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Showing papers by "Jožef Stefan Institute published in 2004"


Journal ArticleDOI
TL;DR: This work empirically evaluates several state-of-the-art methods for constructing ensembles of heterogeneous classifiers with stacking and shows that they perform (at best) comparably to selecting the best classifier from the ensemble by cross validation and proposes two extensions of this method using an extended set of meta-level features and multi-response model trees to learn at the meta- level.
Abstract: We empirically evaluate several state-of-the-art methods for constructing ensembles of heterogeneous classifiers with stacking and show that they perform (at best) comparably to selecting the best classifier from the ensemble by cross validation. Among state-of-the-art stacking methods, stacking with probability distributions and multi-response linear regression performs best. We propose two extensions of this method, one using an extended set of meta-level features and the other using multi-response model trees to learn at the meta-level. We show that the latter extension performs better than existing stacking approaches and better than selecting the best classifier by cross validation.

768 citations


Journal ArticleDOI
TL;DR: It is shown that selective lysosome disruption with l-leucyl-l-leucine methyl ester results in apoptosis, characterized by translocation of lysOSomal proteases into the cytosol and by the cleavage of a proapoptotic Bcl-2-family member Bid.

458 citations


Proceedings ArticleDOI
16 Sep 2004
TL;DR: It is illustrated possible application of Gaussian process models within model-based predictive control, where optimization of control signal takes the variance information into account, on control of pH process benchmark.
Abstract: Gaussian process models provide a probabilistic non-parametric modelling approach for black-box identification of non-linear dynamic systems. The Gaussian processes can highlight areas of the input space where prediction quality is poor, due to the lack of data or its complexity, by indicating the higher variance around the predicted mean. Gaussian process models contain noticeably less coefficients to be optimized. This paper illustrates possible application of Gaussian process models within model-based predictive control. The extra information provided within Gaussian process model is used in predictive control, where optimization of control signal takes the variance information into account. The predictive control principle is demonstrated on control of pH process benchmark.

284 citations


Journal ArticleDOI
TL;DR: In this article, the minimal renormalizable supersymmetric SO(10) GUT with the usual three generations of spinors has a Higgs sector consisting only of a light 10 dimensional and heavy 126, 126 and 210 supermultiplets.

224 citations


Journal ArticleDOI
TL;DR: In this paper, experimental and numerical analysis were performed to evaluate heat transfer characteristics of water flowing through triangular silicon micro-channels with hydraulic diameter of 160 lm in the range of Reynolds number Re ¼ 3:2-64.

218 citations


Journal ArticleDOI
TL;DR: In this paper, the properties of composites with nanoparticles, the key material parameters, and the characteristics of a single-layer absorber made from a nanoparticle composite were examined theoretically.
Abstract: Composites with nanosize ferromagnetic particles can be useful in microwave absorbers, since nanoparticles exhibit distinct magnetic properties compared to bulk materials. This paper examines theoretically the properties of composites with nanoparticles, the key material parameters, and the characteristics of a single-layer absorber made from a nanoparticle composite. In such an absorber, high magnetic losses over a wide frequency range induce a series of strong and wide absorption peaks at increasing frequencies. By using metallic (iron and cobalt) nanoparticles, absorbers with relatively low volume fraction of metallic inclusions can be made. The paper compares the characteristics of nanocomposite absorbers to those of common dielectric or ferromagnetic absorbers and identifies the potential advantages of nanocomposite absorbers. Because nanocomposite absorbers combine advantages of both dielectric and ferromagnetic absorbers and have significantly better characteristics, they could become essential for production of microwave and millimeter-wave absorbers.

216 citations


Proceedings ArticleDOI
25 Jul 2004
TL;DR: Experiments show that feature selection using weights from linear SVMs yields better classification performance than other feature weighting methods when combined with the three explored learning algorithms.
Abstract: This paper explores feature scoring and selection based on weights from linear classification models. It investigates how these methods combine with various learning models. Our comparative analysis includes three learning algorithms: Naive Bayes, Perceptron, and Support Vector Machines (SVM) in combination with three feature weighting methods: Odds Ratio, Information Gain, and weights from linear models, the linear SVM and Perceptron. Experiments show that feature selection using weights from linear SVMs yields better classification performance than other feature weighting methods when combined with the three explored learning algorithms. The results support the conjecture that it is the sophistication of the feature weighting method rather than its apparent compatibility with the learning algorithm that improves classification performance.

