Measurement of growth rates for single crystals and pressed tablets of CuSO4.5 H2O on a rotating disc

1989 ◽  
Vol 54 (11) ◽  
pp. 2951-2961 ◽  
Author(s):  
Miloslav Karel ◽  
Jaroslav Nývlt
Keyword(s):  
Growth Rate ◽  
Single Crystal ◽  
Single Crystals ◽  
Growth Rates ◽  
Diffusion Coefficients ◽  
Preferred Orientation ◽  
Rotating Disc ◽  
Dissolution Rates ◽  
Rates Of Growth ◽  
Good Agreement

Measured growth and dissolution rates of single crystals and tablets were used to calculate the overall linear rates of growth and dissolution of CuSO4.5 H2O crystals. The growth rate for the tablet is by 20% higher than that calculated for the single crystal. It has been concluded that this difference is due to a preferred orientation of crystal faces on the tablet surface. Calculated diffusion coefficients and thicknesses of the diffusion and hydrodynamic layers in the vicinity of the growing or dissolving crystal are in good agreement with published values.

Growth of AlN Single Crystals

1998 ◽  
Vol 512 ◽  
Author(s):  
Glen A. Slack
Keyword(s):  
Growth Rate ◽  
Aluminum Nitride ◽  
Single Crystal ◽  
Single Crystals ◽  
Dissociation Energy ◽  
Growth Rates ◽  
Growth Process ◽  
Limiting Factor ◽  
Crucible Material ◽  
Dissociation Pressure

ABSTRACTAluminum nitride is a wurtzite structure III–V compound, although epitaxial layers of zincblende structure AIN have been made. AlN melts congruently at 2750°C with dissociation pressure of 9 atmospheres. Boules of AIN have been successfully grown by a sublimation-recondensation technique at 2300°C employing tungsten crucibles. Growth rates of 0.3 mm per hour were attained at 1 bar pressure of N2, and crystals up to 22 mm long have been grown. An analysis of the growth process shows that the 9.75eV dissociation energy of N2is the limiting factor in the growth rate. The growth rate is predicted to depend on the N2pressure, but no experiments in this area have yet been concluded. The most satisfactory crucible material found so far for growing AIN is single crystal tungsten.

Comparison of copper sulphate pentahydrate growth rates determined by different methods

1990 ◽  
Vol 55 (7) ◽  
pp. 1691-1707 ◽  
Author(s):  
Miloslav Karel ◽  
Jiří Hostomský ◽  
Jaroslav Nývlt ◽  
Axel König
Keyword(s):  
Growth Rate ◽  
Crystal Growth ◽  
Fluidized Bed ◽  
Growth Rates ◽  
Copper Sulphate ◽  
Crystal Growth Rate ◽  
Effect Of Temperature ◽  
Rotating Disc ◽  
Shape Factors ◽  
Data Treatment

Crystal growth rates of copper sulphate pentahydrate (CuSO4.5 H2O) determined by different authors and methods are compared. The methods included in this comparison are: (i) Measurement on a fixed crystal suspended in a streaming solution, (ii) measurement on a rotating disc, (iii) measurement in a fluidized bed, (iv) measurement in an agitated suspension. The comparison involves critical estimation of the supersaturation used in measurements, of shape factors used for data treatment and a correction for the effect of temperature. Conclusions are drawn for the choice of values to be specified when data of crystal growth rate measurements are published.

The Relative Growth of Parts in Palaemon Carcinus

1930 ◽  
Vol 7 (2) ◽  
pp. 165-174
Author(s):  
M. A. TAZELAAR
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Linear Measurements ◽  
Relative Growth ◽  
Male And Female ◽  
Relative Growth Rates ◽  
Rate Of Growth ◽  
The Difference ◽  
Rates Of Growth

Linear measurements of certain appendages and the carapace of P. carcinus were made and plotted in various ways. The following conclusions were drawn: 1. The cheliped shows heterogonic growth in both male and female, but more markedly in the male, the values of k being: male 1.8 and female 1.48 2. The pereiopods in both male and female are slightly heterogonic. The relative growth rates are graded from p3 to p5, that of p3 being slightly greater than that of p5 3. Of the ordinary pereiopods the rate of growth of p1 is the smallest in the male, but the largest in the female. 4. The difference between the rates of growth of p1 and p3 in male and female is greatest where the rate of growth in the heterogonic organ, the cheliped, is most excessive in the male. 5. The growth of the 3rd maxilliped is slightly negatively heterogonic, the value of k in the male being 0.93 and in the female 0.95. Hence there seems to be a correlation between the marked heterogony in the cheliped on the growth rate of neighbouring appendages. In those immediately posterior to the cheliped the growth rate is increased and in those anterior decreased.

