scholarly journals Development in broaching technology. Part I. Development of broaching machines and tooling devices

Mechanik ◽  
2021 ◽  
Vol 94 (5-6) ◽  
pp. 6-11
Author(s):  
Wit Grzesik
Keyword(s):  
Control Systems ◽  
Present State ◽  
Experimental Investigations ◽  
Process Variants ◽  
The Third

The paper structured into three parts outlines the present state of the broaching technology. The first part highlights possible process variants for internal and external operations and designs of broaching machines as well as CNC control systems and other advanced automatization forms. The second part will be devoted to the progressive broaching methods such as rotary broaching, hard broaching and MQL application. The third part will discuss some important directions of experimental investigations carrying out for more efficient and reliable broaching processes.

Dispersion Flow in Microchannels

2012 ◽  
Author(s):  
Alfir T. Akhmetov ◽  
Marat V. Mavletov ◽  
Sergey P. Sametov ◽  
Artur A. Rakhimov ◽  
Azat A. Valiev ◽  
...  
Keyword(s):  
Aqueous Phase ◽  
Effective Viscosity ◽  
Complex Structure ◽  
Experimental Investigations ◽  
Dispersed Phase ◽  
Rheological Characteristics ◽  
Dense Structure ◽  
The Third ◽  
Dynamic Blocking ◽  
Oil Emulsions

The work is devoted to experimental investigations of the features of flow of dispersions in microchannels. The paper consists of three parts. In the first part the flow of emulsions in smooth contracting cylindrical microchannels is investigated. It is received that a significant role at dynamic blocking of channels is played by the inclusions comparable by size to the diameter of a narrowing. This is in spite of the fact that their influence on the change of a flow rate of emulsion before blocking is insignificant. In the second part the generation of emulsion in a complex structure of microchannels (micromodels) when water is displaced by composition of hydrocarbon with surfactants is investigated. The experimental dependences of the rheological characteristics of emulsions based on the composition of SAS and water at different concentrations of the aqueous phase can explain blocking of a porous structure by generated emulsion. In the third part a comparison of flow of water-in-oil emulsions with the suspension which was obtained by freezing the microdroplets of the aqueous phase of emulsions was studied. It was found that the blocking of suspension is not as complete as in the case of emulsion. It is explained by deformation of the droplets and by formation of a dense structure, as opposed to suspension of beads, through which hydrocarbon phase is filtered. A small increase in effective viscosity due to solidification of freezing droplets of the dispersed phase was found.

Introduction: Explaining Contingency

2020 ◽  
pp. 1-21
Author(s):  
Alastair Wilson
Keyword(s):  
Present State ◽  
Modal Realism ◽  
The Third ◽  
The Core ◽  
Fourth Part ◽  
Naturalistic Approach ◽  
Big Picture ◽  
Metaphysics Of Modality

The first part of this introduction sketches the main project of the book, and the structure of the arguments for my proposed quantum modal realism. The second part describes the unsatisfying present state of the metaphysics of modality, setting out what I take to be the most serious objections facing the best extant proposals. A naturalistic approach to metaphysics promises to resolve these objections by providing an account of modality that draws only on scientifically respectable theoretical resources. In the third part, I distinguish two big-picture approaches to the metaphysics of modality, and argue for the viability of an unfamiliar approach that takes the nature of contingency as the core phenomenon that a theory of modality needs to explain. In the fourth part, I explain my methodology and briefly defend the general project of naturalistic metaphysics.

scholarly journals Criteria and Applications of the MK Classification System

1979 ◽  
Vol 47 ◽  
pp. 23-30
Author(s):  
R. F. Garrison
Keyword(s):  
Present State ◽  
Classification System ◽  
Visual Inspection ◽  
Higher Dimensions ◽  
Variable Stars ◽  
Specific Reference ◽  
The Sun ◽  
The Third ◽  
Future Developments ◽  
Inspection Techniques

AbstractA review is given of the present state of MK classification, with a view to future developments in techniques and instrumentation. The principle of the complementarity of quantitative and visual inspection techniques is stressed.Included in the discussion are examples of problems which are currently outstanding. Among these are variable stars, marginal peculiarities, fundamental standards (with specific reference to the Sun), and representation of the third and higher dimensions.

