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Number of results: 12
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Abstract

Despite many years of research, we have yet to discover all the myriad ways various components of the climate interact. For instance, it looks likely that the circulation of oceanic waters has a much broader impact than previously thought.
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Abstract

Transport properties of bronchial mucus are investigated by two-stage experimental approach focused on: (a) rheological properties and (b) mass transfer rate through the stagnant layer of solutions of mucus components (mucine, DNA, proteins) and simulated multi-component mucus. Studies were done using thermostated horizontal diffusion cells with sodium cromoglycate and carminic acid as transferred solutes. Rheological properties of tested liquids was studied by a rotational viscometer and a cone-plate rheometer (dynamic method). First part of the studies demonstrated that inter-molecular interactions in these complex liquids influence both rheological and permeability characteristics. Transfer rate is governed not only by mucus composition and concentration but also by hydrophobic/hydrophilic properties of transported molecules. Second part was focused on the properties of such a layer in presence of selected nanostructured particles (different nanoclays and graphene oxide) which may be present in lungs after inhalation. It was shown that most of such particles increase visco-elasticity of the mucus and reduce the rate of mass transfer of model drugs. Measured effects may have adverse impact on health, since they will reduce mucociliary clearance in vivo and slow down drug penetration to the bronchial epithelium during inhalation therapy.
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Abstract

The aim of this study was to determine the influence of feed on the pharmacokinetics of flumequine (FLU) administered to broiler chickens as follows: directly into the crop (10 mg/kg of BW) of fasted (group I/control) and non-fasted chickens (group II), or administered continu- ously with drinking water (1 g/L for 72 h) and with unlimited access to feed (group III). Plasma concentration of FLU was determined by high-performance liquid chromatography with fluo- rescence detection. In group II, a significant decrease in the maximum concentration (Cmax = 2.13±0.7 μg/mL) and the area under the concentration curve from zero to infinity (AUC0→∞ = 7.47±2.41 μg·h/mL) was noted as compared to the control group (Cmax = 4.11±1.68 μg/mL and AUC0→∞ = 18.17±6.85 μg·h/mL, respectively). In group III, the decrease in AUC was signifi- cant only in the first 3 hours (AUC0→3 = 5.02±1.34 μg·h/mL) as compared to the control group (AUC0→3 = 7.79±3.29 μg·h/mL). The results indicate that feed reduced the bioavailability of FLU from the gastrointestinal tract by at least 50% after the administration of a single oral dose. However, continuous administration of FLU with drinking water could compensate for the feed-induced decrease in absorption after single oral dose.
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Abstract

In this paper, effects of non-Fourier thermal wave interactions in a thin film have been investigated. The non-Fourier, hyperbolic heat conduction equation is solved, using finite difference method with an implicit scheme. Calculations have been carried out for three geometrical configurations with various film thicknesses. The boundary condition of a symmetrical temperature step-change on both sides has been used. Time history for the temperature distribution for each investigated case is presented. Processes of thermal wave propagation, temperature peak build-up and reverse wave front creation have been described. It has been shown that (i) significant temperature overshoot can appear in the film subjected to symmetric thermal load (which can be potentially dangerous for reallife application), and (ii) effect of temperature amplification decreases with increased film thickness.
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Abstract

The category of expectation constitutes an important element of reflection in many scientific disciplines focusing on man. it is treated in both the categories of expectations inscribed in large social projects (e.g. of utopian nature) and individual expectations which build human daily routine. The article is divided into two parts. in the first, the issues of interpersonal expectations, analysed in the perspective of social psychology and sociology, will be undertaken. what will be explored here are the problems of defining the notion of expectation and the problems of expectations at school, which will be exemplified by the pygmalion effect. The first part is completed with some considerations on the meaning of expectation in sociology, the role of expectations in interaction, and the relations between expecting and social order. In the second part, the author focuses on the issues of expectations inscribed in utopian projects (“great expectations”). pedagogical utopias and relations between utopias and popularization of normative (formal) or informal pedagogies are subjected to analysis. The author makes here some references to the concept of post-materialistic society, attempting to elicit relations between this type of society and popularization of nonformal pedagogies.
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Abstract

Red basil (Ocimum basilicum L.) cv. Red Rubin was cultivated in model pot experiment in the soil amended by arsenic, cadmium and lead solutions in stepwise concentrations representing the soil concentration levels of former mining area in the vicinity of Příbram, Czech Republic. The element levels added to the soil reached up to 40 mg Cd, 100 mg As, and 2000 mg Pb per kg of soil. Moreover, essential macro-and microelements as well as cyanidine contents were investigated to assess their potential interactions with the risk elements. The extractable element portions in soils determined at the end of vegetation period differed according to the individual elements. Whereas the plant-available (extractable with 0.11M CH3COOH) content of Cd represented 70-100% of the added Cd, the mobile portion of Pb did not exceed 1%. The risk element content in plants reflected the increasing element contents in soil. The dominant element portions remained in plant roots indicating the limited translocation ability of risk elements to the aboveground biomass of this plant species. Although the risk element contents in amended plants significantly increased, no visible symptoms of phytotoxicity occurred. However, the effect of enhanced risk element contents on the essential element uptake was assessed. Considering inter-element relationships, elevated sulphur levels were seen in amended plants, indicating its possible role of phytochelatin synthesis in the plants. Moreover, the molybdenum contents in plant biomass dropped down with increasing risk element uptake by plants confirming As-Mo and Cd-Mo antagonism. The increasing content of cyanidine in the plant biomass confirmed possible role of anthocyanins in detoxification mechanism of risk element contaminated plants and suggested the importance of anthocyanin pigments for risk element tolerance of plants growing in contaminated areas.
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Abstract

