56 research outputs found
The Development of Postmaterialism in the Czech Republic
Tato práce analyzuje vývoj postmaterialismu v České republice. Konkrétně se zabývá vlivy, které mohly způsobit mírný pokles mezi měřeními v letech 1999 a 2008. V teoretické části práce je představeno základní pojetí postmaterialismu, jak ho vymezil Ronald Inglehart, a také vybraná kritika konceptu. Druhou částí práce je explorativní analýza výzkumů European Value Study, která ukazuje, že v české populaci je stále přítomen generační růst úrovně postmaterialismu a že pokles je pravděpodobně nejvíce ovlivněn ekonomickou situací v běžném životě respondentů. Na základě teorie a explorativní analýzy jsou stanoveny tři hypotézy vlivu na vývoj postmaterialismu v České republice mezi let 1999 a 2008. První hypotéza o mediálním vlivu finanční krize byla falsifikována. Následující hypotézy o vlivu inflace a cen pohonných hmot na postmaterialismus falsifikovány nebyly a je nutné je zohlednit. Závěry mají hlavně metodologický charakter, kdy je upozorněno na vliv kontextu dotazování při vývoji postmaterialismu.This thesis analyzes the development of postmaterialism in the Czech Republic. Specifically, it deals with the effects that might cause a slight decrease between measurements in 1999 and 2008. The theoretical part of the thesis presents basic concepts of postmaterialism, as defined by Ronald Inglehart, and selected critique of the concept. The second part is an exploratory analysis of research European Value Study, which shows that there is still present a generational growth of postmaterialism. in Czech population and that the decrease is likely to be most affected by the economic situation in the everyday life of the respondents. Based on the theory and exploratory analysis three hypotheses are formulated about the influences on the development of postmaterialism in the Czech Republic between 1999 and 2008. The first hypothesis about the media impact of the financial crisis has been falsified. The following hypotheses about the effects of inflation and fuel prices to postmaterialism have not been falsified and must be taken into account. The conclusions have mainly methodological character, which is claimed to affect the context of questioning the development of postmaterialism.Department of SociologyKatedra sociologieFaculty of ArtsFilozofická fakult
Graphene oxide membranes for gas separation
Recently, the carbon based materials1 attracted attention of the scientific community for applications in membrane gas separation. Tremendous number of carbon based materials such as carbon nanotubes, chemically modified graphene, graphene oxide (GO) or graphite (nano)particles in mixed matrix membrane (MMM) composites was tested within past decade2. It was found that even small loading of graphene and (GO) additives, i.e. 0.05 to 1 wt.%3, led to considerable changes of composite materials properties (elastic modulus, tensile strength, electrical conductivity, and thermal stability) compared to neat polymers.
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Aging of polymers of intrinsic microporosity studied by sorption and permeation
Polymers of intrinsic microporosity (PIMs)1 seem to be effective materials for gas and vapor separations.2 However, gas separation efficiency of PIMs can be strongly influenced by the material aging process connected with the changes of PIMs inner structure.3 With respect to potential industrial applications, the investigation of such changes and their effect on gas and vapor transport is necessary. In this work, we present a detailed study of i) CO2 sorption in PIM-1 via momentary measurements during four years and ii) methanol permeation in PIM-11 and EA-TB-PIM2 via continuous and momentary experiments. Sorption experiments were performed gravimetrically using a self-developed apparatus equipped with McBain’s spiral balances. In this case, PIM-1 membranes were pre-treated (soaking in ethanol with consequent drying at different temperatures) in order to study the influence of temperature on PIM-1 aging. Methanol permeation experiments were performed using a differential flow permeameter with H2 and He as carrier gases. Permeation experiment were performed with PIM-1 and PIM-EA-TB methanol treated membranes. CO2 sorption measurements revealed that, assuming the validity of the solution-diffusion model, the decrease of permeability during aging can be attributed directly to the decrease of diffusivity, whereas solubility is time independent in the studied period of four years. Although higher preparation temperature led to the initial drop of diffusivity, this process stabilized separation performance of PIMs over time (Figure 1). MeOH permeation experiments confirmed previous findings from CO2 tests, that the permeability decrease during the aging is a diffusivity controlled process. Moreover, it was found that the momentary permeation data can be mathematically transferred to continuous data, which are more relevant for applications but more difficult to measure. The nature of aging process was studied by infrared spectroscopy. We have found that aging of PIMs does not influence their chemical structure and; therefore, they undergo only the so called physical-aging.
