have also been made for rough terrain where high buildings are locally concentrated. Values of $\sigma$z increase with roughness and this tendency appears to apply both cases of with and without locally concentrated high buildings. The comparisons of the Bowne's nomogram on $\sigma$2 vs x relationship and the measurements of $\sigma$2 with roughness show good accordance in $\sigma$2 distribution at stability D class over rural, suburban and urban terrain. For constant roughness length the $\sigma$2 values of plumes from lower source height are smaller than those of plumes from higher source at short downwind distance, but this relationship becomes reverse as distance increases. Crossing appears to be made before about 2km. The value of constant I in McMullen's equation $\sigma$2=exp [I+J(In x) + K(In x)2] appears to increase with roughness length, however, the relationships between other constants and roughness have been confirmed. The values of $\sigma$2 for various downwind distances, estimated by using an equation which is employed in ISC (Industrial Source Complex) dispersion model for areas where high buildings are locally assembled, are in accordance with measurements from water channel experiments.

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Seasonal Characteristics of the Longitudinal Wavenumber-4 Structure in the Equatorial Ionospheric Anomaly

  • Kim, E.;Jee, G.;Kim, Y.H.
    • Journal of Astronomy and Space Sciences
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    • 제25권4호
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    • pp.335-346
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    • 2008
  • Using the global total electron contents (TEC) measured by the TOPEX satellite from Aug. 1992 to Oct. 2005, we investigate the variations of the longitudinal wavenumber-4 (LW-4) structure in the equatorial anomaly (EA) crests with season, local time, and solar activity. Our study shows that the LW-4 structure in the EA crests ($5{\sim}20^{\circ}$ MLAT in both hemispheres) has clear four peaks at fixed longitude sectors during the daytime for both equinoxes and June solstice. In spite of being called a wavelike structure, however, the magnitudes and spatial intervals of the four peaks are far from being the same or regular. After sunset, the four-peak structure begins to move eastward with gradual weakening in its amplitude during equinoxes and this weakening proceeds much faster during June solstice. Interestingly, the longitudinal variations during December solstice do not show clear four-peak structure. All these features of the LW-4 structure are almost the same for both low and high solar activity conditions although the ion densities are greatly enhanced from low to high solar activities. With the irrelevancy of the magnetic activity in the LW-4, this implies that the large changes of the upper atmospheric ion densities, one of the important factors for ion-neutral interactions, have little effect on the formation of the LW-4 structure. On the other hand, we found that the monthly variation of the LW-4 is remarkably similar to that of the zonal component of wavenumber-3 diurnal tides at low latitudes, which implies that the lower atmospheric tidal forcing, transferred to the upper atmosphere, seems to have a dominant role in producing the LW-4 structure in the EA crests via the E-region dynamo.

채취시기별 방사무늬김(Porphyra yezoensis)의 식이섬유, 아미노산 및 지방산 함량 변화 (Seasonal Variation in the Dietary Fiber, Amino Acid and Fatty Acid Contents of Porphyra yezoensis)

  • 신동민;안세라;인서경;구재근
    • 한국수산과학회지
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    • 제46권4호
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    • pp.337-342
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    • 2013
  • Porphyra yezoensis is potentially an excellent source of dietary fiber, amino acids, and eicosapentaenoic acid (EPA) because this red seaweed is available in large quantities and is rich in polysaccharides, proteins, and n-3 fatty acids. This study determined the insoluble dietary fiber (IDF), soluble dietary fiber (SDF), neutral detergent fiber (NDF), acid detergent fiber (ADF), amino acid, and fatty acid contents of P. yezoensis harvested monthly from November 2011 to March 2012. The total dietary fiber (TDF) and IDF contents ranged from 27.2-34.9% and 18.5-26.9%, respectively, and were greater in March than November. The SDF content ranged from 4.9-8.4% and did not differ significantly during growth. Galactose and 3,6-anhydro galactose were the major sugars in IDF and SDF. The higher levels of galactose and 3,6-anhydro galactose in IDF might be due to associated porphyran-type polysaccharides. Mannose and xylose were also major sugars in IDF. The total amino acid contents decreased gradually from November to March. The total amino acid composition of Porphyra was dominated by alanine, glutamic acid, arginine, and aspartic acid. No significant changes in the fatty acid profile were observed throughout the study period. The dominant fatty acid during all seasons was EPA, which comprised as much as 50% of the total fatty acid content.

