• Title/Summary/Keyword: Height loss

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Effect of Heating Height within Microwave Oven on Microwave Heating of Food (전자레인지 내부에서 가열높이 변화가 품질 특성에 미치는 영향)

  • Kum, Jun-Seok;Ha, Tae-Youl;Han, Ouk
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.27 no.3
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    • pp.489-494
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    • 1998
  • For the purpose of improving the qualities of popcorn, potato, frozen hotdog and steamed egg, the effects of food height(0mm: HO, 5mm: H5, 10mm, 15mm: H15) for microwave cooking on physicochemical properties were investigated. In popcorn, weight loss was decreased as height increased while volume of popcorn was increased, which indicated that popcorn was poped very well as height increased. H10 showed the highest taste score in sensory evaluation. In potato, degree of gelatinization was increased as hight increased. H10 showed the highest overall acceptance score. In frozen hotdog, hardness of hotdog was decreased as hight increased and H15 showed the lowest hardness score (408.8g). In steamed egg, H5 showed the highest temperature and H10 showed the highest overall acceptance score. Physicochemical properties of food were changed by heating height of microwave heating.

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Body Height Effect on Brain Volumes in Youth Decreases in Old Age in Koreans

  • Koh, In-Song
    • Interdisciplinary Bio Central
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    • v.3 no.3
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    • pp.11.1-11.5
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    • 2011
  • The MRI (magnetic resonance imaging) volumetric analysis of the brain was performed in 59 healthy elderly Koreans (aged 62-76 years; 34 male, 25 female) to investigate whether the previously reported significant correlations between body height and brain volumes in the young aged Koreans (20's) still exist in the old aged Koreans (60's and 70's). Unlike previously reported significant correlations in the young aged Koreans, neither the correlation between whole brain volume and body height in male nor the correlation between cerebellar volume and body height in female show any significance in the old aged Koreans. The significant correlation between body height and whole brain volume was still observed when both male and female data were combined (r=0.27, P<0.05), but the correlation coef-ficient and the level of significance markedly decreased from those of previously reported Korean youth data (r=0.67, P<0.01). Simple linear regression analysis shows decrease of explanatory power of height (measured in $r^2$) from 44% in the youth group to 7% in the old age group on the variance of whole brain volume. Multiple linear regression analysis shows that age and sex, rather than height, are major explanatory variables for whole brain volume in the old aged Koreans. The loss of correlations in the aged group is suspected to be mainly due to age related brain volume changes.

A Computational Study on the Pressure Loss of Intake System for the Combat Vehicle (전투차량 흡기시스템의 압력손실에 관한 수치적 연구)

  • Moon, Seong-Mok;An, Su-Hong;Lee, Kyoung-Hoon;Woo, Kwan-Je
    • The KSFM Journal of Fluid Machinery
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    • v.15 no.3
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    • pp.25-31
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    • 2012
  • A computational study on the improvement of the pressure loss of intake system, which is located at engine manifold of the combat vehicle, has been conducted using a finite-volume-based, Reynolds-Averaged Navier-Stokes (RANS) solver. The computational result of the pressure loss through the air cleaner is in good agreement with equivalent experimental data. A parametric study was done for improving of the pressure loss of intake system over the baseline case. The effects of five primary parameters such as the height of inlet, the width of interconnection pipe, the shape of drain chamber and the diameter of filter housing were considered in this study. Consequently, this computational investigation can contribute to finding an optimal guideline for the idea of improvement in the pressure loss of intake system.

