Reflectance Pulse Oximetry - Principles and Obstetric Application in the Zurich System

Transmission and reflectance are the two main modes of pulse oximetry. In obstetrics, due to the absence of a transilluminable fetal part for transmission oximetry, the only feasible option is the reflectance mode, in which sensor and detector are located on the same surface of the body part. However, none of the reflectance pulse oximeters developed for intrapartum use are fully satisfactory, as indicated by the fact that none have entered routine use. We have designed, developed, constructed and tested a reflectance pulse oximeter with the possibility to adjust the electronic circuits and signal processing in order to determine the effects of various parameters on signal amplitude and wave-form and to optimize the sensitivity and spatial arrangement of the optical elements. Following an explanation of the principles of reflectance pulse oximetry, we report our experience with the design, development, construction and field-testing of an in-house reflectance pulse oximetry system for obstetric applicatio

Activated carbon as catalyst support: precursors, preparation, modification and characterization

The preparation of activated carbon materials is discussed along selected examples of precursor materials, of available production and modification methods and possible characterization techniques. We evaluate the preparation methods for activated carbon materials with respect to its use as catalyst support and identify important parameters for metal loading. The considered carbon sources include coal, wood, agricultural wastes or biomass as well as ionic liquids, deep eutectic solvents or precursor solutions. The preparation of the activated carbon usually involves pre-treatment steps followed by physical or chemical activation and application dependent modification. In addition, highly porous materials can also be produced by salt templating or ultrasonic spray pyrolysis as well as by microwave irradiation. The resulting activated carbon materials are characterized by a variety of techniques such as SEM, FTIR, nitrogen adsorption, Boehm titrations, adsorption of phenol, methylene blue and iodine, TPD, CHNS/O elemental analysis, EDX, XPS, XRD and TGA

Ein Jahr virtuelle Medienausleihe, ein Praxisbericht

E-Books, E-Audios, E-Music, E-Videos und E-Papers per Download: rund um die Uhr und unabhängig vom Aufenthaltsort können eingeschriebene Bibliotheksbenutzer digitale Medien ausleihen – angesichts des Wandels beim Mediennutzungsverhalten ein wichtiger Beitrag zur Kundenbindung. Voraussetzung ist die Wahrung der Urheberrechte, was zahlreiche technische Implikationen nach sich zieht und die Zusammenarbeit mit der Firma DiViBib GmbH nahe legt. Was bieten die Verlage an, was suchen die Kunden der Öffentlichen Bibliotheken? Was spricht für die Nutzung der Onleihe, welche Probleme kann es geben? Wie präsentiert man ein virtuelles Angebot? Und wie reagieren unsere Kunden darauf

Structural Correctness of Planning Processes in Building Engineering

The planning of projects in building engineering is a complex process which is characterized by a dynamical composition and many modifications during the definition and execution time of processes. For a computer-aided and network-based cooperation a formal description of the planning process is necessary. In the research project “Relational Process Modelling in Cooperative Building Planning” a process model is described by three parts: an organizational structure with participants, a building structure with states and a process structure with activities. This research project is part of the priority program 1103 “Network-Based Cooperative Planning Processes in Structural Engineering” promoted by the German Research Foundation (DFG). Planning processes in civil engineering can be described by workflow graphs. The process structure describes the logical planning process and can be formally defined by a bipartite graph. This structure consists of activities, transitions and relationships between activities and transitions. In order to minimize errors at execution time of a planning process a consistent and structurally correct process model must be guaranteed. This contribution considers the concept and the algorithms for checking the consistency and the correctness of the process structure