An Experimental Investigation on Workability and Bleeding Behaviors of Cement Pastes Doped with Nano Titanium Oxide (n-TiO 2) Nanoparticles and FlyAsh

In this study,the workability of cement-based grouts containing n-TiO 2 nanoparticles and fly ash has been investigated experimentally.Several characteristic quantities(including,but not limited to,the marsh cone flow time,the mini slump spreading diameter and the plate cohesion meter value)have been measured for different percentages of these additives.The use of fly ash as a mineral additive has been found to result in improvements in terms of workability behavior as expected.Moreover,if nano titanium oxide is also used,an improvement can be obtained regarding the bleeding values for the cement-based grout mixes.Using such experimental data,a multi-layer perceptron artificial neural network model has been developed(5 neurons in the hidden layer of the network model have been developed using a total of 42 experimental data).70%of the data employed in this model have been used for training,15%for validation and 15%for the test phase.The results demonstrate that the artificial neural network model can predict Marsh cone flow time,mini slump spreading diameter and plate cohesion meter values with an average error of 0.15%.

Effect of nano-oxide layers on the magnetoresistance of ultrathin permalloy films

Ta/NiFe/Ta ultrathin films with and without nano-oxide layers （NOLs） were prepared by magnetron sputtering followed by a vacuum annealing process. The influence of NOLs on the magnetoresistance （MR） ratio of ultrathin permalloy films was studied. The results show that the influence of grain size and textures on the MR ratio becomes weak when the thickness of the NiFe layer is below 15 nm. A higher MR ratio was observed for the thinner （〈 15 nm） NiFe film with NOLs. The MR ratio of a 10 nm NiFe film can be remarkably enhanced by NOLs. The enhanced MR ratio for these ultrathin films can be attributed to the enhanced specular reflection of conduction electrons.

Effects of acetic acid on microstructure and electrochemical properties of nano cerium oxide films coated on AA7020-T6 aluminum alloy

Nano cerium oxide films were applied on AA7020-T6 aluminum alloy and the effects of acetic acid concentration on the microstructure and electrochemical properties of the coated samples were investigated by using scanning electron microscopy （SEM）, X-ray diffraction （XRD）, and potentiodynamic polarization methods. It has been found that by increasing the acetic acid/CeCl3·7H2O molar ratio, high uniform and crack-free films with well-developed grains were obtained and grain sizes of the films decreased. Elimination of cracks and decreasing grain size of the nano cerium oxide films caused corrosion resistance to increase.

The Effect of Titanium Nano Oxide and Heat Treatment on Physical Properties of Hornbeam (<i>Carpinus betulus</i>) in Golestan Province

The use of wood has been considered for a long time and to this day, it has a special place in human life. Modification of wood and lignocellulosic materials is done by various methods, including modification of physical, mechanical, chemical and thermal, that as a new technology, it leads to the improvement of their undesirable features. Among these methods, heat correction is a useful method to improve dimensional stability and leads to increased resistance to water absorption and decay. The main purpose of this study is to investigate the titanium Nano oxide and heat treatment on the physical properties of hornbeam species. Samples were saturated with titanium Nano oxide solution at a concentration of 5000 ppm and pressurized 7 times in a pressure tank. The samples were divided into three groups: control, heat and Nano thermal treatment. Heat and saturated samples with titanium Nano oxide were heat treated at three temperature levels of 150℃, 175℃ and 200℃ for 4 and 6 hours. All three groups underwent physical tests. Heat and Nano thermal oxide treatments led to reduced water absorption and thickness swelling. Comparison between heat and Nano thermal treatment showed a further decrease in water absorption and thickness swelling in Nano thermal samples.

