•MPAC coupled with UV and US irradiations was applied to efficient decompose of H2O2.•Over 87% of COD removed and the effluent was permissible to discharge environment.•Recalcitrant compounds were ...removed effectively and the biodegradability improved.•MPAC indicated high catalytic activity, reusability and stability in treatment process.
An effective hybrid system was applied as a first report for successful treatment of recalcitrant petrochemical wastewater (PCW). In this regards, magnetic powdered activated carbon (MPAC), as a heterogeneous catalyst, was coupled with ultrasound (US) and UV irradiations for activation of H2O2 (marked as MPAC/US/UV/H2O2). Chemical oxygen demand (COD) removal ratio was evaluated with various influencing operating factors including solution pH, MPAC and H2O2 concentrations, US power and quenchers. A possible mechanism for catalytic degradation and generation of reactive species was proposed. To evaluate the biodegradability of both raw and treated PCWs, the activated sludge inhibition experiments were performed based on Zahn-Wellens test. MPAC indicated high catalytic activity, reusability and stability in the studied system. Over 87% of COD was removed under optimum conditions within 80 min treatment and the residual COD concentration reached 82.9 mg/L, which was permissible to discharge surface water sources based on the environmental standards. Leaching of transition metals from catalyst textural was negligible. Compared to homogeneous system (Fe2+/US/UV/H2O2), heterogeneous system (MPAC/US/UV/H2O2) represented a better performance in COD removal. Identification of intermediates by GC–MS showed that a wide range of recalcitrant compounds was removed and/or degraded into small molecular compounds effectively after treatment. A biodegradability ratio of 64% and the residual COD of 28 mg/L for treated PCW, indicating that the biodegradability was improved and refractory organic matters removed effectively. As conclusion, MPAC/US/UV/H2O2 hybrid system can be introduced as a successful advanced treatment process for efficient remediation of refractory PCWs.
Abstract
At the intersection of quantum theory and relativity lies the possibility of a clock experiencing a superposition of proper times. We consider quantum clocks constructed from the internal ...degrees of relativistic particles that move through curved spacetime. The probability that one clock reads a given proper time conditioned on another clock reading a different proper time is derived. From this conditional probability distribution, it is shown that when the center-of-mass of these clocks move in localized momentum wave packets they observe classical time dilation. We then illustrate a quantum correction to the time dilation observed by a clock moving in a superposition of localized momentum wave packets that has the potential to be observed in experiment. The Helstrom-Holevo lower bound is used to derive a proper time-energy/mass uncertainty relation.
Renewable energy resources are often known as cost-effective and lucrative resources and have been widely developed due to environmental-economic issues. Renewable energy utilization even in small ...scale (e.g., microgrid networks) has attracted significant attention. Energy management in microgrid can be carried out based on the generating side management or demand side management. In this paper, portable renewable energy resource are modeled and included in microgrid energy management as a demand response option. Utilizing such resources could supply the load when microgrid cannot serve the demand. This paper addresses energy management and scheduling in microgrid including thermal and electrical loads, renewable energy sources (solar and wind), CHP, conventional energy sources (boiler and micro turbine), energy storage systems (thermal and electrical ones), and portable renewable energy resource (PRER). Operational cost of microgrid and air pollution are considered as objective functions. Uncertainties related to the parameters are incorporated to make a stochastic programming. The proposed problem is expressed as a constrained, multi-objective, linear, and mixed-integer programing. Augmented Epsilon-constraint method is used to solve the problem. Final results and calculations are achieved using GAMS24.1.3/CPLEX12.5.1. Simulation results demonstrate the viability and effectiveness of the proposed method in microgrid energy management.
•Introducing portable renewable energy resource (PRER) and considering effect of them.•Considering reserve margin and sensitivity analysis for validate robustness.•Multi objective and stochastic management with considering various loads and sources.•Using augmented Epsilon-constraint method to solve multi objective program.•Highly decreasing total cost and pollution with PRER in stochastic state.
Abstract The increasing integration of microgrids into distribution networks has highlighted the significance of evaluating and managing intelligent microgrids from both technical and economic ...perspectives. In this paper, a decentralized approach using agents is employed to optimize the operation of an intelligent microgrid within the telecommunications platform. The decentralized control method comprises two layers. The first layer represents the main microgrid, which includes loads and their controllers, as well as renewable and conventional resources. In the secondary layer, there is a telecommunication platform in which agents can operate as a control processor along with the means of communication. It should be noted that agents interact with the primary layer and neighbouring agents and exchange information with each other. This exchange takes place until the best state of optimization for the power supply occurs. In this study, the operation cost is calculated for decentralized control rules and considering telecommunication links. Also, the effect of performance on cost reduction is examined and compared with normal conditions and centralized methods. It can be seen that the operation cost of the network has decreased to 9.034% after the implementation of the mentioned method in comparison with the normal condition and it has decreased to 6.957% in comparison with the centralized method. Then, using a demand side management program, the cost will be reduced by 2.5%. In the next step, the uncertainty of available resources is taken into account where the uncertainties increase the cost by 7.8%.
