Biocompatibility of the Ti<Subscript>81</Subscript>Nb<Subscript>13</Subscript>Ta<Subscript>3</Subscript>Zr<Subscript>3</Subscript> Alloy

Titanium-based alloy with low-toxic metals such as niobium, tantalum and zirconium (TiNbTaZr) was manufactured. The primary weight percentages of elements used for fusion were: titanium, 65%; niobium, 20%, tantalum, 10%; and zirconium, 5%. The TiNbTaZr alloy had a yield strength of about 550 MPa, a tensile strength of about 700 MPa, and a Young’s modulus of about 50 GPa, that is, it was comparable with Nitinol. A primary study of the biocompatibility of the TiNbTaZr alloy using the SH-SY5Y cells showed that the alloy did not have significant short-term toxicicity towards the cells incubated on the alloy surface. The number of non-viable cells was 2.5 times lower on the TiNbTaZr alloy than on Nitinol. The biocompatibility of TiNbTaZr was more pronounced than that of the Nitinol reference sample.     

Low temperature thermodynamic properties of Gd<Subscript>2</Subscript>SrCo<Subscript>2</Subscript>O<Subscript>7</Subscript>

Summary Thermodynamic properties of a layered perovskite oxide Gd₂SrCo₂O₇ have been studied. Powder X-ray diffraction, electric resistivity, magnetic susceptibility and heat capacity measurements were carried out. The crystal structure was determined as I4/mmm. The temperature dependence of the magnetic susceptibility was fitted to the Curie-Weiss behavior with antiferromagnetic interaction. Spin state of Co³⁺ ion was derived to be intermediate spin state configuration (t_2g⁵e_g¹). The spin ordering was observed as a broad anomaly in the heat capacity curve with a peak at 2 K. The measured entropy was 35.47 J K^-1mol^-1, which was 65% of expected value. Thus the spin ordering should not be completed at the lowest temperature 0.2 K covered in the present experiments and/or some short range ordering remains at higher temperatures.     

Synthesis of new <Emphasis Type="Italic">N</Emphasis>-aminoglycosides based on halo-substituted <Emphasis Type="Italic">p</Emphasis>-phenylenediamines and <Emphasis Type="Italic">p</Emphasis>-aminophenols

Condensation of the monosaccharides D-glucose and D-galactose with synthesized halo-substituted p-phenylenediamines and 4-amino-2,6-dibromophenol was studied. It was found that glycosylation occurred only at the 4-amino group that was sterically unhindered by the halogen atom. The position of the aglycon in the glycoside was established by PMR spectroscopy.     

Interaction of components in the Tl<Subscript>2</Subscript>Se-Tl<Subscript>4</Subscript>SnSe<Subscript>4</Subscript>-Tl<Subscript>9</Subscript>SbSe<Subscript>6</Subscript> quasi-ternary system

The interaction in the Tl₂Se-Tl₄SnSe₄-Tl₉SbSe₆ quasi-ternary system was studied by differential thermal analysis, X-ray powder diffraction analysis, and mathematical modeling. The projection of the liquidus surface and a spatial phase diagram of the system were constructed. It was determined that this system is of the eutectic type with boundary solid solutions based on the initial components. No formation of new intermediate compounds in the quasi-ternary system was detected.     

Electronic energy structure of Al<Subscript>x</Subscript>Si<Subscript>1−<Emphasis Type="Italic">x</Emphasis></Subscript>C wide-gap semiconductor crystals

The electronic structure of silicon carbide solid solutions with aluminum has been studied within the limits of a single approximation. The local coherent potential method in terms of multiple scattering theory was used. The electronic spectrum was analyzed in comparison with the experimental X-ray spectra of silicon, aluminum, and carbon. The nature of the observed features of the electronic spectrum is interpreted, and Al-Si covalent binding in solid solutions is found. Formation of vacant states with energies of 1 Ry and decreased forbidden gap in the XANES spectrum at higher aluminum contents in crystal are discussed.     

The La(CCl<Subscript>3</Subscript>COO)<Subscript>3</Subscript>-NaCCl<Subscript>3</Subscript>COO-H<Subscript>2</Subscript>O system at 298 K

The ternary lanthanum trichloroacetate-sodium trichloroacetate-water system was studied by the isothermal solubility method at 298 K. The compositions of solid phases were established by the Schkreinemakers’ wet residue method. The liquid refractive indexes, specific volumes, and viscosities were determined. The system was found to be eutonic.     

Oxygen dependence of NO adsorption on Hollandite-type K<Subscript>x</Subscript>Ga<Subscript>x</Subscript>Sn<Subscript>8–<Emphasis Type="Italic">x</Emphasis></Subscript>O<Subscript>16</Subscript> thin film

Thin films of hollandite-type K_1.9Ga_1.9Sn_6.1O₁₆ (KGSO) were prepared by a spin-coating method. The films were colorless and transparent, 100-150 nm thick, and consisted of KGSO fine particles of about 20 nm in average size. The adsorption behavior of NO on the KGSO surface was examined by diffuse reflectance infrared fourier transform (DRIFTS). The KGSO was preheated at 968 K in a gas mixture of N₂ and O₂ prior to NO adsorption. As the oxygen ratio in the gas mixture increased up to 40%, absorption bands emerged and became stronger around 1400 cm^-1. Those bands were assigned to NO₂ species in chelating and nitrito form. It was found that the coexistence of oxygen remarkably improves the adsorption ability of NO on KGSO surface.     

