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Photo-Catalytic Degradation of Trichlorophenol with UV/Sulfite/ZnO Process, Simultaneous Usage of Homogeneous Reductive and Heterogeneous Oxidative Agents generator as a New Approach of Advanced Oxidation/Reduction Processes (AORPs)
摘要： This study develops UV/Sulfite/ZnO (USZ) photoreactor, as a novel method of Advanced Oxidation/Reduction Processes (AORPs), and employs it for degradation, dechlorination and mineralization of 2,4,6-trichlorophenol (TCP) content of wastewaters. Degradation efficiency of the UV-only, UV/ZnO, UV/Sulfite and USZ processes were determined as 23.4%, 37.6%, 44.8% and 87.83% respectively, at 10 min reaction time, 50 mg L-1 TCP concentration and pH of 7. Findings indicated that TCP degrades completely within 15 min treatment of 50 mg L-1 initial TCP concentration. According to Molar ratio evaluations, 1:2:50 is the optimal Molar ratio of sulfite/ZnO/TCP in the USZ process. Analyzing effluents of the USZ reactor by liquid chromatography/mass spectroscopy after 5, 10 and 15 min reaction time revealed that TCP decomposes to ring-shaped compounds in less than 10 min and all TCP and its metabolites convert to linear compounds within 15 min reaction time. Also fourteen little fragments were identified in the degradation of TCP by USZ during 2.5 till 15 min of reaction time. Investigating kinetic of the process through a pseudo first-order model using 10 to 200 mg L-1 TCP over 1 to 15 min reaction time demonstrated that the observed rate constant (kobs) decreases from 0.3811 to 0.0824 min-1 and the observed TCP degradation rate (robs) increases from 3.811 to 16.48 mg L-1 min-1 with increase of TCP concentration. Furthermore, electrical energy consumption (EEO) of the USZ process was calculated with kinetic model 2.21 to 10.25 as 2.19 to 3.55 and with merit-figure model 4.94 to 12.39 kW h m-3 from 10 to 200 mg L-1, respectively. In addition, the effect of co-existing water anions on degradation of 50 mg L-1 TCP was explored during 30 min processing. While 100% degradation was achieved in the absence of any anion, adding nitrate, as the most effective anion, decreased TCP degradation to 78.24%. The highest dechlorination was observed at sulfite/ZnO Molar ratio 1:2 and pH 11.0. Mineralization of TCP by USZ process was achieved 33.2 % after 15 min of reaction.
关键词： Metabolites,Co-existing,Photoreactor,Degradation,Energy consumption,Kinetic
更新于2025-09-23 15:22:29
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Simultaneous photocatalytic reduction/degradation of divalent nickel/naphthalene pollutants in aqueous solutions
摘要： Toxic heavy metals and organic pollutants are simultaneously exist in the wastewater of some industries. This study explores reduction of toxic divalent nickel ions, from either nitrate or sulfate salts, coupled with naphthalene (NA) degradation using titania photocatalyst in an efficient photo-sono reactor. A synergism appears when reduction and degradation treatments perform simultaneously in the media. With initial concentrations of [Ni(II)]0 = 5 mg/L and [NA]0 = 10 mg/L, under dominant mild conditions, removal efficiencies of 54.5% and 56.6% were corresponding to Ni(II) and NA when nickel nitrate was used, respectively. These efficiencies were enhanced to 59.2% and 57.5% with nickel sulfate, all after 90 min operations. For evaluating the mechanism of reactions, reactive oxygen species analysis on solutions as well as FTIR, SEM and BET analysis on the titania nanoparticles, before and after usage, were performed. The reaction kinetic was also followed for individual species in the mixed solution and accordingly, the energy consumption was evaluated for one order of magnitude decrease in pollutants concentration. The high performance of the used method was revealed in comparison to the similar reported reduction/degradation processes.
关键词： divalent nickel,kinetic,energy consumption,naphthalene,photocatalytic treatment
更新于2025-09-23 15:22:29
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Optical Response of Lumped-Element Kinetic-Inductance Detector Arrays
摘要： We present an analysis of the optical response of lumped-element kinetic-inductance detector arrays, based on the NIKA2 1 mm array. This array has a dual-polarization sensitive Hilbert inductor for directly absorbing incident photons. We present the optical response calculated from a transmission line model, simulated with HFSS and measured using a Fourier transform spectrometer. We have estimated the energy absorbed by individual component of a pixel, such as the inductor. The difference between the absorption efficiencies is expected to be 20% from the simulations. The Fourier-transform spectroscopy measurement, performed on the actual NIKA2 arrays, validates our simulations. We discuss several possible ways to increase the absorption efficiency. This analysis can be used for optimization of the focal plane layout and can be extended to other kinetic inductance detector array designs in millimeter, submillimeter, and terahertz frequency bands.
