• Title/Summary/Keyword: growth velocity

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Improving Adherence to Growth Hormone (GH) Therapy via EasypodTM May Help Maximize the Treatment Outcome

  • Choi, Hae-Jeong
    • Journal of mucopolysaccharidosis and rare diseases
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    • v.1 no.1
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    • pp.19-22
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    • 2015
  • In Growth Hormone (GH) therapy, suboptimal adherence is a common problem, reaching up to 82%, and there is a need for interventions to improve adherence and to maximize patients' growth potential eventually. Current studies have demonstrated the association between the rate of non-adherence and reduced height velocity. In order to maximize patients' potential to grow, an auto-injecting/recording device, such as $easypod^{TM}$, may help improve adherence and optimize the treatment effects of GH therapy. The use of $easypod^{TM}$ has contributed to high adherence rates: 87.5% and 93% in Bozzola et al.'s study and the $Easypod^{TM}$ Connect Observational study (ECOS), respectively. Improvement of adherence by $easypod^{TM}$ may lead to higher growth rates of patients receiving GH therapy. Additionally, patients' positive acceptability of $easypod^{TM}$ suggests $easypod^{TM}$ is a preferred device by patients for better adherence.

Numerical Analysis for the Detailed Structure and the Soot Formation Mechanism in Counterflow Ethylene-Air Nonpremixed Flame (대향류 에틸렌/공기 비예혼합 화염의 구조 및 Soot 생성 메커니즘 해석)

  • 임효준;김후중;김용모
    • Transactions of the Korean Society of Automotive Engineers
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    • v.7 no.5
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    • pp.40-54
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    • 1999
  • The flame structure and soot formation in the counterflow Ethylene-Air nonpremixed flame are numerically analyzed. The present soot reaction mechanism involves nucleation, surface growth, particle coagulation, and oxidation steps. The gas phase chemistry and the soot nucleation, surface growth reactions are coupled by assuming that the nucleation and soot mass growth has the certain relationship with the concentration of benzene and acetylene. In terms of the centerline velocity and the soot volume fraction, the predicted results are compared with the experimental data. The detailed discussion has been made for the sensitivity of model constants and the deficiencies of the present model. Numerical results indicated that the acetylene addition to the soot surface plays the dominant role in the soot mass growth for the counterflow nonpremixed flame.

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Effects of Gas Flow Variables on the Crystal Growth of Diamond in Hot Filament-Assisted CVD (고온 필라멘트 다이아몬드 CVD에서 기체유동변수가 결정성장에 미치는 영향)

  • 서문규;이지화
    • Journal of the Korean Ceramic Society
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    • v.31 no.1
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    • pp.88-96
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    • 1994
  • Hot filament-assisted CVD was carried out to deposit diamond films on Si(100) substrate at 90$0^{\circ}C$ using a 1% CH4-H2 mixture gas. Deposition was made at various conditions of mass flow rate of the feed gas (30~1000 sccm), pressure (2.5~300 Torr), and filament-substrate distance (4~15 mm), and the deposited films were characterized by SEM, XRD, and Raman spectroscopy. As the flow rate increases, the growth rate also increased but the crystallinity of the film was degraded. A longer filament-substrate distance simply caused both the growth rate and the crystallinity to become poorer. On the other hand, the pressure variation resulted in a maximum growth rate of 2.6 ${\mu}{\textrm}{m}$/hr at 10 Torr and the best film quality around 50 Torr, exhibiting an optimum condition. The observed trends were interpreted in terms of the flow velocity-dependent pyrolysis reaction efficiency and mass transport through the boundary layer.

