• 제목/요약/키워드: Shell index

검색결과 273건 처리시간 0.034초

굴, Crassostrea gigas 유생의 먹이생물 섭취 크기 (Ingestion size of food microalgae of the Pacific oyster Crassostrea gigas larvae)

  • 허영백;전창영;조기채;허성범
    • 한국패류학회지
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    • 제27권4호
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    • pp.307-315
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    • 2011
  • 유생의 발달크기에 따라 미세조류 12종에 대하여 섭취 가능성을 조사한 결과 유생의 크기에 따라 섭취 가능한 미세조류는 많은 차이를 보였다. 전체 유생크기에서 I. galban, I. aff. galbana, P. lutheri, C. ellipsoidea, N. oculata는 94.2-99.7%의 섭취율를 보였고, C. calcitrans, C. gracilis, C. simplex는 평균 각장 $189.3{\pm}13.8{\mu}m$ 크기인 중형 각 정기 이후 90.0% 이상의 섭취율을 보였다. P. triconutum, D. tertiolecta, T. tetrathele는 평균 각장 $65.0-100.0{\mu}m$의 D형 유생은 섭취가 관찰되지 않았지만, 이후 유생에서는 각각 97.3-99.7%, 43.3-99.3%, 48.5-99.3% 섭취하였다. 그러나 T. weissflogii는 평균 각장 $306.2{\pm}14.7{\mu}m$ 이상에서 1.0-1.7%의 섭취율을 보였지만, 전체 유생기동안 그의 섭취가 되지 않았다. 이상의 결과를 이용해 전체 50.0% 이상 섭취 가능한 먹이생물의 세포크기를 조사한 결과, 평균 각장 $102.3{\mu}m$ 이하의 D형 단계는 장축과 단축 모두 $4.6{\mu}m$ 이하, $158.3{\mu}m$ 미만에서는 장축기준으로 $9.3{\mu}m$ 미만까지 섭취가 가능하고, $158.3{\mu}m$ 이상 크기는 단축 기준 $9.3{\mu}m$까지 섭취가 가능한 것으로 나타났다. 전제 유생기 동안 장축과 단축을 포함해서 $10.0{\mu}m$ 이상은 섭취가 되지 않았다.

The Effects of Dietary Garlic Powder on the Performance, Egg Traits and Blood Serum Cholesterol of Laying Quails

  • Yalcin, Sakine;Onbasilar, Ilyas;Sehu, Adnan;Yalcin, Suzan
    • Asian-Australasian Journal of Animal Sciences
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    • 제20권6호
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    • pp.944-947
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    • 2007
  • This study was conducted to study the effects of dietary garlic powder on laying performance, egg traits and blood serum cholesterol level of quails. A total of three hundred quails (Coturnix coturnix japonica) aged nine weeks were used. They were allocated to 3 dietary treatments. Each treatment comprised 5 replicates of 20 quails. The diets were supplemented with 0, 5 and 10 g/kg garlic powder. The experimental period lasted 21 weeks. The addition of garlic powder did not significantly affect body weight, egg production, feed consumption, feed efficiency, egg shell thickness, egg albumen index, egg yolk index and egg Haugh unit. Adding 5 and 10 g/kg garlic powder to the laying quail diets increased egg weight (p<0.01). Egg yolk cholesterol and blood serum cholesterol concentration were reduced with garlic powder supplementation. The results of this study demonstrated that garlic powder addition had a significant cholesterol-reducing effect in serum and egg yolk without adverse effects on performance and egg traits of laying quails.

Boil-off Loss Ratio of Cocoon Shell as a Selection Criterion in the Newly Developed Bivoltine Silkworm (Bombyx mori L.) Hybrids

  • Seetharamulu, J.;Seshagiri, S.V.;Raju, P.J.
    • International Journal of Industrial Entomology and Biomaterials
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    • 제26권1호
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    • pp.13-21
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    • 2013
  • Boil-off loss ratio is one of the most important economic traits to be considered during the course of silkworm breeding. The boil-off loss ratio varies among the breeds and seasons. The present study was undertaken with 5 oval and 5 peanut breeds and twenty five hybrids involving these parents to select the promising hybrids with desired boil-off loss ratio. Accordingly, studies were undertaken to estimate the heterosis and heterobeltiosis. It was observed that majority of the hybrids revealed negative heterosis for boil-off loss ratio which is desirable. Based on the heterosis and heterobeltiosis, among all the hybrids, the hybrid APBRO5 ${\times}$ APBRD5 exhibited highest negative heterosis for boil-off loss ratio and also exhibited highest EI value (64.5) for the quantitative and qualitative traits. Based on the hybrids performance, boil-off loss ratio, heterosis and heterobeltiosis and evaluation index, the hybrids viz. APBRO5 ${\times}$ APBRD5, APBRO1 ${\times}$ APBRD1 and APBRO3 ${\times}$ APBRD4 were identified for commercial exploitation.

