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Structural changes in the brain take place throughout one’s life. Changes related to cognitive decline may delay the stages of the speech production process in the aging brain. For example, semantic memory decline and poor inhibition may delay the retrieval of a concept from the mental lexicon. Electroencephalography (EEG) is a valuable method for identifying the timing of speech production stages. So far, studies using EEG mainly focused on a particular speech production stage in a particular group of subjects. Differences between subject groups and between methodologies have complicated identifying time windows of the speech production stages. For the current study, the speech production stages lemma retrieval, lexeme retrieval, phonological encoding, and phonetic encoding were tracked using a 64-channel EEG in 20 younger adults and 20 older adults. Picture-naming tasks were used to identify lemma retrieval, using semantic interference through previously named pictures from the same semantic category, and lexeme retrieval, using words with varying age of acquisition. Non-word reading was used to target phonological encoding (using non-words with a variable number of phonemes) and phonetic encoding (using non-words that differed in spoken syllable frequency). Stimulus-locked and response-locked cluster-based permutation analyses were used to identify the timing of these stages in the full time course of speech production from stimulus presentation until 100 ms before response onset in both subject groups. It was found that the timing of each speech production stage could be identified. Even though older adults showed longer response times for every task, only the timing of the lexeme retrieval stage was later for the older adults compared to the younger adults, while no such delay was found for the timing of the other stages. The results of a second cluster-based permutation analysis indicated that clusters that were observed in the timing of the stages for one

Benevolent and corrective humor are two comic styles that have been related to virtue, morality, and character strengths. A previous study also supported the viability of measuring these two styles with the BenCor in 22 countries. The present study extends the previous one by including further countries (a total of 25 countries in 29 samples with N = 7813), by testing the revised BenCor (BenCor-R), and by adding two criterion measures to assess life satisfaction and four broad humor dimensions (social fun/entertaining humor, mockery, humor ineptness, and cognitive/reflective humor). As expected, the BenCor-R showed mostly promising psychometric properties (internal consistency and factorial validity). Consistent with previous studies, benevolent humor correlated positively with life satisfaction in most countries, while corrective humor was uncorrelated with life satisfaction. These relationships were only slightly changed when controlling for social fun/entertaining humor and mockery, respectively. Benevolent humor was mostly positively associated with cognitive/reflective humor, followed by social fun/entertaining humor and mockery. Corrective humor was mostly positively associated with mockery, followed by cognitive/reflective and social fun/entertaining humor, although these relationships differed between the countries. Overall, the present study supports the viability of benevolent and corrective humor, which has yet received insufficient attention in psychology, for cross-cultural investigations and applications of humor, well-being, and morality.

Recently, two forms of virtue-related humor, benevolent and corrective, have been introduced. Benevolent humor treats human weaknesses and wrongdoings benevolently, while corrective humor aims at correcting and bettering them. Twelve marker items for benevolent and corrective humor (the BenCor) were developed, and it was demonstrated that they fill the gap between humor as temperament and virtue. The present study investigates responses to the BenCor from 25 samples in 22 countries (overall= 7,226). The psychometric properties of the BenCor were found to be sufficient in most of the samples, including internal consistency, unidimensionality, and factorial validity. Importantly, benevolent and corrective humor were clearly established as two positively related, yet distinct dimensions of virtue-related humor. Metric measurement invariance was supported across the 25 samples, and scalar invariance was supported across six age groups (from 18 to 50+ years) and across gender. Comparisons of samples within and between four countries (Malaysia, Switzerland, Turkey, and the UK) showed that the item profiles were more similar within than between countries, though some evidence for regional differences was also found. This study thus supported, for the first time, the suitability of the 12 marker items of benevolent and corrective humor in different countries, enabling a cumulative cross-cultural research and eventually applications of humor aiming at the good.

