High Temperature Resistant Eddy Current Sensor for “in situ” Monitoring the Material Microstructure Development of Steel Alloys during Heat Treatment : Bainite Sensor

Production of tools and component for automotive and energy production includes in most application the adjustment in hardness, toughness, fatigue and wear properties. This is done by heat treatment [4]. Depending on material and Target course different treatment processes are applied like martensitic hardening, bainitic hardening [3], nitriding, nitrocarburizing, carburizing and annealing. Up to now these heat treatment processes are done by recipe.Temperature and time of treatment are measured. No information about the change in material microstructure is available during treatment. So scattering results are the consequence and high security time factors have to be Included to get the necessary process capability. To overcome this difficulty, eddy current sensors, measuring and analysis systems have been developed and are implemented in the hot furnace to measure in-situ the progress of thedeveloping material microstructure during heat treatment of the components

Setting Discrete Yield-stress Sensors for Recording Early Component Loading Using Eddy-current Array Technology and Induction Thermography

Problematic requirements, regarding the assessment of the integrity of highly loaded components require that modern methods be developed to record the component's loading history during its life cycle. New developments are moving towards a continuous monitoring of loading history using sensors as well as towards determing the material's or component's state during its service. This requires integrating the load sensors into the component in order to record the component's loading online. Based on the physical material properties of metastable austenitic steels, a novel design is developed for implementing local, component-inherent load sensors; so-called directionally-sensitive yield-stress sensors. The appropriate strengths and yield stresses, corresponding to the component loading to be monitored, can be specifically set by locally heat treating the selected, cold-worked sensor's region using a fibre-laser. Electromagnetic testing methods, such as eddy current technology and imaging induction thermography are developed to rapidly collect the technical data of such microstructures which possess modified physical material properties. The measuring technology is developed and adapted to the testing task via modelling. FEM computation are also performed both for describing the domain's scope and the eddy current distribution, as well as for simulating the magnetising processes as well as the chronological formation of temperature fields in the component's edge region

Stoerungspraevention bei Zerlegearbeiten in kerntechnischen Anlagen durch Spannungsmessung Schlussbericht

The dismantling of nuclear facilities is in progress since 20 years in Germany. Practical experiences in decommissioning have shown, that problem can occur during dismantling operations caused by release of residual stresses. In this case cutting parts or cutting tools get jammed if mechanical cutting techniques are used. The aim of this research work was to develop measuring techniques for the determination of the stress state in RPV, to predict the deformation during dismantling operations. This can serve as additional base for improved decommissioning planning and for time optimised dismantling. For determination of the stress state in components two small and inexpensive measuring techniques were new designed, for remote-controlled on-site use in atmosphere and under water. For the nondestructive determination of the directional stress state, based on the magnetostriction and the Harmonic-Analysis of alternating magnetic fields, a new developed rotating sensor is in use with a principal magnetisation direction. Because of the mainly isotropic material properties and the directional stresses, measured Harmonic values are influenced mainly by the stress state in the surface areas. In this way it is possible to determine the stress state qualitatively and the direction of principal stresses in the surface areas of the component. As an alternative to the established wire strain gauge, which remote-controlled application is still not possible under water, a new slot jet cutting strain control technique was designed. This technique detects the deformation in the surface after stresses are cut free by a water jet. So the stress state could be determined quantitatively in the surface and assessed in the depth. With the help of these two measuring techniques it is possible to characterize the stress state along a planned cutting line. The use of an adapted FEM simulation enables to calculate and determine the deformation of the cutting gap beforehand. These information can be used to work out a dismantling strategy that guarantees an undisturbed dismantling. (orig.)SIGLEAvailable from TIB Hannover: F04B1915 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung und Forschung (BMBF), Bonn (Germany)DEGerman

Changes of Subsurface Properties due to Fatigue Determined by Sin2ψ-method and Harmonic Analysis of Eddy Current Signals

Monitoring residual stress relaxation due to mechanical loading has the capability to retrieve a component's load history. So far, these changes are determined by X-ray diffraction using the sin2ψ-method going along with high effort regarding specimen preparation, measurement time and costs. The presented paper evaluates harmonic analysis of eddy current measurements as an alternative technology to determine alterations of a component's subsurface due to fatigue. Transferring this approach to a wide range of machined components and mass production bears the potential to gain access to large databases of service life information, representing an important enabling technology for cyber-physical systems

Sensorik fuer ein Unterwasser-Handhabungssystem fuer Mess- und Schneidarbeiten bei der Demontage stillgelegter kerntechnischer Anlagen Ergebnisbericht