Effect of Ultra-Turrax on Nanocellulose Produced by Acid Hydrolysis and Modified by Nano ZnO by Sol-Gel Method

Cellulose nanocrystals (NCC) and cellulose nanofibrils (CNF) were obtained by a single step process, with synergy between 64% sulfuric acid hydrolysis and high shear from ultra-turrax stirring, which is an advantageous process for disintegrating cellulose microcrystalline and also may improve the hydrolysis process. The surface modification on the cellulose was performed by the sol-gel process, in which the sulfate groups from hydrolysis were replaced by nanoparticles of zinc oxide, which led to the increase of up to 54&deg;C Tonset, according to thermogravimetric analysis (TGA) results. The morphology and crystallinity degree were characterized by Helium Ion Microscopy (HIM), atomic force microscopy (AFM) and X-ray diffraction. In addition, the ZnO band was observed in Fourier transform infrared spectroscopy, furthermore, the change in the zeta potential confirmed the cellulose modification. The changes in the values of proton spin-spin relaxation time for the systems showing the confined hydrogen in the rigid domains, confirmed the results observed with the aforementioned techniques, for both cellulose after hydrolysis and ZnO modified cellulose, suggesting that ZnO disrupted crystal formation in cellulose.

Multiphysics of multifunctional nanofluids based on different oxides nanoparticles and glycerol fluid

Nanofluid(NF)materials consisting of glycerol(Gly)and different inorganic nano oxides(TiO_(2),ZnO,Al_(2)O_(3),and SiO_(2) for the oxides concentration of 0.01 wt%to the weight of Gly base fluid)were prepared by a two-step method through ultrasonic cavitation process.These nanofluids were investigated by employing an X-ray diffractometer(XRD),ultraviolet-visible(UV-Vis)spectrophotometer,20 Hz to 1 MHz frequency range dielectric relaxation spectroscopy(DRS),ultrasonic interferometer,and rotational viscometer.The multiphysics of these nanofluids includes structural and optical properties,dielectric permittivity,electrical conductivity,conductivity relaxation,ultrasound velocity,adiabatic compress-ibility,acoustic impedance,viscosity,density,thermal conductivity,and viscoacoustic relaxation were characterized.The XRD patterns identified monodispersed and stable suspensions of these different characteristic nanoparticles in the hydrogen-bonded 3D supramolecular structure of ultra-high viscous glycerol fluid which were supported by their UV-Vis absorbance analyses.The energy band gap values of the TiO_(2)and ZnO containing nanofluids were found primarily ruled by the characteristic optical prop-erties of these oxides nanomaterials.The complex dielectric and various electrical functions studied at 25℃revealed that the suspension of different oxide nanoparticles in the glycerol fluid increased the static permittivity whereas reduced the direct current electrical conductivity which showed strong conductivity relaxation process dependence.The rheological measurements of the formulated nanofluids were performed over a shear rate range of 0.4-40 s^(-1)at temperatures of 25-55℃.The linear rela-tionship between shear rate and shear stress and also the shear rate-independent viscosity revealed the Newtonian behaviour of these nanofluids.The shear viscosity non-linearly decreased with the increase of temperature and exhibited the Arrhenius behaviour for all different oxides containing Gly-based nanofluids.The acoustic parameters of the nanofluids were altered unevenly with types of nano ox-ides and inferred some structure-property correlations.The promising technologically useable properties of these nanofluids were expected to impact their potential applications in optoelectronics,UV-blocking,sensing,nanodielectrics,energy storing and electric insulation,heat transfer systems,and also in ma-terials processing for the development of innovative soft condensed devices.

Impact assessment of biofouling resistant nano copper oxide-polyaniline coating on aquaculture cage nets

Biofouling is a major issue in aquaculture cages and nano materials based antifouling strategies became more prominent in recent years.Polyethylene aquaculture cage net surface which is modified with polyaniline and nano-copper oxide(CuO),reported to have biofouling resistance.Leaching of nano CuO from the net to the aquatic environment and its bioaccumulation in fish is the major concern against the technology adoption.The present study aimed to understand the accumulation of copper in fishes grown in a nano CuO treated aquaculture cage net.Studied the leaching pattern of nano CuO,biofouling inhibition and changes in strength of the cage net due to the nano CuO treatments.Fishes grown in the treated cages exhibited normal growth characteristics with no signs of abnormalities and also copper in their organs were within the prescribed standard limit.The CuO treated cage net exhibited excellent biofouling resistance and the percentage of occlusion of mesh by foulers were 56.77%more efficient than untreated cage net.Rate of nano CuO leached to the aquatic system was less than 8μg/g⋅d.The fouling organism assemblage on untreated and treated net was 18 and 11 species,respectively.Major calcareous shelled foulers were absent on treated nets.The study highlighted the potential application of nano CuO treatment to control biofouling in aquaculture cages.

