Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 75 (1994), S. 7745-7751 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Novel compounds RE6Fe13X (X=Cu, Ag, Au, Zn, Cd, Hg) have been synthesized by arc melting (Cu, Ag, Au) or by reaction sintering (Zn, Cd, Hg), followed by heat treatment at 550 or 600 °C up to 350 h in evacuated silica capsules. From room temperature x-ray powder diffraction analyses the alloys were found to crystallize with the ordered Nd6Fe13Si type. The Curie point of all the compounds is found to lie around room temperature. Due to their low magnetization values a ferrimagnetic coupling within the Fe sublattice is suggested. A canted RE-spin structure cannot be ruled out. 57Fe Mössbauer spectra were recorded from the samples with X=Ag and Au. Additionally, 197Au spectra were taken from the two Au-containing compounds. The 57Fe spectra are composed of various subpatterns, originating from the different Fe sites and were found to be essentially unaffected by the specific element RE and X. In all cases under investigation the spectra could only be fitted under the assumption of an easy axis of magnetization lying within the basal plane. The 197Au spectra reveal that the Au atoms predominantely occupy the 4a site.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    [S.l.] : International Union of Crystallography (IUCr)
    Acta crystallographica 49 (1993), S. 198-202 
    ISSN: 1600-5724
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Notes: Mössbauer diffraction experiments were performed on a single crystal of lithium heptagermanate in the temperature range 250–350 K. The high energy resolution of resonant γ radiation was used to separate elastically and inelastically scattered components. A lattice expansion along c and a decrease of the intensity of the elastically scattered radiation (IBragg) connected with an increase of the intensity of the inelastically scattered radiation (ITDS) are observed at the transition from the para- to the ferroelectric phase at 283.5 K. The experimentally determined maximum of ITDS/lBragg appearing at the phase transition is much more pronounced in comparison with that predicted from TDS-correction programs, which are based on the lattice dynamical theory restricted to acoustic phonons only.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Bioprocess and biosystems engineering 7 (1991), S. 177-182 
    ISSN: 1432-0797
    Source: Springer Online Journal Archives 1860-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract The macroscopic mathematical model based on compartments with ideal mixing zones and tanks-in series was evaluated. Based on the experimental data obtained in a 300 dm3 pilot reactor and the dependence of mixing time on the volume of liquid phase, we have found mathematical relations between the ratio of vessel diameter to liquid level, adjustable parameters of model and the mixing time.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Bioprocess and biosystems engineering 7 (1991), S. 171-176 
    ISSN: 1432-0797
    Source: Springer Online Journal Archives 1860-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract A mathematical model for single and multi step deep-jet bioreactors is presented. A stagewise approach based on macroscopic mechanistic model which divides the reactor into compartments with good quality of mixing and plug flow regions (macromixer), was used. For the mathematical representation of this model a system of differential equations, describing the concentration of tracer in structural elements based on mass balance, and the Runge-Kutta-Fehlberg numerical method of integration, was applied. The mixing time in a 300 dm3 tank was determined by conductivity method with NaCl as tracer.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Thermomyces lanuginosus, isolated from self-heated jute stacks in Bangladesh, was able to produce a very high level of cellulase-free xylanase in shake cultures using inexpensive lignocellulosic biomass. Of the nine lignocellulosic substrates tested, corn cobs were found to be the best inducer of xylanase activity. The laboratory results of xylanase production have been successfully scaled up to VABIO (Voest-Alpine Biomass Technology Center) scale using a 15-m3 fermentor for industrial production and application of xylanase. In addition, some properties of the enzyme in crude culture filtrate produced on corn cobs are presented. The enzyme exhibited very satisfactory storage stability at 4–30°C either as crude culture filtrate or as spray- or freeze-dried powder. The crude enzyme was active over a broad range of pH and had activity optima at pH 6.5 and 70–75°C. The enzyme was almost thermostable (91–92%) at pH 6.5 and 9.0 after 41 h preincubation at 55°C and lost only 20–33% activity after 188 h. In contrast, it was much less thermostable at pH 5.0 and 11.0. Xylanases produced on different lignocellulosic substrates exhibited differences in thermostability at 55°C and pH 6.5.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Der Onkologe 2 (1996), S. 346-351 
    ISSN: 1433-0415
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Der Onkologe 2 (1996), S. 376-378 
    ISSN: 1433-0415
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 1433-0458
    Keywords: Schlüsselwörter Tracheobronchoskopie ; Ösophagoskopie ; HNO ; Komplikationen ; Key words Tracheobronchoscopy ; Esophagoscopy ; Surgical complications
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary It is the task of each medical specialty to develop guidelines for diagnosis and therapies. Examinations done by several specialties should follow a common consensus. A randomized survey at 70 German ENT departments investigated the current position of tracheobronchoscopy and esophagoscopy at each institution. Sixty questionnaires were evaluable. Altogether 8,295 tracheobronchoscopies and 10,404 esophagoscopies were performed. Thirty-six percent of all tracheobronchoscopies and 6% of all esophagoscopies were done with a flexible system. Approximately 58% of all tracheobronchoscopies and 55% of all esophagoscopies were performed for tumor staging. Complications during tracheobronchoscopy occurred in 0.8% of cases and in 0.58% of the esophagoscopies. Using these data an interdisciplinary quality assurance concept was developed for tracheobronchoscopy and esophagoscopy. Current experience has shown that a otolaryngologists in Germany mainly perform rigid tracheobronchoscopy and esophagoscopy. Although endoscopy is mostly done in cases with varied anatomic structures, complications are very rare and comparable to flexible techniques. Greater experience with flexible systems also is to be encouraged in ENT departments.
