Currently, the “Lamarckian dimension” and “Lamarckian mechanisms” are vividly discussed, indicating that they are compatible with Darwinism. However, they require an extension of Modern Synthesis to Extended Evolutionary Synthesis. Both the terms, unfortunately connected to Lamarck, really indicate a group of phenomena which can be symbolized by Jablonka’s wording: “some evolutionary changes are non-random in origin, or even result from instruction.” The Lamarckian mechanisms leading to these evolutionary changes arose, however, in the Darwinian way much earlier. This earlier stage is said too rarely, and the typical understanding of Lamarckism strongly suggests its lack. The term “Lamarckism” was and is understood very differently both at different times and in different national and ideological traditions but usually fraught with a simplified understanding of Lamarck. Most of the controversies in these issues arise from the insufficient precision of the utterance, and this from undervaluation of definition, specification of assumptions and abstract reasoning.
Moving with the wheelchair can be a serious problem, especially when the obstacle occurs on its way. An alternative solution would be to equip the wheelchair with appropriate mechanical device, thanks to that it becomes possible to overcome barriers such as kerbs or doorsteps. In this paper, the authors present an idea of mechanism overcoming barriers by the wheelchair. Type and geometrical synthesis have been presented. The mechanism is modelled in a multibody computer analysis system and sample simulation research results are reported.
Attempts to perform synthesis of a passive vibroinsulation two-mass system intended for the simultaneous reduction of machine frame vibrations and forces transmitted to foundations by supporting elements were undertaken in the study. In view of the variable frequency of the machine operation, it was necessary for the frequency interval, encompassed by the vibroinsulation system operation, to be within given limits. On the grounds of properties of the linear massive-elastic system formulated in the works of Genkin and Ryaboy (1998), the problem of vibroinsulation system synthesis was formulated in the parametric type optimisation approach with equality and inequality limitations. For piston compressor vibroinsulation, the mass and elasticity matrices of the vibroinsulating system, as well as its physical structure, were determined. Its operation was verified on the basis of simulation investigations, taking into account the system loss and transient states.
The text was created on the basis of interviews with Caltech scholars (Pasadena, USA) in 2018. The talks concerned various contemporary theories of biogenesis and the role of their philosophical premises. The researchers also addressed the issue of popularizing science. The worldview is shaped (and established) by popularizing publications. They also answered the questions how their personal beliefs influenced on research.
The paper deals with linear circuits synthesis with periodic parameters. It was proved that the time-varying voltages and currents of inner branches of such circuits can be calculated using linear recursive equations with periodic coefficients if signals on port are given. The stability theorem of periodic solution was formulated. Hereby described the synthesis problems appear when compensation of power supply systems is considered.
In the paper the squared voltage-current functionals are minimized, which represent the global power losses in the network. In that way it is possible to find the voltage-current distributions on the net without the use of immitance operators and basing only on the Kirchhoff laws. Farther the individual branch parameters are defined in the syntheses process. Many optimal power analysis examples are also shown to illustrate the thesis included in the paper.
This paper presents an innovative method of technology mapping of the circuits in ALM appearing in FPGA devices by Intel. The essence of the idea is based on using triangle tables that are connected with different configurations of blocks. The innovation of the proposed method focuses on the possibility of choosing an appropriate configuration of an ALM block, which is connected with choosing an appropriate decomposition path. The effectiveness of the proposed technique of technology mapping is proved by experiments conducted on combinational and sequential circuits.
Nano-sized yttria (Y2O3) powders were synthesized by a polymer solution route using polyvinyl alcohol (PVA) as an organic carrier. The PVA polymer affected the dispersion of yttrium ions in precursor sol. In this study, three kinds of PVA polymer (different molecular weight) were applied for synthesis of yttria powder. The PVA type as well as calcination temperature had a strongly influence on the particle morphology. Single crystal nano wire particles were observed at the temperature of polymer burn out range and the size was dependent on the PVA type. The stable, fully crystallized yttria powder was obtained through the calcination at 800°C for 1 h. The yttria powder prepared with the high weight PVA (MW: 153,000) revealed a particle size of 30 nm with a surface area of 18.8 m2/g.
In the article, the characterization of the microstructure, phase composition and distribution of elements in the Eu2O3-ZrO2 sintered materials obtained by four different ways of powders’ homogenization (mixing) process and different temperature of sintering process is shown. The feedstock powders with an average mole ratio of ZrO2 to Eu2O3 equal 74% to 26% were used as an initial material. The principal aim of the investigation was characterization of differences in the microstructure of the same type of ceramics, however, prepared via different mixing and manufacturing processes. The range of the investigation covered a characterization of these materials via phase identification of all samples by XRD (X-ray diffraction) and characterization of internal morphology of the specimens with detailed analysis of elements distributions by SEM (scanning electron microscopy) and EDS (energy dispersive spectrometry). The aim of the following investigation is to characterize the possibilities of the solid state synthesis of the europium zirconate based materials, dedicated for TBC applications.
Polish Academy of Sciences, Institute of Chemical Engineering, 44-100 Gliwice, Bałtycka 5, Poland A review concerning main processes of hydrogenation of carbon oxides towards synthesis of methanol, mixture of methanol and higher aliphatic alcohols and one-step synthesis of dimethyl ether as well as methanol steam reforming is given. Low-temperature methanol catalysts and lowtemperature modified methanol catalysts containing copper as primary component and zinc as secondary one are described.
