TEMPERATURE-CONTROLLED MERISTIC VARIATION IN THE PARADISE FISH MACROPODUS OPERCULARS (L.)

1954 ◽  
Vol 32 (2) ◽  
pp. 87-98 ◽  
Author(s):  
C. C. Lindsey
Keyword(s):  
High Temperature ◽  
High Temperatures ◽  
Environmental Influence ◽  
The Other ◽  
General Tendency ◽  
Fin Ray ◽  
Final Count ◽  
Meristic Variation ◽  
Temperature Controlled ◽  
Paradise Fish

Eggs from one pair of paradise fish Macropodus opercularis (L.) were reared at different constant temperatures, and the effects were noted on dorsal and anal fin ray, spine and basal counts, caudal and pectoral ray counts, and vertebral counts. Some young were transferred from low to high temperatures after varying periods to determine the duration of sensitivity of meristic series to environmental influence. Intermediate sustained temperature produced significantly fewer vertebrae than either low or high temperature. Different rearing temperatures produced different ray, spine, and basal counts; variation in each of these series was largely independent of vertebral variation and of variation in the other series. Eggs hatched less than two days after fertilization, but some meristic series were still subject to environmental influence 20 days later. The order of fixation of the final count in different series roughly followed the order of their ontogenetic appearance. While "shock effect" was apparent in some changes produced by temperature transfers, there was a general tendency for counts of certain lots of fish transferred from low to high temperature to approximate counts of fish reared at sustained intermediate temperatures.

High Temperature Implantation in Graphite

1983 ◽  
Vol 27 ◽  
Author(s):  
G. Braunstein ◽  
B.S. Elman ◽  
M.S. Dresselhaus ◽  
G. Dresselhaus ◽  
T. Venkatesan
Keyword(s):  
High Temperature ◽  
Radiation Damage ◽  
High Temperatures ◽  
Room Temperature ◽  
Pyrolytic Graphite ◽  
Rutherford Backscattering ◽  
The Other ◽  
Highly Oriented Pyrolytic Graphite ◽  
Graphite Lattice ◽  
Partial Annealing

ABSTRACTIn previous studies it was found that when highly oriented pyrolytic graphite (HOPG) is implanted at room temperature, the damage caused by the implantation could be completely annealed by heating the sample to temperatures higher than ∼ 2500°C. However at these high temperatures, the implanted species was found to diffuse out of the sample, as evidenced by the disappearance of the impurity peak in the Rutherford backscattering (RBS) spectrum. If, on the other hand, the HOPG crystal was held at a high temperature (≥ 600°C) during the implantation, partial annealing could be observed. The present work further shows that it is possible to anneal the radiation damage and simultaneously to retain the implants in the graphite lattice by means of high temperature implantation (Ti ≥ 450°C) followed by annealing at 2300°C.

OBSERVATIONS ON MERISTIC VARIATION IN NINESPINE STICKLEBACKS, PUNGITIUS PUNGITIUS, REARED AT DIFFERENT TEMPERATURES

1962 ◽  
Vol 40 (7) ◽  
pp. 1237-1247 ◽  
Author(s):  
C. C. Lindsey
Keyword(s):  
High Temperature ◽  
Gasterosteus Aculeatus ◽  
Pungitius Pungitius ◽  
Pectoral Fin ◽  
Vertebral Count ◽  
Fin Ray ◽  
Fin Rays ◽  
Different Temperatures ◽  
Meristic Variation ◽  
Pectoral Fin Rays

Eggs of 10 pairs of wild ninespine sticklebacks from Hobson's Brook near Cambridge, England, were reared under various controlled temperatures. Temperature for optimum survival to hatching differed between genotypes. Ninety young were examined for counts of vertebrae, spines, and dorsal, anal, and pectoral fin rays. Survivors at high temperature had markedly more vertebrae than survivors at low. Curves of temperature against vertebral count may be V-shaped for each genotype, and optimum survival temperature may produce lowest vertebral count. More basal supports to the dorsal and anal fins and spines were produced at high temperature. Disruptions in one-to-one serial conformity between ray or spine, basal, and vertebral series became progressively commoner at higher rearing temperatures. Parents showed positive correlation between dorsal and anal fin ray counts and number of caudal scutes. Comparisons are made with Gasterosteus aculeatus.

