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The precipitation of heavy metals as hydroxides is the standard technique for the decontamination of waste water streams polluted by these elements. On the other side, progress in research has been made concerning the biosorption onto dead biomass and bioprecipitation supported by physiologically active bacteria. As the aim of this study, a flexible strategy has been envisaged cleaning a waste water with definite heavy metal load underlying the process mentioned above. Suitable bacteria were enriched and the process was tested in a technical plant. As result, a very high efficiency of heavy metal elimination has been found. The field of application covered by the acquired process is identical with the whole range of the waste water streams polluted by heavy metals. In addition, a second stage may be necessary if there are any further contaminants to be removed. (orig.) [Deutsch] Bei der Reinigung von schwermetallhaltigen Abwaessern ist der derzeitige Stand der Technik gegeben durch die ...

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The paper presents fundamental studies on natural biosorption to algae of heavy metals. The investigations were carried out by TU Berlin University in a special research project (Sfb 193, 'Biologische Behandlung industrieller und gewerblicher Abwaesser'). The chlorophyceae C. vulgaris was used as reference alga, and 38 further algae were analzyed with regard to their sorption characteristics for lead, cadmium, nickel and zinc. The most effective algae were the chlorophyceae C. salina, the cyanophyceae S. hofmani and L. taylorii. The biosorption characteristics of C. salina and L. taylorii were investigated in detail. L. taylorii was found to be exploitable successfully in a technical process, so the investigations were extended to include copper. Knowledge about the chemical processes of biosorption is important for any attempt to modify the biosorption characteristics. Experiments on the incorporation of additional functional groups in the cell wall polysaccharides ...

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The further optimisation and improvement of the efficiency of internal combustion engines require the realisation of new technologies leading to a distinctively faster warm-up behaviour of the coolant and lubricants as well as of the engine components after a cold start. In order to achieve reduced fuel consumption and exhaust gas emissions with the help of heat management, the design criteria of innovative cooling systems need to be reflected and adapted to future requirements. The use of intelligent components within the cooling system, such as the 'Stand Alone Rotary Valve' as a thermostat's substitute or the use of coolant pumps with a rotary valve integrated into the pump's inlet chamber, offer new ways to realise in a decisively quicker and more flexible way the appropriate heating up and cooling down procedures at varying driving conditions. A description of both of the intelligent components for the cooling system is given in this paper. The ...

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Osteonecrosis (ON) of the hip joint remains an unsolved therapeutical problem. Diagnosis of ON of the hip has been improved by the technical progress of imaging modalities and better understanding pathomorphology. Over a long period only plain radiographs have been available. Scintigraphy and computed tomography contributed to differential diagnosis and early detection of bone necrosis. Diagnosis in an early reversible stage is of importance. Understanding of pathophysiology, early diagnosis and therapeutical approach has been significantly improved by MR imaging. Using the ARCO system all imaging modalities and their diagnostic viability are described in the five ARCO stages. At the end a diagnostic algorithm will be proposed. (orig.) [German] Die Osteonekrose des Hueftgelenks (ON) stellt noch immer ein nicht geloestes therapeutisches Problem dar. Die diagnostischen Moeglichkeiten bei der ON wurden in den letzten Jahren durch technische Fortschritte bei den bildgebenden Verfahren und ...

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Turbine sets are inspected at their overhaul intervals throughout their operating lives. Using three examples, the present article describes the procedure in the inspection and assessment of steam turbines during overhauls and also deals with rehabilitation measures. In addition to the usual non-destructive tests and the recording of findings, computational life assessments are also considered. (orig.) [Deutsch] Turbosaetze werden waehrend ihrer Betriebszeit anlaesslich von Revisionen ueberprueft. Anhand von drei Beispielen wird in diesem Beitrag die Vorgehensweise bei der Pruefung und Bewertung von Dampfturbinen bei Revisionen und fuer Rehabilitationsmassnahmen dargestellt. Neben ueblichen zerstoerungsfreien Pruefungen und Befundaufnahmen erfolgten in Verbindung damit auch rechnerische Lebensdauerbewertungen. (orig.)

