bluuebunny/crossref_metadata_2025_split huggingface dataset:
Schwerpunkt '83: Mikrowellen in der Medizin
Authors: Knöchel R. , Lüdeke K. M. , Meyer W. 
Published: February 2013

AbstractNach der Beschreibung der dielektrischen Eigenschaften von gesundem Körpergewebe und von Tumorgewebe wird die Möglichkeit der Lokalerwärmung im Körper mit fokussierenden Antennengruppen diskutiert, ein automatisches temperaturgeregeltes Hyperthermiesystem zur Krebstherapie vorgestellt und sein Einsatz im Tierversuch beschrieben. Zur drahtlosen lokalen Temperaturmessung im Körper wurde ein Verfahren auf der Basis implantierter FMR‐Sensoren (FMR = ferrimagnetische Resonanz) entwickelt. Schließlich werden die grundlegenden Eigenschaften der Mikrowellen‐Thermographie erläutert und die Ergebnisse klinischer Anwendungsstudien berichtet.
Die Entdeckung des Quants der schwachen Kraft
Authors: Reithler Hans 
Published: February 2013

AbstractDie Entdeckung schwacher neutraler Ströme vor zehn Jahren war eine glanzvolle Bestätigung der elektroschwachen Theorie. Die Vereinheitlichung der Kopplungskonstanten und die direkte Beobachtung des Quants der schwachen Kraft blieben aber ungeprüft. Dieser Nachweis ist in diesem Jahr zwei Experimentalphysiker‐Gruppen am Proton‐Antiproton‐Speicherring des CERN gelungen.
Mustererkennung
Authors: Lang M. 
Published: February 2013

AbstractWir sind gewohnt, Informationen aus Bildern und Szenen, aus geschriebenen Texten und Zeichnungen, aus gesprochenen Sätzen, aus Musik und aus Geräuschen wahrzunehmen, diese zu interpretieren, zu verarbeiten, im Gedächtnis zu speichern und weiterzuvermitteln. Signale von Sinneseindrücken, die von den Rezeptoren über Nervenbahnen zum Gehirn gelangen, liefern dort nicht nur neue Informationen ab, sondern aktivieren auch bereits im Gedächtnis abgespeichertes und offenbar nach einem flexiblen Organisationsprinzip geordnetes a‐priori‐Wissen. Die Leistungsfähigkeit des universellen menschlichen Mustererkennungssystems kann der Computertechnik als Vorbild für zukünftige Entwicklungen dienen!
Die ersten Briefe Albert Einsteins an Arnold Sommerfeld: Erstveröffentlichung von bisher unbeachteten Briefen
Authors: Eckert M. , Pricha W. 
Published: February 2013

AbstractVor kurzem wurde in einem bislang unbeachteten Teilnachlaß Sommerfelds aus dem Institut für theoretische Physik der Universität München eine bedeutende und umfangreiche Korrespondenz gefunden — darunter auch vier Briefe Einsteins aus den Jahren 1908‐1910. Zusammen mit einem Brief vom 29. September 1909 aus der Dibner Library der Smithsonian Institution stellt dies die früheste, bis heute bekannte Korrespondenz von Einstein mit Sommerfeld dar [1]. Diese Briefe fehlen in dem in Buchform veröffentlichten Briefwechsel der beiden Gelehrten. (A. Hermann (Hrsg.): Albert Einstein/Arnold Sommerfeld. Briefwechsel. Sechzig Briefe aus dem goldenen Zeitalter der modernen Physik. Basel, Stuttgart: Schwabe u. Co. 1968) Die darin enthaltene und ausführlich kommentierte Korrespondenz umfaßt den Zeitraum 1912‐1954. Aus physikhistorischer Sicht ist der Wert der fünf Briefe kaum zu überschätzen, da sie Einblick in die frühe Diskussion über Relativität und Quanten gewährt. Leider befinden sich Sommerfelds Gegenbriefe weder im Einstein‐ noch im Sommerfeld‐Nachlaß.
Optimization of processing parameters for the synthesis of low‐density polyethylene/organically modified montmorillonite nanocomposites using X‐ray diffraction with experimental design
Authors: Campos‐Requena Víctor H , Rivas Bernabé L , Pérez Mónica A , Contreras David , Muñoz Eduardo 
Published: February 2013

