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Closed-loop functional optogenetic stimulation
摘要： Optogenetics has been used to orchestrate temporal- and tissue-specific control of neural tissues and offers a wealth of unique advantages for neuromuscular control. Here, we establish a closed-loop functional optogenetic stimulation (CL-FOS) system to control ankle joint position in murine models. Using the measurement of either joint angle or fascicle length as a feedback signal, we compare the controllability of CL-FOS to closed-loop functional electrical stimulation (CL-FES) and demonstrate significantly greater accuracy, lower rise times and lower overshoot percentages. We demonstrate orderly recruitment of motor units and reduced fatigue when performing cyclical movements with CL-FOS compared with CL-FES. We develop and investigate a 3-phase, photo-kinetic model to elucidate the underlying mechanisms for temporal variations in optogenetically activated neuromusculature during closed-loop control experiments. Methods and insights from this study lay the groundwork for the development of closed-loop optogenetic neuromuscular stimulation therapies and devices for peripheral limb control.
关键词： Functional stimulation,Photo-kinetic model,Motor units,Optogenetics,Neuromuscular control,Fatigue,Closed-loop control
更新于2025-09-23 15:23:52
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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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A novel kinetic model to estimate the agglomerate diameter formed by nano-sized Titania in emulsion region of AFBPR
摘要： To predict the agglomerate diameter formed by nano-sized Titania powders (P25) in emulsion region of annular fluidization bed photocatalytic reactor (AFBPR), a kinetic model was developed based on an assumption of a target molecule only reacts on the active site of an agglomerate in illumination field. The results indicated that the agglomerate diameter was a function of bed voidage and gas velocity for a given photocatalytic oxidation. It was obvious that the agglomerate diameter decreased with increasing bed voidage, and decreased along the heighten of fluidized bed, which were confirmed by the experimental results. The agglomerate size decreased with gas velocity increased, validated by the estimated data of force model. Finally, the veracity of kinetic model was validated by variation of gaseous compound types and their concentrations, which suggested that this kinetic model was feasible for photocatalytic oxidation of gaseous pollutants. This investigation highlights the novel method to describe the relationship between agglomerate diameter distribution formed in emulsion region of AFBPR and photocatalytic reactivity.
关键词： Kinetic model,Agglomerate,Bed voidage,Titania,Photocatalytic oxidation
更新于2025-09-23 15:21:01
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Degradation of carbamazepine by vacuum-UV oxidation process: Kinetics modeling and energy efficiency
摘要： Vaccum-ultraviolet (VUV) is effective for elimination of organic contaminants in aqueous environment and degradation of carbamazepine (CBZ) by VUV irradiation was systematically investigated in this study. A dynamic kinetic model was developed to simulate the destruction of CBZ that is mainly initiated by hydroxyl radicals (HO?). The second-order rate constant of the reaction between CBZ and HO? was determined to be 1.4×109 M-1 s-1. Effect of initial CBZ concentration, VUV irradiation intensity and natural organic matter (NOM) were further investigated in several batch experiments. The predicted CBZ removal rates increased with the increasing VUV intensity, while decreased with the increasing initial CBZ and NOM concentrations. Based on the electrical energy per order (EE/O) calculation, the optimal VUV intensity was determined to be 7.5×10-8 Einstein s-1. Meanwhile, several intermediates/products were identified and their time-dependent evolution profiles were determined, and finally a plausible degradation pathway of CBZ was proposed. Ecotoxicity assessment indicated that the potential toxicity of CBZ and its oxidation products should be paid more attention in the VUV process.
关键词： Kinetic model,Degradation pathway,Energy efficiency,Hydroxyl radical
更新于2025-09-19 17:15:36
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Kinetic modeling of spatio-temporal evolution of the gain in copper vapor active media
摘要： This paper addresses the theoretical study of the spatio-temporal gain profile of the copper vapor active media. The description of a kinetic model of a copper vapor amplifier which allows us to study spatio-temporal evolution of the amplifying characteristics is described. Using the kinetic model time and radial evolution of the medium optical gain and factors which governs the radial gain profile inhomogeneity of the brightness amplifier are shown.