Nonlinear Optics of Linear Conjugated Polymers

1992 ◽  
Vol 247 ◽  
Author(s):  
D. Guo ◽  
S. Mazumdar ◽  
G. I. Stegeman ◽  
M. Cha ◽  
D. Neher ◽  
...  
Keyword(s):  
Conjugated Polymers ◽  
Dipole Moments ◽  
Harmonic Signal ◽  
Oscillator Strengths ◽  
Experimental Investigations ◽  
Transition Dipole ◽  
Third Harmonic ◽  
The Third ◽  
Transition Dipole Moments ◽  
Spectral Ranges

The third order nonlinear optical properties of conjugated polymers have been considered promising since the 1970s when Sauteret et al reported large non-resonant values in PTS.[1] Although it is well-understood that the physical origin of the nonlinearities is due to the delocalization of the π-electrons, the details, and how best to calculate them have been the focus of a continuing theoretical dialogue. Until recently, experimental investigations of nonlinearities have been limited to only a few wavelengths. Now third harmonic generation (THG), which accesses only the electronic nonlinearities, can be performed over wide spectral ranges, for example from 500 to 2000 nm. The resulting third harmonic wavelength typically spans the electronic molecular transitions associated with the nonlinearities. By measuring the spectral distribution of both the amplitude and phase of the third harmonic signal, the dominant transitions (between the“essential states”) contributing to the nonlinearity can be identified. Such information is most useful for comparing with theories in which the oscillator strengths (transition dipole moments) for the various molecular transitions are calculated.

Experimental Investigations Concerning Erosive Aggressiveness of Cavitation at Different Test Configurations

Volume 3 ◽  
2004 ◽  
Author(s):  
B. Bachert ◽  
M. Dular ◽  
S. Baumgarten ◽  
G. Ludwig ◽  
B. Stoffel
Keyword(s):  
Mass Loss ◽  
Cavitation Erosion ◽  
Evaluation Method ◽  
Experimental Investigations ◽  
Cavitating Flows ◽  
Test Rig ◽  
The Third ◽  
Long Duration ◽  
Initial Stage ◽  
Test Objects

The experimental results, which will be presented in this paper, demonstrate the significant influence of the flow velocity, respectively the rotational speed, on the erosive aggressiveness of cavitating flows. On two of the three investigated test objects, cavitation erosion can only be observed in the initial stage by the so-called pit-count evaluation method. Developed erosion with mass loss is impossible to measure because of the very long duration until mass loss appears. The third test rig generates a very aggressive type of cavitation, so that mass loss, depending on the tested material, will appear after relatively short durations. In addition, the initial stage of cavitation erosion can be observed. Three different techniques were applied to investigate cavitation erosion in the initial and developed stage. Thereby, the capability of methods to quantify erosive effects in dependence of influencing operating parameters has been proven.

Lode Dependences for Isotropic Pressure-Sensitive Elastoplastic Materials

1990 ◽  
Vol 57 (3) ◽  
pp. 498-506 ◽  
Author(s):  
J. P. Bardet
Keyword(s):  
Experimental Investigations ◽  
Present Communication ◽  
Modified Model ◽  
True Triaxial ◽  
The Third ◽  
Pressure Sensitive ◽  
Isotropic Pressure ◽  
Elastoplastic Materials ◽  
Lode Angle ◽  
Stress Invariant

Experimental investigations indicate that the third stress invariant; Lode angle α affects significantly the behavior of pressure sensitive materials. The present communication presents a formulation to account for α in isotropic pressure-sensitive elastoplastic materials. Seven Lode dependences are reviewed. A new one, referred to as LMN, in proposed to generalize Lade and Duncan, and Matsuoka and Nakai failure surfaces. The formulation is general enough to introduce α into the isotropic elastoplastic modes which are only developed in terms of first and second-stress invariants. As an illustration, several Lode dependences are introduced into Roscoe and Burland model. The performance of the modified model is estimated by comparing experimental and analytical results in the case of true triaxial loadings on normally consolidated clay.

Snow and Ice Control System Based on Slipperiness Data Transmitted by Drivers: Usefulness of Subjective Slipperiness Data

1996 ◽  
Vol 1533 (1) ◽  
pp. 44-49
Author(s):  
Takashi Nakatsuji ◽  
Takashi Fujiwara ◽  
Toru Hagawara ◽  
Yuki Onodera
Keyword(s):  
Control Systems ◽  
Weather Conditions ◽  
Friction Coefficients ◽  
The Road ◽  
The Third ◽  
Road Surfaces ◽  
Road Condition ◽  
The Relationship ◽  
Ice Control ◽  
Snow And Ice

In Japan, the regulation of studded tires requires the establishment of new countermeasures for effective ice control on slippery roads in winter. The most important information for snow and ice control systems is determining the slipperiness of road surfaces. To detect the slipperiness simply and precisely, a monitoring system was examined in which drivers judged the slipperiness. To evaluate the suitability of such slipperiness data, three investigations were carried out: (a) the relationship between the road condition classification and the slipperiness index, (b) the effectiveness of the subdivision of road classification, and (c) the comparison of slipperiness indexes with the actual friction coefficients. To address the first problem, the road conditions were investigated for 1 month with the cooperation of 10 taxi companies. It was found that the subjective slipperiness index was more sensitive to changes in weather conditions than the road classifications, and that icy roads do not always correspond to slippery roads. That is, there was a limitation on expressing road conditions by road classification. For the second problem, a similar investigation was performed by subdividing the road conditions into more classes. It was concluded that the subdivision of road classification is not so effective in precisely representing the slipperiness of roads. For the third problem, it was clarified that the subjective slipperiness indexes more or less agree with the actual friction coefficients. As for the results, the slipperiness index showed potential for use in snow and ice control systems.

