scholarly journals Ensuring a Stable Relative Area of Burnishing of Partially Regular Microrelief Formed on End Surfaces of Rotary Bodies

2021 ◽  
Vol 71 (1) ◽  
pp. 41-50
Author(s):  
Dzyura Volodymyr ◽  
Maruschak Pavlo ◽  
Tkachenko Ihor ◽  
Kuchvara Ivan
Keyword(s):  
Geometric Parameters ◽  
Analytical Dependence ◽  
Type Ii ◽  
Relative Area ◽  
Center Of Rotation

Abstract The scheme of arrangement of grooves of partially regular microrelief of type II shifted by 0.5 angular pitch is considered. Such grooves are formed by vibration on end faces of rotary bodies. An analytical dependence was obtained to determine the relative area of a partially regular microrelief depending on the geometric parameters of V-shaped grooves. The parameters of the grooves of a partially regular microrelief formed at different distances from the center of rotation are determined, at which the value of the relative area of the partially regular microrelief formed on the treated surface will be stable.

scholarly journals Determining Optimal Parameters of Regular Microrelief Formed on the End Surfaces of Rotary Bodies

Algorithms ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 46
Author(s):  
Volodymyr Dzyura ◽  
Pavlo Maruschak ◽  
Olegas Prentkovskis
Keyword(s):  
Block Diagram ◽  
Geometric Parameters ◽  
Geometrical Parameters ◽  
Optimal Parameters ◽  
Center Of Rotation ◽  
Optimal Value ◽  
Different Types ◽  
The Relationship ◽  
Overlap Area

The analytical dependences for determining the overlap area of V-shaped grooves of partially regular microrelief shifted by an angular pitch of 0.5° are established. The V-shaped grooves are formed on the end surface of the rotary body by vibration. In addition, the intersection between groove elements can be of different types. The relationship between the geometric parameters of V-shaped grooves and their location is determined. The influence of geometrical parameters of grooves on the overlap area is established depending on their location. Measures are proposed to ensure that the burnishing area is the same at different distances from the center of rotation of the rotary body end surface on which the partially regular microrelief is formed. A graph showing the dependence of the overlap area of two grooves on the axial pitch between them is constructed, and a block diagram of the algorithm for determining the optimal value of the axial pitch is developed.

scholarly journals Pressure Fluctuations Characteristics of the Stilling Basin with a Negative Step

2021 ◽  
Author(s):  
Guibing Huang ◽  
Mingjun Diao ◽  
Lei Jiang ◽  
Chuan’ai Wang ◽  
Wang Jia
Keyword(s):  
Incident Angle ◽  
Pressure Coefficient ◽  
Pressure Fluctuations ◽  
Jet Impingement ◽  
Dominant Frequency ◽  
Geometric Parameters ◽  
Step Height ◽  
Type Ii ◽  
Fluctuating Pressure ◽  
Stilling Basin

Fluctuating pressure is the main cause of the floor fatigue of the stilling basin with a negative step. Despite investigations of stilling basin with a negative step conducted by many researchers, there is not enough information about the influence of the geometric parameters on fluctuating pressure on the floor. In the present study, fluctuating pressure on the floor of the stilling basin with a negative step was systematically investigated by a total of 85 model tests. The results show that the fluctuating pressure coefficient Cp’ has a process of rapid increase and decrease, and then decreases slowly until it becomes stable, and the maximum fluctuating pressure coefficient Cp’max lies in the reattachment zone rather than in the jet impingement area for Type II-jump. The dominant frequency of the fluctuating pressure on the floor shows a decreasing trend along stilling basin. With the increase of the step height, the Cp’max presents decreasing trend but X*0 where the Cp’max occurs increasing trend. While there has on obvious regularity between incident angle and Cp’. Finally, according to the fitting of test data, an empirical formula to calculate Cp’max is developed. These research results provide reference for the design of stilling basin with a negative step in engineering applications.

scholarly journals Parameters of tillage working bodies

2021 ◽  
Vol 284 ◽  
pp. 02012
Author(s):  
Abdulhay Obidov ◽  
Karimjon Nuriev ◽  
Madrahim Allanazarov ◽  
Ermamat Kurbonov ◽  
Rustam Khudoyberdiev
Keyword(s):  
Geometric Parameters ◽  
Analytical Dependence ◽  
Limiting State ◽  
Soil Cutting ◽  
Working Bodies

This article notes that most of the soil-cutting working bodies wear out their socks a lot, as a result of which their limiting state is reached. Despite the fact that other parts of the working body are still workable and the stock of metal for wear is still sufficient, the working body is completely rejected. In this regard, it is emphasized that increasing the durability of the nose parts leads to an increase in the durability of the entire working body. To determine its parameters, the condition for leveling the resources of socks and other parts of the soil-cutting working bodies is considered. When determining the length of the nose of the bits, an analytical dependence is recommended, taking into account the geometric parameters of the bit and the plowshares welded to it. To obtain self-sharpening in the process of bit nose wear, it is recommended to use a new two-faceted profile. The rational values of the length, the angle of the wedge and the sharpening of the nose are determined, equal to 90 mm, 100 and 350-400, respectively. Based on the condition of rational combinations of strength and self-sharpening characteristics of the toes of bits, the thickness and width of the latter were determined, equal to 22.3 mm and 30 mm, respectively.