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This conference of Deutsche Wissenschaftliche Gesellschaft fuer Erdoel, Erdgas und Kohle focused on energetic utilisation and recycling of waste materials and biomass, i.e. combustion, gasification and pyrolysis. Aspects of process control were gone into as well. [German] Die Fachbereichstagung der Deutschen Wissenschaftlichen Gesellschaft fuer Erdoel, Erdgas und Kohle beschaeftigte sich mit der energetischen und stofflichen Nutzung von Abfall und Biomasse. Verbrennung, Vergasung und Pyrolyse verschiedener Abfallstoffe sowie die Prozesssteuerung wurden eroertert.

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A model for combined mass and heat transfer during nonisothermal gas absorption in a two-phase gas- liquid bubbly medium with a high gas content and/or large times of gas-liquid contact is suggested. Diffusion and thermal interactions between bubbles is taken into account in the approximation of a cellular model of a bubbly medium whereby a bubbly medium is viewed as a periodic structure consisting of identical spherical cells with periodic boundary conditions at a cell boundary. Distribution of concentration of dissolved gas, temperature distribution in liquid and coefficients of mass and heat transfer during nonisothermal absorption of a soluble pure gas from a bubble by liquid are determined. In the limiting case of absorption without heat release the derived formulas recover the expressions for isothermal absorption. (orig.). With 1 fig., 1 tab. [Deutsch] Es wird ein Modell vorgestellt, das den kombinierten Waerme- und Stoffaustausch waehrend der ...

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LP steam turbine retrofits are generally undertaken as a result of mechanical problems, for example due to stress corrosion cracking, torsional vibration or erosion. They present plant operators with an opportunity to introduce advanced aerodynamic technology, and at the same time improve efficiency and availability. Standard components, the majority proven in long-term service, can be used to obtain a permanent solution to the problems. In several European countries, retrofits have been carried out on intact LP steam turbines owned by utilities whose primary motivation is efficiency improvement. (orig.) [Deutsch] Niederdruck-Dampfturbinen werden in der Regel nur dann nachgeruestet, wenn waehrend des Betriebes Probleme durch Spannungsrisskorrosion, Torsionsschwingungen oder Erosion auftreten. In solchen Faellen bietet sich die Gelegenheit, eine moderne aerodynamische Loesung zu waehlen, die gleichzeitig Wirkungsgrad und Verfuegbarkeit verbessert. Es wird gezeigt, ...

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Plasma Immersion Ion Implantation (PIII) is a new hybrid technology for surface treatment of materials based on the principles of plasma nitriding and ion implantation. The equipment and the operation of the system are introduced. As well as providing an alternate method of ion implantation, it is possible to combine energetic ion bombardment with plasma nitriding. Different metal materials and treatment conditions have been studied. The capability of PIII-treatment to improve the properties of a wide range of metals has been proven. Application for forming tools and their industrial test has been successful. (orig.) [Deutsch] Die Plasmaimmersionsimplantation (PIII) ist eine neue Hybridtechnologie zur Behandlung von Werkstoffoberflaechen und basiert auf den Prinzipien des Plasmanitrierens und der Ionenimplantation. Die Anlagentechnik und die Arbeitsweise werden vorgestellt. Verfahrensspezifische Vorteile entstehen durch die Moeglichkeit, sowohl alternative Ionenimplantationen als auch ...

British Library Electronic Table of Contents (United Kingdom)

Zusammenfassung Hintergrund Die vorliegende Arbeit untersucht, welche Frequenzkombination f?r die Berechnung der mittleren H?rverluste im Tonschwellenaudiogramm am besten mit dem H?rverlust f?r Zahlen im Sprachaudiogramm korreliert, da in der Literatur verschiedene Rechenvarianten f?r diese gutachterliche Plausibilit?tspr?fung beschrieben werden. Es wurden die 3?Rechenvarianten A (250, 500 und 1000?Hz), B (500 und 1000?Hz) und C (500, 1000 und 2000?Hz) verglichen. Methoden Die Audiogramme von 80?Normalh?rigen, 106?Schwerh?rigen und 135 zu Begutachtenden wurden retrospektiv analysiert. Die Differenzen der Mittelwerte aus dem Tonschwellenaudiogramm und dem H?rverlust f?r Zahlen wurden f?r das rechte und linke Ohr getrennt in den 3?Patientenkollektiven berechnet und statistisch verglichen. Er...

