Signal-to-noise ratio enhanced electrode configurations for magnetoelectric cantilever sensors

Magnetoelectric cantilevers consisting of strain-coupled magnetostrictive and piezoelectric (PE) layers are applicable to magnetic-fi eld sens- ing. For the fi rst bending mode, the magnetic fi eld-induced stress distribution is of equal sign along the cantilever length. Thus, a plate- capacitor electrode configuration encompassing the complete PE layer may be used for collecting the strain-induced charge. For higher order modes, stress regions of the opposite sign occur in the cantilever length direction. To prevent charge cancellation and to harvest the piezo- electric induced charge effi ciently, segmented electrodes are employed. This study investigates the effect of the electrode confi gurationon the signal-to-noise ratio (SNR) for higher order bending modes. The charges collected by the electrodes are calculated using a fi nite element method simulation considering the mechanical, electrical, and magnetic properties of the cantilever. By combination with an analytic noise model, taking into account the sensor and amplifi er noise sources, the SNR is obtained. We analyze a 3 mm long, 1 mm wide, and 50 μm thick silicon cantilever with layers of 2 μm magnetostrictive soft amorphous metal (FeCoSiB) and 2 μm piezoelectric aluminum nitride. We demonstrate that an SNR-optimized electrode design yields an SNR improvement by 2.3 dB and 2.4 dB for the second and third bending modes compared to a signal optimized design

Historische Demographie mittels Familienrekonstitution : Die Bevölkerung des Monschauer Landes im 19. Jahrhundert

Das Monschauer Land des 19. Jahrhunderts besteht aus der Stadt Monschau und den umliegenden Dörfern, die untereinander in regem Austausch stehen und stark miteinander verflochten sind, aber aufgrund ihrer geographischen Lage von der weiteren Umgebung weit gehend separiert sind. Die Untersuchung fokussiert einen Zeitraum von 70 Jahren (1806 bis 1875) und betrachtet dabei eine Zeit des gesellschaftlichen Wandels mit einer zu Beginn starken Textilindustrie, die aber, bedingt durch die abgeschiedene Lage des Monschauer Landes, letztlich mit der Entwicklung nicht Schritt halten kann. Abgesehen von wenigen Berichten, beispielsweise in Form von Tagebuchaufzeichnungen, bleibt die Geschichte des größten Teils der Bevölkerung im Dunkeln. Untersuchungen von Einzelschicksalen anhand derartiger Quellen sind eher zufälliger Natur. Lediglich in Zivilstandsurkunden, die für das gesamte 19. Jahrhundert vorliegen, werden Angaben zu jeder einzelnen Person gemacht. Zwar finden sich hier nur wenige Eckdaten des Lebens – Geburten, Hochzeiten, Sterbefälle –, diese sind aber unabhängig vom gesellschaftlichen Stand für die gesamte Bevölkerung festgehalten. Diese Vollständigkeit erweist sich als hilfreich, einen Einblick in die Geschichte zu erhalten, der weit über Einzelbeobachtungen hinausgeht. In dieser Arbeit wird gezeigt, welche Erkenntnisse durch das Studium primärer Quellen, in diesem Fall den Zivilstandsurkunden, gewonnen werden können. Einfachstes Datenmaterial, bestehend aus Datumsangaben und Namen, dient als Grundlage für die Durchführung von Familienrekonstitutionen. Hierzu werden Angaben aus den Zivilstandsurkunden jeweils für eine Kernfamilie zusammengetragen und miteinander verknüpft. Dieser innerdemographisch-mikrohistorische Ansatz bietet die Möglichkeit, zusammen mit zusätzlichen Personendaten zu Beruf, Herkunft und Todesursache, umfassende Untersuchungen vorzunehmen. Darauf fußende statistische Berechnungen sind nicht nur abstraktes Zahlenmaterial, sondern ein echtes Abbild des Lebens der Bevölkerung und geben die Möglichkeit, ökonomische und kulturelle Einflüsse auf ihr Leben aufzudecken. Den Hauptteil der Arbeit bilden die innerdemographischen Untersuchungen unter Verwendung der Daten aus den durchgeführten Familienrekonstitutionen. In drei übergeordneten Kapiteln werden, gemäß der in den Zivilstandsurkunden festgehaltenen Eckpunkte des Lebens – Heiraten, Geburten und Sterben –, Aspekte des Heiratsverhaltens, der Fruchtbarkeit und der Sterblichkeit eingehender beleuchtet. Mittels dieser Methode werden umfangreiche Kenntnisse gewonnen, die anhand von tabellarischen Auflistungen der Personendaten nicht ersichtlich wären. So lässt sich beispielsweise die komplexe Abhängigkeit von Säuglingssterblichkeit, dem Alter der Mutter, dem Geburtenabstand und dem Überleben des vorangegangenen Säuglings darstellen. Mittels der Geburtenabstände kann die Fruchtbarkeit erforscht werden, obwohl keine Daten über die Gesamtbevölkerung vorliegen. Durch eine einfache Verknüpfung zwischen Berufsangabe und Entfernung zum Herkunftsort der Ehepartner können schichtspezifische Merkmale für die Partnerwahl aufgedeckt werden. Um eine Vergleichbarkeit mit anderen Untersuchungen zu gewährleisten, sind die Diagramme und Tabellen in Berechnung und Darstellung weitestgehend an Arbeiten von Knodel und Wrigley angelehnt

