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Ferritic steel bars—25 mm in diameter—were welded by transient liquid phase bonding (TLPB) using Fe-based amorphous metallic foils as filler material. The resulting residual stress (RS) field shows a low peak magnitude—of 147 MPa—as measured by neutron diffraction. The most distinctive feature of TLPB is the heat input delivered simultaneously at the whole joint that allows much lower cooling rates compared with arc welding (AW). Therefore, the elapsed time between 800 and 500 °C (t 8/5) was particularly long reaching 390 s. As a result, a low RS peak magnitude (147 MPa) was obtained in the as-welded condition. This value is well below the RS peak magnitude obtained with AW which typically attain the yield strength of the base metal (276 MPa). The numerical simulation of RS at the welded bars was performed by a thermal and mechanical analysis. It shows that TLPB produced a large austenized region, low cooling rates and a remarkable t 8/5. Consequently, the large volume in which the heat input is delivered is the driving force to reduce RS peak magnitudes. From the mechanical analysis, it was found that the simulated RS was in good agreement with the measured RS. Therefore, the proposed numerical simulation model can be used to predict RS in TLPB weldments. [ABSTRACT FROM AUTHOR]

Better understanding how audience size influences emotions and behaviours during public performances is of particular importance since it may both impact the level of anxiety and quality of achievement of the performer and alter the degree of appreciation of the observer. We tested this question in a naturalistic setting by analyzing self-assessment questionnaires, Galvanic skin responses and behaviours of actors and spectators during theatrical representations with small, medium and large audiences. We found that: actors and spectators differed in their perception of the effects of audience size; the different components of emotions (cognitive, physiological, behavioural) were affected differently by audience size, which was also modulated by the individual's status; actors and spectators differed in their representation of the others' emotional state. Although our study remains exploratory, our findings highlight the complexity of the audience effect when comparing observers' and performers' emotions. [ABSTRACT FROM AUTHOR]

Structural analysis, magnetocaloric properties, and theoretical investigations of the magnetocaloric effect were carried out in the crystalline La0.7Ba0.15Ag0.15MnO3 manganite prepared using sol-gel route. The phase purity and structure of this sample were checked by X-ray diffraction technique and Rietveld analysis. From magnetic measurements, the ferromagnetic to paramagnetic (FM-PM) phase transition was observed around TC = 255 K. The maximum change in magnetic entropy (∆ S M max ) and relative cooling power (RCP) extracted from magnetic measurements were 3.48 J × kg-1 × K-1 and 225 J × kg-1 at an applied magnetic field of 5 T. These magnetocaloric parameters offer to the sample the possible use in the magnetic refrigeration technology. The magnetic entropy simulation by using different theories such as the Weiss molecular mean-field theory and the Landau theory shows good correlation between the theoretical values of −∆SM(T) and the experimental ones estimated from Maxwell relation. [ABSTRACT FROM AUTHOR]

In this study, we investigated the structure and magnetic properties of Nd0.88MnO3 (NMO) perovskite thin-film layers by liquid-injection metalorganic chemical vapor deposition (MOCVD) tried on SrTiO3 (STO) (100) substrates. The structural examinations showed that the growing film was amorphous. It changed to the crystalline phase after being annealed at 900°C in air for 24 h. A minor secondary phase identified as Mn3O4 appeared. The film was subjected to in-plane (IP) tensile stress leading to a contraction of the film's out-of-plane (OOP) lattice parameters. The orientation relationships for the film structure are described near the interface as 10 1 ¯ NMO// 100 STO and 010 NMO// 001 STO. The NMO thin film showed ferromagnetic ordering with a transition temperature TC = 85 K. The large bifurcation between ZFC and FC curves with a cusp at Tf = 53 K; and an irreversible temperature Tirr = 48 K proves that the spin-glass behavior with long-range ferromagnetic order (Mn3+-O2−-Mn4+) co-exists in NMO thin films. The magnetic easy axis corresponded to the surface normal. [ABSTRACT FROM AUTHOR]

In this work, an overview of the Weiss molecular mean-field theory, the Bean–Rodbell model and the Landau theory is presented, providing the theoretical background for simulating the magnetocaloric properties for La0.6Ca0.2Na0.2MnO3 manganite. Results showed that sample exhibits second-order ferromagnetic (FM)–paramagnetic (PM) magnetic phase transition and relatively higher values of magnetic entropy change (−∆SM). In application point of view, this material can be used in magnetic refrigeration technology. The theoretical values of −∆SM determined using each theory agree well with the experimental ones estimated from Maxwell relations. In other part, a good agreement in the spontaneous magnetization values, Mspont(T), estimated from (−∆SM vs. M2) and (H/M vs. M2) data was found. Also, the values of the critical exponent (β) found from both methods are close and check that the mean-field model is adequate to study the MCE in La0.6Ca0.2Na0.2MnO3 sample. [ABSTRACT FROM AUTHOR]

La0.6Ca0.2Na0.2MnO3 manganite was prepared using sol–gel method. Rietveld refinement of XRD pattern indicates that the prepared sample crystallizes in the rhombohedral R 3 ¯ c structure. The impendence spectroscopy properties of the sample were studied by performing a series of measurements as a function of temperature and frequency of conductivity, dielectric constants, modulus, and impedance. From these measurements, the metal–semiconductor behavior was observed for the sample at a transition temperature of the order of 240 K. The studies of imaginary part of permittivity and tangent loss reveal that the prepared material may be a good candidate for low-frequency energy storage devices. An electrical relaxation phenomenon with non-Debye nature was observed in variations of imaginary parts of modulus and impedance. Electrical parameters deduced from the Nyquist plots analyses using an equivalent circuit reveal that the conduction process for the sample was caused due to the grain boundaries contribution. [ABSTRACT FROM AUTHOR]

