Nanoadsorbents have been regarded as promising materials for water treatment. The adsorption behaviour determines the applications of nanoadsorbents. In this reported work, the authors studied the adsorption behaviour...
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Nanoadsorbents have been regarded as promising materials for water treatment. The adsorption behaviour determines the applications of nanoadsorbents. In this reported work, the authors studied the adsorption behaviour of methylene blue on oxidised carbon nanoparticles (O-cNPs) in batch experiments. The adsorption data were fitted by the Freundlich model, rather than the Langmuir model. The kinetics studies indicated that it followed the pseudo-second-order model. The intraparticle diffusion model fitting suggested that the adsorption involved both intraparticle diffusion and surface diffusion. The adsorption was more effective at higher pH and lower ionic strength. The implication for the applications of O-cNPs in water treatment is discussed.
Biomass-derived porous carbon (Pc) loaded with precious metals have a synergistic enhancement effect on surface-enhanced Raman scattering (SERS). In this paper, Pccontaining various functional groups and large specif...
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Biomass-derived porous carbon (Pc) loaded with precious metals have a synergistic enhancement effect on surface-enhanced Raman scattering (SERS). In this paper, Pccontaining various functional groups and large specific surface area, good stability and certain biocompatibility were prepared using tomato skins and introduced into the preparation of Ag nanoflowers (NFs) SERS substrates. Rhodamine 6G (R6G) was used as the Raman probe molecule to evaluate the sensing performance of Ag NFs@Pc. The results showed that the stable dispersion and protective effect of Pc on Ag NPs significantly improved the sensitivity and long-term stability of traditional Ag NFs. In practical application, Ag NFs@Pc was further used to successfully achieve the quantitative analysis of trace methylene blue (10 ppt) and malachite green (10 ppt) in a lake water system. Therefore, SERS sensor Ag NFs@Pc is expected to become a promising candidate sensor for detecting in the field of environment and food monitoring.
The extreme thinness of graphene combined with its tensile strength made it a material appealing for discussing and even making complex cut-kirigami or folded-only origami. In the case of origami, its stability is mai...
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The extreme thinness of graphene combined with its tensile strength made it a material appealing for discussing and even making complex cut-kirigami or folded-only origami. In the case of origami, its stability is mainly defined by the positive energy of the single- or double-fold curvature deformation counterbalanced by the energy reduction due to favorable van der Waals contacts. These opposite sign contributions also have notably different scaling with the size L of the construction, the contacts contributing in proportion to area similar to L-2, single folds as similar to L, and highly strained double-fold corners as only similar to L-0 = const. computational analysis with realistic atomistic-elastic representation of graphene allows one to quantify these energy contributions and to establish the length scale, where a single fold is favored (7 nm < L < 21 nm) or a double fold becomes sustainable (L > 21 nm), defining the size of the smallest possible complex origami designs as L >> 21 nm.
Electrochemical techniques are becoming increasingly popular as a means of rehabilitating deteriorated reinforced concrete. In this paper we explore the possibility of using an electrodeposition technique for repairs ...
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Electrochemical techniques are becoming increasingly popular as a means of rehabilitating deteriorated reinforced concrete. In this paper we explore the possibility of using an electrodeposition technique for repairs of land-based cracked concrete structures and investigate the effect of this technique on various concrete properties. concrete specimens reinforced with steel rebars were used as test specimens in this study. The specimens were first precracked by exposing rebars to chloride-induced corrosion, and then immersed in a solution of zinc sulfate and subjected to a constant d.c. current. The current was applied between the reinforcing steel in the concrete and an external electrode immersed in the solution for eight weeks. The degree of crack closure, water permeability, condition of reinforcing steel, and chloride concentration were investigated in order to assess the effectiveness of this method as a potential rehabilitation technique. The results indicate that the formation of electrodeposits caused the closure of cracks and led to improvement of the concrete watertightness. In addition, the investigation shows that the application of the electrical current increases the passivity of steel in concrete.
The thermal buckling response of nanotubes with rotational restraints is investigated using a Timoshenko beam model with non-local elasticity theory. Two trigonometric (Fourier) series are selected to analyse the ther...
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The thermal buckling response of nanotubes with rotational restraints is investigated using a Timoshenko beam model with non-local elasticity theory. Two trigonometric (Fourier) series are selected to analyse the thermal buckling of the non-local Timoshenko nanotube with rotational restraints. Explicit equations are obtained for the boundary values with a coefficient matrix. In particular, the new method can be degenerated to the non-local Euler beam model by assigning proper value to the shear correction factor. The main advantage of the present technique is its capability of dealing with deformable or rigid supporting conditions. Several numerical examples are solved to asses proposed approach reliability. The results show that thermal buckling including the thermal effects are lower than those without the thermal effects when the temperature rises. The rotational restraint springs have significant effects on the buckling response of nanotubes.
High abrasion furnace black (HAF) filler has long been recognised as reinforcing filler, but the impact of concentration on dynamic mechanics performance and heat buildup of vulcanisates is rarely reported. Therefore,...
