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[en] The real sample temperatures during the nuclear resonant vibrational spectroscopy on biological samples have been assessed and significantly reduced (116 → 52 K) by improving the sample-loading procedures. There are several practical and intertangled issues which make the experiments of nuclear resonant vibrational spectroscopy (NRVS) on biological samples difficult to perform. The sample temperature is one of the most important issues. In NRVS the real sample temperatures can be very different from the readings on the temperature sensors. In this study the following have been performed: (i) citing and analyzing various existing NRVS data to assess the real sample temperatures during the NRVS measurements and to understand their trends with the samples’ loading conditions; (ii) designing several NRVS measurements with (Et_4N)[FeCl_4] to verify these trends; and (iii) proposing a new sample-loading procedure to achieve significantly lower real sample temperatures and to balance among the intertangled experimental issues in biological NRVS measurements
[en] The crystalline parameters α and c of the FeCl2 hexagonal cell have been measured by X-ray diffraction on a powdered specimen. Here we report the values of these parameters at 77 and 300 K, and also their thermal variations between 4.2 and 30 K. The relative variations a30-a4.2/a4.2 and c30-c4.2/c4.2 are (1.1±0.4) x 10-3 and -(7.2±0.6) x 10-4 respectively. When the temperature goes below the Neel temperature (TT≅23.8 K), the parameters a and c display different kinds of variations. This change is attributed to the magneto-elastic coupling and by using previous experimental data obtained on FeCl2 submitted to mechanical stresses, we determine the derivatives of the magnetic interactions (including crystalline field) versus the diagonal crystal strain tensor components. We estimate the value of the elastic constant C13 to be 1.6 erg/cm3. Moreover the experimental results at our disposal are sufficient for checking the magnetic studies of FeCl2 submitted to mechanical stresses
[en] Based on considerations of principles and experimental data, the interference of sulfate ions in poteniometric titration of EDTA with FeCl3 was confirmed. The method of back complexometric titration of molybdenum of Nonova and Gasheva was improved by replacing hydrazine sulfate with hydrazine hydrochloride for reduction of Mo(VI) to Mo(V). The method can be used for one to tenths of mg of molybdenum with 0.04 mg standard deviation. The specific method of determination of molybdenum in molybdenite concentrates is presented
[en] In this study, commercially available cellulose membranes were hybridized with conjugated polymer via vapor-phase polymerization using pyrrole and iron chloride as a monomer and oxidant, respectively. The iron (III) chloride layer dip-coated on the hydrophilic cell ulose surface oxidized the vaporized pyrrole monomer leading to the polypyrrole-cellulose hybrid membrane. The conductivity of hybrid membrane was optimized by varying the oxidant concentration and the monomer vapor exposure time. The various surface characterizations of polypyrrole-cellulose hybrid membrane show that the conductive polypyrrole layer was uniformly deposited onto the surface of cellulose fibrous networks unlike the polypyrrole-nylonhybrid membrane prepared in the similar way. The polypyrrole-incorporated cellulose networks exhibits steeper electrical conductance increase over the vertical pressure than its nylon counterpart. Our result suggests that the polypyrrole-cellulose hybrid membrane can be applicable for a disposable high-load pressure sensor.