AbstractThe influence of the processing parameters on the synthesis of low‐density polyethylene (LDPE)/organically modified montmorillonite (OMM) nanocomposite films was studied using experimental design. Intercalation in the nanocomposites was analysed using X‐ray diffraction and verified using atomic force microscopy. Four direct melt processing parameters were studied to obtain surface maps of intercalation in the nanocomposites: concentration of OMM (clay‐%), concentration of Polybond® 3149 (compatibilizer‐%), mixing temperature (Tmix) and mixing time. An ANOVA validated the polynomial function, and intercalation maps from response surface methodology (RSM) were obtained. The clay‐% parameter had the most significant effect, and Tmix showed no significant effect on intercalation (p < 0.05). A strong synergic interaction between clay‐% and compatibilizer‐% was observed, which is not possible to detect using univariate experiments. RSM provides a powerful tool for choosing the best processing conditions that lead to formulations with the highest intercalations by considering the main factors and their interactions. © 2013 Society of Chemical Industry
Change in I–V characteristics of thin‐film photovoltaic (PV) modules induced by light soaking and thermal annealing effects
Authors: Ishii Tetsuyuki , Otani Kenji , Takashima Takumi , Ikeda Kazuaki 
Published: February 2013

ABSTRACTThe performance of photovoltaic (PV) modules is generally rated under standard test conditions (STC). However, the performance of thin‐film photovoltaic modules is not unique even under STC, because of the “metastability”. The effects of the light soaking and thermal annealing shall be incorporated into an appropriate energy rating standard. In this study, the change in I–V characteristics of thin‐film PV modules caused by the metastability was examined by repeated indoor measurements in addition to round‐robin outdoor measurements. The investigated thin‐film modules were copper indium gallium (di)selenide (CIGS), a‐Si : H, and a‐Si : H/µc‐Si : H (tandem) modules. The increase in the performance of the CIGS module between the initial and final indoor measurements was approximately 8%. Because of light‐induced degradation, the indoor performance of the a‐Si : H and a‐Si : H/µc‐Si : H modules decreased by approximately 35% and 20%, respectively. The performance was improved by about 4–6% under high temperature conditions after the initial degradation. The results suggest that the performance of thin‐film silicon modules can seasonally vary by approximately 4–6% only due to thermal annealing and light soaking effects. The effect of solar spectrum enhanced the outdoor performance of the a‐Si : H module by about 10% under low air mass conditions, although that of the a‐Si : H/µc‐Si : H modules showed a little increase. The currents of these a‐Si : H/µc‐Si : H modules may be limited by the bottom cells. Therefore, it is required to optimize the effect of solar spectrum in addition to the effects of light soaking and thermal annealing, in order to achieve the best performance for thin‐film silicon tandem modules. Copyright © 2013 John Wiley & Sons, Ltd.
Electroactive methacrylate‐based triblock copolymer elastomer for actuator application
Authors: Cho Kie Yong , Hwang Seung Sang , Yoon Ho Gyu , Baek Kyung‐Youl 
Published: February 2013

