State of the art of compact optical 3D profile measurement apparatuses: from outer surface to inner surface measurement

2013 ◽  
Author(s):  
Toru Yoshizawa ◽  
Toshitaka Wakayama
Keyword(s):  
Outer Surface ◽  
State Of The Art ◽  
Surface Measurement ◽  
Profile Measurement ◽  
Inner Surface ◽  
3D Profile

ONLINE SURFACE MEASUREMENT WITH DIGITAL SHACK–HARTMANN WAVEFRONT SENSOR

2010 ◽  
Vol 09 (03) ◽  
pp. 123-133
Author(s):  
XIAOMING YIN ◽  
LIPING ZHAO ◽  
XIANG LI ◽  
ZHONGPING FANG
Keyword(s):  
Good Accuracy ◽  
Focal Spot ◽  
Detection Method ◽  
Surface Profile ◽  
Wavefront Sensor ◽  
Surface Measurement ◽  
Profile Measurement ◽  
Practical Applications ◽  
Centroid Detection ◽  
3D Profile

Shack–Hartmann wavefront sensor splits the incident wavefront into many subsections and transfers the distorted wavefront detection into the centroid measurement. The accuracy of the centroid measurement determines the accuracy of the SHWS. In this paper, we have presented an automatic centroid measurement method based on the image processing technology for practical applications of the digital SHWS in surface profile measurement. The method can detect the centroid of each focal spot accurately and robustly by eliminating the influences of various noises. Based on this centroid detection method, we have developed a digital SHWS system which can automatically detect centroids of focal spots, reconstruct the wavefront, and measure the 3D profile of the surface. The experimental results demonstrate that the system has good accuracy, repeatability and compatibility to optical misalignment. The system is suitable for online applications of surface measurement.

A SEM and Light Microscope Study of the Epidermal Leaf Structures of the Carnivorous Plant, Sarracenia purpurea, L.

1971 ◽  
Vol 29 ◽  
pp. 358-359
Author(s):  
B. J. Panessa ◽  
J. F. Gennaro
Keyword(s):  
Methylene Blue ◽  
Toluidine Blue ◽  
Outer Surface ◽  
Microscope Study ◽  
Light Microscope ◽  
Carnivorous Plant ◽  
Sarracenia Purpurea ◽  
Inner Surface

Tissue from the hood and sarcophagus regions were fixed in 6% glutaraldehyde in 1 M.cacodylate buffer and washed in buffer. Tissue for SEM was partially dried, attached to aluminium targets with silver conducting paint, carbon-gold coated(100-500Å), and examined in a Kent Cambridge Stereoscan S4. Tissue for the light microscope was post fixed in 1% aqueous OsO4, dehydrated in acetone (4°C), embedded in Epon 812 and sectioned at ½u on a Sorvall MT 2 ultramicrotome. Cross and longitudinal sections were cut and stained with PAS, 0.5% toluidine blue and 1% azure II-methylene blue. Measurements were made from both SEM and Light micrographs.The tissue had two structurally distinct surfaces, an outer surface with small (225-500 µ) pubescent hairs (12/mm2), numerous stoma (77/mm2), and nectar glands(8/mm2); and an inner surface with large (784-1000 µ)stiff hairs(4/mm2), fewer stoma (46/mm2) and larger, more complex glands(16/mm2), presumably of a digestive nature.

Ultrastructure and development of urediospore ornamentation in Melampsora lini

1971 ◽  
Vol 49 (12) ◽  
pp. 2067-2073 ◽  
Author(s):  
L. J. Littlefield ◽  
C. E. Bracker
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Outer Surface ◽  
Spore Wall ◽  
Wall Material ◽  
Wild Type ◽  
Melampsora Lini ◽  
Inner Surface ◽  
External Position ◽  
Basal Portion

