690 research outputs found
Inverse relaxation in polypropylene
No full textWOS: 000308649500005Observations are reported on isotactic polypropylene in uniaxial tensile relaxation tests on specimens subjected to tension up to various maximum strains and retraction down to various stresses. Noticeable evolution of shapes of relaxation curves under retraction is revealed with stress at the beginning of relaxation process: with a decrease in this stress, relaxation diagrams characterized by a monotonic decay of stress with time (simple relaxation) become, first, non-monotonic (mixed relaxation), and, finally, monotonically increasing (inverse relaxation). A thorough investigation is performed on the effect of multi-cycle preloading (maximum strain per cycle, minimum stress per cycle, number of cycles, and strain rate) on transition from simple to mixed and to inverse relaxation. It is found that (1) intensity of mixed relaxation increases with maximum strain when this parameter remains below the yield strain and decreases in the post-yield region of deformations, (2) an increase in number of cycles under preloading leads to reduction of intensity of mixed relaxation and transition from mixed to inverse relaxation, (3) inverse relaxation diagrams of specimens subjected to the same preloading program with various strain rates can be superposed to construct a master-curve. A constitutive model is developed in cyclic viscoelastoplasticity of semicrystalline polymers. A polymer is thought of as two-phase continuum composed of amorphous and crystalline regions. Both phases were treated as viscoelastoplastic media whose response was governed by different kinetic equations for evolution of plastic strains and different kinematic equations for changes in relaxation rates and relaxation spectra driven by plastic flow. Good agreement is demonstrated between the experimental data in relaxation tests under retraction and the results of numerical simulation.Danish Agency for Science, Technology and Innovation [RK 2010-2012 B4]; Scientific and Technological Research Council of Turkey (TUBITAK)The first author acknowledges financial support by the Danish Agency for Science, Technology and Innovation (project RK 2010-2012 B4). The second author acknowledges the fellowship that was supported by The Scientific and Technological Research Council of Turkey (TUBITAK)
Semiconductors V. 39, I. 01
No full textSemiconductors -- January 2005
Volume 39, Issue 1, pp. 1-159
ATOMIC STRUCTURE AND NONELECTRONIC PROPERTIES OF SEMICONDUCTORS
Effect of the Parameters of Sapphire Substrates on the Crystalline Quality of GaN Layers
Yu. N. Drozdov, N. V. Vostokov, D. M. Gaponova, V. M. Danil'tsev, M. N. Drozdov, O. I. Khrykin, A. S. Filimonov, and V. I. Shashkin
pp. 1-3 Full Text: PDF (108 kB)
ELECTRONIC AND OPTICAL PROPERTIES OF SEMICONDUCTORS
Properties of the GaSb:Mn Layers Deposited from Laser Plasma
Yu. A. Danilov, E. S. Demidov, Yu. N. Drozdov, V. P. Lesnikov, and V. V. Podol'skii
pp. 4-7 Full Text: PDF (59 kB)
Effect of the Conditions of Metal–Organic Chemical-Vapor Epitaxy on the Properties of GaInAsN Epitaxial Films
V. M. Danil'tsev, D. M. Gaponova, M. N. Drozdov, Yu. N. Drozdov, A. V. Murel', D. A. Pryakhin, O. I. Khrykin, and V. I. Shashkin
pp. 8-10 Full Text: PDF (50 kB)
SEMICONDUCTOR STRUCTURES, INTERFACES, AND SURFACES
Growth of BGaAs Layers on GaAs Substrates by Metal–Organic Vapor-Phase Epitaxy
D. A. Pryakhin, V. M. Danil'tsev, Yu. N. Drozdov, M. N. Drozdov, D. M. Gaponova, A. V. Murel', V. I. Shashkin, and S. Rushworth
pp. 11-13 Full Text: PDF (53 kB)
Features of GaN Growth Attained by Metal–Organic Vapor-Phase Epitaxy in a Low-Pressure Reactor
