Selection of sample dipping time in liquid nitrogen prior to cryorolling for Al 1100 alloy

2017 ◽  
Author(s):  
Siti Aminah Zakaria ◽  
Zuhailawati Hussain ◽  
Anasyida Abu Seman
1980 ◽  
Vol 17 (2) ◽  
pp. 226-233 ◽  
Author(s):  
J. Y. S. Lee ◽  
P. B. Little

Lesions of cerebrocortical necrosis experimentally induced in pigs by transcalvarial freezing with liquid nitrogen were slightly fluorescent 48 hours after surgery. Fluorescence increased greatly thereafter and was most marked grossly under ultraviolet illumination with a wavelength of 366 nm at 7 days. Fluorescence of the necrotic focus persisted up to 35 days after surgery. Detection of cerebrocortical necrosis by ultraviolet illumination of fresh specimens during gross inspection is useful in determining the extent and distribution of lesions. This would aid more accurate selection of brain sections for histological examination in various encephalopathies.


Author(s):  
A. Gulov ◽  
A. Laskin

Purpose: Conducting a honey diluent test for creeples of sperm of a drone honey bee.Materials and methods. The material for the research served a sperm of the milled drone drums of the "Prioksky" type of the Midway breed of bees. The selection of sperm was carried out in June-July 2020 g by the method of artificial stimulation of the turning of the endofalosha in half-armed drones aged 25-30 days. The rock type "Prioksky" of the middle Russian breed of bees. Before freezing, the sperm was stored in glass capillaries in the cooled state at 3 ° C for 2 months. The following composition of the diluent was tested - 10% honey, lactose, sucrose, egg yolk and dimethyl sulfoxide.Results. Studies have shown the viability of sperm at 64.0 ± 1.8% (41.5-83.7), and a total mobility of 2.2 ± 0.6% (0-11.5). To evaluate the fertilizing ability of sperm, carried out artificial insemination of 10 bee modules. In 4 seeded bees dykens, the presence of sperm in a seed-hearter with a concentration of sperm from 0.22-4.4 million / μl is revealed. In paired eggs of three other seeded matters, the presence of sperm and the complete absence of spermatozoa in the seed-receptionist are recorded.Conclusion. Tests of the honey diluent for deep freezing sperm of the drone honey bees in liquid nitrogen confirmed its cryophylactic properties.


2017 ◽  
Vol 888 ◽  
pp. 409-412 ◽  
Author(s):  
Syarifah M. Noraini Sayed Ahmad ◽  
Zuhailawati Hussain ◽  
Anasyida Abu Seman

Cryorolling is indeed a very suitable approach in producing a good Al alloy of Al 5083 with exceptionally strong and hard properties. This new Severe Plastic Deformation (SPD) methods can bring out the utmost of strength in Al alloy compare with cold rolling. This paper hence discussed the effect of dipping duration of Al alloy in liquid nitrogen prior to rolling process to its improved mechanical properties such as hardness and tensile strength. The result showed that the hardness increased with increasing dipping time until 60 minutes for low temperature pre-anneal and 30 minutes for high temperature pre-anneal and later dropped. The tensile strength of cryorolled sample also showed some improvement for about 5-8% compared with normal cold rolling.


2019 ◽  
Vol 42 ◽  
Author(s):  
Gian Domenico Iannetti ◽  
Giorgio Vallortigara

Abstract Some of the foundations of Heyes’ radical reasoning seem to be based on a fractional selection of available evidence. Using an ethological perspective, we argue against Heyes’ rapid dismissal of innate cognitive instincts. Heyes’ use of fMRI studies of literacy to claim that culture assembles pieces of mental technology seems an example of incorrect reverse inferences and overlap theories pervasive in cognitive neuroscience.