GRAVITATIONAL COLLAPSE OF HOMOGENEOUS SPHEROIDS

2010 ◽  
Vol 19 (08n10) ◽  
pp. 1335-1338
Author(s):  
H. RODRIGUES ◽  
D. PORTES ◽  
S. B. DUARTE
Keyword(s):  
Time Evolution ◽  
Gravitational Collapse ◽  
Final Stage ◽  
Geometric Parameters ◽  
Lagrangian Description ◽  
Type Ii ◽  
The Core ◽  
Effective Lagrangian ◽  
Homogeneous Spheroid ◽  
Protoneutron Star

We present a simplified description of the gravitational collapse of a uniformly rotating neutron stellar core, which can represent the final stage of the protoneutron star formed after the supernova type II explosion. The system is treated as a compressible homogeneous spheroid and the collapse time-evolution is extracted from an effective Lagrangian description of the system geometric parameters. A sudden mass quadripole change of the system at the final stage of the collapse is shown during the core bounce.

Type II Solar Radio Bursts over Solar Cycle 21

1994 ◽  
Vol 144 ◽  
pp. 283-284
Author(s):  
G. Maris ◽  
E. Tifrea
Keyword(s):  
Solar Radio ◽  
Interplanetary Space ◽  
Impulsive Phase ◽  
Radio Bursts ◽  
Type Ii ◽  
Solar Radio Bursts ◽  
Strong Energy ◽  
Mass Ejection ◽  
Geophysical Effect ◽  
Radio Event

The type II solar radio bursts produced by a shock wave passing through the solar corona are one of the most frequently studied solar activity phenomena. The scientific interest in this type of phenomenon is due to the fact that the presence of this radio event in a solar flare is an almost certain indicator of a future geophysical effect. The origin of the shock waves which produce these bursts is not at all simple; besides the shocks which are generated as a result of a strong energy release during the impulsive phase of a flare, there are also the shocks generated by a coronal mass ejection or the shocks which appear in the interplanetary space due to the supplementary acceleration of the solar particles.

Heat-Etching with a Bullivant Type II Simple Freeze-Cleave Device

1970 ◽  
Vol 28 ◽  
pp. 106-107 ◽  
Author(s):  
Ronald S. Weinstein ◽  
N. Scott McNutt
Keyword(s):  
New Zealand ◽  
General Hospital ◽  
Massachusetts General Hospital ◽  
Type I ◽  
Type Ii ◽  
Collaborative Effort ◽  
Temperature And Pressure ◽  
The University

The Type I simple cold block device was described by Bullivant and Ames in 1966 and represented the product of the first successful effort to simplify the equipment required to do sophisticated freeze-cleave techniques. Bullivant, Weinstein and Someda described the Type II device which is a modification of the Type I device and was developed as a collaborative effort at the Massachusetts General Hospital and the University of Auckland, New Zealand. The modifications reduced specimen contamination and provided controlled specimen warming for heat-etching of fracture faces. We have now tested the Mass. General Hospital version of the Type II device (called the “Type II-MGH device”) on a wide variety of biological specimens and have established temperature and pressure curves for routine heat-etching with the device.

Ultrastructure of pulmonary microvasculature in acute endotoxemia

1978 ◽  
Vol 36 (2) ◽  
pp. 470-471
Author(s):  
R. G. Gerrity ◽  
M. Richardson
Keyword(s):  
Polymorphonuclear Leukocytes ◽  
Alveolar Epithelium ◽  
Endothelial Damage ◽  
Capillary Endothelium ◽  
Type Ii Cells ◽  
Type Ii ◽  
Interstitial Edema ◽  
Pulmonary Capillaries ◽  
Lung Ultrastructure ◽  
Fibrin Thrombi

Dogs were injected intravenously with E_. coli endotoxin (2 mg/kg), and lung samples were taken at 15 min., 1 hr. and 24 hrs. At 15 min., occlusion of pulmonary capillaries by degranulating platelets and polymorphonuclear leukocytes (PML) was evident (Fig. 1). Capillary endothelium was intact but endothelial damage in small arteries and arterioles, accompanied by intraalveolar hemorrhage, was frequent (Fig. 2). Sloughing of the surfactant layer from alveolar epithelium was evident (Fig. 1). At 1 hr., platelet-PML plugs were no longer seen in capillaries, the endothelium of which was often vacuolated (Fig. 3). Interstitial edema and destruction of alveolar epithelium were seen, and type II cells had discharged their granules into the alveoli (Fig. 4). At 24 hr. phagocytic PML's were frequent in peripheral alveoli, while centrally, alveoli and vessels were packed with fibrin thrombi and PML's (Fig. 5). In similar dogs rendered thrombocytopenic with anti-platelet serum, lung ultrastructure was similar to that of controls, although PML's were more frequently seen in capillaries in the former (Fig. 6).

