Thermoheliox: effect on the functional hemodynamics of the human brain

A kinetic study of the effect of thermoheliox (inhalation of a helium and oxygen mixture, 70 °C) on the functional hemodynamics of the human brain by functional magnetic resonance imaging was carried out. The dynamic responses of the BOLD signal were found to be biphasic. An empirical equation describing the first phase of the hemodynamic response to visual stimulus was proposed. It was shown that preliminary inhalation of thermoheliox stimulates the hemodynamic responses by slowing down the vasoconstriction.

     

A method for calculating the enthalpy of hydrophobic effect

A new method for calculating the enthalpy of hydrophobic effect for compounds incapable of specific interactions with water was suggested. The method is based on separating the enthalpy of hydration into the contributions from nonspecific hydration and hydrophobic effect. The contribution from nonspecific hydration was determined by a method described previously. The enthalpies of hydrophobic effect for inert gases, alkanes, aromatic hydrocarbons, and their derivatives were determined. It was found that the enthalpy of hydrophobic effect for inert gases and alkanes is negative and independent of the size of the molecule dissolved in water. For aromatic compounds, the enthalpy is positive; it increases with the molecular size.     

Röntgenographische Hochtemperaturuntersuchung der Thermischen Zersetzung von Dodekawolframatoborsäure

Investigation on the Thermal Degradation of 12-Tungstoboric Acid by Means of X-ray Heating Photographs By means of X-ray Guinier investigation of 12-tungstoboric acid hexahydrate H₅[BO₄W₁₂O₁₂] · 6H₂O at room temperature a monoclinic lattice was determined, being in disagreement with the literature. The LSQ-refinement of parameters of the monoclinic C-lattice give a = 1.728 nm, b = 1.215 nm, c = 1.216 nm, b? = 135° 34′, Z = 2, d_exp. = 5.44 g cm^?3, d_calcd. = 5.52 g cm ^?3. From X-ray heating patterns (heating rate: 4°C/min, atmosphere: air) the formation of a new monoclinic phase at 185°C was found, being stable till 270°C. From 270–420°C exist a bad crystalline phase and from 420–840°C a monoclinic phase: a = 0.532 nm, b = 0.389 nm, c = 0.522 nm, b? = 91° 09′. Above 840°C a tetragonal phase is formed with a diagram typical for pure WO₃. The relationship between the modifications is discussed.     

Kinetics of inactivation and effects of stabilization of chloroplasts

The kinetics of inactivation of the electron transport chain of isolated chloroplasts was investigated. Methods for the stabilization of chloroplasts were developed. The mean operating time of the system was increased by a factor of about 200.     

Metastable ionic cubic structure I clathrate hydrate formed with tetra-n-butylammonium bromide

1. Download : Download high-res image (143KB)
2. Download : Download full-size image

     

Synthesis of 5,10,15,20-tetra[6' -nitro-1,3,3-trimethylspiro- (indolino-2,2' -2H-chromen-5-yl)]porphyrin and its metal complexes

A new 5,10,15,20-tetrasubstituted porphyrin containing four 6’-nitro-1,3,3-trimethylspiro(indolino-2,2’-2H-chromene) substituents and its complexes with Zn²⁺ and Cu²⁺ ions were prepared and characterized by physicochemical methods of analysis.     

Macrokinetics of carbonaceous feedstock pyrolysis in a tubular reactor of variable cross section

A macrokinetic model of carbonaceous feedstock pyrolysis in a tubular reactor of variable cross section was constructed. It was shown that, to intensify the pyrolysis in such a tubular reactor, its diameter should vary depending on the viscosity of the reaction products.     

Analysis and monitoring of the stressed state in solids by gas sensors

Gas release from solids under mechanical stressing of specimens up to failure was studied. The amount of hydrogen being released vs. strain developed in a specimen under step-by-step loading was measured. The hydrogen evolved in strained metals (iron, nickel, copper, aluminum, etc.) and some epoxy-resin-based composites was detected by chemical sensors in a gas atmosphere at normal atmospheric pressure. The amount of hydrogen was shown to grow with the amount of plastic strain and peak upon failure. A method for strain analysis in solids was worked out. It was applied to analyze the stressed state of the rotor material of a centrifuge during its operation.