Umwelt und Entwicklung Beiträge der Privatwirtschaft insbesondere im Bereich der Umwelt- und Raumplanung

Einleitung In diesem Artikel geht es darum, darzustellen, welche Probleme sich im Umweltbereich in den Ländern der Dritten Welt stellen und welche Beiträge Schweizer Ingenieure und Berater zur Lösung dieser Probleme leisten können. Die Ausführungen dienen dem Anliegen dieser Schrift, die bestehenden Aussenbeziehungen unseres Landes sichtbar zu machen und Hinweise auf mögliche weitere Aufgabenfelder zu geben. Problemstellungen in der Dritten Welt Um das Wesentliche nicht aus den Augen zu verli..

Umwelt und Entwicklung Beiträge der Privatwirtschaft insbesondere im Bereich der Umwelt- und Raumplanung

Einleitung In diesem Artikel geht es darum, darzustellen, welche Probleme sich im Umweltbereich in den Ländern der Dritten Welt stellen und welche Beiträge Schweizer Ingenieure und Berater zur Lösung dieser Probleme leisten können. Die Ausführungen dienen dem Anliegen dieser Schrift, die bestehenden Aussenbeziehungen unseres Landes sichtbar zu machen und Hinweise auf mögliche weitere Aufgabenfelder zu geben. Problemstellungen in der Dritten Welt Um das Wesentliche nicht aus den Augen zu verli..

Surface plasmon resonance sensor showing enhanced sensitivity for CO2 detection in the mid-infrared range

We present the first optical sensor based on Surface Plasmon Resonance (SPR) operating in the mid-infrared range. The experimental setup is based on a Kretschmann geometry with Ti/Au layers deposited on a CaF2 prism where light excitation is provided by a Quantum Cascade Laser (QCL) source. Evidence of SPR is presented and the sensing capability of the system is demonstrated by using CO2 and N2 mixtures as test samples. Due to the absorption of CO2 at this wavelength, it is shown that the sensitivity of this configuration is five times higher than a similar SPR sensor operating in the visible range of the spectrum. © 2008 Optical Society of America OCIS codes: (240.6680) Surface plasmons; (280.4788) Optical sensing and sensors; (040.3060) Infrared; (140.5965) Semiconductor lasers, quantum cascade; (250.5403) Plasmonic

Geometrische Optimierung eines 3-Finger-Greifers

Zusammenfassung: Abhängig von der Form des zu greifenden Objektes und einer vorgegebenen Handkonfiguration (Länge der 4 Fingerglieder, Handfläche, Abstand der beiden Finger vom Daumen) werden verschiedene Möglichkeiten, das Objekt zu umfassen (z.B. nur mit einem Finger oder mit der ganzen Hand, ...), betrachtet. Berechnet und auf Drucker oder Bildschirm ausgegeben werden minimale und maximale Greifräume einer Hand sowie die Berührungspunkte des Objektes und Gelenkauslenkungen (= Winkel) der einzelnen Fingerglieder

Messwerterfassungseinheit eines Niederfrequenz-Messplatzes

Zusammenfassung: Für einen NF-Meßplatz wurde eine Meßwerterfassungseinheit entwickelt, die Eingangsspannungen von 10Hz - 40kHz, 0.7mV - 100V auf 10V Amplitude verstärkt bzw. abschwächt. Von diesem Signal werden wahlweise Spitzen oder Effektivwert gemessen und als 12-Bit-A/D-gewandelte Werte an einen IBM-kompatiblen Rechner weitergegeben