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After 3 years of construction the trial run of the heating power station HKW 2 ended in November 1997 on time. No extraordinary damage occured during construction, assembly or commissioning. The plant has been operating according to schedule since November 1997. A brief inspection carried out in the summer of 1998 in order to assess warranty claims showed no damage to any part except one valve. Experience shows that all aforementioned activities were necessary. The paper reports about success and negative experience. Certification according to DIN EN ISO 9000ff., however, affords to guarantee of high-quality construction. Builders of such plants therefore need to set up their own quality assurance centre and ensure its technical competence. If necessary,additional experts should be called in.Quality assurance costs for HKW 2 came to about 0.5-0.6 percent of total costs. In view of the success and long life of this investment these expenses are more than justified. (orig.) [German] Nach ...

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The aim of this work was the examination of the coarse grain recrystallisation of the {gamma}-free ODS nickel-based alloy PM 1000 depending on the various parameters due to the processing during heat treatment. After isotropic hot compacting (HIP) of the mechanically alloyed powder, one observes a homogeneous sub-microscopic fine grain structure which can coarsen during high temperature heat treatment, due to sufficiently high driving force from the grain boundary energy via abnormal grain growth to 600 times its size. The setting of the elongated high temperature resistant recrystallisation structure is, however, not connected with this. The dependence of the sucess of re-crystallisation on the re-forming parameters (re-forming temperature and degree of re-forming) was shown by a socalled re-forming card. In order to achieve re-crystallisation to a coarse and aligned grain structure, apart from a certain absolute minimum degree of re-forming, the re-forming must occur within a defined ...

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This report describes work carried out in the context of TurboTech Interim for the development of a system for monitoring stationary gas turbines for approaching the stability limit of the compressor. The requirements for the system components were defined and the suitability of different types and positions of pressure sensors were examined and evaluated. It was found very early in the work that, due to the complexity of the object being monitored, one would not succeed in finding a simple criterion for monitoring the pump limit. Rather, apart from the selection of suitable sensors and optimum positions, one must analyse the present signals in different ways and create a decision matrix from this. Existing work on this subject is mostly concerned with the phenomena in the context of experiments on experimental compressors or is not suitable for the requirements of stationary industrial gas turbines. The project is being carried out in the context of TurboTech II with the main aims of: ...

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In a case study of the River Lahn, Hessen, Germany, the ecological impact of effluents from sewage treatment plants was investigated. These emissions have a significant impact on the receiving water quality with ammonia, nitrite, phosphorus and the eutrophication as most important factors. Current legislation standards seem to be sufficent for the sanitation of the nitrogen load. The potential of phosphorus removal in sewage treatment plants however may not reach the demand for eutrophication abatement. Therefore, integrated and immission oriented strategies are required including in site measures of river restoration. (orig.) [Deutsch] An der hessischen Lahn wurde in einem mehrjaehrigen Forschungsvorhabens die Bedeutung von Abwasserereinleitungen aus Klaeranlagen hinsichtlich ihrer gewaesseroekologischen Relevanz untersucht. Wesentliche Belastungen beziehen sich auf die Parameter Ammonium, Nitrit und Phosphor sowie eutrophierungsbedingte Folgeerscheinungen. ...

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The ash of biomass fuels was analysed in order to identify its inorganic chemical characteristics. The experiments were carried out using different methods of extraction. The accuracy of the measurements was verified by comparative analyses using certified samples. The composition was shown to vary with the fuel type and ash fraction. In the case of arsenic and the toxic heavy metals cadmium, mercury and lead, accumulation factors of 1.4 to 43 were measured in the tissue filter ash. [German] Fuer die Bestimmung der stofflichen Eigenschaften von Biobrennstoffaschen werden neben der fuer die Ermittlung von Stoffbilanzen notwendigen Analyse der Gesamtgehalte, in Abhaengigkeit von der Zielsetzung und den gesetzlichen Vorgaben, unterschiedliche Extraktionsverfahren eingesetzt. Fuer die Gesamtgehaltsbestimmung wurden aus laborinternen Wiederholungsuntersuchungen sowie einem laborexternen Analysenvergleich Kenngroessen fuer die Praezision und Richtigkeit abgeleitet. ...