By analyzing the failure mechanisms, crashworthiness characteristics of FW composite tubes subjected to two modes of progressive damage and catastrophic failure are investigated using acoustic ...emission technique and numerical method. The AE signals of ±45° composite tubes were classified using hierarchical and wavelet transform methods, and based on the realistic and three-dimensional geometrical architecture of tubular structures, the microstructural finite element model was developed using Catia and ABAQUS software. Then deformation patterns and the impression of each mechanism on the crashworthiness characteristics were assessed. Results indicated that fiber breakage and fiber/matrix debonding could likely control the higher percentage of damage. By changing the type of modes from progressive damage to catastrophic failure, the percentage of matrix cracking increases, the fiber/matrix separation decreases, and the failure behavior become dominated by local buckling. Comparing the FE simulation with experimental results, we found the proposed 3D model can reasonably predict the pre-crushing, post-crushing, and material densification.
Photocatalytic degradation of tetracycline using MWCNT/TiO2nanocomposite was investigated under UVC irradiation. The effective operational parameters included pH, irradiation time, photocatalyst ...dosage, weight ratio of MWCNT to TiO2 and tetracycline concentration and were studied consecutively. Complete removal of tetracycline concentrations of up to 10 mg/L was obtained at MWCNT to TiO2 ratio of 1.5 (w/w%), pH 5, photocatalyst dosage of 0.2 g/L. Pseudo-first order kinetic model was best fitted with the experimental results (R2: 0.91–0.98 for different tetracycline concentrations). Based on TOC analysis, mineralization was 37% in the same reaction conditions for initial tetracycline concentration of 10 mg/L and reached to 83% after 300 min. In the case of real pharmaceutical wastewater, the COD concentration of 2267 mg/L decreased to 342 mg/L after 240 min in the same operational conditions.
•Photocatalytic degradation of tetracycline using MWCNT/TiO2 nano-composite was studied under UVC irradiation.•MWCNT/TiO2 nano-composite was synthesized and fully characterized.•Complete removal of tetracycline concentration of 10 mg/L was observed in pH 5, photocatalyst dosage of 0.2 g/L and irradiation time of 100 min.•Real pharmaceutical wastewater was effectively treated by UVC/MWCNT-TiO2 photocatalytic process.
Occurrence and frequency of six most prescribed antibiotics (tetracycline, norfloxacin, azithromycin, anhydro erythromycin, cephalexin, and amoxicillin) were assessed in three wastewater treatment ...plants (WWTPs), and in water and sediments of the Persian Gulf at Bushehr coastline, Iran. The antibiotics concentration in the influent and effluent of septic tank (the hospital WWTP), activated sludge (the hospital WWTP), and stabilization pond (municipal WWTP) ranged between 7.89 and 149.63, 13.49–198.47, 6.55–16.37 ng/L, respectively. Conventional treatment resulted in incomplete removal of most of the studied antibiotics. Furthermore, the activated sludge was more effective in terms of antibiotic elimination compared to the stabilization pond or septic tank. The mean concentration of antibiotics ranged 1.21–51.50 ng/L in seawater and 1.40–25.32 ng/g in sediments during summer and winter. Norfloxacin was the dominant detected antibiotic in seawater, sediments, and influent of two hospital WWTPs. Seasonal comparisons showed significant differences for erythromycin and amoxicillin concentrations in seawater. Spatial variation indicated the role of physicochemical properties on distribution of antibiotics in seawater and sediments. The results emphasize the need to pay attention to antibiotic contamination in water and sediments of the Persian Gulf.
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•6 antibiotics occur in Persian Gulf, Iran (water: 0.8-89 ng/L, sediments: 1–118 ng/g).•Winter- and summer-time content of 2 antibiotics was different in seawater (p ˂ 0.05).•Direct correlation was seen between antibiotics and pH, TOC, Mg and K in water.•Processes in WWTPs showed antibiotics cannot be fully removed (0.1–88%).•Pseudo-partitioning coefficient (kd,s) of antibiotics was obtained 88–28,436 L/kg.
Phonon creation by gravitational waves Sabín, Carlos; Bruschi, David Edward; Ahmadi, Mehdi ...
New journal of physics,
08/2014, Volume:
16, Issue:
8
Journal Article
Peer reviewed
Open access
We show that gravitational waves create phonons in a Bose-Einstein condensate (BEC). A traveling spacetime distortion produces particle creation resonances that correspond to the dynamical Casimir ...effect in a BEC phononic field contained in a cavity-type trap. We propose to use this effect to detect gravitational waves. The amplitude of the wave can be estimated applying recently developed relativistic quantum metrology techniques. We provide the optimal precision bound on the estimation of the waveʼs amplitude. Finally, we show that the parameter regime required to detect gravitational waves with this technique could be, in principle, within experimental reach in a medium-term timescale.
This article generalizes the conditional probability interpretation of time in which time evolution is realized through entanglement between a clock and a system of interest. This formalism is based ...upon conditioning a solution to the Wheeler-DeWitt equation on a subsystem of the Universe, serving as a clock, being in a state corresponding to a time
t
. Doing so assigns a conditional state to the rest of the Universe
|
ψ
S
(
t
)
⟩
, referred to as the system. We demonstrate that when the total Hamiltonian appearing in the Wheeler-DeWitt equation contains an interaction term coupling the clock and system, the conditional state
|
ψ
S
(
t
)
⟩
satisfies a time-nonlocal Schrödinger equation in which the system Hamiltonian is replaced with a self-adjoint integral operator. This time-nonlocal Schrödinger equation is solved perturbatively and three examples of clock-system interactions are examined. One example considered supposes that the clock and system interact via Newtonian gravity, which leads to the system's Hamiltonian developing corrections on the order of
G
/
c
4
and inversely proportional to the distance between the clock and system.
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