Interactive multiple area spectrum integration (MASI)

1994 ◽  
Vol 52 ◽  
pp. 942-943
Author(s):  
John A. Hunt ◽  
Richard D. Leapman ◽  
David B. Williams
Keyword(s):  
Image Processing ◽  
Low Dose ◽  
Routine Analysis ◽  
Reference Image ◽  
Area Spectrum ◽  
List Type ◽  
Type Number ◽  
Image Processor ◽  
X Ray ◽  
Scanning Path

Interactive MASI involves controlling the raster of a STEM or SEM probe to areas predefined byan integration mask which is formed by image processing, drawing or selecting regions manually. EELS, x-ray, or other spectra are then acquired while the probe is scanning over the areas defined by the integration mask. The technique has several advantages: (1) Low-dose spectra can be acquired by averaging the dose over a great many similar features. (2) MASI can eliminate the risks of spatial under- or over-sampling of multiple, complicated, and irregularly shaped objects. (3) MASI is an extremely rapid and convenient way to record spectra for routine analysis. The technique is performed as follows:Acquire reference imageOptionally blank beam for beam-sensitive specimensUse image processor to select integration mask from reference imageCalculate scanning path for probeUnblank probe (if blanked)Correct for specimen drift since reference image acquisition

Development of imaging plate system for a TEM

1989 ◽  
Vol 47 ◽  
pp. 102-103
Author(s):  
T. Oikawa ◽  
N. Mori ◽  
R. Ichikawa ◽  
M. Ohnishi ◽  
M. Kawasaki
Keyword(s):  
Block Diagram ◽  
Repeated Exposure ◽  
Imaging Plate ◽  
List Type ◽  
Type Number ◽  
Image Processor ◽  
X Ray ◽  
Image Recording ◽  
Application Data ◽  
Plate System

The superior characteristics of the “Imaging Plate” (IP) for electrons have already been ascertained, and its fundamental characteristics and application data reported. Conventionally, however, the IP, which was developed for X-ray radiography was applied to TEM image recording. So, its superior characteristics had not been given full play and it had been necessary to optimally redesign the IP for TEM. This report introduces our newly developed Imaging Plate System for TEM (TEM-IP System), which includes processes of taking, reading, processing and printing images.Fig.l shows the block diagram of the TEM- IP system. The newly developed devices are as follows:1.IP for TEM2.Camera chamber of TEM3.Image reader (including eraser)4.Image processor5.Printer.<Magazine-to-magazine form> The IP exposed in the camera chamber, can be loaded in the image reader together with its magazine, Lo carry out image reading. After completion of image reading and erasing in the image reader, the IP can be reloaded in the camera chamber, for repeated exposure.

Fluorescence effects in quantitative microprobe analysis

1990 ◽  
Vol 48 (2) ◽  
pp. 188-189
Author(s):  
S.J.B. Reed
Keyword(s):  
Microprobe Analysis ◽  
Depth Distribution ◽  
Exciting Radiation ◽  
Primary Radiation ◽  
List Type ◽  
Type Number ◽  
Computing Power ◽  
X Ray ◽  
Fluorescent Radiation

Characteristic fluorescenceThe theory of characteristic fluorescence corrections was first developed by Castaing. The same approach, with an improved expression for the relative primary x-ray intensities of the exciting and excited elements, was used by Reed, who also introduced some simplifications, which may be summarized as follows (with reference to K-K fluorescence, i.e. K radiation of element ‘B’ exciting K radiation of ‘A’):1.The exciting radiation is assumed to be monochromatic, consisting of the Kα line only (neglecting the Kβ line).2.Various parameters are lumped together in a single tabulated function J(A), which is assumed to be independent of B.3.For calculating the absorption of the emerging fluorescent radiation, the depth distribution of the primary radiation B is represented by a simple exponential.These approximations may no longer be justifiable given the much greater computing power now available. For example, the contribution of the Kβ line can easily be calculated separately.

