Parametric-Based Determination of Cylindrical Variations in Geometric Tolerancing

1999 ◽  
Vol 122 (3) ◽  
pp. 549-555 ◽  
Author(s):  
C. Carolina Ba´rcenas ◽  
Paul M. Griffin

The ANSI Y14.5M Geometric Dimensioning and Tolerancing Standards have been used for many years by practitioners for size and form verification of manufactured parts. However, different parts may satisfy these tolerances and yet perform quite differently because of surface variations not specified in the standards. We present a statistically-based technique for the determination of the type of surface variation for cylindrical parts. This technique is based on a parametric-based part representation used for fitting. The method is illustrated with examples. [S1087-1357(00)00403-2]

Author(s):  
Jhy-Cherng Tsai ◽  
Jing-Sheng Chang

Abstract Geometric tolerancing is an important factor affecting the functional performance and manufacturing cost of a product. Tolerancing specifications have to be assigned with care at design time to reduce the gap between design and manufacturing. This paper describes a system that simplifies tolerancing assignment and uses dimensioning and tolerancing data for related applications. The system consists of five modules for feature type classification, tolerance assignment, tolerance network construction, frame transformation, and tolerance analysis interface. It provides an interactive interface for tolerance assignment based on geometric features that a designer can select from decomposed isometric drawing. The system also recognizes the type of a feature so that only appropriate tolerancing specifications can be assigned. Geometric dimensioning and tolerancing data are used to construct a network for representing the tolerancing and mating relationship among features. The network is then converted for tolerance analysis via a tolerance analysis interface.


2013 ◽  
Vol 42 (12) ◽  
pp. 2082-2087 ◽  
Author(s):  
Young-Hyun Kim ◽  
Da-Bin Bae ◽  
Jong Seok Lee ◽  
Sun-Ok Park ◽  
Sang-Jong Lee ◽  
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Keyword(s):  

2019 ◽  
Vol 32 ◽  
pp. 302-319
Author(s):  
Khadeeja S.J. Al-Husseiny ◽  
Maryam T. Khrebish

The current study aimed to estimate the pigments of some muscles parts taken from cows, sheep and chicken (thigh, chest and back). The chemical content including moisture, protein, lipids and ash, as well as the pH and the water holding capacity have been evaluated. Results showed that the moisture differed among three animals with high percentage of moisture, ash and lipid in back in compared with other parts of cows. while significant difference in the percentage of ash of back with other parts and in protein in chest with other parts of sheep. The significant differences were recorded in percentage of ash of three parts of chicken, also significant differences between chest and back. The water holding capacity of fresh meat samples taken from thigh, chest and back of cows, sheep and chicken significantly differ among samples. pH values which reflect a confect in water holding capacity of meat samples taken from different parts of the body and from different animal. In addition, there was a significant differences in the percentage of the presences of myoglobin, metmyoglobin and oxymyoglobin in different samples taken from different parts of the slaughtered animals.


2021 ◽  
Author(s):  
Suciu Felicia ◽  
Roșca Adrian Cosmin ◽  
Lupu Carmen ◽  
Popescu Antoanela ◽  
Badea Victoria

"The history of medicinal plants is associated with the evolution of civilization. In all regions of the world, the history of nations shows that these plants have always occupied an important place in medicine, in cosmetic products, and culinary preparations. The paper aims to determine the total polyphenols in different parts of the species Lysimachia nummularia L. In our study, we focused on the extraction of polyphenolic compounds in different solvents. The solvents used in the extraction were: 40% ethanol, concentrated methanol, in water. The total polyphenol content was determined by spectrophotometric methods, a method from the European Pharmacopoeia 10.0, with minor modifications. The total polyphenol content of different extracts varied depending on the extraction process. Different parts of the plant and different solvents were used in the determinations carried out to establish the optimal extraction method for the organs of Lysimachia nummularia L."


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