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Azorubine (E122), an azoic dye with the chemical formula C20H12N2Na2O7S2, has a wide range of applications in the food and cosmetic industries. Physical properties of azorubine were investigated by correlating the optical properties (refractive index, electric susceptibility and optical anisotropy) with the acidity study and biological activity. The optical study of azorubine shows that its refractive indexes are decreasing when the temperature of the solution is increased. The optical anisotropy of azorubine was observed/studied under polarized light at room temperature (RT). Azorubine exhibits the phenomenon of birefringence in results crystallites by drying and crystallization at RT of aqueous solution with concentration of 5%. THz spectroscopy identified the THz spectral “signature” of azorubine at a few wavelengths. The azorubine solution has, at a temperature of 24 °C, a weak alkaline character, corresponding to a pH = 7.14, and as the temperature increases, the acidity of the sample increases, the pH reaching value of 6.70 at the temperature of 55 °C. Five spectroscopic techniques were used to identify spectral properties of azorubine in powder and solution form: Fourier-transform infrared (FTIR), UV–Vis, Raman, laser fluorescence and THz spectroscopy. The morphology and chemical composition of azorubine were studied by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDXS). Thermal analysis effectuated in air indicates the evaporation of absorbed and physically bonded water up to 200 °C, after which the material possesses thermal stability up to 300 °C. Oxidative decomposition takes place in three exothermic steps between 300 and 687 °C; also, a high-temperature oxidation of the Na-based residues increases the mass above 815 °C. Azorubine has moderate biophysical activity when interacting with proteins (bovine serum albumin and collagen); the antioxidant activity of azorubine is increasing with increasing its concentration, while the phytotoxicity study indicates an overall inhibition of the wheat growth with increasing the concentration of azorubine and feeding time.

Ti-based composite materials with remarkable mechanical properties and good thermal stability were obtained and studied with the purpose of employment for producing resistant and versatile components in the automotive industry. The raw materials having the overall Ti80Mn8Al6Sn3Zr2C1 composition were prepared by mechanosynthesis from powders of comprising elements; after thermal processing and by following four different sintering pathways, both in the argon flow, the four samples (S1–S4) reached a specific composition of metallic and ceramic phases. Thermal analysis and calorimetry showed that the composite materials adsorb considerable amounts of argon, these being related to the obtained composition and microstructure. The results of the thermal study were used when choosing the thermal treatment conditions for sintering; in order to select the optimal processing conditions within the four different regimes of sintering for the raw materials and the final sample with the best functional properties, a comprehensive study for determining the composition, structure and morphological features was carried out by means of X-ray diffraction, energy-dispersive X-ray spectroscopy and scanning electron microscopy. Two samples (S1 & S4) of the obtained composite materials have increased porosity due to the presence of titanium aluminium carbides (Ti3AlC & Ti3AlC2) that are known as highly porous ceramics, therefore absorbing more argon during the preparation process. The roughness and wear tests showed that the best results (smallest roughness: Ra = 1.11 μm and smallest wear: w = 2.472·10−4 mm3 N−1 m−1) belong to the S2 sample sintered in argon for 15 min at 1100 °C and further calcinated at 1050 °C for 75 min.

The joint 5th Central and Eastern European Conference on Thermal Analysis and Calorimetry (CEEC-TAC5) & 14th Mediterranean Conference on Calorimetry and Thermal Analysis (Medicta 2019) was organized in Roma, the capital of Italy, from 27 to 30 of August 2019. The conference was dedicated to thermal analysis and calorimetry as an important system of capacities for solving diverse issues in different fields of science and applications. A wide range of topics was covered by 7 Plenary lectures and 16 Invited lectures ; there were 4 parallel sessions of 27 oral presentations each and 3 poster sessions with 106 posters each, totalizing 450 works. Besides the regular sessions, there were two workshops on Materials and respectively on Kinetics & Life time predictions, followed by an ICTAC Committee for Kinetics and an ICTAC committee for Materials round table. A special acknowledgement has to be addressed to the Journal of Thermal Analysis and Calorimetry (Prof. Imre Miklos Szilagyi, Prof. Alfred Kallay-Menyhard & Mrs. Sophie Korda) for publishing one more volume dedicated to this subject and to the reviewers that put all effort in enhancing the scientific quality of the volume...

