A Mössbauer study of organotellurium compounds. Part I

1976 ◽  
Vol 54 (20) ◽  
pp. 3234-3241 ◽  
Author(s):  
Colin H. W. Jones ◽  
Robert Schultz ◽  
William R. McWhinnie ◽  
Nigel S. Dance
Keyword(s):  
Additive Model ◽  
Mössbauer Study ◽  
Wide Range ◽  
Mössbauer Data ◽  
Organotellurium Compounds

Mössbauer data for a wide range of organotellurium compounds are reported, including compounds of the type: R2Te, Ar2Te, Ar2Te2, R2TeX2, Ar2TeX2, and ArTeX3; where R = alkyl, Ar = aryl, and X = Cl, Br, or I. The isomer shifts and quadrupole splittings are interpreted in terms of the relative populations of the tellurium 5s and 5p orbitals. The quadrupole splittings are rationalized in terms of a simple additive model, formulated within the framework of the Townes and Dailey theory.

A Mössbauer study of organotellurium compounds. Part III. Tellurium heterocycles and related compounds

1978 ◽  
Vol 56 (13) ◽  
pp. 1746-1751 ◽  
Author(s):  
Nigel S. Dance ◽  
Colin H. W. Jones
Keyword(s):  
Heterocyclic Compounds ◽  
Mössbauer Study ◽  
Ring Systems ◽  
Mössbauer Parameters ◽  
Mössbauer Data ◽  
Related Compounds ◽  
Organotellurium Compounds

Mössbauer data are reported for a number of heterocyclic compounds containing tellurium. The influence on the Mössbauer parameters of the constraints imposed by accommodating tellurium in these ring systems are discussed. The influence of the bulky aryl ligand 2-biphenylyl, C12H9—, on the Mössbauer parameters of diaryltellurium dihalides and aryltellurium trihalides has also been investigated.

An 129I Mössbauer study of organotin iodides

1981 ◽  
Vol 59 (11) ◽  
pp. 1585-1591 ◽  
Author(s):  
C. H. W. Jones ◽  
M. Dombsky
Keyword(s):  
Solid State ◽  
Additive Model ◽  
Mössbauer Study ◽  
Tetrahedral Geometry ◽  
Mössbauer Data

Iodine-129 Mössbauer data for SnI4, MeSnI3, Me2SnI2, Me3SnI, Me3SnI2−, Me3SnI.py, and Me2SnI2.2py are reported. The data are compared with available nqr data for the corresponding chlorides and bromides. The Mössbauer data are interpreted as evidence that MeSnI3, Me2SnI2, and Me3SnI are distorted from tetrahedral geometry in the solid state. The applicability of the additive model in interpreting 119Sn quadrupole splittings in these compounds is commented on.

A Mössbauer study of organotellurium compounds. Part II. Halides, acetates, and benzoates

1976 ◽  
Vol 54 (23) ◽  
pp. 3737-3742 ◽  
Author(s):  
Frank J. Berry ◽  
Colin H. W. Jones
Keyword(s):  
The Other ◽  
Mössbauer Study ◽  
Mössbauer Data ◽  
Organotellurium Compounds

125Te Mössbauer data, measured at 4.2 K, are reported for a number of organotellurium(IV) compounds, including Ar2TeF2, ArTeF3, Ar2Te(OCOCH3)2, Ar2Te(OCOC6H5)2, where Ar = Ph, p-EtOC6H4, p-MeOC6H4, p-C7H7, and the compounds Ph2(CH3)TeI and Ph(CH3)2TeI. Evidence is presented that while the difluorides appear to be similar in structure to the other dihalides(X = Cl, Br, I), in the trifluorides the co-ordination about the tellurium is significantly different to that found in the other trihalides (X = Cl, Br, I). The iodides studied have parameters consistent with their formulation as Ph2(CH3)Te+I− and Ph(CH3)2Te+I−. The dicarboxylates have parameters similar to those of the dihalides, although the diphenyl tellurium diacetate and dibenzoate have relatively small Δ's in comparison with those of the other derivatives studied and it would appear that subtle changes in the co-ordination about tellurium occur with changes in the aryl ligand.

scholarly journals Environmental Drivers and Age Trends in Site Productivity for Oak in Southern Poland

Forests ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 209
Author(s):  
Luiza Tymińska-Czabańska ◽  
Jarosław Socha ◽  
Marek Maj ◽  
Dominika Cywicka ◽  
Xo Viet Hoang Duong
Keyword(s):  
Nitrogen Deposition ◽  
Management Practices ◽  
Additive Model ◽  
Climatic Conditions ◽  
Environmental Indicators ◽  
Environmental Drivers ◽  
Site Productivity ◽  
Site Factors ◽  
Wide Range ◽  
Si Model