Ni0.4Cd0.3Zn0.3Fe2O4 ferrites have been prepared through the use of sol-gel method at 900 °C and 1100 °C. Rietveld refinements of XRD patterns indicate that the prepared samples crystallize in the cubic spinel structure. Lattice constant and grain size are found to increase with sintering temperature. Magnetic measurements show that the maximum magnetization (Ms) rises, whereas both coercivity (Hc) and remanence (Mr) decrease when increasing the sintering temperature. Frequency and temperature dependence of electrical conductivity, electrical modulus, and electrical impedance have been studied using impedance spectroscopy technique. As the sintering temperature increases, the conductivity of the samples increases. The variation of imaginary part of modulus (M″) displays the presence of an electrical relaxation phenomenon and non-Debye nature. Nyquist representations have been analyzed using an electrical equivalent circuit. The obtained results reveal that the conduction mechanism of the samples is achieved basically of the grain boundary contribution. [ABSTRACT FROM AUTHOR]

The results of structural, magnetic, critical, and magnetocaloric characterizations of La0.6Ca0.2Na0.2MnO3 perovskite have been reported. XRD analysis of the sample synthesized using sol-gel method shows good crystallization in the R 3 ¯ c rhombohedral structure. From M(T) curve, a second-order ferromagnetic-paramagnetic (FM-PM) phase transition appears at the Curie temperature (TC) around 275 K. Critical exponents (β, γ, and δ) have been evaluated using different techniques such as modified Arrott plots (MAP), Kouvel-Fisher (KF) method, and critical isotherm (CI). We found that the critical exponents of the prepared sample agree well with those of the mean-field model. We have also estimated the magnetic entropy change (−ΔSM) and relative cooling power (RCP) for the sample which obey power laws as −∆SM = a(μ0H)n and RCP = A(μ0H)N, respectively. ΔSM and RCP values were relatively higher, making the sample promising candidate for magnetic refrigeration technology. The estimated values of the magnetic ordering parameters (n and N) are used to confirm the reliability of the evaluated critical exponent. [ABSTRACT FROM AUTHOR]

We have reported the results of structural, magnetic, and magnetocaloric characterizations as well as the critical behaviors of the polycrystalline Nd0.67Pb0.33Mn0.9Al0.1O3 manganites. These samples, denoted as S900 and S1100, were prepared using the sol–gel method and sintered separately at 900 °C and 1100 °C, respectively. XRD analysis shows good crystallization for the samples in the R 3 ¯ c rhombohedral structure. From M(T) curves, second-order ferromagnetic–paramagnetic (FM–PM) phase transitions appear at the Curie temperatures (TC) around 130 K and 155 K for S900 and S1100, respectively. The estimated values of magnetic entropy change (−ΔSm) at μ0H = 5 T were found to be 3.23 and 4.41 J/kg.K for S900 and S1100, respectively. The corresponding values of relative cooling power (RCP) are equal to 242 and 245 J/kg. These values are relatively higher, making our samples promising candidates for magnetic refrigeration technology. We found that the critical exponents (β, γ, and δ) agree well with those of the mean-field and the 3D-Heisenberg models for S900 and S1100, respectively. [ABSTRACT FROM AUTHOR]

Ni0.6Cd0.2Cu0.2Fe2O4 ferrites were synthesized using sol-gel method under different sintering temperatures. XRD patterns with the Rietveld refinement indicate that samples crystallize in the cubic spinel structure. The increase of sintering temperature leads successively to the increase of lattice constant, average crystallite size, intensities of absorption bands, magnetization, and electrical conductivity of the prepared ferrites. Dielectric constants decrease with frequency and their behaviors have been investigated using the interfacial polarization theory predicted by Maxwell. The modulus analysis shows the presence of electrical relaxation phenomenon and non-Debye nature for the samples. An appropriate electrical equivalent circuit was used to analyze the Nyquist plots, and the results show that the conduction mechanism of the synthesized ferrites is mainly due to the grain boundary contribution. [ABSTRACT FROM AUTHOR]

"Audience effect" is the influence of an audience size or composition on the emotional state of a public speaker. One characteristic of the audience which has received little attention is the spatial position of observers. We tested the influence of three positions (frontal, bi-frontal, and quadri-frontal) on actors and spectators' emotions in real theatrical representations. Measurements consisted in self-report questionnaires and galvanic skin responses. The layout of the theatre hall influenced both cognitive and physiological components of emotions. Actors were more influenced than spectators and showed an overall accuracy in self-perception. The quadri-frontal audience received the highest scores in actors' feeling assessments and galvanic skin responses. In addition, we found a discrepancy between self-assessment of emotional states by spectators and how actors perceive them. Attention should thus be paid in the layout of performance places with obviously more attention from the public and better feelings for actors in more dispersed settings. [ABSTRACT FROM AUTHOR]