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The results of the creep performance studies at temperatures from 700-1000 C with welds of alloy 800 HT, the manual shielded metal arc welds made with Githerm 85 and Grini 209 filler metals, as well as the MIG pulsed arc welds made with the Nicrofer S 206 and Nicrofer S 5520 filler metals, proved to be in very good agreement with the calculated characteristic values published on VdTUeV sheet 434 in comparative assessments based on creep values valid for a service period of 10 000 hours. The MIG pulsed arc weld made with the Nicrofer S 5520 filler metal achieved by far the best results and strength values comparable to those of the base material, whereas the values of the other welds were corresponding to calculated strength values of the base material reduced by 20%. (orig./CB) [Deutsch] Die im Temperaturbereich von 700-1000 C an Alloy 800 HT und den Elektrodenhandschweissverbindungen mit den Schweisszusaetzen Gritherm 85 und Grini 209, sowie den MIG-Pulsed-Arc-Schweissungen mit den ...

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Based on the first part of this report the molybdenum loadings of the red mud were varied and the activity of the catalytic additives was tested in a batch autoclave with TJP VR. The 30% Molybdenum loading (sample Nr. 6) was found to be optimum. Further testing with two vacuum residues (TJP VR and ARH VR) and sample Nr. 6, indicates the influences of the process parameters for hydrogen pressures of 9-15 MPa, temperatures of 440-475 C and residence times of 0-60 min. Obviously 440 C, 12 MPa and a residence time of 30 min are best conditions for hydrocracking of both vacuum residues with sample Nr. 6. (orig.) [Deutsch] Beruhend auf dem ersten Teil des Berichtes wird der Belegungsgrad der Rotmasse mit Molybdaen variiert und die resultierenden katalytischen Zusaetze werden in einem Autoklaven mit TJR VR getestet. Ein Belegungsgrad mit 30% Molybdaen (Probe 6) scheint optimal zu sein. Mit diesem Zusatz werden die Einfluesse der Prozessparameter bei Wasserstoffkaltdruecken zwischen 9 und 15 ...

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Borehole stability is affected to a significant extent by the 3D local and regional stress field. Preliminary information on underground stress fields is provided by the World Stress Map, which shows N-NW stress at a depth of about 5000 m for the Voelkersen field. Earlier data analyses showed various directions in the range of 310-360 degrees. This was assumed to be a methodical error. An extensive study was carried out to evaluate and interpret all relevant information provided by borehole tests, borehole logs, and drill core measurements. [German] Standsicherheit und Stabilitaet von Bohrungen werden ganz wesentliche beeinflusst durch das umgebende dreidimensionale lokale und regionale Spannungsfeld. Fuer die Planung zukuenftiger (horizontaler) Bohrungen und die Erzeugung kuenstlicher Risse (''fracs'') spielt das Spannungsfeld eine bedeutende Rolle. Erste Hinweise ueber das regionale Spannungsfeld im Untergrund gibt die World Stress Map, in der ...

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Blades of modern steam turbines are designed for high efficiency and operational safety. Modern computer programs enable optimisation of design but factors like manufacturing, assembly, operation and downtimes still play an important role. Damage statistics show that blade damage still quite frequent. Selected cases from the Allianz damage assessment centre show some of the more frequent damage mechanisms. Damage is often caused when several factors come together. Prevention of follow-up damage requires early identification of beginning damage.(orig.) [German] Die Auslegung der Beschaufelung moderner Dampfturbinen hat die Vorgabe, einen hohen Wirkungsgrad bei gleichzeitig hoher Betriebssicherheit zu erreichen. Mit den heute zur Verfuegung stehenden Rechenprogrammen ist eine entsprechende Optimierung realisierbar. Fuer die langzeitige Betriebsbewaehrung haben aber Einflussgroessen aus Fertigung, Montage, Betrieb und Stillstand auch heute noch die gleiche Bedeutung wie in der ...

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For location of leakage at district heating pipelines several techniques are available today. If there is no wire bound lead monitoring system installed, the DH company has to apply mobile methods for detection and location and if possible characterization of leakage. Most mobile methods available today are restricted in application and often they cause supply disconnections, especially the location of very small leaks is difficult. The Institute for Environmental, Safety and Energy Technology (UMSICHT) has tested a new developed method that can be executed by own employees of DH companies that can be realised parallel to normal supply mode, and that is able to locate and characterize even very small leakages. (orig.) [Deutsch] Zur Lecksuche an Fernwaermeleitungen stehen verschiedene Techniken zur Verfuegung. Wurde beim Bau der Fernwaermetrasse kein drahtgebundenes Ueberwachungssystem eingebaut, ist der Netzbetreiber auf mobile Lecksuchmethoden angewiesen. Die ...

