Kinematic Analysis of 3D Printing Mechanisms

2015 ◽  
Author(s):  
Ilie Talpasanu ◽  
Stephen Chomyszak
Keyword(s):  
3D Printing ◽  
Kinematic Analysis ◽  
Input Output ◽  
Gear Teeth ◽  
The Matrix ◽  
Angular Velocities ◽  
Gear Box ◽  
The Difference ◽  
Student Projects

The paper presents a novel technique for the kinematic analysis of a geared mechanism manufactured through 3D printing technology. In the syllabus of the undergraduate 3D Printing course, one of the student projects is to manufacture a spur Norton type gear box which includes a planetary mechanism for engaging its three planets, thus three output velocities for the gear box are obtained. The connected elements (carriers, gears, planets) are fabricated without any involvement of assembly operation. At the prototype stage, a CAD model of the mechanism is created and a search for abilities and limitations of the mechanism are required. The analysis of abilities of motion includes determination of mechanism mobility (DOF). A step by step simple technique is presented for determination of the rank for the matrix of coefficients from the kinematic equations. Thus, the DOF is the difference between the number columns and the rank previously determined. The steps required in the analysis are: numbering of links and joints, graph attached to mechanism, matrix of incidence cycles-nodes in graph, and determination of its rank by using Mathematica commands. For the set of base cycles are automatically generated independent scalar equations. The matrix, denoted velocity matroidal, has the coefficients for the mechanism’s unknown absolute angular velocities-determined based on an analogy to a system of parallel forces from static equilibrium, angular velocities being considered analog to the “forces“. The relations between the input-output links’ absolute angular velocities are determined. The coefficients in the kinematic equations for velocities are written as function of gear ratios. The number of gear teeth can be selected also for the desired input-output speed ratios.

scholarly journals HOMEMADE FIREARMS PRODUCED USING THE 3D PRINTING METHOD – THEIR CONSTRUCTION AND THE PECULIARITIES OF FORENSIC EXAMINATION

2020 ◽  
pp. 381-392
Author(s):  
P. Giverts
Keyword(s):  
3D Printing ◽  
New Technology ◽  
3D Printer ◽  
Wide Spread ◽  
Special Equipment ◽  
Forensic Examination ◽  
Special Knowledge ◽  
The Difference ◽  
Printing Method

The development of a new technology of material processing known as 3D printing in 2013 lead to posting on the Internet blueprints of the first pistol made with the use this technology. The pistol got the name Liberator. Within the first two days after the post, the blueprints of this pistol were downloaded more than a hundred thousand times. The difference of this construction from other constructions is that all the parts, except the firing pin, are printed on the 3D printer. For manufacturing this type of pistols special equipment (which has become easily available lately) is needed, as well as the knowledge and skill to operate it. At the same time, no special knowledge about the development and manufacturing of firearms is necessary. Availability of ready blueprints (the programs for printing the elements in 3D printer) without the need to do manual or machine treatment, lead to the wide spread of this type of homemade firearms. The law enforcements of many countries have already got cases of illegal trafficking of homemade firearms made with the use of 3D printing technology. The article discusses the construction features of Liberator pistol, as well as the peculiarities of its forensic examination. Special attention is paid to the problem of reliability and durability of this type of pistols. The possibility of damage or destruction of the pistol construction during a shot was investigated. The influence of different parameters, such as the size of the pistol, the material of its elements, the caliber of the cartridge on the possible destruction of the pistol, was also discussed. The damages in the pistols, made of different polymers, were illustrated in this article by the results of investigations taken from a few foreign professional sources. The problem of establishing the fact of a shot, which had been made from pistol printed in 3D printer, before the evidence came for forensic examination, was discussed. The article deals with the problem of the influence of this shot on the possibility of determination of the constriction durability and with the question if the evidence meets the criteria of firearms. Possible defects in the examined evidences, which should be checked be the examiners before the experimental shot, were pointed out.