Detailed investigations of the microstructural, magnetic, magnetocaloric, and electrical properties of Ni0.4Mg0.3Cu0.3Fe2O4 ferrite synthesized by sol-gel method have been investigated. XRD pattern indicates that sample has cubic spinel structure with Fd 3 ̄ m symmetry. The cation distribution of the sample has been determined by Rietveld refinement. Temperature dependence of magnetization shows that sample exhibits a second-order PM to FM phase transition at the Curie temperature TC = 690 K. From the M(μ0H,T) data, we found that the maximum entropy change ΔS M max reaches value of about 1.56 J kg− 1 K− 1 and relative cooling power (RCP) of 136 J kg− 1 at μ0H = 5 T. From electrical conductivity curves, the estimated value of the activation energy is equal to 0.349 eV. The Nequist diagram at different temperatures reveals that the grain boundary contribution is responsible to the conduction process for the studied sample. [ABSTRACT FROM AUTHOR]

Purposes: The purpose of this study was to compare the efficacy of a mineral-rich solution vs normal saline solution (0.9% NaCl) following endoscopic complete bilateral ethmoidectomy.Methods: This was a prospective, multicenter, randomized, controlled, open-label trial in subjects suffering from steroid-resistant sinonasal polyposis. Adults performed 4 nasal irrigations of mineral or saline solutions daily for 28 days. Evaluations included subject-reported RHINO quality of life (QoL) and NOSE scores, tolerability, and satisfaction, the Lund-Kennedy endoscopic score and assessments of crusting, secretions and mucociliary clearance (rhinoscintigraphy).Results: A total of 189 subjects were randomized. Clinically relevant improvements (> 20 points) in RhinoQOL and NOSE scores were measured in both groups without any significant inter-group difference. Among the subjects with impaired RhinoQOL at pre-inclusion, the change in Impact-RhinoQOL score was significantly superior in mineral-rich vs saline solution at day 21 (p = 0.028) and day 28 (p = 0.027). The Lund-Kennedy score continuously improved in both groups earlier with the mineral-rich solution. Crusts were significantly fewer in number and less severe/obstructive in patients receiving mineral-rich vs saline solution at day 7 (p = 0.026) and day 14 (p = 0.016). Furthermore, secretions disappeared significantly more quickly and were less thick/purulent with mineral-rich solution at day 14 (p = 0.002) and day 21 (p = 0.043). Less epistaxis was reported in the mineral vs saline solution (p = 0.008 at day 21).Conclusions: Our findings indicate that the composition of a nasal irrigation solution influences endoscopic scores and QoL after sinus surgery for patients over 60, those with an initially poor QoL and higher symptom score, and smokers. [ABSTRACT FROM AUTHOR]

La0.6Sr0.2Na0.2MnO3 manganite was synthesized using sol-gel method. XRD pattern with Rietveld refinement indicates that sample crystallizes in the rhombohedral structure with R3¯c space group. The electrical conductivity analysis shows a metal-semiconductor transition temperature at TMS = 280 K for the sample. Dielectric constants decrease with frequency and their behaviors have been investigated according to the Maxwell-Wagner theory of interfacial polarization. An appropriate electrical equivalent circuit was used to analyze the Nyquist plots, and the results show that the conduction mechanism of the synthesized manganite is mainly due to the grain boundary contribution. The modulus analysis shows the presence of electrical relaxation phenomenon and non-Debye nature for the sample. The activation energy deduced from the conductivity analysis matches very well with the values estimated from the relaxation time and the grains boundary resistances. This indicates that relaxation process and electrical conductivity are attributed to the same defect. [ABSTRACT FROM AUTHOR]

A comparative study of microstructural, magnetic and electrical properties of Zn0.4Ni0.3Co0.3Fe2O4 (ZNCFO) and Zn0.4Cu0.3Co0.3Fe2O4 (ZCCFO) ferrites prepared using sol-gel method have been investigated in this work. X-ray diffraction results indicate that samples have cubic spinel type structure (Fd3¯m space group). Lattice constant, average grain size and X-ray density are higher for ZCCFO than those of ZNCFO. The magnetic parameters such as Ms, Hc, and Mr were found to decrease with the substitution of Ni by Cu. The electrical properties of the samples have been studied using impedance measurements as a function of frequency and temperature. The substitution of Zn-Co ferrite with Cu leads to improve its conductivity that its substitution with Ni. The behaviors of imaginary part of permittivity and loss tangent have been investigated using Maxwell-Wagner’s model and Koop’s theory. The electrical modulus study reveals the presence of the non-Debye type of dielectric relaxation in our samples. Close values of activation energy for dc conduction (Edc) and for conductivity relaxation (EMʺ) were found confirming that the relaxation process and electrical conductivity are attributed to the same defect. Nyquist representations (Z″ vs. Zʹ) were plotted and their characteristic behaviors were analyzed in terms of electrical equivalent circuit. [ABSTRACT FROM AUTHOR]

In this paper, we exploit the mean-field theory and the Bean-Rodbell model to justify the magnetocaloric effect (MCE) on Nd0.67Ba0.33Mn0.98Fe0.02O3 manganite. The modeling of magnetic properties was investigated. The Bean-Rodbell equation of state leads the system to second-order ferromagnetic (FM)-paramagnetic (PM) phase transition. The expressions describing the magnetic entropy change under the influence of magnetic field have been derived. A large magnetic entropy has been observed in our sample with a peak centered on the Curie temperature. The theoretical calculations are compared with experimental behavior. [ABSTRACT FROM AUTHOR]

