Co-electrophoretic deposition of Mn2O3/activated carbon on CuO nanowire array growth on copper foam as a binder-free electrode for high-performance supercapacitors

Journal of Materials Science: Materials in Electronics - The development of new materials with complex structures has proved to be an effective approach to improve their capabilities in a variety...     

Low temperature synthesis of Titanium diboride by carbothermal method

Titanium diboride powders have been synthesized by means of carbothermal reduction method utilizing Titanium oxide, Boric acid and Graphite. The effect of mechanical activation of mixed raw materials and the use of additional Boric acid on the final phases have been studied. The resultant powders were characterized by X-ray diffraction (XRD) analyzer and Field Emission Scanning Electron Microscope (FESEM). XRD patterns showed that TiB₂, TiC and C phases after heat treatment at stoichiometric ratio of reactants. By increasing the milling time, the unwanted phases such as C and TiC will be reduced. Pure TiB₂ could be synthesized with mechanical activation of raw materials for 24?h at non-stoichiometric ratio (using additional Boric acid) and heat treatment at low temperature of 1380?°C. In this condition, Titanium diboride could be achieved with residual carbon of 0.92 0.09wt% and mean average particle size of 3.28µm. Thermal analysis (TGA-DTA) was used to determine the reaction progress and mechanism. Results revealed that the intermediate phase, TiBO₃, played an important role in getting to lower temperature synthesis. This phase was identified after mechanical milling of raw materials and heat treatment at temperature of 1250?°C.     

A spatially explicit model of postdisaster housing recovery

Although postdisaster housing recovery is an important player in community recovery, its modeling is still in its infancy. This research aims to provide a spatial regression model for predicting households’ recovery decisions based on publicly available data. For this purpose, a hierarchical Bayesian geostatistical model with random spatial effects was developed. To calibrate the model, households’ data that were collected from Staten Island, New York, in the aftermath of Hurricane Sandy were used. The model revealed that on the scale of census tract, residents with higher income or larger household size were significantly less likely to reconstruct. In contrast, odds of reconstruction rose with increase of long‐term residents. The model outputs were also employed to develop a reconstruction propensity score for each census tract. The score predicts probability of reconstruction/repair in each tract versus others. The model was validated through comparison of the propensity scores with the distribution of Community Development Block Grant Disaster Recovery assistance and its resultant reconstruction. The validation indicated capability of the model to predict the potential hotspots of reconstruction. Accordingly, the propensity score can serve as a decision‐support tool to tailor recovery policies.     

Preparation and characterization of α-tocopherol nanocapsules based on gum Arabic-stabilized nanoemulsions

Food Science and Biotechnology - The preparation of water dispersed α-tocopherol nanocapsules through solvent-displacement technique using gum Arabic (GA) as natural stabilizing and...     

Effect of clinoptilolite on structure and drug release behavior of chitosan/thyme oil γ-Cyclodextrin inclusion compound hydrogels

Chitosan-based hydrogels involving γ-cyclodextrin inclusion compounds of thyme oil were prepared by freeze–thaw cycling method. Clinoptilolite as a natural zeolite was added to investigate its effects on the structural, mechanical, and drug release behaviors of the hydrogels. Zeolite compressed the structure and improved mechanical properties, which decreased swelling values. Release of thyme oil in prepared hydrogels were investigated by UV spectroscopy and drug release mechanism was evaluated by applying various mathematical methods. Rates of water vapor transmission of the samples were calculated as 2247–2998 g m⁻² day⁻¹ which are all in the range of an ideal wound dressing. Hydrogels with clinoptilolite had slower drug release (from 56% to 24% for hydrogels containing zeolite 1%) in comparison with that of without zeolite. Based on MTT assay, samples were low-toxic. Obtained results suggest that drug loaded hydrogels can be applied in biomedical field including drug delivery systems and wound dressings.     

Prediction of Concentration Profiles in an L‐Shaped Pulsed Extraction Column

The L‐shaped extraction pulsed plate column is believed to be able to perform under operating conditions between those of the vertical and the horizontal pulsed plate columns. It has an extraction efficiency similar to the vertical pulsed plate column. Here, the mass transfer performance of this novel column type was investigated and the application of three different models, i.e., the plug flow, the axial dispersion, and the back flow models, was evaluated to predict the solute concentration profile along the column length. The water‐acetone‐n‐butyl acetate and the water‐acetone‐toluene systems were used. The influence of the operational parameters on the height of the mass transfer unit and the back flow coefficients was evaluated using the back flow model. New correlations were proposed to predict the height of the mass transfer unit along with the back flow coefficients in each phase, which were in satisfactory agreement with the experimental data.     

Collective behavior of evaporating droplets on superhydrophobic surfaces

We study the evaporation dynamics of multiple water droplets deposited in ordered arrays or randomly distributed (sprayed) on superhydrophobic substrates (SHP) and smooth silicon wafers (SW). The evaluation of mass of the droplets as a function of time shows a power-law behavior with exponent 3/2, and from the prefactor of the power-law an evaporation rate can be determined. We find that the evaporation rate on a SHP surface is slower than a normal surface for both single droplet and collection of droplets. By dividing a large droplet into more smaller ones, the evaporation rate increases and the difference between the evaporation rates on SHP and SW surfaces becomes higher. The evaporation rates depend also on the distance of the droplets which increase with increasing this distance.     

Shape effect of cavity flameholder on mixing zone of hydrogen jet at supersonic flow

Cavity flameholder is known as an efficient technique for providing the ignition zone. In this research, computational fluid dynamic is applied to study the influence of the various shapes of cavity as flameholder on the mixing efficiency inside the scramjet. To evaluate different shapes of cavity flame holder, the Reynolds-averaged Navier–Stokes equations with (SST) turbulence model are solved to reveal the effect of significant parameters. The influence of trapezoidal, circle and rectangular cavity on fuel distribution is expansively analyzed. Moreover, the influence of various Mach numbers (M = 1.2, 2 and 3) on mixing rate and flow feature inside the cavity is examined. The comprehensive parametric studies are also done. Our findings show that the trapezoidal cavity is more efficient than other shapes in the preservation of the ignition zone within the cavity. In addition, the increase of free stream Mach number intensifies the main circulations within cavity and this induces a stable ignition zone within cavity.     

Mitochondrial Bioenergetics and Turnover during Chronic Muscle Disuse

Periods of muscle disuse promote marked mitochondrial alterations that contribute to the impaired metabolic health and degree of atrophy in the muscle. Thus, understanding the molecular underpinnings of muscle mitochondrial decline with prolonged inactivity is of considerable interest. There are translational applications to patients subjected to limb immobilization following injury, illness-induced bed rest, neuropathies, and even microgravity. Studies in these patients, as well as on various pre-clinical rodent models have elucidated the pathways involved in mitochondrial quality control, such as mitochondrial biogenesis, mitophagy, fission and fusion, and the corresponding mitochondrial derangements that underlie the muscle atrophy that ensues from inactivity. Defective organelles display altered respiratory function concurrent with increased accumulation of reactive oxygen species, which exacerbate myofiber atrophy via degradative pathways. The preservation of muscle quality and function is critical for maintaining mobility throughout the lifespan, and for the prevention of inactivity-related diseases. Exercise training is effective in preserving muscle mass by promoting favourable mitochondrial adaptations that offset the mitochondrial dysfunction, which contributes to the declines in muscle and whole-body metabolic health. This highlights the need for further investigation of the mechanisms in which mitochondria contribute to disuse-induced atrophy, as well as the specific molecular targets that can be exploited therapeutically.