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Comparison of temperature and oxygen concentration driven aeration methods for biodrying of municipal solid waste
In this study, we used a model bio drying reactor to optimize the drying of municipal solid waste (MSW). Two methods of aeration were used: one involved controlling the concentration of oxygen (16–20%) and the other the temperature in the upper part of the reactor (temperature 42–45 °C, oxygen concentration 16– 20%). In terms of moisture content, the highest increase recorded was 0.94% and the highest decrease was 27.54%. The highest decrease in lower calorific value recorded was 9.23% and the highest increase was 41.12%. The energy balance in all the trial runs was positive. We noted that aeration using different concentrations of oxygen is strongly influenced by organic content. Thus, it is suitable only for drying wastes with known and stable compositions. The outcomes of the different methods used were influenced by ambient relative air humidity. Moisture gradients, which are often described in the literature, were not consistently reproduced in this study
The synthesis, chain-packing simulation and long-term gas permeability of highly selective spirobifluorene-based polymers of intrinsic microporosity
Membranes composed of Polymers of Intrinsic Microporosity (SBF-PIMs) have potential for commercial gas separation. Here we report a combined simulation and experimental study to investigate the effect on polymer microporosity and gas permeability by placing simple substituents such as methyl, t-butyl and fused benzo groups onto PIMs derived from spirobifluorene (PIM-SBFs). It is shown that methyl or t-butyl substituents both cause a large increase in gas permeabilities with four methyl groups enhancing the concentration of ultramicropores (1.0 nm). Long-term ageing studies (>3.5 years) demonstrate the potential of PIM-SBFs as high-performance membrane materials for gas separations. In particular, the data for the PIM derived from tetramethyl substituted SBF reaches the proposed 2015 Robeson upper bound for O2/N2 and, hence, hold promise for the oxygen or nitrogen enrichment of air. Mixed gas permeation measurements for CO2/CH4 of the aged PIM-SBFs also demonstrate their potential for natural gas or biogas upgrading
A novel time lag method for the analysis of mixed gas diffusion in polymeric membranes by on-line mass spectrometry: Method development and validation
European Union's Seventh Framework Program (FP7/2007-2013) under Grant agreement no. 608490. project M4CO2. CNR/FCT Italian/Portuguese Bilateral Project 2015-2016 "Advanced studies of the transport properties and gas separation by polymers of intrinsic microporosity (PIMs) and Ionic Liquid Gel Membranes via novel methods" and the CNR-CAS Bilateral Agreement 2016-2018 "Innovative polymeric membranes for pervaporation and advanced gas and vapour separations".A novel method to determine the individual diffusion coefficients of gases in a mixture during their permeation through polymeric membranes is described. The method was developed in two independent laboratories, using rubbery Pebax® and glassy Hyflon® AD60X membrane samples as standards, and validated using the Tröger's base containing Polymer of Intrinsic Microporosity, PIM-EA-TB. Monitoring of the permeate composition in real time by a quadrupole mass spectrometer allowed the analysis of the permeation transient for gas mixtures. Two operation modes, either with a vacuum in the permeate and a direct connection to the mass spectrometer via a heated restriction, or using a sweeping gas and a heated capillary sample inlet, give excellent agreement with the traditional time lag method for single gases. A complete overview of the method development, identification of the critical parameters, instruments calibration, data elaboration and estimation of the experimental accuracy are provided. Validation with PIM-EA-TB, shows that the method can also successfully detect anomalous phenomena, related to pressure and concentration dependency of the transport properties, physical aging or penetrant-induced dilation. Rapid online analysis of the permeate composition makes the method also very suitable for routine mixed gas permeability measurements.publishersversionpublishe
Likely voter model in January 2020
In a survey conducted by Public Opinion Research Centre in January 2020, we investigated how people trust to political Parties and whether they are willing to take part in elections to the Chamber of Deputies. In the press release, there are two different types of information: the likely voter model and the party preferences. The likely voter model indicates the anticipated result of hypothetical elections to the Chamber of Deputies in the time of conducting the survey. The party preferences give us information about public sympathy for political parties in the group of citizens who have voting right and there is also included a part of citizens who will not take part in elections or they do not know who to vote for
Likely voter model in December 2018
In a survey conducted by Public Opinion Research Centre in December 2018, we investigated how people trust to political Parties and whether they are willing to take part in elections to the Chamber of Deputies. In the press release there are two different types of information: the likely voter model and the party preferences. The likely voter model indicates anticipated result of hypothetical elections to the Chamber of Deputies in the time of conducting the survey. The party preferences give us information about public sympathy for political parties in the group of citizens who have voting right and there is also included a part of citizens who will not take part in elections or they do not know who to vote for.s
Voter preferences, decision-making factors and topics of the European Parliament elections in April 2019
In a survey conducted by Public Opinion Research Centre in April 2019, we investigated whether people are willing to take part in elections to the European Parliament, how they trust to political Parties and decision-making voter factors. The voter preferences include only the views of those people who are likely to vote, while people who do not yet know how they will vote have their own category her
Likely voter model in April 2019
In a survey conducted by Public Opinion Research Centre in April 2019, we investigated how people trust to political Parties and whether they are willing to take part in elections to the Chamber of Deputies. In the press release there are two different types of information: the likely voter model and the party preferences. The likely voter model indicates anticipated result of hypothetical elections to the Chamber of Deputies in the time of conducting the survey. The party preferences give us information about public sympathy for political parties in the group of citizens who have voting right and there is also included a part of citizens who will not take part in elections or they do not know who to vote for
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