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Magnetic tape heads are ubiquitously used to read and record on magnetic tapes in technologies as diverse as old VHS tapes, modern hard-drive disks, or magnetic bands on credit cards. Their design highlights the ability to convert electric signals into fluctuations of the magnetic field at very high frequencies, which is essential for the high-density storage demanded nowadays. Here, we twist this conventional use of tape heads to implement one in a magnetic tweezers design, which offers the unique capability of changing the force with a bandwidth of ∼10 kHz. We calibrate our instrument by developing an analytical expression that predicts the magnetic force acting on a superparamagnetic bead based on the Karlqvist approximation of the magnetic field created by a tape head. This theory is validated by measuring the force dependence of protein L unfolding/folding step sizes and the folding properties of the R3 talin domain. We demonstrate the potential of our instrument by carrying out millisecond-long quenches to capture the formation of the ephemeral molten globule state in protein L, which has never been observed before. Our instrument provides the capability of interrogating individual molecules under fast-changing forces with a control and resolution below a fraction of a piconewton, opening a range of force spectroscopy protocols to study protein dynamics under force.

Alternating current (AC) copper losses in motors increase with carrier frequency of the pulse width modulation (PWM) and are further increased by leakage flux of the permanent magnet. Therefore, AC copper losses increase with motor speed. Conventional techniques for reducing AC copper losses tend to increase other losses. In this paper, AC copper loss was reduced by wrapping a magnetic tape made of a magnetic composite material around the winding. This method controlled the flux path through the winding. Magnetic composite materials are mixtures of magnetic powders and liquid resins whose magnetic properties can be manipulated by changing the combination and other factors. When Fe–Si–Al magnetic tape was wrapped around the winding, the AC copper loss was reduced by 40%. The loss was further reduced by optimizing the magnetic properties of the magnetic composite material. The AC copper loss was maximally reduced when the specific permeability was 100 and the saturation flux density was 1.6. Magnetic tapes composed of magnetic composite materials with high saturation flux density and specific permeability reduce the AC copper losses without increasing other losses in the motor.

In this study, we demonstrate a single-track magnetic code tape-based absolute position sensor system. Unlike traditional dual-track systems, our method simplifies manufacturing and avoids crosstalk between tracks, offering higher tolerance to alignment errors. The sensing system employs an array of magnetic field sensing elements that recognize the bit sequence encoded on the tape. This approach allows for accurate position determination even when the number of sensing elements is fewer than the number of bits covered, and without the need for specific spacing between sensing elements and bit length. We demonstrate the system’s ability to learn and adapt to various magnetic code patterns, including those that are irregular or have been altered. Our method can identify and localize the sensed magnetic field pattern directly within a self-learned magnetic field map, providing robust performance in diverse conditions. This self-adaptive capability enhances operational safety and reliability, as the system can continue functioning even when the magnetic tape is misaligned or has undergone changes.

Audio carriers are subject to a fast and irreversible decay. In order to save valuable historical recordings, the audio signal and other relevant information can be extracted from the source audio document and stored on another medium, normally a redundant digital storage system. This procedure is called ’content transfer’. It is a costly and time-consuming procedure. There are several solutions with which the cost can be reduced. One consists of picking up all tracks from a two-sided tape in one pass. This means that some tracks will be digitized forward and some backwards, to be subsequently corrected in the digital workstation. This article is concerned with the question of whether reading tracks backwards introduces unwanted effects into the signal. In particular, it investigates whether a difference can be observed between audio signals read forward or backwards and, if so, whether the difference is measurable. The results show that a difference can be observed, yet this is not enough to conclude that this “backwards” approach should not be used. The complexity of the situation is presented in the discussion. Future work includes reproducing this experiment with different audio equipment, as well as a perception test with human subjects.

A magnetic-tape locomotion mechanism of a wall-climbing robot is developed. A mathematical model of the motion of a mobile robot on vertical surfaces is proposed. The basic hierarchical elements of the mathematical model are considered. A method for automated formation of a set of differential equations for complex mechanical systems is developed. The motion stability of the mobile robot and the dependence of the capacity of drive motors on the locomotion speed are investigated.