Investigation of Unwanted Oscillations of Electrically Modulated Magnetoelectric Cantilever Sensors

Magnetoelectric thin-film cantilevers consisting of strain-coupled magnetostrictive and piezoelectric layers are promising candidates for magnetic field measurements in biomedical applications. In this study, we investigate magnetoelectric cantilevers that are electrically excited and operated in a special mechanical mode with resonance frequencies above 500 kHz. In this particular mode, the cantilever bends in the short axis, forming a distinctive U-shape and exhibiting high-quality factors and a promising limit of detection of 70pT/Hz1/2 at 10 Hz. Despite this U mode, the sensors show a superimposed mechanical oscillation along the long axis. The induced local mechanical strain in the magnetostrictive layer results in magnetic domain activity. Due to this, the mechanical oscillation may cause additional magnetic noise, deteriorating the limit of detection of such sensors. We compare finite element method simulations with measurements of magnetoelectric cantilevers in order to understand the presence of oscillations. From this, we identify strategies for eliminating the external effects that affect sensor operation. Furthermore, we investigate the influence of different design parameters, in particular the cantilever length, material parameters and the type of clamping, on the amplitude of the undesired superimposed oscillations. We propose design guidelines to minimize the unwanted oscillations

New approach to the visualization of international scientific collaboration

Chinchilla-Rodríguez, Z., Vargas-Quesada, B., Hassan-Montero, Y., González-Molina, A., Moya-Anegón, F. New approach to the visualization of international scientific collaboration. Information Visualization, 9 (4): 277-287, Winter 2010. DOI: 10.1057/ivs.2009.31In this study, visual representations are created in order to analyze different aspects of scientific collaboration at the international level. The main objective is to identify the international facet of research by following the flow of knowledge as expressed by the number of scientific publications, and then establishes the main geographical axes of output, showing the interrelationships of the domain, the intensity of these relations, and how the different types of collaboration are reflected in terms of visibility. Thus, the methodology has a twofold application, allowing us to detect significant differences that help characterize patterns of behaviour of a geographical system of output, along with the generation of representations that serve as interfaces for domain analysis and information retrieval.Peer reviewe

Use and Reporting of Patient-Reported Outcomes in Trials of Palliative Radiotherapy: A Systematic Review

Two authors independently assessed eligibility. Trial characteristics were extracted and standard of PRO reporting was assessed in adherence to the Consolidated Standards of Reporting Trials (CONSORT) PRO extension. The association of the year of publication with the use of PROs was assessed by logistic regression. Factors associated with higher CONSORT-PRO adherence were analyzed by multiple regression. This study is reported following the PRISMA guidelines.Among 7377 records screened, 225 published clinical trials representing 24 281 patients were eligible. Of these, 45 trials (20%) used a PRO as a primary end point and 71 trials (31%) used a PRO as a secondary end point. The most prevalent PRO measures were the Numeric Rating Scale/Visual Analogue Scale (38 trials), European Organization for the Research and Treatment of Cancer Quality of Life Questionnaire C30 (32 trials), and trial-specific unvalidated measures (25 trials). A more recent year of publication was significantly associated with a higher chance of PROs as a secondary end point (odds ratio [OR], 1.04 [95% CI, 1.00-1.07]; P = .03) but not as primary end point. Adherence to CONSORT-PRO was poor or moderate for most items. Mean (SD) adherence to the extension adherence score was 46.2% (19.6%) for trials with PROs as primary end point and 31.8% (19.8%) for trials with PROs as a secondary end point. PROs as a primary end point (regression coefficient, 9.755 [95% CI, 2.270-17.240]; P = .01), brachytherapy as radiotherapy modality (regression coefficient, 16.795 [95% CI, 5.840-27.751]; P = .003), and larger sample size (regression coefficient, 0.028 [95% CI, 0.006-0.049]; P = .01) were significantly associated with better PRO reporting per extension adherence score. Conclusions and relevance In this systematic review of palliative radiotherapy trials, the use and reporting of PROs had room for improvement for future trials, preferably with PROs as a primary end point