JAM would like to acknowledge the School of Chemistry, University of St Andrews for the allocation of a PhD studentship through the EPSRC doctoral training grant (EP/K503162/1). AR would like to acknowledge support through the Strategic Grant POSDRU/159/1.5/S/133255, Project ID 133255 (2014), co-financed by the European Social Fund within the Sectorial Operational Program Human Resources Development 2007–2013 and also the University of Craiova and University of Cambridge for the mobility grant “Resonant ultrasound spectroscopy. (RUS) characterization of dielectric and ferroelectric tetragonal tungsten bronzes”. The work carried out at the University of St Andrews and University of Cambridge is part of an EPSRC- funded collaboration (EP/P02453X/1 and EP/P024904/1). The ‘empty’ tetragonal tungsten bronze Ba4La0.67 1.33Nb10O30 displays both relaxor-like and normal dielectric anomalies as a function of temperature; the former is associated with loss of ferroelectricity and was proposed to originate from anion disordering [Chem. Mater., 2016, 28 , 4616-4627]. Here we present total neutron scattering and pair distribution function (PDF) analysis which shows an increase in the distribution of oxygen-oxygen distances at the relaxor transition and which supports the proposed anion disordering mechanism. The disordering process can be destabilised by reducing the average A-cation size (i.e. Nd-doping: Ba4(La1-xNdx)0.67Nb10O30); this introduces a more strongly propagating tilt system in line with the previously reported crystal-chemical framework model [Chem. Mater., 2015, 27 , 3250-3261]. Mechanical loss data obtained using resonant ultrasound spectroscopy also indicate destabilisation of the disordering process with increasing Nd-substitution. Postprint

This paper presents an experimental investigation of a commercial shape memory alloy strip consisting of nickel and titanium (NiTi SMA), which correlates the thermal properties (phase transitions) with the electrical and mechanical properties of the material, allowing to be used for control applications in engineering. The bending performances of the SMA strip at different values of the activation electric current, during heating process, are also investigated. By using the differential scanning calorimetry (DSC) experiments, the thermal characteristics of the SMA strip were identified. The results of this thermal analysis were the basis for determining the equilibrium temperature, entropy and force developed by the SMA strip during the phase transformation. For the study of the SMA strip, the authors have developed an experimental platform, which uses a portable reconfigurable I/O (RIO) device and LabVIEW graphical programming environment for the measurement, testing and rapid control of parameters, and a piezo-film sensor for controlling of SMA strip movement. The real-time measurements and acquired waveforms are displayed on a PC screen, and the data associated with these waveforms are stored for later use, i.e. for applications in safety engineering like the fire extinguishing control, where very short response/activation times are required.

We identify the maximal chiral algebra of conformal cyclic orbifolds. In terms of this extended algebra, the orbifold is a rational and diagonal conformal field theory, provided the mother theory itself is also rational and diagonal. The operator content and operator product expansion of the cyclic orbifolds are revisited in terms of this algebra. The fusion rules and fusion numbers are computed via the Verlinde formula. This allows one to predict which conformal blocks appear in a given four-point function of twisted or untwisted operators, which is relevant for the computation of various entanglement measures in one-dimensional critical systems., Comment: 29+15 pages

We consider the entanglement entropy in critical one-dimensional quantum systems with open boundary conditions. We show that the second R\'enyi entropy of an interval away from the boundary can be computed exactly, provided the same conformal boundary condition is applied on both sides. The result involves the annulus partition function. We compare our exact result with numerical computations for the critical quantum Ising chain with open boundary conditions. We find excellent agreement, and we analyse in detail the finite-size corrections, which are known to be much larger than for a periodic system., Comment: 17+5 pages, 10 figures

