Radial Dimension Research Articles

A new method of processing laser scanning data of radial section dimensions for ring forgings

Ring forgings are widely used in petrochemical, power generation, aerospace, nuclear industry and other industrial fields. In the forging process, the radial section size data greatly affect the forging accuracy of ring forgings. Therefore, a new method of processing laser scanning data of radial section dimensions for ring forgings is proposed. Firstly, the information space set of laser scanning data is established. This information space is divided by continuous concentric circles. Secondly, according to the information relationship between the various areas in the information space, the uniform isomorphism factor is defined. By combining the gradient descent method with the uniform isomorphic factor, the undetermined coefficients are solved. Thirdly, the reduction ratio is set according to the density of scanning data points. By combining the reduction ratio with the undetermined coefficients, the number of points needed to be reserved in each area of a concentric circle is determined. The remaining points and the repetitive points in the intersection of two concentric circles are deleted. Finally, the method is repeated until the last point of the laser scanning data. In this way, the laser scanning data of radial section for ring forging is processed. When the method is applied in the experiment, the size data of radial section is extracted from the processing data of laser scanning radial section line. Two groups of dimension data measurement experiment for standard and non-standard ring forgings are carried out respectively. The dimensions measured from the unprocessed and processed data points are compared with true values. The dimensions measured from the processed data have higher accuracy and smaller error. The feasibility of this method is proved.

All‐Optical Spin–Orbit Coupling of Light in Coherent Media Using Rotating Image

AbstractThe possibility of all‐optical spin–orbit coupling (SOC) of light is investigated based on a rotating spinor image traveling through an electromagnetically induced transparency (EIT) medium. It is shown that the paraxial evolution of the spinor image composed of two Laguerre–Gaussian (LG) modes with different frequencies can be analogous with the quantum dynamics of a spin‐1/2 particle with strong and tunable SOC governed by the Pauli equation, where the spin‐up and ‐down states have different effective masses. Using realistic EIT parameters with cold atoms, both the radial inhomogeneity of the strong control field and the atomic density distribution with comparable size are considered. The results confirm that the large group refractive index varying in the radial dimension mimicking the central potential can greatly enhance the spin–orbit interaction, leading to visible spatial quantization of the oppositely oriented spin states, equivalent to the two LG modes.

Compact ${L}$ -Band Relativistic Magnetron With Diffraction Output of TEM Mode

A compact ${L}$ -band relativistic magnetron (RM) with the diffraction output (DO) of the TEM mode is proposed. In this DO configuration, a ridged circular waveguide is used to replace the cylindrical waveguide to decrease its radial dimension. The RF field of the operating $\pi $ -mode is extracted from every resonator cavity and guided to the ridged circular waveguide. Even at the operating frequency of 1.55 GHz, the ridged circular waveguide can reduce the cutoff radius of the RF wave to 73 mm. The output RF field is further effectively converted to the TEM mode by a compact mode converter. Moreover, in the resonant system, a 10-cavity rising-sun slow wave structure (SWS) is applied to lower the phase velocity of the operating spatial harmonic and enhance the mode separation between the operating mode and the adjacent mode. The particle-in-cell (PIC) simulations demonstrate that the practical RM could output a relatively pure TEM mode at the frequency of 1.55 GHz, and its total efficiency is up to 60% with gigawatt radiation power for a diode voltage of 400 kV.

The fundamental building blocks of cortical development are established in human exencephaly.

The presence and status of progenitor/stem cells in excencephalic brain have not been previously examined. Brain sections of excencephalic 17-week fetus were stained for specific stem and mature cell markers. The ventricles were open, the developing cerebral cortex was thin in the radial dimension, and the ventricular surface was undulated. There was a decreased ratio of subventricular/ventricular zone radial glia precursor cells (RGCs; PAX6+ and HOPX+ cells), a decreased number of intermediate progenitor cells (IPCs; TBR2+), a decreased number of neurons (MAP2+), and an increased number of astrocytes (S100b+), compared to the control. MAP2+ neurons, S100b+ astrocytes, and OLIG2+ oligodendrocytes were present within the subventricular zone. This indicates that the underlying condition did not initially preclude radial glial cells from undergoing asymmetric divisions that produce IPCs but halted the developmental progression. RGC and IPC presence in the developing cerebral cortex demonstrates that the fundamental building blocks of cortical formation had been established and that a normal sequence of developmental steps had been initiated in this case of exencephaly. These data expand our understanding of exencephaly etiology and highlight the status of cortical progenitor cells that may be linked to the disorder.

