Cinématographie ultrarapide dans le domaine des courtes longueurs d'onde

1994 ◽  
Vol 72 (11-12) ◽  
pp. 818-821
Author(s):  
C. Y. Côté ◽  
M. Nantel ◽  
J. Gauthier ◽  
J. C. Kieffer

We present some recent results on the temporal evolution of X-ray images and spectra of laser produced plasmas. These results illustrate our progress in the development of a new technology for subpicosecond cinematography. We discuss the perspectives of such a technology for the control and optimization of ultrashort X-ray sources.[Journal translation]

2003 ◽  
Vol 9 (S02) ◽  
pp. 1452-1453 ◽  
Author(s):  
W. J. Kozek ◽  
A. Nair ◽  
G. Denbeaux ◽  
C. Larabell ◽  
J. Brown ◽  
...  
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2017 ◽  
Vol 13 (S337) ◽  
pp. 326-327
Author(s):  
Francesco Coti Zelati

AbstractWe present the results of a systematic study of all magnetar outbursts observed to date through a reanalysis of data acquired in about 1100 X-ray observations. We track the temporal evolution of the luminosity for all these events, model empirically their decays, and estimate the characteristic decay time-scales and the energy involved. We study the link between different parameters, and reveal several correlations between different quantities. We discuss our results in the framework of the models proposed to explain the triggering mechanism and evolution of magnetar outbursts.


2020 ◽  
Vol 1010 ◽  
pp. 418-423
Author(s):  
Nor Atiq Syakila Mohd Nazmi ◽  
Wan Nazwanie Wan Abdullah ◽  
Farook Adam ◽  
Wan Nur Aini Wan Mokhtar ◽  
Noor Fatimah Yahaya ◽  
...  

— The catalytic oxidative desulfurization (Cat-ODS) process has been introduced as a new technology to achieve ultra-low sulphur levels in diesel fuels. In this study, the performance of the alumina supported iron oxide based catalysts doped with cobalt, synthesized via wet impregnation method on the Cat-ODS of the model diesel with the total sulphur 500ppm was investigated using tert-butyl hydroperoxide (TBHP) as an oxidizing agent and N,N-dimethylformamide as an extraction solvent. A series of dopant was being screened. Co/Fe-Al2O3 (10:90) and Co/Fe-Al2O3 (20:80) prepared at 400°C. Overall, the catalytic activity decreased as dopant ratio increased. Catalyst with 10 wt% of Co was successfully removed 96% of thiophene, 100% of DBT and 92% of 4,6-DMDBT in model diesel. Further investigation, potential catalyst that calcined at 400°C contributed higher sulphur removal compared to the catalyst calcined at 500°C. X-ray diffraction analysis (XRD) result showed that Co/Fe-Al2O3 (10:90) prepared at 400°C was amorphous, while micrograph of the field emission scanning electron microscopy (FESEM) illustrated an inhomogeneous distribution of various particle sizes. The energy dispersive X-ray analysis (EDX) result have confirmed the presence of Fe and Co in all of the prepared catalyst.


2010 ◽  
Vol 437 ◽  
pp. 73-78 ◽  
Author(s):  
Albert Weckenmann ◽  
Philipp Krämer

As a rather new technology, X-Ray Computed Tomography offers new and promising possibilities in manufacturing metrology in comparison to well-established tactile or optical measurements. The main benefit is the volumetric model which results of each measurement and represents the measurement object holistically with high point density.


1990 ◽  
Vol 185 ◽  
Author(s):  
Dusan Stulik ◽  
Eric Doehne

AbstractThe principles of Environmental Scanning Electron Microscopy (E-SEM) are explained and discussed. The performance of the E-SEM compares favorably with the performance of traditional SEM instruments. This new technology has significant advantages in art conservation and archaeology. In this paper we describe several pilot studies which explored potential uses of the E-SEM. Electron micrographs recorded from moist, outgassing, and difficult to coat samples are presented, together with X-ray spectra recorded from uncoated samples of electrically nonconductive materials.


Author(s):  
Mohamed Elgendi ◽  
Rich Fletcher ◽  
Newton Howard ◽  
Carlo Menon ◽  
Rabab Ward

High-resolution computed tomography radiology is a critical tool in the diagnosis and management of COVID-19 infection; however, in smaller clinics around the world, there is a shortage of radiologists available to analyze these images. In this paper, we compare the performance of 16 available deep learning algorithms to help identify COVID19. We utilize an already existing diagnostic technology (X-ray) and an already existing neural network (ResNet-50) to diagnose COVID-19. Our approach eliminates the extra time and resources needed to develop new technology and associated algorithm, thus aiding the front-line in the race against the COVID-19 pandemic. Results show that ResNet-50 is the optimal pretrained neural network for the detection of COVID-19, using three different cross-validation ratios, based on training time, accuracy, and network size. We also present a custom visualization of the results that can be used to highlight important visual biomarkers of the disease and disease progression.


2001 ◽  
Vol 7 (S2) ◽  
pp. 884-885
Author(s):  
Paul Smith ◽  
John Gannon ◽  
Frank Eggert

RÖNTEC’s UHV Dewar detectors have established new standards for high resolution, lowmaintenance, low operating cost, and reliability in Si(Li) X-ray detectors. Now, the recently introduced XFlash® series X-ray detectors are enabling new methodologies for microanalysis and element imaging in the SEM. These detectors are compact, liquid-nitrogen-free semiconductor Xray detectors that are based on Silicon Drift Diode (SDD) technology. XFlash detectors produce extraordinarily high count rates with excellent energy resolution and have introduced ultra-fast microanalysis and element mapping to the SEM world. The addition of color to SEM images enables easy visualization of element distributions and allows the microstructural features and compositional variations of different materials to be more readily identified. Persons unfamiliar with electron microscopy can more readily interpret color images than black and white or gray scale images. This new technology has great potential to revolutionize electron microscopy.RÖNTEC’s UHV Dewar Detector offers the highest long-term stability and best energy resolution ever specified for a commercial Si(Li) detector (less than 129 eV). The UHV design leads to small size and weight (for reduced column loading) along with extremely low nitrogen consumption and low susceptibility to microphonics. The UHV detector never ices up and thus never requires defrosting or warm-ups. It is available with a variety of entrance windows for light element analysis.


1985 ◽  
Vol 29 ◽  
pp. 235-242 ◽  
Author(s):  
Frank N. Blanchard ◽  
Robert E. Goddard ◽  
Barbara Saffer

Phosphorite is a sedimentary rock with a high enough content of phosphate minerals to bo of economic Interest. Most phosphorites are composed predominantly of m1crocrystall1no to cryptocrystalline carbonate fluorapatlte thenceforth In this report referred to simply by the mineral group name apatite). Florida produces roughly 1/3 of the world's supply of phosphate rock, most of which is used 1n the fe rtiliz e r Industry.Long term continuation of phosphorite mining In Florida will require exploitation of the extensive hlgh-magneslum phosphorite deposits south of the present mining d istrict 1n central Florida, and this will require new technology In order to produce beneficlated concentrates with less than 1% MgO, a limit Imposed by fe r tiliz e r processing technology. In order to develop benefication methods applicable to these ores, it is essential to know how Mg occurs in phosphorites. Dolomite, CaMg(C03)2, is the chief host of Mg In phosphorites from Florida. Magnesium may also be present, however, as a substituent In apatite (the chief phosphate.mineral in these deposits), as a minor substituent 1n calcite (CaCO3), in certain clay minerals (particularly palygorskite and to a lesser extent in some smectites), and/or in organic matter within the apatite particles.


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