In this work, some physical properties of a commercial Ni–Ti (nitinol) shape-memory alloy with cylindrical geometry (wire) were investigated; the focus was on the thermomechanical, calorimetric and magnetic characterization. By dynamical mechanical analysis, the range of elasticity, the elasticity–viscoelasticity coexistence domain and the domain in which a maximum force is applied were determined for the SMA wire. By using the temperature-modulated differential scanning calorimetry method, a multi-step temperature variation program was applied to the wire with cylindrical geometry, in two stages (heating–cooling) and through the interpretation of heat fluxes (reversible, nonreversible and total), and the phase transitions in the formation of martensite, austenite and rhombohedral phase (R-phase) were identified and correlated with those observed during the thermomechanical study; also, the formation of austenite and martensite was evidenced by the regular differential scanning calorimetry method; by magnetic measurements, it was established that the SMA wire had magnetic properties at room temperature, and the nitinol sample is paramagnetic and linear in the intensity of the magnetizing magnetic field; these results were compared with those previously obtained for the investigation of the nitinol SMA stripe.

Some physical properties like the thermal, thermomechanical, calorimetric, magnetic, and adhesive properties of a commercial shape memory alloy (SMA) with rectangular geometry were studied. Depending on the applied forces, there were identified range of elasticity, the elasticity–viscoelasticity coexistence domain, and the domain in which a maximum force of 18 N is applied, for the SMA strip. The controlled force module, in the tension mode, was used for the determination of the SMA strip elongation at application of the stretching forces from 0 to 13 N, at 30 °C, maintaining each static force value for 3 min. By employing the multi-frequency strain–stress modulus in the tension mode, DMA cyclic heating–cooling measurements were carried out. The measured dynamic mechanical properties for SMA strip were Storage Modulus, Loss Modulus, tanδ, and Stiffness, both at heating and cooling. Thus, the characteristic temperatures of the phase transitions (As, Af, Ms, Mf), of SMA strip were identified. Also, the values of the elasticity modulus (Young’s Modulus) of the SMA strip were calculated at 30 °C. With the DSC Q2000 device, using temperature-modulated differential scanning calorimetry method, a multi-step temperature variation program was applied to the rectangular strip in two stages (heating–cooling). Through the interpretation of heat fluxes (reversible, nonreversible, and total), the phase transitions in the formation of martensite, austenite, and also of the rhombohedral phase (R phase) and moreover enabled for the R phase identification, thermomechanical analysis confirmed the results obtained by classical DSC method. The adherence of some commercial azoic dyes on the rectangular SMA strip, as well as the modification of the surface roughness of the strip after the deposition of the dye, was also studied. By magnetic measurements, it was established that the SMA strip had magnetic properties at room temperature, in which magnetization is the sum of a superparamagnetic contribution and a paramagnetic term, linear in the intensity of the magnetizing magnetic field.

Two YBa 2 Cu 3 O 7-x materials (YBCO-I sintered at 1000 °C, and YBCO-II sintered at 960 °C and following special cooling programs) belonging to the orthorhombic system were obtained. YBCO-I has a complete volume texture, while for YBCO-II it is only on sample surface. On heating in air (with 10 K min −1 in the temperature range 20–1000 °C), two endothermic processes are recorded on DSC curves (of YBCO-II) and they are due to oxygen diffusion from O1 to O5 sites, and then to the release into the environment; second endothermic effect is attributed to the decomposition reaction. Different behaviour is encountered on heating in argon: an endothermic process in two steps; continuous mass decrease (oxygen loss) during argon cooling is recorded on the thermogravimetric curve. In argon atmosphere, the obtained material shall correspond to the chemical composition: YBa 2 Cu 3 O 6.77 , while in air atmosphere, the maximal composition than may be obtained is: YBa 2 Cu 3 O 6.88 . The barrier energies from Arrhenius plots of resistivity vs. temperature (91–93 K) show 2D (YBCO-I) and 3D (YBCO-II) behaviour for the thermally activated flow of melted vortex lattice, below the critical temperature.

