scholarly journals Termite pyrotechnic compositions of iron and alkaline earth metals peroxides

2020 ◽  
pp. 55-72
Author(s):  
Andrzej Wojewódka ◽  
Marcin Gerlich
Keyword(s):  
Time Delay ◽  
Solid State ◽  
Alkaline Earth ◽  
Front Propagation ◽  
Xrd Analysis ◽  
Propagation Rate ◽  
Alkaline Earth Metals ◽  
Pyrotechnic Compositions ◽  
Iron Based ◽  
Delay Elements

The fallowing article presents the combustion studies of Fe/alkaline earth metals peroxides composition. It contains a literature review and the results of own research, which aim is to determine the possibility of using iron-based thermite compositions in time delay elements. The article focuses on the investigation of combustion front propagation rate as a function of a pressing load, the iron content and the purity of used oxidants. The DSC, TG and XRD analysis confirmed that reactions in this system occurs mainly in the solid state.

Niobium-bearing arsenides and germanides from elemental mixtures not involving niobium: a new twist to an old problem in solid-state synthesis

2018 ◽  
Vol 74 (5) ◽  
pp. 623-627 ◽  
Author(s):  
Sviatoslav Baranets ◽  
Hua He ◽  
Svilen Bobev
Keyword(s):  
High Temperature ◽  
Solid State ◽  
Diffraction Data ◽  
Alkaline Earth ◽  
Alkaline Earth Metals ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Temperature Reactions ◽  
First Time ◽  
Synthetic Work

Three isostructural transition-metal arsenides and germanides, namely niobium nickel arsenide, Nb0.92(1)NiAs, niobium cobalt arsenide, NbCoAs, and niobium nickel germanide, NbNiGe, were obtained as inadvertent side products of high-temperature reactions in sealed niobium containers. In addition to reporting for the very first time the structures of the title compounds, refined from single-crystal X-ray diffraction data, this article also serves as a reminder that niobium containers may not be suitable for the synthesis of ternary arsenides and germanides by traditional high-temperature reactions. Synthetic work involving alkali or alkaline-earth metals, transition or early post-transition metals, and elements from groups 14 or 15 under such conditions may yield Nb-containing products, which at times could be the major products of such reactions.

scholarly journals Solid State Hydrogen Storage in Alanates and Alanate-Based Compounds: A Review

Metals ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 567 ◽  
Author(s):  
Chiara Milanese ◽  
Sebastiano Garroni ◽  
Fabiana Gennari ◽  
Amedeo Marini ◽  
Thomas Klassen ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Hydrogen Absorption ◽  
Alkaline Earth ◽  
Molecular Form ◽  
Alkaline Earth Metals ◽  
Highly Porous Materials ◽  
Physico Chemical ◽  
Solid Form ◽  
Highly Porous

The safest way to store hydrogen is in solid form, physically entrapped in molecular form in highly porous materials, or chemically bound in atomic form in hydrides. Among the different families of these compounds, alkaline and alkaline earth metals alumino-hydrides (alanates) have been regarded as promising storing media and have been extensively studied since 1997, when Bogdanovic and Schwickardi reported that Ti-doped sodium alanate could be reversibly dehydrogenated under moderate conditions. In this review, the preparative methods; the crystal structure; the physico-chemical and hydrogen absorption-desorption properties of the alanates of Li, Na, K, Ca, Mg, Y, Eu, and Sr; and of some of the most interesting multi-cation alanates will be summarized and discussed. The most promising alanate-based reactive hydride composite (RHC) systems developed in the last few years will also be described and commented on concerning their hydrogen absorption and desorption performance.

scholarly journals Compartmentalization of Alkaline-Earth Metals in Salen-Type Cu- and Ni-Complexes in Solution and in the Solid State

ACS Omega ◽  
2019 ◽  
Vol 4 (6) ◽  
pp. 10231-10242 ◽  
Author(s):  
Alba Finelli ◽  
Nelly Hérault ◽  
Aurélien Crochet ◽  
Katharina M. Fromm
Keyword(s):  
Solid State ◽  
Alkaline Earth ◽  
Alkaline Earth Metals

The Effects of Alkaline Earth Metals on the Structure of Sodium Borosilicate Glasses: 11B and 29Si NMR Study

2020 ◽  
Vol 989 ◽  
pp. 192-198
Author(s):  
Viacheslav Eremyashev ◽  
Leyla M. Osipova ◽  
Ilya Shenderovich
Keyword(s):  
Solid State ◽  
Nmr Spectroscopy ◽  
Nmr Spectra ◽  
Alkaline Earth ◽  
Alkaline Earth Metals ◽  
Borosilicate Glasses ◽  
Polymerization Degree ◽  
Structural Units ◽  
Nmr Study ◽  
Alkali Borosilicate Glasses

