Search results for "ABL"
showing 10 items of 13111 documents
The effects of environment on Arctica islandica shell formation and architecture
2017
Mollusks record valuable information in their hard parts that reflect ambient environmental conditions. For this reason, shells can serve as excellent archives to reconstruct past climate and environmental variability. However, animal physiology and biomineralization, which are often poorly un- derstood, can make the decoding of environmental signals a challenging task. Many of the routinely used shell-based proxies are sensitive to multiple different environmental and physiological variables. Therefore, the identification and in- terpretation of individual environmental signals (e.g., water temperature) often is particularly difficult. Additional prox- ies not influenced by multiple enviro…
Hard cap espresso extraction and liquid chromatography determination of bioactive compounds in vegetables and spices
2017
Abstract A new analytical procedure, based on liquid chromatography with diode array and fluorescence detection, has been proposed for the determination of bioactive compounds in vegetables and spices after hard cap espresso extraction. This novel extraction system has been tested for the determination of capsaicin and dihydrocapsaicin from fresh chilli and sweet pepper, piperine from ground pepper, curcumin from turmeric and curry, and myristicin from nutmeg. Extraction efficiency was evaluated by using acetonitrile:water and ethanol:water mixtures. The proposed method allows the extraction of samples with 100 mL of 60% (v/v) ethanol in water. The obtained limits of quantification for the …
On Whitham and Related Equations
2017
The aim of this paper is to study, via theoretical analysis and numerical simulations, the dynamics of Whitham and related equations. In particular, we establish rigorous bounds between solutions of the Whitham and Korteweg–de Vries equations and provide some insights into the dynamics of the Whitham equation in different regimes, some of them being outside the range of validity of the Whitham equation as a water waves model.
Structural characterization and electrochemical hydrogen storage properties of Ti2LxZrxNi (x [ 0, 0.1, 0.2) alloys prepared by mechanical alloying
2013
International audience; Nominal Ti2Ni was synthesized under argon atmosphere at room temperature using a planetary high-energy ball mill. The effect of milling time and Zr substitution for Ti on the microstructure was characterized by XRD, SEM and TEM, and the discharge capacities of Ti2xZrxNi (x 1/4 0, 0.1, 0.2) were examined by electrochemical measurements at galvanostatic conditions. XRD analysis shows that amorphous phase of Ti2Ni can be elaborated by 60 h of milling, whereas Zr substitution hinders amorphization process of the system. The products of ball milling nominal Ti2xZrxNi (x 1/4 0.1, 0.2) were austenitic (Ti, Zr)Ni and partly TiO, despite the fact that the operation was carrie…
Experimental investigation on different rainfall energy harvesting structures
2018
In this paper proposes an experimental comparison between different rainfall harvesting devices and the study of the corresponding electrical rectifying circuit. More in detail, three harvesting structures are considered: the cantilever, the bridge and the floating circle. For each of the proposed structure, different waveforms have been acquired and discussed. The processed data have been compared in order to suggest the best choice for the rectifying circuit, from the simplest one to the most endorsed in the technical literature.
FPGA based digital lock-in amplifier for fNIRS systems
2018
Lock-In Amplifiers (LIA) represent a powerful technique helping to improve signals detectability when low signal to noise ratios are experienced. Continuous Wave functional Near Infrared Spectroscopy (CW-fNIRS) systems for e-health applications usually suffer of poor detection due to the presence of strong attenuations of the optical recovering path and therefore small signals are severely dipped in a high noise floor. In this work a digital LIA system, implemented on a Zynq® Field Programmable Gate Array (FPGA), has been designed and tested to verify the quality of the developed solution, when applied in fNIRS systems. Experimental results have shown the goodness of the proposed solutions.
A half-metallic half-Heusler alloy having the largest atomic-like magnetic moment at optimized lattice constant
2016
For half-Heusler alloys, the general formula is XYZ, where X can be a transition or alkali metal element, Y is another transition metal element, typically Mn or Cr, and Z is a group IV element or a pnicitide. The atomic arrangements within a unit-cell show three configurations. Before this study, most of the predictions of half-metallic properties of half-Heusler alloys at the lattice constants differing from their optimized lattice constant. Based on the electropositivity of X and electronegativity of Z for half-Heusler alloys, we found that one of the configurations of LiCrS exhibits half-metallic properties at its optimized lattice constant of 5.803Å, and has the maximum atomic-like magn…
Maximum Torque Per Ampere control algorithm for low saliency ratio interior permanent magnet synchronous motors
2017
This paper presents an investigation on the comparison between the Maximum Torque Per Ampere (MTPA) and the Field Orientation Control (FOC) algorithms for interior permanent magnet synchronous machines (IPMSMs). In particular, this study was carried out on a small-power IPMSM with low salience ratio. Both control algorithms have been implemented in the Matlab/Simulink environment, obtaining promising results.
Pulsed Electro-Acoustic Method for specimens and cables employed in HVDC systems: Some feasibility considerations
2018
Recent experiments on the use of the PEA method for testing dielectric materials in specimens and comparison with a detailed model provide an insight of the phenomenon and suggest the need of adopting similar models also for cables. What is said is even more important considering the possible future adoption of the PEA methodology to test DC cables for Pre-Qualification and Type Tests. The use of an accurate model of the PEA cell used for testing specimens and related experiments prove that the thickness of the different parts composing the PEA setup is a basic element for providing accurate charge reading and interpretation of the phenomenon. Both simulation and experimental results, carri…
Structure and dielectric properties of Na0.5Bi0.5TiO3-CaTiO3 solid solutions
2016
Despite wide studies of Na0.5Bi0.5TiO3, structure of this material and its connection with the observed physical properties still raise numerous questions due to mutually contradicting results obtained. Here, structure and dielectric properties of poled and unpoled Na0.5Bi0.5TiO3-CaTiO3 solid solutions are studied, projecting the obtained concentration dependence of structure and dielectric properties on pure Na0.5Bi0.5TiO3 as the end member of this material group. X-ray diffraction patterns for Na0.5Bi0.5TiO3-CaTiO3 solid solutions reveal dominating of an orthorhombic Pnma phase, even for the compositions approaching the end composition (Na0.5Bi0.5TiO3), whereas structure of pure Na0.5Bi0.…