scholarly journals Effect of Composition on the Growth of Single Crystals of (1−x)(Na1/2Bi1/2)TiO3-xSrTiO3 by Solid State Crystal Growth

Materials ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2357 ◽  
Author(s):  
Le ◽  
Fisher ◽  
Moon
Keyword(s):  
Growth Rate ◽  
Crystal Growth ◽  
Solid State ◽  
Single Crystal ◽  
Single Crystals ◽  
Grain Growth ◽  
Ceramic Powder ◽  
Single Crystal Growth ◽  
Crystal Growth Rate ◽  
Mixed Control

The (1−x)(Na1/2Bi1/2)TiO3-xSrTiO3 (NBT-100xST) system is a possible lead-free candidate for actuator applications because of its excellent strain vs. electric field behaviour. Use of single crystals instead of polycrystalline ceramics may lead to further improvement in piezoelectric properties but work on single crystal growth in this system is limited. In particular, the effect of composition on single crystal growth has yet to be studied. In this work, single crystals of (NBT-100xST) with x = 0.00, 0.05, 0.10 and 0.20 were grown using the method of Solid State Crystal Growth. [001]-oriented SrTiO3 single crystal seeds were embedded in (NBT-100xST) ceramic powder, which was then pressed to form pellets and sintered at 1200 °C for 5 min–50 h. Single crystal growth rate, matrix grain growth rate and sample microstructure were examined using scanning and transmission electron microscopy. The results indicate that the highest single crystal growth rate was obtained at x = 0.20. The mixed control theory of grain growth is used to explain the single crystal and matrix grain growth behaviour.

Relationship between growth rate and undercooling in Pt-added Y1Ba2Cu3O7−x

1996 ◽  
Vol 11 (5) ◽  
pp. 1114-1119 ◽  
Author(s):  
A. Endo ◽  
H. S. Chauhan ◽  
Y. Nakamura ◽  
Y. Shiohara
Keyword(s):  
Experimental Data ◽  
Growth Rate ◽  
Parabolic Equation ◽  
Growth Rates ◽  
Crystal Size ◽  
Experimental Conditions ◽  
Seed Crystals ◽  
Cooling Method ◽  
Increasing Trend ◽  
Good Agreement

Y1Ba2Cu307−x (Y123) crystals were grown by two different methods, the constant undercooling solidification and the continual cooling method, with top seeding by Sm123 seed crystals in order to investigate a relationship between undercooling (ΔT) and a growth rate (R). The crystals of Y123 with a sharp faceted interface, which consisted of {100} and {001} faces, grew epitaxially from the seed. It was found that the growth rates of {100} face (Ra) and that of {001} face (Rc) showed an increasing trend with increasing ΔT, and Rc was faster than Ra within these experimental conditions, ΔT < 20 K. The relation between R and ΔT follows the parabolic equation, viz. Ra ∝ ΔT1.9 and Rc ∝ ΔT1.3 for {100} and {001} faces, respectively. The simulated crystal size using the R and ΔT relations obtained from the constant undercooling method showed good agreement with experimental data by the continual cooling.

scholarly journals Environmental and Life-history Factors Influencing  Juvenile Demography of a Temperate Reef Fish

2021 ◽  
Author(s):  
◽  
Anna Clare Smith
Keyword(s):  
Growth Rate ◽  
Reef Fish ◽  
Growth Rates ◽  
Juvenile Growth ◽  
Growth And Survival ◽  
Temperate Reef ◽  
Habitat Composition ◽  
Temperate Reef Fish ◽  
Rates Of Growth ◽  
Larval Traits