In Situ Study of Zirconia Stabilization by Anion Exchange (N for O) Using High-Temperature, Controlled Atmosphere Electron Diffraction

1999 ◽  
Vol 589 ◽  
Author(s):  
Renu Sharma ◽  
Eberhard Schweda ◽  
Dirk Naedele
Keyword(s):  
High Temperature ◽  
Electron Diffraction ◽  
Anion Exchange ◽  
High Temperatures ◽  
Controlled Atmosphere ◽  
In Situ Study ◽  
Environmental Cell ◽  
Temperature Controlled ◽  
Cubic Structure

AbstractStabilization of zirconia by anion exchange (N for O) is a novel idea. A number of oxy-nitrides with flourite-related (cubic) structure have been reported to form at high temperatures (1100°C). We have used a TEM equipped with environmental cell and Gatan Imaging Filter (GIF) to study the nitridation behavior of zirconia. The in situ observations reveal the formation of a cubic structure at ≈800°C when the Zr(OH) 4×H2O precursor was heated in ≈2 torr of NH3. The presence of N in the lattice is confirmed by electron energyloss spectroscopy.

A Study of Ta2O5 for use as High Temperature Piezoelectric Sensors

1996 ◽  
Vol 459 ◽  
Author(s):  
B. R. Jooste ◽  
H. J. Viljoen
Keyword(s):  
High Temperature ◽  
High Temperatures ◽  
Piezoelectric Effect ◽  
Xrd Analysis ◽  
The Other ◽  
Piezoelectric Sensors ◽  
Qualitative Assessment ◽  
Acoustic Sensors

ABSTRACTAcoustic sensors which can function at high temperatures have important potential uses. In this work we report on the deposition, characterization and qualitative assessment of piezoelectric behaviour of orthorhombic Ta2O5• It is shown that orthorhombic Ta2O5 belongs to the class 2mm. XRD analysis of films annealed for 1 min., 10 min. and 1 hr at 800°C and 900°C reveal the formation of (0 0 1), (1 10 0) and (1 11 0) orientations at 800 °C, but the (1 10 0) increases at the expense of the other two as the annealing period is extended. At 900°C the dominant orientations are (1 10 0) and (2 9 0). The piezoelectric effect is significantly stronger after annealing and the stronger piezoelectric effect does not correlate with the presence of (1 10 0) and (2 9 0) so much as with the absence of (0 0 1) and (1 11 0).

Comparison of a Current Mode Reference Generator vs.a ΔVBE Bandgap Circuit in a 1.0μm Partially-Depleted Silicon-On-Insulator CMOS Process for High Temperature (220 °C) Environments

2017 ◽  
Vol 2017 (HiTEN) ◽  
pp. 000234-000237
Author(s):  
Alex Pike ◽  
Adrien Corne ◽  
Frank Bohac ◽  
Ravi Ananth
Keyword(s):  
High Temperature ◽  
High Temperatures ◽  
Wide Temperature Range ◽  
Output Voltage ◽  
Current Mode ◽  
Silicon On Insulator ◽  
The Other ◽  
Cmos Process ◽  
Reference Generator ◽  
A Current

Abstract Two different reference generator circuits were designed, fabricated and tested, on the same silicon die using a 1.0μ CMOS SOI process that is suitable for operation at high temperatures. One of the reference generators was a traditional bandgap circuit. The other was a more novel current-mode reference that can notionally generate any output voltage. Testing was performed over a wide temperature range from −50°C to 220°C with a supply variation of 4V to 6V.