Cellular Biomarker of Membrane Stability and Hydrolytic Enzyme Activity in the Hemocytes of Benzo(a)pyrene-exposed Pacific oyster, Crassostrea gigas

  • Jo Qtae;Choy Eun-Jung;Park Doo Won;Jee Young-Ju;Kim Sung Yeon;Kim Yoon
    • Fisheries and Aquatic Sciences
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    • 제5권4호
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    • pp.263-270
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    • 2002
  • The Pacific oysters, Crassostrea gigas, were stressed with different concentrations of benzo(a) pyrene and depurated to determine the hemocyte lysosomal membrane stability and hydrolytic enzymatic activity as a biomarker candidate to the chemical, using NRR (neutral red retention) and API ZYM System, respectively. The membrane damage measured as NRR decrease was significant with the increase of chemical concentration and exposure time (P<0.05), providing a possible tool for biomarker. Interestingly, the control showed intrinsic stress probably due to captive life in the laboratory, and a recovering trend was also found during the depuration. The benzo(a)pyrene-exposed oysters showed increased enzyme activities in alkaline phosphatase, esterase (C4), acid phosphatase, naphthol-AS-BI-phospho­hydrolase, $\beta$-galactosidase, $\beta$-glucuronidase, and N-acetyl- $\beta$-glucosaminidase. Of them, only two enzymes, acid phosphatase and alkaline phosphatase, showed some potential available for the generation of enzymatic biomarker in the oyster. The results are suggestive of the potential availability of the cellular and enzymatic properties as a biomarker. However, considering that a robust biomarker should be insensitive to natural stress coming from normal physiological variation, but sensitive to pollutants, a concept of intrinsic stress the animal possesses should be taken into consideration. This reflects the necessity of further research on the intrinsic stress affecting the cellular and enzymatic properties of the chemical­stressed oysters prior to using the data as a biomarker.

Variations in Stroke Patients' Muscle Activity during Head Rotation in Non-Paretic-Side Weight Bearing

  • Lee, Kwan-Sub;Choe, Han-Seong;Lee, Byung-Joo
    • The Journal of Korean Physical Therapy
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    • 제27권3호
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    • pp.159-163
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    • 2015
  • Purpose: This study aimed to determine the interaction among the neck, trunk, and lower extremities on the non-paretic side in head rotation along with non-paretic-side weight shifting of stroke patients. To compare stroke patients' ability to control posture through muscle activity variation related to pertubation during head rotation along with the non-paretic limb. Methods: We tested 15 hemiplegic patients and 15 normal individuals. Each group's muscle activity was measured by electromyography in neutral head position and head rotation position. We compared each group's resu lt based on measured values in patients' non-paretic neck muscles, trunk muscles, and lower limbs muscles activation. Results: The study showed that muscle activity increased in the sternocleidomastoid muscle (102.26%, 53.00%), splenius capitis muscle (97.93%, 54.93%), erector spinae muscle (241.00%, 127.60%), external oblique abdominal muscle (256.66%, 152.00%), and internal oblique abdominal muscle (252.80%, 152.6%), peroneus longus muscle (117.53%, 137.13%) and gastrocnemius muscle (119.06%, 137.20%), while the results for the sternocleidomastoid muscle, splenius capitis muscle, erector spinae muscle, external oblique abdominal muscle, internal oblique abdominal muscle, peroneus longus muscle, and gastrocnemius muscle showed a statistically significant difference (p<0.05). Conclusion: It is hard for stroke patients to engage in normal movement control under suggested conditions because of the insufficient movement against gravity on the stroke patient's non-paretic side and impaired cooperative patterns. To solve these problems, patients need their bodies to improve through effective movement, resulting in advanced control of their effective and functional activity.