Directional Persistence in the Rewarded Alternation Model of Obsessive-compulsive Disorder is Responsive to both Dopaminergic and Serotonergic Manipulations

2009 ◽  
Vol 24 (S1) ◽  
pp. 1-1
Author(s):  
D. Kontis ◽  
V. Boulougouris ◽  
S. Papadopoulos ◽  
V.-M. Papakosta ◽  
S. Kalogerakou ◽  
...  
Keyword(s):  
Obsessive Compulsive Disorder ◽  
Low Dose ◽  
Receptor Activation ◽  
Common Mechanism ◽  
High Dose ◽  
List Type ◽  
Type Number ◽  
Obsessive Compulsive ◽  
Compulsive Disorder ◽  
Serotonin Agonist

Rationale:In the rewarded alternation model of obsessive compulsive disorder (OCD), the serotonin agonist m-chlorophenylpiperazine (mCPP) increases persistent behaviour, while chronic pretreatment with selective serotonin reuptake inhibitor (SSRI-fluoxetine) but not benzodiazepine or desipramine abolishes mCPP effects. However, we noted that acute SSRI administration also causes transient persistence increases, counteracted by mCPP pretreatment.Objectives:This studya.further explores the apparent cross-tolerance between fluoxetine and mCPP andb.extends the model by investigating its sensitivity to dopaminergic manipulations (D2,3 agonism - quinpirole).Methods:In both experiments, baseline and drug testing was carried out under daily T-maze alternation training.Exp.1:Matched group (n=8) pairs of rats received one of the following 20-day pretreatments (daily intraperitoneal administration):1.saline,2.low-dose fluoxetine (2.5mg/kg),3.low-dose mCPP (0.5mg/kg) or4.combined fluoxetine+mCPP.One group per pretreatment then received a 4-day challenge with high-dose fluoxetine (10mg/kg), the other with high-dose mCPP (2.5mg/kg).Exp.2:One group (n=12) of rats received 20-day treatment with saline, another with quinpirole (0.5 mg/kg).Results:Exp.1:Saline and low-dose mCPP- or fluoxetine-pretreated animals showed significant persistence increases under both challenges, while combined low-dose fluoxetine+mCPP pretreatment afforded full protection from either challenge.Exp.2:Quinpirole significantly increased directional persistence after 13 administration days.Conclusions:These results establish the sensitivity of the rewarded alternation OCD model to D2,3receptor activation, thereby extending its profile of pharmacological isomorphism with OCD. Furthermore, they suggest a common mechanism of action of an SSRI and a serotonin agonist in the control of directional persistence.

scholarly journals Solar X radiation

1965 ◽  
Vol 23 ◽  
pp. 45-52 ◽  
Author(s):  
C. de Jager
Keyword(s):  
Electromagnetic Radiation ◽  
Gamma Rays ◽  
Electronic Transitions ◽  
List Type ◽  
X Rays ◽  
Type Number ◽  
X Ray ◽  
Image Position ◽  
Electron Shells

X-ray bursts are defined as electromagnetic radiation originating from electronic transitions involving the lowest electron shells; gamma rays are of nuclear origin. Solar gamma rays have not yet been discovered.According to the origin we have : 1.Quasi thermal X-rays, emitted by (a) the quiet corona, (b) the activity centers without flares, and (c) the X-ray flares.2.Non-thermal X-ray bursts; these are always associated with flares.The following subdivision is suggested for flare-associated bursts :

scholarly journals A new catalogue of quasi-stellar objects

1986 ◽  
Vol 119 ◽  
pp. 51-52
Author(s):  
A. Hewitt ◽  
G. Burbidge
Keyword(s):  
Seyfert Galaxies ◽  
List Type ◽  
Type Number ◽  
Stellar Objects ◽  
Bl Lac Objects ◽  
X Ray ◽  
Bl Lac ◽  
Similar Information ◽  
Quasi Stellar Objects ◽  
Objective Prism