High-temperature superconducting thin films (YBa2Cu3O7−x) are emerging in superconducting single photon detector (SSPD) research as a novel replacement for conventional and semiconductor detectors. The major hindrance for this is the degradation of the superconducting properties of YBa2Cu3O7−x (YBCO) thin film with reduction of its lateral and longitudinal dimensions (i.e., film thickness and width of the stripe). Furthermore, the surface of the film should be smooth to enable fabrication of the SSPD device. In order to improve the quality of YBCO thin films, we exploited various buffer layers (i.e., SrTiO3, CeO2, and PrBa2 Cu3O7) with thickness of 30 ± 5 nm. We have also investigated the properties of (65 ± 5-nm-thick) YBCO films grown simultaneously on different substrates (i.e., SrTiO3, LaAlO3, MgO, and yttrium stabilized zirconia). For some substrate/buffer material combinations, the surface morphology of the YBCO film has been effectively improved. Also, there was only a small or no degradation of their critical temperature values. These structures give a precursor for further development of fabrication technology for YBCO-based SSPD devices.

We have investigated superlattices consisting of up to 30 epitaxial nanomultilayers (3-7 nm thick) of ferromagnetic La2/3Ca 1/3MnO3 (LCMO) and insulating SrTiO3 (STO) hybrids. The superlattices demonstrate dramatic shifts of Curie temperature, indicating the possibility of its tunability. The metal-insulator transition (MIT) has been observed around 140 K. Below the MIT temperature, the superlattices have shown sharp drops of resistivity, facilitating the largest and sharpest magnetoresistance peaks (>2000%) ever observed in LCMO films and superlattices at low temperatures. The observed experimental results can be explained in the frame of the phase separation model in manganites with well-organized structures. The results of magnetic and transport measurements of such hybrid structures are discussed, indicating a magnetodielectric effect in STO interlayers. The magnetic and transport properties of the superlattices are shown to be technology-dependent, experiencing dimensional transitions, which enables the creation of structures with prescribed magnetoresistance characteristics for a broad range of applications.

We are developing two-layered Yttrium Barium Copper Oxide (YBCO) thin film structures for energy efficient data links for superconducting electronics and present the results of their property measurements. High temperature superconductors (HTS) are advantageous for the implementation of energy-efficient cables interconnecting low temperature superconductor-based circuits and other cryogenic electronics circuits at higher temperature stages. The advantages of the HTS cables come from their low loss and low dispersion properties, allowing ballistic transfer of low power signals with very high bandwidth, low heat conduction and negligible inter-line crosstalk. The microstrip line cable geometry for typical materials is a two-layered film, in which the two superconducting layers are separated by an insulation layer with a minimized permittivity. We have made a proof of concept design of two YBCO films grown by pulsed laser deposition and then assembled into a sandwich with uniform insulating interlayer of tens of micrometers thick. We report on results obtained from such systems assembled in different ways. Structural and electromagnetic properties have been examined on individual films and on the corresponding sandwich composite.

We investigated superconducting YBa2Cu3O7 (YBCO), insulator SrTiO3 (STO), and ferromagnetic La2/3Ca1/3MnO3 (LCMO) multilayered heterostructures grown by pulsed laser deposition (PLD) on h100i YSZ substrates. These hybrid structures have demonstrated strong superconducting properties, similar to those of YBCO films, with a minimum influence of the ferromagnetic layer. We report unusual transport properties and negative differential resistance above the superconducting transition. The electro- and magnetoresistance effects observed in a hybrid YBCO micro-bridge with a top LCMO layer may be the consequence of phase separation induced by electric current.

A pinning potential for vortices was introduced assuming plastic pinning of vortex lattice on chains of out-of-plane individual edge dislocations that form low-angle domain boundaries in high quality YBa2Cu3O7 thin films. Using this pinning potential with the classical Kim–Anderson vortex creep approach a model for critical current dependence on field has been successfully developed. The model shows a plausible description of Jc(Ba) over the entire field range. Electrical field criterion is incorporated providing the ability to compare measurements made with different criteria (including different measurement techniques). Applicability of this model has been verified by experimental data obtained by direct transport and magnetisation measurements on high quality films grown by pulsed laser deposition. Pinning potential obtained from the fitting procedure is consistent with theoretical predictions. The model showed that the effective pinning landscape changes under influence of external conditions.