Not only manipulators are necessary for dismantling and inspection of structure parts in decomissioned nuclear facilities, but flexible underwater-vehicles. Free-diving underwater-vehicles for inspection and dismantling tasks are still not developed and tested. Aim of the project is the development of sensors and devices for the position determination and the depth regulation. For inspection tasks an ultrasonic measurement and dosimeter device shall be built up. A measurement device has been developed which evaluates the ultrasonic time of flight from a transmitter at the vehicle to several receivers, installed in the reactor pressure vessel. The depth regulation is based on a pressure sensor and the direct control of the thrusters. The ultrasonic measurements are realized by an adapted ultrasonic card, the #gamma#-dosimetry with an ionization chamber and a pA-amplifier. An acoustic orientation system was built up, which measures very accurately with one transmitter mounted on the vehicle and four receivers. Problem occur by reflection from the walls of the basin. The depth regulation is working faultless. The ultrasonic device is preferably used for distance measurement. The radiation measurement device was tested and mounted in the vehicle. (orig./HP)Zur Stillegung kerntechnischer Anlagen werden auch flexible Unterwasserfahrzeuge. Freitauchende Unterwasserfahrzeuge, die Inspektions- und Demontageaufgaben uebernehmen koennen, sind bisher noch nicht fuer den Einsatz im Reaktordruckbehaelter entwickelt und erprobt worden. Ziel ist der Aufbau einer Sensorik fuer die Positionsbestimmung und Tiefenregelung des Fahrzeuges. Fuer Inspektionsarbeiten sollen ein Ultraschallsystem und ein radiologisches Messsystem am Fahrzeug aufgebaut werden. Entwickelt wird eine Messelektronik, die die Ultraschallaufzeit von einem Sender am Fahrzeug zu mehreren Empfaengern, die im Reaktordruckbehaelter installiert werden. Die Tiefenregelung erfolgt ueber einen Drucksensor und direkter Ansteuerung der Fahrzeugantriebe. Die Ultraschallmessungen werden durch einen Sensor und eine adaptierte Ultraschallkarte durchgefuehrt. Die Dosisleistungsmessung wird ueber eine Ionisationskammer und einen pA-Verstaerker realisiert. Es wurde ein Ortungssystem aufgebaut, das ueber einen Schallsender am Unterwasserfahrzeug und vier Empfaenger eine sehr genaue Laufzeitmessung durchfuehrt. Probleme ergeben sich durch die nur langsam abklingenden Schallreflexionen von den Waenden des Beckens. Die Tiefenregelung arbeitet einwandfrei. Die Ultraschallkarte wird hauptsaechlich zur Abstandsmessung eingesetzt. Das dosimetrische Messsystem wurde getestet und in das Fahrzeug eingebaut. (orig./HP)SIGLEAvailable from TIB Hannover: F95B43 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Forschung und Technologie (BMFT), Bonn (Germany)DEGerman

Cryo-EM Structures of a Gonococcal Multidrug Efflux Pump Illuminate a Mechanism of Drug Recognition and Resistance

Neisseria gonorrhoeae has become a highly antimicrobial-resistant Gram-negative pathogen. Multidrug efflux is a major mechanism that N. gonorrhoeae uses to counteract the action of multiple classes of antibiotics. It appears that gonococci bearing mosaic-like sequences within the gene mtrD, encoding the most predominant and clinically important transporter of any gonococcal multidrug efflux pump, significantly elevate drug resistance and enhance transport function. Here, we report cryo-electron microscopy (EM) structures of N. gonorrhoeae MtrD carrying a mosaic-like sequence that allow us to understand the mechanism of drug recognition. Our work will ultimately inform structure-guided drug design for inhibiting these critical multidrug efflux pumps.Neisseria gonorrhoeae is an obligate human pathogen and causative agent of the sexually transmitted infection (STI) gonorrhea. The most predominant and clinically important multidrug efflux system in N. gonorrhoeae is the multiple transferrable resistance (Mtr) pump, which mediates resistance to a number of different classes of structurally diverse antimicrobial agents, including clinically used antibiotics (e.g., β-lactams and macrolides), dyes, detergents and host-derived antimicrobials (e.g., cationic antimicrobial peptides and bile salts). Recently, it has been found that gonococci bearing mosaic-like sequences within the mtrD gene can result in amino acid changes that increase the MtrD multidrug efflux pump activity, probably by influencing antimicrobial recognition and/or extrusion to elevate the level of antibiotic resistance. Here, we report drug-bound solution structures of the MtrD multidrug efflux pump carrying a mosaic-like sequence using single-particle cryo-electron microscopy, with the antibiotics bound deeply inside the periplasmic domain of the pump. Through this structural approach coupled with genetic studies, we identify critical amino acids that are important for drug resistance and propose a mechanism for proton translocation

Einfluss von Parameteraenderungen auf das dynamische Verhalten beschaufelter Laeufer Abschlussbericht zum Teilprojekt D 5, Teil 2

TIB: RN 3500 (53)+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman