Library

X
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
    Recent developments in sensorless and quasi-sensorless drive (2002)
    Bradford : Emerald
    Compel 21 (2002), S. 307-322 
    Details
    ISSN: 0332-1649
    Source: Emerald Fulltext Archive Database 1994-2005
    Topics: Electrical Engineering, Measurement and Control Technology , Mathematics
    Notes: There are two main types of speed/position sensorless closed-loop variable-speed electrical drives: sensorless and quasi-sensorless drives. In sensorless drives, the classical speed and position sensors (transducers) are absent and are replaced by mathematical-model-based and/or artificial-intelligence-based estimators. In quasi-sensorless drives, instead of conventional speed/position sensors, smart sensor bearings are used (e.g. SKF smart sensor bearings). The present paper discusses the latest developments in the field of sensorless and quasi-sensorless variable-speed high-performance drives. Thus, a new family of sensorless and quasi-sensorless induction motor and permanent magnet synchronous motor drives are also discussed (e.g. new sensorless vector and DTC drives, etc.). Methods which enable the operation of these drives at very low speed and also at zero stator frequency are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1108/03321640210416395
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Field-weakening in high-performance PMSM drives (2002)
    Bradford : Emerald
    Compel 21 (2002), S. 338-354 
    Details
    ISSN: 0332-1649
    Source: Emerald Fulltext Archive Database 1994-2005
    Topics: Electrical Engineering, Measurement and Control Technology , Mathematics
    Notes: The comparative analysis of field-weakening (FW) in vector controlled and DTC permanent magnet synchronous motor drives is performed. The results of simulations and a comprehensive set of experiments are also given. The possibility of unstable operation in the high-speed region using DTC is emphasised. The present paper also highlights some important differences between DTC and vector drives in FW, such as quickness of torque response, torque/flux/current ripple content and implementation aspects. For this purpose two types of DTC drives are implemented, a classical DTC and also a DTC scheme with torque ripple reduction.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1108/03321640210416412
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Sensorless induction motor and permanent magnet synchronous motor drives using natural field orientation (2002)
    Bradford : Emerald
    Compel 21 (2002), S. 323-337 
    Details
    ISSN: 0332-1649
    Source: Emerald Fulltext Archive Database 1994-2005
    Topics: Electrical Engineering, Measurement and Control Technology , Mathematics
    Notes: The present paper will discuss newly developed fully digital sensorless induction motor and permanent magnet motor synchronous motor drives, which employ natural field orientation (NFO). So far only vector-type of NFO induction motor drives have been discussed in the literature, and very limited experimental results have been shown. In addition, the paper will also discuss new sensorless DTC-type of NFO induction motor drives (NFO-DTC drives). Using fully digital implementations of the new NFO-type induction motor and permanent magnet drives, experimental results will be shown for various operating conditions, including slow and fast reversals at very low speed. Robustness to parameter deviations will also be demonstrated. The developed new types of NFO drives can also work at zero stator frequency and sustained zero frequency operation will also be demonstrated. The drives have been tested in basically two environments: where the load is a dc motor; and where a crane drive is implemented. In contrast to other sensorless crane drives, which develop stability problems, it was found that the new NFO drives can operate in a stable manner under all operating conditions including zero frequency. This allows for many new applications.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1108/03321640210416403
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    A full-band Monte Carlo model for hole transport in silicon (1997)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 81 (1997), S. 2250-2255 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Hole transport in bulk silicon is explored using an efficient and accurate Monte Carlo (MC) tool based on the local pseudopotential band structure. Acoustic and optical phonon scattering, ionized impurity scattering, and impact ionization are the dominant scattering mechanisms that have been included. In the interest of computational efficiency, momentum relaxation times have been used to describe ionized impurity scattering and self-scattering rates have been computed in a dynamic fashion. The temperature and doping dependence of low-field hole mobility is obtained and good agreement with experimental data has been observed. MC extracted impact ionization coefficients are also shown to agree well with published experimental data. Momentum and energy relaxation times are obtained as a function of the average hole energy for use in moment based hydrodynamic simulators. The MC model is suitable for studying both low-field and high-field hole transport in silicon. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.364287
