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
    On the thermodynamic limit of photovoltaic energy conversion (1981)
    Springer
    Applied physics 25 (1981), S. 119-125 
    Details
    ISSN: 1432-0630
    Keywords: 72.40 ; 85.30 ; 85.60
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract An infinite stack ofp—n junctions with smoothly varying bandgap from ∞ to 0 is considered. AnI —V characteristic is derived, which is more correct than the classical exponential characteristic. It is shown that open-circuit operation is a reversible process and leads to the Carnot efficiency, if one defines the efficiency in the way that is usual in the theory of thermodynamic engines. If instead one uses the definition of efficiency usual in photovoltaics, open-circuit mode gives rise to zero efficiency. Then operation at maximum efficiency equals operation at maximum power and is not reversible.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00901283
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Hypertension associated with skeletal traction in children (1992)
    Springer
    European journal of pediatrics 151 (1992), S. 543-545 
    Details
    ISSN: 1432-1076
    Keywords: Arterial hypertension ; Skeletal traction ; Fractures ; Children ; Hypercalcaemia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Since traction-associated hypertension seems to be a relatively unknown phenomenon, a survey was done of its incidence in children treated with skeletal traction for fractures and orthopaedic diseases. The correlation with hypercalcaemia, a possible aetiological factor, was also explored. Blood pressure was recorded three times a day with an automatic oscillometric unit during the stay in the hospital. Serum calcium, creatinine and total protein concentrations were measured once a week. Patients with pre-existing diseases or renal trauma were excluded. Arterial hypertension (systolic and/or diastolic) was found in 31/50 children (62%). In almost half of these the rise in systolic blood pressure was 10 mmHg or more above the 95th percentile. Hypertension occurred in most cases within the first 3 weeks of treatment; in 7 children it developed after 3 or more weeks of traction. All children became normotensive within 1 week after discontinuation of traction. Clinical symptoms were rare: two children complained of headache. In no instance had traction to be discontinued before the planned date because of hypertension. In the hypertensive group were more preschool children and more humeral fractures as compared to the normotensive group (n=19). Hypercalcaemia occurred in 11 children and was equally distributed in hypertensive and in normotensive children. It is concluded that arterial hypertension is a frequent finding in children in traction, but its clinical relevance is uncertain. Hypercalcaemia is not a rare finding in immobilized children, but probably plays no causative role in traction-related hypertension.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01957765
    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...