• 제목/요약/키워드: growth balance

Search Result 634, Processing Time 0.021 seconds

Dynamic Free-surface Deformations in Axisymmetric Liquid Bridges

  • Sim B.-C.;Kim W.-S.;Zebib A.
    • 한국전산유체공학회:학술대회논문집
    • /
    • 2003.10a
    • /
    • pp.160-161
    • /
    • 2003
  • Thermocapillary convection is a surface tension driven flow due to a temperature gradient along an interface. It occurs during a crystal-growth process and therefore understanding the convection is important to material processing in microgravity. Although modelling of the float-zone crystal-growth process has been of interest for a few decades, most studies of liquid bridges assumed non-deformable flat surfaces. In reality, the surface profile, g(t,z), is unknown and should be obtained as a solution to the coupled transport equations along with the surface force balance. Here we report on a numerical study of axisymmetric thermocapillary convection in liquid bridges with deformable surfaces. The interface is determined as part of the complete solution. The influence of the capillary number (Ca), Reynolds number (Re), Prandtl number (Pr) and aspect ratio(Ar) on the dynamics is explored.

  • PDF

Nutritional Support Strategies for the Preterm Infant in the Neonatal Intensive Care Unit

  • Hay, William W. Jr.
    • Pediatric Gastroenterology, Hepatology & Nutrition
    • /
    • v.21 no.4
    • /
    • pp.234-247
    • /
    • 2018
  • The goal of nutrition of the preterm infant is to "provide nutrients to approximate the rate of growth and composition of weight gain for a normal fetus of the same postmenstrual age and to maintain normal concentrations of blood and tissue nutrients" (American Academy of Pediatrics 2014). Failure to provide the necessary amounts of all of the essential nutrients to preterm infants has produced not only growth failure, but also increased morbidity and less than optimal neurodevelopment. This continues to be true despite many efforts to increase nutrition of the preterm infants. In contrast, enhanced nutrition of very preterm infants, both intravenous and enteral, beginning right after birth, promotes positive energy and protein balance and improves longer term neurodevelopmental outcomes. The benefits are long lasting too, particularly for prevention of later life chronic diseases.

Start-up dynamics in a CMSMPR crystallizer (CMSMPR 결정화기의 시동 특성 연구)

  • 신영준;이철수
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 1986.10a
    • /
    • pp.200-204
    • /
    • 1986
  • Particle size distribution in a Continuous Mixed Suspension Mixed Crystal Removal (CMSMPR) crystallizer has been analyzed using the Population Balance (PB) model. This method presents difficulties when the growth rate of crystal depends on the crystal size. Recent studies indicate that in many cases the growth rate is dependent on size when the crystal sizes are small. In this study, a Residence Time Distribution(RTD) model was proposed to take the size dependence into account together with an appropriate numerical scheme. When compared with the approximate results based on PB model, RTD model results showed improvements also a nucleation effect which is normally unimportant for steady state analysis. Start-up data for NaCl-Water-Ethanol system was compared with computed values.

  • PDF

Rice growth and Nutrient change in paddy soil with reclaimed sewage irrigation (오수처리수 관개방법에 따른 수도 생육과 토양내 영양물질 변화)

  • 윤춘경;황하선;우선호
    • Magazine of the Korean Society of Agricultural Engineers
    • /
    • v.43 no.6
    • /
    • pp.154-162
    • /
    • 2001
  • This study was performed to examine the rice growth and nutrient change in paddy soil with reclaimed sewage irrigation. Total nitrogen and total phosphorus in the experimental system were analyzed before and after rice culture. The experiment lasted three consecutive years, and this paper presents results of the last year. Additional supply of nutrients to the rice culture by reclaimed sewage irrigation was significant and it increased the yield. Nutrient uptake by rice plant increased with more nutrient supplied, however. there was limit in plant uptake. Nutrient accumulation occurred in the soil and it was more apparent for the phosphorus where most of the remaining quantity was accumulated while substantial amount of nitrogen was lost during the growing season. This study suggested that additional nutrient supply by reclaimed sewage irrigation might be a supplemental benefit to the rice culture, and it can help the fertilization management. However, long term effects of continual reclaimed sewage irrigation should be assessed carefully including nutrient mass balance in the paddy rice culture system.