Resistive switching (RS) is currently one of the hot topics in the frontier between materials science and microelectronics, crosslinking both research communities. Among the different types of RS phenomena that have been reported, this review focuses particularly on interface-type RS, for which the change in resistance is related to a modification in the materials properties occurring at the interface over the entire electrode area. In particular we have summarized the most interesting reports on perovskite oxides, a versatile oxide crystal structure which presents a plethora of functional properties depending on its exact composition and structural symmetry. We present the most relevant mechanisms inducing RS, such as valence change, due to a combination of oxygen vacancy drift and redox reactions; electronic correlations; and ferroelectricity. For each case we explain the physico-chemical processes triggered by the application of an external voltage (or current), which ultimately lead to a change in resistance at the interface between the metal electrode and the oxide. Special attention is paid to the material aspects of interface-type switching, and in particular to how the RS characteristics can be improved or triggered by cation doping and oxygen off-stoichiometry, by the introduction of additional layers and by changing the nature of the electrodes. Recent progress in memristive devices based on perovskites is also reported and the figures of merit reached are compared to those obtained for state-of-the-art filamentary type RS binary oxides. [ABSTRACT FROM AUTHOR]

We use particle-transport simulations to show that secondary pions play a crucial role for the development of the hadronic cascade and therefore for the production of neutrons and photons from thick spallation targets. In particular, for the n_TOF lead spallation target, irradiated with 20 GeV/ c protons, neutral pions are involved in the production of $ \sim 90\%$ of the high-energy photons; charged pions participate in $\sim 40\%$ of the integral neutron yield. Nevertheless, photon and neutron yields are shown to be relatively insensitive to large changes of the average pion multiplicity in the individual spallation reactions. We characterize this robustness as a peculiar property of hadronic cascades in thick targets. [ABSTRACT FROM AUTHOR]

Awara (Astrocaryum vulgare M.) pulp oil has been shown to possess anti-inflammatory properties in vivo, and contains an unsaponifiable matter rich in bioactive compounds. This study focused on the ethanolic unsaponifiable fraction (EUF) of awara pulp oil. Its chemical composition has been characterized: carotenoid, phytosterol, and tocopherol contents represent 125.7, 152.6, and 6.8 μg/mg of EUF, respectively. We further evaluated this fraction for anti-inflammatory properties in J774 macrophages activated by lipopolysaccharide (LPS) plus interferon (IFN) γ to understand the biological effects of awara pulp oil. EUF strongly decreased nitric oxide (NO), prostaglandin E(2), tumour necrosis factor (TNF) α, and interleukin (IL) -6 and -10 production in activated J774 cells. Moreover, it inhibited expression of inducible NO synthase and cyclooxygenases-2 in vitro. The anti-inflammatory properties of EUF were also confirmed in vivo by modulation of TNFα, IL-6 and IL-10 serum concentration in an endotoxic shock model. Pre-treatment with awara oil fraction offers promise as a protective means to lower the production of excessive amounts of pro-inflammatory molecules. [ABSTRACT FROM AUTHOR]

This article focuses on spallation reactions, i.e. interactions of energetic nucleons, basically with a kinetic energy in the 100MeV to a few GeV range, with a target nucleus. These processes are described rather successfully by the so-called Intranuclear Cascade (INC) plus evaporation models. They can be viewed as a first stage of nucleon-nucleon collisions, ejecting fast particles, followed by evaporation of slow particles from the target remnant. These cascade + evaporation models have, now, globally reached a high level of predictive power, owing in particular to successive research programs. The present work, which is an outcome of one of these programs, the recent European Union ANDES research program, deals with a set of reactions (or observable quantities), which can be due to a single collision, such as the one-nucleon removal reactions or the quasi-elastic elastic process. A survey of the experimental data is presented, which allows to clearly point out that, often, the INC models are unsatisfactory for the description of these peculiar events, whereas they are rather successful for the rest of the experimental data. This paradoxical situation is tentatively related to quasi-particle effects which are neglected in INC models. [ABSTRACT FROM AUTHOR]

We have carried out the structural properties, magnetization measurements and magnetocaloric effects in LaSrMnO perovskite prepared by the solid-state reaction formula. Crystallographic analysis was realized by Rietveld refinement of experimental X-ray diffraction data. Results show that this material has tetragonal crystal structure and exhibits a sharp ferromagnetic-paramagnetic (FM-PM) transition at a Curie temperature T (352 K). The experimental magnetic entropy change − ΔS and the relative cooling power (RCP) have been determined. The magnetocaloric data show a moderate low field magnetic entropy change above room temperature. In addition, the RCP values vary from 46.40 to 228.35 J kg upon variation of the applied magnetic field at 1 and 5 T, which is about 56% of the conventional refrigerant Gd material under 5 T. A good agreement is found between the experimental − ΔS and the one estimated by the Landau theory at the ferromagnetic region. However, the discrepancy at paramagnetic region was assigned to the contribution of itinerant electron to the large magnetic entropy change. [ABSTRACT FROM AUTHOR]

With the continuing development of nanomaterials, the assessment of their potential impact on human health, and especially human reproductive toxicity, is a major issue. The testicular biodistribution of nanoparticles remains poorly studied. This study investigated whether gold-silica nanoparticles could be detected in mouse testes after intramuscular injection, with a particular focus on their ability to cross the blood-testis barrier. To that purpose, well-characterized 70-nm gold core-silica shell nanoparticles were used to ensure sensitive detection using high-resolution techniques. Testes were collected at different time points corresponding to spermatogenesis stages in mice. Transmission electron microscopy and confocal microscopy were used for nanoparticle detection, and nanoparticle quantification was performed by atomic emission spectroscopy. All these techniques showed that no particles were able to reach the testes. Results accorded with the normal histological appearance of testes even at 45 days post sacrifice. High-resolution techniques did not detect 70-nm silica-gold nanoparticles in mouse testes after intramuscular injection. These results are reassuring about the safety of nanoparticles with regard to male human reproduction, especially in the context of nanomedicine. [ABSTRACT FROM AUTHOR]