Two yellow bis-azo dyes containing anthracene and two azodiphenylether groups (BPA and BTA) were prepared, and an extensive investigation of their physical, thermal and biological properties was carried out. The chemical structure was confirmed by the FTIR spectra, while from the UV&ndash, Vis spectra, the quantum efficiency of the laser fluorescence at the 476.5 nm was determined to be 0.33 (BPA) and 0.50 (BTA). The possible transitions between the energy levels of the electrons of the chemical elements were established, identifying the energies and the electronic configurations of the levels of transition. Both crystals are anisotropic, the optical phenomenon of double refraction of polarized light (birefringence) taking place. Images of maximum illumination and extinction were recorded when the crystals of the bis-azo compounds rotated by 90&deg, each, which confirms their birefringence. A morphologic study of the thin films deposited onto glass surfaces was performed, proving the good adhesion of both dyes. By thermal analysis and calorimetry, the melting temperatures were determined (~224&ndash, 225 &deg, C for both of them), as well as their decomposition pathways and thermal effects (enthalpy variations during undergoing processes), thus, good thermal stability was exhibited. The interaction of the two compounds with collagen in the suede was studied, as well as their antioxidant activity, advocating for good chemical stability and potential to be safely used as coloring agents in the food industry.

Recent advancements in biomedicine have focused on designing novel and stable interfaces that can drive a specific cellular response toward the requirements of medical devices or implants. Among these, in recent years, electroactive polymers (i.e., polyvinylidene fluoride or PVDF) have caught the attention within the biomedical applications sector, due to their insolubility, stability in biological media, in vitro and in vivo non-toxicity, or even piezoelectric properties. However, the main disadvantage of PVDF-based bio-interfaces is related to the absence of the functional groups on the fluoropolymer and their hydrophobic character leading to a deficiency of cell adhesion and proliferation. This work was aimed at obtaining hydrophilic functional PVDF polymer coatings by using, for the first time, the one-step, matrix-assisted pulsed evaporation (MAPLE) method, testing the need of a post-deposition thermal treatment and analyzing their preliminary capacity to support MC3T3-E1 pre-osteoblast cell survival. As osteoblast cells are known to prefer rough surfaces, MAPLE deposition parameters were studied for obtaining coatings with roughness of tens to hundreds of nm, while maintaining the chemical properties similar to those of the pristine material. The in vitro studies indicated that all surfaces supported the survival of viable osteoblasts with active metabolisms, similar to the &ldquo, control&rdquo, sample, with no major differences regarding the thermally treated materials, this eliminates the need to use a secondary step for obtaining hydrophilic PVDF coatings. The physical-chemical characteristics of the thin films, along with the in vitro analyses, suggest that MAPLE is an adequate technique for fabricating PVDF thin films for further bio-applications.

The food-colouring dye tartrazine is a significant additive and in the same time a biologically active material. Thermal behaviour of trisodium (4E)-5-oxo-1-(4-sulphonatophenyl)-4-[(4-sulphonatophenyl)hydrazono]-3-pyrazole carboxylate, tartrazine or E102 as it is also known, was studied in relation with the physical, chemical, thermal and biophysical (interaction with proteins, antioxidant and phytotoxicity) properties. Tartrazine structure and microstructure have been determined by X-ray diffraction and scanning electron microscopy investigations. Tartrazine has a monoclinic crystalline structure (space group C2/c). Electronic transitions and atomic bonds behaviour in molecules and fluorescent excitation of the compound have been identified by spectroscopic methods: Fourier-transformed infrared, UV–Vis, atomic fluorescence and Raman spectroscopies. Tartrazine absorbs in the visible region at 436.36 nm and shows laser fluorescence of all its elements. Chemical (acidity) and optical properties (refractive index and electric susceptibility) were determined for different concentrations on a sensitive range of temperatures. Thermal analysis measurements of tartrazine revealed thermal stability until 200 °C in air, while in the inert environment (argon) the stability is increased to 300 °C. Biological and biophysical activities and properties of tartrazine have been evidenced through its interaction with animal proteins, comparison with the standard gallic acid and phytotoxicity towards wheat strains/roots, when several concentrations of tartrazine solutions were used. Tartrazine has moderate biological activity when interacting with proteins, obtained antioxidant activity above a threshold concentration of 0.25% and presents plant growth phytotoxicity.

