Investigating the parameters of electron beams in the presence of ion compensation of the charge using the “hole chamber” method

The parameters of electron beams produced by a hollow-anode gas-discharge electron gun based on a glow discharge and operated in an ion focusing mode at medium and low vacuum have been investigated. The “hole chamber” method is proposed. Using a device based on this method, it is possible to measure the electron beam parameters with a high efficiency under conditions of ion focusing when testing the performance of the gas-discharge electron gun in technological processes.     

Modernization of the Duoplasmatron of the И-2 Linear Accelerator

A modified ion source of the duoplasmatron type used in the -2 linear accelerator for generating a proton beam is described. Improving the designs of the electrodes, the magnetic circuit, the gas-supply channel, and the electromagnetic valve has made it possible to considerably increase the service life of the source (up to 10⁷ pulses), to reduce the consumption of hydrogen (up to 10 cm³/h at a pulse repetition rate of 1 Hz), and to increase the stability and reliability of the source operation in the regime of everyday service of the linear accelerator in applied research as an injector of the ITEP U-10 proton synchrotron.     

Dimensioning of the intermediate states of the machined phases “DISMP” approach

In manufacturing practice for each machining operation, transfer techniques are extensively used for the allocation of manufacturing specification tolerance type and value. This paper focuses more on tolerance type which is the basis for a coherent and complete tolerancing process. We developed an algorithmic method called “DISMP” in order to generate the necessary types of manufacturing specifications that guarantee the respect of the functional requirements. A geometric variation model, based on the invariants degrees of freedom (DOFs) of the datum reference frames (DRF) and the toleranced surfaces serves to specify the two extremities of the tolerance chain. The identification of the controlled DOFs (Cont-DOFs) of the positioning reference frames in each machining phases and also the constrained DOFs (Cons-DOFs) of each machined surface contributes to the development of the way linking between the functional toleranced surface and its functional DRF. To generate the appropriate manufacturing geometric specifications, our method can be divided in five steps. We started by the translation of the ISO functional specification using the topologically and technologically related surfaces rules “TTRS” (Step 1: M1). Mapping the manufacturing process (Step 2: M2 and M3) requires the identification of the Cons-DOFs of the machined surfaces and those controlled by the positioning surfaces “Cont-DOFs” in each phase. The search of all chain links, which constitute the tolerance chain, is realized on Step3 (M4 and M5). Then, in step 4 (M6), we generate ISO standardized manufacturing specification. The fifth step (M7) draft technological constraints related to the manufacturing process, i.e., the case where there are inversion in the order between the toleranced surfaces and its DRF. Finally, we present the manufacturing process phases with ISO standards requirements.     

PATENT LAW of the People''''s Republic of China

Article 1. This Law is enacted to protect patent rights for inventions-creations, to encourage inventioncreation, to foster the spreading and application of inventions-creations, and to promote the development of science and technology, for meeting the needs of the construction of socialist modernization. Article 2. In this Law, "inventions-creations" mean inventions, utility models and designs.     

Effect of Hydrostatic Pressure on the Optical Parameters of Fiber-Optic Cables for the Calibration System of the НТ-200 Neutrino Telescope

The effect of hydrostatic pressure and its gradient on the optical parameters of fiber-optic cables for the calibration system of the -200 Baikal neutrino telescope was investigated. The mean delay time of the light signal in the fiber-optic cables of the system is shown to be virtually constant at absolute pressures varying from 0 to 150 atm; incidentally, the average signal amplitude decreases by 5%. When the pressure difference changes from 0 to 7 atm, the average signal delay time increases by 0.5 ns, and the average signal amplitude decreases by 17%.     

New Method to Measure the Fill Level of the Ball Mill Ⅱ-Analysis of the Vibration Signals

The exact measurement of the fill level is the key and basic problem for automatic control and optimized operation of the coal pulverizing system. Because the ball mill pulverizing system is non-linearity, long time delay and time-varying, the reliable and effective method for measuring the fill level was lacked at present. In order to reduce the influence by various factors on measuring the fill level and improve the measuring accuracy of the fill level, a novel characteristic variable is proposed. A set o...     

Facility for investigating the propagation of sound in the surface layer of the earth’s atmosphere

The facility is intended for investigating the propagation of sound waves in the surface layer of the Earths atmosphere. It permits the directional radiation, and recording, of high-level audio-frequency sound. The maximum sound level (referred to a distance of 1 m) is as high as 151 dB; the antenna beamwidth is 6° to 16°, depending on the frequency; the side-lobe level does not exceed –20 dB; and the lengths of the investigated propagation paths, with various underlying surfaces, are up to 3 km.__________Translated from Pribory i Tekhnika Eksperimenta, No. 2, 2005, pp. 130–132.Original Russian Text Copyright © 2005 by Krasnenko, Kudryavtsev, Mananko.     