  • PDF

The Forecasting Model of the Change in Food Balance and Nutrient Intake under the Economic Growth (경제성장에 따른 식품수급 및 영양소 섭취 변화의 예측 모형)

  • Lee, Jong-Mee
    • Journal of the Korean Society of Food Culture
    • /
    • v.5 no.4
    • /
    • pp.481-485
    • /
    • 1990
  • This study is designed to forecast the characteristics in food consumption patterns under per capita GNP growth. Ordinary least square(OLS)method was employed as analyzing technique. Equation was $Y=a_0+a_1X$, in which X was per capita GNP and Y were Engel coefficient, food supply, energy supply, nutrient intake and ratio of self-supply of food. The result obtained indicates that the intake of nutrient such as protein and fat will be increased, and wheat, corn and legume are expected to be imported wholly due to lower ratio of self-supply, and rice will be over-supplied continually. Therefore, the relevant policy of government must be established in the field of supply and demand of food, and the research of sound national health should be done.

  • PDF

Technological Trend of Crystallization Research for Bioproduct Separation (Bioproduct 분리를 위한 결정화 연구 동향)

  • Kim, Woo-Sik;Lee, Eun-Kyu
    • KSBB Journal
    • /
    • v.20 no.3
    • /
    • pp.164-176
    • /
    • 2005
  • In bioengineering field, current academic trends and informations on crystallization technology for bioproduct separation were summarized. It is essential for utilizing the crystallization technology to understand the fundamental phenomena of crystallization of crystal nucleation, crystal growth, crystal agglomeration and population balance for the design of crystallizers. In general, the crystal nucleation that the crystalline solids occur from the solution is analyzed by Gibb's free energy change in the aspect of thermodynamics and in the present paper the crystal nucleation models based on the above thermodynamics are summarized by their key characteristics. The crystal growth and agglomeration, which have been studied over 50 years and are essential phenomena for separation technology, are reviewed from their basic concept to most leading edge trend of researches. In the material and population balances for the designs of crystallization separation process, the analysis of crystallizers is summarized. Thereon, the present review paper will academically contribute the understanding the crystallization phenomena and the design of the crystallization separation process.

Development of a Novel Yeast Strain Which Ferments Soy Sauce by Protoplast Fusion

  • Lee, Eun-Ju;Kim, Jong-Kyu
    • Journal of Microbiology and Biotechnology
    • /
    • v.3 no.1
    • /
    • pp.24-30
    • /
    • 1993
  • In order to develop a novel yeast which produces the charateristic aroma of soy sauce, a protoplast fusion between Zygosaccharomyces rouxii WFS4 and Torulopsis versatilis IAM 4993 was carried out. Auxotrophic mutants as selective markers were obtained from Zygosaccharomyces rouxii and Torulopsis versatilis by treatment of N-methyl-N -nitro-N-nitrosoguanidine. The conditions of the protoplast formation and the regeneration for fusion were examined. The protoplast fusion using polyethylene glycol 4000 led to the fusion frequency of $4~5{\times}10^{-7}\;cells/ml$. Among fusants, a fusant ST723-F31 presented the best results in terms of the aromaticity of fragrance, the growth pattern, the resistance against salt and the degree of growth according to pH. It makes easy to control the production and the balance of aroma components so that it gives a good flavor, shortens the fermentation period and, simplifies the preparation process when using a bioreactor into which fusant is immobilized.

  • PDF

Roles of YehZ, a Putative Osmoprotectant Transporter, in Tempering Growth of Salmonella enterica serovar Typhimurium

  • Kim, Seul I;Ryu, Sangryeol;Yoon, Hyunjin
    • Journal of Microbiology and Biotechnology
    • /
    • v.23 no.11
    • /
    • pp.1560-1568
    • /
    • 2013
  • Salmonella, a main cause of foodborne diseases, encounters a variety of environmental stresses and overcomes the stresses by multiple resistance strategies. One of the general responses to hyperosmotic stress is to import or produce compatible solutes so that cells maintain fluid balance and protect proteins and lipids from denaturation. The ProP and ProU systems are the main transport systems for compatible solutes. The OsmU system, recently identified as a third osmoprotectant transport system, debilitates excessive growth as well by reducing production of trehalose. We studied a fourth putative osmoprotectant transport system, YehZYXW, with high sequence similarity with the OsmU system. A Salmonella strain lacking YehZ, a predicted substrate-binding protein, did not suffer from hyperosmolarity but rather grew more rapidly than the wild type regardless of glycine betaine, an osmoprotectant, suggesting that the YehZYXW system controls bacterial growth irrespective of transporting glycine betaine. However, the growth advantage of ${\Delta}yehZ$ was not attributable to an increase in OtsBA-mediated trehalose production, which is responsible for the outcompetition of the ${\Delta}osmU$ strain. Overexpressed YehZ in trans was capable of deaccelerating bacterial growth vice versa, supporting a role of YehZ in dampening growth. The expression of yehZ was increased in response to nutrient starvation, acidic pH, and the presence of glycine betaine under hyperosmotic stress. Identifying substrates for YehZ will help decipher the role of the YehZYXW system in regulating bacterial growth in response to environmental cues.