<p>Realistic population models and effective conservation strategies require a thorough understanding of the processes that drive variation in individual growth and survival, particularly within life stages that are subject to high mortality. For fragmented marine populations it is also important to consider how processes driving variation performance may vary through space and time. In this study I assess the interaction of two primary factors driving juvenile demography: benthic habitat composition and larval history traits, in a temperate reef fish, Forsterygion lapillum (the common triplefin). It is well understood that juveniles of many marine organisms are closely associated with structured nearshore habitats as they provide resources (refuge and food sources) that are critical for juvenile growth and/or survival. Nursery habitats are often assessed using measures of fitness of juveniles inhabiting them (e.g. rates of growth). However individual fitness measures may not only be indicative of conditions experienced in the benthic phase, but also an individual's prior history. Recent evidence suggests that variation in larval traits at settlement (e.g., size and age at settlement, larval growth rate) can impact on subsequent ecological performance (e.g., feeding ability and/or predator avoidance) and therefore influence subsequent fitness (i.e. rates of growth and/or probabilities of survival). I used otolith microstructure to assess separate and joint effects of habitat composition and larval traits on the growth of young F. lapillum. Both macroalgal composition of habitat patches and larval traits affected juvenile growth rates, and results suggested that habitat composition may have the potential to mediate fitness-related advantages that may accrue to certain individuals as a result of paternal effects and/or larval dispersal history. Quantifying spatio-temporal variability in the post-settlement fitness of Individuals with that differ in larval traits is essential for effective spatial management of marine populations. I further explore the joint effects of macroalgal composition and larval traits, within the context of additional spatial and temporal environmental variation. Results provide direct evidence that habitat can mediate the strength of carryover effects, but that the impact of habitat was variable between local populations and settlement events through time. In chapter 4 of my thesis, I focus on how small-scale variation in macroalgal composition within a nursery habitat (while controlling for individual variation) can affect the strength of density dependent growth and survival rates of F. lapillum. Density-dependent survival is evident during the first 30 days after settlement, and the strength of density dependence varied as a function of macroalgal composition. Resulting variation in estimates of nursery value (i.e., the number of late-stage juveniles produced per area unit of habitat) highlight the importance of incorporating local scale variation in juvenile demography into assessments of nursery habitat. Lastly, I assess a potential strategy of fishes to persist in a wide range of benthic environments. The ability to adjust traits (i.e., phenotypic plasticity) may allow organisms that encounter a range of unpredictable environmental conditions to maximise fitness within a single generation. In chapter 5 I explore patterns of variation in morphology of juvenile F. lapillum from two different subpopulations and from different macroalgal habitats. I evaluate possible evidence for constraints on morphological variation arising from variation in growth rate prior to and following settlement. Results suggest that for organisms with complex life cycles, variation in growth rates experienced during dispersal may constrain plasticity in later stages.</p>

scholarly journals Environmental and Life-history Factors Influencing  Juvenile Demography of a Temperate Reef Fish

2021 ◽  
Author(s):  
◽  
Anna Clare Smith
Keyword(s):  
Growth Rate ◽  
Reef Fish ◽  
Growth Rates ◽  
Juvenile Growth ◽  
Growth And Survival ◽  
Temperate Reef ◽  
Habitat Composition ◽  
Temperate Reef Fish ◽  
Rates Of Growth ◽  
Larval Traits

<p>Realistic population models and effective conservation strategies require a thorough understanding of the processes that drive variation in individual growth and survival, particularly within life stages that are subject to high mortality. For fragmented marine populations it is also important to consider how processes driving variation performance may vary through space and time. In this study I assess the interaction of two primary factors driving juvenile demography: benthic habitat composition and larval history traits, in a temperate reef fish, Forsterygion lapillum (the common triplefin). It is well understood that juveniles of many marine organisms are closely associated with structured nearshore habitats as they provide resources (refuge and food sources) that are critical for juvenile growth and/or survival. Nursery habitats are often assessed using measures of fitness of juveniles inhabiting them (e.g. rates of growth). However individual fitness measures may not only be indicative of conditions experienced in the benthic phase, but also an individual's prior history. Recent evidence suggests that variation in larval traits at settlement (e.g., size and age at settlement, larval growth rate) can impact on subsequent ecological performance (e.g., feeding ability and/or predator avoidance) and therefore influence subsequent fitness (i.e. rates of growth and/or probabilities of survival). I used otolith microstructure to assess separate and joint effects of habitat composition and larval traits on the growth of young F. lapillum. Both macroalgal composition of habitat patches and larval traits affected juvenile growth rates, and results suggested that habitat composition may have the potential to mediate fitness-related advantages that may accrue to certain individuals as a result of paternal effects and/or larval dispersal history. Quantifying spatio-temporal variability in the post-settlement fitness of Individuals with that differ in larval traits is essential for effective spatial management of marine populations. I further explore the joint effects of macroalgal composition and larval traits, within the context of additional spatial and temporal environmental variation. Results provide direct evidence that habitat can mediate the strength of carryover effects, but that the impact of habitat was variable between local populations and settlement events through time. In chapter 4 of my thesis, I focus on how small-scale variation in macroalgal composition within a nursery habitat (while controlling for individual variation) can affect the strength of density dependent growth and survival rates of F. lapillum. Density-dependent survival is evident during the first 30 days after settlement, and the strength of density dependence varied as a function of macroalgal composition. Resulting variation in estimates of nursery value (i.e., the number of late-stage juveniles produced per area unit of habitat) highlight the importance of incorporating local scale variation in juvenile demography into assessments of nursery habitat. Lastly, I assess a potential strategy of fishes to persist in a wide range of benthic environments. The ability to adjust traits (i.e., phenotypic plasticity) may allow organisms that encounter a range of unpredictable environmental conditions to maximise fitness within a single generation. In chapter 5 I explore patterns of variation in morphology of juvenile F. lapillum from two different subpopulations and from different macroalgal habitats. I evaluate possible evidence for constraints on morphological variation arising from variation in growth rate prior to and following settlement. Results suggest that for organisms with complex life cycles, variation in growth rates experienced during dispersal may constrain plasticity in later stages.</p>

