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
Filter
  • 1995-1999  (7)
  • 1975-1979  (1)
  • 1
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 105 (1996), S. 2436-2440 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: An atom–atom Lennard-Jones (LJ) model for the intermolecular potential of carborane molecules (B10C2H12) is developed and used in a series of classical constant-pressure molecular dynamics simulations of p-, m- and o-carborane crystals, at several temperatures and zero pressure. The potential model reproduces many structural and dynamical properties of these crystals, in particular the high temperature orientationally disordered plastic phase common to the three compounds. This work stresses the need of further experimental data to improve the potential model. © 1996 American Institute of Physics.
    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. : American Chemical Society
    Journal of the American Chemical Society 117 (1995), S. 4328-4332 
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Fatigue & fracture of engineering materials & structures 19 (1996), S. 0 
    ISSN: 1460-2695
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract— Fatigue crack growth rates in corner notched specimens of forged Ti-6A1-4V, used in the manufacture of rotating aero-engine components, have been measured for fatigue loadings that combine major and minor stress cycles. The loadings are simple representations of the flight cycle and the potential in-flight vibrations, each loading block consisting of high-frequency minor cycles superimposed on the major cycle dwell at maximum load. The crack growth rates are dependent on the number and stress ratio of the minor cycles, but only when they individually contribute to the growth of the crack. Estimates of the fatigue threshold values and near-threshold growth rates associated with the minor cycles have been made, all potential load history effects having been ascribed to the minor cycle component of the loading. Using this data, satisfactory crack propagation life predictions have been demonstrated for a wide range of test conditions involving the conjoint action of major and minor stress cycles.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Science Ltd
    Fatigue & fracture of engineering materials & structures 22 (1999), S. 0 
    ISSN: 1460-2695
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Essential to the assessment of the fatigue integrity of critical components is the prediction of their crack propagation lives. This requires the effective and efficient characterization of the fatigue crack growth behaviour of the material when using a small number of specimens. A test facility, able to control the range of applied load (ΔP ) and range of stress intensity factor (ΔK ), has been used to determine the fatigue crack growth rates in corner notched specimens of Udimet 720 for stress ratios of 0.5, 0.1 and −1.0. Initially, the results were analysed in terms of the three-point secant data reduction method. Subsequently, the benefits to be gained by the use of alternative methods involving regression analysis have been examined. The effectiveness of the procedures has been assessed in terms of the extent to which they reduce the width of the scatter band representing the fatigue crack growth behaviour and the accuracy with which the experimental observed fatigue lives are predicted. On this basis, the results from the ΔK controlled tests were superior to those obtained under ΔP control, when analysed by similar data reduction methods. In addition, the results from ΔK tests were improved when the secant method was replaced by a linear regression method, which allowed the sample interval to be reduced and more levels of constant ΔK to be examined in a single specimen.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Fatigue & fracture of engineering materials & structures 20 (1997), S. 0 
    ISSN: 1460-2695
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract— The scatter in experimentally determined fatigue crack growth rates is dependent, in part, on the data reduction process applied to the paired values of crack length and number of cycles recorded in crack growth tests. An additional data reduction process is proposed which replaces the original test data by a smooth curve. Analysis of mid-range growth rate data for Udimet 720 shows that the introduction of this additional data reduction procedure reduces the scatter in the calculated growth rates, increases the effectiveness of Walker's method in accounting for the effects of stress ratio, and leads to more accurate predictions of the experimental crack propagation lives of test specimens.
    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
    Surgical endoscopy and other interventional techniques 9 (1995), S. 329-331 
    ISSN: 1432-2218
    Keywords: Osmotic purgation ; Nulytely ; Golytely ; Polyethylene glycol
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract An osmotic laxative containing polyethylene glycol and sodium sulfate (Golytely® Braintree Laboratories, Inc., Braintree, MA) is widely used to clean the colon for colonoscopy. However, its salty taste makes the mixture unpalatable. We therefore tested the claim that a similar solution but without sodium sulfate (Golytely-RSS® Braintree Laboratories, Inc., Braintree, MA) makes preparation of the colon more acceptable to patients in a double-blinded randomized controlled trial. Colonic preparation using polyethylene glycol with or without sodium sulfate was randomized in 100 patients due to undergo colonoscopy. The overall acceptability of the regimen was measured on a linear analogue scale and an estimate of symptoms was obtained. Body weight and serum electrolytes, urea, creatinine, hemoglobin and hematocrit were determined before and after preparation in order to assess fluid absorption. The efficacy of colonic cleansing was graded by the colonoscopist. Four patients did not complete the protocol, 47 received the regimen containing sodium sulfate and 49 received the regimen without it. The two groups did not differ in age or body mass. There was no statistical difference in the overall acceptability of the two regimens to the patients (median acceptability rating 74 for regimen with sodium sulfate, range 4–100 compared with 77 for regimen without, range 3–100, p=0.32, Mann-Whitney test). Nor was there any difference in taste, nausea, vomiting, cramping or perianal discomfort or in the endoscopists' rating of the cleanliness of the colon. The serum sodium concentration rose slightly (mean 1.6 mmol/L) when the regimen with sodium sulfate was used. Moreover, prescribing the laxative regimen without sodium sulfate increased the cost of the regimen by 65 percent. In preparing the colon for colonoscopy, omitting sodium sulfate from the conventional mixture of polyethylene glycol and sodium sulfate does not make the preparation more acceptable to patients, does not affect the cleanliness of the colon and increases the cost of the laxative substantially. Golytely® is therefore preferable to Golytely-RSS®.
    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
    Journal of inherited metabolic disease 18 (1995), S. 177-181 
    ISSN: 1573-2665
    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
    Electronic Resource
    Electronic Resource
    Springer
    Journal of materials science 12 (1977), S. 61-74 
    ISSN: 1573-4803
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Si-Al-O-N ceramics have been prepared by hot-pressing mixtures of Si3N4, AIN and SiO2 (with an addition of 1% MgO) having varying ratios of AIN/SiO2. Microstructural analysis by transmission electron microscopy and Auger electron spectroscopy has demonstrated the progressive increase in grain-boundary silicate glass in pressings prepared from compositions with excess SiO2 to compositions given by the formula Si6−zAlzOzN8−z. This formula represents the simple substitution of Al for Si atoms and O for N atoms in the hexagonalβSi3N4 crystal. Microstructures for this “balanced” composition are essentially single phase, consiting of non-faceted, sub-micron,β′ grains with a grain-boundary segregate layer of glass-forming silicate composition, containing impurity and additive metal ions, which may be detected only by Auger spectroscopy. This microstructure is in contrast with “unbalanced” compositions which contain facetedβ′ grains joined by a glassy silicate phase which is easily detected by electron microscopy. Final microstructural analysis combined with observations of density and phase content with progress of hot-pressing has confirmed the important role of liquid silicate formation and a “solution-reprecipitation” mechanism for densification. The presence of a 1% MgO additive is shown to accelerate this process, forming a low melting point silicate by reaction with SiO2, assisting the early solution of AIN and the reprecipitation ofβ′ substituted crystals.
    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...