Determination of Force Constants of Octahedral XY6 Molecules by the GF Matrix Method

2005 ◽  
Vol 60 (11-12) ◽  
pp. 819-822 ◽  
Author(s):  
Fatih Ucun ◽  
M. Gökhan Şengül
Keyword(s):  
Matrix Method ◽  
Molar Mass ◽  
Interaction Force ◽  
Force Constants ◽  
Complex Ions ◽  
Slowing Down ◽  
The Matrix ◽  
The Difference ◽  
Raphson Method

The force constants of the internal coordinates of octahedral XY6 molecules and complex ions were calculated by using the GF matrix method. The matrix solutions were found by means of a computer program using the Newton-Raphson method. From the calculations it has been observed that the bond stretch force constants of octahedral XF6 molecules and XY6 complex ions having the same centre X atom decrease with the increasing molar mass of the centre X atom for the former and the ligand Y atom for the latter, respectively. This was attributed to the slowing down of the molecule with increasing molar mass of the molecule as the whole. In addition we have concluded that the difference of squares of the vibration frequencies ν1 and ν2 of octahedral XY6 complex ions decreases with the increasing mass of the Y atom since the interaction force constant of these ions decreases with the increasing mass.

Lateral resolution of the electron microbeam analysis

1978 ◽  
Vol 36 (1) ◽  
pp. 542-543
Author(s):  
H.J. Dudek
Keyword(s):  
Quantitative Analysis ◽  
Depth Resolution ◽  
Lateral Resolution ◽  
Cylindrical Particle ◽  
Correction Procedure ◽  
X Ray ◽  
Element Concentrations ◽  
Microbeam Analysis ◽  
The Matrix

The chemical inhomogenities in modern materials such as fibers, phases and inclusions, often have diameters in the region of one micrometer. Using electron microbeam analysis for the determination of the element concentrations one has to know the smallest possible diameter of such regions for a given accuracy of the quantitative analysis.In th is paper the correction procedure for the quantitative electron microbeam analysis is extended to a spacial problem to determine the smallest possible measurements of a cylindrical particle P of high D (depth resolution) and diameter L (lateral resolution) embeded in a matrix M and which has to be analysed quantitative with the accuracy q. The mathematical accounts lead to the following form of the characteristic x-ray intens ity of the element i of a particle P embeded in the matrix M in relation to the intensity of a standard S

Determination of the phase structure of polymerblends by electron microscopy

1978 ◽  
Vol 36 (1) ◽  
pp. 492-493
Author(s):  
Dr. G. Kaemof
Keyword(s):  
Screw Extruder ◽  
Electron Microscopic ◽  
Thin Sections ◽  
Single Screw Extruder ◽  
Transmission Electron ◽  
The Matrix ◽  
Twin Screw ◽  
Special Case ◽  
Microscopic Investigations

A mixture of polycarbonate (PC) and styrene-acrylonitrile-copolymer (SAN) represents a very good example for the efficiency of electron microscopic investigations concerning the determination of optimum production procedures for high grade product properties.The following parameters have been varied:components of charge (PC : SAN 50 : 50, 60 : 40, 70 : 30), kind of compounding machine (single screw extruder, twin screw extruder, discontinuous kneader), mass-temperature (lowest and highest possible temperature).The transmission electron microscopic investigations (TEM) were carried out on ultra thin sections, the PC-phase of which was selectively etched by triethylamine.The phase transition (matrix to disperse phase) does not occur - as might be expected - at a PC to SAN ratio of 50 : 50, but at a ratio of 65 : 35. Our results show that the matrix is preferably formed by the components with the lower melting viscosity (in this special case SAN), even at concentrations of less than 50 %.