O. I. Khrykin, A. V. Butin, D. M. Gaponova, V. M. Danil'tsev, M. N. Drozdov, Yu. N. Drozdov, A. V. Murel, and V. I. Shashkin
pp. 14-16 Full Text: PDF (53 kB)
LOW-DIMENSIONAL SYSTEMS
Effect of an Interfacial Oxide Layer on the Electroluminescence Efficiency of Metal–Quantum-Confined Semiconductor Heterostructures
N. V. Baidus', P. B. Demina, M. V. Dorokhin, B. N. Zvonkov, E. I. Malysheva, and E. A. Uskova
pp. 17-21 Full Text: PDF (125 kB)
Spectra of Persistent Photoconductivity in InAs/AlSb Quantum-Well Heterostructures
V. Ya. Aleshkin, V. I. Gavrilenko, D. M. Gaponova, A. V. Ikonnikov, K. V. Marem'yanin, S. V. Morozov, Yu. G. Sadofyev, S. R. Johnson, and Y.-H. Zhang
pp. 22-26 Full Text: PDF (76 kB)
Long-Time Photoluminescence Kinetics of InAs/AlAs Quantum Dots in a Magnetic Field
T. S. Shamirzaev, A. M. Gilinskii, A. K. Bakarov, A. I. Toropov, S. A. Figurenko, and K. S. Zhuravlev
pp. 27-29 Full Text: PDF (44 kB)
Electroluminescent Properties of Heterostructures with GaInNAs Quantum Wells
A. V. Murel', V. M. Danil'tsev, Yu. N. Drozdov, D. M. Gaponova, V. I. Shashkin, V. B. Shmagin, and O. I. Khrykin
pp. 30-32 Full Text: PDF (49 kB)
A Study of Recombination Centers Related to As–Sb Nanoclusters in Low-Temperature Grown Gallium Arsenide
P. N. Brunkov, A. A. Gutkin, Yu. G. Musikhin, V. V. Chaldyshev, N. N. Bert, S. G. Konnikov, V. V. Preobrazhenskii, M. A. Putyato, and B. R. Semyagin
pp. 33-36 Full Text: PDF (71 kB)
Effect of the Electrochemical Modification of a Thin Ga(In)As Cap Layer on the Energy Spectrum of InAs/GaAs Quantum Dots
I. A. Karpovich, A. V. Zdoroveishchev, S. V. Tikhov, P. B. Demina, and O. E. Khapugin
pp. 37-40 Full Text: PDF (57 kB)
Intersubband Absorption of Light in Heterostructures with Double Tunnel-Coupled GaAs/AlGaAs Quantum Wells
L. E. Vorob'ev, V. Yu. Panevin, N. K. Fedosov, D. A. Firsov, V. A. Shalygin, V. V. Kapaev, S. Hanna, S. Schmidt, E. A. Zibik, and A. Seilmeier
pp. 41-43 Full Text: PDF (52 kB)
Current Oscillations under Lateral Transport in GaAs/InGaAs Quantum Well Heterostructures
A. V. Antonov, V. I. Gavrilenko, E. V. Demidov, B. N. Zvonkov, and E. A. Uskova
pp. 44-49 Full Text: PDF (90 kB)
Optical Phenomena in InAs/GaAs Heterostructures with Doped Quantum Dots and Artificial Molecules
L. E. Vorob'ev, V. Yu. Panevin, N. K. Fedosov, D. A. Firsov, V. A. Shalygin, A. A. Andreev, Yu. B. Samsonenko, A. A. Tonkikh, G. E. Cirlin, N. V. Kryzhanovskaya, V. M. Ustinov, S. Hanna, A. Seilmeier, N. D. Zakharov, and P. Werner
pp. 50-53 Full Text: PDF (76 kB)
Calculation of the States of Shallow Donors in Quantum Wells in a Magnetic Field Using Plane Wave Expansion
V. Ya. Aleshkin and L. V. Gavrilenko
pp. 54-57 Full Text: PDF (49 kB)
The Effect of the Localization in a Quantum Well on the Lifetime of the States of Shallow Impurity Centers
E. E. Orlova, P. Harrison, W.-M. Zhang, and M. P. Halsall
pp. 58-61 Full Text: PDF (65 kB)
Cyclotron Resonance in Doped and Undoped InAs/AlSb Heterostructures with Quantum Wells
V. Ya. Aleshkin, V. I. Gavrilenko, A. V. Ikonnikov, Yu. G. Sadofyev, J. P. Bird, S. R. Johnson, and Y.-H. Zhang
pp. 62-66 Full Text: PDF (65 kB)
Terahertz Luminescence of GaAs-Based Heterostructures with Quantum Wells under the Optical Excitation of Donors
N. A. Bekin, R. Kh. Zhukavin, K. A. Kovalevskii, S. G. Pavlov, B. N. Zvonkov, E. A. Uskova, and V. N. Shastin
pp. 67-72 Full Text: PDF (77 kB)
Efficient Near IR Photoluminescence from Gallium Nitride Layers Doped with Arsenic
A. V. Andrianov, S. V. Novikov, I. S. Zhuravlev, T. Li, R. Xia, S. Bull, I. Harrison, E. C. Larkins, and C. T. Foxon
pp. 73-76 Full Text: PDF (64 kB)
