A template-based liquid phase deposition was applied to fabricate SnO2 nanotube arrays. The prepared SnO2 nanotube photocatalysts were characterized using X-ray diffraction (XRD), field-emission ...electron microscopy (FE-SEM), transmission electron microscope (TEM), UV–Vis absorb spectrum, and Brunauer-Emmett-Teller (BET) measurements. The results showed that the well-crystalled rutile-SnO2 nanotube arrays with an inner diameter of about 60 nm and a wall thickness of about 20 nm can be fabricated at calcination temperature of 600 °C. In addition, the photocatalytic activity of the SnO2 nanotubes calcined at different temperatures for degradation of methylene blue (MB) dye under UV light illumination was investigated. The results clearly indicated that the samples calcined at 600 °C exhibited the highest photocatalytic activity, which makes them ideal for applications in environmental remediation. It was suggested that the enhanced photocatalytic efficiency of the SnO2 nanotubes may be due to their high specific surface area as-well-as their increased crystallinity with increasing calcination temperature. On the basis of the characterization results, we proposed a possible mechanism for the photocatalytic degradation on SnO2 nanotubes.
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•SnO2 nanotubes were synthesized by alumina membrane-based liquid phase deposition.•The effect of calcination temperature on the photocatalytic degradation of methylene blue dye was studied.•The photocatalytic activity was enhanced with increasing calcination temperature.•Highest photodegradation efficiency was related to the nanotube calcined at 600 °C.•Probable mechanism for the photodegradation of MB by SnO2 nanotubes was elucidated.
The use of Reflectivity Curves and the Distance Gain Size (DGS) method are useful techniques for the sizing of discontinuities using Ultrasonics. The principal works on the theoretical relationship ...between the signal of a reflector at a specific distance and amplitude when compared to a known reflector. These assessments are typically carried out in two ways: • Use of Reflectivity Curves • DGS Software or Calculations This paper will cover the basis behind the development of these curves and the DGS system.
AbstractCorrosion is one of the most critical problems that impair the durability of RC structures. Both carbonation-induced and chloride-induced corrosion widely prevail in civil infrastructure ...around the globe. Expansive products are formed due to corrosion at the interface between concrete and reinforcing bar (rebar). The cracking and spalling in concrete due to expanding corrosion products and the reduction in the cross-sectional area of rebar jeopardize the safety and serviceability of RC structures. From an outsider perspective, this literature review summarizes the state of the art on the mechanisms of the two types of corrosion, mechanical degradation in RC structures as a result of these mechanisms, the analytical methods to predict the basic parameters most related to corrosion, and the available laboratory and field corrosion measurement techniques.
Manta Ray Foraging Optimization Algorithm (MRFO) is a new bio-inspired, meta-heuristic algorithm. MRFO algorithm has been used for the first time to optimize a multi-objective problem. The best size ...and location of distributed generations (DG) units have been determined to optimize three different objective functions. Minimization of active power loss, minimization of voltage deviation, and maximization of voltage stability index has been achieved through optimizing DG units under different power factor values, unity, 0.95, 0.866, and optimum value. MRFO has been applied to optimize DGs integrated with two well-known radial distribution power systems: IEEE 33-bus and 69-bus systems. The simulation results have been compared to different optimization algorithms in different cases. The results provide clear evidence of the superiority of MRFO that defind before (Manta Ray Foraging Optimization Algorithm. Quasi-Oppositional Differential Evolution Lévy Flights Algorithm (QODELFA), Stochastic Fractal Search Algorithm (SFSA), Genetics Algorithm (GA), Comprehensive Teaching Learning-Based Optimization (CTLBO), Comprehensive Teaching Learning-Based Optimization (CTLBO (ε constraint)), Multi-Objective Harris Hawks Optimization (MOHHO), Multi-Objective Improved Harris Hawks Optimization (MOIHHO), Multi-Objective Particle Swarm Optimization (MOPSO), and Multi-Objective Particle Swarm Optimization (MOWOA) in terms of power loss, Voltage Stability Index (VSI), and voltage deviation for a wide range of operating conditions. It is clear that voltage buses are improved; and power losses are decreased in both IEEE 33-bus and IEEE 69-bus system for all studied cases. MRFO algorithm gives good results with a smaller number of iterations, which means saving the time required for solving the problem and saving energy. Using the new MRFO technique has a promising future in optimizing different power system problems.
