Die doppeltverkettete Streuung von mehrphasigen Mehrlochwicklungen mit Durchmesserschritt

Zusammenfassung Für verschiedene Phasen- und Lochzahlen je Pol und Phase sind die Werte der abgeleiteten Beziehung, die auch für Phasenzahlen kleiner als 1 ihre Gültigkeit behält, in einer Tafel zusammengestellt. In Anbetracht der Vorteile von vielphasigen Wicklungen wird eine 12phasige Schaltung für 3phasigen Netzanschlu\ angegeben.Mit Rücksicht auf die Wichtigkeit für die Berechnung der Drehmomente von Oberfeldern sind für den Käfiganker die Werte der doppeltverketteten Streuung in Abhängigkeit von den Phasenzahlen (m=0,3 bis 40) in Kurvenform dargestellt. Diese gelten auch für die sogenannten oberfeldarmen Wicklungen, bei denen die Phasenzahl durch Kunstschaltungen soweit erhöht wird, da\ nur mehr die Lochzahlq=1 verbleibt.Bezeichnungen m Phasenzahl des Strombelages - q Stabzahl je Polpaar und Phase - _d Koeffizient der doppeltverketteten Streuung - Ordnungszahl der Stäbe je Pol und Phase - Ordnungszahl der Phasen - v Ordnungszahl der Oberfelder - Abszisse des ersten Stabes der ersten Phase (Bogenma\) - x Abszisse der Feldkurve in elektrischen Graden - zeitlicher Phasenwinkel des Stromes der ersten Phase ( elektr.) - p Polpaarzahl - y Ordinate der Feldkurve - y ₁ Amplitude der Grundwelle - _v Amplitude desv-ten Kosinusgliedes - b _v Amplitude desv-ten Sinusgliedes - Z Zähnezahl des Käfigläufers     

CFD simulations of hydrogen combustion in a simplified EPR containment with CFX and REACFLOW

The prediction of over-pressures and temperatures that are generated by hydrogen explosions in case of a severe nuclear accident is a crucial stage of the safety analysis of the containment. The investigation presented in this paper is a continuation of the numerical studies of validation and benchmarking that were carried out in the European co-sponsored project HYCOM. In the present work, numerical simulations of hydrogen deflagrations within a simplified, real-scale European Pressure Reactor (EPR) containment have been performed with two CFD codes, CFX4 and REACFLOW. The analysis has been focused not only on overpressure peaks and pressure oscillations, but also on pressure differences between the two sides of the same wall of internal compartments. Different geometrical configurations have been considered in term of presence of vents between internal compartments and in term of vents number, size and position. Single and multiple ignition points have also been taken into account. The paper describes the main results of the investigation and it is a demonstration of how CFD modelling can provide significant indications for real-scale safety applications within the limits of uncertainty of the accident scenarios.     

NanoSIMS: Insights into the Organization of the Proteinaceous Scaffold within Hexactinellid Sponge Spicules

The giant basal spicules (GBS) from Monorhaphis chuni (Porifera [sponges], Hexactinellida) represent the largest biosilica structures on Earth and can reach lengths of 300 cm (diameter of 1.1 cm). The amorphous silica of the inorganic matrix is formed enzymatically by silicatein. During this process, the enzyme remains trapped inside the lamellar‐organized spicules. In order to localize the organic silicatein scaffold, the inside of a lamella has been analyzed by nano‐secondary ion mass spectrometry (NanoSIMS). It is shown that the GBSs are composed of around 245 concentrically arranged individual siliceous lamellae. These surround an internal siliceous axial cylinder. The lamellae adjacent to the cylinder are thicker (10–30 μm) than the more peripheral lamellae (2–10 μm). One lamella of a thickness of 18 μm has been selected for further analysis. This lamella itself is composed of three sublamellae with an individual thickness of 2–6 μm each, which are then further organized into three cylindrical slats (thickness: 1.6–1.8 μm). Other than the main lamellae, the sublamellae are not separated from each other by gaps. The element analysis of the sublamellae by NanoSIMS revealed that the siliceous matrix is embedded in an organic matrix that consists of up to 6–10 wt/% of C. The pattern of C distribution reflects a distinct zonation of the organic material within the solid intralamellar biosiliceous material. A growth model for the lamella starting from nanosized silica particles is proposed: During formation of a lamella nanosized silica particles fuse, through biosintering processes, to slats that build the individual sublamellae, which then finally form the lamellae. In turn, those lamellae may form the higher structural entity, the axial cylinder.     