Although there is a diversity of publicly available datasets for autonomous driving, from small-scale to larger collections with thousands of miles of driving, we consider that the process of collecting and processing them is often overlooked in the literature. From a data-driven perspective, quality of a dataset has proven as important as quantity especially when evaluating self-driving technologies where safety is crucial. In this paper, we provide a guideline going through all the steps from configuring the hardware setup to obtaining a clean dataset. We describe the data collection scenario design, the hardware and software employed in the process, the challenges that must be considered, data filtering and validation stage. This work stems from our experience in collecting the UPB campus driving dataset released together with this work. It is our belief that having a clean and efficient process of collecting a small but meaningful dataset has the potential to improve benchmarking autonomous driving solutions, capturing local environment particularities.

The authors would like to thank to the following funding organisations: the Royal Society for providing a research fellowship (F.D.M.), EPSRC for providing the PhD student grant (A.R.) and Roberto Rocca Education Program for providing an additional fellowship grant (A.R.). The electrical properties of a family of tetragonal tungsten bronze (TTB) materials, Ba6Sc1-xInxNb9O30 (x = 0.25, 0.5, 0.75), which display relaxor properties were characterised using high-temperature impedance spectroscopy and low-temperature dielectric spectroscopy. All powders were synthesized at 1250°C (24hours) + 1350°C (6.5hours), while the pellets were further sintered at 1350°C (12hours). At high temperature, the electrical conductivity in all samples is dominated by a single response, attributed to the bulk response, while the subtle asymmetry of the imaginary impedance peak suggests a minor contribution of the grain boundary response. In general, the Sc-In solid solutions samples exhibit similar electrical behaviour to the Sc compound, x = 1 reported previously (Ceram. Int. 2016, 42, 11810–11821). At low temperature all compounds exhibit frequency dependent relaxor behaviour. With increasing the content of In, the dielectric peaks are more asymmetric and the curves flatten more at temperatures above the transition temperature. The dipole freezing temperature, TVF, determined by Vogel-Fulcher (VF) analysis does not simply increases linearly as a function of M3+ (Sc3+,In3+) cation size, the extrapolation of VF-like curves results in considerably different values when compared to those found previously, since the acquired dielectric data are very sensitive to preparative conditions. Postprint

Azoic dyes are compounds of interest from the point of view of their potential applications, such as the use of liquid crystals in optoelectronic and organic electroluminescent devices, or may be employed as template matrices for producing high-aspect ratio inorganic nanomaterials. Herein, 4-[(4-chlorobenzyl)oxy]-3,4′-dichloroazobenzene azoic dye, known as CODA, is selected as a choice compound among such materials due to its liquid crystalline properties and may be further used as nanostructured material in various applications. Thermokinetic study of CODA azoic dye thermal decomposition in air flow atmosphere was performed by employing thermogravimetric data; the kinetic parameters of the two decomposition steps were obtained under non-isothermal linear regimes, by means of multi-heating rates methods. Differential and integral “model-free” kinetic methods like Friedmann, Kissinger–Akahira–Sunose and Ortega, the invariant kinetic parameters method and the Perez-Maqueda et al. criterion (by Coats–Redfern and differential equations) were used. The kinetic study reveals very different behaviour related to the two decomposition steps of CODA, with complex processes composed of more than one kinetic mechanism for each of those, as indicated also by the Gotor et al. master plot method. Modern devices incorporating such materials tend to use them as thin films due to their specific properties; the CODA thin films were deposited on silicon substrates by matrix-assisted pulsed laser evaporation technique, using a Nd:YAG laser working at the wavelength of 266 nm. The preservation of the CODA compound after the transfer on the substrates was confirmed by Fourier transform infrared spectroscopy, while the morphology and topography of the deposited materials and of the thin film surfaces were investigated by atomic force microscopy and optical microscopy.