The critical behavior of perovskite manganite LaBaMnFeO at the ferromagnetic-paramagnetic has been analyzed. The results show that the sample exhibited the second-order magnetic phase transition. The estimated critical exponents derived from the magnetic data using various such as modified d'Arrott plot Kouvel-Fisher method and critical magnetization M( T, H). The critical exponents values for the LaBaMnFeO are close to those expected from the mean field model β = 0.504 ± 0.01 with T = 275661 ± 0.447 (from the temperature dependence of the spontaneous magnetization below T), γ = 1.013 ± 0.017 with T = 276132 ± 0.452 (from the temperature dependence of the inverse initial susceptibility above T), and δ = 3.0403 ± 0.0003. Moreover, the critical exponents also obey the single scaling equation of M( H, ε) = | ε| f( H/| ε|). [ABSTRACT FROM AUTHOR]

Acid functionalization has been considered as an easy way to enhance the dispersion and biodegradation of carbon nanotubes (CNT). However, inconsistencies between toxicity studies of acid functionalized CNT remain unexplained. This could be due to a joint effect of the main physicochemical modifications resulting from an acid functionalization: addition of surface acid groups and purification from catalytic metallic impurities. In this study, the impact on CNT biotoxicity of these two physiochemical features was assessed separately. The in vitro biological response of RAW 264.7 macrophages was evaluated after exposure to 15-240 µg mL of two types of multi-walled CNT. For each type of CNT (small: 20 nm diameter, and big: 90 nm diameter), three different surface chemical properties were studied (total of six CNT samples): pristine, acid functionalized and desorbed. Desorbed CNT were purified by the acid functionalization but presented a very low amount of surface acid groups due to a thermal treatment under vacuum. A Janus effect of acid functionalization with two opposite impacts is highlighted. The CNT purification decreased the overall toxicity, while the surface acid groups intensified it when present at a specific threshold. These acid groups especially amplified the pro-inflammatory response. The threshold mechanism which seemed to regulate the impact of acid groups should be further studied to determine its value and potential link to the other physicochemical state of the CNT. The results suggest that, for a safer-design approach, the benefit-risk balance of an acid functionalization has to be considered, depending on the CNT primary state of purification. Further research should be conducted in this direction. Graphical abstract: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

The effect of Na substitution on nominal LaBaNaMnO (0≤ x≤0.33) manganites is studied in this work. Detailed chemical and structural analyses on ceramic samples obtained at 1200 C show that a significantly lower Na rate than the nominal one is obtained due to important Na losses during the synthesis. The losses of Na result in the appearance of impurity phases for high nominal Na rates in addition to the manganite phase with a rhombohedral $R\bar{3}c$ structure. Structural and physical properties of the samples can be properly interpreted according to the variation of the Mn/Mn ratio and the average ionic radius of A-site when the experimental composition of the manganite is considered. [ABSTRACT FROM AUTHOR]

This paper describes a numerical and experimental analysis of the process of water vapour absorption by a static lithium bromide solution. In the experiment, the temperature evolution of the absorbent solution is measured at different heights. The numerical model solves the set of governing equations for the simultaneous heat and mass transfer inside the absorbent by means of the finite-volume method. An iterative method is used to take into account the strong coupling of heat and mass transfer at the interface and variations of thermophysical properties. A moving grid technique is employed to represent the increase of the solution volume. Model results are compared with our measurements and data reported in the literature. The influence of using constant properties is analysed by comparison with the variable properties and experimental results. It is found that this assumption provides acceptable results in the investigated pool absorption cases despite a strong underestimation of the increase of the solution volume in the course of the absorption process. [ABSTRACT FROM AUTHOR]

We have investigated the dielectric properties of PrBaMnO (PBMO) and PrSrMnO (PSMO) perovskites synthesized by the solid-state reaction method at 1473 K. Samples were characterized by complex impedance spectroscopy (CIS) in the frequency range from 40 Hz to 1 MHz, at room temperature. The conductivity curves for the two samples were well fitted by the Jonscher law σ( ω)= σ+ Aω. For the PBMO sample, the hopping process occurs at long distance, whereas for PSMO compound it occurs between neighboring sites. Frequency dependence of dielectric constant ( ε″) and tangent loss (tan δ) show a dispersive behavior at low frequencies that was explained on the basis of the Maxwell-Wagner model and Koop's theory. Electric modulus formalism has been employed to study the relaxation dynamics of charge carriers. For both compounds, the variation of the imaginary part Z″ shows a peak at a relaxation angular frequency ( ω) related to the relaxation time ( τ) by τ=1/ ω. Nyquist plots of impedance show the presence of two semicircles and an electrical equivalent circuit has been proposed to explain the impedance results. [ABSTRACT FROM AUTHOR]

