Al2O3 Precursor Evaluation for SALD Joining

SFF technology is not limited to the creation of components and objects. Freeform technology can be a mechanism for joining of materials. By defining the space between two objects as the boundary for a free-form object it is possible to form a three dimensional joint fill. Selective Area Laser Deposition or SALD, has been used for free form and joining of carbides and nitrides but has the potential to make other classes of ceramics. By selecting a metal-organic precursor and an oxidizer, an oxide can be created by CVD gas decomposition. In this study such oxide joint fill precursors are studied, particularly for alumina.Mechanical Engineerin

Ceramic Joining by Gas Phase Pulsed Laser Processing

The method of Selective Area Laser Deposition (SALD) and Vapor Infiltration (SALDVI) has been successfully used to fabricate small three-dimensional SiC/SiC and SiC/metal powder parts. Ceramic joints made by this technique have been limited by the throwing power of the laser resulting in incomplete joint penetration. Studies were performed to show the effectiveness of a fiber laser, with a wavelength of 1070 nm, for a joining process. The ability of the laser to penetrate a powder bed was utilized in the joint fabrication. The combination of powder fill, and deep laser penetration into the powder bed shows potential in the field of ceramic joining.Mechanical Engineerin

New Photodetection Method Using Unbalanced Sidebands for Squeezed Quantum Noise in Gravitational Wave Interferometer

Homodyne detection is one of the ways to circumvent the standard quantum limit for a gravitational wave detector. In this paper it will be shown that the same quantum-non-demolition effect using homodyne detection can be realized by heterodyne detection with unbalanced RF sidebands. Furthermore, a broadband quantum-non-demolition readout scheme can also be realized by the unbalanced sideband detection.Comment: 9 pages, 5 figure

Intrathekale Opioidmedikation zur perioperativen Analgesie bei schwer behinderten Kindern mit Wirbelsäulenoperationen

Zusammenfassung: Hintergrund: An gesunden Kindern konnte gezeigt werden, dass intrathekal verabreichte Opioide eine sichere und effektive perioperative Analgesie bei wirbelsäulenchirurgischen Eingriffen ermöglichen. Das Ziel der vorliegenden Untersuchung ist es, ihre Anwendbarkeit bei schwer- und schwerstbehinderten Kindern für wirbelsäulenchirurgische Eingriffe zu überprüfen. Methode: Mit Zustimmung der lokalen Ethikkommission wurden Patienten vom Status3 und 4 der Klassifikation der American Society of Anesthesiologists (ASA), die sich einem wirbelsäulenchirurgischen Eingriff unterziehen mussten, retrospektiv untersucht. Zusätzlich zur Allgemeinanästhesie mit Sevofluran oder i.v.-verabreichtem Propofol erhielten die Patienten vor der Operation 20µg/kgKG Morphin und 1,5µg/kgKG Sufentanil intrathekal. Nach Beendigung des Eingriffs wurde eine Nalbuphindauerinfusion gestartet. Der Bedarf an zusätzlichen intra- und postoperativen Analgetika, der Zeitpunkt der Extubation, die postoperativen Schmerz-Scores und die arteriellen Kohlendioxidpartialdruck- (paCO2)-Werte sowie das Auftreten unerwünschter Nebenwirkungen wurden untersucht. Ergebnisse: Es wurden 28Patienten im Alter von 2,8 bis 18,5Jahren (Median 11,6Jahre) untersucht. Unmittelbar im OP konnten 17Patienten extubiert werden; bei 11Patienten entschied man sich zu einer verzögerten Extubation. Bis auf einen Patienten mit postoperativer Massivtransfusion konnten alle innerhalb von 24h extubiert werden. Eine adäquate postoperative Analgesie mit Schmerz-Scores ≤3 wurde mithilfe der Kombination von intrathekal verabreichten Opioiden mit Nalbuphin postoperativ bei 26 von 28Patienten (93%) erreicht. Bei 2Patienten war der Wechsel auf eine i.v.-Morphin-Gabe erforderlich. Postoperative Übelkeit und Erbrechen ("postoperative nausea and vomiting", PONV), Pruritus und leichte Hypoventilation mit paCO2-Werten zwischen 5,2 bis 9,7kPa (Median 6,3kPa) waren die beobachteten Nebenwirkungen. Schlussfolgerung: Der Einsatz intrathekal verabreichter Opioide, ergänzt durch eine postoperative Nalbuphininfusion, erlaubt in den allermeisten Fällen eine frühzeitige Extubation ohne persistierende Atemdepression und ist eine praktikable sowie effektive Methode zur postoperativen Analgesie bei schwer behinderten Kindern nach wirbelsäulenchirurgischen Eingriffe

Weak-Localization in Chaotic Versus Non-Chaotic Cavities: A Striking Difference in the Line Shape

We report experimental evidence that chaotic and non-chaotic scattering through ballistic cavities display distinct signatures in quantum transport. In the case of non-chaotic cavities, we observe a linear decrease in the average resistance with magnetic field which contrasts markedly with a Lorentzian behavior for a chaotic cavity. This difference in line-shape of the weak-localization peak is related to the differing distribution of areas enclosed by electron trajectories. In addition, periodic oscillations are observed which are probably associated with the Aharonov-Bohm effect through a periodic orbit within the cavities.Comment: 4 pages revtex + 4 figures on request; amc.hub.94.

A constructive approach to the soliton solutions of integrable quadrilateral lattice equations

Scalar multidimensionally consistent quadrilateral lattice equations are studied. We explore a confluence between the superposition principle for solutions related by the Backlund transformation, and the method of solving a Riccati map by exploiting two kn own particular solutions. This leads to an expression for the N-soliton-type solutions of a generic equation within this class. As a particular instance we give an explicit N-soliton solution for the primary model, which is Adler's lattice equation (or Q4).Comment: 22 page

Corrections to the Central Limit Theorem for Heavy-Tailed Probability Densities

Classical Edgeworth expansions provide asymptotic correction terms to the Central Limit Theorem (CLT) up to an order that depends on the number of moments available. In this paper, we provide subsequent correction terms beyond those given by a standard Edgeworth expansion in the general case of regularly varying distributions with diverging moments (beyond the second). The subsequent terms can be expressed in a simple closed form in terms of certain special functions (Dawson's integral and parabolic cylinder functions), and there are qualitative differences depending on whether the number of moments available is even, odd or not an integer, and whether the distributions are symmetric or not. If the increments have an even number of moments, then additional logarithmic corrections must also be incorporated in the expansion parameter. An interesting feature of our correction terms for the CLT is that they become dominant outside the central region and blend naturally with known large-deviation asymptotics when these are applied formally to the spatial scales of the CLT

Didactic Software for Autistic Children

In this paper we describe the aims and requirements of a project devoted to designing and developing Open Source didactic Software (SW) for children in the autism disorder spectrum, conforming to the Applied Behaviour Analysis (ABA) learning technique. In this context, participatory design with therapists and child?s parents is necessary to ensure a usable product that responds to these children?s special needs and respects education principles and constraints of the ABA methodology