In this study, hydroxyapatite–alendronate composites were synthesized from calcium nitrate, diammonium hydrogen phosphate and alendronate by chemical precipitation method. The obtained materials were analysed by physical–chemical methods, while the compositional and structural characteristics of hydroxyapatite–alendronate phases were determined by a combination of crystallographic, spectroscopic and thermal analysis investigations; moreover, the alendronate content, its maximal incorporation efficiency to hydroxyapatite and stability were determined. A two-level full factorial design was chosen to determine the optimum set of process parameters (synthesis temperature, reactant addition rate and ripening time) and their effects on various hydroxyapatite–alendronate characteristics: alendronate incorporation efficiency, hydroxyapatite crystallite size (XRD), hydroxyapatite particle size distribution (DLS). These effects were quantified using design of experiments. The in vitro release profile of alendronate from hydroxyapatite–alendronate tablets was assessed.

The authors would like to thank to the following funding organisations: the Royal Society for providing a research fellowship (F.D.M.), EPSRC for providing the PhD student grant (A.R.) and Roberto Rocca Education Program for providing an additional fellowship (A.R.). This work reports on the microstructural and high-temperature impedance spectroscopy study of a family of dielectric ceramics Ba6MNb9O30 (M=Ga, Sc, In) of tetragonal tungsten bronze (TTB) structure with relaxor properties. For Ba6GaNb9O30 and Ba6InNb9O30 pellets, the SEM images have revealed good, dense internal microstructures, with well-bonded grains and only discrete porosity; in contrast Ba6ScNb9O30 pellets had a poorer microstructure, with many small and poorly-bonded grains gathered in agglomerates, resulting in significant continuous porosity and poorly defined grain boundary regions. The electroactive regions were characterised by the bulk and grain boundaries capacitances and resistances, while their contribution to the electrical conduction process was estimated by determining activation energies from the temperature (Arrhenius) dependence of both electric conductivities and time constants. For Ga and In analogues the electronic conductivity are dominated by the bulk response, while for Sc analogue, the poorly defined grain boundaries give a bulk-like response, mixing with the main bulk contribution. Postprint

This study comes to complete the initial investigation of the liquid crystalline properties of 4-[(4-chlorobenzyl)oxy]-3,4′-dichloroazobenzene (CODA). Here, the thermal analysis of CODA dye was performed in air flow and nitrogen flow atmospheres by means of simultaneous thermogravimetry TG, derivative thermogravimetry DTG, differential thermal analysis DTA and differential scanning calorimetry DSC; differences between the two steps of the thermal degradation of CODA related to the two experimental atmospheres were observed. Drops cast and spin coating techniques were used for nanostructuring CODA on platinum (Pt) substrates; the deposited materials were characterised by atomic force microscopy (AFM) and scanning electron microscopy (SEM). Exotic crystalline nanowires of CODA were obtained as function of used deposition technique, while the deposition time decisively influenced their features. The present results advocate for employing these materials as template matrices for producing high-aspect-ratio inorganic nanomaterials (i.e. Au) in the form of nanotubes, nanowires, nanorods or nanoparticles with enhanced functional properties.

