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  • 1
    Digitale Medien
    Digitale Medien
    Multiphonon hopping conduction in nonconventional chromium-doped Bi3Pb1Sr3Ca3Cu4−nCrnOx (n=0.025–0.2) glasses with nanocrystalline particles and clusters (2000)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 88 (2000), S. 5033-5042 
    Details
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Transport properties of Cr containing multicomponent oxide glasses Bi3Pb1Sr3Ca3Cu4−nCrnOx (n=0.025, 0.05, 0.1, and 0.2) dispersed with nanocrystalline particles (5–20 nm depending on the values of n) have been reported in the temperature range of 250–450 K. Conductivity of this glass-nanocrystal composite system shows little decrease with increasing Cr content. Above θD/2 (θD is the Debye temperature), conductivity data can be analyzed with small polaron hopping models. Interestingly, unlike undoped Bi4Sr3Ca3Cu4Ox (or Bi-4334) glasses [showing nonadiabatic small polaron hopping (SPH) conduction at T〉θD/2], the Cr doped glasses supports adiabatic SPH conduction mechanism above θD/2 indicating change of glass network structure due to partial substitution of Cu by Cr. But below this temperature Mott's or Greaves' variable range hopping models can be consistently used to fit the experimental conductivity data only with larger (compared to the usual transition metal oxide glasses) values of the density of states at the Fermi level N(EF). The most probable transport mechanism for the entire range of temperature and glass compositions is concluded to be due to multiphonon tunneling of large polarons between the nanoclusters present in the glasses which is also in sharp contrast to the behavior of the undoped (Bi-4334) glass. All the glass samples (except n≥0.2) are found to become superconductors by annealing at higher temperatures. © 2000 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.1317237
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  • 2
    Digitale Medien
    Digitale Medien
    Particle size and magnetic field dependent resistivity and thermoelectric power of La0.5Pb0.5MnO3 above and below metal–insulator transition (2002)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 91 (2002), S. 5125-5134 
    Details
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: The effect of particle size on the transport properties (resistivity and thermopower) of La0.5Pb0.5MnO3 has been investigated both in the presence and in the absence of magnetic field B=0.0–1.5 T (maximum). Grain size, dc conductivity; and the metal–insulator transition temperature Tp of the sample increase with increasing annealing time. Grain size has, however, comparatively little effect on the Seebeck coefficient S. Magnetoresistance is higher for the samples with smaller grain sizes. dc magnetic susceptibility also increases with increasing grain size. High temperature (T〉θD/2) resistivity data well fit the small polaron hopping model. Polaron hopping energy WH decreases but polaron radius rp increases with the increase of grain size. In the metallic regime (for T〈Tp), resistivity data fit well with ρ=ρ0+ρ2.5 T2.5 and the transport mechanism is attributed mainly to the magnon-carrier scattering (∼T2.5). In all the samples with different grain sizes, S changes sign below Tp. In contrast to magnetoresistance, application of magnetic field increases S at low temperature (T〈Tp) for these samples. Thermopower data in the metallic phase (both for B=0.0 and 1.5 T) can be analyzed by considering a spin-wave fluctuation term (∼T4) in addition to the magnon-scattering term similar to the case of resistivity data. Although the variable range hopping mechanism is supported from the resistivity data (for Tp〉T〉θD/2), it is hard to justify this model from the temperature dependent thermopower data. © 2002 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.1459618
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  • 3
    Digitale Medien
    Digitale Medien
    Women's perceptions of decision-making about hysterectomy (2004)
    Oxford, UK and Malden, USA : Blackwell Publishing Ltd
    BJOG 111 (2004), S. 0 
    Details
    ISSN: 1471-0528
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Objective  To explore women's views of decision-making relating to hysterectomy.Design  Structured questionnaire and in-depth interview surveys.Setting  A teaching hospital and a district general hospital in northeast Scotland.Sample  Women scheduled for hysterectomy for benign menstrual problems.Methods  Pre-operative questionnaires were sent to a consecutive sample of women booked for hysterectomy. A purposive sample was interviewed post-operatively.Main outcome measures  Women's experiences of, and satisfaction with, information provision, communication and decision-making processes; the relationship between views of decision-making processes and decisions made.Results  One hundred and four women (66%) returned questionnaires. Most responded positively to structured questions about the process by which the decision to have a hysterectomy was reached. Almost all (97%) reported satisfaction with the decision made. Twenty women were interviewed post-operatively. A number, including some who had responded positively on the questionnaire, described aspects of the decision-making process that were suboptimal. Women's perceptions of the decision-making process, including the way their doctors communicated with them, did impinge on their views of the course of action selected. Some women had residual doubts about the appropriateness of hysterectomy.Conclusions  In a significant minority of women, there are important shortcomings in current patterns of information provision and communication relating to decision-making. These are unlikely to be picked up by conventional structured patient feedback surveys. Further efforts are required to ensure that women are adequately informed and involved in decisions about gynaecological treatments.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1046/j.1471-0528.2003.00027.x
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  • 4
    Digitale Medien
    Digitale Medien
    Grain structure effects on the lattice thermal conductivity of Ti-based half-Heusler alloys (2002)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 81 (2002), S. 43-45 
    Details
    ISSN: 1077-3118