Overview This guide aims to clarify the role of azimuth in audio tape playback, a crucial but sometimes overlooked practice in preserving magnetic audio tapes. By delving into the principles and mechanics of aligning head and tape azimuth, it shall serve as a supplement to the comprehensive introduction presented in the ARSC Guide to Audio Preservation and a companion to Guidelines on the Production and Preservation of Digital Audio Objects: IASA TC-04. It also acknowledges the varied expertise within the international audiovisual preservation community and is intended to be an accessible reference for those with a basic understanding of magnetic tape principles and the broader significance of audiovisual preservation. Within these pages, readers will find an in-depth explanation of azimuth--its significance, principles, and the tools essential for achieving the highest quality audio playback and transfers. Special thanks are extended to Richard L. Hess and Nicholas Bergh for their invaluable contributions to this topic through numerous papers, presentations, and workshops. As we collectively navigate the complexities of audiovisual stewardship and preservation, the ARSC Technical Committee hopes this guide will serve as a key technical reference for cultural heritage stewards, audio engineers, collectors, enthusiasts, and other professionals engaged with audio media.

The friction coefficient is an important parameter in designing magnetic tape transports. We have introduced a novel approach to reduce the friction coefficient between guides and magnetic tape by laser surface texturing the cylindrical guides. The surface features enhance the formation of an air bearing and hence reduce the friction coefficient.

The ICDD's Powder Diffraction File ™ (PDF ® ) is a database of inorganic and organic diffraction data used for phase identification and materials characterization by powder diffraction. The PDF has been available for over 75 years and finds application in X-ray, synchrotron, electron, and neutron diffraction analyses. With entries based on powder and single crystal data, the PDF is the only crystallographic database where every entry is editorially reviewed and marked with a quality mark that alerts the user to the reliability/quality of the submitted data. The editorial processes of ICDD's quality management system are unique in that they are ISO 9001:2015 certified. Initially offered as text on paper cards and books, the PDF evolved to a computer-readable database in the 1960s and today is both computer and web accessible. With data mining and phase identification software available in PDF products, and the databases’ compatibility with vendor (third party) software, the 1 000 000+ published PDF entries serve a wide range of disciplines covering academic, industrial, and government laboratories. Details describing the content of database entries are presented to enhance the use of the PDF.

In the recent years card frauds on a global level present a big challenge for the banks, card organizations, merchants and last but not least for the cardholders. The latter's trust in bank cards as a main electronic payment instrument has been severely compromised. Therefore preventing card fraud is of paramount importance to everyone. There are different means of counteraction available including: migration to chip cards according to EMV standard - those substitute the potentially vulnerable cards with a magnetic tape; for online transactions - systems for checking card security codes, applying 3-D Secure safety protocol; use of systems to identify fraud transactions and others. Currently intelligent methods are being very popular to prevent card fraud and those include techniques applying neural networks. Having the access to data of 400 000 card transactions made with 16 000 different bank cards over a period of six months, we have put into practice experiments to analyze data with intelligent methods. Through rule induction we have reached dependencies which are confirmed using the neural network Alyuda NeuroIntelligence. The most important characteristics of a payment card transaction, that ought to be closely monitored by banks in order to prevent fraud, are the currency and the time of the execution of the transaction (month, day and time). Those dependencies can be used effectively by the banks to identify suspicious and potentially fraudulent transactions.

All-optical magnetization reversal with femtosecond laser pulses facilitates the fastest and least dissipative magnetic recording, but writing magnetic bits with spatial resolution better than the wavelength of light has so far been seen as a major challenge. Here, we demonstrate that a single femtosecond laser pulse of wavelength 800 nm can be used to toggle the magnetization exclusively within one of two 10-nm thick magnetic nanolayers, separated by just 80 nm, without affecting the other one. The choice of the addressed layer is enabled by the excitation of a plasmon-polariton at a targeted interface of the nanostructure, and realized merely by rotating the polarization-axis of the linearly-polarized ultrashort optical pulse by 90°. Our results unveil a robust tool that can be deployed to reliably switch magnetization in targeted nanolayers of heterostructures, and paves the way to increasing the storage density of opto-magnetic recording by a factor of at least 2. The density of magnetic storage media is limited by the superparamagnetic limit when scaling down magnetic bits. Here, the authors open the way for stacked magnetic storage by using all-optical switching and addressing different magnetic layers by polarization-dependent excitation of plasmon-polaritons.