POFA 혼입률에 따른 시멘트 모르타르의 초기 물성에 관한 실험적 연구 (An Experimental Study on the Initial Physical Properties of Cement Mortar with POFA)

  • 위광우;이한승
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2015년도 추계 학술논문 발표대회
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    • pp.122-123
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    • 2015
  • Demands for the replacement materials of cement have been increasing due to social problems such as CO2 reduction and exhaustion of resource. Recently industrial by-products, for example GGBFS and fly ash, have been used as an admixture. However Studies on POFA have been insufficient. POFA, which is used in this study, was obtained from burning of palm oil shell and husk from a southern part of Malaysia. In this study, early compressive strength and porosity of cement mortar with POFA are measured, and appropriate fraction of POFA is 10%. In terms of porosity, POFA is used as a filer in mortar. Later, activity index of POFA and long-term experiments are needed.

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원자로건물 외벽 타설 높이 산정을 위한 수화열 해석 (Analysis on Heat of Hydration for Height of Shell Concrete Pouring in Reactor Containment Building)

  • 김좌영;박종혁;이한우;방창준
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2012년도 추계 학술논문 발표대회
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    • pp.165-166
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    • 2012
  • A thermal stresses by heat of hydration was analyzed according to a change of a pour height in reactor containment building. In case of more than 3.6m pouring height a crack index by heat of hydration analysis resulted in less than 1 because there is not a construction joint of vertical direction and for a self-restraint effect of circumferential section shape. Therefore detailed consideration on a mixture proportion of binder type, quantity in concrete and selection of a form in seasonal air temperature is needed for a control of tensile stress by heat of hydration.

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Thermal buckling analysis of functionally graded sandwich cylindrical shells

  • Daikh, Ahmed Amine
    • Advances in aircraft and spacecraft science
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    • 제7권4호
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    • pp.335-351
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    • 2020
  • Thermal buckling of functionally graded sandwich cylindrical shells is presented in this study. Material properties and thermal expansion coefficient of FGM layers are assumed to vary continuously through the thickness according to a sigmoid function and simple power-law distribution in terms of the volume fractions of the constituents. Equilibrium and stability equations of FGM sandwich cylindrical shells with simply supported boundary conditions are derived according to the Donnell theory. The influences of cylindrical shell geometry and the gradient index on the critical buckling temperature of several kinds of FGM sandwich cylindrical shells are investigated. The thermal loads are assumed to be uniform, linear and nonlinear distribution across the thickness direction. An exact simple form of nonlinear temperature rise through its thickness taking into account the thermal conductivity and the inhomogeneity parameter is presented.

Non-periodic motions and fractals of a circular arch under follower forces with small disturbances

  • Fukuchi, Nobuyoshi;Tanaka, Takashi
    • Steel and Composite Structures
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    • 제6권2호
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    • pp.87-101
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    • 2006
  • The deformation and dynamic behavior mechanism of submerged shell-like lattice structures with membranes are in principle of a non-conservative nature as circulatory system under hydrostatic pressure and disturbance forces of various types, existing in a marine environment. This paper deals with a characteristic analysis on quasi-periodic and chaotic behavior of a circular arch under follower forces with small disturbances. The stability region chart of the disturbed equilibrium in an excitation field was calculated numerically. Then, the periodic and chaotic behaviors of a circular arch were investigated by executing the time histories of motion, power spectrum, phase plane portraits and the Poincare section. According to the results of these studies, the state of a dynamic aspect scenario of a circular arch could be shifted from one of quasi-oscillatory motion to one of chaotic motion. Moreover, the correlation dimension of fractal dynamics was calculated corresponding to stochastic behaviors of a circular arch. This research indicates the possibility of making use of the correlation dimension as a stability index.

POFA를 혼입한 시멘트의 포졸란 반응에 관한 연구 (Study on the Pozzolan Reaction Degree of Palm Oil Fuel Ash as a Mineral Admixture for Sustainable Concrete)

  • 이형민;이한승
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2010년도 춘계 학술대회 제22권1호
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    • pp.335-336
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    • 2010
  • POFA(Palm oil fuel ash)는 Palm fiber 와 shell의 부산물로써 콘크리트용 혼화재로 사용이 가능하다. 그러나 POFA를 사용한 콘크리트의 포졸란 반응에 관한 연구는 매우 적다. 따라서 본 연구에서는 다른 콘크리트용 혼화재료와 동일한 수준으로 POFA의 혼입 치환율을 달리한 모르타르의 압축강도 및 활성도 지수, 포졸란 활성도 지수(API)를 정량적으로 평가하여 혼화재료로서의 적합성을 평가하였다.

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Composition Dependence and Optical Properties of Polymethyl Methacrylate/Alumina Nanocomposite in the IR Region Determined by Kramers-Kronig Relation

  • Ghamari, Misagh;Ghasemifard, Mahdi
    • 한국세라믹학회지
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    • 제54권2호
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    • pp.102-107
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    • 2017
  • The dependence of the IR optical properties of PMMA/$Al_2O_3$ nanocomposite on the alumina content was investigated in the wavelength range of $3500-2800cm^{-1}$. The samples were prepared via emulsion polymerization technique using oleic acid as a coupling agent. Grafting density calculations were carried out by means of elemental analysis CHN to yield the best coupling agent content. FTIR analysis confirmed the existence of a chemical bond between aluminum oxide and oleic acid. The outcomes of XRD analyses showed the presence of cubic gamma aluminum oxide in the nanocomposite, in contrast to the amorphous nature of PMMA. TEM images showed the core-shell morphology of the particles other than pristine PMMA. Optical constants of the nanocomposite were calculated based on FTIR spectra and the Kramers-Kronig equations. The presence of nano alumina modified some of the optical indexes in IR region.