We have prepared a new catalogue of QSOs and BL Lac objects containing approximately 3400 entries. A complete update of the Hewitt-Burbidge (1980) catalogue has been made with approximately another 2000 objects with known redshifts added. The references to discovery, magnitudes, redshifts, color, spectra and polarimetry have been updated for the objects listed in 1980, and complete new references are included for the new objects. In addition to the basic optical information, the new catalogue also contains X-ray, radio and infrared information for all objects. Absorption redshifts are listed when they are available. A supplementary catalogue which is now in preparation will contain similar information for objects described variously as Seyfert galaxies, N systems and AGNs. In doubtful cases we have used the operational dividing line ƶ = 0.1. All objects with ƶ < 0.1 are put in the supplementary catalogue unless their discoverers have unambiguously defined them as QSOs. With approximately twice as many objects included it is interesting to note that: a)There are still very few genuine BL Lac objects, ∼100.b)The largest number of additions has come from identifications using the objective prism-grism techniques.

scholarly journals The K-Band Hubble Diagram for X-Ray Selected Brightest Cluster Galaxies

1998 ◽  
Vol 179 ◽  
pp. 339-341
Author(s):  
R.G. Mann ◽  
C.A. Collins
Keyword(s):  
Star Formation ◽  
List Type ◽  
Type Number ◽  
Hubble Diagram ◽  
Technical Problems ◽  
X Ray ◽  
Cluster Galaxies ◽  
Brightest Cluster Galaxies ◽  
The Absolute ◽  
Small Dispersion

The Hubble (magnitude-redshift) diagram for brightest cluster galaxies (BCGs) is a classic cosmological tool, widely studied because of the remarkably small dispersion (∼ 0.3 mag) in the absolute optical magnitudes of low redshift BCGs (Postman and Lauer 1995). Extending the BCG Hubble diagram to higher redshifts would greatly enhance its role as a cosmological probe, but this has been frustrated by several technical problems: – the conventional means of cluster selection in the optical become increasingly compromised by projection effects at z > 0.1– at higher redshifts the interpretation of optical magnitudes becomes increasingly complicated by the effects of possible star formation.

scholarly journals 4 Years of Radio to X-ray Observations of 3C 273

1989 ◽  
Vol 134 ◽  
pp. 112-113
Author(s):  
T.J.-L. Courvoisier ◽  
E. I. Robson ◽  
A. Blecha ◽  
P. Bouchet
Keyword(s):  
Near Infrared ◽  
Optical Emission ◽  
Light Curves ◽  
Physical Parameters ◽  
List Type ◽  
Type Number ◽  
Rapid Variability ◽  
X Ray ◽  
Model Independent ◽  
Ir Emission

The quasar 3C273 has been repeatedly observed at radio, mm, IR, optical, UV and X-ray frequencies since December 1983. A complex pattern of continuum variations has been discovered, which can be used to provide model independent physical parameters, and to constrain different models. The main features revealed by our set of observations are: (i)A flux decrease by 40% in the 2–10 kev flux in 20 days in early 1984 (Courvoisier et al. 1987).(ii)Differences between the X-ray light curves at 0.5 keV and 2–10 keV.(iii)A drop in the mm to mid-IR emission by factors 2–4 in early 1986, while the near infrared flux remained stable (Robson et al. 1986).(iv)A decrease in the ultraviolet intensity of ∼40% in about 6 months in 1987 (Ulrich, Courvoisier and Wamsteker 1988).(v)Rapid variability in the infrared and optical emission on timescales as short as one day in 1988 (Courvoisier et al. 1988 and Robson, Courvoisier and Bouchet this conference).

