366 research outputs found

    Temperature-controlled change of charge transport mechanisms in nonionic water-in-oil microemulsions

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     The temperature-controlled transition from the Stokes charge transport of aqueous nanodroplets to the intrinsic conduction of nanodroplet clusters in nonionic microemulsions was studied. Two different charge transport processes apparent from a minimum value of the conductance have been simulated based on straightforward physical models. Their predictions compare favourably with the observation

    A conductometric analysis of mesogel formation by ABA block copolymers in w/o microemulsions

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    A straightforward thermodynamic model is suggested to describe the (conductometrically measured) variation of the percolation temperature (ΔTc)(\Delta T_{\rm c}) of a w/o microemulsion (H2_{2}O/AOT/isooctane) as a function of the initial concentration ratio (R=P0/D0)(R=P_{0}/D_{0}) of ABA triblock copolymers (b-POE-b-PI-b-POE) and nanodroplets. Two copolymer concentration ranges are predicted, i.e. ΔTcR1/5\Delta T_{\rm c}\sim R^{1/5} for R10R\leq 10 and ΔTcR\Delta T_{\rm c}\sim R for R10R\geq 10 which are compatible with our experiments

    Charge Transport as Suitable Tool to Study Near-Percolation Phenomena

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    Electrical conductivity measurements in non-ionic (CmE5, m=10, 12) percolated w/o microemulsions with added carrier electrolytes (NaCl and/or AOT) serve as empirical tools to trace near percolation limit phenomena. Salient effects are observed if AOT (structurally a strong electrolyte) is dissolved in the w/o interface of the nanodroplets. They are due to the fact that AOT becomes a typical weak electrolyte since it is by its very nature confined to the pentaethylene glycol/water mixture in the interface. The results indicate further a continuous phase transition from spheres to cylinders a conclusion already earlier arrived at (see H.F. Eicke, W. Meier, H. Hammerich, Colloids Surfaces A 118 (1996) 141)

    A logistic regression analysis comparing minimalistic approach and intubation anaesthesia in patients undergoing transfemoral transcatheter aortic valve replacement.

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    AIMS:Patients with postoperative delirium (POD) after transcatheter aortic valve replacement (TAVR) are ventilated and hospitalized longer and suffer increased in-hospital mortality. This study hypothesized that a minimalistic approach with conscious sedation during transfemoral aortic valve replacement (TF-AVR) protects against delirium, time of mechanical ventilation, and increased length of stay in intensive care unit (ICU) compared to intubation anaesthesia. METHODS AND RESULTS:308 patients which underwent TF-AVR in our centre between 01/2013 and 08/2017 were retrospectively evaluated regarding postoperative delirium, time of mechanical ventilation, and days in ICU. TF-AVR was performed with intubation anaesthesia in 245 patients and with conscious sedation in 63. The operative risk estimated by the logEUROScore was similar in both groups (intubation: 13.28 +/-9.06%, conscious sedation: 12.24 +/-6.77%, p = 0.395). In the conscious sedation group procedure duration was shorter (0.61 +/-0.91h vs. 1.75 +/-0.96h, p<0.001). The risk for intraprocedural complications was not influenced by the anaesthesia method (OR conscious sedation instead of intubation 1.66, p = 0.117), but days on ICU (-2.21 days, p<0.0001) and minutes of mechanical ventilation (-531.2 min, p < 0.0001) were reduced. Furthermore, the risk of POD was decreased when TF-AVR was performed under conscious sedation (6.35% vs. 18.18%, OR 0.29, p = 0.021). CONCLUSIONS:Time of mechanical ventilation, risk of POD, and days on ICU were substantially reduced in patients who underwent TF-AVR under conscious sedation. Our data suggest that TF-AVR with conscious sedation is safe with a beneficial postoperative course in clinical practice, and should be considered the favoured approach

    First measurement of the Zμ+μZ\rightarrow \mu^+ \mu^- angular coefficients in the forward region of pppp collisions at s=13\sqrt{s}=13 TeV

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    The first study of the angular distribution of μ+μ\mu^+ \mu^- pairs produced in the forward rapidity region via the Drell-Yan reaction ppγ/Z+Xl+l+Xpp \rightarrow \gamma^{*}/Z +X \rightarrow l^+ l^- + X is presented, using data collected with the LHCb detector at a centre-of-mass energy of 13TeV, corresponding to an integrated luminosity of 5.1 fb1\rm{fb}^{-1}. The coefficients of the five leading terms in the angular distribution are determined as a function of the dimuon transverse momentum and rapidity. The results are compared to various theoretical predictions of the ZZ-boson production mechanism and can also be used to probe transverse-momentum-dependent parton distributions within the proton

    Precision measurement of forward ZZ boson production in proton-proton collisions at s=13\sqrt{s} = 13 TeV

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    A precision measurement of the ZZ boson production cross-section at s=13\sqrt{s} = 13 TeV in the forward region is presented, using pppp collision data collected by the LHCb detector, corresponding to an integrated luminosity of 5.1 fb1^{-1}. The production cross-section is measured using Zμ+μZ\rightarrow\mu^+\mu^- events within the fiducial region defined as pseudorapidity 2.0202.020 GeV/cc for both muons and dimuon invariant mass 60<Mμμ<12060<M_{\mu\mu}<120 GeV/c2c^2. The integrated cross-section is determined to be \begin{equation*} \sigma(Z\rightarrow\mu^+\mu^-) = 195.3 \pm 0.2 \pm 1.5 \pm 3.9~pb, \end{equation*} where the first uncertainty is statistical, the second is systematic, and the third is due to the luminosity determination. The measured results are in agreement with theoretical predictions, including a prediction at next-to-next-to-leading order in perturbative quantum chromodynamics and a prediction with resummation

    First measurement of the Zμ+μZ\rightarrow \mu^+ \mu^- angular coefficients in the forward region of pppp collisions at s=13\sqrt{s}=13 TeV

    No full text
    The first study of the angular distribution of μ+μ\mu^+ \mu^- pairs produced in the forward rapidity region via the Drell-Yan reaction ppγ/Z+Xl+l+Xpp \rightarrow \gamma^{*}/Z +X \rightarrow l^+ l^- + X is presented, using data collected with the LHCb detector at a centre-of-mass energy of 13TeV, corresponding to an integrated luminosity of 5.1 fb1\rm{fb}^{-1}. The coefficients of the five leading terms in the angular distribution are determined as a function of the dimuon transverse momentum and rapidity. The results are compared to various theoretical predictions of the ZZ-boson production mechanism and can also be used to probe transverse-momentum-dependent parton distributions within the proton
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