FORMATION OF ICE MICROPARTICLES IN THE HOMOGENATE OF NATIVE EGGS OF STURGEON FISH DURING CRYOPRESERVATION

2020 ◽  
Author(s):  
A.V. Firsova ◽  
Keyword(s):  
Chemical Composition ◽  
Thin Layer ◽  
Room Temperature ◽  
Freezing Temperature ◽  
Russian Sturgeon ◽  
Frozen Solution ◽  
Sturgeon Fish ◽  
Shape And Size

In this work, we studied the formation of ice microparticles in a thin layer (0.2 mm) of the protoplasm of Russian sturgeon caviar upon cooling to a temperature of -196 ° C. Upon gradual cooling from room temperature + 20 ° C to -196 ° C, the process of freezing, formation and changes of ice microparticles were observed. The shape and size of the particles depended on the composition of the frozen solution. The freezing temperature for all layers of protoplasm was different, which is due to the chemical composition.

FROM A COMPACT TO A RUGGED BORDER IN RAMIFIED COPPER ELECTRODEPOSITS

Fractals ◽  
1996 ◽  
Vol 04 (01) ◽  
pp. 7-16 ◽  
Author(s):  
D. OTERO ◽  
G. MARSHALL ◽  
S. TAGTACHIAN
Keyword(s):  
Electron Microscopy ◽  
Chemical Composition ◽  
Thin Layer ◽  
Relative Concentration ◽  
Building Blocks ◽  
Bragg Diffraction ◽  
X Rays ◽  
Main Interest ◽  
Well Differentiated ◽  
Shape And Size

We study the origin of the rugged border of thin-layer ramified copper electrodeposits influenced by chemical perturbations. Our main interest is to look for the smallest growth building blocks toward the understanding of the transition from a compact to a rugged structure. Using electron microscopy, we found two building blocks, well differentiated in shape and size, consisting of: (a) Spikes or rods of a diameter between 100 and 500 nm and a maximum observed length of up to 10 μm; and (b) crystalline grains with a diameter between 200 nm and 2 μm. Through X-rays Bragg diffraction, we tentatively assessed a Cu2O and metallic Cu chemical composition to the crystals and rods, respectively. The relative concentration of metallic Cu to Cu2O changes as we move from the base to the front of the aggregation and this result could be associated with the Hecker effect.

Applications of Photoelectron Microscopy

1976 ◽  
Vol 34 ◽  
pp. 506-507
Author(s):  
William J. Baxter
Keyword(s):  
Electron Microscopy ◽  
Thermal Decomposition ◽  
Chemical Composition ◽  
Ultraviolet Radiation ◽  
Thin Layer ◽  
Edge Effects ◽  
Electron Optics ◽  
Surface Layers ◽  
Crystalline Orientation ◽  
Fluorescent Screen

In this form of electron microscopy, photoelectrons emitted from a metal by ultraviolet radiation are accelerated and imaged onto a fluorescent screen by conventional electron optics. image contrast is determined by spatial variations in the intensity of the photoemission. The dominant source of contrast is due to changes in the photoelectric work function, between surfaces of different crystalline orientation, or different chemical composition. Topographical variations produce a relatively weak contrast due to shadowing and edge effects.Since the photoelectrons originate from the surface layers (e.g. ∼5-10 nm for metals), photoelectron microscopy is surface sensitive. Thus to see the microstructure of a metal the thin layer (∼3 nm) of surface oxide must be removed, either by ion bombardment or by thermal decomposition in the vacuum of the microscope.

Thermomechanical Treatment of a 4340 Ni-Cr-Mo Alloy Steel

1981 ◽  
Vol 39 ◽  
pp. 314-315 ◽  
Author(s):  
M.T. Jahn ◽  
J.C. Yang ◽  
C.M. Wan
Keyword(s):  
Mechanical Property ◽  
Chemical Composition ◽  
Alloy Steel ◽  
Thermomechanical Treatment ◽  
Room Temperature ◽  
Good Combination ◽  
Thermal Treatments ◽  
Low Carbon ◽  
4340 Steel ◽  
Good Improvement

4340 Ni-Cr-Mo alloy steel is widely used due to its good combination of strength and toughness. The mechanical property of 4340 steel can be improved by various thermal treatments. The influence of thermomechanical treatment (TMT) has been studied in a low carbon Ni-Cr-Mo steel having chemical composition closed to 4340 steel. TMT of 4340 steel is rarely examined up to now. In this study we obtain good improvement on the mechanical property of 4340 steel by TMT. The mechanism is explained in terms of TEM microstructures4340 (0.39C-1.81Ni-0.93Cr-0.26Mo) steel was austenitized at 950°C for 30 minutes. The TMTed specimen (T) was obtained by forging the specimen continuously as the temperature of the specimen was decreasing from 950°C to 600°C followed by oil quenching to room temperature. The thickness reduction ratio by forging is 40%. The conventional specimen (C) was obtained by quenching the specimen directly into room temperature oil after austenitized at 950°C for 30 minutes. All quenched specimens (T and C) were then tempered at 450, 500, 550, 600 or 650°C for four hours respectively.