The effect of substitution of alkaline earth metals for sodium on the structure of alkali borosilicate glasses had been studied using the solid-state 11B and 29Si NMR spectroscopy. NMR spectra enable to evaluate the relative mole fractions of different silicon and boron structural units in studied samples. The obtained results demonstrate that alkaline earth metals increase the polymerization degree of the silicon structural units at the expense of de-polymerization of the boron units. The reason for these changes is preferential coordination of sodium and alkaline earth metals to the boron units, that increases strongly for the studied alkaline earth metals.

scholarly journals OXIDATION KINETICS OF ALUMINUM ALLOY AK12M2, MODIFIED BY BARIUM, IN SOLID STATE

2020 ◽  
Vol 55 ◽  
pp. 28-33
Author(s):  
Izatuiio. N. Ganiev ◽  
◽  
Furkatshokh Sh. Zokirov ◽  
Murodali M. Sangov ◽  
Asadkul E. Berdiyev ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Solid State ◽  
Oxidation Kinetics ◽  
Alkaline Earth ◽  
Oxidation Process ◽  
Dominant Role ◽  
Alkaline Earth Metals ◽  
Protective Properties ◽  
Initial Alloy ◽  
Kinetics Of

The oxidation kinetics of the AK12M2 aluminum alloy modified to 1.0% by barium was studied using thermogravimetry method. It was shown that the addition of barium to the alloy and the increase in temperature increase the oxidation rate of the initial alloy in the solid state. The apparent activation energy of the oxidation process of the AK12M2 aluminum alloy is 127.73 kJ/mol and decreases to 71.85 kJ∕mol for the alloy with 1.0% barium. The oxidation curves of the AK12M2 aluminum alloy with barium in the solid state are described by polynomials indicating the hyperbolic mechanism of that process. The mechanism of influence of barium on the oxidability of the AK12M2 aluminum alloy was established. It lies in the fact that barium in the range of 0.3-1.0% plays a dominant role in the formation of an oxide film, which is characterized by low protective properties. Barium influence is explained by its physicochemical properties as one of the alkaline earth metals.

scholarly journals Synthesis and properties of halogen-containing macrocyclic anthraquinone imines – chemosensors for metal cations

2020 ◽  
Vol 16 (2) ◽  
pp. 50-56
Author(s):  
Alexandra A. Kudrevatykh ◽  
Lyubov S. Klimenko
Keyword(s):  
Solid State ◽  
Alkaline Earth ◽  
Spectral Response ◽  
Aqueous Media ◽  
Earth Metal ◽  
Metal Cations ◽  
Alkaline Earth Metals ◽  
Alkaline Earth Metal ◽  
Test Systems ◽  
First Time

New crown-containing imines of 1-hydroxyanthraquinone with chlorine and fluorine atoms in the anthraquinone nucleus were synthesized. For the first time, the thermal and photochemical stages of synthesis are carried out in the solid state (without a solvent). The features of complexation of new chemosensors with cations of alkaline and alkaline earth metals were studied by spectrophotometry. It is shown that the introduction of halogen atoms in the anthraquinone nucleus leads to a significant spectral response. The obtained compounds are tested as components of test systems for visual determining the presence of alkaline earth metal cations in aqueous media.

scholarly journals Azide Method for Generating Metal Vapors in Space

2020 ◽  
pp. 102-108
Author(s):  
Anatoly I. Drobyzhev ◽  
Alexander M. Pyzhov ◽  
Dmitry A. Sinitsyn
Keyword(s):  
Alkaline Earth ◽  
High Efficiency ◽  
Metal Vapor ◽  
Alkaline Earth Metals ◽  
Earth Space ◽  
Near Earth Space ◽  
Metal Vapors ◽  
Pyrotechnic Compositions ◽  
Azide Method

Modern methods of rocket research of the upper layers of the atmosphere and near-Earth space cannot be imagined without the use of glowing artificial clouds (GAC). Traditional pyrotechnic methods for generating vapors of alkali and alkaline earth metals, used for the formation of GAC in space, are ineffective and require, as a rule, the use of metals with high chemical activity. The article presents the results of studies on the development of an alternative method for generating vapors of alkali and alkaline earth metals to create GAC in near-Earth space using inorganic azides of the corresponding metals. The long-term use of pyrotechnic metal vapor generators to create GAC in the upper atmosphere, equipped with azide pyrotechnic compositions, confirmed their high efficiency, reliability and safety of use.

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