Anatomical Review of Certain Carnations of North Caucasus

The article provides an anatomical review of 32 species of the genus Dianthus L. representatives шт Caucasus, i.e. information about the anatomy of their stem. Most of the studied species have a narrow ecology and are confined to different altitudinal zones. The experience of the introduction of these species in the botanical garden of the Chechen State Pedagogical University of Grozny in the conditions of the steppe climate indicates wide ecological amplitude and potential adaptive capabilities of the species. The main limiting factor in the distribution of these species in natural conditions is probably their low competitiveness. Anatomical signs, apparently, do not have any taxonomic significance. The similarity of the anatomical structure of the stems of the Caucasus carnations is evident even in species that are well differentiated morphologically. Anatomical differences between them are mainly quantitative. The smallest taxonomic values for the anatomical features of carnations are the radial dimensions of the epidermal cells, the mechanical (sclerenchymal) ring, conducting system. The most significant for these purposes are the morphological features: the size of the calyx and capsule, the shape and degree of dissection of the lobule plate, the shape and size of the chaffs.

Integrated 3D foam-like porous Ni3S2 as improved deposition support for high-performance Li–O2 battery

The development of high efficiency air cathode plays important role in regulating the surface electrochemical process to enhance the performance of Li–O2 battery. Herein, we synthesize an integrated porous Ni3S2 on 3D Ni foam substrate through a facile MOF-derived route, the integrated 3D foam-like porous Ni3S2 catalyst can functional as both current collector and catalyst layer. Benefiting from the unique porous structure and the uniform regulate role of the surface electrochemical reaction, the integrated 3D foam-like catalyst cathode delivers nearly 3 times higher discharge capacity and longer cycling performance than that of the pristine Ni foam. More importantly, the morphology of the formed discharge products exhibits lamellar-like structure and has large radial dimension, the Ni3S2 catalyst layer also plays the role of inducing the formation of LiO2 and decreasing the charge overpotential. This study opens a different and facile horizon to fabricate high-efficient air cathode.

Investigation of Ring Touch Mode Capacitive Pressure Sensor With an Electrothermomechanical Coupling Contact Model

Ring touch mode capacitive pressure sensor, characterized by ring stopper and stepped circular diaphragm, is developed to eliminate or greatly alleviate some disadvantages existing in conventional or small-area touch mode capacitive pressure sensor. An electrothermomechanical coupling model is developed to calculate the deformation, stress and so on of the diaphragm, and it is universally available for different touch modes and non-touch mode. The model is with rapid calculation speed and it is verified by a combination of the finite element method (FEM) and boundary element method (BEM). Benefiting from the high calculation speed of the model, optimization designs of the sensor are carried out. By adjusting the height dimensions or radial dimensions, high sensitivity and strength can be achieved by such a sensor in different pressure ranges of interest without changing its planar package size and masks, or achieved in a very wide pressure range by an array composed of such sensors with a same set of process parameters of each sensor. On the other hand, optimal ratios of height dimensions or radial dimensions are acquired, which can suppress significantly the temperature’s influence on sensor operation, and furthermore, the optimal ratios are advisable for different pressure ranges and different material parameters of the sensor.

Design of a passive constant-force mechanism based on a five-bar mechanism

To solve the problem of complex control of an active constant-force mechanism (CFM) and the large radial dimension of a passive CFM, a new type of CFM based on a two-degree-of-freedom five-bar mechanism (FBM) is proposed in this paper, which is called FB-CFM. Its constant force can be realised by superposition of the negative-stiffness mechanism (NSM) and positive-stiffness mechanism (PSM), and the constant-force range can be adjusted by the PSM. The NSM is designed by adding cams and tension springs on the basis of the FBM and has a compact structure. The tension spring moves in parallel and extends when the FBM operates, which produces negative stiffness. The mathematical model of the FB-CFM is simple and accurate, which does not require complicated calculation of flexible body. To verify the feasibility of the research results, the output characteristic of the FB-CFM was tested by simulation and experiment. The results show that the FB-CFM can produce a relatively stable constant force at low-velocity, which provides a basis for the structural design and theoretical research of compact CFMs.

An application of multicriteria optimization in selection of the two-speed two-carrier planetary gear trains

This paper outlines the optimum selection procedure for a two-speed planetary gear train with four external shafts based on two design and operational criteria: radial dimensions and efficiency. The paper outlines how to quickly determine the structure and important basic parameters of two-speed planetary gear trains that meet predefined transmission requirements. The procedure is followed by a numerical example in which the optimal two-speed planetary gear train is selected, defined by the teeth number of the central gears, modules and transmission ratios. The relevance of the presented results is reflected in the fact that these transmissions offer significant advantages in systems which require speed change under load.

