Phase formation mechanism of the Ni?+?Zr?+?polytetrafluoroethylene reactive mixture

The combustion process in the Ni?+?Zr?+?Polytetrafluoroethylene (PTFE) system is investigated. Effect of PTFE addition on the process parameters and characteristics of products are studied. The reacting mixtures and product obtained are studied by differential thermal analysis (DTA) and thermogravimetric (TG) techniques, mass-spectroscopy, ion-chromatography, and XRD analysis. Results are discussed in terms of literature data. The mechanism of combustion process is proposed according to which at initial stages monomer formed at PTFE decomposition reacts with metals to form ZrC, ZrF₂, and NiF₂. At elevated temperatures, ZrF₂ disproportionate to form gaseous ZrF₄. Heat generated at early stages of the process stimulates the formation of Ni?CZr intermetallic phases.     

Phase-Transfer catalyzed alkylation of morpholine with 1,2-dichloroethane

Russian Journal of General Chemistry -     

Effect on the magnetic properties of small substitutions of iron and copper for nickel in YNi3 and Y2Ni7 intermetallics

Measurements of magnetization in static fields up to 60 kOe and magnetic susceptibility in weak ac fields of the Y(Ni_1−x M_x)₃ and Y₂(Ni_1−x M_x)₇ intermetallics (M=Fe and Cu, x _max=0.2), as well of the specific heat of these systems for some compositions are reported. It was found that these intermetallics are ferromagnetic at low temperature, and that their spontaneous magnetizations M _s at 4.2 K and Curie temperatures T _C decrease monotonically with increasing copper concentration. The magnetic susceptibility of the Y(Ni_1−x Fe_x)₃ system with 0.06≲x≲0.2 was observed to decrease rapidly with the temperature lowered below a characteristic temperature T _s. One of possible reasons for such an anomaly is shown to be the onset in this concentration region of the reentrant spin-glass state at low temperatures. The results obtained demonstrate that the tight-binding d-band model fails to explain the evolution of the magnetic properties of YNi₃ and Y₂Ni₇ in the case of small substitutions of iron and copper for nickel. Fiz. Tverd. Tela (St. Petersburg) 39, 1828–1830 (October 1997)     

Collaboration and decision making tools for mobile groups

Nowadays the use of distributed collaboration tools is widespread in many areas of people activity. But lack of mobility and certain equipment-dependency creates difficulties and decelerates development and integration of such technologies. Also mobile technologies allow individuals to interact with each other without need of traditional office spaces and regardless of location. Hence, realization of special infrastructures on mobile platforms with help of ad-hoc wireless local networks could eliminate hardware-attachment and be useful also in terms of scientific approach. Solutions from basic internet-messengers to complex software for online collaboration equipment in large-scale workgroups are implementations of tools based on mobile infrastructures. Despite growth of mobile infrastructures, applied distributed solutions in group decisionmaking and e-collaboration are not common. In this article we propose software complex for real-time collaboration and decision-making based on mobile devices, describe its architecture and evaluate performance.     

TLC Retention Behavior of Brodifacoum,Bromadiolone, and Coumatetralyl and their Impurities on Different Adsorbents

JPC – Journal of Planar Chromatography – Modern TLC - The chromatographic behavior of three biocidal technical materials, rodenticide active ingredients brodifacoum, bromadiolone, and...     

Separating structural heterogeneities from stochastic variations in fluorescence resonance energy transfer distributions via photon distribution analysis

We establish a probability distribution analysis (PDA) method for the analysis of fluorescence resonance energy transfer (FRET) signals to determine with high precision the originating value of a shot-noise-limited signal distribution. PDA theoretical distributions are calculated explicitly including crosstalk, stochastic variations, and background and represent the minimum width that a FRET distribution must have. In this way an unambiguous distinction is made between shot-noise distributions and distributions broadened by heterogeneities. This method simultaneously and effectively extracts highly resolved information from FRET distributions. The theoretical histograms match the exact profile of histograms generated from constant transfer efficiency experimental data with a chi2 near unity. The chi2 surface suggests an ultimate level of precision with FRET of < 1% of the F?rster radius. Distributions of FRET signals in donor-acceptor-labeled DNA were unambiguously identified as being broader than shot-noise variations could explain. A model describing a Gaussian distribution of distances was tested with the PDA method and demonstrated 5 A inhomogeneities due to dye motions. The capability of this method to recover quantitative information from FRET distributions has potential applications for studying molecular conformations and dynamics. Potential sources for artifacts such as acceptor photobleaching, spectrally different observation volumes, and fluctuations of the F?rster radius are ruled out.     

Magnetic properties of nonstoichiometric Ni<Subscript>2</Subscript>MnIn Heusler alloys

Results from studies of the crystal structure, resistivity, susceptibility, and magnetization of nonstoichiometric Ni₅₀Mn_{50 − x} In _x Heusler alloys are presented. Anomalous effects discovered in temperature dependences can be interpreted as the influence of the frustrated magnetic state exhibited by manganese moments in the martensitic phase. A field-induced phase transition to the austenitic phase was observed for several concentrations around room temperature.     

Highly selective solid-state sensor for iodide based on the combined use of platinum (IV) phthalocyanine and solidified pyridinium ionic liquid

Journal of Solid State Electrochemistry - Solid-state iodide-selective electrodes based on the commercial screen-printed electrodes modified with readily available low-melting ionic material (ionic...