• Title/Summary/Keyword: appearance property

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Distribution of Alexandrium tamarense in Drake Passage and the Threat of Harmful Algal Blooms in the Antarctic Ocean

  • Ho, King-Chung;Kang, Sung-Ho,;Lam Ironside H.Y.;Ho, dgkiss I.John
    • Ocean and Polar Research
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    • v.25 no.4
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    • pp.625-631
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    • 2003
  • While phytoplankton diversity and productivity in the Southern Ocean has been widely studied in recent years, most attention has been given to elucidating environmental factors that affect the dynamics of micro-plankton (mainly diatoms) and nano-plankton (mainly Phaeocystis antarctica). Only limited effects have been given to studying the occurrence and the potential risks associated with the blooming of dinoflagellates in the relevant waters. This study focused on the appearance and toxicological characteristics of a toxic dinoflagellate, Alexandrium tamarense, identified and isolated from the Drake Passage in a research cruise from November to December 2001 The appearance of A. tamarense in the Southern Ocean indicates the risk of a paralytic shellfish poisoning (PSP) outbreak there and is therefore of scientific concern. Results showed that while the overall quantity of A. tamarense in water samples from 30meters below the sea surface often comprised less than 0.1% of the total population of phytoplankton, the highest concentration of A. tamarense (20 cells $L^{-1}$) was recorded in the portion of the Southern Ocean between the southern end of South America and the Falkland Islands. Waters near the Polar Front contained the second highest concentrations of 10-15 cells $L^{-1}$. A. tamarense was however rarely found in waters near the southern side of the Polar Front, indicating that cold sea temperatures near the Antarctic ice does not favor the growth of this dinoflagellate. One strain of A. tamarense from this cruise was isolated and cultured for further study in the laboratory. Experiments showed that this strain of A. tamarense has a high tolerance to temperature variations and could survive at temperatures ranging from $5-26^{\circ}C$. This shows the cosmopolitan nature off. tamarense. With regard to the algal toxins produced, this strain of A. tamarense produced mainly C-2 toxins but very little saxitoxin and gonyailtoxin. The toxicological property of this A. tamarense strain coincided with a massive death of penguins in the Falkland Islands in December 2002 to January 2003.

A Study on the Optical Properties of the Filament Yarn Weft Knit Fabrics and the 3-dimensional Model (필라멘트로 구성(構成)된 위편성물(緯編成物)및 모델의 광학적(光學的) 특성(特性)에 관(關)한 연구(硏究))

  • Shin, Hye-Sun;Kim, Jong-Jun;Jeon, Dong-Won
    • Journal of Fashion Business
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    • v.6 no.5
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    • pp.1-11
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    • 2002
  • Today, great percentage of apparel fabrics comprise knit products. A few apparel items are almost exclusively made from knit products including sweaters, T-shirts, lingerie, and hosiery. In weft knits, intermeshing yarn traverses the fabric crosswise. The production rate of knitting machines is about four times higher than that of conventional looms iin proportion to the amount of fabric produced per unit time. Knit apparels fabrics are noted for freedom of body movement, easy-care, resilience, soft draping and quality. The appearance of fabrics is of prime importance along with tactile features such as smoothness, crispness, stiffness when we deal with the handling evaluation of the textiles. In practice, the quality and performance of fabrics judged by sighted evaluators, and it is perhaps logical, in attempting to establish an effective fabric objective measurement system. It is worthwhile to make objective measurement that correlate well with subjective evaluations made by sight and touch together. However, it often imposes difficulties to effectively measure and analyze the appearance or optical properties of the textile surface features. In this study, an attempt is made to provide a preliminary approach to the analysis of the gloss property, which is one of the optical properties of fabrics. The specimens range from 70/24 nylon 6 filament yarn knit fabric to 70/68 nylon 6 filament yarn knit fabric, the latter being finer. A few three-dimensional models based on Peirce's model of knit stitch have been proposed and material properties were given to calculate the properties. Goniophotometric measurements of the specimens were also carried out.

