A Mössbauer cryostat equipped with a Gifford McMahon cryocooler

1989

A new cryostat for Mossbauer spectroscopic measurements has been developed around a cryogenerator of the Gifford McMahon type operating with helium gas in a closed circuit. Both source and absorber can be cooled to about 30K and the unwanted vibrations caused by the helium compression/expansion cycle have been limited to approximately 0.05–0.06 mms−1.

Antimony-121 Mössbauer spectra of organoantimony derivatives containing Sb-Sb bonds

1994

121-Sb Mossbauer data are reported for a number of organoantimony rings and catena-stibanes. These compounds are representative of RSb(Sb)2 and R2SbSb type of coordination, and spectral parameters are compared and discussed in relation to RSbCl2 and R2SbCl systems. Although the trend in isomer shift is similar, the present compounds show slightly less negative isomer shift values together with a remarkable reduction of the quadrupolar coupling constant. A rationalization of the quadrupolar interaction in the above series of compounds appears feasible by using point charge model calculations whose results, in terms of bonding, indicate a large contribution of p-electron density along Sb-Sb b…

Rare earth elements distribution in seawater and suspended particulate of the Central Mediterranean Sea

2004

Rare earth element (REE) content in suspended and dissolved phases from the Strait of Sicily (Central Mediterranean Sea) has been measured. Vertical profiles of several dissolved REEs along the water column reflect the 3-D oceanographic features of the studied area and identifies the different water masses present there. Shale-normalized REE distribution patterns and derived parameters calculated for the suspended particulate show different atmospheric dust-surface inputs and their interactions with seawater. Finally, combined information from [La/Yb]N, ratios, REE/La ratios and Eu anomalies measured in the suspended particulate suggest an important contribution of volcanic materials from t…

Thermodynamic and19F NMR studies of antimony trifluoride in water

1993

Densities, specific heat capacities per unit volume and enthalpies of dilution at 25°C and osmotic coefficients at 37°C were measured for antimony trifluoride in water as functions of concentration. From the first three properties the apparent and partial molar volumes, heat capacities and relative enthalpies were derived. As well, pH measurements in water at 25°C and19F NMR spectra in water and methanol at 33°C were also carried out. All the thermodynamic properties together with the chemical shifts abruptly change in the very dilute concentration region (<0.1m) and, then, tend to a constant value. These trends have been rationalized through a simple model based on an equilibrium of dissoc…

Dielectric properties of solutions of antimony (III) halides in methanol

1993

The complex permittivities obtained by time domain reflectometry (TDR) measurements in the frequency range 0.1–15 GHz are reported for solutions of SbF3, SbCl3 and SbBr3 in methanol at 25°C. By increasing the concentration of the solutes, a marked increase of the main relaxation time and of the static permittivity of methanol is observed. These effects have been attributed to the ability of antimony (III) halides to strengthen the hydrogen bonding in methanol and to promote the shift of the dynamic equilibria among the various populations of hydrogen bonded methanol aggregates toward those characterized by a parallel orientation of neighboring dipoles. A second relaxation, occurring at low …

On the metal distribution in the system GeTe−Sb2Te3

1988

The structures of GeSb2Te4, Ge2Sb2Te5 and GeSb4Te7 are not determined completely by means of classical X-ray or electron diffraction studies. We have measured the Mossbauer parameters of121Sb in these compounds as well as in their binary constituent Sb2Te3 as an attempt to improve our knowledge on the question.

Studies on antimony trifluoride in thiocyanate salt matrices. Evidence for the formation of fluoro-thiocyanato anti-mony(III) species

1990

Abstract Antimony trifluoride can be dissolved in fused KNCS or NH4NCS giving yellow-orange solutions which are stable only for a short time just above their melting point. Infrared an Mossbauer results on solidified samples reveal the formation of mixed fluoro-thiocyanato antimony(III) species and indicate a different behaviour in the two matrices.

Technology for plant food support in Antarctica

2011

Isolation of organophosphorus-degrading bacteria from agricultural mediterranean soils

2010

SUPRAMOLECULAR ORGANIZATION OF TRIGLYCERIDES IN EXTRA-VIRGIN OLIVE OILS AS ASSESSED BY NMR RELAXOMETRY

2010

Low resolution nuclear magnetic resonance (NMR) relaxometry revealed that triglycerides in extra-virgin olive oils are organized in inverse-micelle-like supramolecular structures held together by weak interactions such as van der Waals and hydrogen bonding. The formers can be established among the external apolar tails, while hydrogen bonds are present among the internal polar triglyceride heads, involving also the polar minor constituents of extra- virgin olive oils. The supramolecular assembly has been supported by experiments conducted by heating the samples in the NMR probe at four different temperatures. In addition all the oils were also added with increasing amounts of glacial acetic…

Effects of pyrolysis conditions on the thermal transformation of chicken manure into char

2012

Biochar is a fine-grained and highly porous carbonaceous substance, arising from the pyrolitic decomposition of natural or synthetic organic materials. It is lately applied to soils to favorably affect soil physico-chemical properties, such as water and nutrient retention and cation exchange capacity (CEC). The extent of the effect of biochar on crop productivity is very variable due to the different biophysical interactions and processes that occur when it is applied to soils. Char properties are greatly influenced by both natures of feedstock and process conditions. An accurate characterization of biochar is crucial to evaluate the possibility to amend soil with such material by avoiding …

Applications and New Developments of Magnetic Resonance Techniques in Soil Science

2010

HS-SPME and GC-MS as valid tools to assess volatile organic compounds from soil natural organic matter

2008

Solid state NMR spectroscopy in the evaluation of the conformational changes of humic substances as affected by thermal variations

2009

BIOCHAR SURFACE PROPERTIES THROUGH APPLICATION OF AN INNOVATIVE NMR TECHNIQUE: FAST FIELD CYCLING RELAXOMETRY

2013

Biochar is a carbonaceous material obtained by pyrolysis of biomass feedstocks. It is applied to soils in order to improve fertility and mitigate greenhouse-gases emissions. In fact, from the one hand, biochar changes physical-chemical soil properties, thereby affecting soil fertility. From the other hand, biochar is resistant to chemical and biochemical degradation. For this reason, its use allows carbon sequestration in soils and consequent reduction of carbon dioxide to the atmosphere. Here, dynamics of water at the liquid-solid interface of water saturated biochars is discussed. Results revealed that water dynamics is affected by the nature of biochar parent biomasses. Moreover, biochar…

CCDC 152558: Experimental Crystal Structure Determination

2001

Related Article: F.Benetollo, G.Bombieri, A.Del Pra, G.Alonzo, N.Bertazzi|2001|Inorg.Chim.Acta|319|49|doi:10.1016/S0020-1693(01)00436-4

CCDC 152559: Experimental Crystal Structure Determination

2001

Related Article: F.Benetollo, G.Bombieri, A.Del Pra, G.Alonzo, N.Bertazzi|2001|Inorg.Chim.Acta|319|49|doi:10.1016/S0020-1693(01)00436-4

CCDC 152557: Experimental Crystal Structure Determination

2001

Related Article: F.Benetollo, G.Bombieri, A.Del Pra, G.Alonzo, N.Bertazzi|2001|Inorg.Chim.Acta|319|49|doi:10.1016/S0020-1693(01)00436-4