Oxygen redistribution in ZrO<Subscript>2</Subscript>-Y<Subscript>2</Subscript>O<Subscript>3</Subscript> system

This work represents the results of oxygen redistribution studies at quantitative and isotopic levels in synthesis and thermal treatment of ZrO - (0 to 35 mol %) Y₂O₃ solid solution crystals. The crystals were grown by directed melt crystallization method in a cold container using direct high-frequency heating. The crystal oxygen content and isotopic composition data was collected with respect to stabilizer concentration and technological conditions of synthesis. The temperature and frequency relationships of crystal electroconductivity were also studied. Some strength and tribological characteristics of the given materials were represented. The solid state formation by directional melt crystallization was shown to involve oxygen isotopic exchange interaction between the melt, growing crystal, and gas phase.     

<Emphasis Type="Italic">P. psyllium</Emphasis>-<Emphasis Type="Italic">g</Emphasis>-polyacrylonitrile: synthesis and characterization

P. psyllium mucilage, an anionic natural polysaccharide consisting of pentosan and uronic acid obtained from the seeds of Plantago psyllium (Plantago family), was grafted with acrylonitrile (AN). Graft copolymers were prepared by grafting acrylonitrile onto P. psyllium mucilage (PSY) using ceric ion initiated solution polymerization technique for the very first time. The influence of varying concentration of (AN) and ceric ammonium nitrate (CAN) on graft copolymerization was studied. The percent grafting was found to be affected by the concentrations of AN and CAN in the reaction mixture. The prepared copolymers were not soluble in any common solvent or mixture of solvents. The prepared copolymers were characterized by FTIR.     

Phases in the system Tb<Subscript>2</Subscript>O<Subscript>3</Subscript>-SeO<Subscript>2</Subscript>-H<Subscript>2</Subscript>O at 100°C and their physicochemical study

Summary The solubility isotherm of the system Tb₂O₃-SeO₂-H₂O at 100° was studied. The compounds of the three-component system were identified by the Schreinemakers’ method as well as by chemical and X-ray phase analyses. Simultaneous TG and DTA analyses of all compounds of the system were made. The mechanism of thermal decomposition was described.     

Methyl 2‐hydroxy‐2‐[5′‐hydroxy‐5′‐(1‐hydroxy‐1‐methyl­ethyl)‐5,2′‐di­methyl­per­hydro‐2,2′‐bi­furan­yl‐5‐yl]­acetate

The relative configuration was determined for the title compound, C₁₆H₂₈O₇, which was obtained as a mixture of epimers. There are both intra‐ and intermolecular hydrogen bonds, the latter forming dimers around the crystallographic centres of inversion.     

Glycolipids from Leaves of <Emphasis Type="Italic">Eminium Lehmanii</Emphasis>

The quantitative composition of glycolipids from leaves of Eminium Lehmanii (Araceae) was established. It was shown that the predominant glycolipids were monogalactosyldiglycerides and digalactosyldiglycerides. The fatty-acid compositions of six glycolipids, of which digalactosyldiglycerides and sterylglycoside esters contained greater than 70% linoleic acid, were determined by GC. The main carbohydrate component of the leaf glycolipids was galactose. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 409–410, September–October, 2005.     

Modeling and optimizing toughness and rigidity of PA6/SBR: Using compatibilizer and response surface methodology

The improvement of miscibility between toughened Polyamide-6 (PA6) and Styrene-Butadiene Rubber (SBR) was carried out using grafted Glycidyl Methacrylate (SBR-g-GMA). At first, the compatibilizers were prepared using different comonomers, Styrene, and N-vinyl pyrrolidone. Central composited design (CCD) was distinctly applied to study the influence of Glycidyl Methacrylate (GMA) content and comonomer/GMA on the process of compatibilizer preparation. Four models were developed for Gel content and Degree of grafting for both comonomers using Design-expert software. The models were used to calculate the optimum operating conditions and according to the Flory-Huggins parameter and obtained results, SBR-co-NVP-g-GMA was chosen as an effective compatibilizer. Afterward, another CCD was employed to scrutinize the effect of various amounts and grafting degree of compatibilizer on morphology and mechanical properties of PA6/SBR. The Interparticle distance and polydispersity were studied using a Scanning electron microscope (SEM) and also the Izod impact test inspected in order to evaluate the mechanical properties. Finally, modulus and impact strength were optimized to minimize the former and maximize the latter. Also, the most practical terms in the fitted model are statistically specified using F-value. The root causes for the improvement of blend properties were attributed to a chemical reaction between epoxy groups in SBR-g-GMA and both the carboxylic and amine groups in PA6. Impact strength (539.8 J/m) and modulus (2017.2 N/mm²) of the optimum blend indicate an excellent agreement with the amounts predicted by the models.     

