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Number of results: 25
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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

The experiment consisted in monitoring the count of moulds and three selected Trichoderma sp. isolates (T1 - Trichoderma atroviride, T2 - Trichoderma harzianum, T3 - Trichoderma harzianum) in vegetable (onion and tomato) waste composted with additives (straw, pig manure). Additionally, the aim of the study was to determine the type of interaction occurring between autochthonous fungi isolated from composts after the end of the thermophilic phase and Trichoderma sp. strains applied in the experiment. Number of microorganisms was determined by the plate method, next the identification was confirmed. The rating scale developed by Mańka was used to determine the type of interactions occurring between microorganisms. The greatest count of moulds in onion waste composts was noted in the object which had simultaneously been inoculated with two strains T1 - T. atroviride and T3 - T. harzianum. The greatest count of moulds was noted in the tomato waste composts inoculated with T2 - T. harzianum strain. Microscope identification revealed that Penicillum sp., Rhizopus sp., Alternaria sp. and Mucor sp. strains were predominant in onion waste composts. In tomato waste composts Penicillium was the predominant genus, followed by Rhizopus. The test of antagonism revealed the inhibitory effect of Trichoderma isolates on most autochthonous strains of moulds. Tomato waste composts proved to be better substrates for the growth and development of Trichoderma sp. isolates. The results of the study show that vegetable waste can be used in agriculture as carriers of antagonistic microorganisms.
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Abstract

The aim of the performed experiments was to analyse relationships occurring between endophytic bacteria from the Herbaspirillum genus and Sinorhizobium meliloti Bp nodule bacteria and to examine the condition of plants subjected to coinoculation with the above-mentioned strains in in vitro conditions. In experiments examining the impact of Herbaspirillum frisingense on Sinorhizobium meliloti BP, the stimulation of growth of inoculated bacteria from the Sinorhizobium genus was recorded in all three combinations (48-hour culturing, sediment and supernatant). On the other hand, the examination of interactions between the Sinorhizobium meliloti strain and Herbaspirillum frisingense strain revealed that in the case of culture and supernatant, an antagonistic action was recorded. Besides, it was found that such coinoculation exerted a beneficial influence on the process of seed lucerne symbiosis and yielding as confirmed by increased numbers of root nodules, higher nitrogenase activity and greater plant mass.
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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

The paper presents selected results of studies connected with modeling of a biological object which could be used for simulation and measurements of the selected human tissues optical transmittance. The studies were performed for transilluminated homogeneous tissue layers as well as for objects consisted of different tissues. During simulations the software built with LabVIEW environment was used. Experimental verification of the model structure was made with spectrophotometry. The presented examples of modeling concern the transmittance spectra for two selected specific objects: the venous blood and muscle tissue analyzed in the wavelength range extending from 360 nm to 900 nm. The implemented model could be used in estimating the content and thickness of particular layers distinguished in a complex object and prediction of their transillumination efficiency.
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Abstract

Automation in experiments carried out on animals is getting more and more important in research. Computers take over laborious and time-consuming activities like recording and analysing images of the experiment scene. The first step in an image analysis is finding and distinguishing between the observed animals and then tracking all objects during the experiment. In this paper four tracking methods are presented. Quantitative and qualitative figures of merit are applied to confront those methods. The comparison takes into consideration the level of correct object recognition during different disturbances, the speed of computation, requirements as to the frame rate and image illumination, quality of recovering from occluded situations and others.
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Abstract

Traffic related noise is currently considered as an environmental pollution. Paper presents results of multidirectional study attempting to serve urban traffic without the need to erect noise barriers interfering urban space. Initial concept of the road expansion included construction of 1000 m of noise barriers dividing city space. Improvement in the acoustic conditions after construction completion is possible due to the applied noise protection measures: vehicle speed limit, smooth of traffic flow, use of road pavement of reduced noise emission and the technical improvement of the tramway.
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Abstract

The paper proposes a study of molecular interactions using the planetary model of the atomic structure. The description refers to transfer of the interactions by electrons bonded with an atom in a planetary system. In molecules we refer to analysis of electrons that remain unpaired during the formation of chemical compounds. The planetary electronic state of molecular interactions is defined by considering the action arm for interatomic forces. Then the interaction torque is defined. The problem is studied in a collection of atoms forming a nanoparticle and then analysis is carried on in the entire volume of the nanocomposite, which is defined as a set of the nanoparticles in a field of matrix-nanofiller interactions. As a result, new mechanical, magnetic, and optical properties of the nanocomposite arise and are described herein. The atomic-scale phenomena are described by both classical and quantum mechanics and are then transferred to the nanoparticle scale by applying statistical mechanics. The quantum solutions for the optically active electrons form the basis for the optical properties of the nanocomposite using forced gyrobirefringence and Maxwell equations. The results of the theoretical analysis are confirmed by experiment using an electron paramagnetic resonance spectrometer.
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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