Process Control For Ozonation Systems: A Novel Real-Time Approach

For real-time control of ozonation processes in water works, a sequencing batch reactor was constructed to measure the ozone decay rate constant (k(O3)) in short time intervals of about 15 min. The batch reactor is filled during the production process, immediately after dissolving ozone in water by a static mixer. On the basis of k(O3) and the initial ozone concentration ([O-3](0)), and the experimentally determined ratio of the concentrations of (OH)-O-center dot radicals to ozone (R-ct), the degradation of micropollutants in ozone reactors (modeled as Continuously Stirred Tank Reactors - CSTRs) were calculated for compounds with known reaction rate constants with ozone and (OH)-O-center dot radicals. Calculated degradation of atrazine, iopromide, benzotriazole and acesulfame are in good agreement with measured data. For acesulfame the following rate constants were determined in this study at 20 C-o: reaction rate constant with ozone = 88 M(1)s(1), reaction rate constant with (OH)-O-center dot radical = 4.55x10(9) M(1)s(1). For the ozone reaction an activation energy of 35 kJ/mol was determined. Similarly to micropollutants, the relative inactivation of microorganisms (N/N-0) can be calculated based on the inactivation rate constant for ozone and if applicable the lag phase. The pI-value (=logN/N-0) was introduced and implemented in the process management system to calculate online the log inactivation of reference microorganisms such as B. subtilis spores. The system was tested for variation of pH (6.58.5), DOC (1.24.2 mg/L) flowrate 3.212 m(3)/h and temperature (5.79 C-o). Furthermore, a given pI-value, e.g. 1 for a 1-log inactivation of B. subtilis spores, can be set as control parameter in the process management system. The ozone gas flow is then adjusted until the set pI-value is reached. The process control concept was validated with B. subtilis spores. Generally, a good agreement was found between calculated and measured inactivation data. It was also demonstrated, that a constant ozone residual may lead to insufficient disinfection or overdosing of ozone. The new process control concept for ozonations based on onsite measurement of the ozone decay rate constant and the pI-value allows to assess disinfection and degradation processes quantitatively in real-time

Possible New Strategies for the Treatment of Congenital Hyperinsulinism

Objective Congenital hyperinsulinism (CHI) is a rare disease characterized by persistent hypoglycemia as a result of inappropriate insulin secretion, which can lead to irreversible neurological defects in infants. Poor efficacy and strong adverse effects of the current medications impede successful treatment. The aim of the study was to investigate new approaches to silence β-cells and thus attenuate insulin secretion. Research Design and Methods In the scope of our research, we tested substances more selective and more potent than the gold standard diazoxide that also interact with neuroendocrine ATP-sensitive K+ (KATP) channels. Additionally, KATP channel-independent targets as Ca2+-activated K+ channels of intermediate conductance (KCa3.1) and L-type Ca2+ channels were investigated. Experiments were performed using human islet cell clusters isolated from tissue of CHI patients (histologically classified as pathological) and islet cell clusters obtained from C57BL/6N (WT) or SUR1 knockout (SUR1-/-) mice. The cytosolic Ca2+ concentration ([Ca2+]c) was used as a parameter for the pathway regulated by electrical activity and was determined by fura-2 fluorescence. The mitochondrial membrane potential (ΔΨ) was determined by rhodamine 123 fluorescence and single channel currents were measured by the patch-clamp technique. Results The selective KATP channel opener NN414 (5 µM) diminished [Ca2+]c in isolated human CHI islet cell clusters and WT mouse islet cell clusters stimulated with 10 mM glucose. In islet cell clusters lacking functional KATP channels (SUR1-/-) the drug was without effect. VU0071063 (30 µM), another KATP channel opener considered to be selective, lowered [Ca2+]c in human CHI islet cell clusters. The compound was also effective in islet cell clusters from SUR1-/- mice, showing that [Ca2+]c is influenced by additional effects besides KATP channels. Contrasting to NN414, the drug depolarized ΔΨ in murine islet cell clusters pointing to severe interference with mitochondrial metabolism. An opener of KCa3.1 channels, DCEBIO (100 µM), significantly decreased [Ca2+]c in SUR1-/- and human CHI islet cell clusters. To target L-type Ca2+ channels we tested two already approved drugs, dextromethorphan (DXM) and simvastatin. DXM (100 µM) efficiently diminished [Ca2+]c in stimulated human CHI islet cell clusters as well as in stimulated SUR1-/- islet cell clusters. Similar effects on [Ca2+]c were observed in experiments with simvastatin (7.2 µM). Conclusions NN414 seems to provide a good alternative to the currently used KATP channel opener diazoxide. Targeting KCa3.1 channels by channel openers or L-type Ca2+ channels by DXM or simvastatin might be valuable approaches for treatment of CHI caused by mutations of KATP channels not sensitive to KATP channel openers