Intra- and inter-rater reliability of muscle thickness measurement of the tibialis anterior using different inward pressures

  • Lee, Seong-Joo;Lim, Ji Young;Lee, Chang-Hyung;Park, Dae-Sung
    • Physical Therapy Rehabilitation Science
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    • 제8권4호
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    • pp.218-224
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    • 2019
  • Objective: This reliability study examined the effects of applying varying induced inward pressures using a transducer placed at 0° neutral ankle position (NEU) and 15° ankle dorsiflexion (DF) on tibialis anterior (TA) muscle thickness using a custom-made device with a force indicator during rehabilitative ultrasound imaging. Design: Cross-sectional study. Methods: Twenty-four healthy subjects were recruited in this study. Two examiners measured the muscle thickness of the TA at 0° NEU and 15° DF in 3 conditions of inward pressures (1.0 N, 2.0 N, and 4.0 N) using a custom-made holder. The muscle thickness was measured three times for each of the conditions arranged in random order. For intra- and inter-rater reliability, the intraclass correlation coefficients (ICCs) with 95% confidence intervals, standard error of measurement, minimal detectable change, and coefficient of variation were analyzed. One-way repeated measures analysis of variance was conducted for investigating changes of TA muscle thickness according to the inward pressures of the transducers. Results: The intra-rater reliability of TA muscle thickness measurement was excellent (ICC3,1: 0.92-0.96) for all conditions (at both ankle joint angles per varying inward pressure). Likewise, the inter-rater reliability of TA muscle thickness measurement was excellent (ICC2,1: 0.89-0.97) under same conditions. The mean of TA thickness showed the trend of decreasing significantly with increased inward pressures at all ankle joint angles (p<0.05). Conclusions: Use of this custom-made device with a force indicator is useful to accomplish the high intra- and inter-rater reliability of TA muscle thickness measurement at both ankle joint angles in reducing the measurement error.

물 재이용을 위한 하수처리장 방류수 색도의 자외선처리에 미치는 과산화수소의 영향 (Effect of Hydrogen Peroxide on UV Treatment of Color in Secondary Effluent for Reclamation)

  • 박기영;맹승규;김기팔;이석헌;권지향;안규홍
    • 상하수도학회지
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    • 제18권3호
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    • pp.377-384
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    • 2004
  • In the present study, a feasibility of an advanced oxidation process using UV/Hydrogen peroxide($H_2O_2$) system equipped with a medium pressure lamp for secondary effluent reclamation was investigated. Initial concentration of $H_2O_2$ and pH were changed to determine the optimum operation condition for the system. The removal efficiency of color was than 80% with 14.3mg/L of initial $H_2O_2$ and 5 minute of contact time in the UV/$H_2O_2$ system. The color removal was analyzed using first-order reaction equation. The dependence of rate constant (k) on initial $H_2O_2$ represented the rational relationship with maximum value. Residual $H_2O_2$ caused increase of effluent COD, since analyzing agent, dichromate, reacted with $H_2O_2$ in the sample. Therefore, excess initial concentration of $H_2O_2$ would significantly affect effluent COD measurement. At pH variation experiment, both residual $H_2O_2$ and color showed peak in the neutral pH range with the same pattern. Effect of $H_2O_2$ dose also enhanced color removal but raised residual $H_2O_2$ problem in the continuous operation UV system. In conclusion, these results indicated that medium pressure UV/$H_2O_2$ system could be used to control color in the secondary effluent for reclamation and reuse.

인테리어 직물색채의 트랜드변화 특성에 관한 연구 (A Study on the Characteristics of Color trend for Interior textile)

  • 박소영;박영순
    • 한국실내디자인학회논문집
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    • 제23호
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    • pp.109-115
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    • 2000
  • The purpose of this study is to examine the interior textile color changes and trends by analyzing the characteristics of interior color hues and tones. Heimtextil in the interior field was selected for color trend analysis from 1996 to 2000. The conclusions of this study are as follows: First, In terms of hue, warm colors like Y, YR, and R were most prominent in all four years. Some new colors, however, emerged with higher frequency. The frequency of GY and B increased in 96/97, GY, BG and PB in 97/98 PB and B in 98/99, and B and PB in 99/2000. Especially between 96/2000, the frequency of PB and B has been increased, although the frequency of GY has been decreased. Over the four years, P, RP, and Neutral showed medium frequency, and G and BG showed low frequency. Gold appeared as an accent color in two years while silver appeared in one year. In summary, warm colors like Y, YR, and R were most prominent in interior color. Second, In terms of tone, p, b, v, and sf were most prominent over the four years. Although 에 and ltg appeared with high frequency n general, a wide variation was presented. The tones such as p, dp, and v appeared with high frequency in the three years of 96/97, 97/98 b and sf in 97/98 ; lt, dk and sf in 98/99. On the other hand, a new trend emerged in 99/2000. In this year, ltg, sf, s, d and dkg appeared with high frequency unlike the other three years. In other words, soft or light tones, such as pale, soft, light, grayish, and deep, and strong tones, such as vivid and bright, appeared with high frequency.

