Development of a high-sensitivity array detector and fast digital data analysis system for coherent nanodiffractlon patterns

1989 ◽  
Vol 47 ◽  
pp. 496-497
Author(s):  
J. H. Butler ◽  
G. Y. Fan ◽  
J. M. Cowley ◽  
P. Rez
Keyword(s):  
Small Diameter ◽  
Region Of Interest ◽  
High Sensitivity ◽  
Digital Data ◽  
Computer Hardware ◽  
Array Detector ◽  
Technological Advances ◽  
Array Detectors ◽  
Analysis System ◽  
Data Analysis System

The spatial limits of conventional narrow beam analytical methods (XRD, SAD and CBED) are still large compared with the microstructural features which govern the properties of many materials. Recent technological advances in computer hardware and sensitive electron array detectors have made it feasible to examine the structure of subnanometer crystal volumes. By placing an extremely small diameter, coherent electron probe over the region of interest and digitally comparing the resultant 'nanodiffraction' pattern to a computer generated pattern which is based on dynamical diffraction in a model structure, it is possible to ascertain the local structure with a minimum of the subjectivity which is inherent in conventional operator interpretations of electron scattering intensities. This is especially important when very small beam diameters are involved, as the diffraction intensities are strongly dependent on crystal tilt and thickness, as well as the position of the beam relative to the unit cell origin.

Direct Measurement of Electron Drift Parameters using Depth Sensing Single Carrier CdZnTe Detectors

1997 ◽  
Vol 487 ◽  
Author(s):  
Z. He ◽  
G. F. Knoll ◽  
D. K. Wehe ◽  
Y. F. Du
Keyword(s):  
Drift Time ◽  
Wide Band ◽  
High Energy ◽  
Digital Data ◽  
Depth Sensing ◽  
Single Carrier ◽  
Analysis System ◽  
Cdznte Detectors ◽  
Data Analysis System ◽  
Carrier Charge

AbstractThis paper describes some novel techniques developed for directly measuring the electron mobility μe and mean free drift time Te in wide band gap semiconductors. These methods are based on a newly-developed digital data analysis system, in conjunction with single carrier charge sensing and depth sensing techniques. Compared with conventional methods, the new techniques are easier to implement, do not involve curve fitting, allow the use of high energy γ-rays and are not sensitive to variations in pulse rise time.

scholarly journals X-Ray Fluorescence Analysis Applied to Small Samples

1977 ◽  
Vol 21 ◽  
pp. 171-185 ◽  
Author(s):  
J.M. Jaklevic ◽  
W.R. French ◽  
T.W. Clarkson ◽  
M.R. Greenwood
Keyword(s):  
Small Diameter ◽  
Fluorescence Analysis ◽  
High Sensitivity ◽  
Sample Volume ◽  
Small Sample ◽  
Small Samples ◽  
X Ray ◽  
Hair Samples ◽  
Fine Focus ◽  
Analysis System

We describe an adaptation of photon excited x-ray fluorescence analysis which is optimized for the analysis of small samples. A fine focus x-ray tube is used in conjunction with small diameter detector collimators in order to focus on a small sample volume with as high sensitivity as possible. Sample areas of less than 1 mm diameter can be analyzed with ppm detectability. In applications involving the analysis of human hair samples, a minimum detectable limit of 10 ppm Hg can be realized in a 1 mm long segment of a single hair in a counting time of 200 seconds. Simultaneous measurements of the sample mass can be obtained from the intensity of the incoherent scattering. An automated x-ray fluorescence analysis system using the technique for the scanning of elemental profiles in such hair samples will be described.

Developmental Measurement of Mental Attention

1994 ◽  
Vol 17 (1) ◽  
pp. 161-200 ◽  
Author(s):  
Juan Pascual-Leone ◽  
Raymond Baillargeon
Keyword(s):  
Latent Class ◽  
Latent Class Models ◽  
Categorical Data Analysis ◽  
Test Items ◽  
Mental Demand ◽  
Mental Attention ◽  
Constructivist Model ◽  
Discrete Manner ◽  
Analysis System ◽  
Data Analysis System

A dialectical constructivist model of mental attention ("effort") and of working memory is briefly presented, and used to explicate subjects' processing in misleading test items. We illustrate with task analyses of the Figural Intersections Test (FIT). We semantically derive a set of 10 Theoretical Structural Predictions (TSP) that stipulate relations between mental attentional resources (mental-power: Mp) and the systematically varied mental demand of items (mental-demand: Md), as they jointly codetermine probable performance (conditional probabilities of passing and failing). These predictions are evaluated on first approximation using a known family of ordered Latent Class models, all probabilistic versions of Guttman's unidimensional scale. Parameters of these models were estimated using the Categorical Data Analysis System of Eliason (1990). Main results are: (1) Data fit Lazarsfeld's latent-distance model, providing initial support for our 10 predictions; (2) The M-power of children (latent Mp-classes) when assessed behaviourally may increase with age in a discrete manner, and have the potential to generate interval scales of measurement; (3) In the light of our results what statisticians often consider "error of measurement" appears (in part) to be signal, not noise: The organismic signal of misleading (Y-) processes that in their dialectical (trade-off) interaction with success-producing (X-) processes generate performance.