AbstractA series of ABA triblock copolymers of methyl methacrylate (MMA) and dodecyl methacrylate (DMA) [poly(MMA‐b‐DMA‐b‐MMA)] (PMDM) were synthesized by Ru‐based sequential living radical polymerization. For this, DMA was first polymerized from a difunctional initiator, ethane‐1,2‐diyl bis(2‐chloro‐2‐phenylacetate) with combination of RuCl2(PPh3)3 catalyst and nBu3N additive in toluene at 80 °C. As the conversion of DMA reached over about 90%, MMA was directly added into the reaction solution to give PMDM with controlled molecular weight (Mw/Mn ≤ 1.2). These triblock copolymers showed well‐organized morphologies such as body centered cubic, hexagonal cylinder, and lamella structures both in bulk and in thin film by self‐assembly phenomenon with different poly(methyl methacrylate) (PMMA) weight fractions. Obtained PMDMs with 20–40 wt % of the PMMA segments showed excellent electroactive actuation behaviors at relatively low voltages, which was much superior compared to conventional styrene‐ethylene‐butylene‐styrene triblock copolymer systems due to its higher polarity derived from the methacrylate backbone and lower modulus. © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013
Chain transfer agents in cationic photopolymerization of a bis‐cycloaliphatic epoxide monomer: Kinetic and physical property effects
Authors: Dillman Brian , Jessop Julie L. P. 
Published: February 2013

AbstractThe effects of chain transfer agents (CTA) on cationic ring‐opening polymerization of 3,4‐epoxycyclohexylmethyl‐3′,4′‐epoxycyclohexane carboxylate (EEC) were explored. EEC was polymerized in the presence of various CTAs, and epoxide conversions monitored via Raman spectroscopy. Polymer films were prepared and analyzed by dynamic mechanical analysis. Many of the organic alcohols studied greatly enhanced epoxide polymerization rates and conversion levels. The gel fraction of polymer specimens decreased rapidly with increasing amounts of octanol (gel fraction >90% up to 0.3 equiv OH) but remained high with increasing amounts of 1,2‐propanediol (gel fraction >90% up to 0.6 equiv OH). Increasing the size of primary alcohols had little effect on the polymerization rates and conversions. The polymerization rate decreased with increasing alcohol substitution (1°>2°>3°). Acidic alcohols had very low impact on conversion and polymerization rates relative to the neat epoxy resin. The glass transition temperature was inversely related to the size and amount of CTA. © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013
Block copolystyrene derivatives having flexible alkylsulfonated side chains and hydrophobic alkoxy chains as a proton exchange membrane for fuel cell application
Authors: Sheng Li , Higashihara Tomoya , Maeda Rina , Hayakawa Teruaki , Ueda Mitsuru 
Published: February 2013

AbstractA series of block copolystyrene derivatives, poly{[4‐(4‐sulfobutyloxy)styrene]x‐block‐[4‐(n‐butoxystyrene)]y} (PSBOSx‐b‐PnBOSy), containing a flexible alkylsufonated side chain and hydrophobic alkoxy chain with various ion exchange capacities (IECs) have been synthesized based on living anionic polymerization. The resulting crosslinked membranes were prepared using 4,4′‐methylene‐bis[2,6‐bis(hydroxyethyl)phenol] as the crosslinker in the presence of methanesulfonic acid. The crosslinked PSBOS2.2‐b‐PnBOS1 membrane with IEC of 2.89 mequiv g−1 displays a high proton conductivity (0.01 S cm−1) at 30% relative humidity and 80 °C, which is comparable to that of Nafion. The well‐developed phase separation and the continuous hydrophilic domains in the crosslinked PSBOS2.2‐b‐PnBOS1 membranes have been observed in a transmission electron microscope image. Moreover, the dynamic mechanical analysis measurement and Fenton's reagent testing show that the crosslinked PSBOSx‐b‐PnBOSy membranes have good mechanical properties and oxidative stability. These results indicate that the introduction of flexible alkylsulfonated side chains to the polystyrene main chains positively affect both the proton conductivity and oxidative stability. © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013
Diels‐alder click reaction for the preparation of polycarbonate block copolymers
Authors: Omurtag Pinar Sinem , Gunay Ufuk Saim , Dag Aydan , Durmaz Hakan , Hizal Gurkan , Tunca Umit 
Published: February 2013