关键词： superconducting microresonator,optical response,millimeter astronomy,Kinetic inductance detector
更新于2025-09-23 15:22:29
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Atomic layer deposition of titanium nitride for quantum circuits
摘要： Superconducting thin films with high intrinsic kinetic inductance are of great importance for photon detectors, achieving strong coupling in hybrid systems, and protected qubits. We report on the performance of titanium nitride resonators, patterned on thin films (9–110 nm) grown by atomic layer deposition, with sheet inductances of up to 234 pH/(cid:2). For films thicker than 14 nm, quality factors measured in the quantum regime range from 0.2 to 1.0 (cid:2) 106 and are likely limited by dielectric two-level systems. Additionally, we show characteristic impedances up to 28 kX, with no significant degradation of the internal quality factor as the impedance increases. These high impedances correspond to an increased single photon coupling strength of 24 times compared to a 50 X resonator, transformative for hybrid quantum systems and quantum sensing.
关键词： superconducting thin films,atomic layer deposition,quantum circuits,titanium nitride,kinetic inductance
更新于2025-09-23 15:21:21
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Introducing a quantum kinetic model using the generalized Boltzmann equation in the complex phase space
摘要： In the present work, using the generalized Boltzmann equation of the ?rst author [Phys. Rev. E 94, 023316 (2016)], a quantum kinetic model in the complex phase space is proposed. Employing the Chapman-Enskog analysis and applying the Wick rotation (using complex-valued relaxation time), it is shown that the present model recovers the time-dependent Schr?edinger equation, while preserving the main features of the conventional lattice Boltzmann models, e.g., simplicity of implementation, second-order accuracy (in space), and convenience in parallel programming. The present results are numerically veri?ed by simulating three benchmark problems.
关键词： quantum kinetic model,Schr?dinger equation,Wick rotation,lattice Boltzmann models,generalized Boltzmann equation,Chapman-Enskog analysis,complex phase space
更新于2025-09-23 15:21:21
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The Structure of Iron Powder Aggregation Obtained by Selective Laser Melting
摘要： A powder of different fractional composition was obtained from the iron ingot using the melt atomization method, from which samples for further studies were grown on the EOSint M270 unit using the selective laser melting (SLM) method. When considering the thin sections of the samples, we observed equiaxed recrystallized grains up to 20 μm in size, randomly distributed particles in the form of fragments up to 5 μm in size and equally oriented non-axial crystallites, forming groups in the form of arcuate layers with a front width of 800 μm and depth from 10 to 30 microns. Between them, narrow zones of increased chemical content were found, which are interpreted as probable traces of the stoppages of thermal fronts. We recorded traces of mass localized microplastic flow in the form of extended (up to 350x40 μm) and curved microregions with unequal-sized grains bordering microregions filled with equiaxial recrystallized grains due to the action of non-uniform thermal fields. Thus, in metal objects produced by the SLM, the complex morphology of the structure indicates a combination of different-scale mechanisms of structural changes. It has been established that in non-stationary temperature conditions of structure formation, the role of kinetic processes increases.
关键词： powdered iron,kinetic processes,selective laser melting,additive technologies
更新于2025-09-23 15:21:01
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Stepped morphology on vicinal 3C- and 4H-SiC (0001) faces: A Kinetic Monte Carlo study
摘要： Stepped morphologies on vicinal 3C- and 4H-SiC (0001) surfaces with the miscut toward [1100] or [1120] directions have been studied with a three-dimensional kinetic Monte Carlo model. In the model, a three-dimensional lattice mesh was established based on the crystal lattice of 3C-and 4H-SiC to fix the positions of atoms and interatomic bonding. Periodic boundary conditions were applied in the lateral direction while helicoidal boundary conditions were used in the direction of crystal growth. Events, such as adatoms attachment, detachment and interlayer transport at the step edges, and adatoms adsorption and diffusion on the terraces were considered in the model. Effects of Ehrlich-Schwoebel barriers at downward step edges and incorporation barriers at upwards step edges were also considered. Moreover, the atoms of silicon and carbon were treated as the minimal diffusing species independently to achieve more elaborate information for the behavior of atoms in the crystal surface. The simulation results showed that multiple-height steps were formed on the vicinal 4H-SiC (0001) surfaces, whereas single bilayer-height stepped morphologies were observed on the vicinal 3C-SiC (0001) surfaces. Furthermore, zigzag shaped edges were observed for both of 3C- and 4H-SiC (0001) surfaces with the miscut toward [1120] direction. At last, the formation mechanism of the stepped morphology was also analyzed.
