390 research outputs found

    Discrepancy between Parents and Children in Reporting of Distress and Impairment: Association with Critical Symptoms

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    Background: We examined discrepant parent–child reports of subjective distress and psychosocial impairment. Method: Parent–child pairs (N = 112 pairs) completed the Health Dynamics Inventory at intake for outpatient therapy. Results: Average parent scores were significantly higher than average child scores on distress, impairment, and externalizing symptoms, but not internalizing symptoms. There were significant associations between parent–child discrepancy (i.e. children who reported greater distress or impairment than parents or vice versa) and child endorsement of several notable symptoms (rapid mood swings, panic, nightmares, and suicidal ideation). Conclusion: Parents tended to report more externalizing symptoms, distress, and impairment than children reported; however, when children report more distress and impairment than parents, this may indicate serious psychological problems

    Local deformations and chemical bonding in Fe-X (X = Si, Al, Ga, Ge) soft magnetic alloys

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    Dilute alloys based on ferromagnetic bcc iron modified by 3p (Al, Si) and 4p (Ga, Ge) elements are studied using the methods of the density-functional theory. It is shown that the local deformations and solution energies depend on the position of an alloying element in the periodic system. The nature of Fe-X chemical bonding varies from weak metallic in Fe-Ga to strong quasi-covalent in Fe-Si, which determines the values of local deformations in these alloys. The formation of pairs of impurity atoms in the position of the next-nearest neighbors leads to tetragonal lattice deformations, the value of which is highest for Si and Ge. The role of local deformations in the formation of unusual magnetic properties of Fe-X alloys is discussed. © 2013 Pleiades Publishing, Ltd

    Detection of white dwarf spin period variability in the intermediate polar V2306 Cygni

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    Magnetic cataclysmic variables are close binaries which consist of a compact object - a white dwarf - and a red dwarf filling its Roche Lobe. Such systems are physical laboratories which enable study of the influence of magnetic fields on matter flows. They often exhibit spin-up or spin-down of the white dwarf, while some systems exhibit more complex behaviour of the spin period change. We monitor changes of the spin periods of white dwarfs in a sample of close binary systems to study interaction of the magnetic field and accretion processes as well as evolution of intermediate polars. Within the framework of our intermediate polar monitoring program, we obtained photometric CCD observations at several observatories. Two-period trigonometric polynomial fitting was used for determination of extrema timings. The (O-C) analysis was performed to study the variability of the orbital and spin periods of the systems. Using data taken during 9 years of observations of the magnetic cataclysmic variable V2306 Cygni (formerly known as 1WGA J1958.2+3232), we detected the spin period variability which shows a spin-up of the white dwarf with a characteristic time of (53±5)104(53\pm5)\cdot10^4 years. The value of the spin period was 733.33976733.33976 seconds with the formal accuracy of 0.000150.00015 seconds. We derived an improved value of the orbital period of the system to be 4.371523±0.0000094.371523\pm0.000009 hours.Comment: Accepted to MNRAS 2019 July 23. 5 pages, 3 figures, supporting data onlin

    Measurement and comparison of energy of mechanical vibrations absorbed by humans

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    Human body responds to mechanical vibrations differently. Vibrations cause various types of damage to human organism. There are two main types of effects: short-term and longterm ones. The former cause tiredness, drowsiness and focus loss. While the latter induce mechanical damage to the individual organs such as skeleton, joints, nervous system. Influence of mechanical vibrations on human body is assessed by different parameters including amplitude, frequency, duration of action, acceleration etc. The next evaluation parameter might be energy. This article reports on the laboratory measurements of absorption of mechanical vibrations by humans. From our perspective, the short-time damage to human is mainly caused by absorption of vibrational energy and long-term damage - by mechanical vibration itself. A bio-dynamic system represents human body located in an automobile seat. The source of vibrations simulates car body movements generated during driving. The energy is measured in several levels because of the description of energy flow system. The primary aim is to determinate the level of the vibrational energy that enters into a human body and is subsequently absorbed. This is considered in terms of level and spectrum of input mechanical vibrations. Based on the findings, it is possible to evaluate the level of absorbed energy and compare for the sample of population