Weak value amplification is a measurement technique where small quantum mechanical interactions are amplified and manifested macroscopically in the output of a measurement apparatus. It is shown here that the linear nature of weak value amplification provides a straightforward comparative methodology for using the value of a known small interaction to estimate the value of an unknown small interaction. The methodology is illustrated by applying it to quantify the unknown size of an optical Goos-Hänchen shift of a laser beam induced at a glass/gold interface using the known size of the shift at a glass/air interface.
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Abstract

Communication noise is classified as one of the pollutions for the current environment. Experimental techniques to measure tire-pavement noise generation from asphalt pavements in the laboratory have been limited. A series of experiments were conducted on six different asphalt mixtures to determine if Purdue University’s Tire-Pavement Test Apparatus (TPTA) could be used to overcome these limitations. The procedure produced samples with low tire-pavement noise; however, the air void contents of the samples were higher than designed. Despite these difficulties, the sample preparation technique and the TPTA testing protocol were shown to offer an effective approach for quick laboratory assessment of tire-pavement noise characteristics of hot mix asphalt pavements at a substantially reduced cost compared to field testing.
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Abstract

A review is given on a number of colloidal phenomena with special reference to their applicability to nanoparticles. Phenomena addressed include preparation, electric double layers and their characterization, electrokinetics, van der Waals and Lifshits forces, electric and steric particle interaction.
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Abstract

The paper describes the influence of the machining operation on a surface, which disturbs the projection of the tool profile in the form of its relative movements with respect to the object. The elements of the machine tool undergo constant wear during the machining process, it is therefore important to recognize the effects of their influence on the surface's irregularities. Amplitude-frequency analysis of lateral profiles has been used to evaluate and changes of turned lateral profiles. The results of simulation of radial and axial effects of the machine tool on surface and their spectral components were analyzed. Surfaces obtained in similar machining conditions on lathes operated in various time periods were analyzed spectrally. From the analysis of surface irregularity changes caused by disturbances in movements of the tool against the object, testifying the wear of main machine elements during its operation, the modulated, amplitude-frequency character of changes in surface irregularities of workpiece can be noticed.
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Abstract

The aim of the present study was to investigate the sensitivity of a multiphase Eulerian CFD model with respect to relations defining drag forces between phases. The mean relative error as well as standard deviation of experimental and computed values of pressure gradient and average liquid holdup were used as validation criteria of the model. Comparative basis for simulations was our own data-base obtained in experiments carried out in a TBR operating at a co-current downward gas and liquid flow. Estimated errors showed that the classical equations of Attou et al. (1999) defining the friction factors Fjk approximate experimental values of hydrodynamic parameters with the best agreement. Taking this into account one can recommend to apply chosen equations in the momentum balances of TBR.
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Abstract

The application of artificial intelligence (AI) in modeling of various machining processes has been the topic of immense interest among the researchers since several years. In this direction, the principle of fuzzy logic, a paradigm of AI technique, is effectively being utilized to predict various performance measures (responses) and control the parametric settings of those machining processes. This paper presents the application of fuzzy logic to model two non-traditional machining (NTM) processes, i.e. electrical discharge machining (EDM) and electrochemical machining (ECM) processes, while identifying the relationships present between the process parameters and the measured responses. Moreover, the interaction plots which are developed based on the past experimental observations depict the effects of changing values of different process parameters on the measured responses. The predicted response values derived from the developed models are observed to be in close agreement with those as investigated during the past experimental runs. The interaction plots also play significant roles in identifying the optimal parametric combinations so as to achieve the desired responses for the considered NTM processes.
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Abstract

The most important task in tests of resistance of aircraft structures to the terorist threats is to determine the vulnerability of thin-walled structures to the blast wave load. For obvious reasons, full-scale experimental investigations are carried out exceptionally. In such cases, numerical simulations are very important. They make it possible to tune model parameters, yielding proper correlation with experimental data. Basing on preliminary numerical analyses - experiment can be planned properly. The paper presents some results of dynamic simulations of finite element (FE) models of a medium-size aircraft fuselage. Modeling of C4 detonation is also discussed. Characteristics of the materials used in FE calculations were obtained experimentally. The paper describes also the investigation of sensitivity of results of an explicit dynamic study to FE model parameters in a typical fluid-structure interaction (FSI) problem (detonation of a C4 explosive charge). Three cases of extent of the Eulerian mesh (the domain which contains air and a charge) were examined. Studies have shown very strong sensitivity of the results to chosen numerical models of materials, formulations of elements, assumed parameters etc. Studies confirm very strong necessity of the correlation of analysis results with experimental data. Without such a correlation, it is difficult to talk about the validation of results obtained from "explicit" codes.
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Abstract