It is well known that luminescent conjugated polymers suffer serious loss of photoluminescence quantum yield (PLQY) in the solid state compared to dilute solution. This is due to efficient exciton ...migration in the solid, which enables the excitons to readily find low energy quenching sites. Here a new method to fabricate solid films with densely packed non‐interacting luminescent polymer chains, which yield very high PLQY and more astonishingly room temperature phosphorescence, is reported. Using water‐soluble conjugated polymers (WSCP) and polymeric surfactants such as poly(vinyl alcohol) (PVA) and poly(vinyl‐pyrrolidone) (PVP), films at 1:1 wt% or higher WSCP are produced and show room temperature phosphorescence; such behavior has never been observed before and clearly shows the very high degree of chain isolation that can be achieved in these hosts. The PVA or PVP not only breaks up WSCP aggregates in solution as an effective surfactant, PVA‐PVA or PVP‐PVP hydrogen bond formation upon drying locks in the isolation of the WSCP, avoiding segregation and yielding long time stability to these polymer/polymer nanomixtures. The method is found to work with a wide variety of WSCPs.
A new method to fabricate solid films with densely packed near perfectly isolated, non‐interacting luminescent polymer chains that yield very high photoluminescence quantum yield (PLQY) and, more remarkably, room temperature phosphorescence is reported. The method uses water‐soluble conjugated polymers (WSCP) and a polymeric surfactant such as poly(vinyl alcohol) (PVA) and poly(vinyl pyrrolidone) (PVP).
The endless problem of energy supplies are always floating on the surface. As a result, there are a daily improvement to optimize power generators, networks and system configuration. Renewable ...distributed generators (RDG) are in the heart of these developments. The size of RDG is increasing daily so, it must be optimized to maximize benefits and eliminate drawbacks. Optimization algorithms are one of the fast growing techniques. In this study the Manta Ray Foraging optimization algorithm (MRFO) is applied to minimize power losses through sizing and allocation of DG type I integrated into radial distribution network (RDN). The proposed technique was tested on three different networks, IEEE 33, 69 and 85 test systems. Also, three cases were assumed to evaluate the effectiveness of MRFO algorithm. The results were compared to recent applied techniques.
A simple but novel method is designed to study the characteristics of the exciplex state pinned at a donor–acceptor abrupt interface and the effect an external electric field has on these excited ...states. The reverse Onsager process, where the field induces blue‐shifted emission and increases the efficiency of the exciplex emission as the e–h separation reduces, is discussed.
We report the observations on the structural characterization and the optical properties of SnO
2
nanowires post-treated under different annealing temperatures (300, 400, 500 & 600 °C) for 1 h. ...Well-aligned SnO
2
nanowires with diameters of about 100-120 nm were deposited into alumina templates by means of the liquid phase deposition method. The X-ray diffraction (XRD) and Raman patterns of the prepared samples were indexed to the rutile phase of SnO
2
without any trace of an extra phase, which was further confirmed by transmission electron microscopy (TEM). The effect of annealing temperature on the optical properties of SnO
2
nanowires was studied by using UV-vis and luminescence spectral data. The UV-vis spectra indicated that the absorption edge is blue shifted as the annealing temperature is raised and the bandgap was determined to be 3.32 eV to 3.88 eV. Photoluminescence measurements showed a broad dominant emission peak in the visible region around 450-650 nm. This suggests that the visible emission can originate from defect-related states, particularly oxygen vacancies induced during the formation of SnO
2
nanowires.
We report the observations on the structural characterization and optical properties of SnO
2
nanowires post-treated under different annealing temperatures (300, 400, 500 & 600 °C) for 1 h.
In this document, the topic of discussion is the combination of two existing algorithms to generate a new hybrid technique. The two algorithms that are subjected to said amalgamation are Genetic ...Algorithms (GA) and Stain Bowerbird Optimization algorithms (SBO). These two methodologies have profound utility themselves and are used in a multitude of scenarios. The easy application and the constructive outcomes manifested by these two algorithms birthed the idea of their combined usage. Following up on this, the hybrid GASBO was created. GASBO was an optimization approach used to detect and categorize the allotted renewable energy assets in a specific energy generation complex. This was done to regulate the energy dispensing systems otherwise known as ‘distributing’ systems. These renewable resources are reflected by environmental factors and the energy they create is also dependent on their surroundings. Factors like sunlight, rain, waves, and tides etcetera play major roles in determining the outcome of the created energy.
Contrary to what it may appear like, the position of the DG sources in the structure affects the outcome a lot. These sources contain fuel cells and photovoltaic cells: in short, devices that can harness energy from a seemingly infinite supply like sunlight. As mentioned before, the GASBO assisted in providing the best location for the system and it also categorized the sources according to their abilities. The potential and position of the sources in the grid are of vast importance. The main purpose of GASBO is to optimize the overall system by improving its efficiency and reducing collateral harm. This shows that GASBO is quite a fundamental tool. It has also been tested on several systems like IEEE 33-bus. The facts in this paper are based on published projects.
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•Hybrid genetic algorithms (GA) and Satin bowerbird optimization (SBO) are applied.•The hybrid GASBO algorithm is applied for optimal allocation of DG in radial network.•Different scenarios were considered to address the accuracy of the GASBO algorithms.•The proposed algorithm is tested with two different radial networks.•The results approves the accuracy and efficiency of the proposed algorithm.
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