Synthesis of dense ceramics of single-phase mayenite (Ca<Subscript>12</Subscript>Al<Subscript>14</Subscript>O<Subscript>32</Subscript>)O

The nanoporous material mayenite was synthesized by two methods: solid-phase and self-propagating high-temperature (combusting) (SHS) syntheses. The structure of the materials was determined by the X-ray diffraction analysis and IR and Raman spectroscopy.     

Syntheses proceeding from <Emphasis Type="Italic">N</Emphasis>-(oxiran-2-ylmethyl)-<Emphasis Type="Italic">N</Emphasis>-ethylaniline

The preparation of N-(oxiran-2-ylmethyl)-N-ethylaniline was developed. The compound was used in the synthesis of new N-derivatives of aromatic amines containing vicinal aminoalcohol moieties.     

N‐(6‐Amino‐3‐methyl‐2,4‐dioxo‐1,2,3,4‐tetra­hydro­pyrimidin‐5‐yl)‐N‐(β‐d‐gluco­pyran­osyl)­acet­amide

The title compound, C₁₃H₂₀N₄O₈·2H₂O, i.e. (I)·2H₂O, shows no unusual features. The structure contains two mol­ecules of water of crystallization. The absolute configuration was not determined but was known from the starting materials.     

Structures and phase transitions in (K<Subscript>1-x</Subscript>Rb<Subscript>x</Subscript>)<Subscript>2</Subscript>SeO<Subscript>4</Subscript>

Summary The phase diagram of the mixed crystal (K_1-xRb_x)₂SeO₄ was determined by means of thermal analysis and neutron scattering experiments. The hexagonal to orthorhombic phase transition line exists for any x. The normal-incommensurate phase transition temperature decreases continuously with increasing Rb content. However, the incommensurate-commensurate phase transition was not observed except for K₂SeO₄. According to the clear softening of the Σ₂- Σ ₃ phonon branches and the finite frequency at 0 K for x>0.34, an existence of the hypothetical phase transition was confirmed.     

Synthesis of complex sulfide phases BaSm<Subscript>2</Subscript>S<Subscript>4</Subscript>-Tm<Subscript>2</Subscript>S<Subscript>3</Subscript> and studies of their electrolytic properties

The possibility of synthesizing complex sulfide phases in the BaSm₂S₄-Tm₂S₃ system has been studied. Tm₂S₃ solid solutions were obtained with BaSm₂S₄ (CaFe₂O₄ structural type). The samples were identified by X-ray diffraction analysis and electron microscopy. The range of the solid solutions was determined. The total conductance was studied, and the conductance activation energy was calculated for samples with different dopant contents. The electrolytic properties of basic ternary sulfide and complex sulfide phases in the BaSm₂S₄-x mol % Tm₂S₃ system were investigated. A possible mechanism of defect formation was proposed.     

Preparation of <Superscript>26</Superscript>Al, <Superscript>59</Superscript>Ni, <Superscript>44</Superscript>Ti, <Superscript>53</Superscript>Mn and <Superscript>60</Superscript>Fe from a proton irradiated copper beam dump

The station for pions cancer therapy was operated at PSI from 1980 to 1992. After a cooling time of 12 years it’s made of copper beam dump was cut and samples were taken for analytical purposes. The sampling collected about 500 g of high active copper chips that can be used for separation of exotic radionuclides. The analyses by gamma spectrometry, LSC and AMS showed main nuclides present to be ⁶⁰Co, ⁵⁴Mn, ²²Na, ⁶⁵Zn, ²⁶Al, ⁵³Mn, ⁵⁹Ni, ⁶³Ni, ⁵⁵Fe and ⁶⁰Fe and ⁴⁴Ti with a daughter nuclide ⁴⁴Sc. In the frame of ERAWAST project a procedure combining selective precipitation and ion exchange for the separation of the rare radionuclides from the copper beam dump was developed. The proposed separation procedure is easy for remote controlled implementation in a hot cell. The ion exchange separation of Ni, Al, Mg, Ti and Fe was complete and high decontamination factors for copper and cobalt were achieved. Based on the developed procedure a remotely controlled system for separation of exotic radionuclides from the copper chips was set up. The full scale system was installed in a hot cell where high activity levels can be handled. In order to evaluate the reliability and functionality of the system extensive tests have been done. During the test period 13.86 g in total of the proton irradiated copper beam dump were processed for separation of ²⁶Al, ⁵⁹Ni, ⁵³Mn, ⁴⁴Ti and ⁶⁰Fe. The results showed that the system was operational and the radionuclide separation was selective with high chemical yield. The procedure manages as well the generated liquid wastes containing high level of ⁶⁰Co activity.     

N‐Methyl‐N‐[(Z)‐2‐phenyl­propenyl]­thio­benz­amide

The crystal structure of the title thio­benz­amide, C₁₇H₁₇NS, was determined to investigate the relationship between the photoreactivity in solid state and the structure. The geometry was confirmed to be the Z isomer.