IMPROVING THE PERFORMANCE OF LARGE-SIZED MACHINE PARTS IN MACHINE-BUILDING AND METALLURGICAL INDUSTRIES

2020 ◽  
Vol 4 (1) ◽  
pp. 49-51
Author(s):  
P.A. TSIRKOV ◽  
D.A. LEBEDEVA ◽  
A.V. BURYAKIN
Keyword(s):  
Machine Building ◽  
Machine Parts ◽  
High Degree

The present work is devoted a way to improve the performance of large-sized machine parts of machine-building and metallurgical industries that operating in difficult conditions and subject to a high degree of wear.

METHODS FOR RESTORING WOLVES OF ROLLING PRODUCTION

2020 ◽  
Vol 4 (141) ◽  
pp. 114-122
Author(s):  
DAR’YA LEBEDEVA ◽  
◽  
ANNA KARPUNICHEVA
Keyword(s):  
Thermal Effects ◽  
Machine Building ◽  
Research Purpose ◽  
Technical Literature ◽  
Production Methods ◽  
Advantages And Disadvantages ◽  
Rolling Production ◽  
Machine Parts ◽  
The Stability ◽  
High Degree

Large forces and significant thermal effects are created on the rolls when rolling sheets. The higher the stability of the rolls, the less downtime during their rerolling and higher productivity. (Research purpose) The research purpose is in analyzing the ways of restoring rolls and choose the most appropriate method for restoring these parts. (Materials and methods) The article presents the analysis of the scientific and technical literature on the topic of rolling production, methods for restoring large-sized machine parts of machine-building and metallurgical industries that work in difficult conditions and are subject to a high degree of wear. Authors try to solve the problem by means of comparative and logical analysis based on theoretical and empirical methods of scientific research. (Results and discussion) The article presents two groups of methods for restoring rolled rolls: banding and surfacing the working layer of the roll. Authors have analyzed each method in terms of technology, equipment, and feasibility. The article presents the advantages and disadvantages of the methods under consideration. (Conclusions) The most acceptable way to restore parts with a high degree of wear is surfacing. It is most efficient to apply submerged surfacing using an additional hot additive. Such surfacing, despite some complication of the equipment design, allows to deposit the metal on the roll with low heat input and in most cases in one pass. Surfacing using an additional hot additive allows to increase the productivity of the process by up to 250 percent while reducing the penetration depth by 2-3 times and saving energy by up to 40 percent.

AISI TYPE L6

Alloy Digest ◽  
1971 ◽  
Vol 20 (1) ◽  
Keyword(s):  
Wear Resistance ◽  
Compressive Strength ◽  
Tensile Properties ◽  
Tool Steel ◽  
Heat Treating ◽  
Steel Mills ◽  
Aisi Type ◽  
Machine Parts ◽  
High Degree

Abstract AISI Type L6 is recommended for tools, dies and machine parts which must develop a rather high degree of hardness, wear resistance and compressive strength combined with toughness. This datasheet provides information on composition, hardness, elasticity, and tensile properties. It also includes information on forming, heat treating, machining, and joining. Filing Code: TS-232. Producer or source: Tool steel mills.

Materials science in machine tool industry

2018 ◽  
Author(s):  
Анатолий Адаскин ◽  
Anatoliy Adaskin
Keyword(s):  
Machine Tool ◽  
Materials Science ◽  
Rolling Friction ◽  
Machine Building ◽  
Operating Conditions ◽  
Main Task ◽  
Processing Technologies ◽  
Machine Tool Industry ◽  
Design Engineers ◽  
Machine Parts

The textbook defines the main task of materials science in the machine tool industry-is the choice of materials and technologies that determine the accuracy of the machine. Structural materials for the manufacture of machine parts, materials of cutting, auxiliary tools and parts of devices are considered. These are the materials of parts of the system "machine-tool-tool-part" - AIDS system, which determines the rigidity of the machine and the accuracy of processing. Possible causes and mechanisms of loss of accuracy and efficiency of the machine are shown: wear and spontaneous change in the size of parts over time, fatigue failure. The principles and recommendations of the choice of materials of steel and cast iron metal – intensive parts and parts of the counter-bodies of sliding and rolling friction pairs, as well as reinforcing and stabilizing processing technologies that ensure the preservation of long-term accuracy of the machine are given. The Appendix contains recommendations on the selection of tool materials for different operating conditions of mills and tools; materials of friction pairs; routing technology for manufacturing precision machine parts. The textbook is intended for bachelors and masters studying in the specialties 15.00 "mechanical engineering", 22.00 "technology of materials" can be used in the training of graduate students of machine – building specialties and to improve the skills of design engineers and technologists of machine-building plants, primarily machine-tool enterprises.