Mitochondria microcrystals deposition in some inherited diseases of lipid metabolism.

1978 ◽  
Vol 36 (2) ◽  
pp. 256-257
Author(s):  
S. Laoussadi ◽  
A. Kahan ◽  
G. Aubouy ◽  
F. Delbarre
Keyword(s):  
Synovial Tissue ◽  
Storage Disease ◽  
Metabolic Diseases ◽  
Uranyl Acetate ◽  
List Type ◽  
Type Ii ◽  
Type Number ◽  
Lipid Storage Disease ◽  
Thin Sections ◽  
Mean Size

Several patients with Fabry's, Gaucher's diseases and hyperlipoproteinemia type II and with arthropatic manifestations were observed.As no histological explanation for these symptoms was available,an ultrastructural study of synovial tissue was done to establish an anatomoclinical relation.Material and Methods :synovial membrane samples were obtained by needle biopsies of the knee from three patients with arthropatic manifestations of each disease.They were fixed in 5% glutaraldehyde, postfixed in 1% osmium tetraoxyde and embedded in Epon 812. Thin sections coloured by uranyl acetate and lead citrate were observed with an Elmiskop I Siemens electron microscope.Two important phenomena were observed in synovial tissue:Specific patterns of each lipid storage disease,which are now well known.In all the three metabolic diseases, hydroxyapatite-like crystals were found. They are characterized by their intramitochondrial localization, without any relation with cristae,an anarchic disposition and a mean size of 550 A.Crystals may be found also free in the cytoplasm of synoviocytes Some micrographs suggest an evolution in four steps :a. mitochondria with only a few microcrystalsb. mitochondria stuffed with these structuresc. disruption of mitochondria membranesd. microcrystals appear free in the cytoplasm

Labelling of non-A, non-B hepatitis infected chimpanzee hepatocytes with nuclease-gold conjugates

1984 ◽  
Vol 42 ◽  
pp. 250-251
Author(s):  
G. D. Gagne ◽  
M. F. Miller ◽  
D. A. Peterson
Keyword(s):  
Endoplasmic Reticulum ◽  
Experimental Infection ◽  
Uranyl Acetate ◽  
Type I ◽  
Cellular Injury ◽  
Type Ii ◽  
Tubular Structures ◽  
Type Iii ◽  
Type Iv ◽  
Infected Chimpanzee

Experimental infection of chimpanzees with non-A, non-B hepatitis (NANB) or with delta agent hepatitis results in the appearance of characteristic cytoplasmic alterations in the hepatocytes. These alterations include spongelike inclusions (Type I), attached convoluted membranes (Type II), tubular structures (Type III), and microtubular aggregates (Type IV) (Fig. 1). Type I, II and III structures are, by association, believed to be derived from endoplasmic reticulum and may be morphogenetically related. Type IV structures are generally observed free in the cytoplasm but sometimes in the vicinity of type III structures. It is not known whether these structures are somehow involved in the replication and/or assembly of the putative NANB virus or whether they are simply nonspecific responses to cellular injury. When treated with uranyl acetate, type I, II and III structures stain intensely as if they might contain nucleic acids. If these structures do correspond to intermediates in the replication of a virus, one might expect them to contain DNA or RNA and the present study was undertaken to explore this possibility.

Interfacial studies in Nb3Sn superconductors

1991 ◽  
Vol 49 ◽  
pp. 590-591
Author(s):  
Ernest L. Hall ◽  
Lee E. Rumaner ◽  
Mark G. Benz
Keyword(s):  
Grain Size ◽  
Grain Boundaries ◽  
Flux Pinning ◽  
Size Control ◽  
High Magnetic Fields ◽  
Type Ii ◽  
Reaction Interface ◽  
Liquid Diffusion ◽  
Type Ii Superconductor ◽  
Grain Size Control

The intermetallic compound Nb3Sn is a type-II superconductor of interest because it has high values of critical current density Jc in high magnetic fields. One method of forming this compound involves diffusion of Sn into Nb foil containing small amounts of Zr and O. In order to maintain high values of Jc, it is important to keep the grain size in the Nb3Sn as small as possible, since the grain boundaries act as flux-pinning sites. It has been known for many years that Zr and O were essential to grain size control in this process. In previous work, we have shown that (a) the Sn is transported to the Nb3Sn/Nb interface by liquid diffusion along grain boundaries; (b) the Zr and O form small ZrO2 particles in the Nb3Sn grains; and (c) many very small Nb3Sn grains nucleate from a single Nb grain at the reaction interface. In this paper we report the results of detailed studies of the Nb3Sn/Nb3Sn, Nb3Sn/Nb, and Nb3Sn/ZrO2 interfaces.

Sign in / Sign up

Export Citation Format

Share Document