Properties of Structures Based on Laser-Plasma Mn-Doped GaAs and Grown by MOC-Hydride Epitaxy
Yu. V. Vasil'eva, Yu. A. Danilov, Ant. A. Ershov, B. N. Zvonkov, E. A. Uskova, A. B. Davydov, B. A. Aronzon, S. V. Gudenko, V. V. Ryl'kov, A. B. Granovsky, E. A. Gan'shina, N. S. Perov, and A. N. Vinogradov
pp. 77-81 Full Text: PDF (71 kB)
A Study of the Properties of the Structures with Al Nanoclusters Incorporated into the GaAs Matrix
N. V. Vostokov, S. A. Gusev, V. M. Danil'tsev, M. N. Drozdov, Yu. N. Drozdov, A. I. Korytin, A. V. Murel, and V. I. Shashkin
pp. 82-85 Full Text: PDF (161 kB)
InGaAs/GaAs Quantum Dot Heterostructures for 3–5 µm IR Detectors
A. V. Antonov, D. M. Gaponova, V. M. Danil'tsev, M. N. Drozdov, L. D. Moldavskaya, A. V. Murel', V. S. Tulovchikov, and V. I. Shashkin
pp. 86-88 Full Text: PDF (48 kB)
Study of the Photoelectric Properties of Ge Quantum Dots in a ZnSe Matrix on GaAs
I. G. Neizvestny, S. P. Suprun, and V. N. Shumsky
pp. 89-94 Full Text: PDF (80 kB)
Unusual Persistent Photoconductivity in the InAs/AlSb Quantum Well
Yu. G. Sadofyev, A. Ramamoorthy, J. P. Bird, S. R. Johnson, and Y.-H. Zhang
pp. 95-99 Full Text: PDF (66 kB)
Special Features of Structural Interaction in (AlGaIn)N/GaN Heterostructures Used as Dislocation Filters
I. P. Soshnikov, N. N. Ledentsov, A. F. Tsatsul'nikov, A. V. Sakharov, W. V. Lundin, E. A. Zavarin, A. V. Fomin, D. Litvinov, E. Hahn, and D. Gerthsen
pp. 100-102 Full Text: PDF (160 kB)
Lateral Photoconductivity of AlGaAs/InGaAs Structures with Quantum Wells and Self-Organized Quantum Dots Under Interband Illumination
O. A. Shegai, A. K. Bakarov, A. K. Kalagin, and A. I. Toropov
pp. 103-106 Full Text: PDF (56 kB)
Spin Effects in Magnetoresistance Induced in an n-InxGa1 – xAs/GaAs Double Quantum Well by a Parallel Magnetic Field
M. V. Yakunin, G. A. Al'shanskii, Yu. G. Arapov, V. N. Neverov, G. I. Kharus, N. G. Shelushinina, B. N. Zvonkov, E. A. Uskova, A. de Visser, and L. Ponomarenko
pp. 107-112 Full Text: PDF (80 kB)
Terahertz Oscillator Based on Nonlinear Frequency Conversion in a Double Vertical Cavity
Yu. A. Morozov, I. S. Nefedov, V. Ya. Aleshkin, and I. V. Krasnikova
pp. 113-118 Full Text: PDF (83 kB)
Localization of Holes in an InAs/GaAs Quantum-Dot Molecule
M. M. Sobolev, G. E. Cirlin, Yu. B. Samsonenko, N. K. Polyakov, A. A. Tonkikh, and Yu. G. Musikhin
pp. 119-123 Full Text: PDF (89 kB)
AMORPHOUS, VITREOUS, AND POROUS SEMICONDUCTORS
The Engineering and Properties of InAs Quantum Dot Molecules in a GaAs Matrix
Yu. B. Samsonenko, G. E. Cirlin, A. A. Tonkikh, N. K. Polyakov, N. V. Kryzhanovskaya, V. M. Ustinov, L. E. Vorob'ev, D. A. Firsov, V. A. Shalygin, N. D. Zakharov, P. Werner, and A. Andreev
pp. 124-126 Full Text: PDF (108 kB)
Resonant Raman Scattering and Atomic Force Microscopy of InGaAs/GaAs Multilayer Nanostructures with Quantum Dots
M. Ya. Valakh, V. V. Strelchuk, A. F. Kolomys, Yu. I. Mazur, Z. M. Wang, M. Xiao, and G. J. Salamo
pp. 127-131 Full Text: PDF (176 kB)
Photoluminescence and the Raman Scattering in Porous GaSb Produced by Ion Implantation
Yu. A. Danilov, A. A. Biryukov, J. L. Gonçalves, J. W. Swart, F. Iikawa, and O. Teschke
pp. 132-135 Full Text: PDF (109 kB)
Efficiency of Avalanche Light-Emitting Diodes Based on Porous Silicon
S. K. Lazarouk, A. A. Leshok, V. A. Labunov, and V. E. Borisenko
pp. 136-138 Full Text: PDF (52 kB)
PHYSICS OF SEMICONDUCTOR DEVICES
Observation of the Middle-Infrared Emission from Semiconductor Lasers Generating Two Frequency Lines in the Near-Infrared Region of the Spectrum
V. Ya. Aleshkin, V. I. Gavrilenko, S. V. Morozov, K. V. Marem'yanin, B. N. Zvonkov, and S. M. Nekorkin
