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Since the beginning of the twentieth century, abstract art has formed a central stream of modern art. To attain purely aesthetic goals, many avant-garde artists turned painting in particular into a pursuit of breaking off the relations with natural forms. Instead of copying them, they have merely relied on their inner visions. When externalizing these visions directly on the canvas or sheets of paper, the practitioners of abstract art have inadvertently used the phenomenological method and its epoché. In this essay I argue that the philosophies of Kupka and Husserl are largely compatible. This is not because the two use the same terminology, but because they virtually mean and do the same thing in their respective fields. Even where there are significant differences between them, these are not as great as it might at first seem. In the essay’s conclusion I sum up some of the most significant implications their compatible theories have for the philosophy of art and for various theories of art today.

While examining the airflow generated between the asymmetrical electrodes connected to high voltage, the authors investigated the possible limitations of the particle image velocimetry (PIV) method in the presence of strong electric fields. The tracer particles used in the PIV method in these conditions are affected by electromagnetic forces, therefore, it is necessary to determine whether these forces have any non-negligible negative influence on the measurement results. For this purpose, the authors theoretically analyzed all the possible forces and measured the generated airflow using PIV and constant temperature anemometry methods. The experimental and theoretical results clearly show the viability of the PIV measurement method even in these very specific conditions.

The electric properties of polymers are increasingly important in a wide range of applications such as sensors, energy storages, microelectronics, and filtration membranes among others. In this work, the effect of multi-energetic Au ion implantation on the graphene oxide (GO), polyimide (PI), polyethylene terephthalate (PET) and polylactide (PLLA) elemental, chemical, structural end electric properties is presented with potential application in 3D metal-dielectric structure synthetization. The three energies, 3.2, 1.6, 0.8 MeV of Au ions with fluence 3.75×1014 cm-2 were used in ascending or descending order to create two sample sets, which were subsequently analysed by RBS, ERDA, EDS and AFM. RBS analysis was used for Au-depth profile characterization in the implanted samples, the profiles agree reasonably with those simulated by SRIM code. Electrical properties were investigated by standard two-point technique with respect to the used parameters of the ion irradiation. The sheet resistance decreases after ion irradiation and it is evident that the ascending order of ion implantation energies has more significant effect on the conductivity enhancement compare to the descending one.

NanospiderTMmethod allows preparation of nanofiber sheets with desired specific mass and fiber diameter between 100-600 nm. The fiber diameter can be modified by solvent system, concentration of polymer solution, and external conditions of the electrospinning process, in particular by air humidity and temperature. We have long experience with continual electrospinning from free surface of the polymer solution and in this case we focus on polymer blend polyamide 6/chitosan nanofiber form. Chitosan is an excellent material providing biocompatibility and numerous primary amine groups. On the other hand, polyamide 6 is well known and easy-to-prepare stable polymer guaranteeing sufficient mechanical properties. Blend nanofibers containing synthetic and natural polymers are usually difficult to continuously prepare. Natural polymer bring certain inhomogeneity due to varying chemical and physical properties of each brew. We compared chitosan from four different suppliers and finally fabricated homogenous and long-term stable layers. Successfully prepared nanofiber sheets were used as a support for enzyme immobilization. We showed that our layers can be used as a carrier for numerous biomolecules.

The nuclear disposal concept is based on compacted bentonite barrier placed into a borehole in the host rock. In crystalline rock, one of the issues is a non-uniform saturation of bentonite caused by inhomogeneity of the rock, typically the flow being concentrated to fractures. We solve a hydro-mechanical model problem in bentonite in the general engineering multiphysics simulation software ANSYS. The elasto-plastic transition as result of saturation is represented by a special non-linear stress-strain curve of elastic model (saturation-dependent weakening). The model is further extended to a contact-problem formulation, where the swelling is possible either as free swelling until filling the gap or as confined state after. It is a synthetic case of one horizontal fracture crossing a vertical borehole. We demonstrated that for large time period, the saturation is limited to a part of the volume, producing a non-uniform stress field in the whole volume. The stress is also controlled by the gap width.

Lynn Gamwell’s book traces the quasi-simultaneous origin of mathematics and art featuring a cultural history, from prehistory to the present. The publication boldly asserts that mathematical branch...