Polishing process effect on the image of dispersed precipitates

1984 ◽  
Vol 42 ◽  
pp. 534-535
Author(s):  
C.T. Hu ◽  
C.W. Allen
Keyword(s):  
Matrix Material ◽  
Specimen Preparation ◽  
Second Phase ◽  
Precipitate Particle ◽  
Polishing Process ◽  
Second Phase Particles ◽  
The Matrix ◽  
Surface Profiles ◽  
Thinning Process

One important problem in determination of precipitate particle size is the effect of preferential thinning during TEM specimen preparation. Figure 1a schematically represents the original polydispersed Ni3Al precipitates in the Ni rich matrix. The three possible type surface profiles of TEM specimens, which result after electrolytic thinning process are illustrated in Figure 1b. c. & d. These various surface profiles could be produced by using different polishing electrolytes and conditions (i.e. temperature and electric current). The matrix-preferential-etching process causes the matrix material to be attacked much more rapidly than the second phase particles. Figure 1b indicated the result. The nonpreferential and precipitate-preferential-etching results are shown in Figures 1c and 1d respectively.

Kinematic Approximations in TED and RHEED Analysis of Reconstructed Surfaces

1990 ◽  
Vol 48 (2) ◽  
pp. 396-397
Author(s):  
L. -M. Peng ◽  
M. J. Whelan
Keyword(s):  
Electron Diffraction ◽  
Kinematic Analysis ◽  
Incident Beam ◽  
High Energy ◽  
Energy Electron ◽  
Great Success ◽  
High Energy Electron ◽  
Kinematic Approximation ◽  
Reconstructed Surfaces

In recent years there has been a trend in the structure determination of reconstructed surfaces to use high energy electron diffraction techniques, and to employ a kinematic approximation in analyzing the intensities of surface superlattice reflections. Experimentally this is motivated by the great success of the determination of the dimer adatom stacking fault (DAS) structure of the Si(111) 7 × 7 reconstructed surface.While in the case of transmission electron diffraction (TED) the validity of the kinematic approximation has been examined by using multislice calculations for Si and certain incident beam directions, far less has been done in the reflection high energy electron diffraction (RHEED) case. In this paper we aim to provide a thorough Bloch wave analysis of the various diffraction processes involved, and to set criteria on the validity for the kinematic analysis of the intensities of the surface superlattice reflections.The validity of the kinematic analysis, being common to both the TED and RHEED case, relies primarily on two underlying observations, namely (l)the surface superlattice scattering in the selvedge is kinematically dominating, and (2)the superlattice diffracted beams are uncoupled from the fundamental diffracted beams within the bulk.

Tem analysis of multiple-energy arsenic implanted and Rta'd silicon

1987 ◽  
Vol 45 ◽  
pp. 246-247
Author(s):  
R.A. Herring
Keyword(s):  
Device Fabrication ◽  
High Concentration ◽  
Tem Analysis ◽  
Defect Clusters ◽  
High Fluences ◽  
Small Defect ◽  
Before And After ◽  
The Matrix ◽  
The Difference ◽  
Factor Type

Rapid thermal annealing (RTA) of ion-implanted Si is important for device fabrication. The defect structures of 2.5, 4.0, and 6.0 MeV As-implanted silicon irradiated to fluences of 2E14, 4E14, and 6E14, respectively, have been analyzed by electron diffraction both before and after RTA at 1100°C for 10 seconds. At such high fluences and energies the implanted As ions change the Si from crystalline to amorphous. Three distinct amorphous regions emerge due to the three implantation energies used (Fig. 1). The amorphous regions are separated from each other by crystalline Si (marked L1, L2, and L3 in Fig. 1) which contains a high concentration of small defect clusters. The small defect clusters were similar to what had been determined earlier as being amorphous zones since their contrast was principally of the structure-factor type that arises due to the difference in extinction distance between the matrix and damage regions.