We apply a fluid-structure interaction method to simulate prototypical dynamics of the aortic heart-valve. Our method of choice is based on a monolithic coupling scheme for fluid-structure interactions in which the fluid equations are rewritten in the 'arbitrary Lagrangian Eulerian' (ALE) framework. To prevent the backflow of structure waves because of their hyperbolic nature, a damped structure equation is solved on an artificial layer that is used to prolongate the computational domain. The increased computational cost in the presence of the artificial layer is resolved by using local mesh adaption. In particular, heuristic mesh refinement techniques are compared to rigorous goal-oriented mesh adaption with the dual weighted residual (DWR) method. A version of this method is developed for stationary settings. For the nonstationary test cases the indicators are obtained by a heuristic error estimator, which has a good performance for the measurement of wall stresses. The results for prototypical problems demonstrate that heart-valve dynamics can be treated with our proposed concepts and that the DWR method performs best with respect to a certain target functional.
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Abstract

Development of complex lubrication systems in the Oil&Gas industry has reached high levels of competitiveness in terms of requested performances and reliability. In particular, the use of HazOp (acronym of Hazard and Operability) analysis represents a decisive factor to evaluate safety and reliability of plants. The HazOp analysis is a structured and systematic examination of a planned or existing operation in order to identify and evaluate problems that may represent risks to personnel or equipment. In particular, P&ID schemes (acronym of Piping and Instrument Diagram according to regulation in force ISO 14617) are used to evaluate the design of the plant in order to increase its safety and reliability in different operating conditions. The use of a simulation tool can drastically increase speed, efficiency and reliability of the design process. In this work, a tool, called TTH lib (acronym of Transient Thermal Hydraulic Library) for the 1-D simulation of thermal hydraulic plants is presented. The proposed tool is applied to the analysis of safety relevant components of compressor and pumping units, such as lubrication circuits. Opposed to the known commercial products, TTH lib has been customized in order to ease simulation of complex interactions with digital logic components and plant controllers including their sensors and measurement systems. In particular, the proposed tool is optimized for fixed step execution and fast prototyping of Real Time code both for testing and production purposes. TTH lib can be used as a standard SimScape-Simulink library of components optimized and specifically designed in accordance with the P&ID definitions. Finally, an automatic code generation procedure has been developed, so TTH simulation models can be directly assembled from the P&ID schemes and technical documentation including detailed informations of sensor and measurement system.
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Abstract

In this work we discuss 3D selfconsistent solution of Poisson and Schrödinger equations for electrostatically formed quantum dot. 3D simulations give detailed insight into the energy spectrum of the device and allow us to find values of respective voltages ensuring given number of electrons in the dot. We performed calculations for fully 3D potential and apart from that calculations for the same potential separated into two independent parts, i.e. regarding to the plane of 2DEG and to the direction perpendicular to the meant plane. We found that calculations done for the two independent parts of the potential give good information about quantum dot properties and they are much faster compared to fully 3D simulations.
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Abstract

Virtual or active acoustics refers to the generation of a simulated room response by means of electroacoustics and digital signal processing. An artificial room response may include sound reflections and reverberation as well as other acoustic features mimicking the actual room. They will cause the listener to have an impression of being immersed in virtual acoustics of another simulated room that coexists with the actual physical room. Using low-latency broadband multi-channel convolution and carefully measured room data, optimized transducers for rendering of sound fields, and an intuitive touch control user interface, it is possible to achieve a very high perceived quality of active acoustics, with a straightforward adjustability. The electroacoustically coupled room resulting from such optimization does not merely produce an equivalent of a back-door reverberation chamber, but rather a fully functional complete room superimposed on the physical room, yet with highly selectable and adjustable acoustic response. The utility of such active system for music recording and performance is discussed and supported with examples.
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Abstract

Two vibrating circular membranes radiate acoustic waves into the region bounded by three infinite baffles arranged perpendicularly to one another. The Neumann boundary value problem has been investigated in the case when both sources are embedded in the same baffle. The analyzed processes are time harmonic. The membranes vibrate asymmetrically. External excitations of different surface distributions and different phases have been applied to the sound sources’ surfaces. The influence of the radiated acoustic waves on the membranes’ vibrations has been included. The acoustic power of the sound sources system has been calculated by using a complete eigenfunctions system.
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