Coalescence of Islands of Different Thicknesses in Smectic Nanofilms

In smectic nanofilms, the coalescence of islands (areas thicker than the smectic nanofilm) of different thicknesses and radial dimensions is studied. The initial stage of coalescence (fusion of islands) has a dislocation nature and is associated with changes in the energy of dislocation loops. The second stage of coalescence with the collapse of one of the islands occurs with the increase in the size of the other island. The estimates obtained show that the change in the energy of dislocation loops and the interaction of the surfaces of the smectic nanofilm play the decisive role at this stage. An unexpected effect of displacement of the center of mass of two islands in the process of their coalescence is also discovered. The effect is related to the collective dynamics of the material flows of the islands and the smectic nanofilm.

Analysis on coupled vibration of piezoelectric ceramic stack with two piezoelectric ceramic elements.

A longitudinally polarized piezoelectric ceramic stack with two piezoelectric ceramic elements is an important part of sandwich piezoelectric transducers. The three-dimensional coupled vibration of piezoelectric ceramic stack is analyzed. Since the longitudinal and radial dimensions of particular piezoelectric ceramic stacks are approximately equal, one-dimensional theory cannot be used for analysis. The piezoelectric ceramic stack is analyzed by the equivalent elastic method, which is an approximate analytical method, and it is considered that the coupled vibration of a piezoelectric ceramic stack is composed of equivalent radial and longitudinal vibrations. These two equivalent vibrations are connected by a mechanical coupling coefficient. The radial and longitudinal electromechanical equivalent circuits are obtained, and the resonance frequency equations are derived. The dependency of the radial and longitudinal resonance frequencies on the geometrical dimensions for piezoelectric ceramic stack is analyzed. The height or radius has a large influence on the longitudinal resonance frequency or the radial resonance frequency. Two sets of piezoelectric ceramic stacks are fabricated. The experimental results, COMSOL simulated results, and theoretical results are in good agreement.

Terahertz generation by four-wave mixing and guidance in diatomic teflon photonic crystal fibers

Terahertz radiation generation by four-wave mixing and low-loss propagation in a well optimized photonic crystal fiber has been presented here. Teflon with low-loss in the THz range has been considered where diatomic hexagonal crystalline symmetry in the core region is important for large modal overlap to efficiently generate THz radiation. The core and cladding of the fiber are made of Teflon with slightly different indices both at the pump and idler as well as THz frequencies. The core of the fiber consists of modified Teflon and Polyethylene inclusions of same radial dimension arranged in diatomic lattice with hexagonal symmetry. Input pump and idler fields are chosen to be at the frequencies of standard carbon dioxide and carbon monoxide lasers, respectively. The underlying photonic structure produces high efficiency of ∼15% with respect to pump power and moderately tunable THz radiation at about 9.2 THz within a very short 6.5 m propagation length. The pump power can be varied to tune the THz signal and the idler frequency in certain range. The optimized design also provides a low-loss guidance with propagation and bending losses of less than 1dB/km.

Efficiency modelling and analysis for a novel double-arc bevel gear nutation transmission system for pure electric vehicles

Since more attention has been paid to the development of pure electric vehicles, small and high efficiency of transmission system is the trend. The paper proposes a novel double-arc bevel gear nutation transmission system with two inputs and one output for pure electric vehicles. Compared with the traditional planetary gear transmission, the designed system has advantages of compact structure, small radial dimension and low cost. The nutation transmission of double-arc bevel gears is transformed into a spur planetary gear transmission mechanism with few teeth difference when the inclination angle is equal to zero. Based on kinetic and gear meshing analysis, it is found that the transmission efficiency of the model is related to the nutation gear ratio and the speed ratio of two power sources. The approach of analyzing the efficiency proposed in this paper can provide theoretical basis for the efficiency analysis of the nutation transmission in the future.

Optimization of axial volumetric drive aviation pump

AnnotationThis article discusses a volumetric drive aircraft axial pump and solves the problem of its optimization by the Sobol method. The optimization criteria were the radial dimension and the power expended. In this case, the non-uniformity of the pump operation over time and the variable value of the pressure consumed by the network were taken into account. The last two parameters act as constructive variable parameters. As a result of the work, we obtained a compromise curve. The radial dimension is the power expended.