This article discusses the problem of spatial mapping for our test UGV using the Kinect device and the UNITY 3D game engine. It describes in detail how to obtain and process spatial data from Kinect with their transmission and transformation at the game engine level. There is also presented an aspect of accuracy and possible pitfalls using Kinect for spatial mapping.

The performance of concrete structures in fire depends on several factors which include, among others, the change in material properties due to the fire. Today, fiber reinforced concrete (FRC) belongs to materials which have been widely used for various structures and elements. While the knowledge and experience with FRC behavior under ambient temperature is well-known, the effect of elevated temperature on its behavior has to be deeply investigated. This paper deals with an experimental investigation and stress‑strain relations for hybrid fiber reinforced concrete (HFRC) which contains siliceous aggregates, polypropylene and steel fibers. The main objective of the experimental investigation is to enhance a database of mechanical properties of concrete composites with addition of fibers subject to elevated temperature as well as to validate existing stress-strain relations for HFRC. Within the investigation, a unique heat transport test, compressive test and splitting tensile test were performed on 150 mm cubes heated up to 200, 400, and 600 °C with the aim to determine a time period for uniform heat distribution in test specimens and the mechanical properties of the investigated concrete composite, respectively. Both findings obtained from the presented experimental test as well as experimental data collected from scientific papers so far served for validating the computational accuracy of investigated stress-strain relations for HFRC which have been developed during last few years. Owing to the presence of steel and polypropylene fibers, HFRC becomes a unique material whose structural performance differs from conventional plain concrete when exposed to elevated temperature. Polypropylene fibers in HFRC lower the risk of concrete spalling as the fibers burn out shortly with increasing temperature due to low ignition point and as a consequence pore pressure decreases. On the contrary, the increase in the concrete porosity might affect the mechanical properties of the material. To validate this thought requires enhancing the existing result database which is very limited and does not contain enough data. As a result of the poor database, only few stress-strain relations have been developed so far to describe the structural performance of HFRC at elevated temperature. Moreover, many of them are inconsistent and need to be refined. Most of them also do not take into account the effect of both a fiber type and fiber content. Such approach might be vague especially when high amount of polypropylene fibers are used. Therefore, the existing relations should be validated in detail based on other experimental results., {"references":["Q. Ma, G. Rongxin, Z. Zhiman, L. Zhiwei and H. Kecheng, \"Mechanical properties of concrete at high temperature - a review,\" Construction and Building Materials, vol. 93, pp. 371–383, June 2015.","C. S. Poon, Z. H. Shui and L. Lam, \"Compressive behavior of fiber reinforced high-performance concrete subjected to elevated temperatures,\" Cement and Concrete Research, vol. 34, pp. 2215–2222, February 2004.","G. Peng, Y. Wen-Wu, J. Zhao, L. Ye-Feng, B. Song-Hua and L. Zhao, \"Explosive spalling and residual mechanical properties of fiber-toughened high-performance concrete subjected to high temperatures,\" Cement and Concrete Research, vol. 36, pp. 723-727, December 2006.","Y. Ding, C. Azevedo, J. B. Aguiar and S. Jalali, \"Study on residual behaviour and flexural toughness of fibre cocktail reinforced self compacting high performance concrete after exposure to high temperature,\" Construction and Building Materials, vol. 26, pp. 21-31, July 2011.","W. Zheng, H. Li and Y. Wang, \"Compressive behaviour of hybrid fiber-reinforced reactive powder concrete after high temperature,\" Materials and Design, vol. 41, pp. 403-409, May 2012.","A. Jameran, S. I. Izni, H. S. S. Yazan and S. N. A. A. Rahim, \"Mechanical properties of steel-polypropylene fibre reinforced concrete under elevated temperature,\" Procedia Engineering - The 5th International Conference of Euro Asia Civil Engineering Forum (EACEF-5), vol. 125, pp. 818 824, 2015.","D. Choumanidis, E. Badogiannis, P. Nomikos and A. Sofianos, \"The effect of different fibres on the flexural behaviour of concrete exposed to normal and elevated temperatures,\" Construction and Building Materials, vol. 129, pp. 266-277, November 2016","D. Xiangjun, D. Yining and W. Tianfeng, \"Spalling and Mechanical Properties of Fiber Reinforced High-performance Concrete Subjected to Fire,\" Journal of Wuhan University of Technology-Mater. Sci. Ed, pp. 743-749, October 2008.","W. Khaliq and V. Kodur, \"Thermal and mechanical properties of fiber reinforced high performance self-consolidating concrete at elevated temperatures,\" Cement and Concrete Research, vol. 41, pp. 1112-1122, June 2011.