• Title/Summary/Keyword: Mass changes

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Effect of Refrigerated and Thermal Storage on the Volatile Profile of Commercial Aseptic Korean Soymilk

  • Kim, Hun;Cadwallader, Keith R.;Jeong, Eun-Jeong;Cha, Yong-Jun
    • Preventive Nutrition and Food Science
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    • v.14 no.1
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    • pp.76-85
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    • 2009
  • This study determined the effect of refrigerated and thermal storage on the volatile profile of commercial aseptic soymilk. Volatile components in commercial aseptic soymilk stored either under refrigerated ($4^{\circ}C$) or thermal ($55^{\circ}C$) conditions for 30 days were periodically analyzed by combined solvent-assisted flavor evaporation-gas chromatography-mass spectrometry (SAFE-GC-MS). The concentrations of most of the volatile components, including aldehydes, ketones, alcohols, acids, nitrogen- and sulfur-containing compounds, alkylfurans, furan derivatives and phenolic compounds, were affected to a greater extent by thermal storage compared with refrigerated storage. Profound increases in some volatile compounds with low odor detection thresholds, such as hexanal, octanal, (E)-2-octenal, (E,E)-2,4-decadienal, 1-octen-3-ol, 3-ethyl-2,5-dimethylpyrazine, 2,3-diethyl-5-methylpyrazine, 2-pentylfuran, 4-hydroxy-2,5-dimethyl-3(2H)-furanone, dimethyl trisulfide, guaiacol, 4-vinylguaiacol and 4-vinylphenol, were observed in thermal stored soymilk. The volatile profile changes caused by thermal storage may influence the aroma quality of thermal-stored aseptic soymilk.

A Comparative Study of Corsetry Methods (Corsetry 제작법 비교연구)

  • Park, Sang-Hee
    • Journal of the Korean Society of Costume
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    • v.58 no.4
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    • pp.99-112
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    • 2008
  • The aim of the study was to look into the construction methods of historical corsetry and compare them with the construction methods of corsetry today. Through a comparative study, it was concluded that the design, material, sewing and functions of corsetry of a certain period are sum of the clothing techniques and fashion of the time. Corset was first appeared at the end of the 16th century. It has been through many changes in terms of items, materials, patterns, sewing methods in order to make right silhouettes of the time. Now corsetry has been developed into various items such as waist nipper, all-in-one, nipper bra, and girdle. All these items have a common purpose, that is to improve the body shape. The corsetry of the past was made of non stretchable materials, so they used to restrict body movements, and required individual fitting several times. Due to the development of thin durable stretchable fabrics, functional bones, and advanced sewing machines, construction methods of seam, hem and opening are simplified compare to their predecessors. Consequently corsetry became less weighted, easy to wear, easy to wash and easy to mass produce. Yet they have consistency in sewing techniques such as using bones or wires to support bodice shape, using durable twill fabrics over plain for attractive body shapes.

A Study on the Optimal Sizing System for Obese Children - Focusing on 4~6 Grade Elementary School Boys- (비만 남아를 위한 최적 규격치 설정 및 사이즈 스펙 개발 - 초등학생 4~6학년을 중심으로 -)

  • Choi, Kueng-Mi;Park, Sun-Mi;Kim, Woong;Ryu, Young-Sil
    • Fashion & Textile Research Journal
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    • v.11 no.6
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    • pp.918-924
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    • 2009
  • As the population of overweight and obese children is rising rapidly around the world, there are many researches on purchasing and wearing children's clothing and optimal sizes, but researches on obese children are still inadequate. This study was carried out on 192 obese children over 75% in BMI. The purpose of the study was to set up the optimal interval of sizing system using the loss function which would be a guide for obese children for selecting ready to wear of suitable size. Introducing a loss function, which reflects how much the purchasing desire changes according to the difference, we formulate the problem and suggest a procedure to determine the optimal standard sizes minimizing the loss. These results were as follows ; In size chart of top's, 4 sizes had been determined by a loss function, had covered more than 91.1% of all subjects. In size chart of bottom's, 5 sizes had been determined by a loss function, had covered more than 87.0% of all subjects.

suspension dynamics of HDD for high track density (고트랙밀도 HDD 서스펜션의 동특성 해석)

