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1.
J Environ Manage ; 363: 121343, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38843727

RESUMO

This work presents a novel advanced oxidation process (AOP) for degradation of emerging organic pollutants - benzene, toluene, ethylbenzene and xylenes (BTEXs) in water. A comparative study was performed for sonocavitation assisted ozonation under 40-120 kHz and 80-200 kHz dual frequency ultrasounds (DFUS). Based on the obtained results, the combination of 40-120 kHz i.e., low-frequency US (LFDUS) with O3 exhibited excellent oxidation capacity degrading 99.37-99.69% of BTEXs in 40 min, while 86.09-91.76% of BTEX degradation was achieved after 60 min in 80-200 kHz i.e., high-frequency US (HFDUS) combined with O3. The synergistic indexes determined using degradation rate constants were found as 7.86 and 2.9 for LFDUS/O3 and HFDUS/O3 processes, respectively. The higher extend of BTEX degradation in both processes was observed at pH 6.5 and 10. Among the reactive oxygen species (ROSs), hydroxyl radicals (HO•) were found predominant according to scavenging tests, singlet oxygen also importantly contributed in degradation, while O2•- radicals had a minor contribution. Sulfate (SO42-) ions demonstrated higher inhibitory effect compared to chloride (Cl-) and carbonate (CO32-) ions in both processes. Degradation pathways of BTEX was proposed based on the intermediates identified using GC-MS technique.


Assuntos
Derivados de Benzeno , Benzeno , Ozônio , Poluentes Químicos da Água , Xilenos , Ozônio/química , Xilenos/química , Derivados de Benzeno/química , Benzeno/química , Poluentes Químicos da Água/química , Tolueno/química , Oxirredução , Água/química , Espécies Reativas de Oxigênio/química , Purificação da Água/métodos
2.
Phys Rev Lett ; 117(2): 020502, 2016 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-27447495

RESUMO

Displacement of propagating quantum states of light is a fundamental operation for quantum communication. It enables fundamental studies on macroscopic quantum coherence and plays an important role in quantum teleportation protocols with continuous variables. In our experiments, we have successfully implemented this operation for propagating squeezed microwave states. We demonstrate that, even for strong displacement amplitudes, there is no degradation of the squeezing level in the reconstructed quantum states. Furthermore, we confirm that path entanglement generated by using displaced squeezed states remains constant over a wide range of the displacement power.

3.
Phys Rev Lett ; 112(16): 160502, 2014 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-24815629

RESUMO

An experiment demonstrating a link between classical single-flux quantum digital logic and a superconducting quantum circuit is reported. We implement coupling between a moving Josephson vortex (fluxon) and a flux qubit by reading out of a state of the flux qubit through a frequency shift of the fluxon oscillations in an annular Josephson junction. The energy spectrum of the flux qubit is measured using this technique. The implemented hybrid scheme opens an opportunity to readout quantum states of superconducting qubits with the classical fluxon logic circuits.

4.
Nat Commun ; 14(1): 2896, 2023 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-37210421

RESUMO

The non-deterministic behavior of the Duffing oscillator is classically attributed to the coexistence of two steady states in a double-well potential. However, this interpretation fails in the quantum-mechanical perspective which predicts a single unique steady state. Here, we measure the non-equilibrium dynamics of a superconducting Duffing oscillator and experimentally reconcile the classical and quantum descriptions as indicated by the Liouvillian spectral theory. We demonstrate that the two classically regarded steady states are in fact quantum metastable states. They have a remarkably long lifetime but must eventually relax into the single unique steady state allowed by quantum mechanics. By engineering their lifetime, we observe a first-order dissipative phase transition and reveal the two distinct phases by quantum state tomography. Our results reveal a smooth quantum state evolution behind a sudden dissipative phase transition and form an essential step towards understanding the intriguing phenomena in driven-dissipative systems.