High-Temperature Oxidation Resistance and Crack-Healing Function of Ni/Al2O3 Nano-Hybrid Materials

2010 ◽  
Vol 638-642 ◽  
pp. 2148-2153 ◽  
Author(s):  
Makoto Nanko
Keyword(s):  
High Temperature ◽  
Oxidation Resistance ◽  
High Temperatures ◽  
Hybrid Materials ◽  
High Temperature Oxidation ◽  
The Other ◽  
High Temperature Annealing ◽  
Crack Healing ◽  
Temperature Oxidation ◽  
Co Dispersion

High-temperature oxidation resistance of Ni/Al2O3 nano-hybrid materials was described in this paper. Y2O3 doping and SiC co-dispersion in Ni/Al2O3 nano-hybrid materials are useful techniques to improve high-temperature oxidation resistance. On the other hand, nano-Ni/Al2O3 has the crack healing function by high-temperature annealing in air. SiC-Ni/Al2O3 nano-hybrid materials have similar crack healing performance with better oxidation resistance at high temperatures than Ni/Al2O3 nano-hybrid materials.

scholarly journals Influences of high temperature on mechanical properties of fly ash based geopolymer mortars reinforced with PVA fiber

2021 ◽  
Vol 20 (2) ◽  
pp. 393-406
Author(s):  
Mehmet Kaya ◽  
◽  
Fuat Köksal ◽  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
High Temperature ◽  
Fly Ash ◽  
High Temperatures ◽  
Physical And Mechanical Properties ◽  
The Other ◽  
Polyvinyl Alcohol Fiber ◽  
Pva Fiber ◽  
High Temperature Effect

In this study, a geopolymer composite containing PVA fiber was produced to recycle waste fly ash and obtain an eco-friendly binder. Mechanical properties of geopolymer mortars, produced by using F class fly ash which was activated with NaOH (sodium hydroxide), and reinforced by PVA (polyvinyl alcohol) fiber were investigated after high temperature effect. Geopolymer mortar samples produced by mixing with fly ash, sand, water and NaOH were placed in standard molds of 40×40×160 mm3. PVA fibers were used at percentages of 0,5%, 1% and 1,5% by volume in the experiment. Tests were performed on mortars exposed to high temperatures of 200°C, 400°C, 600°C and 800°C for physical and mechanical properties. For the specimens not subjected to high temperatures, an increase in the compressive strength of mortars containing PVA fibers was observed in comparison to mortar without PVA fiber. On the other hand, it was concluded that losses in compressive strength were less for mortar without PVA fiber when compared with the mortars containing PVA fibers. As a result of the modeling, the PVA ratio, which gives the optimum flexural and compressive strength, was determined as 1,47%. As a result of melting of PVA fibers under the effect of high temperature, 83,58% loss of compressive strength was determined in samples containing 1,5% PVA after 800ºC temperature.

scholarly journals Ammonia decomposition catalysis using lithium–calcium imide

2016 ◽  
Vol 188 ◽  
pp. 525-544 ◽  
Author(s):  
Joshua W. Makepeace ◽  
Hazel M. A. Hunter ◽  
Thomas J. Wood ◽  
Ronald I. Smith ◽  
Claire A. Murray ◽  
...  
Keyword(s):  
High Temperature ◽  
High Temperatures ◽  
Powder Diffraction ◽  
Light Metal ◽  
Reaction Mass ◽  
Ammonia Decomposition ◽  
The Other ◽  
Lithium Amide ◽  
Lithium Imide

Lithium–calcium imide is explored as a catalyst for the decomposition of ammonia. It shows the highest ammonia decomposition activity yet reported for a pure light metal amide or imide, comparable to lithium imide–amide at high temperature, with superior conversion observed at lower temperatures. Importantly, the post-reaction mass recovery of lithium–calcium imide is almost complete, indicating that it may be easier to contain than the other amide–imide catalysts reported to date. The basis of this improved recovery is that the catalyst is, at least partially, solid across the temperature range studied under ammonia flow. However, lithium–calcium imide itself is only stable at low and high temperatures under ammonia, with in situ powder diffraction showing the decomposition of the catalyst to lithium amide–imide and calcium imide at intermediate temperatures of 200–460 °C.