1975 ◽  
Vol 26 ◽  
pp. 395-407
Author(s):  
S. Henriksen

The first question to be answered, in seeking coordinate systems for geodynamics, is: what is geodynamics? The answer is, of course, that geodynamics is that part of geophysics which is concerned with movements of the Earth, as opposed to geostatics which is the physics of the stationary Earth. But as far as we know, there is no stationary Earth – epur sic monere. So geodynamics is actually coextensive with geophysics, and coordinate systems suitable for the one should be suitable for the other. At the present time, there are not many coordinate systems, if any, that can be identified with a static Earth. Certainly the only coordinate of aeronomic (atmospheric) interest is the height, and this is usually either as geodynamic height or as pressure. In oceanology, the most important coordinate is depth, and this, like heights in the atmosphere, is expressed as metric depth from mean sea level, as geodynamic depth, or as pressure. Only for the earth do we find “static” systems in use, ana even here there is real question as to whether the systems are dynamic or static. So it would seem that our answer to the question, of what kind, of coordinate systems are we seeking, must be that we are looking for the same systems as are used in geophysics, and these systems are dynamic in nature already – that is, their definition involvestime.


1978 ◽  
Vol 48 ◽  
pp. 515-521
Author(s):  
W. Nicholson

SummaryA routine has been developed for the processing of the 5820 plates of the survey. The plates are measured on the automatic measuring machine, GALAXY, and the measures are subsequently processed by computer, to edit and then refer them to the SAO catalogue. A start has been made on measuring the plates, but the final selection of stars to be made is still a matter for discussion.


Author(s):  
Claude Lechene

Electron probe microanalysis of frozen hydrated kidneysThe goal of the method is to measure on the same preparation the chemical elemental content of the renal luminal tubular fluid and of the surrounding renal tubular cells. The following method has been developed. Rat kidneys are quenched in solid nitrogen. They are trimmed under liquid nitrogen and mounted in a copper holder using a conductive medium. Under liquid nitrogen, a flat surface is exposed by sawing with a diamond saw blade at constant speed and constant pressure using a custom-built cryosaw. Transfer into the electron probe column (Cameca, MBX) is made using a simple transfer device maintaining the sample under liquid nitrogen in an interlock chamber mounted on the electron probe column. After the liquid nitrogen is evaporated by creating a vacuum, the sample is pushed into the special stage of the instrument. The sample is maintained at close to liquid nitrogen temperature by circulation of liquid nitrogen in the special stage.


Author(s):  
Louis T. Germinario

A liquid nitrogen stage has been developed for the JEOL JEM-100B electron microscope equipped with a scanning attachment. The design is a modification of the standard JEM-100B SEM specimen holder with specimen cooling to any temperatures In the range ~ 55°K to room temperature. Since the specimen plane is maintained at the ‘high resolution’ focal position of the objective lens and ‘bumping’ and thermal drift la minimized by supercooling the liquid nitrogen, the high resolution capability of the microscope is maintained (Fig.4).


Author(s):  
O. T. Inal ◽  
L. E. Murr

When sharp metal filaments of W, Fe, Nb or Ta are observed in the field-ion microscope (FIM), their appearance is differentiated primarily by variations in regional brightness. This regional brightness, particularly prominent at liquid nitrogen temperature has been attributed in the main to chemical specificity which manifests itself in a paricular array of surface-atom electron-orbital configurations.Recently, anomalous image brightness and streaks in both fcc and bee materials observed in the FIM have been shown to be the result of surface asperities and related topographic features which arise by the unsystematic etching of the emission-tip end forms.


Author(s):  
P.J. Killingworth ◽  
M. Warren

Ultimate resolution in the scanning electron microscope is determined not only by the diameter of the incident electron beam, but by interaction of that beam with the specimen material. Generally, while minimum beam diameter diminishes with increasing voltage, due to the reduced effect of aberration component and magnetic interference, the excited volume within the sample increases with electron energy. Thus, for any given material and imaging signal, there is an optimum volt age to achieve best resolution.In the case of organic materials, which are in general of low density and electric ally non-conducting; and may in addition be susceptible to radiation and heat damage, the selection of correct operating parameters is extremely critical and is achiev ed by interative adjustment.


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