[en] Direct chlorination of aluminum is part of the HALOX project, which deals with the halogenation of the sheaths of the spent fuel, consisting of an aluminum-based alloy. Iron is one of the important nuclear fuel elements from a radiological point of view, since after irradiation it converts to a radioactive isotope, 55Fe, which decays by electronic capture with a semi-disintegration period of 2.73 years. This work focuses on the reaction of the iron-aluminum binary alloys and of equivalent amounts of pure metals, with gaseous chlorine in order to study the interactions between them and the possibility of their separation. The chlorination was carried out in a flow of 2 liters/hour of gaseous chlorine and in a temperature range of 150oC to 300oC. The incidence of the thermal treatment temperatures on the characteristics of the chlorides that were formed was analyzed. The characterization techniques used were: energy dispersive spectroscopy (EDS) and x-ray diffraction (XRD). The structure's evolution was studied by sweep electronic microscopy (SEM), Given that the EDS only provides a semi-quantitative form of the composition and does not detect concentrations of elements below 1%, the products had to be quantified using such analytical techniques as: atomic absorption, spectrophotometry, gravimetry and volumetry (CW)
[en] Spent pickling liquor containing almost FeCl2 is a considered hazardous waste because of its very high level of acidity and high metal concentration, and the conventional neutralization method regenerates an excessive quantity of sludge that poses a serious problem concerning to the landfill disposal and risk of ground water contamination. Therefore, recovery of spent pickling liquor is necessary. Several approaches have been investigated for spent pickling liquor recovery, but they are generally costly and lead to produce various iron salts or oxides which have a limited value. In the present study, we explore the potential of using spent pickling liquor and FeCl2 solution as iron precursor for the synthesis of magnetic nanoparticles. Here, Fe3O4 nanoparticles were prepared easily by oxidation-precipitation from spent hydrochloride acid pickling liquors in aqueous saturated solution of calcium hydroxide at room temperature, in the air, and under suitable speed of rotation. The FT-IR, XRD and TEM results shown that monodisperse Fe3O4 nanoparticles in the size range of 10-40 nm were obtained, with a high level of crystalline. The BET surface area of particles from spent pickling liquor was about 46 m2g-1, and from FeCl2 salt was about 24 m2 g-1. The synthesized Fe3O4 nanoparticles exhibited the super paramagnetic behavior with relatively high saturation magnetization, from spent pickling liquor about Ms=73 emu g-1 and from FeCl2 salt was higher, about 83 emu g-1. The tested adsorbed capacity of As (V) of particles from spent pickling liquor was about 90 mg As/g Fe3O4, and from FeCl2 salt was about 42 mg As/g Fe3O4. This proves that some impurities in the pickling solution such as Mn, C ... help to develop the surface and adsorption capacity. (author)
[en] The bulk Si-O-C ceramics were prepared by polymer derived ceramics (PDCs) route using polysiloxane as precursor and their properties were investigated for electromagnetic wave absorbing in the frequency range of 12.4–18 GHz (Ku-band). It was found that the catalytic pyrolysis can enhance substantially the absorbing properties by in situ formation of turbostratic carbon network, ordered carbon, and multi-wall carbon nanotubes. The matching thickness of sample containing 1.5 wt% FeCl3 (FPSO-1.5) is 2.2 mm, and its reflection loss exceeds −10 dB in the whole Ku-band with an absorption peak of −35.48 dB at 14.16 GHz. For sample containing 1.5 wt% FeCl3, its absorption peak increases to −15.78 dB, but its matching thickness decreases significantly to 2.2 mm. The polymer derived Si-O-C ceramics could be used as excellent electromagnetic functional devices working in harsh environments. (paper)
[en] We report magnetization measurements on ferric chloride intercalated graphite in the temperature range for stages of index n=1–6 and 8. All stages exhibit a sharp increase in M(T) at as the temperature decreases and a subsequent saturation below 1.4 K. The saturation magnetization, when normalized to the iron contents, exhibits a strong stage dependence ), up to stage 5 and then deviates for higher stages. For the stage 6 sample has a linear dependence on the trapped applied field and long relaxation times ranging from under one to more than 4 min. The relaxation time τ(T) has a lambda shape with a peak temperature of 1.45 K, with similar results for stage 3.
[en] Ferric chloride has been found to induce a significant synergistic enhancement of the extraction of trivalent lanthanides and actinides by tetra(n-octyl)diglycolamide (TODGA) from acidic chloride media. In this manuscript, results of a thorough investigation of the TODGA-HCl-Fe(III) system using solvent-extraction experiments designed to elucidate the stoichiometry of the synergistic species will be described. Results for Ac(III), Am(III), Eu(III), Pm(III), Y(III), Th(IV), Pu(IV), and U(VI) will be discussed. (authors)