    Notes: Zusammenfassung Hintergrund: Es muß Aufgabe jedes einzelnen Fachbereichs sein, Leitlinien für die von ihm behandelten Erkrankungen und durchgeführten Untersuchungen zu erstellen. Für fachübergreifende Behandlungen ergibt sich die Forderung nach einem gemeinsamen Konsens. Material und Methoden: Durch eine anonymisierte Umfrage an 70 HNO-Kliniken und Belegabteilungen sollte ein Ist-Stand der Tracheobronchoskopie und Ösophagoskopie in der Hals-Nasen-Ohren-Heilkunde erhoben werden. Ausgewertet werden konnten insgesamt 60 Fragebögen. Unter Berücksichtigung dieser Ergebnisse wurde ein Leitlinienentwurf „Tracheobronchoskopie und Ösophagoskopie” erarbeitet. Ergebnisse: Insgesamt wurden 8295 Tracheobronchoskopien und 10404 Ösophagoskopien durchgeführt; 36% der Tracheobronchoskopien und 6% der Ösophagoskopien erfolgten mit einem flexiblen System. In 58% der Fälle erfolgte die Tracheobronchoskopie zum Tumorstaging, bei der Ösophagoskopie betrug die Anzahl der Untersuchungen zum Tumorstaging 55%. Die Komplikationsrate bei der Tracheobronchoskopie betrug 0,8%, bei der Ösophagoskopie 0,58%. Aufbauend auf diesen Strukturdaten wurde ein interdisziplinär erarbeiteter Leitlinienentwurf in einem Delphiverfahren abgeglichen. Schlußfolgerungen: Die Hals-Nasen-Ohren-Ärzte in Deutschland führen mehrheitlich die starre Tracheobronchoskopie und Ösophagoskopie durch. Obwohl größtenteils bei veränderten anatomischen Strukturen endoskopiert wird, geschieht dies mit Komplikationsraten, die vergleichbar sind mit internationalen Studien bei Einsatz flexibler Systeme. Trotzdem sollte sich der HNO-Arzt vermehrt auch um die flexiblen Techniken bemühen.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Applied microbiology and biotechnology 34 (1991), S. 579-581 
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary A large number of submerged citric acid fermentations in a beet molasses substrate was studied. The development of Aspergillus niger from conidia to pellets was followed. Rheological characteristics of the fermentation broth including the pellets were determined. The results obtained confirm the fact that the non-Newtonian pseudoplastic behaviour of the fermentation broth was due to the presence of mycelial pellets. The most significant changes in rheological properties occurred during the period of maximal citric acid production and increase in biomass.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Applied microbiology and biotechnology 36 (1992), S. 701-707 
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary The production of cellulase and xylanase was investigated with a newly isolated strain of Trichoderma viride BT 2169. The medium composition was optimized on a shake-flask scale using the Graeco-Latin square technique. The temperature and time for optimal growth and production of the enzymes in shake cultures were optimized using a central composite design. The temperature optima for maximal production of filter paper cellulase (FPase), xylanase and β-gluosidase were 32.8°, 34.7° and 31.1° C, respectively, and the optimum times for production of these enzymes were found to be 144, 158 and 170 h, respectively. The optimized culture medium and conditions (33° C) gave 0.55 unit of FPase, 188.1 units of xylanase and 3.37 units of β-glucosidase per milliliter of culture filtrate at 144 h of shake culture. Among different carbon sources tested, the maximum enzyme activities were produced with sulphite pulp and all three enzymes were produced irrespective of the carbon sources used. Batch fermentation in a laboratory fermentor using 2% sulphite pulp allowed the production of 0.61 unit of FPase, 145.0 units of xylanase and 2.72 units of β-glucosidase. In a fed-batch fermentation on 6% final Avicel concentration FPase and β-glucosidase were 3.0 and 2.4 times higher respectively than those in batch fermentation on 2% Avicel. The pH and temperature optima as well as pH and temperature stabilities of T. viride enzymes were found to be comparable to T. reesei and some other fungal enzymes.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...