Fracture Toughness of Large Forgings for Power Producing Industry

2013 ◽  
Vol 577-578 ◽  
pp. 593-596 ◽  
Author(s):  
Václav Mentl
Keyword(s):  
Fracture Toughness ◽  
Chemical Composition ◽  
Steam Turbine ◽  
Mechanical Treatment ◽  
Material Degradation ◽  
The Real ◽  
Operational Safety ◽  
Local Properties ◽  
Thermo Mechanical Treatment ◽  
Shape And Size

The steam turbine rotors represent large components both in radial and axial directions. Their local properties generally differ from one forging to another, or if we compare head and bottom parts of the original ingot, or central and circumferential localities of one rotor body respectively, or if we compare the properties of separate discs e.g. in the case of welded rotors. These differences stem from both even slight changes in the chemical composition (of separate heats or even within one ingot) and thermo-mechanical treatment and in the differences in technology with respect to the real shape and size of the forgings in question. In the paper, the consequences of the differences in fracture toughness characteristics in various rotor localities are discussed with respect to the rotors operational safety taking into account the existence of cracks and material degradation.

scholarly journals DATA ON THE DEVELOPMENT OF HETERAKIS PAPILLOSA IN THE FOWL

1921 ◽  
Vol 34 (3) ◽  
pp. 259-270 ◽  
Author(s):  
H. W. Graybill
Keyword(s):  
Small Intestine ◽  
Salt Solution ◽  
Final Stage ◽  
Minimum Temperature ◽  
Growth And Development ◽  
Room Temperature ◽  
Freezing Temperature ◽  
Physiological Salt Solution ◽  
Natural Conditions ◽  
Short Intervals

In observations on the development of the ova of Heterakis papillosa in cultures, it was found that they failed to develop at a temperature ranging from 2.5–8°C., but developed slowly at a temperature of 11.5–13.5°C. The minimum temperature for development seems to lie between 8° and 11.5–13.5°C. At temperatures ranging in various cultures from 18–29°C. ova developed to their final stage in 7 to 12 days. Undeveloped ova subjected to a freezing temperature for a period of 4 days were viable at the end of that time. Fully developed ones remained alive when exposed out of doors for a period of 7 days at a temperature ranging from 5–62°F. Undeveloped ova survived desiccation at room temperature for a period of 16 days, but not for 41 days. Fully developed eggs were alive after desiccation for 18 days, but not after 49 days. In another instance they were no longer viable after 10 days. Embryos within ova kept in physiological salt solution at room temperature survived during a period of a little over 12 months. Fully developed ova kept in soil outdoors under circumstances approaching natural conditions contained living embryos after a period of 8 months. From a study of a series of artificially infested chickens killed at short intervals it appears that the ova of Heterakis hatch in the small intestine and the larvæ pass by way of the small and large intestines to the ceca where they undergo development to maturity. Larvæ found in the mucosa of the ceca were not in an encysted condition. Feeding of numerous artificially incubated ova may lead to a light infestation, the cause of which has not been definitely determined. A period of 57 days was required for larvæ to reach maturity in a host. The entire cycle from egg to adult requires a minimum time of about 64 days. A brief study of the growth and development of larvæ within the host has been made. No evidence was found of a migration through the tissues. A few penetrate into the mucosa of the ceca.

scholarly journals THE EFFECT OF ABRASIVE GRAIN SHAPES ON QUALITY OF FERRITE MAGNETS GRINDING PROCESS

2020 ◽  
Vol 14 (2) ◽  
pp. 117-124
Author(s):  
Bayu Rahmat Saputro ◽  
Amin Suhadi
Keyword(s):  
Chemical Composition ◽  
Single Layer ◽  
Processing Parameters ◽  
Grinding Process ◽  
Model Design ◽  
Grinding Wheels ◽  
Abrasive Grains ◽  
Abrasive Grain ◽  
Shape And Size

Abstract A research was conducted on the grinding process of ferrite magnet with Strontium ferrite type (SrO.6 (Fe2O3)) using electroplated single layer grinding wheels. Many cracks have been found on work pieces during this work, which is coming from grinding processes. Research is conducted starting from chemical composition test and the effect of the shape and size of the abrasive grain of grinding wheels to the quality of grinding process results by measuring crack ratio of the work piece.  In this experiment, 3 (three) model design of grinding wheels with three different size and shape of abrasive grains are made. All of processing parameters are set at the same value as ordinary process.  The experimental results shown that 3rd model have the best results from the outputs number and also the lowest reject crack ratio compared to 1st and 2nd models. This is because the 3rd model has blocky shape which its distribution structure is denser and more uniform compared to the irregular shape, so that continuous grinding on hard and brittle work pieces is more stable and suitable

scholarly journals SINTESIS CALKON ((E)-1,3-DI(NAPHTHALEN-2-YL)PROP-2-EN-1-ONE) DAN AKTIVITASNYA SEBAGAI ANTIOKSIDAN

2012 ◽  
Vol 3 (1) ◽  
pp. 7-14
Author(s):  
Rahmiwati Hilma ◽  
Jasril ◽  
Hilwan Yuda Teruna
Keyword(s):  
Free Radical ◽  
Melting Point ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Room Temperature ◽  
Intermediate Compound ◽  
Alkaline Condition ◽  
Point Measurement ◽  
Anti Inflammatory ◽  
Layer Chromatography

