While the known modulation strategies for matrix converters are based on pulsewidth (PWM)-or vector modulation-this paper presents a novel time-discrete method real-time prediction calculation to select switching states. The decision about which state is be set following sampling period made by use of predictive quality function. Using this approach, unity displacement factor seen at supply side with minimum line current distortion while load currents follow their reference values good...

Abstract A method is described for multislice imaging by means of rf pulses which contain a multifrequency excitation spectrum. These label each slice an individual signal phase and allow the separation signals from all slices subsequent add/substract procedures. The image sensitivity corresponds to total number acquisitions. Sequences arbitrary with minimum experiments are described. © 1988 Academic Press, Inc.

To investigate whether changes in systemic pH affect intracellular (pHi), energy-rich phosphates, and lactic acid generation muscle, eight normal volunteers performed exhaustive forearm exercise with arterial blood flow occluded for 2 min on three occasions. Subjects ingested 4 mmol/kg NH4Cl (acidosis; A) or NaHCO3 (alkalosis; B) nothing (control; C) 3 h before the exercise. Muscle pHi phosphocreatine (PCr) content were measured 31P-nuclear magnetic resonance (31P-NMR) spectroscopy during...

Abstract. Energy metabolism of calf muscle was assessed non‐invasively by phosphorus ( 31 P) NMR spectroscopy in eleven patients with symptomatic arterial occlusion and seven matched controls. Phosphocreatine (PCr) content pH values decreased during non‐ischaemic foot exercise to lower severely afflicted but all patients, as a group, they were not significantly compared In contrast, recovery from ischaemic (arterial tourniquet) demonstrated significant differences between Intracellular PCr...

The demand for electric machines has been rising steadily several years—mainly due to the move away from combustion engine. Synchronous motors with rare earth permanent magnets are widely used their high power densities. These cost-intensive, cost-sensitive and often environmentally harmful. In addition dispensing magnets, electrically excited synchronous offer advantage of an adjustable excitation and, thus, a higher efficiency in partial load range field weakening operation. Field...

This paper presents the design and optimization process of a permanent magnetic excited transverse flux machine, which shall be used as shoulder joint motor in an articulated six axis robot arm service robotics. Starting from given application specific requirements, parametrized model machine is presented. For machines, typically high number parameters leads to large parameter space. A full factorial analysis simulating every possible variation would lead simulation times order years....

While known modulation strategies for matrix converters are based on PWM or vector-modulation, this paper presents a novel time-discrete method by which the switching state of converter is changed only at equidistant points in time. The decision about to be set following sampling period, made use quality function. Using approach, selected such way as unity displacement factor seen supply side whilst load currents follow their reference values with good accuracy. function mentioned above...

This paper presents requirements on a articulated robot arm in service robotics and the derivation of single joint this arm. A modular concept with modules, each one realizing axis connected by intermediate elements is proposed. Furthermore, integration permanent magnet excited transverse flux machine as drive application discussed. Transverse machines typically offer high torque density at low speed. As demand increases from wrist to shoulder speed decreases same time, concentrates design...

Abstract 13 C spectroscopic imaging (SI) is implemented and tested on a Siemens whole‐body MR instrument for in vivo localized spectroscopy. The method provides maps of extended regions interest. It found that SI an ideal field application the technique since most other localization methods suffer from chemical‐shift or offset artifacts this nucleus. Applications with single rf channel as well combination polarization transfer experiments heteronuclear broadband decoupling are shown. © 1989...

Electrically excited synchronous machines do not require expensive and temperature-dependent permanent magnets. Therefore they offer more safety, because there is no induced voltage when the excitation current has been turned off. For these reasons, electrically are getting interesting for different applications like electrical vehicles. reaching higher torque power density, an operation with high flux density necessary. Hence, behavior of machine nonlinear. Through possibility varying rotor...

Abstract In conventional ECG gated multislice imaging of the heart, slice position and phase in heart cycle are not independent parameters. This drawback is removed by simultaneous multiple slices. paper describes a technique which based on excitation several slices multifrequency selective rf pulses. comparison to cardiac an improved quality images obtained, because more acquisitions attributed MR signal The gain signal‐to‐noise ratio per measurement time increases with square root number...

In order to increase torque and power density, novel electrical machines with a 3D magnetic flux path are used. One of them is the transverse machine, which offers high at low speed therefore predestined for use as near-wheel drive in an vehicle or joint robot arm. contrast typical machines, such synchronous has component radial plane. Additionally, materials highly saturated achieve density. The aim, beside reach efficiency. This especially necessary mobile applications batteries, robot....

In order to increase torque and power density novel electrical machines often have 3D magnetic flux in soft materials. Therefore, an isotropic permeability is required. Soft Magnetic Composites offer this attribute are predestinated for application. To achieve higher less iron losses useful. Hence, paper presents different ways calculate composites. Starting with classical Steinmetz Equation, several further extensions presented. These methods may be used calculating during the optimization...

Abstract Recently significant changes of human brainstem auditory evoked potentials (BAEP) after exposure to static magnetic fields were reported (L. von Klitzing, Clin. Physiol. Meas. 7(2), 157 (1986); L. Stojan, D. Sperber, and K. Dransfeld, Naturwissenschaften 75, 622 (1988)). We recorded BAEPs 11 subjects before a routine MRI examination at 1.5 T. In addition the BAEP healthy volunteer was measured in five different (0‐2.0 T). Our results indicate that investigations do not significantly...

MR spectra simultaneously acquired from different locations in the human body may be obtained with SIMUVOSP technique (Simultaneous Multivolume Spectroscopy). is based on multifrequency selective RF pulses which encode positional information of spins into phase signal. This paper describes strategies for 1H, 31P and 13C spectroscopy. For 1H STEAM experiment modified by replacing SIMUFREX Multifrequency Excitation pulses). modification allows simultaneous spectroscopic examination regions...

Adopting electrically excited synchronous machines (EESM) as traction in electric vehicles has multiple advantages such no usage of rare earth magnets, high power density and unity factor over a wide operating range. Combining the EESM with contactless, inductive transfer system (WPT) eliminates drawbacks slip rings brushes dust generation wear tear. Utilizing WPT for rotor requires current observer closed-loop control direct measurement is unfeasible. In this publication, stator flux...