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Study on simultaneous heat and mass transfer during the physical vapor transport of Hg2Br2 under ㎍ conditions

  • Kim, Geug Tae
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.29 no.3
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    • pp.107-114
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    • 2019
  • A computational analysis has been carried out to get a thorough and full understanding on the effects of convective process parameters on double-diffusive convection during the growth of mercurous bromide ($Hg_2Br_2$) crystals on earth and under ${\mu}g$ conditions. The dimensional maximum magnitude of velocity vector, ${\mid}U{\mid}_{max}$ decreases much drasticlly near Ar = 1, and, then since Ar = 2, decreases. The ${\mu}g$ conditions less than $10^{-2}g$ make the effect of double-diffusion convection much reduced so that adequate advective-diffusion mass transfer could be obtained.

The intrinsic instabilities of fluid flow occured in the melt of Czochralski crystal growth system

  • Yi, Kyung-Woo;Koichi Kakimoto;Minoru Eguchi;Taketoshi Hibiya
    • Proceedings of the Korea Association of Crystal Growth Conference
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    • 1996.06a
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    • pp.179-200
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    • 1996
  • The intrinsic instabilities of fluid flow occurred in the melt of the Czochralski crystal growth system Czochralski method, asymmetric flow patterns and temperature profiles in the melt have been studied by many researchers. The idea that the non-symmetric structure of the growing equipment is responsible for the asymmetric profiles is usually accepted at the first time. However further researches revealed that some intrinsic instabilities not related to the non-symmetric equipment structure in the melt could also appear. Ristorcelli had pointed out that there are many possible causes of instabilities in the melt. The instabilities appears because of the coupling effects of fluid flow and temperature profiles in the melt. Among the instabilities, the B nard type instabilities with no or low crucible rotation rates are analyzed by the visualizing experiments using X-ray radiography and the 3-D numerical simulation in this study. The velocity profiles in the Silicon melt at different crucible rotation rates were measured using X-ray radiography method using tungsten tracers in the melt. The results showed that there exits two types of fluid flow mode. One is axisymmetric flow, the other is asymmetric flow. In the axisymmetric flow, the trajectory of the tracers show torus pattern. However, more exact measurement of the axisymmetrc case shows that this flow field has small non-axisymmetric components of the velocity. When fluid flow is asymmetric, the tracers show random motion from the fixed view point. On the other hand, when the observer rotates to the same velocity of the crucible, the trajectory of the tracer show a rotating motion, the center of the motion is not same the center of the melt. The temperature of a point in the melt were measured using thermocouples with different rotating rates. Measured temperatures oscillated. Such kind of oscillations are also measured by the other researchers. The behavior of temperature oscillations were quite different between at low rotations and at high rotations. Above experimental results means that the fluid flow and temperature profiles in the melt is not symmetric, and then the mode of the asymmetric is changed when rotation rates are changed. To compare with these experimental results, the fluid flow and temperature profiles at no rotation and 8 rpm of crucible rotation rates on the same size of crucible is calculated using a 3-dimensional numerical simulation. A finite different method is adopted for this simulation. 50×30×30 grids are used. The numerical simulation also showed that the velocity and flow profiles are changed when rotation rates change. Futhermore, the flow patterns and temperature profiles of both cases are not axisymmetric even though axisymmetric boundary conditions are used. Several cells appear at no rotation. The cells are formed by the unstable vertical temperature profiles (upper region is colder than lower part) beneath the free surface of the melt. When the temperature profile is combined with density difference (Rayleigh-B nard instability) or surface tension difference (Marangoni-B nard instability) on temperature, cell structures are naturally formed. Both sources of instabilities are coupled to the cell structures in the melt of the Czochralski process. With high rotation rates, the shape of the fluid field is changed to another type of asymmetric profile. Because of the velocity profile, isothermal lines on the plane vertical to the centerline change to elliptic. When the velocity profiles are plotted at the rotating view point, two vortices appear at the both sides of centerline. These vortices seem to be the main reason of the tracer behavior shown in the asymmetric velocity experiment. This profile is quite similar to the profiles created by the baroclinic instability on the rotating annulus. The temperature profiles obtained from the numerical calculations and Fourier transforms of it are quite similar to the results of the experiment. bove esults intend that at least two types of intrinsic instabilities can occur in the melt of Czochralski growing systems. Because the instabilities cause temperature fluctuations in the melt and near the crystal-melt interface, some defects may be generated by them. When the crucible size becomes large, the intensity of the instabilities should increase. Therefore, to produce large single crystals with good quality, the behavior of the intrinsic instabilities in the melt as well as the effects of the instabilities on the defects in the ingot should be studied. As one of the cause of the defects in the large diameter Silicon single crystal grown by the