scholarly journals Modeling of cable-stayed bridge and research of frequency characteristics

2021 ◽  
pp. 61-66
Author(s):  
Serhii Krasnikov
Keyword(s):  
Natural Frequencies ◽  
Emergency Situation ◽  
Machine Building ◽  
Frequency Characteristics ◽  
Emergency Situations ◽  
Building Models ◽  
Real Model ◽  
Building Systems ◽  
Different Types ◽  
High Degree

The frequency characteristics of the cablestayed bridge according to several of its schemes are considered. The analysis of the influence on the frequency characteristics of the type of resistance according to different sets is carried out. Among the types of resistance were taken complete whitening, hinge and lack of resistance. Goal. The purpose of the study is to determine the causes of emergencies, including those recorded as road accidents. For this purpose it is offered to carry out the analysis of natural frequencies of the cablestayed bridge on its different types of contact (resistance) with columns. The object of this study is a cablestayed bridge, which has been in operation for 45 years. The bridge is a system of three types of elements: pylon, span and columns. The subject of the study is the spectrum of natural frequencies of the bridge according to its various models. Methodology. The research was performed using the methods of oscillations and finite elements, as well as the methods developed by the author for building models of complex machine-building systems. Results. According to the results of the performed researches, mathematical threedimensional finiteelement models of parts and the whole system of the bridge were made for different types of resistance, natural frequencies for each system were obtained. The conducted research provided grounds for conclusions on concretization of the causes of emergency situations and directions for their avoidance. Originality. Regarding the type of developed models of the cablestayed bridge, we note their uniqueness. Due to the existing personalities of the models used, it is possible to model three states of interaction of parts of the system. To conduct a study with a high degree of reliability of the real model, you need to have available data on the types of connections of its elements. This is possible with the help of unique author’s methods of model construction and use of universal possibilities of the finite element method. Research of the bridge by other methods did not allow to solve the set tasks on emergence of emergency situations. Practical value. The results of the work have a direct practical application. Based on the results of the work, a conclusion was made on measures to increase the troublefree operation of the system and measures to avoid the occurrence of an emergency situation.

Tissue section lifting for electron microscopy

1978 ◽  
Vol 36 (2) ◽  
pp. 86-87
Author(s):  
Adrian F. van Dellen
Keyword(s):  
Infectious Disease ◽  
Electron Microscopy ◽  
Tissue Culture ◽  
Organ System ◽  
Surrounding Tissue ◽  
Paraffin Sections ◽  
Surface Areas ◽  
Specific Determination ◽  
High Degree ◽  
Accuracy And Repeatability

The morphologic pathologist may require information on the ultrastructure of a non-specific lesion seen under the light microscope before he can make a specific determination. Such lesions, when caused by infectious disease agents, may be sparsely distributed in any organ system. Tissue culture systems, too, may only have widely dispersed foci suitable for ultrastructural study. In these situations, when only a few, small foci in large tissue areas are useful for electron microscopy, it is advantageous to employ a methodology which rapidly selects a single tissue focus that is expected to yield beneficial ultrastructural data from amongst the surrounding tissue. This is in essence what "LIFTING" accomplishes. We have developed LIFTING to a high degree of accuracy and repeatability utilizing the Microlift (Fig 1), and have successfully applied it to tissue culture monolayers, histologic paraffin sections, and tissue blocks with large surface areas that had been initially fixed for either light or electron microscopy.

Electron Microscopy in Molecular Biology

1967 ◽  
Vol 25 ◽  
pp. 2-3
Author(s):  
Cecil E. Hall
Keyword(s):  
Electron Microscopy ◽  
Molecular Biology ◽  
Noise Level ◽  
Molecular Structures ◽  
Material Structure ◽  
The Arts ◽  
Shadow Casting ◽  
Electron Image ◽  
High Degree ◽  
Very High

The visualization of organic macromolecules such as proteins, nucleic acids, viruses and virus components has reached its high degree of effectiveness owing to refinements and reliability of instruments and to the invention of methods for enhancing the structure of these materials within the electron image. The latter techniques have been most important because what can be seen depends upon the molecular and atomic character of the object as modified which is rarely evident in the pristine material. Structure may thus be displayed by the arts of positive and negative staining, shadow casting, replication and other techniques. Enhancement of contrast, which delineates bounds of isolated macromolecules has been effected progressively over the years as illustrated in Figs. 1, 2, 3 and 4 by these methods. We now look to the future wondering what other visions are waiting to be seen. The instrument designers will need to exact from the arts of fabrication the performance that theory has prescribed as well as methods for phase and interference contrast with explorations of the potentialities of very high and very low voltages. Chemistry must play an increasingly important part in future progress by providing specific stain molecules of high visibility, substrates of vanishing “noise” level and means for preservation of molecular structures that usually exist in a solvated condition.