ПАРАМЕТРИЧНІ ОДНОКАСКАДНІ ГЕНЕРАТОРИ ІМПУЛЬСІВ ТИСКУ ПІДВИЩЕНОЇ ПРОПУСКНОЇ ЗДАТНОСТІ

One of the advantages of the hydropulse devices for the vibration cutter (VC) and the surface deformation hardening of the parts (SDHP), in front of devices with other types of drives (mechanical, pneumatic, electric, etc.) is its small dimensions with significant energy efficiency. This advantage is achieved through the use of high-rigidity springs, such as cut-out (СS), plate (PS) and ring (RS) springs, which, in order to minimize the dimensions of devices, are used in power and distribution units (pressure generators of the pulse pressure (PPG), are combined or made as one part with their power and distribution (PPG) links. The bandwidth Q of PPG used in the hydropulse devices for VC and SDHP is, as a rule, single-stage PPGs of parametric type with valve (facsimile) and spool sealing, respectively, of the first and second degrees of sealing of the locking element (link) of the PPG, determined by its the conditional passage dу, which is regulated by the diameters of the stages of PPG sealing, respectively, the first – d1 and the second – d2 and the negative overlap hв of the spool sealing degree, which is achieved by the magnitude of the positive overlapping hд. One possible way to increase the throughput of single-stage PPGs based on elastic elements of high stiffness is to reduce the course of the locking element of the PPG by eliminating (using a valve seal in the second degree of PPG) or significantly reducing its positive overlap hд, under conditions of application of short high-stiffness springs and conservation stresses arising in the cross sections of their elements at the level of permissible ones. According to the indicated way of increasing the throughput of single-stage PPGs on the basis of elastic high stiffness elements, the design schemes of single-stage PPGs with increased throughput for controlling the hydropulse drives (HPD) of vibration process machines and devices are considered. The basic link of the proposed PPG is the shutter element with a valve (facade) seal, made at the same time or combined with an elastic high stiffness link, for example, cut-through or ring springs. Two types of single-stage PPGs with increased throughput have been developed with the connection diagrams for the HPD (hydrocylinder etc.) power connection at the «outlet» and «inlet». Increased PPG throughput is achieved due to the considerable efforts of the preliminary deformation of the CS or RS and the limitation of their radial and axial dimensions.

Multiscale modeling of a tubular reactor for flow chemistry and continuous manufacturing

Continuous manufacturing of drug substance with the aid of flow chemistry is mostly performed in the tubular reactors and at low flowrates. The laminar flow in the reactor limits micromixing for advancing the reactions and transport phenomena. Reactor scale-up can be performed based on computational simulations and lab scale experimental studies. The residence time distribution and dispersion of the component will be varied at different scales, which require deep understanding of the multiscale phenomena for design, control, and risk analysis.This study is designed to show how modeling can aid the design and risk assessment of flow chemistry process which are often influenced by the Multiphysics of kinetics, heat transfer, and mass transfer. Previous works used experimental methods to study the dispersion and residence time distribution; developed numerical models without considering the Multiphysics and variable fluid properties (i.e. temperature and composition dependent density); or didn't evaluate the scale-up effect and size dependent distribution for reaction in the laminar flow. This study aims to fill the gap and address these issues by developing the first-principle mechanistic modeling.A Fridel-craft acylation reaction for continuous manufacturing of an intermediate for Ibuprofen synthesis is modeled in this study for different sizes of the reactor. Two models were developed for the process step: a semi-distributed lumped model based on space independent approach, and a Finite Element Method (FEM) model based on space dependent approach with variable discrete volumes in radial and axial dimension. A case of model-based scale-up is also studied.The results demonstrate application of mechanistic modeling in evaluating dispersion and residence time distribution in continuous manufacturing of an API. The coupled reaction and Multiphysics modeling evaluated the scale-up limitations, mixing restrictions, and axial dispersions.

Investigation of dimensional accuracy and international tolerance grades of 3D printed polycarbonate parts

In current scenario manufacturing industries has tremendous pressure to shorten the product development life cycle. Fused deposition modeling (FDM) is becoming a solution for the manufacturing of low volume product. Present study, deals with the effect of three important process parameters viz., layer thickness, raster angle and orientation on linear and radial dimension of Poly Lactic Acid (PLA) component. Gray relational analysis (GRA) is employed to find out optimum process parameter condition, which optimize both linear and radial dimension. It was observed that linear dimension had smaller IT grade as compared to the radial dimension due to triangulation error.

Localisation of the Lines of Response in a Continuous Cylindrical Shell PET Scanner.

