According to the most popular conceptualization of materialism by Richins and Dawson it consists of three components: acquisition centrality, acquisition as the pursuit of happiness and possession -defined success. They are usually combined and an overall indicator of materialism is used commonly in various studies. In the article the three components are examined separately. Differences in their nature are revealed in a theoretical analysis, whereas in two empirical studies the ways they connect with well -being are presented. The results show that the overall materialism explains much less variance of well -being than the three components taken separately. Of the three the possession-defined happiness is the most detrimental to all aspects of well -being. The possession -defined success does not connect with well -being at all. Finally, acquisition centrality elevates hedonic and psychological well -being. The conclusion is that the modest effect of materialism on well -being, usually identified in various studies, is probably at least partly due to conflicting forces existing within the construct.
This paper reviews research at the Institute of Materials Science and Engineering, Poznań University of Technology, on the synthesis of nanocrystalline hydride electrode materials. Nanocrystalline materials have been synthesized by mechanical alloying (MA) followed by annealing. Examples of the mate2-, LaNi5 and Mg2Ni-type phases. Details on the process used and the enhancement of properties due to the nanoscale structures are presented. The synthesized alloys were used as negative electrode materials for Ni-MH battery. The properties of hydrogen host materials can be modi?ed substantially by alloying to obtain the desired storage characteristics. For example, it was found that the respective replacement of Fe in TiFe by Ni and/or by Cr, Co, Mo improved not only the discharge capacity but also the cycle life of these electrodes. The hydrogen storage properties of nanocrystalline ZrV2- and LaNi5-type powders prepared by mechanical alloying and annealing show no big di?erence with those of melt casting (polycrystalline) alloys. On the other hand, a partial substitution of Mg by Mn orAl in Mg2Ni alloy leads to an increase in discharge capacity, at room temperature. Furthermore, the e?ect of the nickel and graphite coating on the structure of some nanocrystalline alloys and the electrodes characteristics were investigated. In the case of Mg2Ni-type alloy mechanical coating with graphite e?ectively reduced the degradation rate of the studied electrode materials. The combination of a nanocrystalline TiFe-, ZrV2- and LaNi5-type hydride electrodes and a nickel positive electrode to form a Ni-MH battery, has been successful.
Elaborated shapes of many car components are the reason for which the use of casting techniques to fabricate them is a solution wellfounded
from the economical point of view. Currently applicable regulatory requirements concerning emissions of exhaust fumes force the
carmakers to reduce the overall weight of their products, as this is a basic precondition for reducing fuel consumption. As a result, newly
launched car models contain a continuously increasing share of thin-walled castings made of materials which ensure a satisfactory level of
service properties. At the same time, developing new technological processes allowing to extend the service life of individual components
by means of surface improving becomes more and more important.
The paper contains a short literature review on the subject of special type of thin film structures with resistiveswitching memory effect. In the literature, such structures are commonly labeled as "memristors". The word "memristor" originates from two words: "memory" and "resistor". For the first time, the memristor was theoretically described in 1971 by Leon Chua as the 4th fundamental passive electronics element with a non-linear current-voltage behavior. The reported area of potential usage of memristor is enormous. It is predicted that the memristor could find application, for example in the domain of nonvolatile random access memory, flash memory, neuromorphic systems and so forth. However, in spite of the fact that plenty of papers have been published in the subject literature to date, the memristor still behaves as a "mysterious" electronic element. It seems that, one of the important reasons that such structures are not yet in practical use, is unsufficient knowledge of physical phenomena determining occurrence of the switching effect. The present paper contains a literature review of available descriptions of theoretical basis of the memristor structures, used materials, structure configurations and discussion about future prospects and limitations.
The technical requirements for the determination of physical parameters of vibration isolating material have not been standardized in Europe and Poland yet, which significantly hinders the ability to compare vibration isolating materials offered on the market. Therefore, there is a need for establishing a norm that could be applied both for the determination of the physico-mechanical properties of elastic vibration isolation elements in rail transport for domestic and foreign producers as well as in their selection for application in a specific vibration isolation system. The paper presents a proposal to standardize the methodology of the estimation of vibration isolation materials physical parameters authorized for use in vibration isolation systems used in rail transport. Methodology for measuring the physico-mechanical parameters of vibration isolating material presented in the paper forms uniform test procedure developed based on a fragmentary norms for flexible materials testing. The use of the proposed research methodology enables the creation of a unified database of elastic materials which parameters will be easy to compare, and choice between them will become easier for designers of vibration isolation systems used in rail transport.
One of the ways to decrease thermal conductivity is nano structurization. Cobalt triantimonide (CoSb3) samples with added indium or tellurium were prepared by the direct fusion technique from high purity elements. Ingots were pulverized and re-compacted to form electrodes. Then, the pulsed plasma in liquid (PPL) method was applied. All materials were consolidated using rapid spark plasma sintering (SPS). For the analysis, methods such as X-ray diffraction (XRD), scanning electron microscopy (SEM) and scanning transmission electron microscopy (STEM) with a laser flash apparatus (LFA) were used. For density measurement, the Archimedes’ method was used. Electrical conductivity was measured using a standard four-wire method. The Seebeck coefficient was calculated to form measured Seebeck voltage in the sample placed in a temperature gradient. The preparation method allowed for obtaining CoSb3 nanomaterial with significantly lower thermal conductivity (10 Wm–1K–1 for pure CoSb3 and 3 Wm–1K–1 for the nanostructured sample in room temperature (RT)). The size of crystallites (from SEM observations) in the powders prepared was about 20 nm, joined into larger agglomerates. The Seebeck coefficient, α, was about –200 µVK–1 in the case of both dopants, In and Te, in microsized material and about –400 µVK–1 for the nanomaterial at RT. For pure CoSb3, α was about 150 µVK–1 and it stood at –50 µVK–1 for nanomaterial at RT. In bulk nanomaterial samples, due to a decrease in electrical conductivity and inversion of the Seebeck coefficient, there was no increase in ZT values and the ZT for the nanosized material was below 0.02 in the measured temperature range, while for microsized In-doped sample it reached maximum ZT = 0.7 in (600K).