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Cross-sectional Study of Growth of Korean Breast Fed Formula Fed Infants from 1 to 3 Postpartum Months (모유양양아와 인공영양아의 성장발육 상태에 관한 횡단적 연구)

  • 최경숙;최혜미;정상진;구재옥;임현숙
    • Korean Journal of Community Nutrition
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    • v.2 no.1
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    • pp.3-12
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    • 1997
  • One-to three -month-old infants(n=252) were compared their growth performance(weight, length, head circumference, chest circumference) by feeding methods in cross-sectional study. There were two groups : breast-fed(BF) and formula-fed groups(FF). The weights of infants at 1, 2, and 3 postpartum month were 4.50$\pm$0.48kg, 5.76$\pm$0.62kg and 6.67$\pm$0.68kg, respectively. The weigh of male infants was higher than females. The length were 53.7$\pm$2.6cm, 57.4$\pm$3.3cm, 61.1$\pm$3.1cm at one to three postpartum months, respectively. The length of male infants was higher than females, too. Overall there were no significant differences between feeding methods in weight, length, head and chest circumferences, and monthly weight and length velocity. But 3-month-old formula-fed male infants showed bigger significantly in weight, monthly weight velocity and chest circumference than the breast-feds. By Korean standards, weight-for-height Z-score were distributed from 0 to +2. Not only was there a few malnourished infants but also overnourished were noticed, especially in formula-fed group. From this survey, long-time survey on growth and development of large scales might be necessary to determine the effect of feeding methods of infants after 3 months and to set proper grwoth standard for infant. And it was suggested the that the careful attention of polarized nutritional problems of early infants was needed, especially in formula-fed group. (Korean J Community Nutrition 2(1) : 3~12, 1997)

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A Numerical Study on the Effects of the Wind Velocity and Height of Grassland on the flame Spread Rate of Forest Fires (초지화재 발생시 바람의 속도 및 초본의 높이가 화염전파에 미치는 영향에 대한 수치해석적 연구)

  • Bae, Sung-Yong;Kim, Dong-Hyun;Ryou, Hong-Sun;Lee, Sung-Hyuk
    • Fire Science and Engineering
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    • v.22 no.3
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    • pp.252-257
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    • 2008
  • With the rapid exuberant growth of the forest, the number and size of forest fires and the costs of wildland fires have increased. The flame spread rate of forest fires is depending on the environmental variables like the wind velocity, moisture of grassland, etc. If we know the effects of the environmental variables on the fire growth, it is useful for wildland fiIre suppression. But analysis of the spread rate of wildland fire for these effects have not been established. In this study, the effects of wind velocity and height of grassland fuel have been investigated using the WFDS which is developed at NIST for prediction of the spread of wildland fires. The results showed that the relation between the height of the fuel and the spread rate of the head fires is, and the spread rates related to the wind velocity are predicted 17% less than the experimental results of Australia. When the wind velocity is over 7.5m/s, the concentration of pyrolyzed gas phase fuel is getting low due to fast movement of pyrolyzed gas, the flame spread rate becomes slow.

