An investigation of structural, thermal, and electrical conductivity properties for understanding transport mechanisms of CuWO4 and α-CuMoO4 compounds.

Recently, inorganic oxide components with high ionic conductivity have been widely explored due to their high stability, safety, and energy density properties. In this context, the present work focuses on the inorganic oxides CuMO4 (M = W, Mo), which have been successfully synthesized using the traditional solid-state method. They were characterized by X-ray powder diffraction, thermal analysis, and complex impedance spectroscopy. X-ray diffraction data refined via the Rietveld method indicated that these compounds are well crystallized in the triclinic system with the P1̄ space group. Besides, the electrical conductivity behavior of these materials was analyzed using the impedance spectroscopy technique in the frequency range of 100 to 106 Hz and in the temperature range of 443 K to 563 K. The absence of a phase transition observed in the calorimetric study was confirmed by the σg and ωh variations as a function of temperature. The AC conductivity was analyzed by Jonscher's power law. The outcomes of the study on charge transportation in CuMO4 (where M = W, Mo) suggest that the overlapping large polaron tunneling (OLPT) mechanism was present in CuMoO4, while the correlated barrier hopping (CBH) and the non-overlapping small polaron tunneling (NSPT) were present in CuWO4. A correlation between the crystal structure and the ionic conductivity was established and discussed. For the two title compounds, modulus analysis revealed that the charge carriers were mobile over short and long distances at low and high frequencies, respectively. The temperature variation of the M'' peak showed a thermally activated relaxation process.

Optical and dielectric properties of NaCoPO4 in the three phases α, ß and γ.

In this work, we are interested in the synthesis of monophosphate α-NaCoPO4, ß-NaCoPO4 and γ-NaCoPO4 compounds by mechanochemical method and their characterization by X-ray powder diffraction patterns. These compounds are crystallized in the orthorhombic, hexagonal and monoclinic system, in Pnma, P65 and P21/n space groups, respectively. The optical properties were measured by means of the UV-vis absorption spectrometry in order to deduce the absorption coefficient α and optical band gap E g. The calculated values of the indirect band gaps (E gi) for three samples were estimated at 4.71 eV, 4.63 eV and 3.8 for compounds α, ß and γ, respectively. The Tauc model was used to determine the optical gap energy of the synthesized compounds. Then, the results of the dielectric proprieties measured by varying the frequency are described.

Vibrational study of [(CH3)4N]2Cu0.5Zn0.5Cl4.

[(CH3)4N]2Zn0.5Cu0.5Cl4 shows an orthorhombic system at ambient temperature with P2(1)nb space group. At room temperature, the crystal consists of three sublattices constituted by MCl4 (M=Cu and Zn) and two tetramethylammoniums N1(CH3)4 and N2(CH3)4, which give rise to a total of 372 vibrational modes that transform according to the four irreductible representations of the C2v point group in the following way: Gamma(vib)=93(A1+A2+B1+B2). The infrared and Raman spectra of polycrystalline samples have been investigated at room temperature. The assignment of the observed bands is discussed.

[Pharmacokinetics of lidocaine and bupivacaine after peribulbar block with additional hyaluronidase]. / Pharmacocinétique de la lidocaïne et de la bupivacaïne après bloc péribulbaire avec adjonction d'hyaluronidase.

OBJECTIVE: To assess the time course of plasma concentrations of lidocaine and bupivacaine associated with hyaluronidase for peribulbar block. STUDY DESIGN: Prospective study. PATIENTS: Ten patients (mean age = 71 +/- 11 yrs, mean weight 63 +/- 10 kg) scheduled for cataract surgery with lens implantation. METHOD: Lidocaine 2% (5.5 mL = 110 mg) and bupivacaine 0.5% (5.5 mL = 27.5 mg) associated with hyaluronidase (80 IU) were injected supra and infra-orbitally, in patients premedicated with midazolam. Blood samples wer0 collected at constant time intervals from the end of infiltration until the 6th hour. The plasma concentrations of local anesthetics were measured with the HPLC technique. RESULTS: The median plasma peak concentration was 1.74 mg.L-1 after 10 min for lidocaine, and 0.52 mg.L-1 after 7.5 min for bupivacaine respectively. CONCLUSIONS: The similar delays of occurrence of peak concentrations confirm that liposolubility is not the only factor of diffusion of local anaesthetics from the periocular fat into the blood stream. The peak concentrations are far below the alleged toxic concentrations. When associated with hyaluronidase, the peak concentrations occur as rapidly as after endotracheal or paracervical administration.