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Distribution and chemical fractionation of some heavy metals in bottom sediments of Lake Nasser (1997)
    Springer
    Hydrobiologia 364 (1997), S. 31-40 
    Details
    ISSN: 1573-5117
    Keywords: heavy metals ; sediments ; fractionation ; AAS ; Egypt
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Distribution and phase association of Cd, Cr, Cu, Fe, Mn, Ni,Pb, Zn and organic matter in Nile sediments taken from LakeNasser (Aswan, Egypt) were investigated. The sediment sampleswere subjected to selective chemical extraction proceduresdesigned to fractionate the particulate heavy metals into sixfractions: (A) ammonium acetate-extractable metals; (B) sodiumacetate-extractable metals; (C) acid oxalate-extractablemetals; (D) hydroxylamine HCl-extractable metals; (E) aquaregia-extractable metals and (F) total metals (HF/HCl/HNO3destruction). Exchangeable metals which can be extracted byammonium acetate solution are generally considered readilybioavailable as they are weakly bound and may equilibrateeasily with the aqueous phases. In the present study very smallconcentrations of all heavy metals considered were found inthis phase. Between this phase and the metal phases which arenot bioavailable (those exist in highly resistant phases) thereexist several geochemical phases (fractions B, C & D) that maypotentially release their associated metals under changingenvironmental conditions, such as pH and redox potential in thewater sediment interface.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1003112008122
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    3-Hydroxy-3-methylglutaryl-CoA lyase deficiency in a boy with VATER association (1998)
    Springer
    Journal of inherited metabolic disease 21 (1998), S. 443-444 
    Details
    ISSN: 1573-2665
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1005387532004
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Carnitine-acylcarnitine translocase deficiency is a treatable disease (1999)
    Springer
    Journal of inherited metabolic disease 22 (1999), S. 271-275 
    Details
    ISSN: 1573-2665
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1005546408659
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Isovaleric acidemia appearing as diabetic ketoacidosis (1996)
    Springer
    Journal of inherited metabolic disease 19 (1996), S. 85-86 
    Details
    ISSN: 1573-2665
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01799353
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Electrospray tandem mass spectrometry in the diagnosis of organic acidemiasPaper presented in part at the British Mass Spectrometry Society Meeting, Canterbury, 1993. (1994)
    New York, NY : Wiley-Blackwell
    Rapid Communications in Mass Spectrometry 8 (1994), S. 129-133 
    Details
    ISSN: 0951-4198
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: A novel procedure based on electrospray tandem mass spectrometry (ESI-MS/MS) has been used in the diagnosis of organic acidemias. The method is based on the determination of acylcarnitine profiles from blood spots collected on Guthrie cards. The acylcarnitines are extracted with methanol, derivatized to their butyl esters and analyzed by ESI-MS/MS. Precursor-ion scanning of the common fragment at m/z 85 of the butyl esters yields highly diagnostic acylcarnitine profiles. Analysis time is one minute per sample and is fully automated. Examples are given of normal profiles, of profiles from two patients with fatty acid oxidation defects, and of a case of propionic acidemia. The technique is simple, rapid and specific, and shows potential for routine application in neonatal screening of organic acidemias.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/rcm.1290080124
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Organic lead compounds in vehicle exhaust (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Applied Organometallic Chemistry 2 (1988), S. 95-100 
    Details
    ISSN: 0268-2605
    Keywords: Organolead emissions ; vehicle exhaust ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Species-specific measurements of the five tetraalkyllead compounds used in gasoline and their intermediate decomposition products, the tri- and di-alkyllead species, have been made in vehicle exhaust fumes. Under normal engine running conditions 0.3-3% of the lead emitted in exhaust is as an organic compound, but cold, choked engines emit proportionally much larger amounts of alkyllead. Alkyllead is emitted in both the gas and the aerosol phases.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aoc.590020202
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...