Piezoelectric Method for Measuring the Parameters of Shock-Induced Ejecta

This paper describes a piezoelectric method for measuring the density and mass of ejecta from the free surface of a condensed material upon arrival of a shock wave at it and the use of this method at the Institute of Physics of Explosion (Institute of Experimental Physics of the Russian Federal Nuclear Center, Sarov). Piezoelectric sensor designs and methods of recording and signal processing are presented. Results of measuring the density and mass of ejecta using piezoelectric sensors, radiography, protonography, and the method of indicator foils are compared.     

Fluorochalcogenide glasses

A new variety of chalcogenide vitreous materials—fluorochalcogenide glasses—have been synthesized by the introduction of sodium, thallium, lead, manganese, and bismuth fluorides into the Ga₂S-GeS₂ system. These glasses are characterized by high glass transition temperatures (560–670 K), an optical transmittance up to 75% in the visible (from 0.48 μm) and IR (to 7.5 μm) spectral ranges, chemical durability in reactive acid media, low crystallization ability, and the stability of physicochemical and optical properties. Depending on the introduced fluoride, the glasses can be dielectrics, semiconductors, or ionic semiconductors. The spectral investigation of fluorochalcogenide glasses by using the X-ray emission, Raman, NMR, and EPR spectroscopy reveals the complex features of their structure. The metal cations form bonds with sulfur in different structural positions. The glass network providing the mobility of sodium ions is formed in sodium fluoride-containing glasses. The formation of groupings of the [≡Ga ← F-Ge≡] type is the main structural feature of fluorochalcogenide glasses.     

Preparation of Pure Amorphous As<Subscript>2</Subscript>S<Subscript>3</Subscript> Films of a Stoichiometric Composition

The results of studying the composition of arsenic trisulphide (As₂S₃) films obtained by adding finely dispersed copper or silver powders to the starting materials for sputtering or by using triple compositions As–S–As and As–S–Cu are presented. The issues of preserving the composition of the films obtained and the degree of their purity are discussed.     

Effect of protein degradation in the axon on the speed of the bell-shaped concentration wave in slow axonal transport

This paper investigates the effect of degradation of proteins transported by means of slow axonal transport (due to enzyme-mediated breakdown of proteins) on the speed of the bell-shaped wave of protein concentration propagating toward the synapse of the axon. Another issue investigated in this paper is the effect of protein degradation on the traffic jam caused by a decay of microtubule tracks at a certain location in the axon. The decay of microtubule tracks may be caused by misregulation of microtubule-associated proteins resulting from an imbalance in intracellular signaling or by mutations of these proteins. Axonal swellings caused by such traffic jams hinder axonal transport; they are a likely cause of various neurodegenerative diseases, including Alzheimer's and Parkinson's diseases and the Down syndrome.     

An Algorithm for Cycle-Slip Detection in a Melbourne–Wübbena Combination Formed of Code and Carrier Phase GNSS Measurements

Measurement Techniques - A new algorithm has been developed for the determination and elimination of jumps in the Melbourne–Wübbena combination, formed from the code and phase...     

Chalcogenide glass containing lead halides

The glass of the As₂S₃-Sb₂S₃-PbΓ₂ system, where Γ = Cl, Br, and I, has been synthesized by welding in vacuum-treated quartz ampoules. The glass has been obtained by slow cooling in furnace. The effect of the type of halogen on vitrification has been shown; and the glass-transition temperatures have been determined.     

Boolean matrices in problems on determining the state of discrete components in computerized measurement systems

We consider theoretical application of Boolean matrices with a covering method to solve problems associated with determining the state of discrete devices during diagnostic testing. The solution is accompanied by mathematical proofs and examples. We present conditions for optimization of Boolean matrix coverings and we present an algorithm that makes it possible to obtain a minimal covering. Translated from Izmeritel'naya Tekhnika, No. 6, pp. 17–20, June, 2000.     

Special Features of Steels Alloyed with Nitrogen

The role of nitrogen as an alloying element that stabilizes austenite in steels and makes it possible to replace nickel, manganese, and other austenization promoters without deterioration of mechanical and special properties of the metal is considered. Put into practice this could reduce the volume of mining of the mentioned elements. Methods for introducing nitrogen into iron alloys are described. The mechanical properties of nitrogen-bearing steels are considered. It is shown that such steels with a structure of nitrogen martensite possess a specific strength under static and cyclic loads no worse than the strength of light structural alloys and have better fracture toughness and technological properties than the latter. The replacement of light alloys by such steels should reduce the consumption of energy in the production.     

Cyclic strength of corrosion-resistant high-nitrogen austenitic 05Kh22AG15N8MF steel during repeated tension

The static and fatigue cyclic strength of high-strength corrosion-resistant nitrogen-bearing austenitic 05Kh22AG15N8MF steel are studied in various structural states after hot rolling at 1100°C (water quenching from 1150°C, subsequent annealing at 800°C for 1 and 10 h, and cooling in air). The maximum life and a higher fatigue limit (400 MPa) are shown to be characteristic of hot-rolled samples with a finegrained austenitic structure and numerous twins. The mechanisms of fatigue crack propagation are studied.     

Approximate control optimization based on transformation of object model

It is considered an approach to approximate solving of control problems using different simplifying transformation of object model based on principles of extension or contraction of searching area and possible schemes of its realization. This approach focuses on getting, generally speaking, of a rough approximation to a global solution with two-sided estimation. Main attention focused on effective non-traditional schemes of continuous system velocity set transformation and discrete system transition set transformation. The obtained global approximate solutions can be considered as initial approximations in various iterative optimization procedures to be improved.