关键词： brightness amplifier,laser radiation,laser monitor,beam profile,kinetic model,active optical system
更新于2025-09-19 17:15:36
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Green Synthesis of Nano Silver on TiO2 Catalyst for Application in Oxidation of Thiophene
摘要： The present research work describes the preparation of silver nanoparticles from silver nitrate, and Tulsi (Ocimum tenuiflorum) leaf extract, impregnation on titanium dioxide (TiO2) and evaluation of the catalytic activity of this nano silver impregnated TiO2 in the oxidation reaction of thiophene. Tertiary-butyl hydroperoxide was used as an oxidant in the reaction. The catalyst was characterized by BET, SEM, XRF, TEM, UV-Vis spectroscopy, XPS and TPR. The effect of process parameters such as speed of agitation, catalyst weight, oxidant to sulfur mole ratio, silver loading in the catalyst and temperature on the oxidation reaction was studied. Both pseudo-homogeneous and heterogeneous kinetic models were considered and applied for the result. The pseudo-homogeneous form of rate equation shows the reaction follows second order kinetics and is endothermic. Langmuir-Hinshelwood kinetic model is proposed, considering the reaction as a heterogeneous one with solid catalyst and found that surface reaction is the rate controlling step. This model is well fitted with experimental data.
关键词： Kinetic model,Tulsi leaf extract,Thiophene,Catalytic oxidation,Titanium dioxide,Silver nanoparticles
更新于2025-09-19 17:15:36
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Synergistic removal of ammonium by monochloramine photolysis
摘要： The presence of ammonium (NH4+) in drinking water treatment results in inhibition of disinfection efficiency and formation of nitrogenous disinfection by-products. Our previous study found monochloramine (NH2Cl) photolysis under 254 nm UV irradiation can be effective for removal of NH4+; however, the mechanisms of NH4+ degradation in this process were unknown. The kinetics and fundamental radical chemistry responsible for NH4+ removal in the UV/NH2Cl process were investigated in this study. The results showed that the pseudo first-order rate constant for NH4+ degradation in the UV/NH2Cl process ranged between 3.6 × 10?4 to 1.8 × 10?3 s?1. Solution pH affected radical conversion and a higher NH4+ degradation efficiency was achieved under acidic conditions. The effects of chloride were limited; however, the presence of either bicarbonate or natural organic matter scavenged radicals and inhibited NH4+ removal. NH2Cl photolysis generated an aminyl radical (NH2?) that further transformed to a chlorine dimer (Cl2??) and a hydroxyl radical (HO?). The second-order rate constants for Cl?, Cl2??, and HO? reacting with NH4+ were estimated as 2.59 × 108 M?1s?1, 3.45 × 105 M?1s?1, and 1.4 × 107 M?1s?1 at pH 3.9, respectively. Cl?, Cl2??, and HO? contributed 95.2%, 3.5%, and 1.3% to NH4+ removal, respectively, at the condition of 3 mM NH2Cl and pH 7.5. Major products included nitrite and nitrate, possibly accompanied by nitrogen-containing gases. This investigation provides insight into the photochemistry of NH4+ degradation in the UV/NH2Cl process and offers an alternative method for drinking water production.
关键词： Ammonium,Reactive chlorine radicals,UV/NH2Cl process,Kinetic model
更新于2025-09-19 17:15:36
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Dual-Wavelength (UV and Blue) Controlled Photopolymerization Confinement for 3D-Printing: Modeling and Analysis of Measurements
摘要： The kinetics and modeling of dual-wavelength (UV and blue) controlled photopolymerization con?nement (PC) are presented and measured data are analyzed by analytic formulas and numerical data. The UV-light initiated inhibition e?ect is strongly monomer-dependent due to di?erent C=C bond rate constants and conversion e?cacies. Without the UV-light, for a given blue-light intensity, higher initiator concentration (C10) and rate constant (k’) lead to higher conversion, as also predicted by analytic formulas, in which the total conversion rate (RT) is an increasing function of C1 and k’R, which is proportional to k’[gB1C1]0.5. However, the coupling factor B1 plays a di?erent role that higher B1 leads to higher conversion only in the transient regime; whereas higher B1 leads to lower steady-state conversion. For a ?xed initiator concentration C10, higher inhibitor concentration (C20) leads to lower conversion due to a stronger inhibition e?ect. However, same conversion ? b2C20]. Conversion of blue-only are much higher than that of UV-only and UV-blue combined, in which high C20 results a strong reduction of blue-only-conversion, such that the UV-light serves as the turn-o? (trigger) mechanism for the purpose of spatial con?rmation within the overlap area of UV and blue light. For example, UV-light controlled methacrylate conversion of a glycidyl dimethacrylate resin is formulated with a tertiary amine co-initiator, and butyl nitrite. The system is subject to a continuous exposure of a blue light, but an on-o? exposure of a UV-light. Finally, we developed a theoretical new ?nding for the criterion of a good material/candidate governed by a double ratio of light-intensity and concentration, [I20C20]/[I10C10].
关键词： additive manufacturing,kinetic model,photopolymerization,dual-wavelength,spatial con?rmation,3D printing
更新于2025-09-12 10:27:22