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Water power plants mean the design, configuration, execution and operation of buildings and of hydraulic and electrical machines. Their many types are due to the stages of development and the technical alternatives of the use of waterpower and the associated energy economy aspects. The main points of this work are the use of water power, different hydro-electric powerstations, water collection, machines and electrotechnical equipment. In the 2nd revised edition parts on electrical engineering, environment, minimum water run-off pumped storage plants, small scole plants, economical aspects and finite elements were broadened. It is a comprehensive textbook and technical book for students of civil engineering and particularly suitable for engineers active in the theory and practice of waterpower construction. (orig./GL) [Deutsch] Wasserkraftanlagen bedeuten Planung, Gestaltung, Ausfuehrung und Betrieb von Bauwerken und hydraulischen sowie elektrischen Maschinen. Ihre Typenvielfalt ...

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Experts tend to disagree about the economic effects of air pollution abatement measures. This book, which addresses also non-experts, explains the analytical background on the basis of available data. The authors conclude that there is a wide range of political options for achieving the goal of air pollution abatement. They differentiate between the various levels of discussion and show how misinterpretations of scientific results come about, thus making an important contribution to a discussion that is based on facts rather than emotions. [German] Die Einschaetzungen zur wirtschaftlichen Bewertung von Klimaschutzmassnahmen, insbesondere zur Steigerung der Energieeffizienz, sind sehr widerspruechlich. Dieses Buch erlaeutert anhand von Zahlenmaterial die analytischen Hintergruende und ist auch fuer Nicht-Oekonomen verstaendlich geschrieben. Die Autoren kommen zu dem Schluss, dass in vielen Bereichen rentable Energiesparpotentiale nicht erkannt und umgesetzt werden. Sie zeigen, dass die ...

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Purpose: To determine the value of MRI in the postoperativ evaluation of a singular ventricle compared to echocardiography and cardiac catheterization. Materials and methods: Thirty-one patients (range: 6 months to 30 years) with a functional single ventricle following palliative corrective operations. Five patients had a Blalock-Taussig-Shunt, 8 patients a Glenn-Anastomosis and 18 a cavopulmonary shunt (6 with classic Fontan-Circulation, 12 with modified cavopulmonary anastomosis). The results in terms of postoperative morphologic changes were compared to percutaneous echocardiography (31/31) and cardiac catheterization (6/31). Results: Echocardiography, which was performed on all patients, could not visualize the entire length of the tunnel, the Glenn-Anastomosis or the central pulmonary arteries in 70% of the patients due to an inadequate acoustic window. MRI was able to show the entire tunnel in 11/12 patients and the central pulmonary arteries in 30/31 patients. The exact anatomy ...

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Purpose: In vitro evaluation of possible deflection and heating of present-day prosthetic heart valves, 12 technical and 5 biological, were investigated using a 1.5 Tesla Siemens Vision system. Deflection was measured at the edge of a 1.5 Tesla superconducting magnet. Each valve was then submerged in a vial of a 1/1 electrolyte solution and temperature was measured before and after imaging with a turbo-spin-echo sequence (TR 5200 ms, TE 138 ms, Flip angle 180 C, acquisition time 10.5 minutes, length of echo train 29). MR imaging was performed with phase encoding parallel and perpendicular to the plane of the valves. Results: None of the investigated prosthetic heart valves was deflected. The maximal observed temperature rise was 0.5 C. During MR investigation of the prostheses, artifacts caused by metallic parts were less evident using a spin-echo sequence than a gradient-echo sequence. Conclusions: Patients with the tested present-day prosthetic heart valves can be safely imaged by ...

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To determined precisely a possible connection between the amount of copper in tap-water and the risk of early childhood liver disease, it was attempted through an epidemiological survey, to determine the extent of excessive concentrations of copper in the tap-water of households with copper pipes. Water samples from 956 households were tested for copper, and the state of health of the infants in these households was documented. Infants who had been fed using water with a copper concentration of 0.8 mg/l or more received a paediatric examination with a blood serum analysis to rule out any liver damage. A copper level greater than 0.8 mg/l was found in only 2% of the households examined. Eight infants were examined by a paediatrician and their serum was analysed. These infants had either been breast-fed to the 12th week or had received more than 200 ml of tap water per day during first 12 months. None of the infants examined showed any signs of liver malfunction. From the results of the ...