An Experimental Study on the Direct Contamination Pathway of Elemental iodine Vapor $(I_2)$ for Rice Plants (벼에 대한 원소상 요오드 증기$(I_2)$의 직접오염경로 해석 실험)

  • Choi, Y.H.;Lim, K.M.;Lee, C.M.;Park, H.G.;Park, D.W.;Choi, G.S.;Choi, H.J.;Lee, H.S.;Lee, C.W.
    • Journal of Radiation Protection and Research
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    • v.29 no.3
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    • pp.165-172
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    • 2004
  • Rice plants were exposed to $I_2$ vapor for 80 min at different growth stages in an exposure box to investigate the parameters concerning direct plant contamination. Deposition velocity $(m\;s^{-1})$ of the $I_2$ vapor for the straws was in the range of $1.4{\times}10^{-5}-1.3{\times}10^{-4}$ depending on the exposure time, being comparatively low during the earlier part of the plant growth. Ear deposition velocity was in the range of $2.5{\times}10^{-5}-6.7{\times}10^{-5}$. Whole-plant deposition velocity was in the range of $1.4{\times}10^{-5}-1.8{\times}10^{-4}$ with the highest from the exposure performed on Aug. 18 (7 d after the start of heading). The time-dependent variation generally decreased when the deposition velocity was normalized to the biomass density No noteworthy tendency in the deposition velocity was observed with regard to the temperature, sunlight and humidity. Translocation factor for the hulled seeds was $3.3{\times}10^{-5}-4.7{\times}10^{-4}$ with the highest from the Aug. 23 exposure. It was found that a leaf deposition even before the ear emergence resulted in a considerable seed translocation.

A LONGITUDINAL STUDY ON THE INTERRELATIONSHIP BETWEEN THE GROWTH CHANGE OF THE MANDIBLE AND DEVELOPMENTAL AGE OF GROWING GIRLS (성장기 소녀에서 하악골 성장 변화와 발육 연령의 상호 관계에 대한 누년적 연구)

  • Kim, Young-Joon;Sohn, Byung-Wha
    • The korean journal of orthodontics
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    • v.22 no.3 s.38
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    • pp.603-615
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    • 1992
  • This study was undertaken to investigate the interrelationship between the growth change of mandible and the developmental age of growing girls in the longitudinal data from 7 years to 15 years. The data were obtained from maturation stage of cervical vertebrae through the serial lateral cephalogram, height increment records which was taken at one year interval, menarche date through interview. On the basis of findings of this study, the following conclusions were obtained. 1. In general the growth of mandible (Ar-Pog, Ar-Go, Go-Pog) showed two peaks of growth velocity. 2. The maximum growth of mandible (Ar-Pog, Ar-Go, Go-Pog) almost appeared between stage 3 and stage 4 in maturation of cervical vertebrae. 3. It showed the tendency that the maximum increment of height appeared faster than that of mandible (Ar-Pog, Ar-Go, Pog-Go). 4. The maximum growth of height almost appeared between stage 2 and stage 3 in maturation of cervical vertebrae. 5. It showed the tendency that the menarche appeared later than the maximum growth of mandible (Ar-Pog, Ar-Go, Pog-Go). 6. The menarche almost appeared at stage 4, stage 5 in maturation of cervical vertebrae.

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Experimental Study of Heating Surface Angle Effects on Single Bubble Growth

  • Kim, Jeong-Bae;Kim, Hyung-Dae;Lee, Jang-Ho;Kwon, Young-Chul;Kim, Jeong-Hoon;Kim, Moo-Hwan
    • Journal of Mechanical Science and Technology
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    • v.20 no.11
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    • pp.1980-1992
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    • 2006
  • Nucleate pool boiling experiments were performed using pure R11 for various surface angles under constant heat flux conditions during saturated pool boiling. A 1-mm-diameter circular heater with an artificial cavity in the center that was fabricated using a MEMS technique and a high-speed controller were used to maintain the constant heat flux. Bubble growth images were taken at 5000 frames per second using a high-speed CCD camera. The bubble geometry was obtained from the captured bubble images. The effects of the surface angle on the bubble growth behavior were analyzed for the initial and thermal growth regions using dimensional scales. The parameters that affected the bubble growth behavior were the bubble radius, bubble growth rate, sliding velocity, bubble shape, and advancing and receding contact angles. These phenomena require further analysis for various surface angles and the obtained constant heat flux data provide a good foundation for such future work.