207 citations


Journal ArticleDOI
TL;DR: In this article, the existence of a tie line between silver electrodes and low-firing ceramics has been investigated in terms of the presence of the tie line in the corresponding ternary phase diagram, and the probability of such tie line is related to the conditions in subordinated silver-based isothermal binary systems.
Abstract: The chemical compatibility of silver electrodes and low-firing ceramics has been considered, in terms of the existence of a tie line between silver (and/or Ag2O) and the binary oxide compound in the corresponding ternary phase diagram. The probability of the existence of the tie line is related to the conditions in the subordinated silver-based isothermal binary systems. Greater probabilities have been calculated for the systems with fewer silver-based binary compounds. Based on the concepts that have been developed, several silver-based isothermal binary systems have been investigated to identify the oxides suitable for the development of low-temperature cofired ceramics. The developed concept has been tested by investigating the phase relations in the Bi2O3–Nb2O5 and Bi2O3–V2O5 ternary systems with silver. X-ray and microstructural investigations of bismuth niobates and bismuth vanadates reveal that, as a result of the inertness of Bi2O3 and the reactivity of Nb2O5 and V2O5 toward silver, compounds that are rich in niobium or vanadium react with silver to form ternary Nb/V-Bi-Ag oxide compounds, whereas for compounds that are rich in bismuth, tie lines to silver and Ag2O do exist.

188 citations


Journal ArticleDOI
TL;DR: This paper exploits the similarity between human motion and humanoid robot motion to generate joint trajectories for humanoids and proposes an automatic approach to relate humanoid robot kinematics parameters to the kinematic parameters of a human performer.

179 citations


Journal ArticleDOI
TL;DR: In this paper, a lead-free relaxor has been produced from the K0.5Na 0.5NbO3-SrTiO3 (KNN-STO) system.
Abstract: New lead-free relaxors have been produced from the K0.5Na0.5NbO3–SrTiO3 (KNN-STO) system. The solid solubility within the studied range of compositions (1 -x) K0.5Na0.5NbO3–xSrTiO3 was observed for x up to 0.33. A pseudo-cubic perovskite structure was determined for x = 0.15 to 0.25. The high density and the uniform distribution of fine grains and pores were confirmed by the translucency of these ceramics. The 0.85KNN-0.15STO composition reaches the dielectric permittivity of above 3000 at room temperature. Dielectric spectroscopy measurements revealed that, as with lead-based complex perovskites, the cationic distribution disorder is reflected in relaxorlike properties, thus suggesting possible applications based on this environmentally friendly lead-free ceramic system.

166 citations


Journal ArticleDOI
TL;DR: It is shown that a broad-spectrum cysteine cathepsin inhibitor effectively blocks several stages of tumorigenesis in the RIP1-Tag2 transgenic mouse model, offering new therapeutic opportunities in cancer treatment.

Journal ArticleDOI
TL;DR: In this paper, the complete mass matrices of the SU(2)$ doublets and the color triplets are computed in connection with the doublet-triplet splitting and the $d=5$ proton decay.
Abstract: We discuss in detail the symmetry breaking and related issues in the minimal renormalizable supersymmetric grand unified theory. We find all the possible patterns of symmetry breaking, compute the associated particle spectrum and study its impact on the physical scales of the theory. In particular, the complete mass matrices of the $\mathrm{SU}(2)$ doublets and the color triplets are computed in connection with the doublet-triplet splitting and the $d=5$ proton decay. We explicitly construct the two light Higgs doublets as a function of the Higgs superpotential parameters. This provides a framework for the analysis of phenomenological implications of the theory, to be carried out in a second paper.

Journal ArticleDOI
TL;DR: In this article, a multidimensional modeling of vertical upward subcooled boiling flow using a two-fluid approach and calculation of local two-phase flow parameters (void fraction and bubble size) was taken into account.