Flow Visualization by Light Emission in the Post-chamber of Hybrid Rocket (광도측정에 의한 하이브리드 로켓 후연소실의 유동 가시화)

  • Park, Kyung-su;Choi, Go Eun;Lee, Changjin
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.43 no.8
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    • pp.677-683
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    • 2015
  • Hybrid rocket combustion displays low frequency instability(LFI, 10~30Hz) at a certain condition. Vortex shedding in the post-chamber is suspected to cause the occurrence of LFI. This study focused on the visualization of flow image using light emissions from high temperature combustion gas. Results shows that combustion pressure oscillates at a frequency of about 18 Hz, which is in phase with oscillations of light emission. Since LFI is not a property of thermo-acoustic instability, this result suggested there exists a physical coupling of pressure fluctuations with light emissions proportional to chemical reaction. Also POD analysis shows that dominant symmetric spatial modes in the stable combustion shift suddenly into asymmetric spatial pattern with the appearance of LFI. Especially, the appearance of mode 3 is a typical change of flow dynamics in unstable combustion representing a rotational fluid motions associated with vortex shedding.

Physicochemical Properties of Puffed Snack Using Pellet Added with Ginseng Powder (인삼분말을 첨가한 Pellet과 이를 이용하여 제조한 팽화과자의 특성)

  • Park, Dong Hyeon;Jeong, Hayeong;Choi, Mi-Jung;Cho, Youngjae
    • Food Engineering Progress
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    • v.23 no.3
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    • pp.186-192
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    • 2019
  • This study was conducted to improve functionality and nutrition for the utilization of ginseng. Ginseng powder pellets containing various moisture contents (1%, 4%, 7% or 10%) were prepared and mixed with rice as 1:1 (w/w). Then, samples were puffed at 180, 190, 200, 210 or 220℃. The puffed ginseng snacks were analyzed for appearance, color, hardness, specific volume and principal component analysis. For appearance analysis, when snack samples containing ginseng pellets with moisture content of 7% or higher were puffed at 200℃, they showed unbroken round shape. For color analysis, the values of L* and a* tended to increase as the moisture content of pellet and puffing temperature increased. As the water content of pellet and the pumping temperature increased, the specific volume of the puffed ginseng snack increased, while the hardness of the sample decreased. In conclusion, all results supposed that the processing conditions including moisture of pellet and puffing temperature had influenced on the physicochemical properties of puffed ginseng snack.

Study on Rheological and Sensory Properties of Cooked Rices -I. Changes in Flavor and Appearance of Cooked Rices during Storge- (쌀 품종에 따른 쌀밥의 물리적 및 관능적 특성 연구 -I. 저장중 쌀밥의 풍미 및 겉모양의 변화-)

  • Kim, Chong-Kun;Hwang, Jeen-Sun;Kim, Woo-Jung
    • Applied Biological Chemistry
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    • v.30 no.2
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    • pp.109-117
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    • 1987
  • Three rice varieties of Akibare (japonica), Milyang 30 (indica) and Taebaeg (indica) were investiated for sensory and physical qualities of cooked rices during storage at the temperature range of $4^{\circ}C$ and $70^{\circ}C$ for 25 hours. The qualities studied were sensory attributes of odor, taste and appearance which were evaluated by multiple comparison method. The other properties were size of rice granule and separation Property of individual cooked rices in water. The sensory results showed that all of the descriptions except moldy odor and oily taste were scored higher values for cooked rices of Akibare than those values of Milyang 30 and Taebaeg. It was found that storage of cooked rices at various temperatures resulted a significant decrease in most of sensory qualities except moldy odor and oily taste which were rather increased. The quality change was more affected at storage at low temperature, particularly at $4^{\circ}C$, than at higher temperatures. The property of individual separation of cooked rices in water for freshly cooked rices showed that Akibare was separated 44.4% after 1 minute shaking while Milyang 30 and Taebaeg had the higher separation value of 53.1%, and 51.0%, respectively. This characteristic was noticeably reduced after 3 hours storage and then steady increased during further storage. It was also found that the separation percent was generality increased as the storage temperature increased from $4^{\circ}$ to $70^{\circ}C$.