Site productivity provides critical information for forest management practices and is a fundamental measure in forestry. It is determined using site index (SI) models, which are developed using two primary groups of methods, namely, phytocentric (plant-based) or geocentric (earth-based). Geocentric methods allow for direct site growth modelling, in which the SI is predicted using multiple environmental indicators. However, changes in non-static site factors—particularly nitrogen deposition and rising CO2 concentration—lead to an increase in site productivity, which may be visible as an age trend in the SI. In this study, we developed a geocentric SI model for oak. For the development of the SI model, we used data from 150 sample plots, representing a wide range of local topographic and site conditions. A generalized additive model was used to model site productivity. We found that the oak SI depended predominantly on physicochemical soil properties—mainly nitrogen, carbon, sand, and clay content. Additionally, the oak SI value was found to be slightly shaped by the topography, especially by altitude above sea level, and topographic position. We also detected a significant relationship between the SI and the age of oak stands, indicating the long-term increasing site productivity for oak, most likely caused by nitrogen deposition and changes in climatic conditions. The developed geocentric site productivity model for oak explained 77.2% of the SI variation.

scholarly journals Augmentative Modelling: A Template for Populus spp. Stand Biomass in Eurasia Region

2020 ◽  
Vol 24 (5) ◽  
pp. 827-832
Author(s):  
Andreevich Usoltsev Vladimir ◽  
Omid Reza Shobairi Seyed ◽  
Stepanovich Tsepordey Ivan ◽  
Petrovich Chasovskikh Viktor
Keyword(s):  
Additive Model ◽  
Component Composition ◽  
Generic Model ◽  
Total Biomass ◽  
Biological Productivity ◽  
Local Conditions ◽  
Component Structure ◽  
Allometric Models ◽  
Wide Range ◽  
Populus Spp

Today, estimating of biological productivity or carbon-depositing ability of forests is going on the global level, and its increase is one of the major factors of climate stabilization. In recent years, two trends in the harmonization of allometric models of tree biomass have been developing. The  first of them is related to ensuring the additivity of the biomass component composition, and the second one – to the search for the so-called generic model applicable to a wide range of environmental conditions. However, all "generic" models give significant biases in their application in local conditions. In our modeling, we adhere to the principle of biomass additivity, split "generic" model into regional variants by introducing dummy variables, and build the model at the transcontinental level for the first time. When using the unique in terms of the volume of database on the level of stand of the genus Populus spp. in a number of 212 sample plots, the trans-Eurasian additive allometric models of biomass of standsfor Eurasian Populus forests are developed, and thereby the combined problem of model additivity and generality is solved. The additive model of forest biomass of Populus is harmonized in two ways: it eliminated the internal contradictions of the component and the total biomass equations, and in addition, it takes into account regional differences of forest stands not only on total, aboveground and underground biomass, but also on its component structure, i.e. it reflects the regional peculiarities of the component structure of biomass. Keywords: genus Populus spp., biomass of forests, allometric models, sample plots, biological productivity

57Fe and 125Te Mossbauer Study of LiFeCo3TeO8 and LiFeNi3TeO8

1980 ◽  
Vol 3 ◽  
Author(s):  
Andre Gerard ◽  
Fernande Grandjean ◽  
Carlo Flebus
Keyword(s):  
Structural Information ◽  
Magnetic Hyperfine ◽  
Hyperfine Fields ◽  
Mössbauer Study ◽  
Mössbauer Data

ABSTRACT57 Fe and 125 Te Mössbauer data on the spinels LiFeNi3TeO8 and LiFeCo3TeO8 are presented. Structural information relating to site occupations by Fe, valency of Fe and Te and magnetic hyperfine fields are obtained from this study.

scholarly journals CIRRUS REMOVAL IN MULTISPECTRAL DATAWITHOUT 1.38μM SPECTRAL DATA

2016 ◽  
Vol III-7 ◽  
pp. 41-44
Author(s):  
Aliaksei Makarau ◽  
Rudolf Richter ◽  
Viktoria Zekoll ◽  
Peter Reinartz
Keyword(s):  
Additive Model ◽  
Optical Data ◽  
Landsat 8 ◽  
Cirrus Cloud ◽  
Landsat 8 Oli ◽  
Spectral Channel ◽  
Wide Range ◽  
Low Altitude ◽  
Spectral Channels ◽  
Sentinel 2

Cirrus is one of the most common artifacts in the remotely sensed optical data. Contrary to the low altitude (1-3 km) cloud the cirrus cloud (8-20 km) is semitransparent and the extinction (cirrus influence) of the upward reflected solar radiance can be compensated. The widely employed and almost ’de-facto’ method for cirrus compensation is based on the 1.38μm spectral channel measuring the upwelling radiance reflected by the cirrus cloud. The knowledge on the cirrus spatial distribution allows to estimate the per spectral channel cirrus attenuation and to compensate the spectral channels. A wide range of existing and expected sensors have no 1.38μm spectral channel. These sensors data can be corrected by the recently developed haze/cirrus removal method. The additive model of the estimated cirrus thickness map (CTM) is applicable for cirrus-conditioned extinction compensation. Numeric and statistic evaluation of the CTM-based cirrus removal on more than 80 Landsat-8 OLI and 30 Sentinel-2 scenes demonstrates a close agreement with the 1.38μm channel based cirrus removal.

