• Title/Summary/Keyword: Molt temperature

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Survival Rate and Growth of Palaemon gravieri Larvae Reared in the Laboratory (Decapoda: Caridea: Palaemonidae)

  • Kim, Sung-Han
    • Fisheries and Aquatic Sciences
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    • v.8 no.2
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    • pp.90-96
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    • 2005
  • The larvae of Palaemon gravieri were reared in the laboratory at three different temperature regimes ($15^{\circ}C,\;20^{\circ}C,\;and\;25^{\circ}C$) with the salinity ranges (28-32 psu) to understand how temperature and body size influence survival rate, and growth components (molt increment and intermolt period). The optimum temperature for the highest survival rate was $25^{\circ}C$. The intermolt periods consistently increased with an increase in size and instar number; however, the molt increments at successive instars generally decreased with an increase in size and instar number. The shortest intermolt period and the highest larval growth rate both occurred at $25^{\circ}C$. Thus, the optimum temperature for larval survival and growth rate was found to be $25^{\circ}C$ which was the temperature at which the larvae actually appear in nature.

Study on the Reproductive Biology of the Giant Freshwater Prawn, Macrobrachium rosenbergii (De Man) 1. Molting Behavior and Effect of Rearing Termperature on Molt (대형 담수산새우, Macrobrachium rosenbergii (De Man)의 생식생리에 관한 연구 I. 탈피행동과 수온이 탈피에 미치는 영향)

  • 권진수
    • Development and Reproduction
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    • v.1 no.2
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    • pp.173-180
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    • 1997
  • This study has been conducted to investigate the molting behavior and the effects of rearing temperature and day length on molting in the behavior and the effects of rearing temperature and day length on molting in the giant freshwater prawn, Macrobrachium rosenbergii reared in the laboratory. The results obtained were summarized as follow: 1. After pre-spawning molting, the protopodites of 1st, 2nd, 3rd, and 4th except 5th pleopod bore new breeding setae which conserve eggs in the brooding chamber and the basis of 3rd, 4th, and 5th pereiopods bore new breeding dresses which transport the ovulated eggs into the brooding chamber. 2. Adult females reared in 27.5-$29.4^{\circ}C$ molted 10-12 times per year at interval of 27-35 days, of which four or six moltings were common molting for growth and another four or five moltings were pre-spawning molting for spwaning and brooding. In winter season, pre-spawning molting did not happen to most of adult females in spite of the same temperature. 3. Duration of intermolt cycle was 31-38 days and 26-30 days at 25.3- $26.5^{\circ}C$ and 28.7- $30.4^{\circ}C$ of rearing temperature, respectively.

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Effects of Rearing Temperature on Larval Survival and Growth and on Reproductive Traits of Palaemon serrifer (Decapoda: Caridea: Palaemonidae)

  • Kim, Sung-Han
    • Fisheries and Aquatic Sciences
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    • v.13 no.4
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    • pp.308-314
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    • 2010
  • Larvae of Palaemon serrifer were reared in the laboratory under three different temperature regimes ($15^{\circ}C$, $20^{\circ}C$, $25^{\circ}C$) to study the effects of rearing temperature on larval survival and growth, as well as other traits such as embryo volume, number of embryos (fecundity), incubation period, development. Mode and development period. Growth pattern was analyzed by measuring the molt increment and intermolt period. The intermolt period consistently increased with size and instar number and was shortest at $25^{\circ}C$. However, molt increments generally decreased with instar number. Number of embryos varied from 552 to 1355. The relationship between the number of embryos and carapace length was expressed by the equation (fecundity) y=2.7744x+0.208 ($R^2$=0.7961). Egg volume was a primary factor affecting other life-history traits. Egg volume was $0.078\;m^3$, which is relatively small thus embryos exhibited a relatively short incubation period and a comparatively short development period, and the nutritional mode was planktotrophic. Brood production was followed by a fast parturitional pattern. Most ovigerous females had mature ovaries when the parturial molt occurred soon after eclosion.