The analyses of resistivity experimental results of PrBaMnO (PBMO) and PrSrMnO (PSMO) manganites are presented. The electrical resistivity curves are fitted with the phenomenological percolation model, which is based on the phase segregation of ferromagnetic-metallic (FMM) clusters and paramagnetic-insulating (PMI) regions. The estimated results are in good agreement with experimental data. We found that the transition to the metallic state occurs if the volume fraction of the ferromagnetic phase reaches a percolation threshold, suggesting that the percolation of ferromagnetic (FM) domains is responsible for the observed metal-insulator (M-I) transition. According to the percolation model, we found that the energy gap of the quasi-particles in the phase separated FM and PM states is significantly smaller for PBMO than that for PSMO confirming that PSMO is more conductive than PBMO. We also found that the volume fraction of the ferromagnetic phase has the same physical meaning as the reduced magnetization. [ABSTRACT FROM AUTHOR]

The significant expansion in the use of nanoparticles and submicron particles during the last 20 years has led to increasing concern about their potential toxicity to humans and particularly their impact on male fertility. Currently, an insufficient number of studies have focused on the testicular biodistribution of particles. The aim of our study was to assess the distribution of 450 nm fluorescent particles in mouse testes after intramuscular injection. To this end, testes were removed from 5 groups of 3 mice each at 1 h (H1), 4 days (D4), 21 days (D21), 45 days (D45) and 90 days (D90) after the injection of 7.28 × 10 particles in the tibialis anterior muscles of each mouse. We examined histological sections from these samples by epifluorescence microscopy and confocal microscopy and identified testicular biodistribution of a small number of particles in groups H1, D4, D21, D45 and D90. Using CD11b immunostaining, we showed that particles were not carried into the testis by macrophages. The intratesticular repartition of particles mainly followed testicular vascularization. Finally, we found some particles in seminiferous tubules but could not determine if the blood-testis barrier was crossed. [ABSTRACT FROM AUTHOR]

Astatine isotopes can be produced in liquid lead-bismuth eutectic targets through proton-induced double charge exchange reactions on bismuth or in secondary helium-induced interactions. Models implemented into the most common high-energy transport codes generally have difficulties to correctly estimate their production yields as was shown recently by the ISOLDE Collaboration, which measured release rates from a lead-bismuth target irradiated by 1.4 and 1 GeV protons. In this paper, we first study the capability of the new version of the Liège intranuclear cascade model, INCL4.6, coupled to the deexcitation code ABLA07 to predict the different elementary reactions involved in the production of such isotopes through a detailed comparison of the model with the available experimental data from the literature. Although a few remaining deficiencies are identified, very satisfactory results are found, thanks in particular to improvements brought recently on the treatment of low-energy helium-induced reactions. The implementation of the models into MCNPX allows identifying the respective contributions of the different possible reaction channels in the ISOLDE case. Finally, the full simulation of the ISOLDE experiment is performed, taking into account the likely rather long diffusion time from the target, and compared with the measured diffusion rates for the different astatine isotopes, at the two studied energies, 1.4 and 1 GeV. The shape of the isotopic distribution is perfectly reproduced as well as the absolute release rates, assuming in the calculation a diffusion time between 5 and 10hours. This work finally shows that our model, thanks to the attention paid to the emission of high-energy clusters and to low-energy cluster induced reactions, can be safely used within MCNPX to predict isotopes with a charge larger than that of the target by two units in spallation targets, and, probably, more generally to isotopes created in secondary reactions induced by composite particles. [ABSTRACT FROM AUTHOR]

The relationship between particles' physicochemical parameters, their uptake by cells and their degree of biological toxicity represent a crucial issue, especially for the development of new technologies such as fabrication of micro- and nanoparticles in the promising field of drug delivery systems. This work was aimed at developing a proof-of-concept for a novel model of double fluorescence submicronic particles that could be spotted inside phagolysosomes. Fluorescein isothiocyanate (FITC) particles were synthesized and then conjugated with a fluorescent pHrodo™ probe, red fluorescence of which increases in acidic conditions such as within lysosomes. After validation in acellular conditions by spectral analysis with confocal microscopy and dynamic light scattering, quantification of phagocytosis was conducted on a macrophage cell line in vitro. The biological impact of pHrodo functionalization (cytotoxicity, inflammatory response, and oxidative stress) was also investigated. Results validate the proof-of-concept of double fluorescent particles (FITC + pHrodo), allowing detection of entirely engulfed pHrodo particles (green and red labeling). Moreover incorporation of pHrodo had no major effects on cytotoxicity compared to particles without pHrodo, making them a powerful tool for micro- and nanotechnologies. [ABSTRACT FROM AUTHOR]

Silicon carbide is an extremely hard, wear resistant, and thermally stable material with particular photoluminescence and interesting biocompatibility properties. For this reason, it is largely employed for industrial applications such as ceramics. More recently, nano-sized SiC particles were expected to enlarge their use in several fields such as composite supports, power electronics, biomaterials, etc. However, their large-scaled development is restricted by the potential toxicity of nanoparticles related to their manipulation and inhalation. This study aimed at synthesizing (by laser pyrolysis or sol-gel methods), characterizing physico-chemical properties of six samples of SiC nanopowders, then determining their in vitro biological impact(s). Using a macrophage cell line, toxicity was assessed in terms of cell membrane damage (LDH release), inflammatory effect (TNF-α production), and oxidative stress (reactive oxygen species generation). None of the six samples showed cytotoxicity while remarkable pro-oxidative reactions and inflammatory response were recorded, whose intensity appears related to the physico-chemical features of nano-sized SiC particles. In vitro data clearly showed an impact of the extent of nanoparticle surface area and the nature of crystalline phases (α-SiC vs. β-SiC) on the TNF-α production, a role of surface iron on free radical release, and of the oxidation state of the surface on cellular HO production. [ABSTRACT FROM AUTHOR]