    Effect of magnetism on the solution energy of 3p (Al, Si) and 4p (Ga, Ge) elements in iron

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    The method based on the density-functional theory has been used to study the solubility of 3p (Al, Si) and 4p (Ga, Ge) elements in ferromagnetic and paramagnetic states of bcc iron. To simulate the paramagnetic state, two different approaches have been employed, which were implemented using the SIESTA and LSGF packages. It has been established that the solution energy of all these impurities decreases upon the transition into the paramagnetic state. The solution energies obtained by averaging over the ensemble of unpolarized magnetic configurations agree well with the values obtained in the coherentpotential approximation. At the same time, the allowance for the magnetic polarization in the vicinity of an impurity leads to a decrease in the solution energy, which is most clearly pronounced at temperatures close to TC. The temperature dependence of the solution energies of the impurities in the paramagnetic state is discussed. © Pleiades Publishing, Ltd., 2013

    Sol-gel Synthesis, Photo- and Electrocatalytic Properties of Mesoporous TiO2 Modified with Transition Metal Ions

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    Abstract Mesoporous nanosized titania films modified with Co2+, Ni2+, Mn3+, and Cu2+ ions have been produced by templated sol-gel method and characterized by optical spectroscopy, X-ray diffraction (XRD), and Brunauer, Emmett, and Teller (BET) surface area measurement. Band gap energy and the position of flat band potentials were estimated by photoelectrochemical measurements. The films doped with transition metals possessed higher photocurrent quantum yield, as well as photo- and electrochemical activity compared to undoped samples. Mn+/TiO2 (M–Co, Ni, Mn, Cu) electrodes with low dopant content demonstrate high efficiency in electrocatalytic reduction of dissolved oxygen. Polarization curves of TiO2, TiO2/Ni2+, TiO2/Co2+/3+, and TiO2/Mn3+ electrodes contain only one current wave (oxygen reduction current). It means that reaction proceeds without the formation of an intermediate product H2O2

    Fate of sulphate removed during the treatment of circumneutral mine water and acid mine drainage with coal fly ash: Modelling and experimental approach

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    The treatment of acid mine drainage (AMD) and circumneutral mine water (CMW) with South African coal fly ash (FA) provides a low cost and alternative technique for treating mine wastes waters. The sulphate concentration in AMD can be reduced significantly when AMD was treated with the FA to pH 9. On the other hand an insignificant amount of sulphate was removed when CMW (containing a very low concentration of Fe and Al) was treated using FA to pH 9. The levels of Fe and Al, and the final solution pH in the AMD–fly ash mixture played a significant role on the level of sulphate removal in contrast to CMW–fly ash mixtures. In this study, a modelling approach using PHREEQC geochemical modelling software was combined with AMD–fly ash and/or CMW–fly ash neutralization experiments in order to predict the mineral phases involved in sulphate removal. The effects of solution pH and Fe and Al concentration in mine water on sulphate were also investigated. The results obtained showed that sulphate, Fe, Al, Mg and Mn removal from AMD and/or CMW with fly ash is a function of solution pH. The presence of Fe and Al in AMD exhibited buffering characteristic leading to more lime leaching from FA into mine water, hence increasing the concentration of Ca2+. This resulted in increased removal of sulphate as CaSO4·2H2O. In addition the sulphate removal was enhanced through the precipitation as Fe and Al oxyhydroxysulphates (as shown by geochemical modelling) in AMD–fly ash system. The low concentration of Fe and Al in CMW resulted in sulphate removal depending mainly on CaSO4·2H2O. The results of this study would have implications on the design of treatment methods relevant for different mine waters.Web of Scienc
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