A High Angle, Double Tilting Cold Stage for the AEI EM7

1974 ◽  
Vol 32 ◽  
pp. 450-451
Author(s):  
P.R. Swann ◽  
A.E. Lloyd
Keyword(s):  
Habit Plane ◽  
Temperature Control ◽  
Tilt Angle ◽  
Cooling System ◽  
Thermal Drift ◽  
High Angle ◽  
Cold Stage ◽  
High Degree ◽  
Better Than

Figure 1 shows the design of a specimen stage used for the in situ observation of phase transformations in the temperature range between ambient and −160°C. The design has the following features a high degree of specimen stability during tilting linear tilt actuation about two orthogonal axes for accurate control of tilt angle read-out high angle tilt range for stereo work and habit plane determination simple, robust construction temperature control of better than ±0.5°C minimum thermal drift and transmission of vibration from the cooling system.

New Aspects in the Design of Electron Optical Magnification Systems

1972 ◽  
Vol 30 ◽  
pp. 606-607
Author(s):  
Willem H.J. Andersen
Keyword(s):  
Electron Microscope ◽  
Imaging System ◽  
Chromatic Aberration ◽  
Research Tool ◽  
Energy Losses ◽  
Objective Lens ◽  
Theoretical Limit ◽  
Optical Magnification ◽  
Chromatic Aberrations ◽  
High Degree

Electron microscope design, and particularly the design of the imaging system, has reached a high degree of perfection. Present objective lenses perform up to their theoretical limit, while the whole imaging system, consisting of three or four lenses, provides very wide ranges of magnification and diffraction camera length with virtually no distortion of the image. Evolution of the electron microscope in to a routine research tool in which objects of steadily increasing thickness are investigated, has made it necessary for the designer to pay special attention to the chromatic aberrations of the magnification system (as distinct from the chromatic aberration of the objective lens). These chromatic aberrations cause edge un-sharpness of the image due to electrons which have suffered energy losses in the object.There exist two kinds of chromatic aberration of the magnification system; the chromatic change of magnification, characterized by the coefficient Cm, and the chromatic change of rotation given by Cp.

Cytoplasmic Organization in the Receptor Cells of the Crista Ampullaris

1972 ◽  
Vol 30 ◽  
pp. 60-61 ◽  
Author(s):  
Robert F. Dunn
Keyword(s):  
Fine Particles ◽  
Apical Cell ◽  
Apical Region ◽  
Receptor Cells ◽  
Cuticular Plate ◽  
Morphological Organization ◽  
Crista Ampullaris ◽  
Cytoplasmic Organization ◽  
High Degree ◽  
General Appearance

Receptor cells of the cristae in the vestibular labyrinth of the bullfrog, Rana catesbiana, show a high degree of morphological organization. Four specialized regions may be distinguished: the apical region, the supranuclear region, the paranuclear region, and the basilar region.The apical region includes a single kinocilium, approximately 40 stereocilia, and many small microvilli all projecting from the apical cell surface into the lumen of the ampulla. A cuticular plate, located at the base of the stereocilia, contains filamentous attachments of the stereocilia, and has the general appearance of a homogeneous aggregation of fine particles (Fig. 1). An accumulation of mitochondria is located within the cytoplasm basal to the cuticular plate.

Computer Reconstruction of the Cellular Architecture of the Daphnia Magna Optic Ganglion

1975 ◽  
Vol 33 ◽  
pp. 284-285
Author(s):  
E. R. Macagno ◽  
C. Levinthal
Keyword(s):  
Daphnia Magna ◽  
Genetic Background ◽  
Compound Eye ◽  
Synaptic Connectivity ◽  
Serial Sections ◽  
Cross Sectional ◽  
Small Crustacean ◽  
Optic Ganglion ◽  
Structural Invariance ◽  
High Degree

The optic ganglion of Daphnia Magna, a small crustacean that reproduces parthenogenetically contains about three hundred neurons: 110 neurons in the Lamina or anterior region and about 190 neurons in the Medulla or posterior region. The ganglion lies in the midplane of the organism and shows a high degree of left-right symmetry in its structures. The Lamina neurons form the first projection of the visual output from 176 retinula cells in the compound eye. In order to answer questions about structural invariance under constant genetic background, we have begun to reconstruct in detail the morphology and synaptic connectivity of various neurons in this ganglion from electron micrographs of serial sections (1). The ganglion is sectioned in a dorso-ventra1 direction so as to minimize the cross-sectional area photographed in each section. This area is about 60 μm x 120 μm, and hence most of the ganglion fit in a single 70 mm micrograph at the lowest magnification (685x) available on our Zeiss EM9-S.

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