The cross sections for nuclide production in thin Fe and Cr targets irradiated by 0.04-2.6-GeV protons are measured by direct γ spectrometry using two γ spectrometers with the resolutions of 1.8 and 1.7 keV for the Co 1332-keV γ line. As a result, 649 yields of radioactive residual product nuclei have been obtained. The Al( p, x)Na reaction has been used as a monitor reaction. The experimental data are compared with the MCNPX (BERTINI, ISABEL), CEM03.02, INCL4.2, INCL4.5, PHITS, and CASCADE07 calculations. [ABSTRACT FROM AUTHOR]

The cross sections for nuclide production in thin Nb and Ni targets irradiated by 0.04- to 2.6-GeV protons have been measured by direct γ spectrometry using two γ spectrometers with the resolutions of 1.8 and 1.7 keV in the Co 1332-keV γ line. As a result, 1112 yields of radioactive residual nuclei have been obtained. The Al( p, x)Na reaction has been used as a monitor reaction. The experimental data have been compared with the MCNPX (BERTINI, ISABEL), CEM03.02, INCL4.2, INCL4.5, PHITS, and CASCADE07 calculations. [ABSTRACT FROM AUTHOR]

The cross sections for nuclide production in thin Wand Ta targets irradiated by 0.04-2.6-GeV protons have been measured by direct γ spectrometry using two γ spectrometers with the resolutions of 1.8 and 1.7 keV in the Co 1332-keV γ line. As a result, 1895 yields of radioactive residual product nuclei have been obtained. The Al( p, x)Na reaction has been used as a monitor reaction. The experimental data have been compared with the MCNPX (BERTINI, ISABEL), CEM03.02, INCL4.2, INCL4.5, PHITS, and CASCADE07 calculations. [ABSTRACT FROM AUTHOR]

The cross sections for the production of Gd in W and Ta targets irradiated by 0.4-, 0.6-, 0.8-, 1.2-, 1.6-, and 2.6-GeV protons at the ITEP accelerator complex have been measured by direct α spectrometry without chemical separation. The experimental data have been compared with the data obtained at other laboratories and with the theoretical simulations of the yields on the basis of the BERTINI, ISABEL, CEM03.02, INCL4.2, INCL4.5, CASCADE07, and PHITS codes. [ABSTRACT FROM AUTHOR]

The spinal cord (SC) is a biosynthetic center for neurosteroids, including pregnenolone (PREG), progesterone (PROG), and 3α/5α-tetrahydroprogesterone (3α/5α-THP). In particular, anactive form of cytochrome P450 sidechain cleavage (P450scc) has been localized in sensory networks of the rat SC dorsal horn (DH). P450scc is the key enzyme catalyzing the conversion of cholesterol (CHOL) into PREG, the rate-limiting step in the biosynthesis of all classes of steroids. To determine whether neurosteroidogenesis might be involved in the pivotal role played by the DH in nociception, effects of neurogenic pain provoked by sciatic nerve ligature were investigated on P450scc expression, cellular distribution, and activity in the SC. P450scc mRNA concentration was threefold higher in the DH of neuropathic rats than in controls. The nerve ligature also increased the density of P450scc-positive neuronal perykarya and fibers in the ipsilateral DH. Incubation of spinal tissue homogenates with [3H]CHOL revealed that the amount of newly synthesized [3H]PREG from [3H]CHOL was 80% higher in the DH of neuropathic rats. Radioimmunoassays showed an increase of PREG and 3α/5α-THP concentrations in neuropathic rat DH. The upregulation of PREG and 3α/5α-THP biosynthesis might be involved in endogenous mechanisms triggered by neuropathic rats to cope with the chronic pain state. 3α/5α-THP formation from PREG can also generate PROG, which decreases sensitivity to pain and protects nerve cells against degeneration. Because apoptotic cell death has been demonstrated in the DH during neuropathic pain, activation of neurosteroidogenesis in spinal tissues might also be correlated to the neuroprotective role of steroids in the SC. [ABSTRACT FROM AUTHOR]

This article addresses the main predictors of adult education, using statistical methods different from those generally used by social science researchers. Its aim is twofold. First, it seeks to explain in a simple and comprehensible manner the methodological value of these methods (in relation to the use of structural models); secondly, it demonstrates the concrete usefulness of these methods on the basis of a recent piece of research on the data from the International Adult Literacy Survey (IALS). [ABSTRACT FROM AUTHOR]

The isotopic production cross sections of heavy residues in relativistic heavy-ion collisions have been investigated in inverse kinematics. The primary reaction products were fully identified in mass and atomic number prior to beta decay using the fragment separator FRS. The huge collection of data obtained helps in the understanding of the two main reaction mechanisms involved: fragmentation and fission. These data provide basic information for future radioactive ion beam facilities and for technical applications like intense neutron sources by means of spallation targets.© 2003 MAIK “Nauka / Interperiodica”. [ABSTRACT FROM AUTHOR]