pp. 139-141 Full Text: PDF (53 kB)
The Resonant Terahertz Response of a Slot Diode with a Two-Dimensional Electron Channel
V. V. Popov, G. M. Tsymbalov, M. S. Shur, and W. Knap
pp. 142-146 Full Text: PDF (61 kB)
Bloch Oscillations in Superlattices: The Problem of a Terahertz Oscillator
Yu. A. Romanov and Yu. Yu. Romanova
pp. 147-155 Full Text: PDF (111 kB)
The Mode Competition, Instability, and Second Harmonic Generation in Dual-Frequency InGaAs/GaAs/InGaP Lasers
V. Ya. Aleshkin, B. N. Zvonkov, S. M. Nekorkin, and Vl. V. Kocharovsky
pp. 156-159 Full Text: PDF (59 kB)Archived web conten
A-15 type superconducting hydride : Nanograined structure with low strain, strong electron-phonon interaction, and moderate level of nonadiabaticity
Get PDFFor seven decades by A-15 superconductors we meant metallic alloys (where A is a transition metal, and B is groups IIIB and IVB element) discovered by Hardy and Hulm (Phys. Rev. 89, 884 (1953)). Nb3Ge exhibited the highest superconducting transition temperature, , among these alloys. One of these alloys, , is primary material in modern applied superconductivity. Recently Guo et al (arXiv:2307.13067) extended the family of superconductors where the metallic ions arranged in the beta tungsten (A-15) sublattice by observation of in phase compressed at . Despite the has much lower in comparison with near-room-temperature superconducting phase ( at ) discovered by Drozdov et al (Nature 569, 531 (2019)), the holds the record high within A-15 family. Cross et al (Phys. Rev. B 109, L020503 (2024)) confirmed the high-temperature superconductivity in the compressed . In this paper, we analyzed available experimental data measured in and found that this superconductor exhibits nanograined structure, 5.5 nm < D < 35 nm, low crystalline strain < 0.003, high electron-phonon coupling constant, 1.5 < < 2.55, and moderate level of the nonadiabaticity . We found that derived and values for the phase are similar to the ones in cuprates, pnictides, and near-room-temperature superconductors and , which implies that the phase falls to unconventional superconductors band in the Uemura plot.43 pages, 12 figures + 3 figures in Supplementary Material
Fusion product studies via fast ion D-D and D-3He fusion on JET
No full textDedicated fast ion D-D and D-3He fusion experiments were performed on JET with carbon wall (2008) and ITER-like wall (2014) for testing the upgraded neutron and energetic ion diagnostics of fusion products. Energy spectrum of D-D neutrons was the focus of the studies in pure deuterium plasmas. A significant broadening of the energy spectrum of neutrons born in D-D fast fusion was observed, and dependence of the maximum D and D-D neutron energies on plasma density was established. Diagnostics of charged products of aneutronic D-3He fusion reactions, 3.7 MeV alpha-particles similar to those in D-T fusion, and 14.6 MeV protons, were the focus of the studies in D-3He plasmas. Measurements of 16.4 MeV gamma-rays born in the weak secondary branch of D(3He, γ)5Li reaction were used for assessing D-3He fusion power. For achieving high yield of D-D and D-3He reactions at relatively low levels of input heating power, an acceleration of D beam up to the MeV energy range was used employing 3rd harmonic () ICRH technique. These results were compared to the techniques of D beam injection into D-3He mixture, and 3He-minority ICRH in D plasmas
Doctrine of Love in Writings of 14th-Century Persian Mystic Mahmud Kashani