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1. Cyanide degradation: Of the cyanide- and thiocyanate-degrading bacteria, Burkholderia cepacia and Pseudomonas spec. were the most effective. 2. Biosorption: Of the isolates suited for biosorption of heavy metals, 597-A (non-identifiable) and 597-A2 (Aspergillus fumigatis) had the biggest potential. The sorption capacity of the fungi for metals varied with the C source used for their growth: apple juice > molasses > glucose. The fungi are not cyanide-sensitive and can even degrade cyanide. Living biomass had better metal sorption efficiencies than dead mycelium. The biosorption rates in waste water were usually higher than in broth. Depending on the metal composition and concentrations and on the exposure time and volume of the mycelia, up to 85 % of the initial concentration was removed from the liquid phase. The capacity of different biomasses for the sorption of metal mixtures was between 65 and 80 mg/g of dry matter depending on the experimental conditions, with ...

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On the basis of cylindrical roller thrust bearings it was systematically examined to what extent PVD-coatings are able to take over the function of EP/AW-additives. The bearings were tested under heavy-duty conditions in order to distinguish very fast the efficiency of different coating-substrate-systems. Several coatings were tested for their ability to protect an un-coated counterpart. So just the washers of the roller bearings were coated, the rollers stayed un-coated. Four Me-C:H-coatings showed the best performance and fulfilled the required criterion for roller bearings in the boundary friction: low loss of mass and hardly surface deviation. Material carryover from the carbonaceous coating to the 100Cr6 steel surface was developed by the Me-C:H-coatings during the tests. This mechanism was able to protect the un-coated rollers. Closer investigations were done with an ESMA analysis (electron beam micro range analysis) on ZrC{sub g}-coatings. It could be seen, that a reaction layer ...

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The corrosion behavior of steel in water from certain oil fields with various organic inhibitors was studied by applying potentiodynamic technique at pH 5.9. The inhibitors which were used include 2-methylbenzimidazole (I), 2-mercaptobenzimidazole (II), 2-mercapto-5-methylbenzimidazole (III), and 2-mercaptothiazole (IV). The inhibiting efficiency of the different additives was evaluated from their anodic and cathodic polarization curves at different temperatures. A comparative study of curve fitting procedures using the kinetic thermodynamic model and those utilizing well-known adsorption isotherms was undertaken. Three types of isotherms were used, Langmuir, Frumkin and Flory-Huggins isotherm. The results show that the kinetic-thermodynamic model and Flory-Huggins isotherms are more suitable to fit the data for the four inhibitors, at all applied temperatures. From the values of binding constants, K, the order of inhibitor efficiency is: III > IV > II > I and thus ...

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Early recognition of recurrence and work-up of clinically indeterminate lesions may be impaired after reconstruction with silicone implants due to superimposition of the implant or to scarring. This study was undertaken to evaluate the use of contrast-enhanced MRI in patients with silicone implant after breast cancer. Contrast-enhanded MRI was offered to 169 patients. Comparative two- to three-view mammography was also performed in 169 patients, as well as comparative sonography in 144 patients. Conventional imaging and clinical examination detected only 8/13 recurrences, whereas 12/13 were detected by MRI. One recurrence had been visible as a strongly enhancing 2-mm dot in a previous examination (2 years before), but was not called. It was therefore counted as false negative. In addition, multicentricity was detected by MRI alone in two of three cases. MRI correctly diagnosed scar tissue in all cases with indeterminate findings. However, due to false-positive calls caused by enhancing ...

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To evaluate the current situation and implementation of embolization of uterine leiomyomas into the treatment concept in women with symptomatic uterine leiomyomas in Germany. A questionnaire addressing the clinical background of uterine myomas, recommended treatment concepts, preclinical evaluation, technical approach and complications was sent to 164 departments of gynecology and radiology in Germany. 33 radiological departments and 19 gynecological departments submitted a completed questionnaire. Only 7 departments of radiology reported to have own experience with embolization of uterine leiomyomas, while only 2 departments of gynecology considered embolization as an alternative treatment option in patients with symptomatic leiomyomas. 18/33 radiological departments offer this treatment option but get no patient referrals. Agreement was found concerning the indications for treatment, preclinical evaluation by ultrasound and MRI, preferable location of treatable fibroids, technical ...