\n[10]\tS. Sanchayan and S. J. Foster, \"High temperature behaviour of hybrid steel–PVA fibre reinforced reactive powder concrete,\" Materials and Structures, vol. 46, pp. 769-782, January 2016.\n[11]\tJ. Novák and A. Kohoutková, \"Fire response of hybrid fiber reinforced concrete to high temperature,\" Procedia Engineering vol. 172, pp. 784-790, 2017.\n[12]\tP. Bamonte and P. G. Gambarova, \"Thermal and Mechanical Properties at High Temperature of a Very High-Strength Durable Concrete,\" Journal of Material in Civil Engineering, pp. 545 555, June 2010.\n[13]\tP. Bamonte and P. G. Gambarova, \"A study on the mechanical properties of self-compacting concrete at high temperature and after cooling,\" Materials and Structures, vol. 45, pp. 1375–1387, February 2012.\n[14]\tZ. Xing, A. Beaucour, R. Hebert, A. Noumowe and B. Ledesert, \"Influence of the nature of aggregates on the behaviour of concrete subjected to elevated temperature,\" Cement and Concrete Research, vol. 41, pp. 392-402, January 2011.\n[15]\tK. K. Sideris, P. Manita and E. Chaniotakis, \"Performance of thermally damaged fibre reinforced concretes,\" Construction and Building Materials, vol. 23, pp. 1232-1239, September 2009.\n[16]\tJ. Kim, G. P. Lee and D. Y. Moon, \"Evaluation of mechanical properties of steel-fibre-reinforced concrete exposed to high temperatures by double-punch test,\" Construction and Building materials, vol. 79, pp. 182-191, January 2015.\n[17]\tF. Aslani and B. Samali, \"High Strength Polypropylene Fibre Reinforcement Concrete at High Temperature,\" Fire Technology, vol. 50, pp. 1229-1247, 2014. \n[18]\tF. Aslani and B. Samali, \"Constitutive Relationships for Steel Fibre Reinforced Concrete at Elevated Temperatures,\" Fire Technology, vol.50, pp. 1249-1268, 2014.\n[19]\tW. Zheng, H. Li and Y. Wang, \"Compressive stress-strain relationship of steel fiber-reinforced reactive powder concrete after exposure to elevated temperatures,\" Construction and Building Materials, vol. 35, pp. 931-940, 2012.\n[20]\tY. S. Tai, H. H. Pan and Y. N. Kung, \"Mechanical properties of steel fiber reinforced reactive powder concrete following exposure to high temperature reaching 800°C,\" Nuclear Engineering and Design, pp. 2416-2424, 2011\n[21]\tL. Y. Li and J. Purkiss, \"Stress-strain constitutive equations of concrete material at elevated temperatures,\" Fire Safety Journal, vol. 40, pp. 669 686, 2005.\n[22]\tY.F. Chang, Y.H.Chen, M.S. Sheu and G.C.Yao,\" Residual stress-strain relationship for concrete after exposure to high temperatures,\" Cement and Concrete Research, vol.36, pp. 1999-2005, 2006.\n[23]\tM.A.Youssef and M. Moftah, \"General stress-strain relationship for concrete at elevated temperatures,\" Engineering Structures, vol. 29, pp. 2618-2634, 2007. \n[24]\tCSN EN 197-1 Cement - Part 1: Composition, specifications and conformity criteria for common cements, Urad pro technicku normalizaci, metrologii a statni zkusebnictvi (UNMZ), April 2012.\n[25]\tR. Serrano, A. Cobo, M. I. Prieto and M. de las N. González, \"Analysis of fire resistance of concrete with polypropylene or steel fibers,\" Construction and Building Materials, vol. 122, pp. 302-309, July 2016.\n[26]\tCSN EN 12390-3: Testing hardened concrete Part 3: Compressive strength of test specimens, Urad pro technicku normalizaci, metrologii a statni zkusebnictvi (UNMZ), 2009.\n[27]\tCSN EN 12390-6 Testing hardened concrete: Part 6 – Splitting tensile strength of test specimens, Urad pro technicku normalizaci, metrologii a statni zkusebnictvi (UNMZ), 2010.\n[28]\tA. Fina, F. Cuttica and Camino, G., \"Ignition of polypropylene/montmorillonite nanocomposites,\" Polymer Degradation and Stability, vol. 97, pp. 2619-2626, 2012.\n[29]\tCSN EN 1991-1-2 Eurocode 1: Actions on structures - Part 1-2: General actions - Actions on structures exposed to fire. Urad pro technicku normalizaci, metrologii a statni zkusebnictvi (UNMZ), November 2006.\n[30]\tInternational Federation for Structural Concrete (fib),\"Fib Model Code for Concrete Structures 2010,\" Berlin, Germany: Wilhelm Ernst & Sohn, Verlag für Architektur und technische Wissenschaften GmbH & Co. KG, 2013."]}