Effects of Temperature on Larval Growth and Survival in the Wrinkled Swimming Crab (Liocarcinus corrugatus) (Brachyura: Portunidae) Reared in the Laboratory (주름꽃게 (Liocarcinus corrugatus) 유생의 성장과 생존에 대한 온도의 영향)

  • KIM Kwang Bong;HONG Sung Yun
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.37 no.3
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    • pp.186-191
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    • 2004
  • The effects of temperature on the growth of larvae of wrinkled swimming crab (Liocarcinus corrugatus) under controlled laboratory conditions of 15, 20 and $24^{\circ}C$ were investigated (33.5 psu: 12L: 12B). Each specimen was maintained individually, the instar size was determined from exuvia, and the survival and intermolt period of each instar were recorded. There were no significant differences (P>0.05) in the survival rates at 15, 20, and $24^{\circ}C.$ Comparison of survival over the first 27 days between the three temperature regimes showed significant differences (P<0.001). The intermolt period increased with the instar number, and was greatly extended at the lowest temperature. The molt increment varied little with temperature, and had a mean value of $21.35\%$ over the whole study. Temperature had little effect on survival and molt increment.

A Study on Intelligent Generator of Mold Temperature Using Fuzzy Algorithm to Prevent Short Shot (퍼지 알고리듬을 이용한 금형 온도 지적생성 시스템에 관한 연구)

  • 강성남;허용정
    • Journal of the Microelectronics and Packaging Society
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    • v.8 no.4
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    • pp.53-57
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    • 2001
  • A short shot is an incomplete molded part caused by insufficient material injection into the mold. Remedial actions to control the process conditions can be taken by injection molding experts based on their knowledge and experiences. However, it is very difficult for non-experts to avoid short shot by finding the proper process conditions such as mold temperature, melt temperature and filling time. In this paper, an intelligent generator of optimal process conditions based upon fully logic algorithm is proposed so that trial and error can be minimized and non-experts an well at experts can also find the optimal process conditions.

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Evaluation of Several Parameters of in situ Polymerase Chain Reaction (ISPCR) to Reduce the Leakage of Amplificants from Cells

  • Lee, Jae-Yung;Auh, Chung-Kyoon;George W. Jordan
    • Journal of Microbiology
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    • v.40 no.1
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    • pp.70-76
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    • 2002
  • Proviral DNAs from HIV-1-infected CD4+ T cells (Molt/LAV cells) were amplified and detected in infected individual cells using polymerase chain reaction and in rifu hybridization. In this in situ PCR, three parameters were considered to achieve effective amplification and retention of amplificants inside the cells by making high molecular weight PCR products intracellularly, forming agarose matrix against the cells, and maintaining the appropriate PCR temperature profile. Over the cycles of ampliHcationl tailed primers with complementary overhanging sequences at their 5' sides manufactured high molecular weight products by using short primary products as a repeating unit. Agarose matrix could prevent the diffusion of the amplificants from the cells. Use of Thermanox coverslip inside the PCR tube offered target cells a similar temperature profile to that of conventional PCR in solution.

Shrinkage in Injection Molded Part for Operational Conditions and Resins (성형조건과 수지의 종류에 따른 사출 성형품의 성형 수축)

  • Mo, Jung-Hyuk;Chung, Wan-Jin;Lyu, Min-Young
    • Elastomers and Composites
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    • v.38 no.4
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    • pp.295-302
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    • 2003
  • The amount of shrinkage of injection molded parts is different from operational conditions of injection molding such as injection temperature, injection pressure and mold temperature, and mold design such as gate size. It also varies depending on the presence of crystalline structure in resins. In this study, part shrinkage was investigated for various operational conditions and resins. Poly(butylene terephthalate) (PBT) for crystalline polymer, and polycarbonate (PC) and poly(methyl methacrylate) (PMMA) for amorphous polymers were used. Crystall me polymer showed higher part shrinkage by about three times than that of amorphous polymers. Part shrinkage increased as melt and molt temperatures increased, and injection pressure decreased. Part shrinkage decreased as gate size increased since the pressure delivery is mush easier for larger gate sizes. Part shrinkage at the position close to the gate was larger than that or the position far from gate. This phenomenon might be occur by difference of residual stress.