Measurement of the Background Level in the Spectra of Internal-Conversion Electrons Using the МАС-1 Microscope Complex

A method for measuring the spectral lines in an -50 photoemulsion plate with a varying background level is described. The -ray spectrograph of the Joint Institute for Nuclear Research's Laboratory of Nuclear Problems, was used to record the spectra. The plate was exposed to internal-conversion electrons produced by the decay of erbium isotopes (erbium fraction). The spectral measurements were performed using the -1 microscope complex. The distribution of the background level over the plate surface was measured. Using the L-structure of the -ray line of ¹⁶¹Ho with an energy of 175.5 keV as an example, it was shown that the accuracy of the intensity measurements was 10% or better. The accuracy in measuring the background level governed the accuracy in identifying the multipolarity of nuclear transitions. A precision TV system for data readout based on a 768 × 576 pixel CCD matrix provided a measurement accuracy of 0.5 m for both coordinates.     

Influence of the Mechanical Seals on the Dynamic Performance of Rotor–Bearing Systems

In this paper, to consider the effects of mechanical seals, a lumped-mass model and the transfer matrix method are used to establish the equations for the dynamics performance of rotor bearing system. The general inverted iteration method is also used to solve the eigenvalue problem of these equations. To check the response of the rotor bearing system under unbalance motivation, the Gauss method is used to calculate the dynamic response of the constrained vibration. The results, based on the dynamic properties calculation of a typical mechanical spiral seal, such as stiffness coefficients and damping coefficients, exert the influence of the mechanical seal on the rotor bearing system of the high-speed machinery. Meanwhile, some structure parameters that may affect the dynamic performance and forced vibration under unbalance motivation of the rotor bearing system considering mechanical seals are analyzed in the paper. The analysis results show that the mechanical seal more or less has effects on the rotor bearing system. The mechanical seal has much more effects on the flexible rotor bearing system than on the rigid one. For instance, in a certain case, if the effects of the mechanical seal were taken into account, the system s critical speed may increase by 70 80%.     

An Automated Setup for Investigating the Temperature Dependence of the Permittivity Spectra of Polar Liquids in the Range of 0.1–1.25 GHz

An automated setup for measurements of the temperature dependences of permittivity spectra is described. It uses an irregular microstrip resonator and allows measurements to be performed at a junction of methods using lumped elements and electrodynamic systems with distributed parameters. Measurements can be carried out without expensive thermostabilization devices in the temperature range of 200–350 K with a step of 1 K. The temperature dependences of the permittivity of polar liquids—water, methanol, and ethanol, whose dielectric relaxation regions lie within the frequency range of 0.1–1.25 GHz—are presented. Comparing the measured values of the permittivity to the Debye curve calculated from the reference data shows agreement within the limits of 3% for and 1% for . The random error of measurements was 2–3% for and 5–7% for .     

Neural network classification of hyperspectral images on the basis of the Hilbert–Huang transform

The method of image classification with its preliminary transformation to principal components and with the use of the Hilbert–Huang transform is studied by an example of neural network classification of a hyperspectral image. The efficiency of the method is demonstrated through comparisons with traditional methods of neural network classification with the use of spectral components and principal components without involving spatial information as features. Radial-basis and complex neural networks are used for classification.     

Use of the Reflection of Near‐Infrared Light for the Nondestructive Examination of Blood Flow and Other Applications

Abstract

Reflection of near‐infrared light is measured by commercial equipment. We found that samples in motion and at rest show differences in the intensity of reflection of a laser beam. This may suggest the possibility of its use to detect organ necrosis in vivo. In addition, we find the possibility of the use of this reflection of the near‐infrared light for the non‐destructive inspection of internal changes in perishables, e.g., their degree of ripeness.     

A Theoretical Study of the Effect of Offset Loads on the Performance of a 120° Partial Journal Bearing

Reynolds' equation for a 120° partial journal bearing of the clearance type having an L/D ratio of 1 is solved numerically to determine the effect of positioning circumferentially the line of action of the load at various points along the bearing arc. The influence of the load position (α/β) on film thickness, eccentricity, journal position, friction, flow, temperature rise, and maximum film pressure is investigated and performance curves given. It is shown that the position of the load has a significant effect on bearing performance.     