FRACTIONAL DETERMINATIONS OF URINARY 17-KETOSTEROIDS IN HYPEREMESIS GRAVIDARUM

1962 ◽  
Vol 41 (1) ◽  
pp. 123-128 ◽  
Author(s):  
Pentti A. Järvinen ◽  
Sykkö Pesonen ◽  
Pirkko Väänänen
Keyword(s):  
Hyperemesis Gravidarum ◽  
First Trimester ◽  
Control Group ◽  
Before And After ◽  
Daily Urine ◽  
First Trimester Of Pregnancy ◽  
The Difference

ABSTRACT The fractional determination of 17-ketosteroids in the daily urine was performed in nine cases of hyperemesis gravidarum and in four control cases, in the first trimester of pregnancy both before and after corticotrophin administration. The excretion of total 17-KS is similar in the two groups. Only in the hyperemesis group does the excretion of total 17-KS increase significantly after corticotrophin administration. The fractional determination reveals no difference between the two groups of patients with regard to the values of the fractions U (unidentified 17-KS), A (androsterone) and Rest (11-oxygenated 17-KS). The excretion of dehydroepiandrosterone is significantly higher in the hyperemesis group than in the control group. The excretion of androstanolone seems to be lower in the hyperemesis group than in the control group, but the difference is not statistically significant. The differences in the correlation between dehydroepiandrosterone and androstanolone in the two groups is significant. The high excretion of dehydroepiandrosterone and low excretion of androstanolone in cases of hyperemesis gravidarum is a sign of adrenal dysfunction.

THE SUBJECT FIELD OF INSTITUTIONAL EDUCATION: THE SENSE AND PROSPECTS OF DEVELOPMENT IN UKRAINE

2020 ◽  
pp. 25-38
Author(s):  
Irina Mordous
Keyword(s):  
Decisive Role ◽  
Subject Field ◽  
National Education ◽  
Progressive Development ◽  
Separate Area ◽  
Economic Transformations ◽  
The Difference ◽  
The Individual ◽  
Political Economic

The development of modern civilization attests to its decisive role in the progressive development of institutions. They identified the difference between Western civilization and the rest of the world. Confirmation of the institutional advantages of the West was its early industrialization. The genesis and formation of institutionalism in its ideological and conceptualmethodological orientation occurs as a process alternative to neoclassic in the context of world heterodoxia, which quickly spread in social science. Highlighting institutional education as a separate area of sociocultural activity is determined by the factor of differentiation of institutional theory as a whole. A feature of institutional education is its orientation toward the individual and his/her transformation into a personality. The content of institutional education is revealed through the analysis of the institution, which includes a set of established customs, traditions, ways of thinking, behavioral stereotypes of individuals and social groups. The dynamics of socio-political, economic transformations in Ukraine requires a review of the foundations of national education and determination of the prospects for its development in the 21st century in the context of institutionalism.

Results of studying the dimensional accuracy of the bases of complete removable prostheses made using 3D printing and traditional technologies

2020 ◽  
pp. 34-39
Author(s):  
Vokulova Yu.A. Vokulova ◽  
E.N. Zhulev
Keyword(s):  
3D Printing ◽  
Traditional Method ◽  
Laser Scanning ◽  
Laser Scanner ◽  
Digital Technologies ◽  
Dimensional Accuracy ◽  
3D Printer ◽  
Significance Level ◽  
Average Value ◽  
The Difference

This article presents the results of studying the dimensional accuracy of the bases of complete removable prostheses made using a 3D printer and the traditional method. Bases of complete removable prostheses were made using an intraoral laser scanner iTero Cadent (USA) and a 3D printer Asiga Max UV (Australia). To study the dimensional accuracy of the bases of complete removable prostheses, we used the DentalCAD 2.2 Valletta software. The Nonparametric Wilcoxon W-test was used for statistical analysis of the obtained data. We found that the average value of the difference with the standard for bases made using digital technologies is 0.08744±0.0484 mm. The average value of the difference with the standard for bases made by the traditional method is 0.5654±0.1611 mm. Based on these data, we concluded that the bases of complete removable prostheses made using modern digital technologies (intraoral laser scanning and 3D printer) have a higher dimensional accuracy compared to the bases of complete removable prostheses made using the traditional method with a significance level of p<0.05 (Wilcoxon's W-test=0, p=0.031). Keywords: digital technologies in dentistry, digital impressions, intraoral scanner, 3D printing, ExoCAD, complete removable dentures.

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