An Experimental Study for Basic Properity of Ultra High-strength Concrete (초고강도 콘크리트의 기초물성에 관한 실험적 연구)

  • Kim Ji-Man;Gong Min-Ho;Yang Dong-Il;Jung Sang-Jin
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2006.05a
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    • pp.39-42
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    • 2006
  • Recently, more highly effective construction materials are needed for the reasonable and economical structure system is required as the construction structures become more multi storied, large-sized and diversified. That is to say, the highly qualified concrete, the molt universal construction material is positively promoted as a part of plan to establish the effective space according to the dead load of structures and diminish of segment profile and to build up the economic structures. In particular, it is tendency of that the study for high strength concrete increases and construction example of reinforced concrete (RC) using the high strength concrete partially increases. However, the high strength concrete has the problems such high brittleness and low ductility. Specially, for the high strength concrete, it has different strength from normal concrete as the internal temperature goes up steadily due to high heat of hydration by the quantities of highly level of cement, so the concrete which is mixed with various scible materials is used. This study conducted a basic experiment to conclude an adequate selection of materials and to calculate an optimal mixing proportion of those materials to produce High-strength concrete. And also we conducted an experiment to find out basic properties of this concrete such as slump-flow, strength.

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Studies on the Growth and Molting of the Tiger Crab, Orithyia sinica (Linnaeus) (범게, Orithyia sinica (Linnaeus)의 성장과 탈피에 관한 연구)

  • KIM Young-Ho;CHUNG Sang-Chul
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.23 no.2
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    • pp.93-108
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    • 1990
  • Complete larval development Orithyia sinica (Linnaeus) is composed of three zoeal ins-tars and megalopa. Survival of instals was higher in $20^{\circ}C$ than in ambient temperature. Intermolt period generally increased with the increase of number of instals, but a notable decrease was observed from Crab-5 to prepuerty molt instals(Crab-7). Zoeas and me-galopa reared at higher temperature regime were samller than those reared at lower temperature. No temperature effect was shown in the size of crab instals. Growth factors fluctuate with the increase of number of instals, but there was an overall trend of net decrease. Growth factor was $35.65\~41.4\%$ for zoeal instals, and they were $18.00\~30.91\%$ for crab instals.

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Corrosion Behavior of Superalloys in Hot Molten Salt under Oxidation Atmosphere (고온용융염계 산화분위기에서 초합금의 부식거동)

  • 조수행;임종호;정준호;이원경;오승철;박성원
    • Proceedings of the Korean Radioactive Waste Society Conference
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    • 2004.06a
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    • pp.285-291
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    • 2004
  • As a part of assessment of the structural material for the molten salt handling system, corrosion behavior of Inconel 718, X-750, Haynes 75 and Haynes 263 alloys in the molten salt of LiCl-Li$_2$O-O$_2$was investigated in the range of temperature; $650^{\circ}C$, time; 24~168h, $Li_2O$; 3wt%, mixed gas; Ar~10%$O_2$. In the molten salt of LiCl-$Li_2O-O_2$, the order corrosion rate was Haynes 263 < Haynes 75 < Inconel X-750 < Inconel 718. Haynes 263 alloy showed the highest corrosion resistance among the examined alloys. Corrosion products of alloys were as fellows: Haynes 75: $Cr_2O_4$, $NiFe_2O_4$, $LiNiO_2$, $Li_2NiFe_2O_4$, Inconel 718; $Cr_2O_4$, $NiFe_2O_4$, Haynes 263; $Li(Ni,Co)O_2$, $NiCr_2O_4$, $LiTiO_2$, Inconel X-750; $Cr_2O_3$, $NiFe_2O_4$,$FeNi_3$, (Al,Nb,Ti)$O_2$. Haynes 263 showed local corrosion behavior and Haynes 75, Inconel 718 and Inconel X-750 showed uniform corrosion behavior.

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