Structural and electrical properties of Ti doped α-Fe2O3

In this work we have analyzed the effects of Ti doping on structural and electrical properties of α-Fe2O3. When the amount of added Ti (5 wt.%TiO2) was within the solubility degree and XRD, SEM and EDS analysis revealed a homogenous hematite structure, with lattice parameters a= 5.03719(3) Å, c=13.7484(1) Å slightly increased due to incorporation of Ti into the rhombohedral hematite lattice. Higher amounts of Ti (10 wt.%TiO2) resulted in the formation of pseudobrookite, besides hematite, confirmed by SEM and EDS analysis. Studies of electric properties in the temperature range 25-225oC at different frequencies (100 - 1Mz) showed that Ti doping improved electrical conductivity. Impedance analysis was performed using an equivalent circuit, showing one relaxation process and suggesting dominant grain boundary contribution. [Projekat Ministarstva nauke Republike Srbije, br. III45014 i br. III43008

Long-Baseline Neutrino Facility (LBNF) and Deep Underground Neutrino Experiment (DUNE) Conceptual Design Report Volume 2: The Physics Program for DUNE at LBNF

The Physics Program for the Deep Underground Neutrino Experiment (DUNE) at the Fermilab Long-Baseline Neutrino Facility (LBNF) is described

Isothermal kinetics of titanium-oxo-alkoxy clusters formation

In this article, the influences of titanium tetraisopropoxide Ti(OR)4 (R = Pri) concentration, molar ratio, h = [H2O]/[Ti(OR)4], and temperature, on the formation kinetics of the titanium-oxo-alkoxy clusters (TOAC), were studied. The TOAC formation isothermal kinetics was monitored by measuring absorbance changes versus time in the reaction mixture at predefined wavelength λ = 350 nm. It was determined that the isothermal rate of clusters formation is a power law function of titanium tetraisopropoxide concentration and the molar concentration of water (cw). The kinetic parameters α and β were calculated. The apparent activation energy Ea values in the clusters formation reaction has been calculated and correlated with the change of titanium tetraisopropoxide concentration and molar ratio. The model for mechanism of TOAC formation is proposed.U ovom radu ispitivani su uticaji koncentracije, titan izopropoksida Ti(OR)4 (R = Pri), molskog odnosa, h = [H2O]/[Ti(OR)4], i temperature,na kinetiku formiranja titan okso-alkoksi klastera (TOAC). Izotermna kinetika formiranja TOAC praćena je snimanjem promene apsorbanse sa vremenom u reakcionoj smeši, na predefinisanoj talasnoj dužini λ = 350 nm. Utvrđeno je da je brzina izotermnog formiranja klastera stepena funkcija koncentracije titan izopropoksida i molarne koncentracije vode (cw). Kinetički parametri α i β su izračunati. Vrednosti prividne energije aktivacije Ea u reakciji formiranja klastera su izračunate i povezane sa promenama koncentracije titan izopropoksida i molskog odnosa h. Predložen je model mehanizma formiranja TOAC

Spazi e radici tra Citt\ue0 e Campagna nelle Nuove Contraddizioni

Tratta dell'insediamento umano definito dai centri storici della costa tirrenica della provincia di Cosenza. Oltre alla descrizione della realt\ue0 dei centri storici si analizza una ipotesi d'uso del patrimonio edilizio non utilizzato al fine di promuovere nuove forme di stanzialit\ue0 turistica. L'analisi sulla domanda di turismo tiene conto della condizione contemporanea che produce uno straniamento delle radici. Il progetto pertanto fonda le sue intenzioni nella ricostruzione di radici universali che pososno essere ritorvate nelle forme di abitazione proprie del costruito storico

Analysis and modeling of sintering of Sr-hexaferrite produced by PIM technology

The powder injection moulding (PIM) technology is lately becoming more and more significant due to complex design possibilities and good repeatability. This technology requires optimization of all steps starting with material and binder, injection, debinding and sintering parameters. Sintering is one of the key links in this technology. The powder injection moulding process is specific as during feedstock injection powder particles mixed into the binder do not come into mechanical contact. Shrinkage during sintering of PIM samples is high. In this work we have analyzed and modeled the sintering process of isotropic PIM samples of Sr-hexaferrite. The Master Sintering Curve (MSC) principle has been applied to analyze sintering of two types of PIM Sr-hexaferrite samples with completely removed binder and only the extraction step of the debinding procedure (thermal debinding proceeding simultaneously with sintering). Influence of the heating rate on resulting sample microstructures has also been analyzed. Influence of the sintering time and temperature was analyzed using three different phenomenological equations

Study of dielectric behavior and electrical properties of hematite α-Fe2O3 doped with Zn

The effects of Zn-doping on the dielectric behavior and electrical properties of bulk α-Fe2O3 have been studied. X-ray diffraction analysis revealed the presence of two phases in all samples: hematite and spinel ZnFe2O4, with the amount of spinel phase increasing with increasing Zn content. Scanning electron microscopy analysis combined with energy dispersive X-ray spectroscopy showed that the Zn-bearing phase occurred in the form of individual spinel ZnFe2O4 grains in a hematite matrix. DC conductivity was measured in the temperature range 25-225oC (298-498 K). Impedance spectroscopy measurements in the same temperature range were carried out in the frequency range 100Hz to 10 MHz. Increase in the Zn content resulted in increased electrical conductivity and higher values of the dielectric constant. The resistance and capacitance of grains and grain boundaries were analyzed by modeling the experimental results using an equivalent circuit. [Projekat Ministarstva nauke Republike Srbije, br. III 45014

Model-Based Motion Filtering for Improving Arm Gesture Recognition Performance

We describe a model-based motion filtering process that when applied to human arm motion data leads to improved arm gesture recognition. By arm gestures, we mean movements of the arm (and positional placement of the hand) that may or may not have any meaningful intent. Arm movements or gestures can be viewed as responses to muscle actuations that are guided by responses of the nervous system. Our method makes strides towards capturing this underlying knowledge of human performance by integrating a model for the arm based on dynamics and containing a control system. We hypothesize that by embedding the human performance knowledge into the processing of arm movements, it will lead to better recognition performance. We present details for the design of our filter, our analysis of the filter from both expert-user and multiple-user pilot studies. Our results show that the filter has a positive impact on the recognition performance for arm gestures