A global geochemical database for environmental and resource management : recommendations for International Geochemical Mapping, final report of IGCP Project 259

Research conducted since 1988 as part of the International Geochemical Mapping (IGM) project has confirmed that the presently available data concerning the geochemical composition of the Earth’s surface are substantially incomplete and internally inconsistent. Many of the older data sets have serious deficiencies and do not meet basic requirements for establishing the range of natural geochemical background values. As a result of natural geological and environmental processes, element abundances in natural materials can vary by several orders of magnitude within short distances. These variations are inadequately documented and their existence is often overlooked in the setting of public policy. A high quality geochemical database is pertinent to a wide range of investigations in the earth and life sciences, and should be considered as an essential component of environmental knowledge. Detailed information about the natural variability of the geochemical background is pertinent to administrative and legal issues as much as to scientific research. Sustainable long-term management of environmental and mineral resources is dependent upon a comprehensive and reliable database. The International Geosphere-Biosphere Program on Global Change requires information on current conditions. Important aspects of change cannot be measured, or their consequences anticipated, unless the present composition of the earth’s surface materials is known. The International Geochemical Mapping project, which was endorsed in 1988 as a contribution to the IGBP (IGBP, 1989), is a multi-stage project established to consider how best to provide quantitative data to portray the geochemical diversity of the earth’s land surface. Participants in IGCP 259 have undertaken a comprehensive review of methods of regional and national geochemical mapping and examined the results obtained. Many problems have been identified and a variety of solutions discussed. Field and laboratory research has been carried out. The resulting recommendations are contained in this report. They are directed towards geochemists and those institutions, which have a mandate for providing an earth science and/or environmental database

Optical Characteristics and Composition of Cd1 – xMnxTe Films Obtained by the Close Spaced Sublimation Technique

Study of the optical properties of Cd1 – xMnxTe films obtained by the close spaced sublimation technique was carried out. Measuring of the optical characteristics of the layers was performed by the spectrophotometric analysis method near the “red boundary” of the semiconductor photoactivity. This research allowed to obtain the spectrum distributions of the transmission T(λ), reflection R(λ) and absorption α(λ) coefficients of the films as well as estimate the band-gap energy of the compound. The values of the band-gap energy were used for determination of manganese concen-trations in the films depending on the growth conditions. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3024

The beam and detector of the NA62 experiment at CERN

NA62 is a fixed-target experiment at the CERN SPS dedicated to measurements of rare kaon decays. Such measurements, like the branching fraction of the K+ → π+ ν bar nu decay, have the potential to bring significant insights into new physics processes when comparison is made with precise theoretical predictions. For this purpose, innovative techniques have been developed, in particular, in the domain of low-mass tracking devices. Detector construction spanned several years from 2009 to 2014. The collaboration started detector commissioning in 2014 and will collect data until the end of 2018. The beam line and detector components are described together with their early performance obtained from 2014 and 2015 data

The elastic strains in the particles inherited by the crystals of martensite, in Cu-A1-Mn alloys

Alloys Cu-A1-Mn containing wt. 12 % A1 and wt. 6-10 % Mn were investigated. The specimens were quenched from 1173 K in water and aged at 423 –773 K. In all alloys during the quenching the particles of phase CU$_{2.2}$Mn$_{0.8}$A1 were generated. These particles were inherited by martensite. The presence of coherence particles of CU$_{2.2}$Mn$_{0.8}$A1 phase, which are non transformed during cooling, lead to the deformation of crystalline lattice of martensite and particles. The AG (chemical driving force of austenite – martensite transformation) and martensitic stresses were evaluated approximate. The short – lived aging caused the increasing of the quantity of the phase CU$_{2.2}$Mn$_{0.8}$A1 and the temperature M$_{\rm s}$. The average martensitic stress, strength of alloys and the driving force AG were not changed in this case. Thus the short – lived aging did not change the conditions of the thermoelastic martensite forming

La alquibla en al-Andalus y al-Magrib al-Aqsá

Scanning tunneling microscopy has been used to investigate the initial adsorption stage of Bi on Si(1 0 0) and Ge(1 0 0) surfaces at room temperature. The most favorable position for a Bi ad-dimer on both surfaces is the B-configuration (Bi ad-dimer positioned on-top of the substrate rows with its dimer bond aligned along the substrate dimer row direction). For Si(1 0 0) the A-type dimers (dimer bond aligned perpendicular to the substrate dimer row direction) occasionally rotate back and forth to a B-configuration. The diffusion rates of B-type and A-type dimers along the substrate row and the B–A, A–B rotations on Si(1 0 0) are extracted from an analysis of many sequences of STM images. Finally, it is shown that the presence of an attractive interaction between Bi ad-dimers (irrespective of their orientation) positioned on neighboring substrate dimer rows leads to the formation of local regions with a 2×2 reconstruction

The structure, phase and chemical composition of CZTSe thin films

Cu₂ZnSnSe₄ thin films obtained by co-evaporation of components using an electron beam evaporation system were investigated by scanning electron microscopy, X-ray analysis, PIXI and RBS methods. The analysis of the diffraction patterns showed that the films are almost single-phased and contain mainly CZTSe compound, which has a tetragonal kesterite lattice type. The samples have textural growth of [211]. The lattice parameters of the material varied in the range of a = (0.56640-0.56867) nm, c = (1.13466-1.13776) nm, c/2a = 0.9983-1.0017 which correlate well with the reference data in a stable phase CZTSe compounds. From our PIXE analyses we assessed the influence of the growth conditions on the samples chemical composition and mapped the surface distribution