AbstractThe Diels‐Alder reaction as a click reaction strategy is applied to the preparation of well‐defined polycarbonate (PC)‐block copolymers. A well‐defined α‐anthracene‐terminated polycarbonate (PC‐anthracene) is prepared using 9‐anthracene methanol as an initiator in the ring opening polymerization of benzyl 5‐methyl‐2‐oxo‐1,3‐dioxane‐5‐carboxylate in CH2Cl2 at room temperature for 5 h. Next, a well‐defined α‐furan protected maleimide‐terminated‐poly(ethylene glycol) (PEG11‐MI or PEG37‐MI), ‐poly(methyl methacrylate) (PMMA26‐MI), and ‐poly(ε‐caprolactone) (PCL27‐MI) were clicked with the PC‐anthracene at reflux temperature of toluene to yield their corresponding PC‐based block copolymers (PC‐b‐PEG, PC‐b‐PMMA, and PC‐b‐PCL). The homopolymer precursors and their block copolymers were characterized by using the GPC, NMR and UV analysis. © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013
Discharge Dynamics and Modes of an Atmospheric Pressure Non‐Equilibrium Air Plasma Jet
Authors: Xian YuBin , Wu ShuQun , Wang Zhan , Huang QuanJun , Lu XinPei , Kolb Juergen F. 
Published: February 2013

AbstractA plasma jet operated with atmospheric pressure air is presented. Unlike the dynamics of plasma jets working with noble gases, the propagation of the jet that is operated with air is primarily determined by the gas flow. This jet can be generated by applying a continuous, i.e., DC high voltage. However, depending on the applied voltage and gas flow rate a true DC operation can be distinguished from a self‐pulsing mode. The gas temperature of the plasma plume when operated in the pulsed mode is lower than for the DC mode. Conversely, emission intensities of atomic oxygen, O, and nitrogen species, N2 and ${\rm N}_{2}^{ + } $, are much higher for the pulsed mode than observed for DC operation. magnified image
Tailoring Surface Properties of Polymeric Separators for Lithium‐Ion Batteries by Cyclonic Atmospheric‐Pressure Plasma
Authors: Huang Chun , Lin Chi‐Cheng , Tsai Ching‐Yuan , Juang Ruey‐Shin 
Published: February 2013

AbstractThis paper reported surface modification and characterization of polymeric separators by cyclonic atmospheric‐pressure plasma for Li‐ion battery use. Water contact angles of the plasma‐modified polymeric separator decreased with increasing treatment time and plasma power. Variations in surface morphology and chemical structure of the plasma‐modified polymeric separators were confirmed by FESEM and XPS. XPS analysis revealed that the surfaces of plasma‐modified polymeric separators had significantly higher concentrations of oxygen functional groups. Moreover, the cyclonic atmospheric‐pressure plasma‐modified polymeric separators showed excellent performance in electrochemical measurements. magnified image
Interaction of cisplatin with a CCHC zinc finger motif
Authors: Castiglione Morelli Maria Antonietta , Ostuni Angela , Cristinziano Pier Luigi , Tesauro Diego , Bavoso Alfonso 
Published: February 2013

The interaction between cisplatin and an 18‐residue CCHC zinc finger motif derived from a retroviral nucleocapsid protein (PyrZf18) has been studied using UV–visible, CD and 1H NMR spectroscopies and ESI‐MS spectrometry.Cisplatin irreversibly blocks the cysteine zinc binding groups in the free peptide and is able to slowly eject zinc from the zinc–peptide complex. The observed end product of the reaction with cisplatin is a complex in which only one ammonia molecule is coordinated to platinum. After an initial binding with two cysteine residues and the formation of the (PyrZf18)–platinum–(NH3)2 complex, a release of one ammonia molecule occurs because of trans‐labilization, and the third cysteine is coordinated, leading to a mixture of isomers and/or conformers of the (PyrZf18)–platinum–NH3 complex. The results are discussed with respect to the potential antiretroviral activity of platinum(II) compounds and to the possible interaction of cisplatin with the cellular nucleic acid binding proteins. Copyright © 2013 European Peptide Society and John Wiley & Sons, Ltd.
Study of silicon thin film solar cells with different back‐reflectors
Authors: Zhu H. , Huang Y. , Mai Y. , Wang Y. , Yin J. , Feng Y. , He T. , Gao J. , Wang Z. , Lan L. , Ni J. , Guan F. , Bai Y. , Ma Y. , Wan M. 
Published: February 2013