The article presents the main discoveries of Prof. Andrzej K. Tarkowski, which proved to be fundamental for modern mammalian developmental biology and also for progress in animal breeding and assisted reproduction. Among his achievements the most important are: the demonstration of regulative abilities of blastomeres isolated from early mammalian embryos, generation of first chimaeric mice, studies on mammalian parthenogenesis and establishment of blastomere electrofusion technique for production of tetraploid embryos. Studies on nucleocytoplasmic interactions in germ cells and early embryos contributed substantially to the development of mammalian cloning. Prof. Tarkowski’s work and discoveries provided a tremendous input to the contemporary developmental biology of mammals.
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Abstract

The main objective of the research presented in this paper is to enhance driver-passengers comfort of a vehicle that in turn leads to better vehicle safety and stability. The focus was put on studying the interior vibration and noise contributions originated from tire-road and engine-transmission subsystems, due to their significant impact on the dynamic performance of the vehicle. The noise and vibration measurements were recorded at the driver’s head position and on the driver legs room. Furthermore, the influence of different tire types and road surface textures on the vehicle interior noise and vibration were considered. The results indicate that the widely used conventional engine mounts and tires in commercial vehicles cannot fulfill the conflicting requirements for the best isolation concerning both road surface and engine-transmission induced excitations. The values of driver’s head position sound pressure level and floor vibration acceleration broadband averages originate for engine-transmission are lower than that for tire-road interaction. Furthermore, the values of RMS, crest factor, kurtosis and IRI for the vehicle waveform were estimated for vehicle speeds, tire types and road surface textures. Moreover, the percentage contribution for both interior noise and vibration originated from tire-road interaction is higher than the one from vehicle engine-transmission system in all the vehicle speed range, tire type and road surface texture considered.
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Abstract

Quality evaluation is very important for haptic rendering. In this paper, an objective evaluation method for a haptic rendering system based on haptic perception features is proposed. In the method, the haptic rendering process is compared to the real world perception process in a simple standardized procedure based on feature extraction and data analysis. A complete evaluation process for a simple haptic rendering task of pressing a virtual spring is presented as an example to explain the method in detail. Compared with the traditional objective method based on error statistics, the method is more concerned about the consistency of human subjective feelings rather than physical parameters, which makes the evaluation process more consistent with the haptic perception mechanism. The results of comparative analysis show that the method presented in this paper is simple, gives reliable results reflecting the consistency with subjective feeling and has a better discrimination ability for different kinds of devices and algorithms compared with the traditional evaluation methods.
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Abstract

Development of new or upgrading of existing airplanes requires many different analyses, e.g., thermal, aerodynamical, structural, and safety. Similar studies were performed during re-design of two small aircrafts, which were equipped with new turboprop engines. In this paper thermo-fluid analyses of interactions of new propulsion systems with selected elements of airplane skin were carried out. Commercial software based numerical models were developed. Analyses of heat and fluid flow in the engine bay and nacelle of a single-engine airplane with a power unit in the front part of the fuselage were performed in the first stage. Subsequently, numerical simulations of thermal interactions between the hot exhaust gases, which leave the exhaust system close to the front landing gear, and the bottom part of the fuselage were investigated. Similar studies were carried out for the twin-engine airplane with power units mounted on the wings. In this case thermal interactions between the hot exhaust gases, which were flowing out below the wings, and the wing covers and flaps were studied. Simulations were carried out for different airplane configurations and operating conditions. The aim of these studies was to check if for the assumed airplane skin materials and the initially proposed airplane geometries, the cover destruction due to high temperature is likely. The results of the simulations were used to recommend some modifications of constructions of the considered airplanes.
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Abstract

To achieve better precision of features generated using the micro-electrical discharge machining (micro-EDM), there is a necessity to minimize the wear of the tool electrode, because a change in the dimensions of the electrode is reflected directly or indirectly on the feature. This paper presents a novel modeling and analysis approach of the tool wear in micro-EDM using a systematic statistical method exemplifying the influences of capacitance, feed rate and voltage on the tool wear ratio. The association between tool wear ratio and the input factors is comprehended by using main effect plots, interaction effects and regression analysis. A maximum variation of four-fold in the tool wear ratio have been observed which indicated that the tool wear ratio varies significantly over the trials. As the capacitance increases from 1 to 10 nF, the increase in tool wear ratio is by 33%. An increase in voltage as well as capacitance would lead to an increase in the number of charged particles, the number of collisions among them, which further enhances the transfer of the proportion of heat energy to the tool surface. Furthermore, to model the tool wear phenomenon, a egression relationship between tool wear ratio and the process inputs has been developed.
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Abstract

We consider fiscal and monetary policy interactions in a monetary unionunder monetary leadership, when the common central bank is concerned with theaverage fiscal stance of the union. We use a static two-country monetary unionmodel to investigate the policy-mix problem under different regimes of non-cooperation, cooperation, and enforced cooperation among fiscal authorities.We find that fiscal policy is unambiguously countercyclical, a feature that ismore pronounced under fiscal policy cooperation. Monetary policy can be eithercountercyclical or procyclical. A central bank concerned about the aggregatefiscal stance is effective in stabilizing output and central budget, but at theexpense of inflation stabilization.
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