Search results for "lcsh:T"
showing 10 items of 2832 documents
Evidencias de un recubrimiento de magnetita artificial en el armamento íbero
2011
A metallographic study of two pre-roman Iberian arms, affected by a cremation process, revealed the presence of an outer magnetite layer, providing highly protective properties. This layer is extraordinarily tenacious and of very homogeneous thickness, indicating an intentional manufacturing process rather than an accidental formation during the severe heating/cooling cycles the artefact suffered. Up to date, the intentional production of these types of layers has been attributed to a welding process of three different metallic sheets, here an alternative model is proposed, allowing, as could be simulated in the laboratory, the virtually exclusive formation of a magnetite coating.<br>…
A Study of Mechanical Properties of Polymer Composite Membranes with Various Ionic Liquids at Elevated Temperatures
2019
This work was supported by Latvian Council of Science (Cooperation project No.666/2014.4).
Modification of the Structure and Nano-Mechanical Properties of LiF Crystals Under Irradiation with Swift Heavy Ions
2011
The modifications of the structure and hardness of LiF crystals under high-fluence irradiation with MeV- and GeV-energy Au ions have been studied using nanoindentation and atomic force microscopy. The formation of ion-induced dislocations and bulk nanostructures consisting of grains with nanoscale dimensions (50 nm - 100 nm) has been observed. The structural modifications are accompanied by a strong ion-induced hardening which is related to dislocation impeding by assemblies of defect aggregates, dislocation loops of vacancy and interstitial types and grain boundaries. For MeV ions, the modifications are localized in a thin surface layer (few mm) where much higher density of deposited energ…
Green approach to corrosion inhibition of stainless steel in phosphoric acid of Artemesia herba albamedium using plant extract
2019
Essential oil from aerial parts of Artemisia herba-alba from Morocco was hydrodistilled and its chemical composition oil was investigated by capillary GC and GC/MS. The major components were 1,8-cineole (35.6%) and camphor (24.1%). Artemisia herba-alba essential oil AHAO was tested as corrosion inhibitor of stainless steel (SS) in 1M H3PO4 using potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy measurements (EIS) and scanning electronically microscopy (SEM) studies. The results obtained showed that the essential oil of Artemisia reduces the corrosion rate. Tafel polarization method indicates that the plant extract behaves as a mixed type inhibitor. The inhibition…
Growth of beryllium oxide nano-structures during thermal treatment of neutron irradiated beryllium
2015
Beryllium oxide nano-structures grown during high temperature oxidation of neutron irradiated beryllium has been investigated. Oxidation of non - irradiated and neutron irradiated beryllium was performed in differential thermal analyzer in an atmosphere of air and its mixture with helium at temperatures up to 1050°C. Structure of beryllium and its oxide was studied by the means of scanning electron microscopy. The growth of beryllium oxide nano-structures – “labyrinth type” layers and nano-rods on the inner surfaces of neutron irradiated beryllium were observed by means of Scanning Electron Microscopy. The size of the rods was 10-100 nm in diameter and up to few micrometers in length. There…
Development of Composites with a Self-Healing Function
2015
This research aimed to realize experimentally the facilevascular self-healing system in epoxy glass fibre reinforced composite. Using flexiblepolytetrafluoroethylene tubes as removable preforms, the channels were embeddedinto both neat epoxy resin and unidirectional glass-fibre reinforced epoxy laminate.Room temperature curable epoxy resin with a surfactant and an amine-basedhardener were the components of the binary healing agent. The specimens oftapered double cantilever beam geometry were subjected to Mode I fracture tests.Fracture of specimens released the healing agent from channels and triggeredself-healing process of the crack. Tested neat epoxy resin specimensdemonstrated recovery o…
Modified Graphene Sheet Stacks for Hydrogen Binding
2017
Results are partially obtained using infrastructure of Lithuanian Energy Institute with support of COST Action MP1103 “Nanostructured materials for solid-state hydrogen storage”. Latvian National Research program IMIS2 is greatly acknowledged for financial support
Rayleigh Equation Anomaloscope from Commercially Available LEDs
2012
Most precise classification of CVD (color vision deficits) can be provided by using anomaloscope. Today anomaloscopes are available, which can evaluate red-green (Rayleigh) and blue-green (Moreland) color defects.DOI: http://dx.doi.org/10.5755/j01.ms.18.2.1928
The Synthesis, Characterization and Sintering of Nickel and Cobalt Ferrite Nanopowders
2012
The NiFe2O4 and CoFe2O4 ferrites were synthesized by two methods – chemical sol-gel self-combustion method and the high frequency plasma chemical synthesis and magnetic properties, crystallite size, specific surface area of synthesized products are characterized. Nanopowders synthesized in the high frequency plasma are with specific surface area in the range of (28 – 30) m2/g (the average particle size (38 – 40) nm, crystallite size ~40 nm). The ferrite nanopowders obtained by sol-gel self-combustion method have the specific surface area of (37 – 43) m2/g (average particle size (26 – 31) nm, crystallite size (10 – 20) nm). All synthesized nanopowders were sintered via pressure-less sinterin…
Softening of Silica Filled Styrene-Butadiene Rubber under Uniaxial Cyclic Loading
2016
Stress-strain behaviour of silica filled styrene-butadiene rubber showed strong hysteresis and cyclic softening, while these effects were almost negligible for the neat rubber. Significant Mullins effect occurs between the first and second loading cycles, whereupon samples reach their steady state after four repeated cycles. The degree of softening increases with volume content of silica characterizing the softening effect as a breakdown of the filler-formed microstructure defined by both, specific interactions in the filler associations and between the filler and rubber matrix. Contribution of different damage mechanisms to the total energy losses on different stages of extension was estim…