Arago-Poisson diffraction spot observed in the shadow area of an axicon lens

2015 ◽  
Vol 44 (4) ◽  
pp. 391-396 ◽  
Author(s):  
Guolu Ma ◽  
Guoying Zeng ◽  
Bin Zhao
Keyword(s):  
Diffraction Spot ◽  
Shadow Area

Poisson Diffraction Spot Generated in Shadow Area of Axicon

2014 ◽  
Vol 34 (4) ◽  
pp. 0405001
Author(s):  
马国鹭 Ma Guolu ◽  
赵斌 Zhao Bin
Keyword(s):  
Diffraction Spot ◽  
Shadow Area

Convergent Beam Electron Diffraction

1978 ◽  
Vol 36 (3) ◽  
pp. 304-315
Author(s):  
G. Lehmpfuhl
Keyword(s):  
Electron Diffraction ◽  
Diffraction Pattern ◽  
Crystal Surface ◽  
Diffraction Spot ◽  
Crystal Thickness ◽  
Large Area ◽  
Electron Microscopic ◽  
Additional Information ◽  
Microscopic Investigations

Introduction In electron microscopic investigations of crystalline specimens the direct observation of the electron diffraction pattern gives additional information about the specimen. The quality of this information depends on the quality of the crystals or the crystal area contributing to the diffraction pattern. By selected area diffraction in a conventional electron microscope, specimen areas as small as 1 µ in diameter can be investigated. It is well known that crystal areas of that size which must be thin enough (in the order of 1000 Å) for electron microscopic investigations are normally somewhat distorted by bending, or they are not homogeneous. Furthermore, the crystal surface is not well defined over such a large area. These are facts which cause reduction of information in the diffraction pattern. The intensity of a diffraction spot, for example, depends on the crystal thickness. If the thickness is not uniform over the investigated area, one observes an averaged intensity, so that the intensity distribution in the diffraction pattern cannot be used for an analysis unless additional information is available.

The Shadow Widths of Very Small Particles are Formed Independently of the Metal Cap Build Up on the Particle

1981 ◽  
Vol 39 ◽  
pp. 568-569
Author(s):  
George C. Ruben
Keyword(s):  
Gold Particle ◽  
Film Surface ◽  
Small Particles ◽  
Geometric Process ◽  
Metal Free ◽  
Shadow Area

The formation of shadows behind small particles has been thought to be a geometric process (GP) where the metal cap build up on the particle creates a shadow width the same size as or larger than the particle. This GP cannot explain why gold particle shadow widths are generally larger than the gold particle and may have no appreciable metal cap build up (fig. 1). Ruben and Telford have suggested that particle shadow widths are formed by the width dependent deflection of shadow metal (SM) lateral to and infront of the particle. The trajectory of the deflected SM is determined by the incoming shadow angle (45°). Since there can be up to 1.4 times (at 45°) more SM directly striking the particle than the film surface, a ridge of metal nuclei lateral to and infront of the particle can be formed. This ridge in turn can prevent some SM from directly landing in the metal free shadow area. However, the SM that does land in the shadow area (not blocked by the particle or its ridge) does not stick and apparently surface migrates into the SM film behind the particle.

scholarly journals Multiband Printed Loop Mobile Phone Antenna for LTE/WWAN/GNSS Application

2016 ◽  
Vol 2016 ◽  
pp. 1-7
Author(s):  
Yuan Xu ◽  
Hao-Miao Zhou
Keyword(s):  
Mobile Phone ◽  
Smartphone Application ◽  
Satellite System ◽  
Circuit Board ◽  
Navigation Systems ◽  
Lumped Element ◽  
Shadow Area ◽  
Redundant Design ◽  
Resonant Modes ◽  
Global Navigation Satellite

A multiband printed loop mobile phone antenna for LTE/WWAN/GNSS application is presented. It covers seven communication bands (VSWR < 3) and GNSS band (VSWR < 1.5). The so-called GNSS (global navigation satellite system) band includes COMPASS, GALILEO, GPS, and GLONASS. From the analysis of the structure, the coupled-fed antenna mainly consists of three parts: the feeding strip, shorted strip, and U-shaped parasitic coupling strip. The proposed antenna works in three resonant modes, respectively, at 860 MHz (0.25λ), 1620 MHz (0.5λ), and 2620 MHz (1λ). A solution is provided, by which the navigation antenna can be integrated into the communication main antenna to save space. The antenna not only can work in GSM850/900/1800/1900/UMTS2100/LTE2300/2500 bands but also covers the world’s four major navigation systems. Moreover, the proposed antenna can be easily printed on the circuit board without loading any lumped element and only occupies a small volume of 18 × 32 × 3 mm3, which is suitable for smartphone application. In addition, the redundant design of multinavigation system is quite favorable for the elimination of errors or shadow area caused by single navigation system, especially for outdoor investigation, national security, and so on.