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Half-Heusler alloys with the general formula TiNiSn1−xSbx are currently being investigated for their potential as thermoelectric (TE) materials. A systematic investigation of the effect of Sb doping on the Sn site and Zr doping on the Ti site on the electrical and thermal transport of the TiNiSn system has been performed. Unexpectedly, lattice thermal conductivity κL appears to increase somewhat randomly with small amounts (x〈5%) of Sb doping. Subsequently, an investigation of grain structure in these Sb-doped materials has been found to correlate with the anomalous behavior of κL. Furthermore, effects of submicron grain sizes on κL in ball milled and shock compressed samples are also presented. © 2002 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.1488698
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  • 5
    Digitale Medien
    Digitale Medien
    High figure of merit in Eu-filled CoSb3-based skutterudites (2002)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 80 (2002), S. 598-600 
    Details
    ISSN: 1077-3118
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: We report measurements of electrical resistivity, thermopower, thermal conductivity, and Hall coefficient of polycrystalline Eu-doped CoSb3-based skutterudites with compositions Eu0.20Co4Sb12, Eu0.43Co4Sb11.59Ge0.31, and Eu0.42Co4Sb11.37Ge0.50. The relatively high mobility of these compounds, as compared to that of La- and Ce-filled skutterudites, may play a role in the large thermoelectric figure of merit (ZT〉1 at 700 K) of Eu0.42Co4Sb11.37Ge0.50. We discuss the significant potential of these compounds for thermoelectric applications. © 2002 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.1433911
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  • 6
    Digitale Medien
    Digitale Medien
    Effect of Sb doping on the thermoelectric properties of Ti-based half-Heusler compounds, TiNiSn1−xSbx (2000)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 77 (2000), S. 2476-2478 
    Details
    ISSN: 1077-3118
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Half-Heusler alloys (MgAgAs type) with the general formula MNiSn where M is a group IV transition metal (Hf, Zr, or Ti) are currently under investigation for potential thermoelectric materials. These materials exhibit a high negative thermopower (−40 to −250 μV/K) and low electrical resistivity values (0.1–8 mΩ cm) both of which are necessary for a potential thermoelectric material. Results are presented in this letter regarding the effect of Sb doping on the Sn site (TiNiSn1−xSbx). The Sb doping leads to a relatively large power factor of (0.2–1.0) W/m K at room temperature for small concentrations of Sb. These values are comparable to that of Bi2Te3 alloys, which are the current state-of-the-art thermoelectric materials. The power factor is much larger at T(approximate)650 K where it is over 4 W/m K making these materials very attractive for potential power generation considerations. © 2000 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.1318237
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  • 7
    Digitale Medien
    Digitale Medien
    Depoling a ferroelectric capacitor (2002)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 80 (2002), S. 3373-3375 
    Details
    ISSN: 1077-3118
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: A "shrinking hysteresis loop" method, analogous to degaussing a ferromagnet, is used to depolarize a ferroelectric thin film and reach the origin, nominally the zero polarization-zero applied field state. Scanning piezoresponse imaging of the depoled state shows fragmentation into domains of up and down polarization that constitute the zero polarization state. Furthermore, the depoling method improves the left–right symmetry of the coercive field in "imprinted" samples. © 2002 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.1476063
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  • 8
    Digitale Medien
    Digitale Medien
    CLINICAL STUDY OF POROKERATOSIS: REPORTS OF 10 CASES (1976)
    Oxford, UK : Blackwell Publishing Ltd
    International journal of dermatology 15 (1976), S. 0 
    Details
    ISSN: 1365-4632
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: : Morphological and histopathological observations made over 4 years of 10 patients with porokeratosis are described. Absence of familial involvement was notable. Association of porokeratosis with tinea cruris, leprosy and epithelioma was seen, and their possible correlation is discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1111/j.1365-4362.1976.tb05096.x
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  • 9
    Digitale Medien
    Digitale Medien
    A randomised controlled trial of intravenous versus inhalational analgesia during outpatient oocyte recovery (2000)
    Oxford, UK : Blackwell Science Ltd
    Anaesthesia 55 (2000), S. 0 
    Details
    ISSN: 1365-2044
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: To compare the efficacy and acceptability of conventional intravenous sedation with patient-controlled inhalational isodesox, 57 women undergoing outpatient oocyte recovery were randomly allocated to receive isodesox by face mask, while 55 women were given intravenous fentanyl and midazolam. Women's satisfaction with pain relief, peroperative pain, clouding of memory and the surgeons' assessment of operating conditions were evaluated. Thirty-eight women in the inhalation group (67%) and 41 (75%) women in the intravenous group were ‘very satisfied’ with their analgesia (p = 0.41). The mean (SD) pain score in women given isodesox was 46.8 (34.7), while in the intravenous group it was 34.1 (21.3) (p = 0.02). Oxygen saturation levels 〈 94% were recorded in one woman using isodesox and in 16 (29%) women given intravenous analgesia. Despite higher pain scores, in comparison with the conventional analgesia, patient-controlled isodesox offers a safer method of pain relief with comparable satisfaction rates.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1046/j.1365-2044.2000.01468.x
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  • 10
    Digitale Medien
    Digitale Medien
    Constituents of Pachygone ovata and Pharmacological Action of its Major Leaf Alkaloid (1979)
    s.l. : American Chemical Society
    Journal of natural products 42 (1979), S. 399-406 
    Details
    ISSN: 1520-6025
    Quelle: ACS Legacy Archives
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1021/np50004a007
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