Myelodysplastic syndromes (MDS) are characterized by abnormal growth of committed progenitors in clonogenic assay, with reduced number of colonies and decreased colony/cluster ratio. It has been suggested that excessive apoptosis is the cause of marrow failure in MDS. We studied the expression of caspase-1 (interleukin-1beta-converting enzyme, ICE) and caspase-3 (CPP32/apopain) in marrow mononuclear cells, and the growth pattern of committed progenitors in a series of 83 MDS cases. The percentage of apoptotic cells as detected by TUNEL technique, and the percentage of caspase-3-positive cells were significantly higher in refractory anemia (RA) and RA with ringed sideroblasts (RAS) than in chronic myelomonocytic leukemia (CMML), refractory anemia with excess of blasts (RAEB) and RAEB in transformation (RAEB-T). Spontaneous growth of CFU-GM was associated with a higher percentage of blasts, and with a lower expression of caspase-3 and caspase-1. The yield of CFU-E, BFU-E, and CFU-GM (in the presence of growth factors) was decreased by comparison to normal marrow, but large individual differences were observed in all cytological categories. Inhibition of caspase-1 and caspase-3 activities by specific inhibitors resulted in a significant increase of the production of all types of colonies (up to 50-fold of control). In the presence of caspase-3 inhibitor, the number of BFU-E and CFU-E was in the range of normal values in most cases of RA and RAS. In addition, caspase-1 and -3 protease activities were detectable by fluorogenic assay in all cases studied. Western blot analysis confirmed the expression of caspase-3, including the cleaved (activated)-p17 form in most cases of RA/RAS analyzed. It is concluded that caspase-3 is implicated in the increased apoptosis observed in MDS and that inhibition of its activity can restore at least partially the growth of committed progenitors. [ABSTRACT FROM AUTHOR]

Cold-finished carbon steel bars were bonded by means of the transient liquid phase bonding (TLPB) process using amorphous metallic foils of the eutectic Fe-B composition as filler material. A homogeneous microstructure throughout the joint was obtained. Traces of borides in the middle of the joint were the only distinguishable microconstituent from the base metal due to the TLPB process. The B concentration profile across the joint was measured by neutron radiography and was found to be composed of a central sharp peak with a maximum concentration of 15.9 ppm B superimposed over a broad peak (base width of ≈ 5 mm) with a maximum concentration of 13.3 ppm B. Owing to this low range of B concentrations, boride precipitation was almost suppressed, and only a scarce number of borides were observed at the joint. The resulting boride structure was identified as Fe23B6 by synchrotron microfocused X-ray diffraction, and its stabilization at room temperature is discussed. The bonded samples were subjected to a bend test, with a bending angle of 180°, and no cracks were observed. In tension tests, the bonded samples attained an ultimate tensile strength (UTS) of 434 MPa, an elongation of 32.3% and a reduction area q of 51.2%—78.6%, 165.6% and 75.4%, respectively, of the base metal. The fracture of the bonded samples occurred at the joint. It was determined that the decrease in UTS compared with that of the base metal was due to the recovery, recrystallization and grain growth that occurred during the TLPB thermal cycle. In addition, from fracture surface observation, it was found that the decrease in q in bonded samples was caused by the presence of traces of borides at the joint, which were the result of the liquid phase that solidified during the cooling stage.Graphical abstract: Cold-finished carbon steel bars were bonded by means of the transient liquid phase bonding (TLPB) process using amorphous metallic foils of the eutectic Fe-B composition as filler material. A homogeneous microstructure throughout the joint was obtained. Traces of borides in the middle of the joint were the only distinguishable microconstituent from the base metal due to the TLPB process. The B concentration profile across the joint was measured by neutron radiography and was found to be composed of a central sharp peak with a maximum concentration of 15.9 ppm B superimposed over a broad peak (base width of ≈ 5 mm) with a maximum concentration of 13.3 ppm B. Owing to this low range of B concentrations, boride precipitation was almost suppressed, and only a scarce number of borides were observed at the joint. The resulting boride structure was identified as Fe23B6 by synchrotron microfocused X-ray diffraction, and its stabilization at room temperature is discussed. The bonded samples were subjected to a bend test, with a bending angle of 180°, and no cracks were observed. In tension tests, the bonded samples attained an ultimate tensile strength (UTS) of 434 MPa, an elongation of 32.3% and a reduction area q of 51.2%—78.6%, 165.6% and 75.4%, respectively, of the base metal. The fracture of the bonded samples occurred at the joint. It was determined that the decrease in UTS compared with that of the base metal was due to the recovery, recrystallization and grain growth that occurred during the TLPB thermal cycle. In addition, from fracture surface observation, it was found that the decrease in q in bonded samples was caused by the presence of traces of borides at the joint, which were the result of the liquid phase that solidified during the cooling stage. [ABSTRACT FROM AUTHOR]

Cross sections for stripping and dissociation of deuterons interacting with Be targets in the 100–2300 MeV energy range have been measured. Comparisons with model calculations suggest a dominant contribution of the stripping process. It is also shown that the deuteron break-up cross section exhibits the same energy dependence as the nucleon-nucleon cross section. [ABSTRACT FROM AUTHOR]

Tensor analyzing powers iT, T, T and T, have been measured for deuteron laboratory energies E=75, 85, 95, 106, 119, 131, 144, 156, 172, and 187 MeV. The data are compared to rigorous Faddeev calculations with realistic nucleon-nucleon potentials. A generally good description of the data at all energies is obtained. [ABSTRACT FROM AUTHOR]

Angular distributions of analyzing powers Aand Ahave been measured in d-p elastic scattering at 70 MeV. The data are compared with Faddeev calcuiations using various tensor nucleon-nucleon interactions. [ABSTRACT FROM AUTHOR]