The urediospores of Melampsora lini (Ehrenb.) Lev. are echinulate, with spines ca. 1 μ long over their surface. The spines are electron-transparent, conical projections, with their basal portion embedded in the electron-dense spore wall. The entire spore, including the spines, is covered by a wrinkled pellicle ca. 150–200 Å thick. The spore wall consists of three recognizable layers in addition to the pellicle. Spines form initially as small deposits at the inner surface of the spore wall adjacent to the plasma membrane. Endoplasmic reticulum occurs close to the plasma membrane in localized areas near the base of spines. During development, the spore wall thickens, and the spines increase in size. Centripetal growth of the wall encases the spines in the wall material. The spines progressively assume a more external position in the spore wall and finally reside at the outer surface of the wall. A mutant strain with finely verrucose spores was compared to the wild type. The warts on the surface of the mutant spores are rounded, electron-dense structures ca. 0.2–0.4 μ high, in contrast to spines of the wild type. Their initiation near the inner surface of the spore wall and their eventual placement on the outer surface of the spore are similar to that of spines. The wall is thinner in mutant spores than in wild-type spores.

The Three-Dimensional Surface Topographic Characterisation of Diamond Grinding Wheels

2010 ◽  
Vol 126-128 ◽  
pp. 690-695
Author(s):  
David Lee Butler
Keyword(s):  
Measurement Techniques ◽  
Three Dimensional ◽  
Surface Measurement ◽  
Grinding Wheel ◽  
Profile Measurement ◽  
Detailed Knowledge ◽  
Grinding Wheels ◽  
Diamond Grinding ◽  
Insight Into ◽  
Dimensional Surface

Surface measurement using three-dimensional stylus instruments is a relatively new technique that offers numerous advantages over more traditional profilometry methods. The information generated is, unlike profile measurement, less subjective and more statistical providing additional insight into the surface structure. One application of surface measurement that has encountered problems when using the profilometry method is that of grinding wheel characterisation. The wheel surface texture (topography) and the conditions under which it is generated have a profound effect upon the grinding performance as characterised by the grinding forces, power consumption, temperature, and surface integrity of components. A detailed knowledge of the nature of the topography of the grinding wheel would provide further insight into surface interactions between the wheel and workpiece as well as enabling improved control of the grinding process in general. In this paper four diamond grinding wheels of 91 and 181 micron grit size were subjected to differing dressing conditions to produce varying final wheel topographies. Three-dimensional surface measurement techniques were employed to quantitatively characterise the topographic change and provide an aerial estimation of the number of cutting grains. The results demonstrate that the techniques can distinguish between a worn and dressed wheel. In addition, the parametric values generated from the various surfaces can aid the user in determining when re-dressing is required.

Development of Inverse Analysis of Heat Conduction and Thermal Stress for Elbow: Part I

2013 ◽  
Author(s):  
Seiji Ioka ◽  
Shiro Kubo ◽  
Mayumi Ochi ◽  
Kiminobu Hojo
Keyword(s):  
Heat Conduction ◽  
Thermal Stress ◽  
Transfer Function ◽  
Surface Temperature ◽  
Outer Surface ◽  
Inverse Analysis ◽  
Temperature History ◽  
Analysis Method ◽  
Inner Surface ◽  
Inverse Analysis Method

Thermal fatigue may develop in piping elbow with high temperature stratified flow. To prevent the fatigue damage by stratified flow, it is important to know the distribution of thermal stress and temperature history in a pipe. In this study, heat conduction inverse analysis method for piping elbow was developed to estimate the temperature history and thermal stress distribution on the inner surface from the outer surface temperature history. In the inverse analysis method, the inner surface temperature was estimated by using the transfer function database which interrelates the inner surface temperature with the outer surface temperature. Transfer function database was calculated by FE analysis in advance. For some patterns of the temperature history, inverse analysis simulations were made. It was found that the inner surface temperature history was estimated with high accuracy.