scholarly journals Tin Disulfide-Coated Microfiber for Humidity Sensing with Fast Response and High Sensitivity

Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 648
Author(s):  
Aijie Liang ◽  
Jingyuan Ming ◽  
Wenguo Zhu ◽  
Heyuan Guan ◽  
Xinyang Han ◽  
...  
Keyword(s):  
Humidity Sensor ◽  
Small Diameter ◽  
High Sensitivity ◽  
Large Change ◽  
Small Variation ◽  
Response Speed ◽  
Fast Response ◽  
Tin Disulfide ◽  
Recovery Times ◽  
Response And Recovery

Breath monitoring is significant in assessing human body conditions, such as cardiac and pulmonary symptoms. Optical fiber-based sensors have attracted much attention since they are immune to electromagnetic radiation, thus are safe for patients. Here, a microfiber (MF) humidity sensor is fabricated by coating tin disulfide (SnS2) nanosheets onto the surface of MF. The small diameter (~8 μm) and the long length (~5 mm) of the MF promise strong interaction between guiding light and SnS2. Thus, a small variation in the relative humidity (RH) will lead to a large change in optical transmitted power. A high RH sensitivity of 0.57 dB/%RH is therefore achieved. The response and recovery times are estimated to be 0.08 and 0.28 s, respectively. The high sensitivity and fast response speed enable our SnS2-MF sensor to monitor human breath in real time.

Three Dimensional Video Imaging for Endoscopic Sinus Surgery and Diagnosis

1995 ◽  
Vol 9 (4) ◽  
pp. 197-202 ◽  
Author(s):  
Anthony J. Reino ◽  
William Lawson ◽  
Baxter J. Garcia ◽  
Robert J. Greenstein
Keyword(s):  
Endoscopic Sinus Surgery ◽  
Three Dimensional ◽  
Small Diameter ◽  
Image Distortion ◽  
Sinus Surgery ◽  
Depth Of Field ◽  
Visual Fatigue ◽  
Video Imaging ◽  
Video Cameras ◽  
Technological Advances

Technological advances in video imaging over the last decade have resulted in remarkable additions to the armamentarium of instrumentation for the otolaryngologist. The use of video cameras and computer generated imaging in the operating room and office is invaluable for documentation and teaching purposes. Despite the obvious advantages of these systems, problems are evident, the most serious of which include image distortion and inability to judge depth of field. For more than 6 decades 3D imaging has been neither technically nor commercially successful. Reasons include alignment difficulties and image distortion. The result is “visual fatigue,” usually in about 15 minutes. At its extreme, this may be characterized by headache, nausea, and even vomiting. In this study, we employed the first 3D video imager to electronically manipulate a single video source to produce 3D images; therefore, neither alignment nor image distortions were produced. Of interest to the clinical surgeon, “visual fatigue” does not seem to occur; however, with prolonged procedures (greater than 2 hours) there exists the potential for physical intolerance for some individuals. This is the first unit that is compatible with any rigid or flexible videoendoscopic system and the small diameter endoscopes available for endoscopic sinus surgery. Moreover, prerecorded 2D tapes may be viewed in 3D on an existing VCR. The 3D image seems to provide enhanced anatomic awareness with less image distortion. We have found this system to be optically superior to the 2D video imagers currently available.

scholarly journals X-ray transmission grating spectrometer with CCD detector for laser plasma studies

1991 ◽  
Vol 9 (2) ◽  
pp. 579-591 ◽  
Author(s):  
L. Pína ◽  
H. Fiedorowicz ◽  
M. O. Koshevoi ◽  
A. A. Rupasov ◽  
B. Rus ◽  
...  
Keyword(s):  
Laser Plasma ◽  
Dynamic Range ◽  
High Sensitivity ◽  
Array Detector ◽  
Charge Coupled Device ◽  
X Ray ◽  
Transmission Grating ◽  
Hot Plasma ◽  
Ccd Detector ◽  
Wet Processing

A program is under way to develop methods and instrumentation based on charge-coupled device (CCD) sensors for hot plasma diagnostics. We have developed a new X-ray spectrometer in which a freestanding X-ray transmission grating is coupled to a CCD linear array detector with electronic digitized readout replacing film and its wet processing. This instrument measures time-integrated pulsed X-ray spectra with moderate spectral resolution (δλ ≤ 0.6 nm) over a broad spectral range (0.3–2 keV) with high sensitivity, linearity, and large dynamic range. The performance of the device was tested using laser plasma as the X-ray source.

Integrated diagnostic and data analysis system of the C-2W advanced beam-driven field-reversed configuration plasma experiment

2018 ◽  
Vol 89 (10) ◽  
pp. 10K114 ◽  
Author(s):  
M. C. Thompson ◽  
T. M. Schindler ◽  
R. Mendoza ◽  
H. Gota ◽  
S. Putvinski ◽  
...  
Keyword(s):  
Data Analysis ◽  
Field Reversed Configuration ◽  
Plasma Experiment ◽  
Analysis System ◽  
Data Analysis System
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