AbstractIn this study, hydrogenated amorphous silicon (a‐Si:H) single junction and amorphous/microcrystalline silicon tandem (a‐Si:H/µc‐Si:H) solar cells with different back‐reflectors (BRs) are systematically investigated. A novel white polyvinyl butyral (PVB) foil was used as BR. In addition, the specular aluminum (Al) films and rough Al films were deposited on back float glasses as BRs as well, which were integrated onto the front glass covered with solar cells by laminating with a transparent PVB encapsulation foil. It is found that both types of solar cells (a‐Si:H and a‐Si:H/µc‐Si:H) with white PVB foil BRs show a higher short circuit current density (Jsc) compared to the cells with a specular Al BR. It is mainly due to a high light scattering of white PVB foils. Moreover, the cell with a rough Al film BR shows a low Jsc close to that of cell without any BRs. The great light losses inside the solar cell may be mainly caused by the plasmonic absorption on the rough Al film surface. An a‐Si:H solar cell of 8.3% and an a‐Si:H/µc‐Si:H tandem solar cell of 10.1% were obtained, in which the white PVB foils were used as BRs.
Quantum critical transition from Kondo insulator to metallic state studied by band‐structure calculations for doped compounds: CeRhSb and CeNiSn
Authors: Goraus Jerzy , Ślebarski Andrzej 
Published: February 2013

AbstractWe present the ab initio calculations of the on‐site hybridization between Ce 4f and Ce 5d electrons as well as the Mulliken Ce 5d occupation for the doped Kondo insulators CeRhSb and CeNiSn. In our investigations we have examined the following series: CeRhSb1 − xSnx, CeRh1 − xPdxSb, CeRhSb1 − xTex, Ce1 − xLaxRhSb and CeNi1 − xCuxSn, CeNiSn1 − xSbxSb, Ce1 − xLaxNiSn. The transition from the Kondo insulator to the metallic state induced by doping at some critical concentration xc was recently reported for various dopants based on the resistivity, susceptibility and spectroscopic data. Our calculations show that both the Mulliken occupation of Ce 5d states and the onsite hybridization between Ce 4f and Ce 5d states exhibit critical behavior at nearly the same dopant concentrations as observed in experiment. We also note that for the CeRhSb‐based alloys the disorder is not necessary to explain their critical behavior, in contrast to the CeNiSn‐based series.
High pressure electrical resistivity and specific heat of the heavy fermion compound CeCoGe2.2Si0.8
Authors: Larrea J. J. , Teyssier J. , Rϕnnow H. M. , Lorenzer K.‐A. , Paschen S. 
Published: February 2013

AbstractWe study the evolution of the magnetic ground state close to the putative quantum critical point in CeCoGe2.2Si0.8 by using electrical resistivity and specific heat measurements under the same high hydrostatic pressure conditions. The electrical resistivity shows that the antiferromagnetic ordering temperature, TN, is suppressed above PC = 5.9 kbar, with the emergence of non‐Fermi liquid behavior. On the other hand, the specific heat shows two different magnetic transitions at 0 kbar, one at TN and another one at Tl ≈ 0.3 K. Both transition temperatures are reduced by pressure but remain finite up to at least 7.2 kbar. The height of the specific heat anomaly at TN, ΔCN, is strongly reduced above PC. These features suggest that the quantum criticality in CeCoGe2.2Si0.8 is governed by disorder.
Electronic nematicity and its relation to quantum criticality in Sr3Ru2O7 studied by thermal expansion
Authors: Stingl C. , Perry R. S. , Maeno Y. , Gegenwart P. 
Published: February 2013