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Chemical Composition, Phenolic Concentration and In Vitro Gas Production Characteristics of Selected Acacia Fruits and Leaves

  • Abdulrazak, S.A.;Orden, E.A.;Ichinohe, T.;Fujihara, T.
    • Asian-Australasian Journal of Animal Sciences
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    • 제13권7호
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    • pp.935-940
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    • 2000
  • The objective of this study was to evaluate the nutritive value of selected fruits (pods and seeds) and leaves of acacia tree species namely; Acacia nubica (nubica), Acacia tortilis (tortilis) and Acacia brevispica (brevispica), Acacia reficiens (reficiens) and Acacia senegal (senegal). A wide variability in chemical composition, polyphenolics and gas production was recorded. The crude protein (CP) ranged from 131 to 238 g/kg DM. Neutral detergent fiber (NDF), acid detergent fiber (ADF) and lignin (ADL) were higher in senegal and significantly different (p<0.05) from other species. The nitrogen bound to fiber tended to be higher in leaves than the fruits, ranging from 2.6 to 11.3 g/kg NDF and 1.6 to 3.2 g/kg ADF. The leaves of reficiens and senegal had higher concentrations of total extractable phenolics (TEPH), total extractable tannins (TET) and total condensed tannins (TCT), but lower in NDF, ADF and ADL than the fruits of nubica, tortilis and brevispica. Mineral concentrations varied among species; all were relatively poor in phosphorus, moderate in calcium and magnesium, and rich in microelements. A significant (p<0.05) variation in gas production after 12, 24, 48, 72 and 96 h was recorded between species. Nubica had the highest (p<0.05) rate of gas production (0.0925) while the highest potential gas production was recorded in tortilis. A strong negative correlation between TEPH and TET with gas production after 24, 48, 72 and 96 was established (r=-0.72 to -0.82). Crude protein and TCT correlated negatively but also weakly with gas production characteristics. Organic matter digestibility calculated from gas production after 48 h (OMD48) ranged between 465 g/kg DM in reficiens and 611 g/kg DM in tortilis. The results of this study indicate that acacia species have the potential to be used as feed supplements.

Variability in Ash, Crude Protein, Detergent Fiber and Mineral Content of Some Minor Plant Species Collected From Pastures Grazed by Goats

  • Serra, A.B.;Serra, S.D.;Orden, E.A.;Cruz, L.C.;Nakamura, K.;Fujihara, T.
    • Asian-Australasian Journal of Animal Sciences
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    • 제10권1호
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    • pp.28-34
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    • 1997
  • This study was conducted to determine the protein content, cell wall fractions, and mineral concentrations of some minor plant species collected for one year in pastures grazed by goats in the Philippines. An assessment of nutrient variability and a comparison of forage protein and mineral concentrations to the critical value of protein and minerals based on animal needs were also studied. The plant species were the following: grasses(Axonopus compressus, Eleusine indica, Rottboellia exaltata); legumes (Aeschynomene indica, Calopogonium muconoides, Desmodium tortousum); and herbs (Corchorus olitorius, Ipomea aquatica, Sida acuta, Synedrella nodiflora). The two seasons (dry and wet) were subdivided into Dry-1 (December to February, 132 mm total rainfall), Dry-2 (March to May, 25 mm total rainfall), Wet-1 (June to August, 1,138 mm total rainfall), and Wet-2 (September to November, 1,118 mm total rainfall). Results showed that significant differences were obtained on various nutrient fractions including those mineral concentrations across species. Across season, acid detergent lignin (ADL) had higher (p < 0.05) value at Dry-1. Legumes and herbs were higher in crude protein (CP) especially Sida acuta. Grasses showed the highest neutral detergent fiber (NDF) and acid detergent fiber (ADF) with the addition of Sida nodiflora (herb) for it contained high NDF. Aeschynomene indica contained the highest amount of ADL and the herbs (Ipomea aquatica and Sida acuta) had exceptionally high concentration of minerals. Coefficient variation of the various nutrient values ranged from 27.3 to 136.7%. Some forage minerals appeared to be deficient (sodium, phosphorus and copper) or excess (molybdenum) for the whole or part of the year. This study shows that some minor plant species could extend the range of concentration of some nutrients (i.e., CP and minerals) beyond that normally found in conventional pasture species.