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Property of Uljin-Geumgangsong Wood (Pinus densiflora forma erecta Uyeki): Appearance Pattern of Resin Canal and Ray (울진 금강송재의 재질: 수지구 및 방사조직의 출현형태)

  • Kim, Dong-Woo;Hwang, Sung-Wook;Lee, Won-Hee
    • Journal of the Korean Wood Science and Technology
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    • v.42 no.1
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    • pp.78-87
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    • 2014
  • It was examined the key criterion of the time of property revelation as Uljin-Geumgangsong wood. For this purpose, we investigated in physical properties in pine wood (Pinus densiflora Sieb. et Zucc.) and representative Uljin-Geumgangsong wood (Pinus densiflora forma erecta Uyeki). The results are as follows; Air-dry density of Uljin-Geumgangsong wood have higher values over about 20 percent than that of pine wood. And also heartwood rate of Uljin-Geumgansong wood have higher values above 70 percent. The number of vertical resin canals per $1mm^2$ in Uljin-Geumgangsong wood was 40 percent greater than in pine wood. As the average diameters of axial resin canals were 67.8 mm and 67.3~69.9 mm in pine wood and in Uljin-Geumgangsong wood, respectively, there was no significant difference among wood species. There tends to be an increase in diameters as annual rings increase. The number of horizontal resin canals in Uljin-Geumgangsong-1 was approximately 55 percent greater than in pine wood and Uljin-Geumgangsong-2. The number of resin canals in pine wood and Uljin-Geumgangson-2 decreased while it increased in Uljin-Geumgangsong-1 as annual rings increased. No significant difference was found in the number of rays among wood species and between earlywood and latewood of same wood species. As annual rings increased the number of rays decreased in both pine wood and Uljin-Geumgangsong. The heights of rays were greater in pine wood than Uljin-Geumgangsong and no difference was found between earlywood and latewood. In conclusion, rings of tree for the time of property revelation as Uljin-Geumgangsong wood is assumed about more than 150 years.

Ellipsometric study of Mn-doped $Bi_4Ti_3O_{12}$ thin films

  • Yoon, Jae-Jin;Ghong, Tae-Ho;Jung, Yong-Woo;Kim, Young-Dong;Seong, Tae-Geun;Kang, Lee-Seung;Nahm, Sahn
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.08a
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    • pp.173-173
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    • 2010
  • $Bi_4Ti_3O_{12}$ ($B_4T_3$) is a unique ferroelectric material that has a relatively high dielectric constant, high Curie temperature, high breakdown strength, and large spontaneous polarization. As a result this material has been widely studied for many applications, including nonvolatile ferroelectric random memories, microelectronic mechanical systems, and nonlinear-optical devices. Several reports have appeared on the use of Mn dopants to improve the electrical properties of $B_4T_3$ thin films. Mn ions have frequently been used for this purpose in thin films and multilayer capacitors in situations where intrinsic oxygen vacancies are the major defects. However, no systematic study of the optical properties of $B_4T_3$ films has appeared to date. Here, we report optical data for these films, determined by spectroscopic ellipsometry (SE). We also report the effects of thermal annealing and Mn doping on the optical properties. The SE data were analyzed using a multilayer model that is consistent with the original sample structure, specifically surface roughness/$B_4T_3$ film/Pt/Ti/$SiO_2$/c-Si). The data are well described by the Tauc-Lorentz dispersion function, which can therefore be used to model the optical properties of these materials. Parameters for reconstructing the dielectric functions of these films are also reported. The SE data show that thermal annealing crystallizes $B_4T_3$ films, as confirmed by the appearance of $B_4T_3$ peaks in X-ray diffraction patterns. The bandgap of $B_4T_3$ red-shifts with increasing Mn concentration. We interpret this as evidence of the existence deep levels generated by the Mn transition-metal d states. These results will be useful in a number of contexts, including more detailed studies of the optical properties of these materials for engineering high-speed devices.