Journal ArticleDOI
TL;DR: In this article, the solid solubility of R ions (R = Ho3+, Dy3+, and Y3+) in the BaTiO3 perovskite structure was studied by quantitative electron-probe microanalysis (EPMA) using wavelength-dispersive spectroscopy (WDS), scanning electron microscopy (SEM), and X-ray diffractometry (XRD).
Abstract: The solid solubility of R ions (R = Ho3+, Dy3+, and Y3+) in the BaTiO3 perovskite structure was studied by quantitative electron-probe microanalysis (EPMA) using wavelength-dispersive spectroscopy (WDS), scanning electron microscopy (SEM), and X-ray diffractometry (XRD). Highly doped BaTiO3 samples were prepared using mixed-oxide technology including equilibration at 1400° and 1500°C in ambient air. The solubility was found to depend mainly on the starting composition. In the TiO2-rich samples a relatively low concentration of R incorporated preferentially at the Ba2+ lattice sites (solubility limit ∼Ba0.986R0.014Ti0.9965(V″Ti″)0.0035O3at 1400°C). In BaO-rich samples a high concentration of R entered the BaTiO3 structure at the Ti4+ lattice sites (solubility limit ∼BaTi0.85R0.15O2.925(VO••)0.075at 1500°C). Ho3+, Dy3+, and Y3+incorporated preferentially at the Ti4+ lattice sites stabilize the hexagonal polymorph of BaTiO3. The phase equilibria of the Ho3+–BaTiO3 solid solutions were presented in a BaO–Ho2O3–TiO2phase diagram.

Journal ArticleDOI
TL;DR: It was shown that some extraction steps, such as the organo-chelating Hg fraction, do not provide meaningful results, which suggests that protocols for mercury fractionation need further harmonization in order to improve the comparability of the results and their use in risk assessment.
Abstract: Mercury (Hg) fractionation was investigated in contaminated soil in the Idrija Hg-mine region, Slovenia. The main aim of this study was to test and apply sequential extraction and quantification of different Hg phases in order to estimate the mobility and potential bioavailability of Hg in contaminated soils. Separation of Hg phases was performed by means of a selective sequential extraction procedure complemented by volatilization of elemental mercury (Hg0). The influence of temperature, moisture and storage on Hg0 volatilization was also investigated. The total Hg concentrations varied between 8.4 and 415 mg kg−1 and were up to 40-fold higher than the maximum permissible set by Slovenian legislation. Fractionation measurements indicated cinnabar as the predominant Hg fraction, followed by Hg0. Accumulation of cinnabar predominantly occurred in coarse grained flood plain sediments, where on average it constituted more than 80% of total Hg. In contrast non-cinnabar fractions were found to be enriched in areas where fine grained material was deposited, reaching up to 60% of total Hg. The strong positive correlation (R2 = 0.71–0.99) among non-cinnabar fractions suggested that these fractions predominantly control the mobility and potential bioavailability of Hg. Sample pretreatment before fractionation influenced the partition of Hg between different fractions, and therefore fractionation in fresh, nontreated samples is suggested. In addition, the specificity of the extraction steps needs further attention, as it was shown that some extraction steps, such as the organo-chelating Hg fraction, do not provide meaningful results. This further suggests that protocols for mercury fractionation need further harmonization in order to improve the comparability of the results and their use in risk assessment. Volatile mercury fluxes averaged between 0.04 and 6.5 ng g−1 h−1. Good agreement (R2 = 0.81–0.95) was found between the non-cinnabar fractions and evaporation of Hg0. Both the temperature and sample moisture had significant effects on mercury volatilization. The results in this study were obtained at 70 °C, which may be somewhat high, in particular for bacterial activity which may also play an important role in Hg volatilization. Therefore it is strongly suggested that further optimisation of the protocol to assess Hg volatilization from soil is required.

Journal ArticleDOI
TL;DR: The content of Co-, Ni- and Mo-oxide in the passive layer is lower in the presence of EDTA, thus indicating increased solubility associated with higher stability constants for complexes of metal cations with EDTA.
Abstract: The composition of the passive layers formed by electrochemical oxidation at different passivation potentials on Co–Cr–Mo and Co–Ni–Cr–Mo alloys in simulated physiological solution (SPS), with and without the complexing agent EDTA, was studied by X-ray photoelectron spectroscopy. Composition as a function of depth, cationic fraction and thickness of the passive film was determined. Chromium oxide is shown to be the major constituent of the passive layer on both Co–Cr–Mo and Co–Ni–Cr–Mo alloys. The minor constituents of the passive layers, Co- and Mo-oxide in the case of Co–Cr–Mo alloy and Ni-, Co- and Mo-oxides in the case of Co–Ni–Cr–Mo alloy, are also located in the outer part of the layer. EDTA affects the formation of the passive layer on each alloy. The content of Co-, Ni- and Mo-oxide in the passive layer is lower in the presence of EDTA, thus indicating increased solubility associated with higher stability constants for complexes of metal cations with EDTA.