Get PDFThe article is devoted to the work of Mahmud Kashani (d. 735/1334-35), who was a sheikh of the Suhravardiya Sufi order and the author of several significant works. The object of analysis was one of the parts of his most famous work — the prose treatise “The lamp that indicates the true path, and the key to a sufficient amount [of mystical knowledge]”. The article deals with the religious views and scientific heritage of Mahmud Kashani. A commented translation of part of the first section “On Love” from the tenth chapter “Explanation of mystical states” of the specified work is proposed. Since Mahmud Kashani is also credited with the poem “Treasures of Secrets and Symbols of the Righteous”, dedicated to the psychological aspects of mystical love, we have also translated one of its chapters. Comparison of fragments of these works shows significant discrepancies in the explanation of love, which may be due to the fact that the author expounds the concept of love of ascetic Sufism in the first essay, and Sufism “based on love” in the second. The second direction goes back to the composition of the “Revelation of Love” by the Persian mystical philosopher Ahmad Ghazali. It is also possible that ‘Izz ad-Din Mahmud is not the author of the poem “Treasures of Secrets…”
Measurement of circulating transcripts and gene cluster analysis predicts and defines therapeutic efficacy of peptide receptor radionuclide therapy (PRRT) in neuroendocrine tumors
No full textBackground Peptide receptor radionuclide therapy (PRRT) is an effective method for treating neuroendocrine tumors (NETs). It is limited, however, in the prediction of individual tumor response and the precise and early identification of changes in tumor size. Currently, response prediction is based on somatostatin receptor expression and efficacy by morphological imaging and/or chromogranin A (CgA) measurement. The aim of this study was to assess the accuracy of circulating NET transcripts as a measure of PRRT efficacy, and moreover to identify prognostic gene clusters in pretreatment blood that could be interpolated with relevant clinical features in order to define a biological index for the tumor and a predictive quotient for PRRT efficacy. Methods NET patients (n = 54), M: F 37:17, median age 66, bronchial: n = 13, GEP-NET: n = 35, CUP: n = 6 were treated with Lu-177-based-PRRT (cumulative activity: 6.5-27.8 GBq, median 18.5). At baseline: 47/54 low-grade (G1/G2; bronchial typical/atypical), 31/49 (18)FDG positive and 39/54 progressive. Disease status was assessed by RECIST1.1. Transcripts were measured by real-time quantitative reverse transcription PCR (qRT-PCR) and multianalyte algorithmic analysis (NETest); CgA by enzyme-linked immunosorbent assay (ELISA). Gene cluster (GC) derivations: regulatory network, protein:protein interactome analyses. Statistical analyses: chi-square, non-parametric measurements, multiple regression, receiver operating characteristic and Kaplan-Meier survival. Results The disease control rate was 72 %. Median PFS was not achieved (follow-up: 1-33 months, median: 16). Only grading was associated with response (p < 0.01). At baseline, 94 % of patients were NETest-positive, while CgA was elevated in 59 %. NETest accurately (89 %, chi(2) = 27.4; p = 1.2 x 10(-7)) correlated with treatment response, while CgA was 24 % accurate. Gene cluster expression (growth-factor signalome and metabolome) had an AUC of 0.74 +/- 0.08 (z-statistic = 2.92, p < 0.004) for predicting response (76 % accuracy). Combination with grading reached an AUC: 0.90 +/- 0.07, irrespective of tumor origin. Circulating transcripts correlated accurately (94 %) with PRRT responders (SD+PR+CR; 97 %) vs. non-responders (91 %). Conclusions Blood NET transcript levels and the predictive quotient (circulating gene clusters+grading) accurately predicted PRRT efficacy. CgA was non-informative