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Functional imaging of the pharynx used to be the domain of cineradiography, CT and ultrafast CT. The development of modern MRI techniques led to new access to functional disorders of the pharynx. The aim of this study was to implement a new MRI technique to examine oropharyngeal obstructive mechanisms in patients with obstructive sleep apnea (OSA). Sixteen patients suffering from OSA and 6 healthy volunteers were examined on a 1.5 T whole-body imager (`Vision`, Siemens, Erlangen Medical Engineering, Germany) using a circular polarized head coil. Imaging was performed with 2D flash sequences in midsagittal and axial planes. Patients and volunteers were asked to breathe normally through the nose and to simulate snoring and the Mueller maneuver during magnetic resonance imaging (MRI). Prior to MRI, all patients underwent an ear, nose and throat (ENT) examination, functional fiberoptic nasopharyngoscopy and polysomnography. A temporal resolution of 6 images/s and an in-plane resolution of ...

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CT and MRI of acquired abnormalities of the inner ear and cerebello-pontine angle present themselves with very typical findings. The imaging should be adapted to the pathology looked for and either CT or MRI should be used alone or in combination.CT, especially high resolution CT (HRCT), provides an excellent bone contrast, while MRI has a much superior soft tissue contrast. Acute inflammatory changes of the inner ear are solely depicted by contrast-enhanced MRI. HRCT excellently depicts osseous changes of the inner ear and cerebellopontine angle such as chronic ossifying labyrinthitis occurring after acute labyrinthitis, otosclerotic or traumatic changes. Tumorous changes not yielding to bony changes are best delineated by MRI. Posttraumatic hemorrhage and chronic fibrotic changes within the labyrinth are depicted by MRI, only. In conclusion HRCT and MRI are excellent methods to delineate acquired abnormalities of the inner ear and cerebello-pontine angle. HRCT best depicts osseous ...

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The staging of patients with multiple myeloma demands sensitive imaging methods for the assessment of the skeletal system. MRI allows for direct visualization of the bone marrow which exhibits five different infiltration patterns in multiple myeloma: 1. normal appearance of the bone marrow, 2. focal involvement, 3. homogeneous diffuse infiltration, 4. combined diffuse and focal infiltration, 5. ''salt and pepper'' pattern with inhomogeneous bone marrow signals due to multiple fat islands. The combination of T1w-SE and STIR sequences is best suited for detecting all infiltration patterns and for the differential diagnoses e. g. hemangiomas. With parallel imaging in MRI, acquisition times can be markedly reduced and whole-body screening of the bone marrow can be achieved within 30 min. MRI is superior to radiography for the detection of focal as well as diffuse infiltration. Multidetector computed tomography and especially 16- and 64-detector row ...

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Purpose: To evaluate a T{sub 2}-weighted URSE sequence for the assessment of pulmonary infiltrations in comparison to CT. Methods: 28 MRT scans of 22 patients with confirmed pneumonia were recorded on a 1.5 Tesla apparatus with an expiratory and diastolic triggered, T{sub 2}-weighted ultrafast-spin-echo sequence in axial slice mode with the following parameters: TR{sub eff}/T{sub E}/Turbofactor 2000-4000/90 ms/21-23; slice thickness/separation 6/0.6 mm; FOV 360 mm; 24 slices. 24 spiral CTs (sice thickness/table advance: 1-2 mm/10 mm) were available for comparison. The separate evaluation of MRTs and CTs was performed by three radiologists in a consensus procedure with regard to pulmonary lesions (e.g., infiltration, round foci, net patterns) and image quality of the MRTs (4-step scale). Results: In 71% of the cases the CTs and MRTs agreed with the diagnosis and representation of the lesions, in 25% MRT was superior. MRT was better for the detection of pulmonary abscesses. In 93% the ...

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Attention Deficit Hyperactivity Disorder (ADHD) is a neurobiological disorder of early childhood onset. Defining symptoms are chronic impairments of attention, impulse control and motor hyperactivity that frequently persist until adulthood. Miscellaneous causes of the disorder have been discussed. Accumulating evidence from imaging- and molecular genetic studies strengthened the theory of ADHS being a predominantly inherited disorder of neurobiological origin. In the last 15 years, non-invasive brain imaging methods were successfully implemented in pediatric research. Functional magnetic resonance imaging studies gave major insight into the neurobiological correlates of executive malfunction, inhibitory deficits and psychomotoric soft signs. These findings are in good accordance with brain morphometric data indicating a significant volumetric decrease of major components of striato-thalamo-cortical feedback loops, primarily influencing prefrontal executive functioning (e.g. basal ...