Analyzing Robust Stability of an Interval Control System on the Basis of Vertex Polynomials

2019 ◽  
Vol 20 (5) ◽  
pp. 266-273 ◽  
Author(s):  
S. A. Gayvoronskiy ◽  
T. A. Ezangina ◽  
I. V. Khozhaev ◽  
A. A. Nesenchuk
Keyword(s):  
Control System ◽  
Control Systems ◽  
Characteristic Polynomial ◽  
Robust Stability ◽  
Root Locus ◽  
Phase Equation ◽  
The Third ◽  
Stability Degree ◽  
Polynomial Coefficients ◽  
Interval Extension

In the paper, a characteristic polynomial of an interval control system, whose coefficients are unknown or may vary within certain ranges of values, is considered. Parametric variations cause migration of interval characteristic polynomial roots within their allocation areas, whose borders determine robust stability degree of the interval control system. To estimate a robust stability degree, a projection of a polytope of interval characteristic polynomial coefficients on a complex plane must be examined. However, in order to find a robust stability degree it is enough to examine some vertices of a coefficient polytope and not the whole polytope. To find these vertices, which fully determine a robust stability degree, it is proposed to use a basic phase equation of a root locus method. Considering the requirements to placing allocation areas of system poles an interval extension of expressions for angles included to the phase equation. The set of statements, allowing to find a sum of pole angles intervals in the case of degree of oscillating robust stability, were formulated and proved. From these statements, a set of double interval angular inequalities was derived. The inequalities determine ranges of angles of all root locus edge branches departure from every pole. Considered research resulted in a procedure of finding coordinates of verifying vertices of a coefficients polytope and vertex polynomials according to these vertices. Such polynomials were found for oscillating robust stability degree analysis of interval control systems of the second, the third and the forth order. Also, similar statements were derived for aperiodical robust stability degree analysis. Numerical examples of vertex analysis of oscillating and aperiodical robust stability degree were provided for interval control systems of the second, the third and the fourth order. Obtained results were proved by examining root allocation areas of interval characteristic polynomials examined in application examples of proposed methods.

Experiences with the shikimate-pathway enzymes as targets for rational drug design

2003 ◽  
Vol 31 (3) ◽  
pp. 548-552 ◽  
Author(s):  
J.R. Coggins ◽  
C. Abell ◽  
L.B. Evans ◽  
M. Frederickson ◽  
D.A. Robinson ◽  
...  
Keyword(s):  
Drug Design ◽  
Recent Work ◽  
Present State ◽  
Shikimate Pathway ◽  
Rational Drug Design ◽  
The Third ◽  
Rational Drug ◽  
Current Context ◽  
Anti Fungal

The background and current context of work on the shikimate-pathway enzymes as potential targets for anti-bacterial, anti-fungal and anti-parasitic drugs is reviewed. Recent work on the third enzyme of the pathway, dehydroquinase, which occurs in two structurally and mechanistically distinct forms, is used to illustrate the present state of studies into rational drug design.

Johnsongrass (Sorghum halepense) Control Systems for Field Corn (Zea mays) Utilizing Crop Rotation and Herbicides

1998 ◽  
Vol 12 (4) ◽  
pp. 623-630 ◽  
Author(s):  
Hani Z. Ghosheh ◽  
James M. Chandler
Keyword(s):  
Control Systems ◽  
Growing Season ◽  
Sorghum Halepense ◽  
Agricultural Experiment Station ◽  
The Third ◽  
Net Returns ◽  
Field Corn ◽  
Continuous Corn ◽  
Agricultural Experiment ◽  
Corn Grain

Johnsongrass control systems that included commercially available corn herbicides applied to crop sequences of continuous corn or corn–cotton–corn rotation were evaluated over a 3-yr period at the Texas Agricultural Experiment Station in Burleson County. Herbicide treatments evaluated were EPTC + R-25788 applied preplant incorporated (PPI); metolachlor applied preemergence (PRE); nicosulfuron applied postemergence (POST); and the combination of metolachlor PRE and glyphosate POST applied after corn harvest. Weed control practices applied to plots planted to cotton in the second growing season provided excellent johnsongrass control (≈ 95%). Visual control ratings indicated that nicosulfuron provided the best johnsongrass control (> 80%) among the herbicides evaluated all three years. Metolachlor and glyphosate combinations provided acceptable johnsongrass control the third year of the experiment in both cropping sequences. Corn grain yield and johnsongrass control were best in cotton-rotated plots. The highest returns observed in continuous corn were from either nicosulfuron or the combination of metolachlor and glyphosate. Net returns for all control systems in corn–cotton–corn rotated plots were greater than the weedy check and were equivalent to the lead systems in continuous corn.

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