Study of the punch–die clearance influence on the sheared edge quality of thick sheets

Sheet metal punching is an important industrial process for forming mechanical parts. Aimed at generating holes on thick sheets, punching process has been considered as a promising solution for the heavy industrial sector. The correct punching parameters choice has a direct influence on the hole quality. Since there exists rarely an analytical expression describing the relationships between these process parameters, the forming variable choice follows a series of costly try-and-error procedures on the workshop floor. The numerical simulation is a powerful tool that helps the forming engineers at the try-and-error procedures. This work shows the possibility of using FE-simulations to reduce the number of experiments that has to be conducted propitiating an increased understanding concerning some punching process parameters influence. The aim is the study of the clearance influence on the punched holes quality, 8 mm LNE38 sheet metal. Clearances of 0.2% up to 15% between the punch and die were analyzed. The influence of the punch–die clearance on the crack propagation was also analyzed, and the results were in agreement with the literature, i.e., good results for gaps within the traditional ideal range and occurrence of burr for clearance of 15%.     

Modeling and analysis of the effects of processing parameters on the performance characteristics in the high pressure die casting process of Al–SI alloys

The high pressure die casting (HPDC) process has achieved remarkable success in the manufacture of aluminum–silicon (Al–SI) alloy components for the modern metal industry. Mathematical models are proposed for the modeling and analysis of the effects of machining parameters on the performance characteristics in the HPDC process of Al–SI alloys which are developed using the response surface methodology (RSM) to explain the influences of three processing parameters (die temperature, injection pressure and cooling time) on the performance characteristics of the mean particle size (MPS) of primary silicon and material hardness (HBN) value. The experiment plan adopts the centered central composite design (CCD). The separable influence of individual machining parameters and the interaction between these parameters are also investigated by using analysis of variance (ANOVA). With the experimental values up to a 95% confidence interval, it is fairly well for the experimental results to present the mathematical models of both the mean particle size of primary silicon and its hardness value. Two main significant factors involved in the mean particle size of primary silicon are the die temperature and the cooling time. The injection pressure and die temperature also have statistically significant effect on microstructure and hardness.     

The Mathematical Simulation and Study of the Electrical Resistance of the Friction Zone of the Hip Joint Endoprosthesis with a Metal–Metal Friction Pair

The paper has described a model of the static load on the hip joint that takes into account the anthropological parameters and a mathematical model of the change in the resistance of the endoprosthesis under the influence of an external load at different rotation angles of the cup component. The theoretical studies have revealed the character of the changes and assessed the possible ranges of variations in the diagnostic parameter that are required to develop diagnostic equipment and methods for testing and interpreting diagnostic information during the tribotesting of individual types of implants.     

Estimation of operation capability of the ball pin of the “Volzhanin-32901” bus with relation to fatigue strength

The design formulas for calculation of the fatigue strength of the ball pins of the bus steering system are given. The analysis of failures and calculation of the bus “Volzhanin-32901” is represented as an example. The formulas assume the variables of stress appearing while driving the transport vehicle and the stresses of bearing and bending.     

A Model for the Assessment of Wheel–Rail Contact in the Presence of Solid Contaminants

An analytical model for the assessment of a contact in the presence of a solid contaminant is presented, mainly aimed at studying the damage to railway wheels and rails operating in third-body-contaminated environments. The model, developed under 2D plane strain idealization, includes multiple evenly spaced rigid cylindrical contaminant bodies entrapped between two elastic cylinders. It allows a very fast calculation of the pressure distribution on the surfaces in contact and it can be used for evaluating the stress field in the subsurface region, at both the small scale of the contact between the main body and the contaminant body and the full scale of the contact between the two main bodies. The model was validated by comparison with finite element (FE) analyses, showing its accuracy. Some examples of application showed the model’s ability to predict the limit of the influence of the solid contaminant bodies and the depth where cyclic plasticity phenomena occur in wheel–rail contacts.     

Experimental Depiction of the Hypothesis of Flake-Like Wear Debris Generation in Rolling Contact Fatigue of the Rail–Wheel Contact Interface

Flake-like particles represent a common type of wear debris generated during the rolling contact fatigue wear test using a twin-disc test rig. It is argued that these flake-like particles are generated during the delamination process due to plastic shear strain accumulation at the wearing surfaces. This hypothesis has been developed in the last decades to explain the particle generation mechanism, yet it has not been proven conclusively. This research provides strong experimental evidence of the creation processes of wear debris propagation, aggregation, transfer, and compaction, therefore confirming the existing hypothesis and enhancing the understanding of wear mechanisms in the rolling contact interface.