This work presents a technique for localising the endpoints of the lines of response in a PET scanner based on a continuous cylindrical shell scintillator. The technique is demonstrated by applying it to a simulation of a sensitivity-optimised continuous cylindrical shell PET system using two novel scintillator materials - a transparent ceramic garnet, GLuGAG:Ce, and a LuF3:Ce-polystyrene nanocomposite. Error distributions for the endpoints of the lines of response in the axial, tangential and radial dimension as well as overall endpoint spatial error are calculated for three source positions; the resultant distribution of error in the placement of the lines of response is also estimated.

INFLUENCE OF GEOMETRICAL PARAMETERS OF THE INDUCTOR AND ARMATURE ON THE INDICATORS OF A LINEAR PULSE ELECTROMECHANICAL CONVERTER OF AN ELECTRODYNAMIC TYPE

Purpose. The aim of the paper is to study the influence of geometrical parameters, namely, the number of layers and the cross section of the copper tire of the inductor and the armature coils on the power and speed indicators of a linear pulse electromechanical converter (LPEC) of an electrodynamic type. Methodology. On the basis of the developed chain mathematical model, recurrent relations are obtained for the calculation of interconnected electromagnetic, mechanical and thermal processes of LPEC of an electrodynamic type. The effect of the thickness of a square copper tire and the number of its layers in the inductor and armature coils on the characteristics and characteristics of electrodynamic LPEC is investigated. It is these parameters that determine the number of turns and the axial height of the coils with limited radial dimensions. Results. The influence of the geometrical parameters of the inductor and the armature coils with limited radial dimensions on the electrical and mechanical characteristics of LPEC of an electrodynamic type is established. It has been established that with an increase in the thickness of a rectangular cross-section of copper tire from 1 to 2.5 mm, an increase in the amplitude and pulse of electrodynamic forces (EF) occurs. However, the maximum speed of the armature is the highest at LPEC wound with a 1.5 mm thick tire. The highest efficiency value is demonstrated by LPEC, in which the inductor and armature coils are wound with a 2 mm thick tire. With an increase in the number of layers of the inductor coil tire, the amplitude of the EF decreases significantly, and the magnitude of the EF pulse decreases slightly. As a result, the maximum armature speed, efficiency and temperature rise of the coils are reduced. Originality. It is established that the largest amplitude of the EF is realized in LPEC with the minimum number of layers of tires of the inductor and armature coils. The largest value of the pulse EF occurs when the maximum number of layers of the inductor and the armature. In this case, the largest values of the amplitude and pulse of the EF occur under the condition that the number of tire layers of the inductor and the armature coils are the same. Practical value. It has been established that the greatest efficiency 21.82 % is realized in LPEC, in which the number of tire layers is 2 mm thick with inductor and armature coils are 4. A catapult model for launching an unmanned aerial vehicle was made and tested on the basis of LPEC of an electrodynamic type.

Patterned Vascularization of Embryonic Mouse Forebrain, and Neuromeric Topology of Major Human Subarachnoidal Arterial Branches: A Prosomeric Mapping.

The prosomeric brain model contemplates progressive regionalization of the central nervous system (CNS) from a molecular and morphological ontogenetic perspective. It defines the forebrain axis relative to the notochord, and contemplates intersecting longitudinal (zonal, columnar) and transversal (neuromeric) patterning mechanisms. A checkboard pattern of histogenetic units of the neural wall results, where each unit is differentially fated by an unique profile of active genes. These natural neural units later expand their radial dimension during neurogenesis, histogenesis, and correlative differential morphogenesis. This fundamental topologic framework is shared by all vertebrates, as a Bauplan, each lineage varying in some subtle aspects. So far the prosomeric model has been applied only to neural structures, but we attempt here a prosomeric analysis of the hypothesis that major vessels invade the brain wall in patterns that are congruent with its intrinsic natural developmental units, as postulated in the prosomeric model. Anatomic and embryologic studies of brain blood vessels have classically recorded a conserved pattern of branches (thus the conventional terminology), and clinical experience has discovered a standard topography of many brain arterial terminal fields. Such results were described under assumptions of the columnar model of the forebrain, prevalent during the last century, but this is found insufficient in depth and explanatory power in the modern molecular scenario. We have thus explored the possibility that brain vascularization in rodents and humans may relate systematically to genoarchitectonic forebrain subdivisions contemplated in the prosomeric model. Specifically, we examined first whether early vascular invasion of some molecularly characterized prosomeric domains shows heterochrony. We indeed found a heterochronic pattern of vascular invasion that distinguishes between adjacent brain areas with differential molecular profiles. We next mapped topologically on the prosomeric model the major arterial branches serving the human brain. The results of this approach bear on the possibility of a developmentally-based modern arterial terminology.