  • Kim, Chung-Joo;Chun, Jeong-Il;Byun, Yong-Kyu;Ro, Kwang-Choon;Chung, Chung-Choo;Jeong, Tae-Gun
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.21 no.11
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    • pp.1885-1895
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    • 1997
  • As track density needs to increase to the order of 10, 000 tpi, the suspension has become a critical component in hard disk drives. One of the main obstacles to attain high track density is the structural resonances of the suspension in lateral direction. We investigate the suspension dynamics through the experimental modal analysis and the finite element method. An LDV (Laser Doppler Vibrometer) is employed to measure the response of the suspension which is excited by a shaker and an inpulse hammer for the free condition and the loaded condition, respectively. After comparing the experimental and numerical results, we study how the initial geometry of the bend region affects the suspension dynamics. It is found that the natural frequency of the sway mode decreases as the bend ratio and the bend angle increase. The shape of torsional mode changes as the mass of a slider increases, resulting in a local decrease in the natural frequency.

Experimental study on hot-wire type air flow rate measurement system considering ambient temperature compensations (온도보상을 고려한 열선형 공기유량 측정시스템에 관한 실험적 연구)

  • 이민형;유정열;김사랑;고상근;윤준원;김동성
    • Journal of the korean Society of Automotive Engineers
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    • v.13 no.4
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    • pp.62-75
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    • 1991
  • The purpose of this study is to perform modelings and experiments to measure air flow rate using hot-wires and a CTA(Constant Temperature Anemometer). The flow rate can be obtained by measuring the heat loss of the hot-wire due to the variations of flow velocity when the hot-wire is maintained at uniform temperature. But the defect of this method is that the output signal changes not only by the flow rate but also by the ambient temperature. Thus, in the present study, a method which compensates the variations of the ambient temperature has been introduced to measure exact flow rate. To be more specific, the bridge circuit of the usual hot-wire anemometer system has been modified in such a way that a temperature resistance sensor and a variable resistance are placed in one of the legs to compensate the different temperature coefficients of both the hot-wire and the temperature compensating resistance for flow velocity or for flow mass up to the flow temperature of 50 .deg.C. Comparing the modeling and experimental results, it has been shown that the compensating point differs as the flow rate varies. Therefore, optimum compensation points are sought to construct the circuit. The present modeling and experimental results may be applied to the design of actual air flow meters for automobiles.

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Methylation Changes at the First Exon of Bovine oct-4 Gene in Embryos Produced Either by In Vitro Fertilization or Somatic Cell Nuclear Transfer

  • Seungeun Yeo;Park, Jung-Sun;Wee, Kap-In;Lee, Hyo-Sang;Koo, Deog-Bon;Lee, Kyung-Kwang;Han, Yong-Mahn;Kang, Yong-Kook
    • Proceedings of the KSAR Conference
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    • 2002.06a
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    • pp.62-62
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    • 2002
  • The relationship of Oct-4 to pluripotent cells is suggested by its tightly restricted expression pattern during embryonic development. Just prior to implantation it is limited to pluripotent cells of the inner cell mass (ICM) that will form the embryo proper but is not expressed in the trophectoderm, the structure that will form the extraembryonic tissues. (omitted)

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A study on gas vent control of injection mold for the production of precision medical device parts (정밀 의료기기 부품 생산을 위한 사출금형의 가스벤트 제어에 관한 연구)

  • Lee, Jeong-Won;Son, Min-Kyu
    • Design & Manufacturing
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    • v.14 no.2
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    • pp.34-41
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    • 2020
  • Typical characteristics of medical device parts are that they can not be reused and there are many disposable products. Therefore, there is a need for an injection molding machine having excellent repeatability of molding conditions and a precision injection mold for mass production. Recently, the performance of an injection machine has made a remarkable evolution compared to the past. However, defects such as short-shot, flash, weld line, gas burning, warpage, and deformation, which are typical defects, still do not disappear at all. This is due to the lack of gas ventilation from the product cavities, even if the gas is smoothly vented from the sprue and runner of the mold. For this reason, the internal pressure of the cavity rises and is directly connected to the quality defects. In this study, an active gas vent system was designed to prevent defects due to trapped gas in the cavity. Since it can be easily adjustable in response to the molding conditions and the mold temperature changes, it is expected to improve productivity due to the reduction of the defective ratio.