Journal ArticleDOI
TL;DR: In this article, the properties of a new air-stable nanowire material with the chemical formula Mo6S3I6 were reported, and the distinguishing features of the material are rapid one-step synthesis, easy isolation and controllable dispersion into small-diameter wire bundles.
Abstract: We report on the properties of a new air-stable nanowire material with the chemical formula Mo6S3I6 .T he distinguishing features of the material are rapid one-step synthesis, easy isolation and controllable dispersion into small-diameter wire bundles. Elemental analysis, x-ray diffraction, thermogravimetry, differential thermal analysis, Raman scattering and electron microscopy were used to characterize the material.

Journal ArticleDOI
TL;DR: In this article, solid-state synthesis of compositions from the Bi2O3-TeO2 system showed that, under an oxygen atmosphere, Te4+ oxidizes to Te6+ and yields four room-temperature stable compounds: Bi2Te2O8, BiTeO6, Bi6Te2 O15, and new compound with the nominal composition 7Bi2Te3·2TeOO2.
Abstract: Solid-state synthesis of compositions from the Bi2O3–TeO2 system show that, under an oxygen atmosphere, Te4+ oxidizes to Te6+ and yields four room-temperature stable compounds: Bi2Te2O8, Bi2TeO6, Bi6Te2O15, and new a compound with the nominal composition 7Bi2O3·2TeO2. Dense ceramics can be prepared from all these compounds by sintering between 650° and 800°C under an oxygen atmosphere. The permittivity of these compounds varies from ∼30 to ∼54, the Q×f value from 1.100 to 41.000 GHz (∼5 GHz), and the temperature coefficient of resonant frequency from −43 to −144 ppm/K. Bi6Te2O15 and 7Bi2O3·2TeO2 do not react with silver, and, therefore, they have the potential to be used for applications in low-temperature cofired ceramic (LTCC) technology.

Journal ArticleDOI
TL;DR: The diversity, origin, and evolution of chromoviruses in Eukaryota were examined using the massive amount of genome sequence data for different eukaryotic lineages and a surprisingly large number of novel full-length chromoviral elements were found.
Abstract: The diversity, origin, and evolution of chromoviruses in Eukaryota were examined using the massive amount of genome sequence data for different eukaryotic lineages. A surprisingly large number of novel full-length chromoviral elements were found, greatly exceeding the number of the known chromoviruses. These new elements are mostly structurally intact and highly conserved. Chromoviruses in the key Amniota lineage, the reptiles, have been analyzed by PCR to explain their evolutionary dynamics in amniotes. Phylogenetic analyses provide evidence for a novel centromere-specific chromoviral clade that is widespread and highly conserved in all seed plants. Chromoviral diversity in plants, fungi, and vertebrates, as shown by phylogenetic analyses, was found to be much greater than previously expected. The age of plant chromoviruses has been significantly extended by finding their representatives in the most basal plant lineages, the green and the red algae. The evolutionary origin of chromoviruses has been found to be no earlier than in Cercozoa. The evolutionary history and dynamics of chromoviruses can be explained simply by strict vertical transmission in plants, followed by more complex evolution in fungi and in Metazoa. The currently available data clearly show that chromoviruses indeed represent the oldest and the most widespread clade of Metaviridae.

Journal ArticleDOI
TL;DR: In this article, the Girshberg-Yacoby off-center cation model of perovskite ferroelectrics was applied to the Langevin equations of motion and the soft-spin formalism for the pseudospin degrees of freedom with 1u symmetry.
Abstract: It has recently been shown by NMR techniques that in the high-temperature cubic phase of ${\mathrm{BaTiO}}_{3}$ the $\mathrm{Ti}$ ions are not confined to the high-symmetry cubic sites, but rather occupy one of the eight off-center positions along the $[111]$ directions. The off-center $\mathrm{Ti}$ picture is in apparent contrast with most soft-mode-type theoretical descriptions of this classical perovskite ferroelectric. Here we apply the Girshberg-Yacoby off-center cation model of perovskite ferroelectrics assuming that the symmetrized occupation operators or ``pseudospins'' for the $\mathrm{Ti}$ off-center sites are linearly coupled to the normal coordinates for $\mathrm{TO}$ lattice vibrations. In the adiabatic limit, the coupling is eliminated by transforming to displaced phonon coordinates, and after excluding the self-interaction terms an effective $\mathrm{Ti}\text{\ensuremath{-}}\mathrm{Ti}$ interaction is obtained. Using the Langevin equations of motion and the soft-spin formalism for the $\mathrm{Ti}$ pseudospin degrees of freedom with ${T}_{1u}$ symmetry, the dynamic response of the coupled system is derived. The results are shown to be in qualitative agreement with the experimental data of Vogt et al. [Phys. Rev. B, 26, 5904 (1982)] obtained by hyper-Raman scattering. The nature of the phase transition, which is of a mixed displacive and order-disorder type, is discussed.