Effects of Discrete Rib-Turbulators on Heat/Mass Transfer Augmentation in a Rectangular Duct (사각 덕트 내부 열전달 향상을 위한 요철의 단락 효과)

  • Kwon, Hyuk-Jin;Wu, Seong-Je;Cho, Hyung-Hee
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.24 no.5
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    • pp.744-752
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    • 2000
  • The influence of arrangement and length of discrete ribs on heat/mass transfer and friction loss is investigated. Mass transfer experiments are conducted to obtain the detailed local heat/mass transfer information on the ribbed wall. The aspect ratio (width/height) of the duct is 2.04 and the rib height is one tenth of the duct height, such that the ratio of the rib height to hydraulic diameter is 0.0743. The ratio of rib-to-rib distance to rib height is 10. The discrete ribs were made by dividing each continuous rib into 2, 3 or 5 pieces and attached periodically to the top and the bottom walls of the duct with a parallel orientation The combined effects of rib angle and length of the discrete ribs on heat/mass transfer ae considered for the rib angles $({\alpha})\;of\;90^{\circ}\;and\;45^{\circ}$. As the number of the discrete ribs increases, the uniformity of the heat/mass transfer distributions increases. For $(\alpha})=90^{\circ}$, the heat/mass transfer enhancement with the discrete ribs is remarkable, while the heat/mass transfer performances are slightly higher than that of the transverse continuous ribs due to the accompanied high friction loss penalty. For $(\alpha})=90^{\circ}$, the average heat/mass transfer coefficients and the heat/mass transfer performances decrease slightly with the discrete ribs compared to the case of the angled continuous ribs.

CRANIOFACIAL GROWTH CHANGES FROM SEVEN TO ELEVEN YEAR OLD CHILDREN (두개안면골(頭蓋顔面骨)의 성장변화(成長變化)에 관(關)한 연구(硏究))

  • Lee, Ki Soo
    • The korean journal of orthodontics
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    • v.8 no.1
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    • pp.39-48
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    • 1978
  • The growth changes in craniofacial depth and height from seven to eleven years of age have been studied in thirty two Korean children, consisted of seventeen boys and fifteen girls. The data was obtained from lateral cephalometric radiographs analyzed by the Coben's coordinate system, and the main conclusions might be summarized as follows. 1. Among the craniofacial depth increments the lower facial depth dimension increased the most, mid-facial depth dimension increased loss, and cranial depth dimension increased the least. 2. In spite of the increasing depth dimensions, the mid-facial depth proportion had a tendency to remain stable. 3. The degree of overbite increased markedly from seven to eleven years of age. 4. Increment in the total anterior facial height dimension was larger than that in the total posterior facial height, and the upper anterior facial height increased more than the lower anterior facial height. 5. The lower facial depth proportion increased markedly, and the convexity of the face was reduced significantly. 6. The posterior facial height tended to show small proportional changes. 7. The growth increments in craniofacial complex were larger in the facial height than in the facial depth.

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A Data Gathering Approach for Wireless Sensor Network with Quadrotor-based Mobile Sink Node

  • Chen, Jianxin;Chen, Yuanyuan;Zhou, Liang;Du, Yuelin
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.6 no.10
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    • pp.2529-2547
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    • 2012
  • In this paper, we use a quadrotor-based mobile sink to gather sensor data from the terrestrial deployed wireless sensor network. By analyzing the flight features of the mobile sink node, we theoretically study the flight constraints of height, velocity, and trajectory of the mobile sink node so as to communicate with the terrestrial wireless sensor network. Moreover, we analyze the data amount which the mobile sink can send when it satisfies these flight constraints. Based on these analysis results, we propose a data acquisition approach for the mobile sink node, which is discussed detailed in terms of network performance such as the transmission delay, packet loss rate, sojourning time and mobile trajectory when given the flying speed and height of the mobile sink node. Extensive simulation results validate the efficiency of the proposed scheme.

