scholarly journals Study of variability of 2MASSJ10183905+0014078 stellar objects

2019 ◽  
pp. 60-65
Author(s):  
E. C. Romas
Keyword(s):  
Spectral Characteristics ◽  
Type Ii ◽  
Slow Increase ◽  
Stellar Objects ◽  
X Ray ◽  
Spectral Class ◽  
Photometric Observations ◽  
Type Object ◽  
Brightness Variability ◽  
Made In

This paper presents observational data for the star 2MASSJ10183905+0014078 (UCAC4 452-048383), in which so far no brightness variability has been detected. However, photometric observations made in 2015 allowed recording are activity with an amplitude of 0.8 m for this star. The star parameters, namely magnitude and color index (V0 = 7.59, (B - V)0 = 1.19) and, therefore, the position on the Hertzsprung-Russell diagram, luminosity (L☉ = 0.1), spectral class (K7), mass (M☉ = 0.6), the spectral characteristics in the optical (Ca, Fe, Na D, H_ lines, Mg H, and TiO bands) and X-ray ranges allow us to classify the star as UVCet type object. The ash profile can be attributed to type II, with a relatively slow increase and decrease in brightness.

Study of Pulsations in the Nova-like Variable KR Aur and the Intermediate Polar BG CMi

1991 ◽  
Vol 9 (2) ◽  
pp. 279-280
Author(s):  
J. Singh ◽  
P. C. Agrawal ◽  
M. V. K. Apparao ◽  
R. K. Manchanda ◽  
P. Vivekananda Rao ◽  
...  
Keyword(s):  
Neutron Star ◽  
White Dwarf ◽  
Accretion Disc ◽  
Light Curves ◽  
Pulsation Period ◽  
Variable Amplitude ◽  
X Ray ◽  
Photometric Observations ◽  
The Times ◽  
Made In

AbstractFast photometric observations of a nova-like variable KR Aurigae and the intermediate polar BG CMi (3A0729+103) were made in the B and U bands during 1984–89 to study pulsations in them. The light curves of KR Aur show large amplitude quasi-periodic pulsations with periods in the range 500–800s which can be ascribed to inhomogeneities in the accretion disc. The light curves of the X-ray emitting intermediate polar BG CMi show variable amplitude pulsations with 913s period. From the times of maxima of the pulsations obtained from observations over the period 1984–1989, the pulsation period is derived to be 0.010572966 ± 8 days and the spin-up rate to be (−5.7 ± 0.5) × 10−11 ss−1. The spin-up rate is consistent with the pulsating source being a white dwarf and not a neutron star.

scholarly journals X-ray microanalysis of dentine in primary teeth diagnosed Dentinogenesis Imperfecta type II

2019 ◽  
Vol 21 (4) ◽  
pp. 527-535 ◽  
Author(s):  
N. Sabel ◽  
J. G. Norén ◽  
A. Robertson ◽  
D. H. Cornell
Keyword(s):  
Elemental Composition ◽  
Primary Teeth ◽  
Root Surface ◽  
Type Ii ◽  
Dentinogenesis Imperfecta ◽  
X Ray ◽  
Made In ◽  
Inductive Analysis

Abstract Aim To analyse the elemental composition of dentine in primary teeth from children diagnosed with Dentinogenesis Imperfecta type II (DI) and from normal sound primary teeth using X-ray microanalysis. Materials and methods X-ray microanalysis of the elements C, O, Na, Mg, P, Cl, K and Ca were performed in the dentine of five normal primary teeth and in seven primary teeth diagnosed DI. The analysis was made in a low magnification in 10 points from the enamel-dentine junction/root surface toward the pulp. The data was also evaluated with an inductive analysis. Results Lower values for C were found in DI-dentine compared with normal dentine. Na had significantly higher values in DI-dentine while Mg had significantly lower values. The inductive analysis revealed that Na and Mg were the most important elements for discriminating DI-dentine from normal dentine. Conclusions Dentine in primary teeth from patients diagnosed with Dentinogenesis Imperfecta type II analysed with XRMA have lower values of C and Mg and higher values of O and Na compared with normal primary dentine.

Microanalysis of precipitates in a ferritic steel

1978 ◽  
Vol 36 (1) ◽  
pp. 618-619
Author(s):  
J.M. Titchmarsh
Keyword(s):  
Ferritic Steel ◽  
Particle Identification ◽  
Energy Dispersive ◽  
Objective Lens ◽  
Ferritic Steels ◽  
Replica Technique ◽  
X Ray ◽  
Large Numbers ◽  
Scanning Transmission ◽  
Made In

The advances in recent years in the microanalytical capabilities of conventional TEM's fitted with probe forming lenses allow much more detailed investigations to be made of the microstructures of complex alloys, such as ferritic steels, than have been possible previously. In particular, the identification of individual precipitate particles with dimensions of a few tens of nanometers in alloys containing high densities of several chemically and crystallographically different precipitate types is feasible. The aim of the investigation described in this paper was to establish a method which allowed individual particle identification to be made in a few seconds so that large numbers of particles could be examined in a few hours.A Philips EM400 microscope, fitted with the scanning transmission (STEM) objective lens pole-pieces and an EDAX energy dispersive X-ray analyser, was used at 120 kV with a thermal W hairpin filament. The precipitates examined were extracted using a standard C replica technique from specimens of a 2¼Cr-lMo ferritic steel in a quenched and tempered condition.