Journal ArticleDOI
01 Feb 2004-Methods
TL;DR: This review summarizes approaches to generate active papain-like cysteine proteases by heterologous expression by evaluating structure-activity relationships, 3-D structures as well as to screen for and optimize potent and selective inhibitors.


Journal ArticleDOI
TL;DR: Under conditions of severe water deficit, the most sensitive cultivar exhibited a marked increase in the activity of two different aminopeptidases, while the more resistant cultivar showed a significant decrease in theactivity of these aminopes, pointing to complex and probably specific roles in the plant response to drought.

Journal ArticleDOI
TL;DR: In this article, a basic characterization of several low-temperature-sintered calcium silicates, germanates and tellurates was performed to evaluate their potential as glass-free low-permittivity substrate LTCC materials.
Abstract: To reduce the complexity of LTCC systems, and so accelerate the development of LTCC tapes with new functionalities, it is necessary to reduce the number of phases within a particular tape. This can best be done by using glass-free single-phase ceramic systems. We performed a basic characterization of several low-temperature-sintered calcium silicates, germanates and tellurates in order to evaluate their potential as glass-free low-permittivity substrate LTCC materials. Special attention was focused on their microwave and 1 MHz dielectric properties, their sintering behavior and their compatibility with Ag. Two Ca-germanates, which were found to be the most interesting for LTCC applications exhibit a permittivity of ∼10 and low dielectric losses; however, the temperature dependence of permittivity and the sintering temperature must be further reduced. For CaGeO3 the temperature dependence of permittivity was fully suppressed by the addition of 10 mol% of CaTiO3.

Journal ArticleDOI
TL;DR: Involvement of the VuC1 cDNA in the cellular response to various abiotic stresses was studied, using Northern blot and Western blot analysis, in the leaf tissues of cowpea plants corresponding to two cultivars with different capacity to tolerate drought‐stress.

Journal ArticleDOI
TL;DR: It is demonstrated that PLS is genetically homogeneous and the mutation spectrum that includes three novel mutations in 21 PLS families provides an insight into structure–function relationships of CTSC, suggesting that prepubertal periodontitis is a genetically heterogeneous disease that, in some families, just represents a partially penetrant PLS.
Abstract: We have previously reported that loss-of-function mutations in the cathepsin C gene (CTSC) result in Papillon Lefevre syndrome, an autosomal recessive condition characterized by palmoplantar keratosis and early,onset, severe periodontitis. Others have also reported CTSC mutations in patients with severe prepubertal periodontitis, but without any skin manifestations. The possible role of CTSC variants in more common types of non-mendelian, early-onset, severe periodontitis ("aggressive periodontitis") has not been investigated. In this study, we have investigated the role of CTSC in all three conditions. We demonstrate that PLS is genetically homogeneous and the mutation spectrum that includes three novel mutations (c.386T>A/p. V129E, c.935A>G/p.Q312R, and c.1235A>G/p.Y412C) in 21 PLS families (including eight from our previous study) provides an insight into structure-function relationships of CTSC. Our data also suggest that a complete loss-of-function appears to be necessary for the manifestation of the phenotype, making it unlikely that weak CTSC mutations are a cause of aggressive periodontitis. This was confirmed by analyses of the CTSC activity in 30 subjects with aggressive periodontitis and age-sex matched controls, which demonstrated that there was no significant difference between these two groups (1,728.7 +/- SD 576.8 mu moles/mg/min vs. 1,678.7 +/- SD 527.2 mu moles/mg/min, respectively, p = 0.73). CTSC mutations were detected in only one of two families with prepubertal periodontitis; these did not form a separate functional class with respect to those observed in classical PLS. The affected individuals in the other prepubertal periodontitis family not only lacked CTSC mutations, but in addition did not share the haplotypes at the CTSC locus. These data suggest that prepubertal periodontitis is a genetically heterogeneous disease that, in some families, just represents a partially penetrant PLS. (C) 2004 Wiley-Liss, Inc.