Combustion characteristics in small combustion chamber that has high surface to volume ratio (고 표면적-체적 비를 가지는 소형 연소실 환경에서의 연소특성)

  • Lee, Dae-Hoon;Choi, Kwon-Hyoung;Kwon, Se-Jin
    • 한국연소학회:학술대회논문집
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    • 2000.12a
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    • pp.212-216
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    • 2000
  • Combustion phenomenon in scale-downed combustor is investigated. As the combustor volume decreases surface to volume ratio increases. for increased surface to volume ratio means increased heat loss and this increased heat loss affects reaction in combustion chamber. Plastic mini combustor is made. Stoichiometricaly premixed Hydrogen I air gas is used as fuel. Initial chamber pressure and chamber size are varied and the effects are evaluated. Peak pressure decreases with the decrease in chamber height. As initial chamber pressure decreases peak pressure decreases. And this change is more important than scale down effect till the chamber height of 1mm. With this result and further information following the experiments design parameter for micro engine can be established.

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Combustion Characteristics in Small Combustion Chamber Size about Quenching Distance (소염 거리에 근접하는 소형 연소실 환경에서의 연소특성)

  • Lee, Dae-Hoon;Choi, Kwon-Hyoung;Kwon, Se-Jin
    • Journal of the Korean Society of Combustion
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    • v.5 no.2
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    • pp.63-68
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    • 2000
  • Combustion phenomenon in scale-downed combustor is investigated. As the combustor scale decreases surface to volume ratio increases and chamber size approaches quenching distance. As the combustor scales down surface to volume ratio increases resulting increased heat loss. And this heat loss can affect quenching and instability of the flame. To investigate this effect plastic mini combustor is made. Stoichiometricaly premixed Hydrogen / air gas is used as fuel. Initial chamber pressure and chamber size are varied and the effects are evaluated. Peak pressure decreased with the decrease in chamber height. As initial chamber pressure decreases peak pressure decreases and this change is more important than scale down effect till the chamber height of 1mm. With this result and further information following the experiments design parameter for micro engine can be established.

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Analysis of a Modified Plate Fin for Enhanced Performance of a Plate Fin Heat Exchanger (평판 핀 열교환기의 성능 향상을 위한 변형된 평판 핀에 대한 해석)

  • 김윤하;강형석
    • Transactions of the Korean Society of Automotive Engineers
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    • v.9 no.3
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    • pp.84-91
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    • 2001
  • Comparison between performance of a plate fin and that of a modified plate fin is investigated as a function of the position, the non-dimensional width and height of wings as well as the non-dimensional fin length using a two-dimensional separation of variables method. The ratio of the incremental rate of heat loss to that of the area of a modified plate fin is also presented as a function of the height of wings. The modified plate fin is made by attaching the wings to upper and lower sides of a plate fin. One of the results shows that performance of a modified plate fin is more improved as the wings approach left (higher) thermal reservoir.

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Reflection and Dissipation Characteristics of Non-overtopping Quarter Circle Breakwater with Low-mound Rubble Base

  • Balakrishna, K;Hegde, Arkal Vittal;Binumol, S
    • Journal of Advanced Research in Ocean Engineering
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    • v.1 no.1
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    • pp.44-54
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    • 2015
  • Breakwaters are the coastal structures constructed either perpendicular (shore connected) or parallel (detached) to the coast. The main function of breakwater is to create a tranquil medium on its leeside by reflecting the waves and also dissipating the wave energy arriving from seaside, resulting in ease of manoeuvrability to boats or ships to their berthing places. Different types of breakwaters are being used at present, such as rubble mound breakwater, vertical wall type breakwater and composite breakwater. The objective of this paper is to investigate reflection coefficients (Kr) and dissipation (loss) coefficients (Kl) for physical models of Quarter circle caisson breakwater of three different radii of 0.550 m, 0.575 m and 0.600 m with S/D ratio of 2.5 (S=spacing between perforations, D=diameter of perforations). The models were tested in the monochromatic wave flume of the department, for different incident wave heights (Hi), Wave periods (T) and water depths (d). It was observed that reflection coefficient increased with increase in the wave steepness (Hi/gT2) and decreased with increase in depth parameter (d/gT2) and hs/d (Height of structure including rubble base/depth of water). The loss coefficient decreased with increase in the wave steepness and increased with increase in depth parameter and hs/d.