Search Results
Abstract
The synthesis of new compounds based on Bi2O3 is investigated because they can be used as new environmentally friendly inorganic pigments. Chemical compounds of the (Bi2O3)1–x(Er2O3)x type were synthetized. The host lattice of these pigments is Bi2O3 that is doped by Er3+ ions. The incorporation of doped ions provides interesting colours and contributes to an increase in the thermal stability of these compounds. The simultaneous TG-DTA measurements were used for determination of the temperature region of the pigment formation and thermal stability of pigments.
Abstract
The synthesis of new compounds based on Bi2O3 is investigated because they can be used as new ecological inorganic pigments. Chemical compounds of the (Bi2O3)1−x(Y2O3)x type were synthesized. The host lattice of these pigments is Bi2O3 that is doped by Y3+ ions. The incorporation of doped ions provides the interesting colours and contributes to a growth of the thermal stability of these compounds. The simultaneous TG-DTA measurements were used for determination of the temperature region of the pigment formation and thermal stability of pigments. This paper also contains the results of the pigment characterization by X-ray powder diffraction and their colour properties.
Abstract
New inorganic compounds having the general formula (Bi2O3)1−x (Lu2O3) x (x ranges from 0.1 to 0.5) displaying orange colours have been synthesized by traditional solid-state route, as viable alternatives to lead, cadmium and chromium based yellow toxic inorganic pigments. The host lattice of these pigments is Bi2O3 that is doped by Lu3+ ions. The goal was to develop conditions for the synthesis of these compounds and to determine the influence of calcination temperature and lutetium content on their colouring effects. The simultaneous TG-DTA measurements were used for determination of the temperature region of the pigment formation and thermal stability of pigments. The pigments were also evaluated from the standpoint of their structure and particle sizes.
Abstract
The study of the system xSb2O3–(1 − x)Bi2O3–6(NH4)2HPO4 has been carried out to identify the phases and simulate the mechanisms of their formation, using the technique of thermal analysis in association with X-ray diffractometry. The main stages observed during thermal treatment of the samples include: (1) elimination of water and ammonia leading to the formation of (NH4)5P3O10; (2) reaction of the latter with M2 IIIO3 and the formation of acidic polyphosphates M2 IIIH2P3O10; (3) their dehydration with the formation of the polyphosphates MIII(PO3)3. Then Sb(PO3)3 decomposes giving SbPO4 and P2O5. In the presence of excessive P2O5, two moles of Bi(PO3)3 condensate into oxophosphates Bi2P4O13 and BiP5O14. The data of thermal analysis match with the composition of intermediate and final products. The hygroscopicity of the samples diminishes with growing bismuth content.
Abstract
The synthesis of new compounds based on the Bi2O3–Ho2O3 system, which can be used as new ecological inorganic pigments, is investigated in our laboratory. The optimum conditions for the syntheses of these compounds have been followed by the methods of thermal analysis that can provide first information about the temperature region of the pigment formation. The synthesis of these compounds was followed by thermal analysis using STA 449/C Jupiter (Netzsch, Germany).
This paper reviews the issue of population size (scale effects) in idea-based growth models. It addresses both weak and strong scale effects and incorporates the related distinctive features of the three strata of idea-based growth models. The paper also comments on third-generation models, emphasising their fragile framework due to the limited range of R&D spillover space they can accommodate. It is argued that because of the shortcomings of the third-generation models, a precise mapping of the relationship between population size and economic growth requires further research.
Abstract
Data on patent families is used in economic and statistical studies for many purposes, including the analysis of patenting strategies of applicants, the monitoring of the globalization of inventions and the comparison of the inventive performance and stock of technological knowledge of different countries. Most of these studies take family data as given, as a sort of black box, without going into the details of their underlying methodologies and patent linkages. However, different definitions of patent families may lead to different results. One of the purposes of this paper is to compare the most commonly used definitions of patent families and identify factors causing differences in family outcomes. Another objective is to shed light into the internal structure of patent families and see how it affects patent family outcomes based on different definitions. An automated characterization of the internal structures of all extended families with earliest priorities in the 1990s, as recorded in PATSTAT, found that family counts are not affected by the choice of patent family definitions in 75% of families. However, different definitions may really matter for the 25% of families with complex structures and lead to different family compositions, which might have an impact, for instance, on econometric studies using family size as a proxy of patent value.
Abstract
Hungarian small- and medium-sized enterprises are facing the challenges of digitalisation and innovation to survive fierce competition in the era of Industry 4.0, and particularly of COVID-19. Survival in the heavily hit sectors depends on the degree of digitalisation and involvement in e-commerce. This paper aims to examine Hungarian SMEs’ current scale of digitalisation and adoption of Industry 4.0 technologies. It also analyses the role of the Hungarian government’s support for SMEs’ digital transformation. To this end, secondary data were collected from Eurostat, the European Commission and the Hungarian Central Statistical Office, including the Digital Economy and Society Index (DESI), indices of skills and innovation from SME performance reviews and sectoral business statistics. In processing the data, the study strictly followed the European Commission’ classification protocol, complemented by a qualitative analysis of reports and programmes related to digitalisation and Industry 4.0 in Hungary. The findings reveal that there is a further need for strengthening the digitalisation and innovation capacities of Hungarian SMEs. The effects of introduced measures could not be seen yet. Hence, the Hungarian government should continue to support SMEs’ digital transformation in order to increase their role in high-tech manufacturing and knowledge-intensive services.
The role of spatial proximity to innovation inputs (such as industrial R&D or academic research) in technological change has been widely studied in the economics literature. However, most of the papers in this research area are based on data for technologically advanced countries such as the US and parts of the EU. During transition recently accessed countries of Central Europe have undergone a dramatic restructuring process that significantly affected their systems of innovation: R&D expenditures, academic research and patenting activity have declined. According to some research results FDI constituted the most significant drive of technological change during the 1990s. Is there any role of spatially mediated knowledge spillovers in innovation in these countries? To what extent regional systems of innovation have started to develop in Central European new EU member countries? These questions have rarely been raised in the relevant literature. Using regional data this paper adopts econometric modelling techniques commonly applied in innovation research to study the role of localised knowledge inputs in technological change in Hungary.
We test the Global Engagement (GE) hypothesis according to which the most globally engaged firms, whether multinationals or exporters, are the most innovative. The test is applied to data from 4815 Portuguese firms for the period 2002–2004 based on the 4th Community Innovation Survey for Portugal. We estimated several Knowledge Production Functions, assuming that knowledge outputs result from the combination of certain knowledge inputs with the flow of ideas coming from the existing stock of knowledge. We found that the more internationally engaged firms create more knowledge output than their domestic counterparts; indeed, the more globalised firms apply more inputs and have the opportunity to use a larger stock of knowledge. Nevertheless, the relative perceived advantage of the more internationally exposed firms is also the result of their globalised nature, and is not directly connected with knowledge inputs or information flows.