Boric acid is a very important inorganic material with diverse uses in optoelectronics, petroleum industry, medicine, agriculture, etc. Recently, it was reported on the modification of the crystallization system of the triclinic boric acid (TBA) to hexagonal boric acid (HBA), when a special obtaining procedure is applied. In this paper, the thermokinetic stability of HBA novel material was comparatively studied with respect to the well-known TBA, in air flow atmosphere. Both HBA and TBA undergo a three-step overall thermal decomposition reaction (dehydration), following similar pathways; from the thermodynamic point of view HBA is more stable—decomposition temperatures and ΔH are higher in this case compared to those of TBA. The kinetic analysis was performed by means of the isoconversional methods, for each step of dehydration observing different thermokinetic regions. Higher thermal stability for HBA enables it to be employed at higher temperatures instead of TBA, explaining why the triclinic symmetry enhances the formation actually of the pseudo-hexagonal crystals as crystal habit at the macroscopic scale. Lower thermodynamic and kinetic stability of HBA makes it easier to be activated and thus more instable at the microstructural scale: this is an indirect proof of the TBA presence in the usual surrounding conditions and in the same time raises the probability for HBA molecules to slide onto their crystalline layers due to the lability of hydrogen bonds keeping them and thus increased potential to intercalate with other molecules. The present results open the possibility for promising applications of HBA as a better lubricant for various industries, while in the medical sector superior cleanser, antifungal and antibacterial properties may be foreseen.

Kinetics of heterogeneous processes of materials is an important topic of thermal analysis field; it directly describes the dynamics of condensed matter systems, revealing “hot insights” of materials towards a better understanding of their structural, functional and transition-related properties. The advanced thermal and kinetic software by standard procedure TKS-SP 2.0 was successfully employed to perform kinetic computations, by making use of an extended spectrum of procedures, methods and discrimination criteria, it produces in real-time, high-volume and accurate sets of kinetic data from thermally induced processes. The discrimination between the kinetic models and the selection of the appropriate one is explained here in an in-depth study, employing the Perez-Maqueda et al. criterion under both integral and differential procedures in combination with the Gotor et al. master plots method. Perez-Maqueda et al. criterion describes the independence of the kinetic parameters from the heating rate, while the master plots method of Gotor et al. give the fastest way to check the kinetic models just by fitting in a continuous and visual manner the normalised transformation rate of a chemical or physical process with the relation ([f(α)·g(α)]/[f(α max)·g(α max)])—where the adjustment of the step of the kinetic model and of the values for the conversion degree at the maximal conversion rate inside the relation is performed. A working procedure is proposed to be applied for the step-by-step evaluations, discrimination and selection of the unique kinetic triplet {E, A, f(α)} corresponding to a certain investigated process.

Tetragonal tungsten bronze (TTB) structures offer some promise as lead-free ferroelectrics and have an advantage of great flexibility in terms of accessible composition ranges due to the number of crystallographic sites available for chemical substitution. The ferroic properties of interest are coupled with strain, which will be important in the context of stability, switching dynamics and thin film properties. Coupling of strain with the ferroelectric order parameter gives rise to changes in elastic properties, and these have been investigated for a ceramic sample of Ba6GaNb9O30 (BGNO) by resonant ultrasound spectroscopy. Room temperature values of the shear and bulk moduli for BGNO are rather higher than for TTBs with related composition which are orthorhombic at room temperature, consistent with suppression of the ferroelectric transition. Instead, a broad, rounded minimum in the shear modulus measured at ~1 MHz is accompanied by a broad rounded maximum in acoustic loss near 115 K and signifies relaxor freezing behaviour. Elastic softening with falling temperature from room temperature, ahead of the freezing interval, is attributed to the development of dynamical polar nanoregions (PNRs), whilst the nonlinear stiffening below ~115 K is consistent with a spectrum of relaxation times for freezing of the PNR microstructure.