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Background. In multiple myeloma 5 different infiltration patterns can be differentiated: 1. Normal appearance of bone marrow, 2. focal involvement, 3. homogeneous diffuse infiltration, 4. combined diffuse and focal infiltration, 5. 'salt-and pepper' pattern with inhomogeneous bone marrow with interposition of fat islands. Methods. For the fast and total acquisition of all patterns a combination of a T1-weighted spin echo sequence and a fat suppression technique is superior. The focal involvement is clearly demonstrated as areas of high signal intensity on e.g. STIR images. Diffuse involvement can be quantified objectively by calculation of the percentage of signal intensity increase after contrast material injection. MRI is superior to X-ray in focal and diffuse involvement. With ultrafast sequences a 'screening' of the whole red bone marrow as for myeloma infiltration is possible. Prognosis. In prognosis studies diffuse infiltration is inferior to ...

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In an epidemiological study of the somatic late effects risk following incorporation of a short lived {alpha}-emitter, 1473 ankylosing spondylitis patients treated with repeated intravenous injections of {sup 224}Ra in the years 1948 - 75, have been observed in the GSF. The usual therapeutic plan consisted of a total of 10 - 12 injections of 1.036 MBq (28 {mu}Ci) of {sup 224}Ra each, given at weekly intervals; this would result in an cumulative {alpha}-dose of 0.56 - 0.67 Gy to the marrow-free skeleton of a 70-kg-man (standard man). These patients have been followed together with a control group of ankylosing spondylitis patients not treated with radioactive drugs and/or X-rays. Until May 1993 (mean follow-up time 19.9 yr), 595 patients of the exposure group and 722 patients of the control group have died, causes of death have been ascertained for 578, resp. 668 patients. Among others we observed in the exposure group 10 cases of leukaemia (vs. 2.7 - 2.8 cases expected, p < 0.001) ...

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The thermochemical calculations performed with a large number of elements to describe the chemical system in a Phebus FP test allow the following conclusions: The metallic absorber materials play a significant role in fission product speciation. At around 1000 C and above, silver iodide is the dominant iodine carrier in a full steam atmosphere in both FPT0 and FPT1. At lower temperatures, cadmium iodide takes over. In a reduced environment, indium iodide becomes important. Caesium iodide does certainly appear; at certain test conditions it becomes the major iodine transporting vehicle. But its role is not greater than that of the other iodides. It has more chances in FPT1 than in FPT0. Chlorine, which was present in FPT0 as a contaminant in relatively large amounts, does not prevent the iodine from forming Csl. Both share the caesium like partners. The evolution of caesium chloride and iodide proceeds in parallel. When CsCl is abundant, Csl is strong, too. Should boron be added to the ...

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We report for the first time about a micromachined mass flow sensor directly integrated between the double guidance and the needle seat into the body of a Common Rail (CR) injection nozzle. The thermal measurement principle was chosen because gaseous as well as liquid mass flows can be determined fast and precisely. Additionally, with glass-ceramic materials fabricated in a low cost batch process, a high temperature and especially pressure stable substrate can be used. The flow sensitive thin film is realized by an e-beam evaporated 110 nm thick molybdenum (Mo) layer. The latter is electrically characterized by the resistivity of {rho} = 8.2 x 10{sup -7} {omega} m ({+-}2%) at room temperature as well as by the first {alpha}=4.5 x 10{sup -4} K{sup -1} ({+-}5%) and second {beta}=3.0 x 10{sup -6} K{sup -2} ({+-}12%) temperature coefficients of resistance up to 300 C. The static temperature field at and around the thin film sensor on the glass-ceramic substrate is investigated with an IR ...

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Aim: Today, MRI is an integral part of the presurgical evaluation of patients suffering from partial epilepsy. These patients frequently show focal morphological abnormalities with potential epileptogenic character and surgical resection of these lesions is associated with superior postsurgical outcome as to seizure frequency. Apart from easily detectable defects, such as post-traumatic lesions or cerebral infarction, as wide variety of mainly small abnormalities can be detected using MRI. Methods: In this study, 484 patients suffering from partial epilepsy of temporal or frontal onset were evaluated for the incidence of different lesions in this population. Results: All lesions found were included without evaluating their potential epileptogenicity, which remains to be proven using other procedures (EEG, SPECT, PET, etc.). Involvement of the hippocampal formation was a major finding in temporal lobe epilepsy, which could be detected as sclerosis (T2w-images), atrophy (T2w-TSE or ...