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
    ISSN: 1420-9136
    Keywords: Geothermics ; heat flow ; Northwest Canada ; basin studies ; heat flow variations
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Temperature data from deep petroleum exploration wells and thermal conductivity estimates based on net rock analysis data have been used to make terrestrial heat flow estimates along two profiles across the sedimentary strata of the Mackenzie Delta, northern Yukon, and offshore Beaufort Sea regions. Both profiles exhibit low heat flow values that range from 34 mWm−2 to 58 mWm−2, and little change occurs over large distances in the continental part of the area. Low heat flow values (〈40 mWm−2) occur in the Beaufort-Mackenzie Basin and Rapid Depression, both of which are areas of thick successions of Cretacecus and Tertiary clastic sedimentary strata. High heat flow values of almost 80 mWm−2 occur to the south in the Taiga Nahoni Foldbelt and values as high as 60 mWm−2 are indicated along the Aklavik Arch Complex, northeast of Aklavik. The regional variations of effective thermal conductivity are insufficient to account for the heat flow variations along the profiles, and so these may indicate deep radiogenic or other heat sources.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Pure and applied geophysics 134 (1990), S. 473-483 
    ISSN: 1420-9136
    Keywords: Geothermal gradients ; heat flow ; Arctic Canada
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Thermal gradients have been calculated and heat flow estimates made for 34 petroleum exploration wells along four regional profiles crossing the Mesozoic-Cenozoic Beaufort-Mackenzie Basin of northern Canada. The geothermal gradients vary from 22 mKm−1 to 44 mKm−1. Four sets of possible thermal conductivity values were used to calculate a range of heat flow values for each well. Generally low heat flow is observed in wells within the deeper portions of the basin and higher heat flow values occur in wells along the Aklavik Arch Complex which forms the southeastern margin of the basin. The contribution to heat flow by heat generation below the Mesozoic-Cenozoic basin fill sediments has been considered. The heat flow contribution from sub-Mesozoic sedimentary strata and underlying basement is highest along the basin-bounding Aklavik Arch Complex. The decrease in heat flow from below the basin fill sediments toward the basin depocenter may be related to basinward crustal thinning and corresponding reductions in intra-crustal radiogenic heat production.
    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
    Journal of molecular medicine 44 (1966), S. 100-101 
    ISSN: 1432-1440
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary A simple and rapid routine method for the estimation of oestriol, 17β-oestradiol and oestrone in human urine by thin layer chromatography is described. When standards of oestriol, 17β-oestradiol and oestrone in different amounts are chromatographed at the same time with the urine extracts, it is possible, to get a semiquantitative determination of the single oestrogens with day light and UV-light. The optimal conditions of hydrolysis and extraction and the purification method are proved by recovery estimations.
    Notes: Zusammenfassung Es wird eine einfache und schnelle dünnschichtchromatographische Methode zur Bestimmung der klassischen Oestrogene Oestriol, Oestradiol und Oestron beschrieben. Durch gleichzeitige Chromatographie der Testsubstanzen Oestriol, Oestradiol und Oestron in verschiedener Menge läßt sich im Tages- und UV-Licht eine semiquantitative Aussage über die einzelnen Oestrogenfraktionen machen. Die günstigsten Hydrolysebedingungen und das von uns angegebene Extraktions-, Reinigungs- und Chromatographieverfahren werden durch Zugabe bekannter Oestrogenmengen überprüft.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1432-1084
    Keywords: Key words: Interventional MRI ; Diagnostic brain biopsy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract. The purpose of our study was to evaluate the feasibility and accuracy of brain biopsies performed within a vertically opened MR system. We worked with the interventional 0.5-T MR “SIGNA SP” (General Electric Medical Systems, Milwaukee, Wis.) with an integrated tracking device “Flashpoint Position Encoder” (Image Guided Technologies, USA). As a holding device for this instrument we constructed a special frame. The whole system allows an exact adjustment of an optimum biopsy direction and guidance of the biopsy in a non-stereotactic, interactive mode in near real-time. As biopsy tools we used MR-compatible aspiration and specially made side-cut needles (Daum, Germany; E-Z-EM, USA). We performed a prospective diagnostic brain biopsy study in 18 patients. Guidance of the needle was carried out using gradient-echo single-slice technique. The sample was taken after controlling the exact position of the needle tip on spin-echo images. In 12 cases an exact neuropathological diagnosis was possible. In 6 cases of negative biopsy (4 aspiration biopsies) the samples were not representative. Our results demonstrate the feasibility of interactive MR-guided minimally invasive brain biopsies in an open MR system. The best results were achieved using cut needles for biopsies of contrast-enhancing lesions visible on T1-weighted gradient-echo guidance sequence.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    facet.materialart.