Journal ArticleDOI
TL;DR: In this article, a planetary ball mill was used to transform carbonated fluorhydroxyapatite (FA) powders into a single phase of FA after 9h of milling and thermally treating, and various experimental techniques like X-ray Diffraction (XRD), Differential Thermal Analysis (DTA), Infrared Spectroscopy (IR), Transmission Electron Microscopy and Scanning Electron microscopy (SEM).

Journal ArticleDOI
TL;DR: It is shown that, contrary to intuition, small (< or =1 microm) transparent particles can be trapped and manipulated in a nematic liquid crystal using an intense laser beam, although their index of refraction is lower than both refractive indices of the surrounding birefringent fluid.
Abstract: We show that, contrary to intuition, small (< or =1 microm) transparent particles can be trapped and manipulated in a nematic liquid crystal using an intense laser beam, although their index of refraction is lower than both refractive indices of the surrounding birefringent fluid. Two mechanisms are identified that are responsible for this anomalous trapping: (i) surface-induced distortion of the birefringent media around the particle, creating a high-index "cloud" around the colloid, and (ii) laser-induced distortion or (partial) melting of a nematic, creating a ghost colloid.

Journal ArticleDOI
TL;DR: In this article, a room-temperature ionic liquid, 1-ethyl-3-methylimidazolium fluorohydrogenate (EMIm(HF)2.3F, EMIm = 1-methyl-3methyloridazolate cation), and Lewis fluoroacids (BF3, PF5, Asf5, NbF5, TaF5 and WF6) gave EMIm salts of the corresponding fluorocomplex anions, including EMImBF4, EMIMPF6, EMAsF6
Abstract: Fluoroacid–base reactions of a room-temperature ionic liquid, 1-ethyl-3-methylimidazolium fluorohydrogenate (EMIm(HF)2.3F, EMIm = 1-ethyl-3-methylimidazolium cation), and Lewis fluoroacids (BF3, PF5, AsF5, NbF5, TaF5 and WF6) give EMIm salts of the corresponding fluorocomplex anions, EMImBF4, EMImPF6, EMImAsF6, EMImNbF6, EMImTaF6 and EMImWF7, respectively. Attempts to prepare EMImVF6 by both the acid–base reaction of EMIm(HF)2.3F with VF5 and the metathesis of EMImCl with KVF6 failed due to the strong oxidizing power of the pentavalent vanadium, whereas EMImSbF6 was successfully prepared only by the metathesis of EMImCl and KSbF6. EMImBF4, EMImSbF6, EMImNbF6, EMImTaF6 and EMImWF7 are liquids at room temperature whereas EMImPF6 and EMImAsF6 melts at around 330 K. Raman spectra of the obtained salts showed the existence of the EMIm cation and corresponding fluorocomplex anions. IR spectroscopy revealed that strong hydrogen bonds are not observed in these salts. EMImAsF6 (mp 326 K) and EMImSbF6 (mp 283 K) are isostructural with the previously reported EMImPF6. The melting point of the hexafluorocomplex EMIm salt decreases with the increase of the size of the anion (PF6− < AsF6− < SbF6−

Journal ArticleDOI
TL;DR: In this paper, the authors measured at radio frequencies at 2 GHz and AgNb1−xTaxO3 (0.46 410) and reported low dissipation factors (tgδ= 7 ×10−4−18 × 10−4), low aging rate, and good dielectric strength.
Abstract: Ceramic samples with the AgNb1−xTaxO3 (0.46 410, whereas the Q×f value, measured at 2 GHz, reaches values of 640–900 GHz. Dependence of the resonant frequency on temperature was not linear but did display a minimum at a particular temperature, which was dependent on the composition of the ceramic. Samples that were measured at radio frequencies displayed low dissipation factors (tgδ= 7 ×10−4−18 × 10−4), a low aging rate (0.2% per time decade), and good dielectric strength (8 V/μm at a thickness of 0.6 mm). Microstructural investigations revealed the presence of precipitates and transformation twins that should be eliminated during additional processing optimization.