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A comparative study of Curcuma longa L. and Curcuma aromatica S. in medical texts (강황(薑黃)과 울김(鬱金)의 역대문헌(歷代文獻)에 대(對)한 비교(比較) 연구(硏究))

  • Kim, Yong-Ryul;Lee, Hyun-Jeong;Jeong, Hyun-Jong;Keum, Kyung-Soo
    • Journal of the Korean Institute of Oriental Medical Informatics
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    • v.17 no.1
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    • pp.203-255
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    • 2011
  • This study covers the historical aspects of the turmeric and curcuma only in detail on the medicinal uses, supported by references to the medical texts. And the result is as follows: 1. Turmeric and curcuma are rhizomatous herbaceous perennial plants of the ginger family, but both produced on the same herb. The rhizome is considered turmeric while the tuber is considered curcuma. 2. Turmeric is the round, oval, or ovate, and scutiform rhizome. 3. Curcuma is yellowish externally, internally more or less orange-yellow passing into reddish-brown. The tuber has a round and cuspidate appearance. The smell is aromatic, somewhat analogous to ginger. 4. Turmeric is somewhat analogous to curcuma in shape, but turmeric is pungent and bitter in taste, warm and intoxious in property, and yellow in color, acting on the spleen and liver channels and governing the gi of the blood while curcuma is pungent and bitter in taste, cold and intoxious in property, red in color, acting on the heart and pericardium channels and governing the blood. 5. Turmeric is referred to zedoary, sliced turmeric, old jaundice, precious aromatic, and ovate rhizoma, and curcuma is referred to radix curcuma, curcuma aromatica, and cicada-belly curcuma

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Level of Length Detail for Representing Virtual Objects' Real Length (가상 객체의 실제 길이 표현을 위한 다중 레벨)

  • Lee, Myeong-Won;Im, Chang-Hyuck;Lee, Yong-Duck
    • Journal of the Korea Computer Graphics Society
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    • v.13 no.3
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    • pp.25-31
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    • 2007
  • Current computer graphics technology creates and displays virtual objects in a normalized environment. We cannot know or assume the real physical properties of objects related to appearance without textual information. It is also difficult to represent any two objects in relation to each other when the difference between the two objects' size is large because of the limited resolution of the computer display. In order to solve the problem, we define and implement the real length property among the physical properties in virtual environments. We define the concept of LOLD (Level of Length Detail) to represent real-world length for objects in metric units such as millimeter, meter, kilometer, etc.

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Effects of Physicochemical and Gel Properties of Starches Purified from Korean and Chinese Mungbeans with Different Methods (한국산과 중국산 녹두로부터 방법을 달리하여 분리한 전분의 이화학적 및 겔 특성에 미치는 영향)

  • Qian, Yurun;Shin, Malshick
    • Korean journal of food and cookery science
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    • v.28 no.6
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    • pp.871-881
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    • 2012
  • To compare the physicochemical and gel properties of mung bean starches prepared by different purification methods, starches from Korean Eohul variety and Chinese mung bean (MB) with or without hull using alkaline solution or water as solvent were purified. The optimum conditions for making muk were investigated. Apparent amylose and total dietary fiber contents, water binding capacity, solubility and pasting properties by RVA were analyzed. The characteristics of starch gels (10% dry basis) were measured for 0 and 4 day stored at $4^{\circ}C$. The protein and ash contents were significantly different (p<0.05) and lowered in starch from dehulled MB using alkaline solution. The starches from dehulled MB using alkaline solution showed the lowest color differences. Apparent amylose contents of Eohul and Chinese starches showed 37.06-39.03% and 31.57-32.74%, respectively. Chinese starch was higher in water binding capacity but lower in solubility at $85^{\circ}C$ than others. Peak, trough, cold, and breakdown viscosities of Eohul starch were higher than those of Chinese one. Mung bean starch gel made immediately exhibited clear and glossy appearance but became whiter like milk. The crystallinities of starch and starch gel showed A and B types, respectively. The hardness, gumminess, and resilience of starch gel made immediately and hardness, cohesiveness, gumminess, and resilience of 4 day stored gels were different significantly (p<0.05). Especially, Eohul starch gels purified from hulled MB showed higher resilience (bending property) and hardness. Therefore, it was suggested that high quality muk would be made using MB starch purified from hulled Korean mung bean using water as solvent.decreased in contain more than 20% of SGP added groups. The optimal concentration of SGP was found in the range of less than 10%.