TY - JOUR A1 - Mohsen, Ayman A1 - Kind, Rainer A1 - Sobolev, Stephan Vladimir A1 - Weber, Michael T1 - Thickness of the lithosphere east of the Dead Sea Transform JF - Geophysical journal international N2 - We use the S receiver function method to study the lithosphere at the Dead Sea Transform (DST). A temporary network of 22 seismic broad-band stations was operated on both sides of the DST from 2000 to 2001 as part of the DESERT project. We also used data from six additional permanent broad-band seismic stations at the DST and in the surrounding area, that is, in Turkey, Saudi Arabia, Egypt and Cyprus. Clear S-to-P converted phases from the crust-mantle boundary (Moho) and a deeper discontinuity, which we interpret as lithosphere-asthenosphere boundary (LAB) have been observed. The Moho depth (30-38 km) obtained from S receiver functions agrees well with the results from P receiver functions and other geophysical data. We observe thinning of the lithosphere on the eastern side of the DST from 80 km in the north of the Dead Sea to about 65 km at the Gulf of Aqaba. On the western side of the DST, the few data indicate a thin LAB of about 65 km. For comparison, we found a 90-km-thick lithosphere in eastern Turkey and a 160-km-thick lithosphere under the Arabian shield, respectively. These observations support previous suggestions, based on xenolith data, heat flow observations, regional uplift history and geodynamic modelling, that the lithosphere around DST has been significantly thinned in the Late Cenozoic, likely following rifting and spreading of the Red Sea. KW - Dead Sea Transform KW - S receiver functions KW - thickness of the lithosphere Y1 - 2006 U6 - https://doi.org/10.1111/j.1365-246X.2006.03185.x SN - 0956-540X SN - 1365-246X VL - 167 IS - 2 SP - 845 EP - 852 PB - Blackwell CY - Oxford ER - TY - THES A1 - Bellin, Ingo T1 - Thermosensitive Polymer Networks with Two Different Shapes in Memory Y1 - 2006 CY - Potsdam ER - TY - JOUR A1 - Ostermeyer, Martin A1 - Mudge, Damien A1 - Veitch, Peter John A1 - Munch, Jesper T1 - Thermally induced birefringence in Nd : YAG slab lasers N2 - We study thermally induced birefringence in crystalline Nd:YAG zigzag slab lasers and the associated depolarization losses. The optimum crystallographic orientation of the zigzag slab within the Nd:YAG boule and photoelastic effects in crystalline Nd:YAG slabs are briefly discussed. The depolarization is evaluated using the temperature and stress distributions, calculated using a finite element model, for realistically pumped and cooled slabs of finite dimensions. Jones matrices are then used to calculate the depolarization of the zigzag laser mode. We compare the predictions with measurements of depolarization, and suggest useful criteria for the design of the gain media for such lasers. Y1 - 2006 UR - http://www.opticsinfobase.org/ U6 - https://doi.org/10.1364/AO.45.005368 ER - TY - JOUR A1 - Flores Suárez, Rosaura A1 - Mellinger, Axel A1 - Wegener, Michael A1 - Wirges, Werner A1 - Gerhard, Reimund A1 - Singh, Rajeev T1 - Thermal-pulse tomography of polarization distributions in a cylindrical geometry JF - IEEE transactions on dielectrics and electrical insulation N2 - Fast, three-dimensional polarization mapping in piezoelectric sensor cables was performed by means of the novel thermal-pulse tomography (TPT) technique with a lateral resolution of 200 mum. The active piezoelectric cable material (a copolymer of polyvinylidene fluoride with trifluoroethylene) was electrically poled with a point-to-cable corona discharge. A focused laser was employed to heat the opaque outer electrode, and the short-circuit current generated by the thermal pulse was used to obtain 3D polarization maps via the scale transformation method. The article describes the TPT technique as a fast non-destructive option for studying cylindrical geometries. Y1 - 2006 U6 - https://doi.org/10.1109/TDEI.2006.258210 SN - 1070-9878 VL - 13 IS - 5 SP - 1030 EP - 1035 PB - IEEE CY - Piscataway ER - TY - JOUR A1 - Mellinger, Axel A1 - Wegener, Michael A1 - Wirges, Werner A1 - Mallepally, Rajendar Reddy A1 - Gerhard, Reimund T1 - Thermal and temporal stability of ferroelectret films made from cellular polypropylene/air composites N2 - Ferroelectrets are thin films of polymer foams, exhibiting piezoelectric properties after electrical charging. Ferroelectret foams usually consist of a cellular polymer structure filled with air. Polymer-air composites are elastically soft due to their high air content as well as due to the size and shape of the polymer walls. Their elastically soft composite structure is one essential key for the working principle of ferroelectrets, besides the permanent trapping of electric charges inside the polymer voids. The elastic properties allow large deformations of the electrically charged voids. However, the composite structure can also possibly limit the stability and consequently the range of applications because of, e. g., penetration of gas and liquids accompanied by discharge phenomena or because of a mechanical pre-load which may be required during the application. Here, we discuss various stability aspects related to the piezoelectric properties of polypropylene ferroelectrets. Near and below room temperature, the piezoelectric effect and the stability of the trapped charges are practically independent from humidity during long-time storage in a humid atmosphere or water, or from operating conditions, such as continuous mechanical excitation. Thermal treatment of cellular polypropylene above -10 degrees C leads to a softening of the voided structure which is apparent from the decreasing values of the elastic modulus. This decrease results in an increase of the piezoelectric activity. Heating above 60 degrees C, however, leads to a decrease in piezoelectricity Y1 - 2006 ER - TY - JOUR A1 - Mellinger, Axel A1 - Wegener, Michael A1 - Wirges, Werner A1 - Mallepally, Rajendar Reddy A1 - Gerhard, Reimund T1 - Thermal and temporal stability of ferroelectret films made from cellular polypropylene/air composites Y1 - 2006 ER - TY - JOUR A1 - Andrianov, Ivan A1 - Saalfrank, Peter T1 - Theoretical study of vibration-phonon coupling of H adsorbed on a Si(100) surface N2 - In this paper a perturbation-theory study of vibrational lifetimes for the bending and stretching modes of hydrogen adsorbed on a Si(100) surface is presented. The hydrogen-silicon interaction is treated with a semiempirical bond-order potential. Calculations are performed for H-Si clusters of different sizes. The finite lifetime is due to vibration-phonon coupling, which is assumed to be linear or bilinear in the phonon and nonlinear in the H-Si stretching and bending modes. Lifetimes and vibrational transition rates are evaluated with one- and two-phonon processes taken into account. Temperature effects are also discussed. In agreement with the experiment and previous theoretical treatment it is found that the H-Si (upsilon(s)=1) stretching vibration decays on a nanosecond timescale, whereas for the H-Si (upsilon(b)=1) bending mode a picosecond decay is predicted. For higher-excited vibrations, simple scaling laws are found if the excitation energies are not too large. The relaxation mechanisms for the excited H-Si stretching and the H-Si bending modes are analyzed in detail. Y1 - 2006 UR - http://jcp.aip.org/ U6 - https://doi.org/10.1063/1.2161191 SN - 0021-9606 ER - TY - JOUR A1 - Charron, Eric A1 - Cirone, M. A. A1 - Negretti, Antonio A1 - Schmiedmayer, Jörg A1 - Calarco, Tommaso T1 - Theoretical analysis of a realistic atom-chip quantum gate N2 - We present a detailed, realistic analysis of the implementation of a proposal for a quantum phase gate based on atomic vibrational states, specializing it to neutral rubidium atoms on atom chips. We show how to create a double-well potential with static currents on the atom chips, using for all relevant parameters values that are achieved with present technology. The potential barrier between the two wells can be modified by varying the currents in order to realize a quantum phase gate for qubit states encoded in the atomic external degree of freedom. The gate performance is analyzed through numerical simulations; the operation time is similar to 10 ms with a performance fidelity above 99.9%. For storage of the state between the operations the qubit state can be transferred efficiently via Raman transitions to two hyperfine states, where its decoherence is strongly inhibited. In addition we discuss the limits imposed by the proximity of the surface to the gate fidelity. Y1 - 2006 UR - http://pra.aps.org/ SN - 1050-2947 ER - TY - JOUR A1 - Harutyunyan, Gohar A1 - Schulze, Bert-Wolfgang T1 - The Zaremba problem with singular interfaces as a corner boundary value problem JF - Potential analysis : an international journal devoted to the interactions between potential theory, probability theory, geometry and functional analysis N2 - We study mixed boundary value problems for an elliptic operator A on a manifold X with boundary Y, i.e., Au = f in int X, T (+/-) u = g(+/-) on int Y+/-, where Y is subdivided into subsets Y+/- with an interface Z and boundary conditions T+/- on Y+/- that are Shapiro-Lopatinskij elliptic up to Z from the respective sides. We assume that Z subset of Y is a manifold with conical singularity v. As an example we consider the Zaremba problem, where A is the Laplacian and T- Dirichlet, T+ Neumann conditions. The problem is treated as a corner boundary value problem near v which is the new point and the main difficulty in this paper. Outside v the problem belongs to the edge calculus as is shown in Bull. Sci. Math. ( to appear). With a mixed problem we associate Fredholm operators in weighted corner Sobolev spaces with double weights, under suitable edge conditions along Z {v} of trace and potential type. We construct parametrices within the calculus and establish the regularity of solutions. KW - Zaremba problem KW - corner Sobolev spaces with double weights KW - pseudo-differential boundary value problems Y1 - 2006 U6 - https://doi.org/10.1007/s11118-006-9020-6 SN - 0926-2601 VL - 25 SP - 327 EP - 369 PB - Springer CY - Dordrecht ER - TY - JOUR A1 - Hazan, Valerie A1 - Sennema, Anke A1 - Faulkner, Andrew A1 - Ortega-Llebaria, Marta A1 - Iba, Midori A1 - Chung, Hyunsong T1 - The use of visual cues in the perception of non-native consonant contrasts N2 - This study assessed the extent to which second-language learners are sensitive to phonetic information contained in visual cues when identifying a non-native phonemic contrast. In experiment 1, Spanish and Japanese learners of English were tested on their perception of a labial/labiodental consonant contrast in audio (A), visual (V), and audio-visual (AV) modalities. Spanish students showed better performance overall, and much greater sensitivity to visual cues than Japanese students. Both learner groups achieved higher scores in the A V than in the A test condition, thus showing evidence of audio-visual benefit. Experiment 2 examined the perception of the less visually-salient /1/-/r/ contrast in Japanese and Korean learners of English. Korean learners obtained much higher scores in auditory and audio- visual conditions than in the visual condition, while Japanese learners generally performed poorly in both modalities. Neither. group showed evidence of audio-visual benefit. These results show the impact of the language background of the learner and visual salience of the contrast on the use of visual cues for a non-native contrast. Significant correlations between scores in the auditory and visual conditions suggest that increasing auditory proficiency in identifying a non-native contrast is linked with an increasing proficiency in using visual cues to the contrast. Y1 - 2006 UR - http://scitation.aip.org/jasa/ U6 - https://doi.org/10.1121/1.2166611 SN - 0001-4966 ER -