Sexual behaviour and semen characteristics of boars: effects of high temperature

1981 ◽  
Vol 21 (108) ◽  
pp. 39 ◽  
Author(s):  
CG Winfield ◽  
PH Hemsworth ◽  
DB Galloway ◽  
AW Makin
Keyword(s):  
High Temperature ◽  
High Temperatures ◽  
Sexual Behaviour ◽  
The Other ◽  
Temperature Cycle ◽  
Large White ◽  
Air Temperatures ◽  
Semen Characteristics ◽  
Hot Weather ◽  
Copulatory Behaviour

The effect of 4,7 or 10-day periods of high air temperatures on the sexual behaviour and semen characteristics of mature Large White crossbred boars was determined in three experiments. In experiment 1, boars kept at 40�C for 8 hours and 30�C for 16 hours each day for 7 days had lower courting behaviour activity when tested at 40�C than control boars tested at <25�C. After similar heat treatment in experiment 2, boars tested at 30�C showed no significant differences in courting or copulatory behaviour from control boars, but the semen of two of six treated boars showed evidence of severe testicular- epididymal dysfunction. The semen of a third treated boar showed evidence of moderate testicular-epididymal dysfunction. In experiment 3, four boars were given a similar daily high temperature cycle to the above, either for 4 or 10 days. Two of the four boars given high temperatures for 10 days had semen with signs of severe testicular-epididymal dysfunction. The semen of the other two boars in this group, and one boar treated for 4 days, showed evidence of moderate dysfunction. It was concluded that during hot weather boars will mate normally during the cooler part of the day, and that they are able to tolerate short periods of heat stress (< 4 days) without detriment to semen characteristics. Protection from longer periods of high temperatures ( > 7 days) is necessary.

High Temperature n- and p-type Doped Microcrystalline Silicon Layers Grown by VHF PECVD Layer-by-Layer Deposition

2003 ◽  
Vol 762 ◽  
Author(s):  
A. Gordijn ◽  
J.K. Rath ◽  
R.E.I. Schropp
Keyword(s):  
Activation Energy ◽  
High Temperature ◽  
High Temperatures ◽  
Continuous Wave ◽  
Hydrogen Plasma ◽  
Silicon Layer ◽  
Dark Conductivity ◽  
High Deposition Rate ◽  
Layer By Layer ◽  
Microcrystalline Silicon

AbstractDue to the high temperatures used for high deposition rate microcrystalline (μc-Si:H) and polycrystalline silicon, there is a need for compact and temperature-stable doped layers. In this study we report on films grown by the layer-by-layer method (LbL) using VHF PECVD. Growth of an amorphous silicon layer is alternated by a hydrogen plasma treatment. In LbL, the surface reactions are separated time-wise from the nucleation in the bulk. We observed that it is possible to incorporate dopant atoms in the layer, without disturbing the nucleation. Even at high substrate temperatures (up to 400°C) doped layers can be made microcrystalline. At these temperatures, in the continuous wave case, crystallinity is hindered, which is generally attributed to the out-diffusion of hydrogen from the surface and the presence of impurities (dopants).We observe that the parameter window for the treatment time for p-layers is smaller compared to n-layers. Moreover we observe that for high temperatures, the nucleation of p-layers is more adversely affected than for n-layers. Thin, doped layers have been structurally, optically and electrically characterized. The best n-layer made at 400°C, with a thickness of only 31 nm, had an activation energy of 0.056 eV and a dark conductivity of 2.7 S/cm, while the best p-layer made at 350°C, with a thickness of 29 nm, had an activation energy of 0.11 V and a dark conductivity of 0.1 S/cm. The suitability of these high temperature n-layers has been demonstrated in an n-i-p microcrystalline silicon solar cell with an unoptimized μc-Si:H i-layer deposited at 250°C and without buffer. The Voc of the cell is 0.48 V and the fill factor is 70 %.

Sign in / Sign up

Export Citation Format

Share Document