Research of ultrasonic sensing and mixing elements for control of magnetorheological fluids stability

Using of magnetorheological fluids (MRF) can reduce energy costs and weight and increase the devices speed and lifetime. In order to fully use all the qualities of MRF properties one must from time to time mix them and measure their properties. These systems are still being designed and tested in the laboratories. There are many structures with rheological fluid, but in many devices fluids are sealed and mechanical mixing and direct measurement of fluid properties are not possible. Effective stability control system for the rheological fluids, which supports homogeneity of the fluid, is described. (Е-mail: [email protected]

Investigation of the piezoelectric thimble tactile device operating modes

A multifunctional device to transfer graphical or text information for blind or visually impaired is presented. The prototype using tactile perception has been designed where information displayed on the screen of electronic device (mobile phone, PC) is transferred by oscillating needle, touching the fingertip. Having the aim to define optimal parameters of the fingertip excitation by needle, the computational analysis of different excitation modes has been carried out. A 3D solid computational finite element model of the skin segment, comprising four main fingertip skin layers (stratum corneum, epidermis, dermis and hypodermis) was built by using ANSYS Workbench FEA software. Harmonic analysis of its stress–strain state under excitation with different frequency (up to 10000 Hz) and harmonic force (0.01 N), acting outer stratum corneum layer in normal direction at one, two or three points has been performed. The influence of the mode of dynamic loading of skin was evaluated (in terms of the tactile signal level) on the basis of the normal and shear elastic strain in dermis, where mechanoreceptors are placed. It is shown that the tactile perception of information, delivered by three vibrating pins, may be influenced by configuration of excitation points (their number and phase of loading) and the frequency of excitation

Effect of compost on the accumulation of heavy metals in fruit of oilseed pumpkin (Cucurbita pepo L. var. styriaca)

While it is true that heavy metals accumulate in soil easily, their removal is difficult. The organic fraction of municipal solid waste can be recycled into compost, although frequent application of biowaste may lead to the accumulation of heavy metals in soil. There is no deep-rooted tradition in Lithuania to make and use various biowaste composts, including the ones produced from municipal waste. The objective of this study has been to compare the accumulation of heavy metals in different parts of oilseed pumpkin fruit depending on the chemical composition of the compost the pumpkin plants had been supplied. The content of heavy metals (HM) was determined in the soil before the plant-growing experiment, and in biowaste composts of different origin. Green waste (GW) and municipal solid waste (MSW) composts were applied to soil as fertiliser. Heavy metal concentrations in the skin, flesh and seeds of the analysed pumpkin fruits did not exceed the maximum permissible concentrations established by the EU norms. Seeds of the investigated pumpkin cultivar Olivia are more sensitive to the effect of heavy metal accumulation than the other morphological fruit parts (skin and flesh). The highest amounts of the investigated heavy metals, except Cr, were determined in the seeds, while the lowest ones, except Cu, in the flesh of oilseed pumpkin fruits. The amount of heavy metals in pumpkin biomass was not directly related to their concentrations in the soil, which proves the fact that the transfer of heavy metals from soil to plant is determined primarily by metal bioavailability and by a plant species

Estimating the selectivity of approximate string queries

Approximate queries on string data are important due to the prevalence of such data in databases and various conventions and errors in string data. We present the VSol estimator, a novel technique for estimating the selectivity of approximate string queries. The VSol estimator is based on inverse strings and makes the performance of the selectivity estimator independent of the number of strings. To get inverse strings we decompose all database strings into overlapping substrings of length q (q-grams) and then associate each q-gram with its inverse string: the IDs of all strings that contain the q-gram. We use signatures to compress inverse strings, and clustering to group similar signatures.We study our technique analytically and experimentally. The space complexity of our estimator only depends on the number of neighborhoods in the database and the desired estimation error. The time to estimate the selectivity is independent of the number of database strings and linear with respect to the length of query string. We give a detailed empirical performance evaluation of our solution for synthetic and real-world datasets. We show that VSol is effective for large skewed databases of short strings

Tubular immunostimulating complex based on cucumarioside A₂-2 and monogalactosyldiacylglycerol from marine macrophytes

<p>Abstract</p> <p>Background</p> <p>There is an urgent need to develop safe and effective adjuvants for the new generation of subunit vaccines. We developed the tubular immunostimulating complex (TI-complex) as a new nanoparticulate antigen delivery system. The morphology and composition of TI-complexes principally differ from the known vesicular immunostimulating complexes (ISCOMs). However, methodology for the preparation of TI-complexes has suffered a number of shortcomings. The aim of the present work was to obtain an antigen carrier consisting of triterpene glycosides from <it>Cucumaria japonica</it>, cholesterol, and monogalactosyldiacylglycerol from marine macrophytes with reproducible properties and high adjuvant activity.</p> <p>Results</p> <p>The cucumarioside A₂-2 - cholesterol - MGalDG ratio of 6:2:4 (by weight) was found to provide the most effective formation of TI-complexes and the minimum hemolytic activity <it>in vitro</it>. Tubules of TI-complexes have an outer diameter of about 16 nm, an inner diameter of 6 nm, and a length of 500 nm. A significant dilution by the buffer gradually destroyed the tubular nanoparticles. The TI-complex was able to increase the immunogenicity of the protein antigens from <it>Yersinia pseudotuberculosis </it>by three to four times.</p> <p>Conclusions</p> <p>We propose an optimized methodology for the preparation of homogeneous TI-complexes containing only tubular particles, which would achieve reproducible immunization results. We suggest that the elaborated TI-complexes apply as a universal delivery system for different subunit antigens within anti-infectious vaccines and enhance their economic efficacy and safety.</p

Archeological Monuments: Evidence of Strong Earthquakes in the Past (Using the Example of the Southwestern Part of the Issyk-Kul Lake Region, the Tien Shan)

This paper presents new materials and summarizes existing ones on archeoseismology studies of stony walls conducted in the Alabash-Konurolyong intramountain depression (southwestern Issyk-Kul Lake region, the northern Tien Shan). The remnants of a sublatitudinal stone wall north of the village of Kyoksay, the remnants of buildings on the Duvana pass, the "long" submeridional wall north of the village of Alabash, and ruins of the fortress of the same name located on the Alabash pass have been studied. The deformations allow us to proceed to quantitative characteristics of two seismic events that occurred in the 15th and 18th centuries. The significant PGV values (on average, 1-3 m/s) are in good agreement with results of an analysis of data on the strong ground motions and correspond to the nearest near-fault zone. These values, in accordance with the morphostructural and other paleoseismologic data, point to the vicinity (within the limits of a few kilometers) of the corresponding seismogenic fault generating them and to the development of thrust deformations of compression. Paleoseismologic data, in particular, the results of PGV value assessments, indicate the significantly larger seismic hazard of the southern shore of the Issyk-Kul Lake depression than is shown in the modern map of seismic hazards of Kyrgyzstan. We assess seismic intensity values for our investigated localities as I = 9.0 +/- 0.5. Thus, according to preliminary paleoseismology data, the seismicity level of the southern part of the Issyk-Kul Lake basin is analogous to the seismicity of its northern part. These data can be used in reevaluating the seismic hazard of the investigated territory