scholarly journals THE SIZE AND SHAPE OF METAMORPHOSING LARVAE OF VENUS (MERCENARIA) MERCENARIA GROWN AT DIFFERENT TEMPERATURES

1959 ◽  
Vol 117 (2) ◽  
pp. 308-318 ◽  
Author(s):  
VICTOR L. LOOSANOFF
Keyword(s):  
Mercenaria Mercenaria ◽  
Size And Shape ◽  
Different Temperatures

scholarly journals STUDYING THE INFLUENCE OF THE TEMPERATURE ON MORPHOLOGY OF CONGLOMERATES FROM COPPER NANOPARTICLES OBTAINED BY ELECTROEROSION DISPERSION

2021 ◽  
Vol 1 (67) ◽  
pp. 38-42
Author(s):  
E. Klikin ◽  
N. Kuvardin ◽  
R. Lavrov
Keyword(s):  
Petroleum Ether ◽  
Copper Nanoparticles ◽  
Visual Observation ◽  
Temperature Factor ◽  
Liquid Media ◽  
Starch Solution ◽  
Size And Shape ◽  
Digital Microscope ◽  
Different Temperatures ◽  
Electroerosion Dispersion

Aim. To obtain conglomerates from copper nanoparticles by the method of electroerosive dispersion in various liquid media (in 1% starch solution, ethanol, acetone, kerosene, petroleum ether) at two different temperatures (negative and room). Assessment of the influence of this factor on the size and shape of the resulting conglomerates. Methods. Methods based on visual observation of the obtained particles using a digital microscope at a magnification of 600x. Results. The results are presented in the form of micrographs of the obtained particles. Conclusions. Conclusions are drawn on the study of the influence of the temperature factor on the morphology (size, shape and ordering) of the resulting conglomerates.

Crystallite size and shape in Twaron fibers heat treated at different temperatures using WAXS

2006 ◽  
Vol 100 (6) ◽  
pp. 4910-4916 ◽  
Author(s):  
Anjana Jain ◽  
S. Abhishek ◽  
Sangappa ◽  
S. S. Mahesh ◽  
R. Somashekar
Keyword(s):  
Crystallite Size ◽  
Size And Shape ◽  
Heat Treated ◽  
Different Temperatures

A Comparison of the Size and Shape of Radiofrequency Lesions Produced by Different Temperatures Using Straight and Curved Electrodes

2000 ◽  
Vol 39 (2) ◽  
pp. 260 ◽  
Author(s):  
Kee Heon Lee ◽  
Seon Hye Yun ◽  
Hyun Ju Kim ◽  
Bae Hee Jung ◽  
So Young Lim ◽  
...  
Keyword(s):  
Size And Shape ◽  
Different Temperatures ◽  
Radiofrequency Lesions

Some Aspects of the Growth of Single and Mixed Populations of Flagellates and Ciliates

1956 ◽  
Vol 33 (4) ◽  
pp. 627-644
Author(s):  
SMILJA MUČIBABIĆ
Keyword(s):  
Population Growth ◽  
Maximum Yield ◽  
Maximum Size ◽  
Multiplication Rate ◽  
Size And Shape ◽  
Different Temperatures ◽  
Temperature Ranges ◽  
Lower Temperature Range ◽  
Lower Temperature ◽  
The Relationship

Populations of Chilomonas paramecium have been maintained in a standard concentration of nutrient medium (0.1% beef-extract with 0.1% sodium acetate), at eight different temperatures, from 5 to 36° C. The temperatures 5 and 36° C. did not support the growth of a population. The rate of population growth increased with increase of temperature up to a maximum, and then decreased. The maximum yield, on the other hand, was not affected, within wide limits, by different temperatures. The relationship between temperature and maximum size of population was different when maximum size was expressed in total number of organisms from that when maximum size was expressed in terms of total volume of organisms. In the former case, the maximum size increased with the increase of temperature; while in the latter it decreased with increase of temperature. Bělehrádek's temperature coefficient, b, of the multiplication rate of Chilomonas did not show significant differences for different temperature ranges, while the coefficients Q10, and the thermal increment µ were larger for the lower temperature range. The size and shape of Chilomonas were found to depend on the temperature and on the age of the population. With increase in temperature, the size of organisms decreased to a minimum and then increased again, so that organisms were largest at extreme temperatures. In general, the organisms were more slender at lower than at higher temperatures. At all temperatures, the flagellate increased in size at the beginning of population growth and later decreased. Variation in size and shape was greatest at the beginning of growth and during transition to the maximum stationary phase.

Observations oh Nucleation and Growth of Voids in Nickel

1970 ◽  
Vol 28 ◽  
pp. 414-415
Author(s):  
J. L. Brimhall ◽  
H. E. Kissinger ◽  
B. Mastel
Keyword(s):  
High Purity ◽  
Growth Stage ◽  
Elevated Temperatures ◽  
Early Growth ◽  
Nucleation And Growth ◽  
Pure Nickel ◽  
Different Temperatures ◽  
Total Fluence ◽  
Neutron Exposure ◽  
Growth Of Voids

Some information on the size and density of voids that develop in several high purity metals and alloys during irradiation with neutrons at elevated temperatures has been reported as a function of irradiation parameters. An area of particular interest is the nucleation and early growth stage of voids. It is the purpose of this paper to describe the microstructure in high purity nickel after irradiation to a very low but constant neutron exposure at three different temperatures.Annealed specimens of 99-997% pure nickel in the form of foils 75μ thick were irradiated in a capsule to a total fluence of 2.2 × 1019 n/cm2 (E > 1.0 MeV). The capsule consisted of three temperature zones maintained by heaters and monitored by thermocouples at 350, 400, and 450°C, respectively. The temperature was automatically dropped to 60°C while the reactor was down.

