An alternative method of estimating uncertainty

A method of estimating the uncertainty of the result of a measurement is proposed, which is more universal, simple, and accurate than the law of the spread of uncertainty. The method is based on the traditional experimental approach to estimating the variance, on the introduction of the idea of introduced uncertainty and a proof of its close connection with the precision of the measurements. __________ Translated from Izmeritel’naya Tekhnika, No. 5, pp. 15–18, May, 2007.     

Displacement of igniter and specimen materials in combustion of gas-free systems in a rigid shell

We present results from an investigation into the burning of a gas-free Ti + C system (diluted to 20% with titanium carbide), this system contained in combination with an igniter tablet fabricated out of a Cr₂O₃ + 2Al + 4B mixture in a rigid shell. We have demonstrated that the burning is accompanied by displacement of the material through the appearance of a decompression wave (a sharp reduction in density in the vicinity of the combustion front), thus leading to a change in the burning velocity.Moscow. Translated from Fizika Goreniya i Vzryva, No. 2, pp. 94–97, March–April, 1991.     

Diamond films: Initial CVD growth stage using nanodiamonds as nucleation centers

Scanning electron microscopy is used to study features of a mechanism operating in the initial growth stages during the CVD of diamond films on nucleation centers representing predeposited nanodiamonds obtained by method of detonation synthesis.     

Strength and Fracture of SPKh18N9T Steel and SP36KNM Alloy under Dynamic Loading

We present results of an experimental investigation of the strength properties of SPKh18N9T steel and SP36KNM alloy and the characteristics of fracture processes in these materials under dynamic loading. It is shown that, under conditions of uniaxial static tension, the standard mechanical characteristics of these materials are very close to each other. Moreover, as the strain rate increases to 10³ sec^?1, they undergo slight changes (thus, the yield limit and the ultimate strength increase by at most 13% and 6%, respectively, and the relative elongation at rupture decreases by 5%). At the same time, under impact loading, the impact strength of SPKh18N9T steel is twice that exhibited by SP36KNM alloy. This fact can be partially explained by the difference in the initial porosities of these materials.     

Effect of Feedstock and Gas Atmosphere Composition on Selectivity and Distribution of Hydrocarbon Groups in Gasoline Synthesis from Oxygenates

Gasoline has been synthesized from oxygenates (dimethyl ether and methanol) on a HZSM-5 zeolite catalyst, modified by palladium and zinc, in a micropilot unit operating in the continuous recycle flow mode. The influence of the gas atmosphere composition—synthesis gas, hydrogen, and methane—on the gasoline selectivity, and on-stream stability of the catalyst has been determined for dimethyl ether (DME) used as a feedstock. The hydrocarbon composition and the carbon distribution in the products have been compared using DME and methanol as the feedstock in the synthesis-gas atmosphere. It has been shown that the higher gasoline selectivity production in the case of methanol is due to the higher concentration of aromatic hydrocarbons, which is achieved by decreasing the intensity of their dealkylation.     

Planar microcavity containing luminescent diamond particles with embedded silicon-vacancy color centers in its active layer

A planar hybrid microcavity containing isolated diamond particles with embedded silicon-vacancy (Si-V) color centers in its active layer is fabricated by plasma-enhanced chemical vapor deposition. Distributed Bragg reflectors are produced on the basis of alternating quarter-wave a-Si_{1 ? x} C _x :H and a-SiO₂ layers. The color centers are controllably introduced from the gas phase during the course of growth of the diamond particles. A narrowing to 5 nm of the zero-phonon line at a wavelength of 738 nm and suppression of the phonon wing in the photoluminescence spectrum of the Si-V color centers are achieved.     

Chemical vapor deposition of isolated spherical diamond particles with embedded silicon-vacancy color centers onto the surface of synthetic opal

Isolated spherical diamond particles with embedded silicon-vacancy color centers are synthesized on a patterned surface of synthetic opal by chemical vapor deposition methods. The phase composition of the particles is determined and their structural and luminescence properties are studied. Prospects are discussed for the application of these particles as integrated spherical diamond microcavities, in which color centers are situated directly in the microcavities.     

ISO 5725 standard and reference laboratories: Error requirements

Criteria for estimating the systematic and random errors of reference laboratories are proposed on the basis of the approaches presented in the ISO 5725 standard. __________ Translated from Izmeritel’naya Tekhnika, No. 2, pp. 27–30, February, 2006.     

Uncertainty of Measurements. Part 1

Proofs are given of the coincidence of the concepts of precision and uncertainty and also of the absence of a problem in choosing between the corresponding concepts of measurement accuracy. It is shown that an estimate of the quality of measurements using the approach of the Guide to the Expression of Uncertainty in Measurement is inferior in accuracy and universality to an estimate using the approach and procedure of the State standard GOST R ISO 5725.     

A pulsed liquid ionization chamber filled with Xe,Ar and CH4

A pulsed liquid ionization chamber filled with Xe, Ar and CH₄ is described and its characteristics are presented. The energy resolution for the detection of γ-quanta with an energy of 1836 keV amount to 4.9%, 4.1% and 6.2% for the xenon, argon and methane fillings, respectively. Dependences of the yields of free electrons from the electron tracks in the liquids (Xe, Ar, CH₄) on the electric field strength and the electron energy are obtained.