Síntese, caracterização e estudo de novos complexos de Európio(III) e Térbio (III), contendo como ligantes a [1,2,5]tiadiazolo[3,4-f][1,10]fenantrolina e derivados de pirazolonas
Get PDFDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Físicas e Matemáticas, Programa de Pós-Graduação em Química, Florianópolis, 2010Neste trabalho foi sintetizado o ligante [1,2,5]tiadiazolo[3,4-f][1,10]fenantrolina, TDPHEN, juntamente com os ligantes derivados da pirazolona. Com estes ligantes foram obtidos novos compostos de coordenação de íons lantanídeos (Eu3+ e Tb3+). Os mesmos foram caracterizados mediante a determinação do ponto de fusão, análise da composição elementar, voltametria cíclica, espectroscopia de absorção nas regiões UV-vis e Infravermelho e espectroscopia de emissão. Para aqueles compostos nos quais foi possível obter bons cristais, (cristais únicos ou monocristais) sua caracterização foi feita por difração de raio#X. Também foram feitas as análises termogravimétricas (TGA), para determinar a estabilidade térmica dos compostos de coordenação sintetizados. O estudo eletroquímico permitiu obter os valores de - 4,07, - 4,17, - 4,09, - 4,23 eV e # 3,34, - 3,17, - 3,32, - 3,34 eV HOMO e LUMO e de suas diferenças de energia #band gap# 0,73, 1,0, 0,77 e 0,89 eV para os complexos Eu(TDPHEN)(AMPP)3(H2O)3 20, Tb(TDPHEN)(AMPP)3(H2O) 21, Eu(TDPHEN)(AMFPP)3 22 e Tb(TDPHEN)(AMFPP)3 23. As propriedades fotofísicas foram analisadas através de seus espectros de absorção UV-vis e emissão, quer seja em solução quer no estado sólido, no qual os espectros de emissão exibiram bandas características dos íons lantanídeos, sendo em 546 nm (5D4 . 7F5) e 613 nm (5D0 . 7F2) para Térbio e Európio respectivamente. Os complexos 22 e 23 estão octa-coordenados com seus respectivos ligantes, os complexos 20 e 21 além de seus ligantes, também possuem água em suas esferas de coordenação. Os complexos de Eu+3 e Tb+3 apresentam uma estrutura de cristalização triclínico. Os valores médios das ligações entre Eu-O e Eu-N foram 2,35 e 2,61 Å e para Tb-O e Tb-N foram 2,33 e 2, 58 Å.In the present work [1,2,5]thiadiazolo[3,4-f][1,10]phenanthroline TDPHEN and some ligands based on pyrazolone derivatives were synthesized. These ligands were used to obtain new complexes of Terbium (III) and Europium (III). The mentioned complexes were characterized by melting point, infrared spectroscopy, elemental analysis (CHNS). Two of the four synthesized complexes gave fine crystals and were also characterized by X-ray diffraction. Furthermore the thermal stabilities of these complexes were determined by TGA. The electrochemical study obtained values of - 4.07, - 4.17, - 4.09, - 4.23 eV and - 3.34, - 3.17, - 3.32, - 3.34 eV for HOMO and LUMO and their differences in energy 'band gap' 0.73, 1.0, 0.77 and 0.89 eV for the complexes Eu(TDPHEN)(AMPP)3(H2O)3 20, Tb(TDPHEN)(AMPP)3(H2O) 21, Eu(TDPHEN)(AMFPP)3 22 and Tb(TDPHEN)(AMFPP)3 23. The photophysical properties were analyzed by UV-Vis absorption and emission spectra in solution and in solid estate. The emission spectra exhibit the characteristic peaks of the lanthanide ions at 546 nm (5D4 . 7F5) and 613 nm (5D0 . 7F2) for Terbium and Europium respectively. Complexes 22 and 23 are octa-coordinated with their respective ligands. The complexes 20 and 21 also present as their ligands water in their spheres of coordination. The complex Eu(III) and Tb(III) have a structure of crystallization triclinic. The average values of the connections between Eu-O and Eu-N were 2.35 and 2.61 Å and Tb-O and Tb-N were 2.33 and 2, 58 Å