High-temperature liquid Sn-air energy storage cell

A new type of a high temperature liquid metal-air energy storage cell based on solid oxide electrolyte has been successfully demonstrated at 750 ℃ by feeding metal Sn. In order to understanding the initial size effect of metal as a liquid fuel, we report here the impact of the thermal and electrochemical oxidation behavior of nano Sn （-100 nm）, comparing with micro-sized （-5 μm） and macro-sized （4350 μm） Sn. The thermogravimetric analysis and the monitoring OCV test indicate that the distinct property of nano-sized Sn results in a favorable thermal oxidation behavior near the melting point and a promising power performance due to enhanced fuel transport to the anode. However, the accumulated Sn oxide at the reaction interface during a discharge test towards the limitation of further electrochemical oxidation.

Adsorption Kinetic Properties of As(Ⅲ)on Synthetic Nano Fe-Mn Binary Oxides

The adsorptive removal of arsenic by synthetically-prepared nano Fe-Mn binary oxides（FM） was investigated. A novel method using potassium permanganate and ferric chloride as raw materials was used to synthesise FM. The molar ratio of Fe and Mn in the synthetic Fe-Mn binary oxides was 4 ： 3. The FM-1 and FM-2（prepared at different activation temperatures） having high specific surface areas（358.87 and 128.58 m^2/g, respectively） were amorphous and of nano particle types. The amount of arsenic adsorbed on FM-1 was higher than that adsorbed on FM-2 particles. After adsorption by FM-1, residual arsenic concentration decreased to less than 10 μg/L. The adsorption kinetics data were analyzed using different kinetic models including pseudo first-order model, pseudo second-order model, Elovich model and intraparticle diffusion model. Pseudo second-order kinetic model was the most appropriate model to describe the adsorption kinetics. The adsorption percentage of As（Ⅲ） increased in the p H range of 2–3 while it decreased with the increase of pH（ 3〈pH〈10）. The effects of coexisting anions on As（Ⅲ） removal using FM-1 and FM-2 were also studied and the order of the effects is as follows： NO_3^-, Cl-, F-〈SO_4^（2-）, HCO_3-〈H_2PO_4^-, indicating that H_2PO_4^- is the major competitor with As（Ⅲ） for adsorptive sites on the surface of the adsorbents. The higher adsorption capacity of FM-1 makes it potentially attractive adsorbent for the removal of As（Ⅲ） from groundwater.

Helium Bubble Growth in He^(+) Ions Implanted 304L Stainless Steel Processed by Laser Powder Bed Fusion During Post-Irradiation Annealing at 600℃

The abundancy of defect sinks in the microstructure of laser powder bed fusion(LPBF) processed austenitic stainless steels was found to be beneficial for helium resistance.In the current study,the influence of the novel microstructure in LPBF processed 304 L on the helium bubble growth behaviour was investigated using transmission electron microscopy in samples implanted with He^(+) ion and post-irradiation annealing treated at 600℃ for 1 h.Two variants of LPBF processed 304 L samples were used,one in as-built condition and the other solution-annealed.The comparison between the two samples indicated that the helium bubble growth was inhibited and remained stable in the as-built sample but coarsened significantly in the solution-annealed sample.The sub-grain boundaries and oxide nano-inclusions acted as defect sinks to trap helium atoms and inhibited the growth of helium bubble in the as-built sample under the post-irradiation annealing conditions used.