A study on the ecosystem-based management system for fisheries resources in Korea (생태계 차원에서의 수산자원관리 방안 연구)

  • Zhang, Chang-Ik
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.42 no.4
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    • pp.240-258
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    • 2006
  • The potential of ecosystem-based fisheries management is recently recognized to be very important to improve the sustainability of fisheries resources. Under the depressed condition of many fisheries resources, this recognition has been expanded and more effort has been taken to improve this approach. Taking ecosystem concept includes the use of other tools of management in addition to fisheries regulation, such as stock and productivity enhancement, provision of physical structure, or marine protected areas. In the ecosystem-based fisheries management approach, it would require to holistically consider ecological interactions of target species with predators, competitors, and prey species, the effects of climate on fisheries ecology, the complex interactions between fishes and their habitat, and the effects of fishing on fish stocks and their ecosystem. Fisheries management based upon the understanding of these factors can prevent significant and potentially irreversible changes in marine ecosystems caused by fishing. A useful approach for analyzing tropho-dynamic interactions and mass-balance in marine ecosystems is introduced to demonstrate the complexity and usefulness of the ecosystem approach, which was applied to a small ecosystem in Korea. Korea should seriously consider to take the ecosystem-based approach to fisheries management, since most major fish stocks are currently depleted due to many reasons such as overfishing, land reclamation and coastal pollution.

Deregulation of Aspartokinase by Single Nucleotide Exchange Leads to Global Flux Rearrangement in the Central Metabolism of Corynebacterium glutamicum

  • Kim Hyung-Min;Heinzle Elmar;Wittmann Christoph
    • Journal of Microbiology and Biotechnology
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    • v.16 no.8
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    • pp.1174-1179
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    • 2006
  • The wild-type Corynebacterium glutamicum ATIC 13032 and Corynebacterium glutamicum ATTC 13032 lysC S301Y, exhibiting a deregulated aspartokinase, were compared concerning growth, lysine production, and intracellular carbon fluxes. Both strains differ by only one single nucleotide over the whole genome. In comparison to the wild-type, the mutant showed significant production of lysine with a molar yield of 0.087 mol (mol glucose$^{-1}$) whereas the biomass yield was reduced. The deregulation of aspartokinase further led to a global rearrangement of carbon flux throughout the whole central metabolism. This involved an increased flux through the pentose phosphate pathway (PPP) and an increased flux through anaplerosis. Because of this, the mutant revealed an enhanced supply of NADPH and oxaloacetate required for lysine biosynthesis. Additionally, the lumped flux through phosphoenolpyruvate carboxykinase and malic enzyme, withdrawing oxaloacetate back to the glycolysis and therefore detrimental for lysine production, was increased. The reason for this might be a contribution of malic enzyme to NADPH supply in the mutant in the mutant. The observed complex changes are remarkable, because they are due to the minimum genetic modification possible, the exchange of only one single nucleotide.

The Effects of Dietary Ca Levels on Ca and Skeletal Metabolism in Ovariectomized Rats of Different Age (난소를 절제한 나이가 다른 흰쥐에서 식이 칼슘 수준이 골격 대사에 미치는 영향)

  • 김화영
    • Journal of Nutrition and Health
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    • v.31 no.4
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    • pp.716-728
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    • 1998
  • To investigate the effect of dietary Ca levels on metabolic changes of Ca and skeleton in postmenopausal women, 10-month-old ovariectomized female rats were compared with 2 month old rats. The rats were fed either 0.2% or 1.2% Ca diets for 16 weeks. Food intake and weight gain as higher in rats fed high Ca diets and in ovariectomized rats. Apparent Ca absorption as higher, and Ca balance was lower in the low Ca groups. Vertebrae density was higher in old rats or those fed a high Ca diets. The old rats and ovariectomized rats showed decreased bone formation, increased bone resorption and kidney function deterioration resulting in increased urinary Ca excretion. Contradictory to the above observation, old rats and ovariectomized rats still showed higher bone mass and bone ash content. Therefore aging was not fully onging in 10-month-old rats. Bone weights, mineral contents, and mineral/wt ratio were lower in ovariectomized rats. Dietary Ca level did not affect urinary Ca excretion, urinary protein excretion, GFR, serum alkaline phosphatase, or urinary hydroxyporline excretion. This means that dietary Ca level did not influence kidney function or bone turnover. However Ca content and the ash content of femur, 4th vertebra, and scapula were increased in high Ca groups. Therefore, it is considered that decreased bone formation and accelerated bone resorption may account for the increased osteoporotic risk in women in menopause after middle age. However, Ca metabolism can be improved and bone components can be maintained if Ca is supplemented.

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