Nonlinear magnetic vortex dynamics in a circular nanodot excited by spin-polarized current

We investigate analytically and numerically nonlinear vortex spin torque oscillator dynamics in a circular magnetic nanodot induced by a spin-polarized current perpendicular to the dot plane. We use a generalized nonlinear Thiele equation including spin-torque term by Slonczewski for describing the nanosize vortex core transient and steady orbit motions and analyze nonlinear contributions to all forces in this equation. Blue shift of the nano-oscillator frequency increasing the current is explained by a combination of the exchange, magnetostatic, and Zeeman energy contributions to the frequency nonlinear coefficient. Applicability and limitations of the standard nonlinear nano-oscillator model are discussed.     

Ex Vivo and In Vitro Antiaging and Antioxidant Extract Activity of the Amelanchier ovalis from Siberia

Phenolic acids are biologically active substances that prevent aging and age-related diseases, e.g., cancer, cardiovascular diseases, Alzheimer’s disease, Parkinson’s disease, etc. Cellular senescence is related to oxidative stress. The Siberian Federal District is rich in medicinal plants whose extracts contain phenolic acids. These plants can serve as raw materials for antiaging, antioxidant food supplements, and Amelanchier ovalis is one of them. In the present research, we tested the phytochemical profile of its extract for phenolic acids. Its geroprotective and antioxidant properties were studied both ex vivo and in vitro using Saccharomyces cerevisiae Y-564 as a model organism. The chromotographic analysis revealed gallic, p-hydroxybenzoic, and protocatechuic acids, as well as derivatives of chlorogenic and gallic acids. The research involved 0.25, 0.5, and 1.0 mg/mL extracts of Amelanchier ovalis, all of which increased the growth and lifespan of yeast cells. In addition, the extracts increased the survival rate of yeast under oxidative stress. An in vitro experiment also demonstrated the antioxidant potential of Amelanchier ovalis against ABTS radicals. Therefore, the Amelanchier ovalis berry extract proved to be an excellent source of phenolic acids and may be recommended as a raw material for use in antioxidant and geroprotective food supplements.     

Ultrasonic mineralization of a reactive textile azo dye, remazol black B

The degradation of a reactive black dye in oxygen saturated aqueous solution has been investigated using a high frequency ultrasonic generator. The ˙OH radical initiated oxidative degradation of the dye results in 65% mineralization as measured by the decrease in the total organic content. Ion chromatography indicates that the only remaining components are oxalate, sulfate and nitrate ions.     

Antimicrobial properties and thermal stability of polycarbonate modified with 1‐alkyl‐3‐methylimidazolium tetrafluoroborate ionic liquids

Four water immiscible ionic liquids (ILs): 1‐hexyl‐3‐methylimidazolium tetrafluoroborate, 1‐heptyl‐3‐methylimidazolium tetrafluoroborate, 1‐octyl‐3‐methylimidazolium tetrafluoroborate and 1‐dodecyl‐3‐methylimidazolium tetrafluoroborate have been synthesized. Polycarbonate (PC) films containing ILs were prepared by solvent casting from methylene chloride solutions. Scanning electron microscopy measurements showed the high homogeneity of PC/IL films with the IL content up to 4 wt %. The tendency to IL aggregation was observed for polymeric films with higher IL content (5%). PC/IL composites were found to have the reduced thermal decomposition temperature under both an air and a nitrogen atmosphere in comparison with the neat PC. The effect of IL content on the antimicrobial activity of PC films against Escherichia coli bacteria was studied. Pronounced antimicrobial efficacy was revealed for PC/IL films for all studied ILs starting from 3 wt % of IL. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40050.     

Designing a performance measurement system to support materials management in engineer-to-order:a case study

There are many different production situations that can be employed to meet demand.In the engineer-toorder(ETO)production situation,products are manufactured to meet specific customer needs by unique engineering or significant customization.In such an environment,failing to supply the required materials in the right quantities and at the right time increases the risk of breaching due date agreements and thereby losing customer satisfaction.As such,materials management is one of the most important and critical processes within production planning and control in ETO.To bring attention and improvement to this area,ETO companies may benefit from a performance measurement system(PMS)that systematically monitors how well materials management is carded out.The design of a company's PMS varies with its production situation.Within the large body of literature on performance management and measurement,limited literature specifically addressing performance measurement in ETO has been identified.After being approached by a Norwegian ETO company requesting a PMS for materials management,the authors therefore set out to design the PMS from scratch,using literature on ETO,materials management and performance management and measurement as a starting point.The paper presents the proposed PMS.It provides a basis for further studies on the topic,and could be used by managers in ETO companies to assess and improve their materials management practice.     

Geomorphological process development under the impact of man-made reservoir operation,a case study: Bratsk reservoir,Baikal-Angara hydroengineering system,Russia

Bulletin of Engineering Geology and the Environment - The Bratsk reservoir is one of the constituents of the Baikal-Angara hydroengineering system. Large hydropower reservoirs created worldwide...     

Virtual unrolling and information recovery from scanned scrolled historical documents

The objective of our work is to enable the reading of fragile scrolled historical parchments without the need to physically unravel them, thus providing valuable information to a wide range of scholarly disciplines. This problem has not been investigated by the computer vision community properly yet due to the need for parchment scanning technology: standard X-ray equipment is not sufficient as there is a requirement to extract out parchment ink in addition to the parchment's underlying structure. Effective data recovery is also compromised as content from historical scrolled documents is inaccessible due to the deterioration of the parchment. We create a 3D volumetric model of a scrolled parchment's underlying geometry and perform digital unwrapping of the parchment, producing a readable image of the text as an output. The proposed recovery framework consists of structure preserving anisotropic filtering in combination with robust segmentation, surface modelling and ink projection. We demonstrate with real examples how our algorithm is able to recover the underlying text and to solve the major challenge for scrolled parchment analysis, namely segmentation of connected layers and processing the data without user interaction.     

Unique direct synthesis of cyanide-bridged Fe2Cu2 molecular squares by destruction of sodium nitroprusside

The one-pot reaction of copper powder, sodium nitroprusside, ammonium thiocyanate and 2,2′-bipyridine (bpy) in acetonitrile solution at ambient conditions of air and water yields the novel heterometallic [Fe₂Cu₂(bpy)₆(μ-CN)₄(NCS)₂]₂[Fe(CN)₅(NO)](NCS)₂·5H₂O complex 1, which has been structurally and magnetically characterized. The most prominent feature of this complex is the unique tetranuclear squares comprised [Cu(bpy)NCS]⁺ and [Fe(bpy)₂]²⁺ corners with CN edges. The CuCu and FeFe separations are 6.72 and 7.73 Å, respectively. The variable-temperature magnetic susceptibility study revealed that a very weak antiferromagnetic coupling is active between Cu(II) centers (J_CuCu = −0.37 cm⁻¹).