Dynamic Shear Stress—Analysis of Single Crystal Machining Studies

1973 ◽  
Vol 95 (4) ◽  
pp. 939-944 ◽  
Author(s):  
S. Ramalingam ◽  
J. Hazra
Keyword(s):  
Shear Stress ◽  
Single Crystal ◽  
Stress Analysis ◽  
Single Crystals ◽  
Plastic Flow ◽  
Metal Cutting ◽  
Dynamic Shear ◽  
Polycrystalline Aluminum ◽  
Cutting Problem ◽  
Good Agreement

Experimental results obtained when single crystals of aluminum of known orientation are machined under identical cutting conditions are presented. Analysis of the data obtained shows that the dynamic shear stress remains constant for all orientations tested and is in good agreement with the calculated value for polycrystalline aluminum. The implications of these results to metal cutting theory and the metal physical foundations on which the concept of dynamic shear stress, as a true material property, rests are discussed. The possible role that the dynamic shear stress may play in determining the geometry of the metal cutting problem, a problem in partially constrained plastic flow of metals, is discussed.

Liveweight gain of weaned lambs grazing swards increasing, decreasing or at constant surface heights.

1987 ◽  
Vol 1987 ◽  
pp. 39-39
Author(s):  
J.M. Doney ◽  
J. A. Milne ◽  
I.R. White ◽  
Mary Lloyd
Keyword(s):  
Growth Rate ◽  
Weight Gain ◽  
Growth Rates ◽  
Live Weight ◽  
Nutrient Requirements ◽  
Milk Supply ◽  
Sward Height ◽  
Herbage Intake ◽  
Rates Of Growth ◽  
Lamb Growth

During the early grazing season, when a high proportion of the lambs nutrient requirements are supplied by milk, high rates of growth can be achieved by sward management which maintains a constant surface height (3-5.5 cm) (Maxwell, Lloyd and Dickson, 1985). In late lactation, increasing herbage Intake rarely compensates for reduced milk supply and lamb growth rates are commonly lower than could be achieved with concentrate diets (Doney et al, 1984; Lloyd et al 1987). Lamb growth in this period may be related to increase or decrease of sward height (Alcock, Clark and Harvey, 1986; Maxwell, Lloyd and Dickson, 1985) or to changes in herbage growth rate (Doney, Smith, Sim and White, 1986). The present study investigated the effect on daily live-weight gain (DLWG) in weaned lambs of herbage growth rate (HGR) and pattern of sward height (SH) change when varied independently.

Interphase Boundary Diffusion in Eutectic Alloys

1985 ◽  
Vol 57 ◽  
Author(s):  
G. A. Chadwick
Keyword(s):  
Diffusion Coefficient ◽  
Single Crystal ◽  
Single Crystals ◽  
Interphase Boundary ◽  
Diffusion Coefficients ◽  
Noble Metals ◽  
Boundary Diffusion ◽  
Eutectic Alloys ◽  
Self Diffusion ◽  
Interphase Boundaries

AbstractTurnbull and co-workers have shown that the noble metals Cu, Ag, and Au diffuse into single crystals of Pb and Sn by an interstitialcy mechanism with measured diffusion coefficients of ∼10−6cm2s−1. These experiments have been extended to study the diffusion rates of the noble metals along the interphase boundaries of single crystal of Pb-Sn eutectic alloys and to measure the diffusion coefficient of silver along the interphase boundaries of Ag-Cu eutectic single crystals.The measured interphase boundary diffusion coefficients of the noble metals in the Pb-Sn single crystals are extremely high, being 2.6 × 10−3cm2s−1for Cu and ∼10−4cm2s−1for Ag and Au at room temperature. These results again imply an interstitialcy mechanism of diffusion at the interphase boundaries. In contrast, the diffusion coefficient of Ag110in a Ag-Cu eutectic single crystal worked out to be ∼8×10−9cm2s−1at 500°C, two orders of magnitude lower than the value obtained by Turnbull and Hoffman for self-diffusion along low-angle (8∼10°) boundaries in silver.

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