Composition of Coal Dusts and Their Cytotoxicity on Alveolar Macrophages

Coal mine dust is produced from complex materials which consist of organic sedimentary phases, inorganic minerals, and trace elements. The dust varies in its chemical compositions and is capable of causing lung injury when inhaled. The purpose of this study was to perform scanning electron microscopy combined with energy dispersive spectrometry, wavelength dispersive spectrometry and X-ray diffraction analyses of three coal dusts and examine their effects on rat lung alveolar macrophages (AM) in cell culture. The coal dusts were obtained from coal surfaces of anthracite, meager and fat coal mines. AM were harvested by bronchoalveolar lavage from adult male Wistar rats and were cultured in Eagle's medium at 37°C.

The Evolution of X-Ray Instrumentation at Rich. Seifert & Co.

To facilitate orientation in time, some selected events will be briefly presented. Approximately five hundred years ago, Columbus discovered America. One hundred years ago, on November 8th, 1895, Wilhelm Conrad R6ntgen discovered the X-rays which in the German language are called after him. In 1912 Max von Laue conducted the first X-ray diffraction experiment. In 1892 Richard Seifert Sr. founded the Electrotechnical Plant in Hamburg. After World War I (1914-1918) the company founder gradually handed the firm over to his son Richard Seifert Jr. After his son had completed studies in physics and electrical engineering he conducted pioneering experiments on the application of X-rays in science and technology. From the very beginning, X-ray equipment was produced in the three fields of medicine, science and technology. It was only ten years after World War II (1939-1945) that the line of medical equipment was discontinued and the daughter [1] as a member of the third generation gradually took over executive management tasks.

New Rotating Anode X-Ray Generator For XAFS Experiments

A high-power X-ray generator equipped with a lanthanum hexaboride cathode has been developed for X-ray absorption fine structure experiments. A high tube-current of more than 1,000 mA can be provided when operated at low tube-voltage of less than 20 kV. In addition, the focal width is narrow enough (less than 0.1 mm) to ensure good energy resolution. Extremely intense monochromatic X-rays (106 ∼ 107 counts/(sec.mm2) at the sample position), which are completely free from higher order harmonics and tungsten contamination lines, are available, when a Johansson-type spectrometer is employed. The filament life has been significantly prolonged by the high vacuum specification of the tube.

Evolution of X-Ray Instrumentation & Techniques, 1970-1990

While both X-ray Fluorescence Analysis and X-ray Powder Diffractometry have their roots back in the earlier half of this century it wasn't until the 1960s that the two techniques became widely accepted. The growth in the application of X-ray methods for materials analysis grew rapidly between 1960 and 1970, then gained another major leap forward in the early ‘70s with the introduction of mincomputers. The introduction of Si(Li) detectors in the late’ 60s and early ‘70s added a further dimension to the available instrumentation. This paper reviews the growth in the field of X-ray materials analysis and highlights the major mile-stones in intrumentation and techniques.

Improvement of the Detection Sensitivity of Edxrf Trace Element Analysis by Means of Efficient X-Ray Focusing Based on Strongly Curved Hopg Crystals

X-ray focusing based on Bragg reflection at curved crystals allows collection of a large solid angle of incident radiation, monochromatization of this radiation, and condensation of the beam reflected at the crystal into a small spatial cross-section in a pre-selected focal plane. Thus, for the Bragg reflected radiation, one can achieve higher intensities than for the radiation passing directly to the same small area in the focal plane. In that case one can profit considerably from X-ray focusing in an EDXRF arrangement. The 00 2 reflection at Highly Oriented Pyrolytic Graphite (HOPG) crystals offers a very high intensity of the Bragg reflected beam for a wide range of photon energies. Furthermore, curvature radii smaller than 10 mm can be achieved for HOPG crystals ensuring efficient X-ray focusing in EDXRF applications. For the trace analysis of very small amounts of specimen material deposited on small areas of thin-filter backings, HOPG based X-ray focusing may be used to achieve a very high intensity of monochromatic excitation radiation.

X-Ray Fluorescence Cross-Section Measurements in the Energy Range 4-18 keV

K, L and M shell x-ray fluorescence cross sections have been measured for elements 11 ≤, Z ≤, 92 at excitation energies corresponding to weighted average energies of K-lines of Ti-K (4.558 keV), Fe-K (6,480 keV), Ge-K (10.024 keV), Se-K (11.391 keV) and Mo-K (17.805 keV) . The measurements were performed with an energy-dispersive x-ray spectrometer in a vacuum chamber using thin ultra-pure targets. Rh x-ray tube and secondary targets were used for excitation of x-ray radiation. The measured x-ray fluorescence cross-sections have been compared to previously published experimental and theoretical results. Presented data can be used for determination of physical parameters such as photoionization cross-sections, fluorescence yields, x-ray emission rates, Coster-Kronig transition probabilities and jump ratios.

Depth profiling by Xrf with Variable Beam Geometry Applied to Thin Films in the Nanometer Region

Standard applications of quantitative XRF are determinations of composition of bulk specimens, composition and thickness of thin multielement layers and thickness of thin element layers. The theoretical background was given by Sherman, and Shiraiwa and Fujino Numerous approaches like empirical coefficients and fundamental parameters were developed and deliver valuable results. Extending the methods to a quantification of very thin layers consisting of more than one chemical element, it becomes more and more complicated to split the solutions into thickness and composition. The explanation is given by the improving validity of the linear approach for the measured signals in dependence on thickness and composition due to the thin layer approximation exp(x)≈l+x. This leads finally to the finding that measured characteristic signals are proportional to the product c-t, where c represents the concentration of the chemical element under investigation and t the thickness of the layer.

Energy Dispersive Grazing Incidence X-ray Diffraction Study on Organic Thin Films EpitaxiaHy Grown on Crystalline Substrate

Thin film technology is rapidly evolving today, and the characterization of the thin film and its surface have become very important issue not only from scientific but also technological viewpoints. Although x-ray diffraction measurements have been used as suitable evaluation methods in crystallography studies, its application to the structural evaluation of the thin films, especially organic one having the low electron densities, is not easy due to the small amounts of scattering volume and the high obstructive scattering noise from the substrate. However, the x-ray diffraction measurements under grazing incidence will aid not only in overcoming the such problems but also in analyzing in-plane structure of the thin films. Therefore, so-called grazing incidence x-ray diffraction (GIXD) has been recognized as one of the most powerful tools for the surface and thin film studies.

Determination of Thickness of Multiple Layer Thin Films by X-ray Diffraction Technique

In this study, the equations based on x-ray diffraction theory were developed to determine the thickness of multiple layer thin films. The kinematical expression of the integrated reflected intensity from the substrate and films was corrected for the primary and secondary extinction effects assuming a mosaic crystal model. As an example of the application of the method, thicknesses of a double heterostructure system, namely AlAs/AIGaAs/GaAs, were determined. Good agreement was obtained between the results from the x-ray measurement and scanning electron microscopy data demonstrating high precision of this technique.