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Register a new userRevealing magnetic component in crystalline Fe-gluconate
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Low temperature Mossbauer spectroscopic and magnetization measurements were performed on a crystalline sample of Fe-gluconate. Fe atoms were revealed to exist in two phases i.e. a major (90-94 pct.) and a minor (6-10 pct.). Based on values of spectral parameters the former can be regarded as ferrous and the latter as ferric. A sub spectrum associated with the ferric phase shows a significant broadening below ca. 30 K corresponding to 7.5 kGs. A magnetic origin of the effect was confirmed by the magnetization measurements. Evidence on the effect of the magnetism on the lattice vibrations of Fe atoms in both components was found. The Debye temperature, T_D, associated with the vibrations of Fe2+ ions is by a factor of about 2 smaller in the temperature range below ca. 30 K than the one determined from the data measured above ca. 30 K. Interestingly, the T_D-value found for the Fe3+ ions from the data recorded below ca.30 K is about two times smaller than the corresponding value determined for the Fe2+ ions.
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Fe-gluconate, Fe(C_6H_11O_7_2xH_2O is a well-known material widely used for iron supplementation. On the other hand, it is used in food industry as a coloring agent, in cosmetic industry for skin and nail conditioning and metallurgy. Despite of wide range of applications its physical properties were not studied extensively. In this study, Fe-gluconate with three different amount of water viz. x=2 (fully hydrated, 0 < x < 2 (intermediate) and x=0 (dry) was investigated by means of X-ray diffraction (XRD) and Mossbauer spectroscopic (MS) methods. The former in the temperature range of 20-300 K, and the latter at 295 K. Based on the XRD measurements crystallographic structures were determined: monoclinic (space group I2) for the hydrated sample and triclinic (space group P1) for the dry sample. The partially hydrated sample was two-phased. Unit cells parameters for both structures show strong, very complex and non-monotonic temperature dependences. Mossbauer spectroscopic measurements gave evidence that iron in all samples exist in form of Fe(II) and Fe(III) ions. The amount of the latter equals to ca.30% in the hydrated sample and to ca.20% in the dry one.
Amorphous Fe-gluconate was studied by means of the X-ray diffraction and Mossbauer spectroscopy. Spectra measured in the temperature range between 78 and 295 K were analysed in terms of three doublets using a thin absorber approximation method. Two of the doublets were associated with the major Fe(II) phase (72%) and one with the minor Fe(III) phase (28%). Based on the obtained results the following quantities characteristic of lattice dynamical properties were determined: Debye temperature from the temperature dependence of the center shift and that of the spectral area (recoil-free factor), force constant, change of the kinetic and potential energies of vibrations. The lattice vibrations of Fe ions present in both ferrous and ferric phases are not perfectly harmonic, yet on average they are. Similarities and differences to the crystalline Fe-gluconate are also reported.
Inter-Component Communication (ICC) is a key mechanism in Android. It enables developers to compose rich functionalities and explore reuse within and across apps. Unfortunately, as reported by a large body of literature, ICC is rather complex and largely unconstrained, leaving room to a lack of precision in apps modeling. To address the challenge of tracking ICCs within apps, state of the art static approaches such as Epicc, IccTA and Amandroid have focused on the documented framework ICC methods (e.g., startActivity) to build their approaches. In this work we show that ICC models inferred in these state of the art tools may actually be incomplete: the framework provides other atypical ways of performing ICCs. To address this limitation in the state of the art, we propose RAICC a static approach for modeling new ICC links and thus boosting previous analysis tasks such as ICC vulnerability detection, privacy leaks detection, malware detection, etc. We have evaluated RAICC on 20 benchmark apps, demonstrating that it improves the precision and recall of uncovered leaks in state of the art tools. We have also performed a large empirical investigation showing that Atypical ICC methods are largely used in Android apps, although not necessarily for data transfer. We also show that RAICC increases the number of ICC links found by 61.6% on a dataset of real-world malicious apps, and that RAICC enables the detection of new ICC vulnerabilities.
Coherent two-dimensional spectroscopy in IR or visible region is very effective for studying correlations, energy relaxation/transfer pathways in complex multi-chromophore or multi-mode systems. However it is usually restricted up to two-quanta excitations and their properties. In this paper an arbitrary level of excitation is suggested as the utility to scan nonlinear potential surfaces of quantum systems up to a desired excitation degree. This can be achieved by a simple three-pulse laser spectroscopy approach. Accurate evaluation of high-level anharmonicities as well as transition amplitudes can be directly obtained. Additionally, questions regarding the quantum nature of the probed system can be addressed by studying absolute peak positions.
We investigated head-to-head domain walls in nanostrips of epitaxial $mathrm{Fe}_4mathrm{N}(001)$ thin films, displaying a fourfold magnetic anisotropy. Magnetic force microscopy and micromagnetic simulations show that the domain walls have specific properties, compared to soft magnetic materials. In particular, strips aligned along a hard axis of magnetization are wrapped by partial flux-closure concertina domains below a critical width, while progressively transforming to zigzag walls for wider strips. Transverse walls are favored upon initial application of a magnetic field transverse to the strip, while transformation to a vortex walls is favored upon motion under a longitudinal magnetic field. In all cases the magnetization texture of such fourfold anisotropy domain walls exhibits narrow micro-domain walls, which may give rise to peculiar spin-transfer features.
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