Comparative study of the behavior of ammonium phosphate in fireproofing intumescent formulations

A comparative study of the behavior of ammonium dihydrogen phosphate and partially substituted ammonium polyphosphates in fireproofing formulations based on organic solutions of polymers was made. Differences in the interaction of monomeric and polymeric acidic salts with the surface of a metal being protected were revealed.     

Elastic properties of the Ta–V system: bcc Ta0.33V0.67 and C15 TaV2

Resonant ultrasound spectroscopy was used to measure the elastic constants of bcc Ta_0.33V_0.67 over the temperature range 3.5–300?K; the results were compared to earlier measurements on C15 TaV₂. The temperature dependence of the polycrystalline shear modulus is completely different in the two phases; that of the bcc phase decreases with temperature whereas that of the C15 phases increases in an anomalous fashion. This difference is consistent with a model involving doubly-degenerate levels at the X point of the Brillouin zone in the C15 phase with the Fermi level lying near the doubly degenerate level. This model accounted for the unusual behaviour of the C15 phase. Debye temperatures were determined from the ultrasonic measurements: 295?K for the C15 phase and 315?K for the bcc phase.     

Early diagnosis of lung cancer based on proteome analysis of exhaled breath condensate

A comparative study of the exhaled-breath-condensate (EBC) proteome that was obtained for four donor groups was carried out using ion cyclotron resonance mass spectrometry with electrospray ionization. The groups included subjects with diagnosed lung cancer, chronic obstructive pulmonary disease, community-acquired pneumonia, and healthy nonsmoking control subjects. More than 300 proteins were identified, while 19 of them were found in the EBC samples of the donors who were diagnosed with lung cancer in the early stages and are potentially significant in the development of a diagnostic lung-cancer biomarker panel. It was shown that the EBC protein profiles of different donor groups can be distinguished. It may be possible to highlight a specific protein group that is typical for certain conditions/diseases of the respiratory system. Thus, the EBC analysis could be a promising non-invasive method for early diagnosis of lung cancer.     

Test facility for nuclear planetology instruments

An experimental facility for testing and calibrating nuclear planetology instruments has been constructed in partnership between the Space Research Institute (Moscow) and the Joint Institute for Nuclear Research. A model of Martian soil with a size of 3.82 × 3.21 m² and an overall mass of about 30 t is assembled from silicate glass. Glass is chosen in order to imitate absolutely dry soil close in composition to the Martian one. The heterogeneous model allows one to imitate the average elemental composition of Martian soil in the best possible way by adding layers of the necessary materials to it. Near-surface water ice is simulated by polyethylene layers buried at different depths within the glass model. A portable neutron generator is used as the neutron source for testing active neutron and gamma spectrometers. The facility is radiation-hazardous and is thus equipped with interlock and radiation monitoring systems in accordance with the effective regulations.     

Observation of truly cold fragmentation of a heavy nucleus

The results of a careful investigation of the mass-energy-charge correlations of the fragments produced by fission of thorium-232 by 5 MeV neutrons are presented. The phenomenon of truly cold fragmentation of a thorium nucleus into tellurium-134 and strontium-99 in the quantum ground states is observed. It is shown that the reaction energy is completely exhausted by the kinetic energy of the fragments in their mutual field. Pis’ma Zh. éksp. Teor. Fiz. 67, No. 10, 752–754 (25 May 1998)     

New indications of collinear tripartition in 252Cf(sf) studied at the modified FOBOS setup

An attempt has been made to search for collinear tripartition in spontaneous fission of ²⁵²Cf by using the FOBOS setup coupled with the neutron detector belt. A group of rare events were detected characterized by reduced total kinetic energy and total nuclear charge gated by the large neutron multiplicity measured. This fact is considered to be an experimental indication of collinear tripartition in ²⁵²Cf. The theoretical indication of the possible existence of the collinear cluster tripartition valley was obtained for the first time.     

Scattering of very cold neutrons from the supramolecular structure of ethylene copolymers with substituted norbornene, 5-ethylidene-2-norbornene

The transformation of the nanostructure of ethylene copolymers with 5-ethylidene-2-nonbornene due to variations in the concentration of 5-ethylidene-2-nonbornene is studied using scattering of very cold neutrons. The cyclic monomer is introduced into the polyethylene chain in order to modify the supramolecular structure of polyethylene and to change its macroscopic properties. It is shown that, as the content of 5-ethylidene-2-nonbornene in the copolymer increases, the amorphous-crystalline structure of polyethylene is destroyed (the crystallinity and average crystallite size decrease). Neither scattering of very cold neutrons nor X-ray diffraction are observed in samples of ethylene copolymers in which the content of 5-ethylidene-2-nonbornene exceeds 35 mol %. The transmission of light in copolymers of ethylene with 5-ethylidene-2-nonbornene is measured at different wavelengths. It is found that an increase in the content of 5-ethylidene-2-nonbornene in the copolymer leads to an increase in the transparency of the material.     

Splitting of magnetic dipole modes in anisotropic TiO2 micro‐spheres

Monocrystalline titanium dioxide (TiO₂) micro‐spheres support two orthogonal magnetic dipole modes at terahertz (THz) frequencies due to strong dielectric anisotropy. For the first time, we experimentally detected the splitting of the first Mie mode in spheres of radii m through near‐field time‐domain THz spectroscopy. By fitting the Fano lineshape model to the experimentally obtained spectra of the electric field detected by the sub‐wavelength aperture probe, we found that the magnetic dipole resonances in TiO₂ spheres have narrow linewidths of only tens of gigahertz. Anisotropic TiO₂ micro‐resonators can be used to enhance the interplay of magnetic and electric dipole resonances in the emerging THz all‐dielectric metamaterial technology.