Multi-Mode Love-Wave SAW Magnetic-Field Sensors

A surface-acoustic-wave (SAW) magnetic-field sensor utilizing fundamental, first- and second-order Love-wave modes is investigated. A 4.5   μ m SiO2 guiding layer on an ST-cut quartz substrate is coated with a 200 n m (Fe90Co10)78Si12B10 magnetostrictive layer in a delay-line configuration. Love-waves are excited and detected by two interdigital transducers (IDT). The delta-E effect in the magnetostrictive layer causes a phase change with applied magnetic field. A sensitivity of 1250 ° / m T is measured for the fundamental Love mode at 263 M Hz . For the first-order Love mode a value of 45 ° / m T is obtained at 352 M Hz . This result is compared to finite-element-method (FEM) simulations using one-dimensional (1D) and two-and-a-half-dimensional (2.5 D) models. The FEM simulations confirm the large drop in sensitivity as the first-order mode is close to cut-off. For multi-mode operation, we identify as a suitable geometry a guiding layer to wavelength ratio of h GL / λ ≈ 1.5 for an IDT pitch of p = 12   μ m . For this layer configuration, the first three modes are sufficiently far away from cut-off and show good sensitivity

Optoelectronic System Measures Distances to Multiple Targets

An optoelectronic metrology apparatus now at the laboratory-prototype stage of development is intended to repeatedly determine distances of as much as several hundred meters, at submillimeter accuracy, to multiple targets in rapid succession. The underlying concept of optoelectronic apparatuses that can measure distances to targets is not new; such apparatuses are commonly used in general surveying and machining. However, until now such apparatuses have been, variously, constrained to (1) a single target or (2) multiple targets with a low update rate and a requirement for some a priori knowledge of target geometry. When fully developed, the present apparatus would enable measurement of distances to more than 50 targets at an update rate greater than 10 Hz, without a requirement for a priori knowledge of target geometry. The apparatus (see figure) includes a laser ranging unit (LRU) that includes an electronic camera (photo receiver), the field of view of which contains all relevant targets. Each target, mounted at a fiducial position on an object of interest, consists of a small lens at the output end of an optical fiber that extends from the object of interest back to the LRU. For each target and its optical fiber, there is a dedicated laser that is used to illuminate the target via the optical fiber. The targets are illuminated, one at a time, with laser light that is modulated at a frequency of 10.01 MHz. The modulated laser light is emitted by the target, from where it returns to the camera (photodetector), where it is detected. Both the outgoing and incoming 10.01-MHz laser signals are mixed with a 10-MHz local-oscillator to obtain beat notes at 10 kHz, and the difference between the phases of the beat notes is measured by a phase meter. This phase difference serves as a measure of the total length of the path traveled by light going out through the optical fiber and returning to the camera (photodetector) through free space. Because the portion of the path length inside the optical fiber is not ordinarily known and can change with temperature, it is also necessary to measure the phase difference associated with this portion and subtract it from the aforementioned overall phase difference to obtain the phase difference proportional to only the free-space path length, which is the distance that one seeks to measure. Therefore, the apparatus includes a photodiode and a circulator that enable measurement of the phase difference associated with propagation from the LRU inside the fiber to the target, reflection from the fiber end, and propagation back inside the fiber to the LRU. Because this phase difference represents twice the optical path length of the fiber, this phase difference is divided in two before subtraction from the aforementioned total-path-length phase difference. Radiation-induced changes in the photodetectors in this apparatus can affect the measurements. To enable calibration for the purpose of compensation for these changes, the apparatus includes an additional target at a known short distance, located inside the camera. If the measured distance to this target changes, then the change is applied to the other targets

PARP1 catalytic variants reveal branching and chain length-specific functions of poly(ADP-ribose) in cellular physiology and stress response

Poly(ADP-ribosyl)ation regulates numerous cellular processes like genome maintenance and cell death, thus providing protective functions but also contributing to several pathological conditions. Poly(ADP-ribose) (PAR) molecules exhibit a remarkable heterogeneity in chain lengths and branching frequencies, but the biological significance of this is basically unknown. To unravel structure-specific functions of PAR, we used PARP1 mutants producing PAR of different qualities, i.e. short and hypobranched (PARP1\G972R), short and moderately hyperbranched (PARP1\Y986S), or strongly hyperbranched PAR (PARP1\Y986H). By reconstituting HeLa PARP1 knockout cells, we demonstrate that PARP1\G972R negatively affects cellular endpoints, such as viability, cell cycle progression and genotoxic stress resistance. In contrast, PARP1\Y986S elicits only mild effects, suggesting that PAR branching compensates for short polymer length. Interestingly, PARP1\Y986H exhibits moderate beneficial effects on cell physiology. Furthermore, different PARP1 mutants have distinct effects on molecular processes, such as gene expression and protein localization dynamics of PARP1 itself, and of its downstream factor XRCC1. Finally, the biological relevance of PAR branching is emphasized by the fact that branching frequencies vary considerably during different phases of the DNA damage-induced PARylation reaction and between different mouse tissues. Taken together, this study reveals that PAR branching and chain length essentially affect cellular functions, which further supports the notion of a ‘PAR code’