Application of the Theory of Envelope to the Determination of Camoid Profiles With Translating Followers

1994 ◽  
Vol 116 (1) ◽  
pp. 320-325 ◽  
Author(s):  
Der Min Tsay ◽  
Guan Shyong Hwang

A new, simple procedure employing the theory of envelope for a family of surfaces with two independent parameters to determine the profiles of camoids with translating spherical followers is presented. Given the follower motion program, the method enables the kinematic relationship for the camoid surface coordinates to be easily generated in an analytical expression. The results are then compared to those obtained by utilizing the principle of contact point between the camoid and the follower surfaces. The pressure angle is analyzed, and the cutter paths required in the machining process are also produced. A numerical example is given to illustrate the application of the approach.

Author(s):  
Der Min Tsay ◽  
Guan Shyong Hwang

Abstract A new, simple procedure employing the theory of envelope for a family of surfaces with two independent parameters to determine the profiles of camoids with translating spherical followers is presented. Given the follower motion program, the method enables the camoid surface coordinates to be easily generated in an analytical expression. The results are then compared to those obtained by utilizing the principle of contact point between the camoid and the follower surfaces. The pressure angle is analyzed, and the cutter paths required in the machining process are also produced. A numerical example is given to illustrate the application of the approach.


1994 ◽  
Vol 116 (3) ◽  
pp. 355-362 ◽  
Author(s):  
Der Min Tsay ◽  
Guan Shyong Hwang

A simple procedure, that can be used to determine the complicated camoid profile with an oscillating spherical follower and to decide the cutter path with the predictable surface roughness, is presented. In the profile design stage, it employs the theory of envelope for a family of surfaces with two independent parameters to derive the camoid contour. Also, the pressure angle is investigated by means of the analytical expression of the camoid. The results are compared to those obtained by using the principle of contact point between the camoid and the follower. Based on the chordal deviation and the scallop height, the surface roughness is analyzed in the machining process. An example is given to illustrate the application of the proposed method.


2004 ◽  
Vol 126 (1) ◽  
pp. 143-147 ◽  
Author(s):  
Anirvan DasGupta ◽  
Amitabha Ghosh

The problem of determination of basic dimensions from the point of view of follower jamming of a cam with translating roller-follower is addressed. Departing from the common practice of using only a constant pressure angle to assess jamming of the follower in its guide, this paper presents a detailed analysis of the problem taking into consideration the follower-guide friction. This leads to new bounds on the pressure angle. Based on the bounds obtained, a graphical method for determination of the optimal values of the basic dimensions is proposed. A numerical example is presented for the purpose of illustration.


2006 ◽  
Vol 61 (5-6) ◽  
pp. 341-346 ◽  
Author(s):  
Jae-Woo Park ◽  
A. M. Abd El-Aty ◽  
Myoung-Heon Lee ◽  
Sung-Ok Song ◽  
Jae-Han Shim

A multiresidue method for the simultaneous determination of 22 organochlorine (OCs) and organophosphorus (Ops) pesticides (including isomers and metabolites), representing a wide range of physicochemical properties, was developed in fatty matrices extracted from meat. Pesticides were extracted from samples with acetonitrile/n-hexane (v :v, 1:1). The analytical screening was performed by gas chromatography coupled with electron-capture detection (ECD). The identification of compounds was based on their retention time and on comparison of the primary and secondary ions. The optimized method was validated by determining accuracy (recovery percentages), precision (repeatability and reproducibility), and sensitivity (detection and quantitation limits) from analyses of samples fortified at 38 to 300 ng/g levels. Correlation coefficients for the 22 extracted pesticide standard curves (linear regression analysis, n = 3) ranged from 0.998 to 1.000. Recovery studies from 2 g samples fortified at 3 levels demonstrated that the GC-ECD method provides 64.4-96.0% recovery for all pesticides except 2,4′-DDE (44.6-50.4%), 4,4′-DDE (51.1-57.5%) and 2,4′-DDT (50.0-51.2%). Both repeatability and reproducibility relative standard deviation values were < 20% for all residues. Detection limits ranged from 0.31 to 1.27 ng/g and quantification limits were between 1.04 and 4.25 ng/g. The proposed analytical method may be used as a simple procedure in routine determinations of OCs and Ops in meat. It can also be applied to the determination of pesticide multi-residues in other animal products such as butter and milk.


2016 ◽  
Vol 686 ◽  
pp. 39-44 ◽  
Author(s):  
Józef Gawlik ◽  
Joanna Krajewska-Śpiewak ◽  
Wojciech Zębala

The chip-forming precision machining process plays a significant role in the mechanical technology. In planning of machining operation, it is crucial to supply the information about the possible minimal value of the machining allowance. For the technologist, when planning the machining operation, it is important to define the minimal thickness of cutting layer correctly. This article presents a new method of describing the start of decohesion process in a workpiece, meaning the determination of the minimal thickness of cutting layer based on the AE signal generated in the cutting zone. The research conducted on the turning of an alloy steel and the analysis of the AE signal strength confirmed that the proposed method opens new possibilities in quickening the identification of the minimal thickness of cutting layer under normal machining conditions.


1988 ◽  
Vol 55 (4) ◽  
pp. 585-596 ◽  
Author(s):  
Anna Polychroniadou

SummaryA simple, rapid and sensitive spectrophotometric assay was developed and evaluated for monitoring proteolysis during cheese ripening, based on the fact that α-amino groups released by hydrolysis of cheese proteins react with trinitrobenzenesulphonic acid to form products that absorb strongly at 420 nm. A linear relationship was shown to exist between A420 and concentration of free α amino groups up to 0·5 HIM (r = 0·999, 38 df, P < 0·001). Repeatability of the method was satisfactory. The coefficient of variance was 0·53% for amino acid solutions and 1·19% for cheese extracts. Average recovery of glycine added to the cheese was 104 ± 2·9%. A comparison of the above method with that of determination of water-soluble N to total N ratio showed that there was good agreement between these two methods of assessment of proteolysis in cheese (r = 0·857, 32 df, P < 0·001). Mainly Feta and Teleme cheese were examined, but a similar correlation was obtained with hard Greek cheeses. Analytical conditions of the procedure are discussed.


2018 ◽  
Vol 64 (1) ◽  
pp. 72 ◽  
Author(s):  
D. Estrada-Wiese ◽  
J.A. Del Río

There are two main physical properties needed to fabricate 1D photonic structures and form perfect photonic bandgaps: the quality of thethickness periodicity and the refractive index of their components. Porous silicon (PS) is a nano-structured material widely used to prepare 1Dphotonic crystals due to the ease of tuning its porosity and its refractive index by changing the fabrication conditions. Since the morphologyof PS changes with porosity, the determination of PS’s refractive index is no easy task. To find the optical properties of PS we can usedifferent effective medium approximations (EMA). In this work we propose a method to evaluate the performance of the refractive index ofPS layers to build photonic Bragg reflectors. Through a quality factor we measure the agreement between theory and experiment and thereinpropose a simple procedure to determine the usability of the refractive indices. We test the obtained refractive indices in more complicatedstructures, such as a broadband Vis-NIR mirror, and by means of a Merit function we find a good agreement between theory and experiment.With this study we have proposed quantitative parameters to evaluate the refractive index for PS Bragg reflectors. This procedure could havean impact on the design and fabrication of 1D photonic structures for different applications.


Sign in / Sign up

Export Citation Format

Share Document