Determination of tip transfer function for quantitative MFM using frequency domain filtering and least squares method

Magnetic force microscopy has unsurpassed capabilities in analysis of nanoscale and microscale magnetic samples and devices. Similar to other Scanning Probe Microscopy techniques, quantitative analysis remains a challenge. Despite large theoretical and practical progress in this area, present methods are seldom used due to their complexity and lack of systematic understanding of related uncertainties and recommended best practice. Use of the Tip Transfer Function (TTF) is a key concept in making Magnetic Force Microscopy measurements quantitative. We present a numerical study of several aspects of TTF reconstruction using multilayer samples with perpendicular magnetisation. We address the choice of numerical approach, impact of non-periodicity and windowing, suitable conventions for data normalisation and units, criteria for choice of regularisation parameter and experimental effects observed in real measurements. We present a simple regularisation parameter selection method based on TTF width and verify this approach via numerical experiments. Examples of TTF estimation are shown on both 2D and 3D experimental datasets. We give recommendations on best practices for robust TTF estimation, including the choice of windowing function, measurement strategy and dealing with experimental error sources. A method for synthetic MFM data generation, suitable for large scale numerical experiments is also presented

Specificity of Author’s Modality and Representation of Russia’s Image in Claudia Erdheim’s Book “Früher war alles besser”: an Austrian View

The reception of a foreign cultural (Russian) code by the European (Austrian) literary consciousness on the problematic, stylistic and lexical levels are studied in the article. The main trend characteristic for the representation of the image of Russia in the book by Claudia Erdheim is revealed: a retrospective look into the “bright past”. It is emphasized that the refrain phrase “Früher war alles besser” in the title has a symbolic meaning. Five mini-stories were analyzed. Attention is paid to the stereotypes of the Russian mass consciousness. Political stereotypes, ethical canons are studied in the perception of the author-narrator. It is argued that the antinomy of the Western way of thinking and the Russian mentality is the prevailing motive in the work under study. It is proved that the problem of the Russian-Austrian cultural dialogue is realized through the prism of the fundamental components of the Austrian mentality Einfühlung (feeling) and Gemütlichkeit (comfort, tranquility). Among the mental clichés of the narrator, stereotyped ideas about the Russian character (“broad soul”, “Russian scope”, “Russian maybe”, “longing”) are found. The book by K. Erdheim is a vivid example of the representation of the “Other” / “Alien” ideas about the “Other” national character and recreates the image of the Russian people in its artistic system

OPPORTUNITIES OF USE OF THE BIOFEEDBACK METHOD IN REHABILITATION OF PATIENTS WITH OCCUPATIONAL DISEASES CAUSED BY CHEMICAL AND PHYSICAL FACTORS

The article shows the opportunity of use of biomonitoring in patients with exogenous toxic encephalopathy in the remote period of chronic mercury intoxication. (CMI) and with, vibration disease caused by local vibration. The efficiency of the biofeedback method was assessed on the basis of the data of electroencephalography, auditory, visual and somatosensoric generated potentials, electroneuromyography, thermometry, dosed cold test and. rheography. Biofeedback training in people with. CMI caused decrease of total brain changes in EEG, improvement of amplitude indices at of the brain generated potentials, in people with vibration disease it caused decrease of manifestation of angiodistonic syndrome and. restoration of neuromuscular conductivity

Natural chain-breaking antioxidants and their synthetic analogs as modulators of oxidative stress

Oxidative stress is associated with the increased production of reactive oxygen species or with a significant decrease in the effectiveness of antioxidant enzymes and nonenzymatic defense. The penetration of oxygen and free radicals in the hydrophobic interior of biological membranes initiates radical disintegration of the hydrocarbon “tails” of the lipids. This process is known as “lipid peroxidation”, and the accumulation of the oxidation products as peroxides and the alde-hydes and acids derived from them are often used as a measure of oxidative stress levels. In total, 40 phenolic antioxidants were selected for a comparative study and analysis of their chain-breaking antioxidant activity, and thus as modulators of oxidative stress. This included natural and natural-like ortho-methoxy and ortho-hydroxy phenols, nine of them newly synthesized. Applied experimental and theoretical methods (bulk lipid autoxidation, chemiluminescence, in silico methods such as density functional theory (DFT) and quantitative structure–activity relationship ((Q)SAR) modeling) were used to clarify their structure–activity relationship. Kinetics of non-inhibited and inhibited lipid oxidation in close connection with inhibitor transformation under oxidative stress is considered. Special attention has been paid to chemical reactions resulting in the initiation of free radicals, a key stage of oxidative stress. Effects of substituents in the side chains and in the phenolic ring of hydroxylated phenols and biphenols, and the concentration were discussed

European Research on Magnetic Nanoparticles for Biomedical Applications: Standardisation Aspects

Magnetic nanoparticles have many applications in biomedicine and other technical areas. Despite their huge economic impact, there are no standardised procedures available to measure their basic magnetic properties. The International Organization for Standardization is working on a series of documents on the definition of characteristics of magnetic nanomaterials. We review previous and ongoing European research projects on characteristics of magnetic nanoparticles and present results of an online survey among European researchers

A reduced-reference perceptual image and video quality metric based on edge preservation

In image and video compression and transmission, it is important to rely on an objective image/video quality metric which accurately represents the subjective quality of processed images and video sequences. In some scenarios, it is also important to evaluate the quality of the received video sequence with minimal reference to the transmitted one. For instance, for quality improvement of video transmission through closed-loop optimisation, the video quality measure can be evaluated at the receiver and provided as feedback information to the system controller. The original image/video sequence-prior to compression and transmission-is not usually available at the receiver side, and it is important to rely at the receiver side on an objective video quality metric that does not need reference or needs minimal reference to the original video sequence. The observation that the human eye is very sensitive to edge and contour information of an image underpins the proposal of our reduced reference (RR) quality metric, which compares edge information between the distorted and the original image. Results highlight that the metric correlates well with subjective observations, also in comparison with commonly used full-reference metrics and with a state-of-the-art RR metric. © 2012 Martini et al

Round robin comparison on quantitative nanometer scale magnetic field measurements by magnetic force microscopy

Magnetic force microscopy (MFM) can be considered as a standard tool for nano-scale investigation of magnetic domain structures by probing the local stray magnetic field landscape of the measured sample. However, this generally provides only qualitative data. To quantify the stray magnetic fields, the MFM system must be calibrated. To that end, a transfer function (TF) approach was proposed, that, unlike point probe models, fully considers the finite extent of the MFM tip. However, albeit being comprehensive, the TF approach is not yet well established, mainly due to the ambiguities concerning the input parameters and the measurement procedure. Additionally, the calibration process represents an ill-posed problem which requires a regularization that introduces further parameters. In this paper we propose a guideline for quantitative stray field measurements by standard MFM tools in ambient conditions. All steps of the measurement and calibration procedure are detailed, including reference sample and sample under test (SUT) measurements and the data analysis. The suitability of the reference sample used in the present work for calibrated measurements on a sub-micron scale is discussed. A specific regularization approach based on a Pseudo-Wiener Filter is applied and combined with criteria for the numerical determination of a unique regularization parameter. To demonstrate the robustness of such a defined approach, a round robin comparison of magnetic field measurements was conducted by four laboratories. The guideline, the reference sample and the results of the round robin are discussed