Stock Price Modeling: Separation of Trend and Fluctuations, and Implications

2015 ◽  
Vol 18 (04) ◽  
pp. 1550027 ◽  
Author(s):  
B. D. Craven ◽  
Sardar M. N. Islam
Keyword(s):  
Behavioral Finance ◽  
Positive Feedback ◽  
Stock Prices ◽  
Stock Price ◽  
Additive Model ◽  
Logarithmic Scale ◽  
Price Behavior ◽  
Interaction Terms ◽  
Wide Range ◽  
Short Time

A series of stock prices typically shows a large trend and smaller fluctuations. These two parts are often studied together, as if parts of a single process; but they appear to be separately caused. In this paper, the two parts are analyzed separately, so that one does not distort the other, and some spurious interaction terms are avoided. This contributes a model, in which a wide range of features of stock price behavior are identified. With logarithms of stock prices, the two parts become of more comparable size. This is found to lead to a simpler additive model. On a logarithmic scale, the stock prices show the trend as a straight line (which can be extrapolated), with added fluctuations filling a narrow band. The trend and fluctuations are thus separated. The trend appears to be largely generated by a positive feedback process, describing investor behavior. The width of the fluctuation band does not grow with time, so positive feedback is not its cause. The movement of stock prices can be understood by analyzing the trend and fluctuations as separate processes; the latter considered as a stationary stochastic process with a scale factor. This analysis is applied to a historical dataset [Formula: see text] index of daily prices from February 1928). Here, the fluctuations are autocorrelated over short time intervals; there is little structure, except for market crash periods, when variability increases. The slope of the trend showed some jumps, not predictable from price history. This approach to modeling describes many aspects of stock price behavior, which are usually discussed in behavioral finance.

Mixed oxidation state compounds of antimony: a 121Sb Mössbauer study of some antimony–fluorine systems

1978 ◽  
Vol 56 (18) ◽  
pp. 2417-2421 ◽  
Author(s):  
Jack G. Ballard ◽  
Thomas Birchall ◽  
Ronald J. Gillespie ◽  
Edward Maharajh ◽  
David Tyrer ◽  
...  
Keyword(s):  
Oxidation State ◽  
Mössbauer Spectra ◽  
Mössbauer Study ◽  
Mossbauer Spectra ◽  
Mixed Oxidation ◽  
Mössbauer Data

Antimony-121 Mössbauer spectra for [Sb2F42+][SbF6−]2 and three compounds containing the [Sb3F14−] ion are reported. The Mössbauer data are discussed in relation to their known structures. Two of the compounds give spectra which, on analysis, give η values of unity.

scholarly journals Mössbauer study of iron gall inks on historical documents

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
A. Lerf ◽  
F. E. Wagner ◽  
M. Dreher ◽  
T. Espejo ◽  
J.-L. Pérez-Rodríguez
Keyword(s):  
Middle Ages ◽  
Degradation Products ◽  
Gum Arabic ◽  
Experimental Methods ◽  
Western World ◽  
Historical Documents ◽  
Mössbauer Study ◽  
Mössbauer Data ◽  
Iron Gall ◽  
Forms Of Iron

AbstractIron gall ink was used in the Western world as a permanent writing material already in late Roman times and throughout the Middle Ages, until it became obsolete in the twentieth century. There is much interest in experimental methods to determine the state of the ink and its degradation products on historical documents. Mössbauer spectroscopy with 57Fe is such a method, and it has the particular advantage to be sensitive to the chemical bonding of iron, but this method has only rarely been applied to historical documents. In this paper we present Mössbauer data for two damaged documents from a Library in Granada and a handwritten German book from the eighteenth century. In addition to the inked parts of the manuscripts, ink-free parts were studied to determine the amount and chemical state of the iron in the papers. These new results are discussed in the context of previously published Mössbauer data. In one of the investigated documents Fe(II)-oxalate, FeC2O4·2H2O, was observed. The assignment of the various Fe3+ sites in the different documents is rather difficult and often there is a superposition of various species. Known forms of iron gallate are definitely not present on the inked papers. The observed ferric species can be remains of Fe3+ polyphenol complexes of the ink, complexes of Fe3+ with degradation products of the cellulose of the paper or gum arabic, or very small iron oxide or hydroxide nanoparticles.

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