5.
Semin Arthritis Rheum ; 55: 152006, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35472664

RESUMO

BACKGROUND: The ASAS Health Index (ASAS HI) was developed to assess global functioning in patients with axial spondyloarthritis (axSpA). Influencing factors have not been studied to date, especially the influence of inflammation and structural changes in the spine has remained unclear to date. OBJECTIVE: To find out whether and to what degree do axial inflammation, radiographic damage and other clinical features influence global functioning of patients with axSpA. METHODS: Patient reported outcomes (ASAS HI, pain, BASDAI, BASFI, EQ-5D and SF-36) were assessed, spinal mobility by BASMI and depression by SF-36 scores. Axial inflammation was quantified using the MRI Berlin score and structural damage as detected by conventional radiographs by the modified Stokes AS Spinal Score (mSASSS). Correlation and regression analyses were performed to analyze the association between global functioning and other variables. RESULTS: A total of 191 axSpA patients with different degrees of global functioning and disease activity was included, 60.2% had r-axSpA. Syndesmophytes were found in 38.5% of patients - with a median mSASSS score of 3.8 (IQR 1.0-18.7) in r-axSpA and 0.0 (IQR 0.0-1.2) in nr-axSpA patients. The mean MRI score was 2.3 (IQR 0.5-7.6). ASAS HI values correlated significantly with BASMI, BASDAI, BASFI, BMI and MRI scores. However, no significant correlation was found for mSASSS and CRP. Regression analyses revealed that global functioning was significantly influenced by disease activity, physical function, obesity and depression but not by structural damage or spinal inflammation as detected MRI. CONCLUSIONS: Our study shows that global functioning is strongly associated with physical function, body weight and depression in patients with axSpA but not with spinal inflammation and structural damage. This may be explained by the relatively low mSASSS of these well treated patients.


Assuntos
Espondiloartrite Axial , Espondilartrite , Espondiloartropatias , Espondilite Anquilosante , Humanos , Inflamação/diagnóstico por imagem , Índice de Gravidade de Doença , Coluna Vertebral/diagnóstico por imagem , Espondilartrite/diagnóstico por imagem , Espondilartrite/tratamento farmacológico , Espondilite Anquilosante/tratamento farmacológico
6.
Sci Adv ; 7(52): eabk0891, 2021 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-34936429

RESUMO

The field of quantum communication promises to provide efficient and unconditionally secure ways to exchange information, particularly, in the form of quantum states. Meanwhile, recent breakthroughs in quantum computation with superconducting circuits trigger a demand for quantum communication channels between spatially separated superconducting processors operating at microwave frequencies. In pursuit of this goal, we demonstrate the unconditional quantum teleportation of propagating coherent microwave states by exploiting two-mode squeezing and analog feedforward over a macroscopic distance of d = 0.42 m. We achieve a teleportation fidelity of F = 0.689 ± 0.004, exceeding the asymptotic no-cloning threshold. Thus, the quantum nature of the teleported states is preserved, opening the avenue toward unconditional security in microwave quantum communication.

7.
J Hazard Mater ; 397: 122804, 2020 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-32450502

RESUMO

This study investigated - for the first time - the simultaneous degradation of benzene, toluene, ethylbenzene and o-xylene (BTEX) by persulfate (PS) and peroxymonosulfate (PMS) activated by asphaltenes (Asph) under ultrasound (US) irradiation. Advantageous properties such as high thermal stability, low production cost and extensive availability make asphaltenes as an appealing carbonaceous material for heterogeneous catalysis. The application of asphaltenes in PS/US increased the degradation of BTEXs from 31%, 34%, 35%, 32%-78%, 94%, 98% and 98%, while the removal of these compounds in PMS/US system was improved from 26%, 27%, 24%, 20%-76%, 91%, 97%, 97%, respectively. PS and PMS activation followed a typical sulfate-radical based advanced oxidation processes. In terms of activation of PS and PMS, the particles of asphaltenes intensified formation of reactive radicals by creating additional centers of cavitational events. Moreover, owing to π-π stacking interaction between asphaltenes and sp2-hybridized systems of BTEX, the contaminants undergo adsorption on the surface of asphaltenes and subsequent oxidation by formed radicals. The radical route of BTEX degradation in both PS/US/Asph and PMS/US/Asph systems was mainly contributed by sulfate (SO4•-) and hydroxyl radicals (HO•) and coexisting superoxide radical anions (O2•-) played a minor role.

8.
Phys Rev Lett ; 103(26): 260601, 2009 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-20366300

RESUMO

The computer simulations of fluctuational dynamics of an annular system governed by the sine-Gordon model with a white noise source are performed. It is demonstrated that the mean escape time (MET) of a phase string for an annular structure can be much larger than for a linear one and has a strongly pronounced maximum as a function of system's length. The location of the MET maximum roughly equals the size of the kink-antikink pair, which leads to evidence of a spatial crossover between two dynamical regimes: when the phase string escapes over the potential barrier as a whole and when the creation of kink-antikink pairs is the main mechanism of the escape process. For large lengths and in the limit of small noise intensity gamma, for both MET and inverse concentration of kinks, we observe the same dependence versus the kink energy E(k): approximately exp(2E(k)/gamma) for the annular structure and approximately exp(E(k)/gamma) for the linear one.

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