This paper focuses on issues of device navigation in a specific environment with the possibility of environment recognition, in which the device is currently located. The purpose of the paper is presentation of the system which could be a solution for autonomous navigation system of discussed types of devices for ground and aerial traffic. We are aware of the fact that similar products are available on the market. The aim of our work, which contains below described data preprocessing, is creation of such a distributed application that will be able to process publically available cartographical data and will enable orientation of the device in real 3D environment in different modes of operation.

In the present paper, a study of temperature behaviour of the liquid–liquid equilibrium in ternary systems N,N-dimethylformamide + 2-methylpentane + methanol and N,N-dimethylformamide + methylcyclohexane + methanol. The analysis of critical curves of the liquid–liquid equilibrium by means of the regular solution model was carried out. The acquired predictions were subsequently verified experimentally.

Liquid−liquid equilibrium and excess enthalpies were measured for the binary system 2-methylpentane + N,N-dimethylformamide. Equilibrium data were obtained at different temperatures by the direct analytical and volume methods; points of the binodal curve in the vicinity of the upper critical solution temperature of this system were acquired by means of the cloud-point method. Excess enthalpies were measured at 298.15 K and 313.15 K. Binary data were correlated by the modified Wilson equation. To estimate the critical composition and the upper critical solution temperature, the liquid-phase behavior data were also described by the extended scaling-law equation proposed by Ewing et al.5 The liquid−liquid equilibrium and excess enthalpies in the binary system were predicted by the modified UNIFAC (Dortmund) model so that the prediction could be compared to the experimentally achieved data.

In this paper relations between the shapes of the liquid–liquid critical curves in ternary systems and the temperature characters of the heterogeneous regions are discussed. The regular-solution model with temperature-dependent parameters was employed to describe critical curves of liquid–liquid equilibria in ternary systems. Relations for the limiting values of the slopes of critical curves were derived. The corresponding type of the critical curve and consequently the temperature character of the liquid–liquid equilibrium can be deduced from these values. Model calculations were performed for ternary systems characterised by two binary subsystems with either an upper critical solution temperature or with a lower critical solution temperature, and the third binary subsystem which is homogeneous in the considered temperature range. In the calculations the following approach was used: the behaviour of two binary systems was fixed by the temperature dependencies of their parameters and ternary critical curves of LLE were then calculated for variants differing in non-ideality (deviations from the Raoult’s law) of the third homogeneous binary subsystem. It was found that the level of non-ideality of the homogeneous system can influence the shape of the critical curve significantly.

Liquid−liquid equilibrium and excess enthalpies were studied for the two binary systems: methylcyclohexane + methanol and methylcyclohexane + N,N-dimethylformamide. Points of the binodal curve in ...

Liquid + liquid equilibrium was determined for three ternary systems water + ethanol + dialkyl phthalates (dimethyl, diethyl, and dibutyl phthalate) at 298.15 K. The turbidimetry titration method was used to obtain the binodal curves. Direct analytical methods were used to determine the composition of coexisting phases. The critical point composition was extrapolated from equilibrium data for each of the ternary systems using the Coolidge method. Excess enthalpy data were obtained for the system dimethyl phthalate + ethanol at 298.15 K. These, along with ternary and literature binary data, allowed a thorough thermodynamic description of the system water + ethanol + dimethyl phthalate. The modified Wilson equation was employed for this purpose.

Data on (liquid + liquid) equilibrium in (dimethyl phthalate + water), (diethyl phthalate + water), and (dibutyl phthalate + water) have been measured by direct analytical methods over the temperature range (283 to 323) K. Gas chromatography and spectrophotometric methods have been employed to determine the composition of the organic substances in the liquid phases. The water content in the organic liquid phases has been measured by means of the Karl–Fischer titration. A new l.l.e. measurement cell which allows samples to be analysed more easily and more precisely was constructed. The experimental data have been fitted by means of the modified Wilson equation using the maximum likelihood method.