Application of Josephson effect in sensors, electronicand metrological devices working at temperature of 77 K requiresfabrication of efficient and reproducible high temperature superconducting(HTS) Josephson junctions. In order to enhancethe performance of HTS junctions, we introduce multilayeredapproach to YBCO-based step-edge Josephson junction manufacture.Thin YBCO and multilayered YBCO/NdBCO/YBCO filmsof a similar thickness (~210 nm) were grown by a pulsed-laserdeposition technique on MgO (100) substrates with artificiallycreated step edge. Large discrepancies of Ic and Rn values werefound between these two types of junction. Results of their structuraland electrical properties are reported.

A new critical current density (Jc) model for high-quality YBCO (YBa2Cu3O7) thin films has been proposed, combining thermally activated flux creep with a vortex pinning potential for columnar defects. The pinning for thermally activated vortices has been described as strong pinning on chains of individual edge dislocations that form low-angle domain boundaries in high-quality YBCO thin films. The model yields an adequate description of the Jc behaviour over the whole applied field range, as verified by direct measurements of Jc in YBCO thin films grown by pulsed-laser deposition. It also indicates that the effective pinning landscape changes under the influence of the external conditions. Remarkably, the pinning potential obtained from the model is consistent with the values obtained for columnar defects, which confirms the validity of the overall approach.

Comparative analysis of structural and electromagnetic characteristics have been performed on nano SiC- and polycarbosilane-doped MgB2 samples prepared by the dry and liquid mixing approaches. The total benefit of liquid mixing approach for fabrication of "organic" MgB2 superconductor with excellent electromagnetic performance has been demonstrated

Multilayered approach to YBCO-based Josephson junction manufacture is introduced. Properties of monolayer YBa2Cu3O7 (YBCO) and multilayer YBCO/NdBCO/YBCO junctions of similar thickness grown by pulsed-laser deposition on MgO (100) substrates has been analysed and compared. The influence of the multilayered structure on junction behaviour and properties are presented and discussed.

The universal approach of liquid mixing has been found to produce “organic” MgB2−xCx superconductors with structural and supercurrent-carrying properties unattainable by other techniques. We show by transmission electron microscopy combined with energy dispersive spectroscopy that these unique properties are enabled through coating of boron particles with a nanolayer of carbon. The subsequent reaction between carbon-encapsulated boron and magnesium results in enhanced carbon content x in the crystal lattice, as determined by x-ray diffraction pattern analysis. Among various carbon-containing compounds investigated, polycarbosilane has been found to be the optimal dopant for MgB2 superconductor, producing the largest critical current density due to the formation of wide range of nanodefects with pinning properties within the MgB2 crystal lattice, as well as due to minimal formation of current-blocking layers around the grains.

Discovered in 2001, MgB2 superconductor with the critical temperature of 39 K is one of the most promising candidates for high-current applications (magnets for magnetic resonance imaging, etc.). However, to utilize its properties, the current carrying ability of MgB2 should be enhanced. An important breakthrough is achieved by converting it into MgB2-xCx superconductor. This book describes extensive research efforts on development of MgB2- xCx superconductors and understanding their electromagnetic behaviour. Comprehensive study of microstructural and superconducting properties of MgB2 with different C-based dopants allowed us to (i) develop an advanced approach for the C-doping; (ii) classify a broad range of dopants and evaluate their effectiveness for enhancing the required properties of MgB2; (iii) identify factors affecting current-carrying ability in MgB2-xCx at high and low magnetic fields. This book should be of interest to a broad range of multidisciplinary scientists, engineers, technologists, product developers, and students dealing with MgB2 superconductor, its development, performance, and optimization for various practical applications.