AbstractWe report high‐resolution measurements of the in‐plane thermal expansion anisotropy in the vicinity of the electronic nematic phase in Sr3Ru2O7 down to very low temperatures and in varying magnetic field orientation. For fields applied along the c‐direction, a clear second‐order phase transition is found at the nematic phase, with critical behavior compatible with the two‐dimensional Ising universality class (although this is not fully conclusive). Measurements in a slightly tilted magnetic field reveal a broken fourfold in‐plane rotational symmetry, not only within the nematic phase, but extending towards slightly larger fields. We also analyze the universal scaling behavior expected for a metamagnetic quantum critical point, which is realized outside the nematic region. The contours of the magnetostriction suggest a relation between quantum criticality and the nematic phase.
High transconductance ion‐implanted GaN MISFETs using atomic layer deposited high‐k dielectrics
Authors: Gu S. , Katayose H. , Nomoto K. , Nakamura T. , Ohoka A. , Lee K. , Lu W. , Asbeck P. M. 
Published: February 2013

AbstractWe demonstrate MISFETs based on GaN p‐epilayers with ion‐implanted source/drain regions and atomic layer deposited (ALD) gate dielectrics of Al2O3 and HfO2. The fabrication technology is similar to that used for silicon MOSFETs. We find that there are significant shifts (of order 1 V) in threshold voltage between FETs produced with Al2O3 and HfO2 films, enabling depletion mode and enhancement mode device operation for the same substrate doping. The GaN MISFETs obtained maximum drain current of 580mA/mm and an extrinsic transconductance as high as 160 mS/mm. To the authors' knowledge, the transconductance achieved represents record performance for ion‐implanted MISFETs of GaN without heterostructure barriers. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
SHIP‐LOCK–INDUCED SURGES IN AN IMPOUNDED RIVER AND THEIR IMPACT ON SUBDAILY FLOW VELOCITY VARIATION
Authors: Maeck A. , Lorke A. 
Published: February 2013

ABSTRACTThe majority of large rivers are fragmented by dams, and navigation is often supported by the installation of ship locks. Despite their ubiquitous existence, the effect of ship locks on river basin hydrodynamics is rarely considered in an environmental context.Ship‐lock operation induces single‐wave crests or troughs called surges, which propagate along the basin and are subject to reflection at the up‐ and downstream impoundments. We used pressure sensors and acoustic Doppler current profiler measurements to investigate the effects of up‐ and downstream ship locking on the water level and the current velocity dynamics in a 12.9‐km‐long basin of the impounded river Saar (Germany).Ship lifting at the lower dam and the associated water export from the basin results in a negative surge propagating upstream, whereas a descending ship‐lock operation at the upper dam of the basin creates a positive surge propagating downstream. Both types of waves are subject to positive reflection at the opposing dams. Frequent lock operations lead to a complex pattern of multiple superimposing surges. The resulting water level fluctuations are comparable in magnitude with those associated with discharge variations due to hydropower peaking but occur at much shorter timescales. Associated with the water surface displacement during wave passage is a corresponding increase or decrease of the longitudinal current velocity. The magnitude of wave‐induced velocity fluctuations can exceed mean flow velocities by a factor of three and, depending on wave type and direction, can result in a reversal of the main flow direction of the river. Because of their longevity of several hours and superposition effects, ship‐lock–induced surges govern 66.3% and 45.4% of the subdaily variations in flow velocity and water level, respectively. This article concludes with a discussion of the potential effects of lock‐induced flow dynamics in impoundments on oxygen dynamics and methane ebullition. Copyright © 2013 John Wiley & Sons, Ltd.