Liquid-liquid equilibrium and excess enthalpies at 25, 40 and 60 °C were measured for the 4-methylpentan-2-one-water system. Vapour-liquid equilibrium at 115 °C and 99.96 kPa, and excess enthalpies at 25, 40 and 60 °C were determined for the 4-methylpentan-2-one- 4-methylpentan-2-ol system. The data obtained were correlated together with those given in literature using the superposition of the Wilson and Redlich-Kister equation. The correlation procedure utilised also the data on excess enthalpy measured in a heterogeneous region.

The surface tensions, interfacial tensions, and densities of conjugate solutions of compositions lying in the miscibility gap were measured for three ternary systems, viz. tert-butyl methyl ether-water-ethanol, tert-butyl methyl ether-water-tert-butyl alcohol, and tert-butyl methyl ether-water-butan-1-ol, at 25 °C.

The excess enthalpies measured in nitromethane-water and methyl tert-butyl ether-water systems at several temperatures are given. The values of the excess enthalpy were determined in both the homogeneous and heterogeneous regions. It is shown how the data for the heterogeneous region can be included in the calculation of parameters of empirical relations for the excess Gibbs energy. It follows from these calculations that the relations for the excess Gibbs energy can be obtained on the basis of the excess enthalpy data measured at several temperatures if the data also cover the heterogeneous region.

The paper is devoted to convergence of double sequences and its application to products. In a convergence space we recognize three types of double convergences and points, respectively. We give examples and describe their structure and properties. We investigate the relationship between the topological and convergence closure product of two Frechet spaces. In particular, we give a necessary and sufficient condition for the topological product of two compact Hausdorff Frechet spaces to be a Frechet space.

It was proved that the enthalpy of saturated vapour as a function of temperature has a maximum for all substances. The dependence of the entropy of saturated vapour on temperature can be monotonous, has a minimum and a maximum, or has only a maximum. The thermodynamic relations were derived for the existence of the extremes which enable their computation from the knowledge of dependence of the ideal-gas heat capacity on temperature and an equation of state. A method based on the theorem of corresponding states was proposed for estimating the extremes, and its results were compared with literature data. The agreement between the literature and estimated temperatures corresponding to the extremes is very good. The procedure proposed can serve for giving precision to the H-p and T-S diagrams commonly used in applied thermodynamics.

In this paper we describe the application of the finite element method (FEM) in modelling spatial distributions of electric and elastic fields in a ferroelectric crystals with two domains separated by a 90° domain wall. The domain boundary is idealized as a two-dimensional defect in an electro-elastic continuum. It represents the source of inhomogenity and internal distortion in both elastic and electric fields. The main results are distributions of electric field, strain and mechanical force along the domain boundary.

The vapour-liquid equilibrium at 101.32 kPa and the solid-liquid equilibrium were measured for the binary system phenol + tetrahydrofuran. In the ternary system phenol + tetrahydrofuran + water, liquid-liquid and solid-liquid equilibrium data were experimentally determined. Data on VLE, LLE and the heats of mixing were correlated simultaneously for each of the following binary subsystems: tetrahydrofuran + water, phenol + water and phenol + tetrahydrofuran. For this purpose, modified Wilson and NRTL equations were used. The ternary system shows a strong temperature dependence of the LLE which involves closed-loop curves of limited miscibility. The ternary LLE data were correlated with the modified Wilson and NRTL equations with a ternary correction that had to be applied to reach an adequate thermodynamic description.

This method is based on the oxidation of a known amount of iron(II) ions with oxide superconductors YBaCuO and BiSrCaCuO in a 2–5 mol l −1 solution of hydrobromic acid. The unreacted iron(II) ions were determined by cerimetric titration with ferroin as the indicator. This procedure allows the dissolution of samples even at elevated temperature. The reliability interval is 5%.

The liquid-liquid equilibrium was measured at 20 °C in the title quaternary system and in the three nitromethane-containing ternary subsystems. The data were compared with those predicted by a superposition of the Wilson and Redlich-Kister equations including the ternary parameters. The agreement between the observed and calculated data is very good both for the quaternary system and for the three ternary systems.