Expansion of the area vasculosa of the chick after removal of the ectoderm

Development ◽  
1970 ◽  
Vol 24 (1) ◽  
pp. 95-108
Author(s):  
J. M. Augustine
Keyword(s):  
Basement Membrane ◽  
Outer Surface ◽  
Chicken Embryo ◽  
Area Vasculosa ◽  
Inner Surface

The role of the ectoderm in the expansion of the mesoderm in the area vasculosa of the chicken embryo was studied. The basement membrane of the ectoderm was found to constitute a substratum for the expansion of both layers of mesoderm, since (a) the somatic mesoderm, particularly at its margin, adheres to the basement membrane, and (b) the somatic and splanchnic mesoderm adhere to each other throughout most of the area opaca. Following removal of the ectoderm from the outer surface of the basement membrane, movement of the underlying mesoderm along its inner surface stopped. Mean expansion of the mesoderm in these cases was zero. Following removal of both ectoderm and basement membrane, expansion of the underlying mesoderm was normal in amount. Experimental changes in the ectodermal substratum can thus stop movement of the associated mesoderm, but the role which the substratum normally plays in mesodermal expansion remains unclear.

A weighted fusion method with multi-system for improving measurement accuracy of structured light 3D profilometry

2021 ◽  
Author(s):  
Chao Xing ◽  
Junhui Huang ◽  
Zhao Wang ◽  
Jianmin Gao
Keyword(s):  
Measurement Errors ◽  
Measurement Accuracy ◽  
Structured Light ◽  
Profile Measurement ◽  
Complex Surfaces ◽  
3D Profilometry ◽  
Weighted Fusion ◽  
Multiple Measurements ◽  
Geometric Relationship ◽  
3D Profile

Abstract It is a challenge to improve the accuracy of 3D profile measurement based on binary coded structured light for complex surfaces. A new method of weighted fusion with multi-system is presented to reduce the measurement errors due to the stripe grayscale asymmetry, which is based on the analysis of stripe center deviation related to surface normal and the directions of incident and reflected rays. First, the stripe center deviation model is established according to the geometric relationship between the stripe center deviation, the incident and reflected angles at any measured point. The influence of each variable on stripe center deviation is analyzed, and three subsystems are formed by a binocular structured light framework to achieve multiple measurements based on the influence regularity. Then in order to improve the measurement accuracy, different weights are assigned to the measured point in different subsystems according to the stripe center deviation model and its relationship with measurement error, and the weighted data from different subsystems are fused. Experiments are carried out to validate the presented method, and the experimental results demonstrate that it effectively improves the measurement accuracy of complex surfaces and measurement accuracy is improved by about 27% compared with the conventional method.

Parametric Study of Dry Sliding Wear Behaviour of Functionally Graded Al LM25/Si3N4 Composite by Response Surface Methodology

2015 ◽  
Vol 24 (6) ◽  
pp. 096369351502400 ◽  
Author(s):  
N. Radhika ◽  
R. Raghu
Keyword(s):  
Response Surface Methodology ◽  
Wear Rate ◽  
Response Surface ◽  
Outer Surface ◽  
Sliding Wear ◽  
Centrifugal Casting ◽  
Functionally Graded ◽  
Wear Behaviour ◽  
Inner Surface ◽  
Sliding Distance

Functionally graded aluminium LM25/silicon nitride composite was produced through stir casting followed by centrifugal casting and obtained a hollow cylindrical cast component with dimensions of 150 × 150 × 20 mm. The microstructural examination and the hardness test were carried out on the outer (1 mm) and inner surface (17 mm) as the function of radial distance from the outer periphery. The outer surface was observed with particle enriched region compared to inner surface and exhibited higher hardness. Hence the outer surface of the functionally graded composite was only further subjected to sliding wear test in pin-on-disc tribometer. The Central Composite Design in Response Surface Methodology was used to design the experiments for the selected parameters such as load (15–45 N), velocity (0.5–2.5 m/s) and sliding distance (500–2000 m). Regression test and Analysis of Variance were conducted to check the adequacy of the constructed model. The surface plots for wear rate showed that wear rate increased with increase in load and non-linearly varied with increase in velocity and sliding distance. Scanning Electron Microscopy analysis was conducted on the worn-out surfaces and observed mild to severe wear transition on increase of load.

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