Enterosorbents are widely-used materials for human body detoxification, which function by immobilizing and eliminating endogenous and exogenous toxins. Here, activated carbons, obtained from the lignocellulosic raw vegetal materials of indigenous provenance, have been studied. Walnut shell and wood from local species of nuts and apple-trees were carbonized, and further activated at high temperatures with water vapors in a rotary kiln. A second activation was carried out, in a fluidized bed reactor, but for shorter times. The textural properties of the samples were determined from the adsorption isotherms of nitrogen at 77 K, allowing the obtaining of highly mesoporous materials, while the adsorption capacity permitted an essential rise of six to seven times in the maximal adsorption values of the metabolites, which was determined by the reactivation process. A kinetic study of vitamin B12 and creatinine immobilization was performed, the optimal immobilization time for the apple-tree wood reactivated carbons being 2 times longer than for those originating from walnut shells. An additional investigation was also performed in specific conditions that simulate the real environment of immobilization: the temperature of a febrile human body (at the temperature T = 38 &deg, C) and the characteristic acidity of the urinary tract and stomach (at the pH of 5.68 and 2.53, respectively). The activated carbonic adsorbents studied here, together with the results of the immobilization studies, show that these procedures can conduct a good incorporation of some endogenous metabolic products, such as vitamin B12 and creatinine, therefore presenting a good opportunity for their use as forthcoming commercial enterosorbents.

Seven new coordination polymers [Zn(I)2(4-bpmhz)]n (1), [Cd(I)2(4-bpmhz)]n (2), [Zn(I)2(3-bpmhz)]n (3), [Cd(I)2(3-bpmhz)2]n (4), [Zn(NO3)2(H2O)2(4-bpmhz)]n·0.5n(EtOH) (5), [Cd(NO3)2(4-bpmhz)3/2(MeOH)]n·0.5nH2O (6) and [Zn(NO3)2(3-bpmhz)2]n (7) were prepared following the reactions of the zinc and cadmium iodide or nitrate salts with the methylated azine ligands of the bis-monodentate N,N′-donor type, 1,2-bis(1-(pyridin-4-yl)ethylidene)hydrazine (4-bpmhz) and 1,2-bis(1-(pyridin-3-yl)ethylidene)hydrazine (3-bpmhz). The single-crystal X-ray diffraction studies show that compounds 1–5, and 7 display 1D chain structures, while compound 6 shows a 2D coordination network, and both 4-bpmhz and 3-bpmhz act as bidentate bridging ligands. The crystals 1 and 2 are isomorphous, and differ by the metal cation only. The single coordination chains in 1–3 have zigzag structures; they are linear in 5, while 4 and 7 display similar double-chain structures. The crystal packing in 5 and 6 provides cavities occupied by solvent molecules, ethanol and water. The compounds were characterized in the solid state and in solution by spectroscopic (FTIR, UV–Vis, NMR) methods; the solid state emissive properties were studied for all compounds, while their thermal stability and behaviour were investigated by thermogravimetry under inert atmosphere, while the thermochromism for several compounds was registered and discussed.

nema

New zinc(II) 2-aminobenzoate complexes with general formula Zn(2-NH2benz)2(L)2 (where 2-NH2benz is 2-aminobenzoate, and L is phenazone, N-methylnicotinamide, nicotinamide and isonicotinamide) were prepared and characterized by elemental analysis and by FTIR spectroscopy. The stability and thermal behaviour of the compounds were studied by thermal analysis techniques (TG/DTG, DTA), and the decomposition reactions were proposed. The decomposition of the studied compounds is always a multistep process, when after the release of the bioactive ligand, 2-aminobenzenecarbaldehyde, 2-aminobenzene and carbon dioxide were evolved. The solid intermediate compounds were confirmed by FTIR spectroscopy, and the volatile products were identified by mass spectrometry. The final solid product of thermal decompositions was zinc oxide, which was confirmed by XRD and FTIR analysis. The non-isothermal kinetic investigation of Zn(2-NH2benz)2(mnad)2 decomposition in air was performed by means of isoconversional methods, for a better understanding of the undergoing processes. The antimicrobial assay was carried out comparatively for the investigated compounds; they have higher biological activity towards Staphylococcus aureus, Escherichia coli and Candida albicans in comparison with zinc(II) 4-bromobenzoates.