Rare earth metals including yttrium and europium are one of several critical raw materials, the use of which ensures the development of the so-called high technology. The possibility of their recovery in Europe is limited practically only to secondary materials such as phosphogypsum and electronic waste.
The article presents the results of our research concerning the development of recovery technology of yttrium and europium from luminophore CRT used lamps. It describes the principle of separation of elements and the test results of cleaning the concentrate. It was shown that the costs of preparing the concentrate according to the proposed technology are lower than the phosphogypsum processing technology and the composition of the resulting product does not contain hazardous substances.
Some physical concepts important for a hysteresis model (effective field, anhysteretic magnetization) are discussed on the example of Jiles-Atherton model. The Jiles-Atherton model reveals some drawbacks, which make this model more difficult to be applied in electrical engineering. In particular, it does not describe accurately the magnetization curves after a reversal, moreover complex magnetization cycles are poorly represented. On the other hand, the phenomenological description proposed by Takács seems to be a valuable alternative to the Jiles-Atherton formalism. The concept of effective field may be easily incorporated in the description.
The ceaseless progress of nanotechnology, observed in the last years, causes that nanomaterials are more and more often applied in several
fields of industry, technique and medicine. E.g. silver nanoparticles are used in biomedicine for disinfection and polymer nanoparticles
allow insulin transportation in pharmacology. New generation materials containing nanoparticles are also used in the chemical industry
(their participation in the commercial market equals app. 53 %). Nanomaterials are used in electronics, among others for semiconductors
production (e.g. for producing nanoink Ag, which conducts electric current).
Nanomaterials, due to their special properties, are also used in the foundry industry in metallurgy (e.g. metal alloys with nanocrystalline
precipitates), as well as in investment casting and in moulding and core sand technologies. Nanoparticles and containing them composites
are applied in several technologies including foundry practice, automotive industry, medicine, dentistry etc. it is expected that their role
and market share will be successively growing.
Horizontal centrifugal casting is an effective method for the production of hollow metal with good mechanical properties, low defect, cast
to size and relatively cheap. The ability of a metal to satisfy the above requirements highly depends on its microstructure. In this study, the
relationship between microstructural parameters such as grain size and the amount of phases with bulk hardness of SnCu4Pb3 is concerned
in three areas of the product. Consequently, to achieve the desired hardness of the product in a particular area, the interaction of two
factors of the microstructure including, grain size and particles amount of the hard intermetallic compositions (Cu6Sn5) should be noted.
We present the results of investigations of Pb(Fe1/2Nb1/2)O3 (PFN) ceramic samples obtained using two-step synthesis (i.e. columbite method). For obtained samples complex investigations of microstructure, magnetic and electrophysical properties have been performed at low and at high temperatures. Microstructure is characterized by small grains with high homogeneity and high density (low porosity). Impedance of samples and the phase shift angle have been measured using LCR Meter. Next the AC electric conductivity, dielectric permittivity and loss tangent have been calculated. AC conductivity at frequency 3 Hz was measured in similar way using Quantum Design PPMS System in magnetic fields 1000 Oe and 10000 Oe. At temperature range 240K-260K the anomalies of conductivity are observed. These anomalies depend on measuring cycle (heating, cooling) and magnetic field.
The quest for airframe weight reduction results in a careful dimensioning cross section areas of structural airframe components depending on the anticipated loading. In the case of flanges of polymeric laminate spars subjected to tension such a dimensioning can be done by means of appropriate ply dropping along the spar flanges. A method for an effective calculation of the number of plies that can be cut off at the cross-section under consideration without excessive stress concentration resulted has been presented. The method takes advantage of the Linear Fracture Mechanics tools combined with simple finite element calculations. In addition, experimental data needed can be easily obtained with the use of inexpensive specimens that are simple for manufacturing and testing.
A short overview of the developments of functional materials featuring miniaturisation and integration is illustrated by examples taken from the ?eld of ceramic functional materials. To obtain new materials new methods are required. Most of them are microfabrication processes developed by the "top-down" approach.
A great number of non-functional child care facilities for children up to the age of three have been created in Poland to this day. This state of affairs may be the consequence of the low level of knowledge in this field, as well as few available studies on topics associated with nursery facilities, which may familiarise readers with the legal aspects, administrative procedures, or examples of good functional and material solutions of such units. What is more, there is also little information about the needs and preferences of people directly related to the topic. The aim of the article is to analyse the expectations and preferences of nursery facilities’ users in terms of the functional and material solutions. Based on a survey conducted among the nurseries’ employees and parents placing their children in the care of such institutions, a number of guidelines has been defined, allowing for the design of an optimal nursery facility that would meet the market’s expectations.
The present article investigates theoretically the refection and transmission through a lossless dielectric slab embedded between two semi−infinite left−handed materials (LHMs) in which the electric permittivity and magnetic permeability are simultaneously negative. The LHM is assumed to be dispersive according to Lorentz as well as Drude medium model. The reflection and transmission coefficients are studied with the angle of incidence, frequency and slab thickness. The effect of the damping frequency is also investigated. It is found that the damping frequency has an insignificant effect on reflected, transmitted and loss powers. Band pass filter is one of the possible applications of the proposed structure.