Electron-phonon coupling constant and BCS ratios in (La,Nd)-H superhydride
Get PDFStoichiometric near room-temperature superconductors (i.e., and
) exhibit so high ground state upper critical field, , that the magnetic phase diagram in these materials cannot be measured in
non-destructive experiments. However, recently, Semenok et al (arXiv2203.06500)
proposed the idea to explore full magnetic phase diagram in NRTS samples in
which the superconducting order parameter is suppressed by the magnetic element
doping. If the element is uniformly distributed in the material, then the
theory of the electron-phonon mediated superconductivity predicts the
suppression of the order parameter in three-dimensional s-wave superconductor.
Semenok et al (arXiv2203.06500) experimentally proved this idea by substituting
La with the magnetic rare earth Nd in the . As a
result, in the (x=0.09) decreases to Tc~120 K,
and the upper critical field decreases to . While the
exact hydrogen content should be further established in the
(because similar suppression was observed in
hydrogen deficient reported by Drozdov et al (2019 Nature 569
528)), a significant part of the full magnetic phase diagram for
(x=0.09) was measured. Here we analyzed reported
Semenok et al (arXiv2203.06500) data for (x=0.09)
compressed at P=180 GPa and deduced: (a) Debye temperature, ; (b) the electron-phonon coupling constant, ; (c) the
ground state superconducting energy gap, ; (d) the
gap-to-transition temperature ratio, ; and (e) the
relative jump in specific heat at , . The deduced values
indicate that (x=0.09; P=180 GPa) is moderately strong
coupled s-wave superconductor.Comment: 13 pages, 3 figure
PRRT neuroendocrine tumor response monitored using circulating transcript analysis: the NETest
No full textPurpose: Peptide receptor radionuclide therapy (PRRT) is effective for metastatic/inoperable neuroendocrine tumors (NETs). Imaging response assessment is usually efficient subsequent to treatment completion. Blood biomarkers such as PRRT Predictive Quotient (PPQ) and NETest are effective in real-time. PPQ predicts PRRT efficacy; NETest monitors disease. We prospectively evaluated: (1) NETest as a surrogate biomarker for RECIST; (2) the correlation of NETest levels with PPQ prediction. Methods: Three independent 177Lu-PRRT-treated GEP-NET and lung cohorts (Meldola, Italy: n = 72; Bad-Berka, Germany: n = 44; Rotterdam, Netherlands: n = 41). Treatment response: RECIST1.1 (responder (stable, partial, and complete response) vs non-responder). Blood sampling: pre-PRRT, before each cycle and follow-up (2–12 months). PPQ (positive/negative) and NETest (0–100 score) by PCR. Stable < 40; progressive > 40). CgA (ELISA) as comparator. Samples de-identified, measurement and analyses blinded. Kaplan–Meier survival and standard statistics. Results: One hundred twenty-two of the 157 were evaluable. RECIST stabilization or response in 67%; 33% progressed. NETest significantly (p < 0.0001) decreased in RECIST “responders” (− 47 ± 3%); in “non-responders,” it remained increased (+ 79 ± 19%) (p < 0.0005). NETest monitoring accuracy was 98% (119/122). Follow-up levels > 40 (progressive) vs stable (< 40) significantly correlated with mPFS (not reached vs. 10 months; HR 0.04 (95%CI, 0.02–0.07). PPQ response prediction was accurate in 118 (97%) with a 99% accurate positive and 93% accurate negative prediction. NETest significantly (p < 0.0001) decreased in PPQ-predicted responders (− 46 ± 3%) and remained elevated or increased in PPQ-predicted non-responders (+ 75 ± 19%). Follow-up NETest categories stable vs progressive significantly correlated with PPQ prediction and mPFS (not reached vs. 10 months; HR 0.06 (95%CI, 0.03–0.12). CgA did not reflect PRRT treatment: in RECIST responders decrease in 38% and in non-responders 56% (p = NS). Conclusions: PPQ predicts PRRT response in 97%. NETest accurately monitors PRRT response and is an effective surrogate marker of PRRT radiological response. NETest decrease identified responders and correlated (> 97%) with the pretreatment PPQ response predictor. CgA was non-informative