Study on chalcone calkon (E)-1,3-di(naphthalen-2-yl)prop-2-en-1-one synthesis have been carried out with stirrer methode. These compounds can be used as intermediate compound to synthesize others compounds which was reported having antimicrobial, anti-inflammatory, anti-depressant, anti-tumour. The of chalcones synthesis vatives were reported in acid and alkali condition. In this study, chalcone and its derivates were synthesized by using stirrer method in alkaline condition in room temperature. the compounds subjected to somes analyses including melting point measurement, thin layer chromatography and HPLC. Scavenging free radical by using DPPH methode showed Scavenging free radical with LC50 >80 μg/ml min potent activity while the ascorbat acid LC50 89,79 μg/ml.

ROOM TEMPERATURE MAGNETIC ANOMALIES IN BENZENE TREATED Bi–Pb–Sr–Ca–Cu–O POWDER

1991 ◽  
Vol 05 (21) ◽  
pp. 1447-1456 ◽  
Author(s):  
A. R. HARUTUNYAN ◽  
L. S. GRIGORYAN ◽  
A. S. KUZANYAN ◽  
A. A. KUZNETSOV ◽  
A. A. TERENTIEV ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Chemical Composition ◽  
Room Temperature ◽  
Microprobe Analysis ◽  
Magnetic Anomalies ◽  
X Ray Diffraction ◽  
X Ray ◽  
Two Samples ◽  
Field Dependent ◽  
History Of

Two samples of benzene-treated Bi–Pb–Sr–Ca–Cu–O powder exhibited at 300 K magnetic field dependent diamagnetism and magnetization irreversibility. The treatment with benzene resulted also in the appearance of microwave absorption at low magnetic fields, while is sensitive to magnetic history of the sample. From X-ray diffraction data one can see that upon benzene treatment the reflections of 85 K and 110 K phases do not change practically, but a series of new reflections appeared, indicating a lattice modulation with 4.9 nm periodicity. A microprobe analysis revealed substantial inhomogeneity of chemical composition across the samples. The room temperature anomalies were weakened in one sample and vanished in the second upon thermal cycling.

Room-Temperature Photoreflectance Spectra Of Thin-Layer (<200A) InP Doping Superlattices

1989 ◽  
Author(s):  
P. Y. Hsieh ◽  
Z. Shi ◽  
J. C. Chen ◽  
P. L. Liu
Keyword(s):  
Thin Layer ◽  
Room Temperature

Some aspects of fishery development of sturgeon hybrids in Russia. Part 1

2021 ◽  
pp. 16-29
Author(s):  
Evgeny Alekseevich Melchenkov ◽  
Aleksey Vladimirovich Myshkin ◽  
Vera Veniaminovna Kalmykova ◽  
Aleksandr Pavlovich Vorob’yov ◽  
Arthur Alekseevich Archibasov
Keyword(s):  
Biological Characteristics ◽  
Russian Sturgeon ◽  
Fish Farms ◽  
Commercial Cultivation ◽  
Recirculating Aquaculture ◽  
Fish Breeding ◽  
Adaptive Capabilities ◽  
Cultivation Technique ◽  
Sturgeon Fish ◽  
Hybrid Forms

With the development of commercial sturgeon breeding, creating hybrid forms of sturgeon fish in order to obtain a larger volume of gourmet marketable products is of increasing interest to fish farmers. The choice of objects for creating hybrid forms for commercial cultivation depends on the conditions and biotechnologies of intensive fish culture. One of the widely used technologies that can several times reduce the time for growing objects and receive viable juveniles and marketable products year-round is the technology using recirculating aquaculture system (RAS). With this cultivation technique, the advantage is given to species with high adaptive capabilities and growth intensity. The most popular objects for hybridization and creation of hybrid forms are beluga, sterlet, Siberian and Russian sturgeon, etc. Beluga is the largest representative of the sturgeon family. It reaches commodity weight (3–5 kg) against the background of natural temperatures within 2–3 years. The Sterlet is a pure freshwater form. It is an excellent object for cross-breeding with other sturgeon species, in particular with beluga to obtain a bester hybrid. The Siberian sturgeon grows most intensively at a temperature of 15–25 °C, however, the growth persists at lower temperatures (1–10 °C). The Russian sturgeon in artificial conditions reaches a marketable weight of 1.5–3.0 kg in the second-third years of cultivation. In order to facilitate the orientation of fish farms, fish farmers engaged in the production of commercial products, the article discusses the creation of hybrid forms of sturgeon fish in domestic and foreign aquaculture, provides their brief fish-breeding and biological characteristics when grown in fish farms of various types. Knowledge of the fish-breeding and biological characteristics of sturgeon fish species hybrids when grown in specific conditions will make it possible to successfully introduce them into the practice of commercial cultivation.

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