Searching for the causes why some of the paintings by Mihaly Munkacsy are darkening

1990 ◽  
Vol 48 (2) ◽  
pp. 204-205
Author(s):  
Imre Pozsgai ◽  
Klara Erdöhalmi-Torok
Keyword(s):  
Electron Beam ◽  
Cross Section ◽  
Polyester Resin ◽  
National Gallery ◽  
X Ray ◽  
Art Historians ◽  
Made In ◽  
Grinding And Polishing

The paintings by the great Hungarian master Mihaly Munkacsy (1844-1900) made in an 8-9 years period of his activity are deteriorating. The most conspicuous sign of the deterioration is an intensive darkening. We have made an attempt by electron beam microanalysis to clarify the causes of the darkening. The importance of a study like this is increased by the fact that a similar darkening can be observed on the paintings by Munkacsy’s contemporaries e.g Courbet and Makart. A thick brown mass the so called bitumen used by Munkacsy for grounding and also as a paint is believed by the art historians to cause the darkening.For this study, paint specimens were taken from the following paintings: “Studio”, “Farewell” and the “Portrait of the Master’s Wife”, all of them are the property of the Hungarian National Gallery. The paint samples were embedded in a polyester resin “Poly-Pol PS-230” and after grinding and polishing their cross section was used for x-ray mapping.

X-ray mapping without STEM

1994 ◽  
Vol 52 ◽  
pp. 508-509
Author(s):  
Judith M. Brock ◽  
Max T. Otten
Keyword(s):  
Life Science ◽  
Materials Science ◽  
Chemical Elements ◽  
Full Description ◽  
Scanning System ◽  
Elemental Distribution ◽  
X Ray ◽  
Transmission Electron ◽  
Distribution Of Elements ◽  
Made In

A knowledge of the distribution of chemical elements in a specimen is often highly useful. In materials science specimens features such as grain boundaries and precipitates generally force a certain order on mental distribution, so that a single profile away from the boundary or precipitate gives a full description of all relevant data. No such simplicity can be assumed in life science specimens, where elements can occur various combinations and in different concentrations in tissue. In the latter case a two-dimensional elemental-distribution image is required to describe the material adequately. X-ray mapping provides such of the distribution of elements.The big disadvantage of x-ray mapping hitherto has been one requirement: the transmission electron microscope must have the scanning function. In cases where the STEM functionality – to record scanning images using a variety of STEM detectors – is not used, but only x-ray mapping is intended, a significant investment must still be made in the scanning system: electronics that drive the beam, detectors for generating the scanning images, and monitors for displaying and recording the images.

Healing of Circular Defects in the Rabbit Medial Meniscus Can Occur Spontaneously and Is not Improved by Intra-Articular Hyaluronic Acid

1996 ◽  
Vol 09 (02) ◽  
pp. 60-5 ◽  
Author(s):  
N. Hope ◽  
P. Ghosh ◽  
S. Collier
Keyword(s):  
Hyaluronic Acid ◽  
Medial Meniscus ◽  
Chondroitin Sulphate ◽  
Rabbit Model ◽  
Type Ii Collagen ◽  
Type Ii ◽  
Keratan Sulphate ◽  
Meniscal Healing ◽  
Meniscus Healing ◽  
Made In

SummaryThe aim of this study was to determine the effects of intra-articular hyaluronic acid on meniscal healing. Circular defects, 1.0 mm in diameter, were made in the anterior third of the medial meniscus in rabbits. In one joint, 0.4 ml hyaluronic acid (Healon®) was instilled, and in the contralateral (control) joint, 0.4 ml Ringer’s saline. Four rabbits were killed after four, eight and 12 weeks and the menisci examined histologically. By eight weeks most of the lesions had healed by filling with hyaline-like cartilage. Healing was not improved by hyaluronic acid treatment. The repair tissue stained strongly with alcian blue, and the presence of type II collagen, keratan sulphate, and chondroitin sulphate was demonstrated by immunohistochemical localisation. In contrast to the circular defects, longitudinal incisions made in the medial menisci of a further six rabbits did not show any healing after 12 weeks, indicating that the shape of the lesion largely determined the potential for healing.The effect of hyaluronic acid on meniscal healing was tested in a rabbit model. With one millimeter circular lesions in the medial meniscus, healing by filling with hyalinelike cartilage was not significantly affected by the application of hyaluronic acid intra-articularly at the time of surgery, compared to saline controls, as assessed histologically four, eight and 12 weeks after the operation.