Available methods for room-related sound presentation are introduced and evaluated. A focus is put on the synthesis side rather than on complete transmission systems. Different methods are compared using common, though quite general criteria. The methods selected for comparison are: Intensity Stereophony after Blumlein, vector-base amplitude panning (VBAP), 5.1-Surround and its discrete-channel derivatives, synthesis with spherical harmonics (Ambisonics, HOA), synthesis based on the boundary method, namely, wave-field synthesis (WFS), and binaural-cue selection methods (e.g., DiRAC). While VBAP, 5.1-Surround and other discrete-channel-based methods show a number of practical advantages, they do, in the end, not aim at authentic sound-field reproduction. The so-called holophonic methods that do so, particularly, HOA and WFS, have specific advantages and disadvantages which will be discussed. Yet, both methods are under continuous development, and a decision in favor of one of them should be taken from a strictly application-oriented point of view by considering relevant application-specific advantages and disadvantages in detail.
Electromagnetic arrangements which create a magnetic field of required distribution and magnitude are widely used in electrical engineering. Development of new accurate designing methods is still a valid topic of technical investigations. From the theoretical point of view the problem belongs to magnetic fields synthesis theory. This paper discusses a problem of designing a shape of a solenoid which produces a uniform magnetic field on its axis. The method of finding an optimal shape is based on a genetic algorithm (GA) coupled with Bézier curves.
Because of excellent properties, similar to natural bone minerals, and variety of possible biomedical applications, hydroxyapatite (HAp) is a valuable compound among the calcium phosphate salts. A number of synthesis routes for producing HAp powders have been reported. Despite this fact, it is important to develop new methods providing precise control over the reaction and having potential to scale-up. The main motivation for the current paper is a view of continuous synthesis methods toward medical application of produced hydroxyapatite, especially in the form of nanoparticles.
Preparation and properties of hierarchically structured porous silica monoliths have been discussed from the viewpoint of their application as continuous microreactors for liquid-phase synthesis of fine chemical in multi kilogram scales. The results of recent topical papers published by two research teams of Institute of Chemical Engineering Polish Academy of Sciences (ICE) and Department of Chemical Engineering and Process Design, Chemical Faculty, Silesian University of Technology (SUT) have been analyzed to specify the governing traits of microreactors. It was concluded that even enhancement factor of 100 in activity, seen in enzyme catalyzed reactions, can be explained by a proportional reduction of its physical constraints, i.e. huge enhancement of external mass transfer and micromixing. It is induced by very chaotic flows of liquid in tens of thousands of waving connected channels of ca. 25–50 mm in diameter, present in the skeleton. The scale of enhancement in the case of less active catalysts was smaller, but still large enough to consider the most practical applications.
In this paper a two-disc spinning disc reactor for intensified biodiesel synthesis is described and numerically simulated. The reactor consists of two flat discs, located coaxially and parallel to each other with a gap of 0.2 mm between the discs. The upper disc is located on a rotating shaft while the lower disc is stationary. The feed liquids, triglycerides (TG) and methanol are introduced coaxially along the centre line of rotating disc and stationary disc. Fluid hydrodynamics in the reactor for synthesis of biodiesel from TG and methanol in the presence of a sodium hydroxide catalyst are simulated, using convection-diffusion-reaction species transport model by the CFD software ANSYS©Fluent v. 13.0. The effect of the upper disc’s spinning speed is evaluated. The results show that the rotational speed increase causes an increase of TG conversion despite the fact that the residence time decreases. Compared to data obtained from adequate experiments, the model shows a satisfactory agreement.
The results of activity studies of four catalysts in methanol synthesis have been presented. A standard industrial catalyst TMC-3/1 was compared with two methanol catalysts promoted by the addition of magnesium and one promoted by zirconium. The kinetic analysis of the experimental results shows that the Cu/Zn/Al/Mg/1 catalyst was the least active. Although TMC-3/1 and Cu/Zn/Al/Mg/2 catalysts were characterised by a higher activity, the most active catalyst system was Cu/Zn/Al/Zr. The activity calculated for zirconium doped catalyst under operating conditions was approximately 30% higher that of TMC-3/1catalyst. The experimental data were used to identify the rate equations of two types - one purely empirical power rate equation and the other one - the Vanden Bussche & Froment kinetic model of methanol synthesis. The Cu/ZnO/Al2O3 catalyst modified with zirconium has the highest application potential in methanol synthesis.
A rotor-stator spinning disk reactor for intensified biodiesel synthesis is described and numerically simulated in the present research. The reactor consists of two flat disks, located coaxially and parallel to each other with a gap ranging from 0.1 mm to 0.2 mm between the disks. The upper disk is located on a rotating shaft while the lower disk is stationary. The feed liquids, triglycerides (TG) and methanol are injected into the reactor from centres of rotating disk and stationary disk, respectively. Fluid hydrodynamics in the reactor for synthesis of biodiesel from TG and methanol in the presence of a sodium hydroxide catalyst are simulated, using convection-diffusion-reaction multicomponent transport model with the CFD software ANSYS©Fluent v. 13.0. Effect of operating conditions on TG conversion is particularly investigated. Simulation results indicate that there is occurrence of back flow close to the stator at the outlet zone. Small gap size and fast rotational speed generally help to intensify mixing among reagents, and consequently enhance TG conversion. However, increasing rotational speed of spinning disk leads to more backflow, which decreases TG conversion. Large flow rate of TG at inlet is not recommended as well because of the short mean residence time of reactants inside the reactor.
Two different complexing agents, namely citric acid and gelatin, were used for gel-combustion synthesis of yttria stabilized zirconia. The influence of synthesis conditions on properties of powders and sintered bodies was studied by X-ray Diffraction Analysis (XRD), Scanning Electron Microscope (SEM) and helium pycnometer measurements.