Tailoring 2D phononic crystal sensor properties by lattice symmerty reduction

We propose a novel method of tailoring the band structure of 2D phononic crystals (PnC) by reducing the lattice symmetry. Specifically, symmetry reduction by stretching and distorting the crystal face is explored. The transmission spectrum of the PnC was numerically calculated using the layer multiple-scattering method. Change in the shape and size of the band gaps is demonstrated as well as form of pass bands inside the stop band. The practical feasibility of the PnC sensor concept was evaluated for the case of synthetic quartz matrix and water inclusions. A distinct pattern of the pass band transformation inside the stop band which is induced by changing the distortion angle was demonstrated. The approach is in particular useful in adjusting the size and position of the gap and tailoring the size and position of the pass band in PnC sensors

Sub-wavelength phononic crystal liquid sensor

We introduce an acoustic liquid sensor based on phononic crystals consisting of steel plate with an array of holes filled with liquid. We both theoretically and experimentally demonstrate sensor properties considering the mechanism of the extraordinary acoustic transmission as underlying phenomenon. The frequency of this resonant transmission peak is shown to rely on the speed of sound of the liquid, and the resonant frequency can be used as a measure of speed of sound and related properties, like concentration of a component in the liquid mixture. The finite-difference time domain method has been applied for sensor design. Ultrasonic transmission experiments are performed. Good consistency of the resonant frequency shift has been found between theoretical results and experiments. The proposed scheme offers a platform for an acoustic liquid sensor

Control of ferroelectrics polarization for increasing of alternative energy device's efficiency coefficient

A plant, developed with the use of ferro-piezoelectric ceramics for generation of electric power, is studied in the article. The use of electrochemical generator in the plant makes it possible to increase the efficiency of electric power generation by means of polarization of ferropiezoelectric ceramics control. Polarization control is proved by a mathematical model. Consumption of 1 joule electric power, using mechanical power, generates 3,5…5 joule of electric power output. Efficiency factor of the power plant is about 50…55 percent and depends on ceramics modification and electric circuit

Single-contact pressure solution creep on calcite monocrystals

Pressure solution creep rates and interface structures have been measured by two methods on calcite single crystals. In the first kind of experiments, calcite monocrystals were indented at 40°C for six weeks using ceramic indenters under stresses in the 50-200 MPa range in a saturated solution of calcite and in a calcite-saturated aqueous solution of NH4Cl. The deformation (depth of the hole below the indenter) is measured ex-situ at the end of the experiment. In the second type of experiment, calcite monocrystals were indented by spherical glass indenters for 200 hours under stresses in the 0-100 MPa range at room temperature in a saturated aqueous solution of calcite. The displacement of the indenter was continuously recorded using a specially constructed differential dilatometer. The experiments conducted in a calcite-saturated aqueous solution of NH4Cl show an enhanced indentation rate owing to the fairly high solubility of calcite in this solution. In contrast, the experiments conducted in a calcite-saturated aqueous solution show moderate indentation rate and the dry control experiments did not show any measurable deformation. The rate of calcite indentation is found to be inversely proportional to the indenter diameter, thus indicating that the process is diffusion-controlled. The microcracks in the dissolution region under the indenter dramatically enhance the rate of calcite indentation by a significant reduction of the distance of solute transport in the trapped fluid phase. This result indicates that care should be taken in extrapolating the kinetic data of pressure solution creep from one mineral to another

Experimental pressure solution compaction of synthetic halite/calcite aggregates.

Experimental observations are reported of weakening of sediment-like aggregates by addition of hard particles. Sieved mixtures of calcite and halite grains are experimentally compacted in drained pressure cells in the presence of a saturated aqueous solution. The individual halite grains deform easily by pressure solution creep whereas calcite grains act as hard objects and resist compaction. The fastest rate of compaction of the mixed aggregate is not obtained for a 100% halite aggregate but for a content of halite grains between 45% and 75%. We propose that this unusual compaction behavior reflects the competition between two mechanisms at the grain scale: intergranular pressure solution at grain contacts and grain boundary healing between halite grains that prevent further compaction

Clinical and morphological features of head and neck melanomas in comparison with other localizations in Kursk region population

The analysis of clinical and morphological data on 521 hospitals verified by histologically melanoma of the skin of different locations located in different clinics of Kursk from 2013 to 2017 in order to identify the clinical and morphological features of melanoma of the head and neck in comparison with other localizations. Statistically significant features of clinical and morphological data of head and neck melanoma were revealed.Проведен анализ клинико-морфологических данных о 521 больном верифицированной гистологически меланомой кожи различных локализаций, находившихся на лечении в различных клиниках г. Курска с 2013 по 2017 год с целью выявления клинико-морфологических особенностей меланом головы и шеи в сравнении с другими локализациями. Выявлены статистически значимые особенности клинико-морфологических данных меланом головы и шеи

The technology of increasing the energy density of batteries by controlling the degree of polarization of ferroelectrics

The paper deals with a power plant developed with the use of ferro-piezoelectric ceramics to increase the energy density of electric vehicle batteries. Electrochemical generator in the plant makes it possible to significantly increase electrical energy by means of controlling the degree of polarization of ferro-piezoelectric ceramics. Application of the plant in an electric vehicle increases the range on a single charge by 3.5…5 times. Efficiency factor of the power plant is about 50...55% and depends on ceramics modification and electric circuit