Hitachi Model XMA-5 Electron Probe Microanalyzer

1968 ◽  
Vol 26 ◽  
pp. 308-309
Author(s):  
Tomura ◽  
Okano ◽  
Hara
Keyword(s):  
Electron Probe ◽  
High Performance ◽  
List Type ◽  
X Rays ◽  
Type Number ◽  
Fluorescence Excitation ◽  
X Ray ◽  
Electron Probe Microanalyzer ◽  
Scientific Instrumentation ◽  
Made In

The recent advancement in scientific instrumentation has been phenomenal. This is particularity true in the electron probe microanalyzer field. This paper describes the improvements made in the Hitachi Model XMA-5 Electron Probe Microanalyzer to achieve high performance.1.X-ray spectroscopy1-1.It is now possible to analyze a wide variety of elements including ultra light elements in minute concentrations with the advent of an increasing number of dispersing elements and high detectability.1-2.A linear crystal drive and direct wavelength read-out (with respect to the crystal) is employed in the spectrometer to assure simultaneous analyses of up to three elements by using three of the six crystals provided. For correction of absorbed X-rays and fluorescence excitation and with due consideration of the angular distribution of the characteristic X-rays, an X-ray take off angle of 38° (electron probe is incident vertically on the specimen surface) was adopted.

Testing ZAF and related procedures

1992 ◽  
Vol 50 (2) ◽  
pp. 1638-1639
Author(s):  
Kurt F. J. Heinrich
Keyword(s):  
Absorption Coefficient ◽  
Cross Section ◽  
Internal Consistency ◽  
List Type ◽  
Type Number ◽  
Data Types ◽  
Experimental Conditions ◽  
X Ray ◽  
Continuous Radiation

Conventional ZAF procedures, Pouchou and Pichoir's PAP and XPP procedures (transcribed into a ZAF format), Scott and Love's procedure, and the f(ρz) procedures by Brown and by Packwood (all described in ref.) were tested by a modular program in Turbopascal which permits selecting separately the procedures for electron deceleration, backscattering (except the ϕ(ρz) procedures),absorption, fluorescence by characteristic and by continuous radiation. Parameters such as the absorption coefficient, the J factor, fluorescent yield and inner shell cross section can also be selected from the menu.The data used for the evaluation are from binary specimens. They were collected from publications by various authors, with addition of some unpublished data generated at NBS by R. Marinenko and H. Konuma. The following data types were excluded: 1.most data obtained with x-ray emergence angles below 30°.2.single values, not corroborated by measurements of other concentrations or under other experimental conditions.3.sets of measurements showing lack of internal consistency.

A Study on the Occurrence of Gold in Unoxidized Carlin-Type Ores in China Using AEM, SEM-EDX and SXRF

1990 ◽  
Vol 48 (2) ◽  
pp. 414-415
Author(s):  
Liu Yongkang ◽  
Liu Shirong ◽  
Wan Guangquan ◽  
Zhou Lindi ◽  
Li Jilian ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Gold Mineralization ◽  
Analytical Electron Microscopy ◽  
List Type ◽  
Type Number ◽  
X Ray ◽  
Combined Use ◽  
Analytical Electron ◽  
Scanning Electron ◽  
Gold Bearing

The knowledge about the occurrence of gold is essential both to the explanation for the genesis of gold mineralization in its deposits and to the evaluation and exploration or even smelt process of its ores. It has been well known that the gold occurrence in the Carlin-type ores still remains a difficult question to be answered because of the tiny scale of its locality and its very low content.This paper reports the results of our analysis on some gold bearing minerals in the Carlin-type ores discovered during recent years in China with combined use of analytical electron microscopy (AEM), scanning electron microscopy-energy dispersive X ray spectrometry (SEM-EDX) and synchrotron X ray flourescence analysis (SXRF) techniques as following:(1) Some gold occurred as submicron size grains in the ores (see Photo 1-4 and Figure 1-3) with grain size generally less than 0.2 micron.(2) It has been found by AEM and SEM-EDX observation and SXRF analysis that gold occurred as micrograins embedded in the boundaries of clay or quartz minerals rather than, as said, entered the lattice or adhered as a covering film to the surface of clay minerals (see Figure 4).

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