scholarly journals Principles of Different X-ray Phase-Contrast Imaging: A Review

2021 ◽  
Vol 11 (7) ◽  
pp. 2971
Author(s):  
Siwei Tao ◽  
Congxiao He ◽  
Xiang Hao ◽  
Cuifang Kuang ◽  
Xu Liu
Keyword(s):  
Biological Samples ◽  
Phase Contrast ◽  
Recent Progress ◽  
Phase Contrast Imaging ◽  
Contrast Imaging ◽  
X Ray ◽  
X Ray Imaging ◽  
Internal Structures ◽  
X Ray Absorption ◽  
Made In

Numerous advances have been made in X-ray technology in recent years. X-ray imaging plays an important role in the nondestructive exploration of the internal structures of objects. However, the contrast of X-ray absorption images remains low, especially for materials with low atomic numbers, such as biological samples. X-ray phase-contrast images have an intrinsically higher contrast than absorption images. In this review, the principles, milestones, and recent progress of X-ray phase-contrast imaging methods are demonstrated. In addition, prospective applications are presented.

The properties of the dusty inner regions of nearby QSOs

2019 ◽  
Vol 15 (S356) ◽  
pp. 95-95
Author(s):  
Itziar Aretxaga
Keyword(s):  
Star Formation ◽  
Polycyclic Aromatic Hydrocarbon ◽  
Aromatic Hydrocarbon ◽  
Stellar Objects ◽  
X Ray ◽  
Mir Spectroscopy ◽  
Polycyclic Aromatic ◽  
Quasi Stellar Objects

AbstractWe present MIR spectroscopy and photometry obtained with CanariCam on the 10.4 m Gran Telescopio CANARIAS for a sample of 20 nearby, MIR bright and X-ray luminous quasi-stellar objects (QSOs). We find that for the majority of QSOs the MIR emission is unresolved at angular scales ∼0.3 arcsec. We derive the properties of the dusti tori that surround the nucleus based on these observations and find significant differences in the parameters compared with a sample of Seyfert 1 and 2 nuclei. We also find evidence for polycyclic aromatic hydrocarbon (PAH) features in the spectra, indicative of star formation, more centrally peaked (on scales of a few hundred pc) than previously believed.

scholarly journals Non-destructive handheld XRF study of archaeological composite silver objects—the case study of the late Roman Seuso Treasure

2021 ◽  
Vol 13 (5) ◽  
Author(s):  
Viktória Mozgai ◽  
Bernadett Bajnóczi ◽  
Zoltán May ◽  
Zsolt Mráv
Keyword(s):  
Fluorescence Analysis ◽  
The Body ◽  
High Quality ◽  
X Ray ◽  
Composite Objects ◽  
Mechanical Attachment ◽  
Non Destructive ◽  
Made In ◽  
Late Roman

AbstractThis study details the non-destructive chemical analysis of composite silver objects (ewers, situlas, amphora and casket) from one of the most significant late Roman finds, the Seuso Treasure. The Seuso Treasure consists of fourteen large silver vessels that were made in the fourth–early fifth centuries AD and used for dining during festive banquets and for washing and beautification. The measurements were systematically performed along a pre-designed grid at several points using handheld X-ray fluorescence analysis. The results demonstrate that all the objects were made from high-quality silver (above 90 wt% Ag), with the exception of the base of the Geometric Ewer B. Copper was added intentionally to improve the mechanical properties of soft silver. The gold and lead content of the objects shows constant values (less than 1 wt% Au and Pb). The chemical composition as well as the Bi/Pb ratio suggests that the parts of the composite objects were manufactured from different silver ingots. The ewers were constructed in two ways: (i) the base and the body were made separately, or (ii) the ewer was raised from a single silver sheet. The composite objects were assembled using three methods: (i) mechanical attachment; (ii) low-temperature, lead-tin soft solders; or (iii) high-temperature, copper-silver hard solders. Additionally, two types of gilding were revealed by the XRF analysis, one with remnants of mercury, i.e. fire-gilding, and another type without remnants of mercury, presumably diffusion bonding.

X‐Ray, Optical, and Radio Observations of the Type II Supernovae 1999em and 1998S

2002 ◽  
Vol 572 (2) ◽  
pp. 932-943 ◽  
Author(s):  
David Pooley ◽  
Walter H. G. Lewin ◽  
Derek W. Fox ◽  
Jon M. Miller ◽  
Christina K. Lacey ◽  
...  
Keyword(s):  
Type Ii ◽  
Radio Observations ◽  
X Ray
Sign in / Sign up

Export Citation Format

Share Document