Unbiased estimation of particle number and sizes using the new stereological tools: the disector, the fractionator, the selector, and the nucleator — or just point-sampled intercepts

1988 ◽  
Vol 46 ◽  
pp. 428-429
Author(s):  
H.J.G. Gundersen
Keyword(s):  
Particle Number ◽  
Small Distance ◽  
Parallel Plane ◽  
Unbiased Estimation ◽  
Severe Problem ◽  
New Era ◽  
Size And Shape ◽  
Distinct Property ◽  
Sectioned Tissue

Previously, all stereological estimation of particle number and sizes were based on models and notoriously gave biased results, were very inefficient to use and difficult to justify. For all references to old methods and a direct comparison with unbiased methods see recent reviews.The publication in 1984 of the DISECTOR, the first unbiased stereological probe for sampling and counting 3—D objects irrespective of their size and shape, signalled the new era in stereology — and give rise to a number of remarkably simple and efficient techniques based on its distinct property: It is the only known way to obtain an unbiased sample of 3-D objects (cells, organelles, etc). The principle is simple: within a 2-D unbiased frame count or sample only cells which are not hit by a parallel plane at a known, small distance h.The area of the frame and h must be known, which might sometimes in itself be a problem, albeit usually a small one. A more severe problem may arise because these constants are known at the scale of the fixed, embedded and sectioned tissue which is often shrunken considerably.

The structure of membranes and membrane proteins embedded in amorphous ice

1992 ◽  
Vol 50 (1) ◽  
pp. 432-433
Author(s):  
Uwe Lücken ◽  
Joachim Jäger
Keyword(s):  
Phase Transition ◽  
Transition Temperature ◽  
Membrane Proteins ◽  
Phase Transition Temperature ◽  
Lipid Vesicles ◽  
Freezing Stress ◽  
Amorphous Ice ◽  
Different Temperatures ◽  
Band Pass ◽  
Lipid Polymorphism

TEM imaging of frozen-hydrated lipid vesicles has been done by several groups Thermotrophic and lyotrophic polymorphism has been reported. By using image processing, computer simulation and tilt experiments, we tried to learn about the influence of freezing-stress and defocus artifacts on the lipid polymorphism and fine structure of the bilayer profile. We show integrated membrane proteins do modulate the bilayer structure and the morphology of the vesicles.Phase transitions of DMPC vesicles were visualized after freezing under equilibrium conditions at different temperatures in a controlled-environment vitrification system. Below the main phase transition temperature of 24°C (Fig. 1), vesicles show a facetted appearance due to the quasicrystalline areas. A gradual increase in temperature leads to melting processes with different morphology in the bilayer profile. Far above the phase transition temperature the bilayer profile is still present. In the band-pass-filtered images (Fig. 2) no significant change in the width of the bilayer profile is visible.

The influence of confocal microscope design on imaging performance

1993 ◽  
Vol 51 ◽  
pp. 144-145
Author(s):  
C J R Sheppard
Keyword(s):  
Image Quality ◽  
Fluorescence Imaging ◽  
Confocal Microscope ◽  
Industrial Applications ◽  
Three Dimensions ◽  
Design Parameters ◽  
Weak Signals ◽  
Size And Shape ◽  
Imaging Performance ◽  
Fundamental Limitation

The confocal microscope is now widely used in both biomedical and industrial applications for imaging, in three dimensions, objects with appreciable depth. There are now a range of different microscopes on the market, which have adopted a variety of different designs. The aim of this paper is to explore the effects on imaging performance of design parameters including the method of scanning, the type of detector, and the size and shape of the confocal aperture.It is becoming apparent that there is no such thing as an ideal confocal microscope: all systems have limitations and the best compromise depends on what the microscope is used for and how it is used. The most important compromise at present is between image quality and speed of scanning, which is particularly apparent when imaging with very weak signals. If great speed is not of importance, then the fundamental limitation for fluorescence imaging is the detection of sufficient numbers of photons before the fluorochrome bleaches.

Microstructure of sputter deposited Ni-Sb ohmic contacts on GaAs

1989 ◽  
Vol 47 ◽  
pp. 450-451
Author(s):  
S. Yegnasubramanian ◽  
V.C. Kannan ◽  
R. Dutto ◽  
P.J. Sakach
Keyword(s):  
High Performance ◽  
Ohmic Contacts ◽  
Surface Defects ◽  
Pure Metal ◽  
Device Fabrication ◽  
Native Oxide ◽  
Metal Thin Films ◽  
Recent Developments ◽  
Different Temperatures ◽  
Sputter Deposited

Recent developments in the fabrication of high performance GaAs devices impose crucial requirements of low resistance ohmic contacts with excellent contact properties such as, thermal stability, contact resistivity, contact depth, Schottky barrier height etc. The nature of the interface plays an important role in the stability of the contacts due to problems associated with interdiffusion and compound formation at the interface during device fabrication. Contacts of pure metal thin films on GaAs are not desirable due to the presence of the native oxide and surface defects at the interface. Nickel has been used as a contact metal on GaAs and has been found to be reactive at low temperatures. Formation Of Ni2 GaAs at 200 - 350C is reported and is found to grow epitaxially on (001) and on (111) GaAs, but is shown to be unstable at 450C. This paper reports the investigations carried out to understand the microstructure, nature of the interface and composition of sputter deposited and annealed (at different temperatures) Ni-Sb ohmic contacts on GaAs by TEM. Attempts were made to correlate the electrical properties of the films such as the sheet resistance and contact resistance, with the microstructure. The observations are corroborated by Scanning Auger Microprobe (SAM) investigations.

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