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High abrasion furnace black (HAF) filler has long been recognised as reinforcing filler, but the impact of concentration on dynamic mechanics performance and heat buildup of vulcanisates is rarely reported. Therefore, natural rubber (NR) composites filled by N330 with different concentration were prepared. Payne effect and heat buildup of HAF/NR composites increases with an increase of HAF loadings during to that filler network structure become stronger with an increase of HAF loadings. Moreover, tensile strength, tear strength as well as modulus increase with an increase of HAF loadings is attributed to better dispersion and improved interfacial interaction between HAF and NR matrices. The results reveal that composites with 60 per hundreds of rubber (phr) of HAF exhibit better overall mechanical properties and lower heat buildup.
Novel fluorescent carbon dots (cDs) were fabricated using the hydrothermal carbonisation method by peat, which is a very abundant and low-cost natural material in the world. The transmission electron microscopy images...
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Novel fluorescent carbon dots (cDs) were fabricated using the hydrothermal carbonisation method by peat, which is a very abundant and low-cost natural material in the world. The transmission electron microscopy images revealed that the peat-derived cDs (PcDs) are well-crystalline with an average size of 4 mm Fourier transform infrared and X-ray photoelectron spectra suggested large amounts of oxygenous functionality which made the synthesised PcDs water-soluble. The optical characterisations turned out that PcDs showed a stable and excellent excitation-dependent photoluminescence (PL), while the quantum yield was calculated to be 18.3%. As the PL of the PcDs could be efficiently quenched by ferric ions with a low-detection limit of 20 nM, the as-prepared PcDs could be employed as a highly fluorescent probe for ferric ions. Furthermore, the obtained PcDs have been successfully used for fluorescent imaging and Fe3+ detecting at cell level.
Nanoparticle Na3V2(PO4)(3)/c materials with different polyacrylonitrile contents can be successfully synthesized using precipitation method. As an energy storage material used in the production of lithium batteries wh...
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Nanoparticle Na3V2(PO4)(3)/c materials with different polyacrylonitrile contents can be successfully synthesized using precipitation method. As an energy storage material used in the production of lithium batteries which is also compared with pure of that, the Na3V2(PO4)(3)/c not only has a larger capacity, but also has a very high cycle stability. In particular, the initial discharge capacities of the Na3V2(PO4)(3)/c sample annealed at 750 degrees ccontaining 10 wt% of polyacrylonitrile are 130.9 and 122.2 mAh g(-1) at current densities of 0.5 and 1 c, respectively;the corresponding coulomb efficiencies are 97.3 and 99.5%. It is also worth noting that the capacity retention can reach as high as 92.7% for 500 cycles at 1 c.
In this study, graphene oxide (GO) was synthesized using Hummers, modified Hummers and improved Hummers methods, and then freestanding membranes were prepared based on these materials. Effects of different GO preparat...
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In this study, graphene oxide (GO) was synthesized using Hummers, modified Hummers and improved Hummers methods, and then freestanding membranes were prepared based on these materials. Effects of different GO preparation methods on c/O ratio and interlayer spacing of freestanding membranes were studied. Structure of these membranes was studied by X-ray diffraction, contact angle, XRF, FT-IR, and FESEM methods. Also, permeability of ammonia, dichloromethane, and water vapor was investigated through these membranes. Results showed that, the sample prepared by the Hummers method had lower c/O ratio, smoother surface and lower permeability for polar species, such as water and ammonia vapors, than nonpolar materials. Membranes prepared using Improved Hummers method showed the least permeability against nonpolar vapors such as dichloromethane.
The pyrolysis process enables the transformation of plastic waste into products such as oil, solid residue, and gas at temperatures of around 300-900 degrees c by thermal decomposition. conversion of such waste into v...
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The pyrolysis process enables the transformation of plastic waste into products such as oil, solid residue, and gas at temperatures of around 300-900 degrees c by thermal decomposition. conversion of such waste into valuable products depends on various factors, such as raw material composition, temperature, heating rate, residence time, and catalyst. From this point of view, in this study, predictions of gas product yield based on different pyrolysis conditions including waste types (LDPE-c/LDPE), temperature (400-600-800 degrees c), heating rate (5-10-20 degrees c/min), type of catalyst (zeolite-clay-sludge) and amount of catalyst (5%, 10%, 15%, by weight) were carried out with support from the vector regression (SVR) and the Gaussian process (GPR) models using the results of experimental studies performed under various conditions. Different kernel functions were used for SVR (Linear, Quadratic, cubic, Gaussian) and GPR (Squared Exponential, Matern 5/2, Exponential, Rational Quadratic). The Gaussian Kernel Function presented a good prediction performance (89% R-2 and 0.0011 RMSE) for SVR while the Exponential Kernel Function was the most appropriate for GPR (93% R-2 and 0.0011 RMSE). On the other hand, the deviations in the SVR model with linear Kernel change over a wide range of 0.25-80.85%, and the GPR model with exponential kernel show deviations close to each other in the range of 0.06-3.91%. The present study provides new information for future studies by understanding the pyrolysis process of plastic waste and predicting product yield.
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