Histological technique to detect the physiological age of the malaria vector mosquito Anopheles pharoensis (Diptera: Culicidae)

The risk of malaria recurrence increases due to the main vector, Anopheles pharoensis. The physiological age of the mosquito population is needed to expect malaria vector dynamics. The number of completed gonotrophic cycles is of great importance in determining the physiological age of females. A technique has been described that focuses on the number of dilatations remaining in the ovarioles after each oviposition to determine how many blood meals have been taken. At each gonotrophic cycle, the chances of infection of the vectors are repeated. The histological changes that occur immediately in the ovarioles and ovulation itself were studied. Under the influence of the contractions of the ovarian muscles, the eggs begin to move over the distal end of the ovariole into the inner oviduct. The terminal pedicle is markedly dilated near the diameter of the eggs. After the expulsion of the mature eggs, ovariole dilations were found at the point of their development in the terminal pedicle due to the accumulation of nurse cell remnants and follicular epithelium. The results were used to develop epidemiological localization and to evaluate the effectiveness of antimalaria interventions. The ovarian inspection often provides a technique to distinguish nulliparous from parous female anophelines. In addition, this study can provide basic entomological knowledge on the physiological age of mosquitoes by considering the histological changes in the ovaries, which allow the evaluation of vector management strategies in the field.     

Removal of copper(II) and cadmium(II) ions from aqueous solutions by biosorption onto pine cone

In this study, the removal of copper(II) and cadmium(II) ions from aqueous solutions by biosorption onto pine cone was studied. Variables that affect the biosorption process such as pH, biosorbent dosage, initial metal ion concentration, contact time and temperature of solution were optimized. Experimental data were fitted to Langmuir, Freundlich, Dubinin Radushkevich and Temkin isotherm models to investigate the equilibrium isotherms. Pseudo-first-order, pseudo-second-order and intraparticle diffusion kinetic models were used to determine the biosorption mechanism. The thermodynamics of biosorption were studied for predicting the nature of biosorption. Experimental results showed that pine cone could be evaluated as an alternative precursor for removal of heavy metal ions from aqueous solutions, due to its high biosorption capacity, availability, and low cost.     

Hydro-economic Modeling in River Basin Management: Implications and Applications for the European Water Framework Directive

Economic ideas and processes are becoming increasingly integrated with more traditional engineering and hydrologic models of water management problems. Combining economic management concepts and performance indicators with an engineering-level of understanding of a hydrologic system can provide results and insights more directly relevant for water management decisions and policies. When such models are developed and used with involvement of stakeholders, they can become a basis for shared understanding of water problems as a foundation for negotiated management and policy solutions. When implemented with optimization software, integrated hydro-economic models also can suggest promising innovative solutions for policy-makers to consider. Their applications to river basin management problems are reviewed. Economic and integrated economic-engineering-hydrologic modeling is then discussed in the context of the evolving European Water Framework Directive. Relevant items are cost recovery and water pricing, cost-effectiveness of water management measures, and public participation in decision processes.     

Detection of colorectal adenoma and cancer based on transthyretin and C3a-desArg serum levels

Colorectal cancer is the second leading cause of cancer death, and it develops from benign colorectal adenomas in over 95% of patients. Early detection of these cancer precursors by screening tests and their removal can potentially eradicate more than 95% of colorectal cancers before they develop. To discover sensitive and specific biomarkers for improvement of pre‐clinical diagnosis of colorectal adenoma and cancer, we analysed in two independent studies (n = 87 and n = 83 patients) serum samples from colorectal cancer (stage III), colorectal adenoma and control patients using SELDI‐TOF‐MS. Extensive statistical analysis was performed to establish homogeneous patient groups based on their clinical data. Two biomarkers that were each able to distinguish control patients from either colorectal adenoma or colorectal cancer patients (p<0.001) were identified as transthyretin (pre‐albumin) and C3a‐desArg by MS/MS and were further validated by antibody‐based assays (radial immunodiffusion, ELISA). A combination of both proteins clearly indicated the presence of colorectal adenoma or carcinoma. Using a cut‐off of <0.225 g/L for transthyretin and >1974 ng/mL for C3a‐desArg, we found a sensitivity and specificity for colorectal adenoma of 96% and 70%, respectively.     

Rationalisierung des Zeichnungswesens im Chemie-Apparatebau

Rationalizing drawings for chemical apparatus . For small and medium-sized manufacturers of apparatus, producing drawings may constitute a disproportionate waste of time and personnel, particularly when no new designs are involved but only modification or improvement of drawings supplied by the customer. One possibility for rationalizing drawing is to simplify the old-fashioned approach by using symbols for frequently drawn or standard items, or by listing alphanumerically. This presumes a kind of systematization permitting determination of those symbols and their reasonable use, as well facilitating rationalization by means of data processing. There are different approaches to computer-aided drawing (from computer controlled drawing-board to interactive screens); here a CAD programme is presented which was especially developed for graphic presentation of chemical apparatus, and which can be used without learning a programming language.