Structural analysis and electromagnetic measurements have been performed on a range of samples prepared by the liquid mixing approach to doping MgB2 are sugar, malic acid, and polycarbosilane. The results obtained have allowed us to clarify the contributions of the factors limiting critical current at low magnetic fields in doped MgB2.

Discovered in 2001, magnesium diboride (MgB2) is the latest superconductor suitable for large scale applications (magnetic resonance imaging systems (MRI), fault current limiters (FCL), high-field magnets). Compared to other metallic superconductors like NbTi (Tc = 9 K) and Nb3Sn (Tc = 18 K), it has the advantage of a higher critical temperature (Tc = 39 K), which enables its application at the temperature of 20 K and, hence, significantly reduces the cost of the cooling system. This, together with the abundance of the magnesium and boron raw materials, as well as the relatively simple fabrication of MgB2 wires and tapes, has motivated the active investigation and study of this superconductor by many research groups all over the world. As a result, a significant breakthrough for application of MgB2 conductors at high fields has been made with introduction of carbon into the crystal lattice of MgB2 via chemical doping. The main focus of this work was on the study of the microstructural and superconducting properties of MgB2-xCx superconductors and establishing correlations between them. To obtain MgB2-x Cx compounds with different characteristics, various C-based doping materials and processing parameters were employed. The systematic study of the microstructural and superconducting properties of MgB2-x Cx samples conducted in this work allowed us: (i) to predict suitable dopants for MgB2; (ii) to improve chemical doping by carbon; (iii) to identify the relevant negative microstructural factors and estimate their effects on limitation of the current-carrying ability in MgB2-xCx samples. The results described in this work can be used as a guide for the achievement of the characteristics required for practical applications of MgB2 superconductors. Investigation of the properties of MgB2-xCx superconductors as a function of the processing parameters showed that the doping level, sintering temperature, and cooling time control the density of pinning centers in MgB2-xCx

In this paper we report the results of an extended study of the effect of sugar doping on the structural and electromagnetic properties of MgB2 superconductors. High values of the upper critical field (Bc2) of 36 T and the irreversibility field (Birr) of 27 T have been estimated at the temperature of 5 K in a bulk MgB2 sample with the addition of 10 wt% of sugar. The critical current density (Jc(Ba)) of sugar-doped samples has been significantly improved in the high field region. The value of transport Jc has reached as high as 108 A m-2 at 10 T and 5 K for Fe-sheathed sugar-doped MgB2 wire. The analysis of the pinning mechanism in the samples investigated indicated that dominant vortex pinning occurs on the surface type of pinning defects, such as grain boundaries, dislocations, stacking faults etc, for both pure and doped MgB2. In sugar-doped samples, pinning is governed by numerous crystal lattice defects, which appear in MgB2 grains as a result of crystal lattice distortion caused by carbon substitution for boron and nano-inclusions. The drastically improved superconducting properties of sugar-doped samples are also attributed to the highly homogeneous distribution and enhanced reactivity of this dopant with host Mg and B powders. The results of this work suggest that sugar is the optimal source of carbon for doping MgB2 superconductor, especially for application at high magnetic fields.

The effect of polycarbosilane (PCS) doping on the superconducting properties of MgB2 was systematically investigated. Highly reactive C and Si appeared after PCS decomposition facilitating incorporation of C into the MgB2 lattice, as well as the reaction between Si and Mg, resulting in formation of a large number of small Mg2Si particles within MgB2 grains. C-substitution induced crystal lattice defects and impurities act as strong pinning centers, significantly improving Jc(Ba) performance in the high field region. The differences in the effects of SiC and PCS doping have been studied and are described to the structural transformation that occurs in MgB2 after doping with these two materials.

MgB2 bulk samples containing different proportions of MgGa powder were prepared by an in situ reaction technique. The MgGa powder was obtained via high energy ball milling of a Mg10 at.% Ga composite, which was fabricated by melting of pure magnesium and gallium metals inside encapsulated stainless steel tube at 655 C in a controlled atmosphere. The MgB2 samples containing 0, 1, 3, 5 and 7 wt.% of MgGa addition were sintered at 650 C for 30 min in argon atmosphere. Magnetic measurements performed at 5 K and 20 K showed improved critical current density, Jc, in the low magnetic field range for samples with MgGa addition. The critical temperature, Tc, for all samples with gallium additions is consistently higher when compared to the pure MgB2.