Study on the Utilization of Festulolium braunii for the Development of NewForage Resources (새로운 사초자원 개발을 위한 Festulolium braunii의 이용에 관한 연구)

  • ;H. Jacob
    • Journal of The Korean Society of Grassland and Forage Science
    • /
    • v.16 no.1
    • /
    • pp.27-38
    • /
    • 1996
  • This study was conducted to evaluate the potential of Festulolium braunii(Festuca pratensis Huds. $\times$ Loliurn mulrijZorum Lam.)as forge sources. The experiment was arranged in a split plot design with four replications from Feb. 1995. to Jan. 1996 at Hohenheim university. Main plots consisted of three forage species, Festulolirtrn braunii(Paulita), Lolium multiJomm(Lemtla), and Secale cereale(Halo) and subplots consisted of three maturity, boot, heading, and anthesis. The growth characteristics, DM yields, nutritive value, N and energy balance were observed. The heading date of Festulolium braunii was about two days earlier than that of Loliunz mrtltiflorum, farthermore Fesrulolium braunii retained higher leaf weight ratio(LWR) than other species. Festulolium brarrnii failed to show any significant differences in grass length, number of tillers, LAI, CGR, and DM accumulation when harvested at the same stage of maturity as compare with Loliurn mulriiflorutn or Setale cerede, bur the content of CP, OMD, and mineral elements and NEL value of Festulolium braunii compare to othes were slightly increased(P<0.05), while the content of NDF, ADF, and lignin decreased(P<0.05). The yield of CP was greater for Festulolium braunii than for Lolium multfimm and yields of DOM and NEL per unit area(ha) for Festulolium braunii were greater than for other species(P<0.05). The equivalent or higher DM production and nutritive value are obtained when Festulolium braunii are cut during the period from boot to anthesis stages, therefor DM intake, preference, and N and energy balance were also higher for Festulolirtm braunii compare to for other species. It could be suggested that Lolium multrfirum would be a more suitable substitute to Festuloliron braunii without decreasing forage production and quality, but the substitutive effect of Secale cereale would be difficult because of the maor differences in growth type and period compare to Fesrulolium braunii. From above the results of this experiment it appears that Festulolium braunii have a potential to provide forage sources. but funher research is needed to ascertain their potential under the climate of Korea.

  • PDF

A Study on Financial Ratio and Prediction of Financial Distress in Financial Markets

  • Lee, Bo-Hyung;Lee, Sang-Ho
    • Journal of Distribution Science
    • /
    • v.16 no.11
    • /
    • pp.21-27
    • /
    • 2018
  • Purpose - This study investigates the financial ratio of savings banks and the effect of the ratio having influence upon bankruptcy by quantitative empirical analysis of forecast model to give material of better management and objective evidence of management strategy and way of advancement and risk control. Research design, data, and methodology - The author added two growth indexes, three fluidity indexes, five profitability indexes, and four activity indexes CAMEL rating to not only the balance sheets but also the income statement of thirty savings banks that suspended business from 2011 to 2015 and collected fourteen financial ratio indexes. IBMSPSS VER. 21.0 was used. Results - Variables having influence upon bankruptcy forecast models included total asset increase ratio and operating income increase ratio of growth index and sales to account receivable ratio, and tangible equity ratio and liquidity ratio of liquidity ratio. The study selected total asset operating ratio, and earning and expenditure ratio from profitability index, and receivable turnover ratio of activity index. Conclusions - Financial supervising system should be improved and financial consumers should be protected to develop saving bank and to control risk, and information on financial companies should be strengthened.