Search results for "Mg"
showing 10 items of 492 documents
A photoelectrochemical investigation of conversion coatings on Mg substrates
2005
Abstract The structure, morphology and composition of conversion coatings grown in stannate bath on pure Mg were studied using potential–time, polarization curves, X-ray diffraction, scanning electron microscopy and photocurrent spectroscopy. The coating is manly constituted by crystalline magnesium–tin hydroxide, whose morphology and distribution depends on the conversion bath composition and temperature. The photoelectrochemical investigation allowed to estimate the band gap value of MgSn(OH) 6 and flat band potential. A sketch of the metal/passive film/electrolyte junction formed during conversion on the metal substrate is reported to account for the overall photoelectrochemical behaviou…
Enhanced optical properties of Cd–Mg-co-doped ZnO nanoparticles induced by low crystal structure distortion
2020
Abstract The growth of CdxMg0.125-xZn0.875O nanoparticles with yellow-orange luminescence is achieved up to 2.5 at. % Cd via a modified sol–gel process. X-ray diffraction analysis confirmed that all the nanoparticles have the hexagonal wurtzite structure. It is found that Cd doping has a considerable effect on the crystal size, microstrain, band gap, and photoluminescence of the Mg0·125Zn0·875O structure, originating from a preferred crystallographic orientation along the (101) plane of the wurtzite structure. The shift and broadening of the E2(high) mode observed in the Raman spectra due to growth-induced strain corroborates the small distortion observed in the X-ray diffraction data. The …
Luminescence Properties and Decay Kinetics of Mn2+ and Eu3+ Co-Dopant Ions In MgGa2O4 Ceramics
2018
A. Luchechko gratefully acknowledges a grant from the Institute of Physics PAS for a research visit to the institute, while A.I. Popov has been supported by project LZP-2018/1-0214 from the Latvian Council of Science.
Limiting neutrino magnetic moments with Borexino Phase-II solar neutrino data
2017
A search for the solar neutrino effective magnetic moment has been performed using data from 1291.5 days exposure during the second phase of the Borexino experiment. No significant deviations from the expected shape of the electron recoil spectrum from solar neutrinos have been found, and a new upper limit on the effective neutrino magnetic moment of $\mu_{\nu}^{eff}$ $<$ 2.8$\cdot$10$^{-11}$ $\mu_{B}$ at 90\% c.l. has been set using constraints on the sum of the solar neutrino fluxes implied by the radiochemical gallium experiments.Using the limit for the effective neutrino moment, new limits for the magnetic moments of the neutrino flavor states, and for the elements of the neutrino magne…
On a class of singular measures satisfying a strong annular decay condition
2018
A metric measure space $(X,d,\mu)$ is said to satisfy the strong annular decay condition if there is a constant $C>0$ such that $$ \mu\big(B(x,R)\setminus B(x,r)\big)\leq C\, \frac{R-r}{R}\, \mu (B(x,R)) $$ for each $x\in X$ and all $0<r \leq R$. If $d_{\infty}$ is the distance induced by the $\infty$-norm in $\mathbb{R}^N$, we construct examples of singular measures $\mu$ on $\mathbb{R}^N$ such that $(\mathbb{R}^N, d_{\infty},\mu)$ satisfies the strong annular decay condition.
Magnetic field control of the spin Seebeck effect
2015
The origin of the suppression of the longitudinal spin Seebeck effect by applied magnetic fields is studied. We perform numerical simulations of the stochastic Landau-Lifshitz-Gilbert equation of motion for an atomistic spin model and calculate the magnon accumulation in linear temperature gradients for different strengths of applied magnetic fields and different length scales of the temperature gradient. We observe a decrease of the magnon accumulation with increasing magnetic field and we reveal that the origin of this effect is a field dependent change of the frequency distribution of the propagating magnons. With increasing field the magnonic spin currents are reduced due to a suppressi…
Relaxation of periodic and nonstandard growth integrals by means of two-scale convergence
2019
An integral representation result is obtained for the variational limit of the family functionals $\int_{\Omega}f\left(\frac{x}{\varepsilon}, Du\right)dx$, as $\varepsilon \to 0$, when the integrand $f = f (x,v)$ is a Carath\'eodory function, periodic in $x$, convex in $v$ and with nonstandard growth.
Regularity properties for quasiminimizers of a $(p,q)$-Dirichlet integral
2021
Using a variational approach we study interior regularity for quasiminimizers of a $(p,q)$-Dirichlet integral, as well as regularity results up to the boundary, in the setting of a metric space equipped with a doubling measure and supporting a Poincar\'{e} inequality. For the interior regularity, we use De Giorgi type conditions to show that quasiminimizers are locally H\"{o}lder continuous and they satisfy Harnack inequality, the strong maximum principle, and Liouville's Theorem. Furthermore, we give a pointwise estimate near a boundary point, as well as a sufficient condition for H\"older continuity and a Wiener type regularity condition for continuity up to the boundary. Finally, we cons…
Gill ATPase activity in Procambarus clarkii as an indicator of heavy metal pollution.
1989
Lake Albufera and the surrounding rice field waters are subjected to very heavy loads of sewage and toxic industrial residues, including heavy metals, from the many urban and waste waters of this area. The American red crayfish, Procambarus clarkii have a high resistance to toxic effects of heavy metals. The sublethal effects of heavy metals on gills of fish and aquatic invertebrates have been extensively studied. Some metabolic disturbances and histologic damages have been reported, as well as osmoregulation alterations. However, little work has been done about the effect of heavy metals on Na,K and Mg-ATPases of freshwater invertebrate gills. Na,K-ATPase is the prime mediator of ion trans…
Cationic polyaspartamide-based nanocomplexes mediate siRNA entry and down-regulation of the pro-inflammatory mediator high mobility group box 1 in ai…
2015
Abstract High-mobility group box 1 (HMGB1) is a nonhistone protein secreted by airway epithelial cells in hyperinflammatory diseases such as asthma. In order to down-regulate HMGB1 expression in airway epithelial cells, siRNA directed against HMGB1 was delivered through nanocomplexes based on a cationic copolymer of poly(N-2-hydroxyethyl)- d,l -aspartamide (PHEA) by using H441 cells. Two copolymers were used in these experiments bearing respectively spermine side chains (PHEA-Spm) and both spermine and PEG2000 chains (PHEA-PEG-Spm). PHEA-Spm and PHEA-PEG-Spm derivatives complexed dsDNA oligonucleotides with a w/w ratio of 1 and higher as shown by a gel retardation assay. PHEA-Spm and PHEA-P…