We have systematically studied and compared the effect of cooling rate on microstructure, critical current density, upper critical field and irreversibility field in pure and 10 wt% SiC-added MgB2 superconductors. The sintering process was carried out on the samples at a temperature of 750 C for 1 h followed by quenching or cooling to room temperature in 0.3 h (2433 C h-1), 14 h (52 C h-1) and 25 h (30 C h-1). Changes in the microstructure due to variations in cooling rate have been studied with the help of scanning and transmission electron microscopy. Correlations between microstructure and superconducting properties have been observed, identified and explained for both pure and SiC-added MgB2 samples. Modifications to the pinning environment and grain boundary transparency are considered to be responsible for variations in the current-carrying ability. The dominant pinning on grain boundaries in the pure MgB2 samples and on nano-inclusions (inducing accompanying defects) in the SiC-doped samples is clearly distinguished. On the basis of our experimental results, we have concluded that the cooling rate can be an important parameter influencing the superconducting properties of MgB2 samples. >

A comparative study of pure, SiC, and C doped MgB2 wires has revealed that the SiC doping allowed C substitution and MgB2 formation to take place simultaneously at low temperatures. C substitution enhances Hc2, while the defects, small grain size, and nanoinclusions induced by C incorporation and low-temperature processing are responsible for the improvement in Jc. The irreversibility field (Hirr) for the SiC doped sample reached the benchmarking value of 10 T at 20 K, exceeding that of NbTi at 4.2 K. This dual reaction model also enables us to predict desirable dopants for enhancing the performance properties of MgB2.

Pure and 10 wt.% SiC added bulk MgB2 samples were sintered at 750 Degrees C for 1 h. Cooling of samples to room temperature was performed in different times (rates) such as 0 h (quench), 0.3 h (2433 Degrees C/h), 14 h (52 Degrees C/h), and 25 h (30 Degrees C/h). Correlations between changes in microstructure and superconducting properties have been observed and explained for both pure and SiC added MgB2 samples. On the basis of our experimental results, we have concluded that the cooling rate can be an important parameter influencing superconducting properties of MgB2 samples.

The effects of SiC and Carbon doping on the superconducting properties of MgB2 polycrystalline samples have been analysed by means of specific heat and magnetic relaxation measurements. It is known that the addition of nanometric powders of SiC and C leads to the enhancement of Birr and Jc. However, the underlying physical mechanism is not completely understood. Magnetic relaxation measurements did not show detectable effects of both the additions on the pinning properties of MgB2. It follows that doping acts mainly introducing disorder into the superconductor and thus raising Bc2. In the case of MgB1.9C0.1, specific heat measurements show that the C substitution on the B sites modifies the low temperature shoulder related to the second gap. This effect is not visible in the sample doped with SiC. From the distribution of Tc determined from the deconvolution of the calorimetric data, we argue that SiC leads to an inhomogeneous distribution of C.

A magnetic field of up to 12T was applied during the sintering process of pure MgB2 and carbon nanotube(CNT)dopedMgB2wires. The authors have demonstrated that magnetic field processing results in grain refinement, homogeneity, and enhancement in Jc(H) and Hirr. The extent of improvement in Jc increases with increasing field. The Jc for a 10T field processed CNTdoped sample increases by a factor of 3 at 10K and 8T and at 20K and 5T, respectively. Hirr for the 10T field processed CNTdoped sample reached 9T at 20K, which exceeded the best value of SiC dopedMgB2 at 20K. Magnetic field processing reduces the resistivity in CNTdopedMgB2, straightens the entangled CNTs, and improves the adherence between CNTs and the MgB2 matrix.