A Damage model for the ductile failure analysis of plastic components
Get PDFTese (doutorado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Engenharia Mecânica, Florianópolis, 2011O objetivo deste trabalho é propor um modelo matemático e um sistema computacional, baseado no método dos elementos finitos, capaz de auxiliar a atividade de análise estrutural de componentes de plástico submetidos à falha dúctil. Basicamente, este sistema computacional será composto por um modelo elasto-viscoplástico acoplado ao dano, a fim de ser possível descrever a evolução das deformações inelásticas e os processos degradativos que conduzirão à falha e, assim, auxiliar no dimensionamento de componentes. O referido modelo foi desenvolvido sob as teorias propostas por Lemaitre [1], Fremond e Nedjar [2] e sob as abordagens da termodinâmica dos meios contínuos e do método do estado local, onde foram introduzidos os conceitos de potenciais termodinâmicos e de variáveis de estado. Ao se utilizar estas abordagens, assegura-se que os modelos produzirão resultados termodinamicamente consistentes. A fim de certificar o modelo proposto e validar o sistema numérico, realizou-se um ensaio uniaxial, em que o corpo de provas foi deformado até a sua fratura. Os dados obtidos do referido ensaio e de outros ensaios complementares foram utilizados na identificação das propriedades e constantes materiais, que definem o modelo proposto. Os procedimentos experimentais foram realizados no Departamento de Fibras e Tecnologia de Polímeros do Instituto Real de Tecnologia (KTH), em Estocolmo, Suécia.The objective of this work is to propose a mathematical model and a numerical scheme, based on the finite element method, to be used to analyze mechanical components manufactured with plastic material, subjected to monotonic loading conditions that undergo a ductile failure. Basically, this numerical scheme will be composed by an elasto-viscoplastic model coupled with a non-local damage theory, in order to describe the evolution of the inelastic strains and the damaging processes of the material, which will consequently lead to the failure of the component. The cited model has been developed by means of the theories proposed by Lemaitre [1], Fremond and Nedjar [2], among others, and makes use of the method of local state variables and is derived within the scope of the consistent thermodynamics of the continuum medium. The main advantage of using these approaches is the confidence they give that the models can not produce thermodynamically unreasonable results. In order to attest the proposed model and to validate the numerical scheme, one considers an experimental uniaxial test, in which the specimen is deformed up to its ductile fracture. The data obtained from the given experimental uniaxial test and from other complementary experimental tests is then employed for the identification of the material properties and parameters, which define the proposed damage model. The experimental procedures have been performed at the Fibre and Polymer Technology Department of the Royal Institute of Technology (KTH), in Stockholm, Sweden
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