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An in vivo range verification technology for proton beam cancer therapy, preferably in real-time and with submillimeter resolution, is desired to reduce the present uncertainty in dose localization. Acoustical imaging technologies exploiting possible local interactions between protons and microbubbles or nanodroplets might be an interesting option. Unfortunately, a theoretical model capable of characterising the acoustical field generated by an individual proton on nanometer and micrometer scales is still missing. In this work, such a model is presented. The proton acoustic field is generated by the adiabatic expansion of a region that is locally heated by a passing proton. To model the proton heat deposition, secondary electron production due to protons has been quantified using a semi-empirical model based on Rutherford's scattering theory, which reproduces experimentally obtained electronic stopping power values for protons in water within 10% over the full energy range. The electrons transfer energy into heat via electron-phonon coupling to atoms along the proton track. The resulting temperature increase is calculated using an inelastic thermal spike model. Heat deposition can be regarded as instantaneous, thus, stress confinement is ensured and acoustical initial conditions are set. The resulting thermoacoustic field in the nanometer and micrometer range from the single proton track is computed by solving the thermoacoustic wave equation using k-space Green's functions, yielding the characteristic amplitudes and frequencies present in the acoustic signal generated by a single proton in an aqueous medium. Wavefield expansion and asymptotic approximations are used to extend the spatial and temporal ranges of the proton acoustic field.

BACKGROUND: Little is known about cerebral artery resistive index values in infants born extremely preterm. OBJECTIVE: To report resistive index values in various cerebral arteries in a prospective cohort of preterm infants born at

The closure of the valves generates shear waves in the heart walls. The propagation velocity of shear waves relates to stiffness. This could potentially be used to estimate the stiffness of the myocardium, with huge potential implications in pathologies characterized by a deterioration of the diastolic properties of the left ventricle. In an earlier phantom study we already validated shear wave tracking with a clinical ultrasound system in cardiac mode.In this study we aimed to measure the shear waves velocity in normal individuals.12 healthy volunteers, mean age=37±10, 33% females, were investigated using a clinical scanner (Philips iE33), equipped with a S5-1 probe, using a clinical tissue Doppler (TDI) application. ECG and phonocardiogram (PCG) were synchronously recorded. We achieved a TDI frame rate of500Hz by carefully tuning normal system settings. Data were processed offline in Philips Qlab 8 to extract tissue velocity along a virtual M-mode line in the basal third of the interventricular septum, in parasternal long axis view. This tissue velocity showed a propagating wave pattern after closure of the valves. The slope of the wave front velocity in a space-time panel was measured to obtain the shear wave propagation velocity. The velocity of the shear waves induced by the closure of the mitral valve (1st heart sound) and aortic valve (2nd heart sound) was averaged over 4 heartbeats for every subject.Shear waves were visible after each closure of the heart valves, synchronous to the heart sounds. The figure shows one heart cycle of a subject, with the mean velocity along a virtual M-mode line in the upper panel, synchronous to the ECG signal (green line) and phonocardiogram (yellow line) in the lower panel. The slope of the shear waves is marked with dotted lines and the onset of the heart sounds with white lines. In our healthy volunteer group the mean velocity of the shear wave induced by mitral valve closure was 4.8±0.7m/s, standard error of 0.14 m/s. The mean velocity after aortic valve closure was 3.4±0.5m/s, standard error of 0.09 m/s. We consistently found that for any subject the velocity after mitral valve closure was higher than after aortic valve closure.The velocity of the shear waves generated by the closure of the heart valves can be measured in normal individuals using a clinical TDI application. The shear wave induced after mitral valve closure was consistently faster than after aortic valve closure. Abstract P1138 Figure.Abstract P1138 Figure.

Process control in oil extraction and processing is traditionally done by independent control loops and logic (sequence) controls. In the best case, all controls are located in one central control room. The operator’s task is to draw the right conclusions from the process conditions signalled to him, to coordinate, to plan and to keep logsheets. On the basis of this information, he can coordinate between control loops and optimize unit operations. With the application of modern microelectronic-based control systems (integrated control systems), it is possible to present the operator’s information on a higher level (e.g., yield figures and energy consumptions computed from basic data), to do computerized planning operations and updatings, and to retrieve data which are used as an input for accounting systems and management information systems. Underlying principles, means for implementation, as well as benefits (both proven and potential) are described. The available hardware and software packages hardly form any limitations; on the contrary, we must often limit ourselves to optimal use of the available tools and not fall into the trap of “maximal automation.” Our aim is not to automate and control as much as possible, but to use automation as one of the means to process oilseeds and edible oils with the highest possible efficiency.

1. Zwischen Mesobronchus und Vestibulum ist eine Klappe vorhanden, welche wahrend der Inspiration geoffnet und wahrend der Exspiration geschlossen ist. Fur die Erklarung der bisher bekannt gewordenen Tatsachen bezuglich der Atmungsmechanik der Vogel ist die Annahme von weiteren Klappen uberflussig. 2. Bei der ruhig stehenden und ruhig atmenden Ente sind die hinteren Luftsacke aus mehreren Grunden fur die Ventilation der Lungen von viel groserer Bedeutung als die vorderen; die hinteren Sacke sind betrachtlich groser, sie werden viel ausgiebiger ventiliert, und bei der Exspiration wird die in ihnen enthaltene Luft (infolge des Verschlusses der unter 1. erwahnten Klappe) durch das ganze Parabronchiensystem geleitet. 3. Bei der stehenden Ente werden die abdominalen Sacke sehr gut, bei der in Ruckenlage liegenden Ente dagegen sehr schlecht oder gar nicht ventiliert. Der Einflus der Schwerkraft auf die Lage der abdominalen Sacke wurde durch Rontgenaufnahmen klargestellt. 4. Die Losung der Frage, ob bei der fliegenden Ente den vorderen Luftsacken vielleicht eine grosere Bedeutung fur die Ventilation der Lungen beizumessen ist, wie von Soum (1896) angenommen wurde, mus kunftigen Untersuchungen uberlassen bleiben.

BHT wurde sowohl allein als auch in Verbindung mit anderen Antioxydantien mit gutem Erfolg angewendet. Es ist neuerdings in USA in einer Konzentration von 0.01% zugelassen. Studies on the Application of Butylated hydroxy toluene as an Antioxidant in Foodstuffs BHT was tried out, either alone or in combination with other antioxidants with good result. It is now admitted in USA in a concentration of 0.01%.

Investigations on the use of the gallic acid esters, butylated hydroxyanisole, and butylated hydroxytoluene as antioxidants in animal fats, vegetable oils, margarine, and bakery products are described. It was found that the gallates and BHT were highly effective in lard; BHA was of lesser importance.