    Unknown
    Menasha, Wis. : Periodicals Archive Online (PAO)
    The Accounting Review. 60:1 (1985:Jan.) 109 
    ISSN: 0001-4826
    Topics: Economics
    Notes: FINANCIAL REPORTING, Clyde P. Stickney, Editor
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 0942-0940
    Keywords: Keywords: Intra-operative magnetic resonance imaging; neuronavigation; tumour biopsy; brain tumours.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary  Objectives. A number of different image-guided surgical techniques have been developed during the past decade. None of these methods can provide the surgeon with information about the dynamic changes that occur intra-operatively.  Material and Method. The first vertical open 0.5 T MRI-scanner for intra-operative MRI-guided neurosurgery in Germany was installed at the University of Leipzig during the summer 1996. Since autumn 1996 a number of surgical procedures including biopsies (n=31), craniotomies (n=32), transsphenoidal procedures (n=8) and interstitial lasertherapies (n=3) have been performed using intra-operative MR image guidance.  Results. The development of MR-compatible and MR-safe non-magnetic instruments and components had to be solved. Specific surgical instruments were developed to perform biopsies, craniotomies, microsurgical tumour resections and transsphenoidal procedures in the 0.5-T open MRI. Several components required adaptation including the head holder, the stereotactic navigation device, the high speed drill, the suction unit, the ultrasonic aspirator, the bipolar coagulation, the laser probe and the surgical microscope. All these newly developed technical features enable the neurosurgeon to perform a large number of surgical procedures under direct control and guidance of intra-operative MR imaging. In contrast to frame-based for framless navigation systems, intra-operative MRI provides accurate and immediate information during the progress of surgery. These intra-operative images allow definitive localization and targeting of the lesions and accommodate anatomical changes that may occur during surgery.  Conclusion. Intra-operative MRI is helpful for navigation as well as determining of tumour margins to achieve a complete and safe resection of intracranial lesions. Complications related to the surgical procedure are reduced and the risk of neurological deterioration due to tumour removal and postoperative complications is minimized. It can be concluded that the intra-operative application of interventional MRI technology may represent a major step forward in the field of neurosurgery.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 0942-0940
    Keywords: Keywords: Intra-operative magnetic resonance imaging; neuronavigation; brain tumors.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary ¶ Objectives. A number of different image-guided surgical techniques have been developed during the past decade. None of these methods can provide the surgeon with information about the dynamic changes that occur intra-operatively. The development of open configurated MRI-scanners leads to new perspectives in the intra-operative management and resection control of intracranial tumours.  Material and Method. Using a vertical open 0.5 T MRI-scanner for intra-operative MR image guided neurosurgery, forty-four patients (20 female/24 male) with different intracranial tumours have been operated on since August 1997. The patients ranged in age from 20 to 70 years (mean±standard deviation=47.2±15.9 ys).  Results. In 36 (82%) of 44 patients the tumours were completely removed with the aid of MR image-guidance. In 8 cases (18%) complete removal was not achieved. Postoperatively 6 (14%) of 44 patients developed neurological deficits which were transient in 5 cases (paresis, dysphasia). In these patients the tumours were located in or near eloquent brain areas (sensorimotor cortex/speech center).  Conclusion. Intra-operative MRI is helpful for navigation as well as determining of tumour margins to achieve a complete and safe resection of intracranial lesions. Complications related to the surgical procedure are reduced and the risk of neurological deterioration due to tumour removal and postoperative complications is minimized. It can be concluded that the intra-operative application of interventional MRI technology may represent a major step foreward in the field of neurosurgery.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    [s.l.] : Nature Publishing Group
    Nature 192 (1961), S. 889-890 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] We planned to determine whether acceleration could be detected in the prophase of meiosis in anthers of Tradescantia paludosa, in which the prophase stages investigated (from pachytene and diplotene onwards) are of sufficient duration to do so. The anthers were cultured on a modification of the ...
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Nuclear Physics, Section A 246 (1975), S. 187-209 
    ISSN: 0375-9474
    Keywords: Nuclear moments
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Physics
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 63 (1992), S. 2817-2818 
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: A multipassage magnetic spectrometer has been constructed which allows selection of a specific high charge state from the extracted ion pulse of our electron beam ion source (EBIS) and to reinject it in the emptied source, now using the electron beam of meanwhile changed energy as a target of free electrons for the study of ionization, dielectronic recombination (DR), or radiative electron capture (REC). The spectrometer consists of a H-magnet with round pole pieces and 4 identical arrangements of achromatic lenses and mirrors under 90° forming a versatile ion switchyard with the possibility of recirculation. The chromaticity of the recirculating transport system and the dispersion of this spectrometer are adjustable by electric potentials on suitably placed electrostatic deflectors inside of the magnetic field. For the injection of ions from an external ion source into the EBIS and to the beam lines, the mirror potentials are pulsed accordingly.
    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...