关键词： Computer simulation,Crystal morphology,Silicon Carbide,Surfaces,Kinetic Monte Carlo Model
更新于2025-09-23 15:21:01
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Suppression of radiation loss in high kinetic inductance superconducting co-planar waveguides
摘要： We present a lab-on-chip technique to measure the very low losses in superconducting transmission lines at (sub-) mm wavelengths. The chips consist of a 100 nm-thick NbTiN Co-planar Waveguide (CPW) Fabry–P(cid:2)erot (FP) resonator, coupled, on one side, to an antenna and, on the other side, to a Microwave Kinetic Inductance detector. Using a single frequency radiation source allows us to measure the frequency response of the FP around 350 GHz and deduce its losses. We show that the loss is dominated by radiation loss inside the CPW line that forms the FP and that it decreases with the decreasing linewidth and increasing kinetic inductance as expected. The results can be quantitatively understood using SONNET simulations. The lowest loss is observed for a CPW with a total width of 6 lm and corresponds to a Q-factor of (cid:2)15 000.
关键词： radiation loss,Fabry–P(cid:2)erot resonator,co-planar waveguides,superconducting transmission lines,kinetic inductance
更新于2025-09-23 15:21:01
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Deuterium Kinetic Isotope Effect in the Photocatalyzed Dissociation of Methanol on TiO2(110)
摘要： Deuterium kinetic isotope effect (KIE) in the photochemistry of methanol on TiO2(110) has been studied to find the rate-determining step (RDS) and understand the reaction mechanism using two-photon photoemission spectroscopy (2PPE). Deuterium substitution of the methyl hydrogen has little effect on the kinetics of this reaction, suggesting that neither the break of the C-H(D) bond nor the transfer of H(D) atoms to the bridging sites is the RDS in the transformation of methanol into formaldehyde. In contrast, the reaction rate of MeOH is ~1.3 times of that of MeOD, suggesting that the cleavage of O-H(D) is the RDS in the photocatalyzed dissociation of methanol on TiO2(110). The results contradict with the common fact that C-H(D) is more difficult to break than O-H(D) based on ground state energetics, implying the involvement of photogenerated charge carriers in the reaction of C-H break whereas the cleavage of O-H is likely a thermal reaction. Difference in the activation energy of O-H and O-D dissociation reaction in the methanol/TiO2(110) system has been calculated based on the KIE measurements. Our work is consistent with the fact that methoxy is photocatalytically more reactive than methanol, and suggests that the conversion of methanol into methoxy is crucial in the photochemistry of methanol on TiO2(110) and probably other metal oxide semiconductor surfaces.
关键词： two-photon photoemission spectroscopy,photocatalyzed dissociation,Deuterium kinetic isotope effect,TiO2(110),methanol
更新于2025-09-23 15:21:01
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Increased multiplexing of superconducting microresonator arrays by post-characterization adaptation of the on-chip capacitors
摘要： We present an interdigitated capacitor trimming technique for fine-tuning the resonance frequency of superconducting microresonators and increasing the multiplexing factor. We first measure the optical response of the array with a beam mapping system to link all resonances to their physical resonators. Then, a new set of resonance frequencies with uniform spacing and higher multiplexing factor is designed. We use simulations to deduce the lengths that we should trim from the capacitor fingers in order to shift the resonances to the desired frequencies. The sample is then modified using contact lithography and re-measured using the same setup. We demonstrate this technique on a 112-pixel aluminum lumped-element kinetic-inductance detector array. Before trimming, the resonance frequency deviation of this array is investigated. The variation of the inductor width plays the main role for the deviation. After trimming, the mean fractional frequency error for identified resonators is (cid:1)6.4 (cid:2) 10(cid:1)4, with a standard deviation of 1.8 (cid:2) 10(cid:1)4. The final optical yield is increased from 70.5% to 96.7% with no observable crosstalk beyond (cid:1)15 dB during mapping. This technique could be applied to other photon-sensitive superconducting microresonator arrays for increasing the yield and multiplexing factor.
关键词： interdigitated capacitor trimming,lumped-element kinetic-inductance detector,superconducting microresonators,multiplexing factor,resonance frequency tuning
更新于2025-09-23 15:21:01