Search results for "element"
showing 10 items of 13601 documents
Analysis of piezoelectric active patches performances by boundary element techniques
2008
This paper presents the analysis of active piezoelectric patches for cracked structures by Boundary Element Method. A two dimensional boundary integral formulation based on the multidomain technique is used to model cracks and to assemble the multi-layered piezoelectric patches to the host damaged structures. The fracture mechanics behavior of the repaired structures is analyzed for both perfect and imperfect interface between patches and host beams. The imperfect interface, representing the adhesive between two different layers, is modeled by using a “Spring Model” that involves linear relationships between the interface tractions, in normal and tangential directions, and the respective di…
Application of LA-ICP-MS as a rapid tool for analysis of elemental impurities in active pharmaceutical ingredients.
2014
The control of inorganic contaminants in active pharmaceutical ingredients has a significant role in the quality control of drug products. The concentration limits for metal residues in drug products have been defined by various regulatory guidelines. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) is a powerful and fast analytical technique for multi-elemental analysis. A disadvantage in using LA-ICP-MS method is the lack of matrix reference materials for validation and calibration purposes. This article focuses on the handling strategy of laboratory-made matrix calibration standards for the quantification of elemental impurities in an active pharmaceutical ingredie…
Low repetition rate gain-switched double-clad thulium-doped fiber laser operating in the 2 µm wavelength region
2021
Abstract The experimental demonstration of a gain-switched pulsed fiber laser with low repetition rate emission in the 2 µm wavelength region is presented. The laser cavity is based on the figure-9 shape, where the gain-switched operation of the laser is obtained by using a double-clad Tm-doped fiber (DCTDF) as gain medium and a commercial pulsed laser diode at 793-nm with configurable parameters as pump source. The pulse parameters of the pump source are optimized for efficient suppressing of unstable gain-switched laser oscillations. As a result, laser pulses with low repetition rate in a range from 10 to 20 kHz with laser emission at the wavelength of 1951 nm are obtained. The generated …
A Series of Ultra-Efficient Blue Borane Fluorophores
2020
13 pags., 14 figs., 5 tabs.
Contra la patologización intensiva en términos de derechos humanos: Activismo gordo en Argentina
2020
This work addresses the way in which Argentine Fat Activism has developed, in recent years, the demand for depathologization of fatness, taking elements from critical discourses on the health of fat people to frame them in a perspective typical of the Human Rights. First, the contemporary fat body is described in terms of stigma and discrimination, especially in the health field. Then, they refer to a series of critical positions on the pathologization and medicalization of fatness from the biomedical perspective, Fat Studies and Fat Activism. Lastly, a series of interventions that the Argentine activist collective Taller Hacer la Vista Gorda produced between 2017 and 2020 were considered, …
Novel solutions for closed-loop Reverse Electrodialysis: thermodynamic characterisation and perspective analysis
2019
Abstract Closed-loop Reverse Electrodialysis is a novel technology to directly convert low-grade heat into electricity. It consists of a reverse electrodialysis (RED) unit where electricity is produced exploiting the salinity gradient between two salt-water solutions, coupled with a regeneration unit where waste-heat is used to treat the solutions exiting from the RED unit and restore their initial composition. One of the most important advantages of closed-loop systems compared to the open systems is the possibility to select ad-hoc salt solutions to achieve high efficiencies. Therefore, the properties of the salt solutions are essential to assess the performance of the energy generation a…
Child specific activation in left auditory cortex predicts behavioral performance in inhibition tasks
2020
Sensory processing during development is important for the emerging cognitive skills underlying goal-directed behavior. Yet, it is not known how auditory processing in children is related to their cognitive functions. Here, we utilized combined magneto- and electroencephalographic (M/EEG) measurements to show that child-unique auditory cortical activity at ∼250 ms after auditory stimulation predicts the performance in inhibition tasks. While unaffected by task demands, the amplitude of the left-hemisphere activation pattern was significantly correlated with the variability of behavioral response time. Since this activation pattern is not present in adults, our results suggest divergent brai…
Die Synthese vono-Acylamino-β-dimethylamino-propiophenonen. 4. Mitt.: Synthese der primären Mannich-Basen
1972
Das durch Umsetzung von 2-Acetamino-β-dimethylamino-propiophenon (IVb) mit Dibenzylamin darstellbare 2-Acetamino-β-dibenzylamino-propiophenon (XXVII) kann hydrogenolytisch mit tels Palladium-Aktivkohle in die entsprechende, nur am aromatischen Stickstoff acetylierte primare Mannich-Base ubergefuhrt werden. In analoger Weise sind auch in 5-Stellung substituierte Derivate des 2-Acetamino-β-amino-propiophenons (XXVIII) zuganglich. Synthesis of 2-Acylamino-β-amino-propiophenones 2-Acetamino-β-dibenzylamino-propiophenone (XXVII) and its derivatives, substituted in 5-position, can be synthetized by reaction of 2-acetamino-β-dimethylamino-propiophenone (IVb) with dibenzylamine. By hydrogenolysis i…
Hierarchical adaptive cross approximation GMRES technique for solution of acoustic problems using the boundary element method
2009
In this paper a new Rapid Acoustic Boundary Element Method (RABEM) is presented using a Hierarchical GMRES solver for 3D acoustic problems. The Adaptive Cross Approximation is used to generate both the system matrix and the right hand side vector. The ACA is also used to evaluate the potential and the particle velocity values at selected internal points. Two different GMRES solution strategies (without preconditioner and with a block diagonal preconditioner) are developed and tested for low and high frequency problems. Implementation of different boundary conditions (i.e. Dirichlet, Neumann and mixed Robin) is also described. The applications presented include the problem of noise acting on…
Is lithium implicated in tobacco addiction?
2016
IntroductionTobacco is a source of mineral elements that can affect human health in various ways, such as lithium, which is used as a psychiatric medication. Lithium salts are used as mood-stabilizing drugs and indicated in the treatment of manic-depressive psychosis.ObjectiveStudying the lithium content in tobacco over the smokers’plasma content and evaluate the potential role of lithium in tobacco addiction.MethodsA total of 18 different tobacco products (cigarettes, smokeless and water pipe tobacco) and 125 plasma samples (45 from smokers, 10 from ex-smokers and 70 from non-smokers) were collected to determinate the lithium content. Tobacco samples were digested with nitric acid and lith…