Nipple Localization in Automated Whole Breast Ultrasound Coronal Scans Using Ensemble Learning

2020 ◽  
Vol 43 (1) ◽  
pp. 29-45
Author(s):  
Alex Noel Joseph Raj ◽  
Ruban Nersisson ◽  
Vijayalakshmi G. V. Mahesh ◽  
Zhemin Zhuang
Keyword(s):  
Texture Features ◽  
Breast Ultrasound ◽  
Support Vector ◽  
Ultrasound Images ◽  
Shadow Area ◽  
Hu Moments ◽  
Artificial Neural Network Ann ◽  
Cade System ◽  
Occurrence Matrix ◽  
Shape Complexity

Nipple is a vital landmark in the breast lesion diagnosis. Although there are advanced computer-aided detection (CADe) systems for nipple detection in breast mediolateral oblique (MLO) views of mammogram images, few academic works address the coronal views of breast ultrasound (BUS) images. This paper addresses a novel CADe system to locate the Nipple Shadow Area (NSA) in ultrasound images. Here the Hu Moments and Gray-level Co-occurrence Matrix (GLCM) were calculated through an iterative sliding window for the extraction of shape and texture features. These features are then concatenated and fed into an Artificial Neural Network (ANN) to obtain probable NSA’s. Later, contour features, such as shape complexity through fractal dimension, edge distance from the periphery and contour area, were computed and passed into a Support Vector Machine (SVM) to identify the accurate NSA in each case. The coronal plane BUS dataset is built upon our own, which consists of 64 images from 13 patients. The test results show that the proposed CADe system achieves 91.99% accuracy, 97.55% specificity, 82.46% sensitivity and 88% F-score on our dataset.

scholarly journals Microchannel Fabrication Using A Photo-Patternable Adhesive Material for Recording Conformational Changes of KcsA Channel with the Diffracted X-ray Tracking Method

Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 972 ◽  
Author(s):  
Yoshikazu Hirai ◽  
Yasuaki Mori ◽  
Tomoki Tabuchi ◽  
Hirofumi Shimizu ◽  
Toshiyuki Tsuchiya ◽  
...  
Keyword(s):  
Conformational Changes ◽  
Diffraction Spot ◽  
High Resolution Imaging ◽  
Potassium Ion Channel ◽  
Adhesive Material ◽  
Tracking Method ◽  
X Ray ◽  
Sin Membrane ◽  
Resolution Imaging ◽  
Gold Nanocrystal

Diffracted X-ray tracking (DXT) method can trace conformational changes of KcsA potassium ion channel during gating by recording position of diffraction spot from a gold nanocrystal attached to the channel as a movie. For high-resolution imaging under controlled microenvironments for KcsA channels, we report a microfluidic device consisting of two SiN membrane windows bonded with a photo patternable adhesive material. The reduced signal-to-background ratio as well as suitable adhesive material thickness for the microchannel are discussed in the experiment at the synchrotron radiation facility.

scholarly journals ANALYZING SPECTRAL CHARACTERISTICS OF SHADOW AREA FROM ADS-40 HIGH RADIOMETRIC RESOLUTION AERIAL IMAGES

2016 ◽  
Vol XLI-B7 ◽  
pp. 223-227 ◽  
Author(s):  
Yi-Ta Hsieh ◽  
Shou-Tsung Wu ◽  
Chaur-Tzuhn Chen ◽  
Jan-Chang Chen
Keyword(s):  
Remote Sensing ◽  
Land Cover ◽  
Vegetation Index ◽  
Spectral Characteristics ◽  
Aerial Images ◽  
Aerial Image ◽  
Optical Remote Sensing ◽  
Shadow Area ◽  
Vegetation Indexes ◽  
Research Findings

The shadows in optical remote sensing images are regarded as image nuisances in numerous applications. The classification and interpretation of shadow area in a remote sensing image are a challenge, because of the reduction or total loss of spectral information in those areas. In recent years, airborne multispectral aerial image devices have been developed 12-bit or higher radiometric resolution data, including Leica ADS-40, Intergraph DMC. The increased radiometric resolution of digital imagery provides more radiometric details of potential use in classification or interpretation of land cover of shadow areas. Therefore, the objectives of this study are to analyze the spectral properties of the land cover in the shadow areas by ADS-40 high radiometric resolution aerial images, and to investigate the spectral and vegetation index differences between the various shadow and non-shadow land covers. According to research findings of spectral analysis of ADS-40 image: (i) The DN values in shadow area are much lower than in nonshadow area; (ii) DN values received from shadowed areas that will also be affected by different land cover, and it shows the possibility of land cover property retrieval as in nonshadow area; (iii) The DN values received from shadowed regions decrease in the visible band from short to long wavelengths due to scattering; (iv) The shadow area NIR of vegetation category also shows a strong reflection; (v) Generally, vegetation indexes (NDVI) still have utility to classify the vegetation and non-vegetation in shadow area. The spectral data of high radiometric resolution images (ADS-40) is potential for the extract land cover information of shadow areas.

EXTRAX: anImageJplug-in for electron diffraction intensity extraction

2009 ◽  
Vol 43 (1) ◽  
pp. 191-195 ◽  
Author(s):  
V. Dorcet ◽  
X. Larose ◽  
C. Fermin ◽  
M. Bissey ◽  
P. Boullay
Keyword(s):  
Image Processing ◽  
Electron Diffraction ◽  
Public Domain ◽  
High Order ◽  
Diffraction Spot ◽  
Two Dimensional ◽  
Diffraction Intensity ◽  
Dimensional Lattice ◽  
Peak Location ◽  
Modulation Vector

A plug-in (EXTRAX) has been developed forImageJ– a public domain Java-based program widely used for image processing and analysis in microscopy. This plug-in allows the extraction and measurement of intensities from electron diffraction spot patterns with a semi-automatic peak location based on a two-dimensional lattice given by the user. It is also possible to take into account supplementary spots originating from high-order Laue zones and/or the existence of a modulation vector.

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