Hierarchical 3D Cobalt‐Doped Fe3O4 Nanospheres@NG Hybrid as an Advanced Anode Material for High‐Performance Asymmetric Supercapacitors

Hierarchical nanostructure, high electrical conductivity, extraordinary specific surface area, and unique porous architecture are essential properties in energy storage and conversion studies. A new type of hierarchical 3D cobalt encapsulated Fe₃O₄ nanosphere is successfully developed on N‐graphene sheet (Co?Fe₃O₄ NS@NG) hybrid with unique nanostructure by simple, scalable, and efficient solvothermal technique. When applied as an electrode material for supercapacitors, hierarchical Co?Fe₃O₄ NS@NG hybrid shows an ultrahigh specific capacitance (775 F g^?1 at a current density of 1 A g^?1) with exceptional rate capability (475 F g^?1 at current density of 50 A g^?1), and admirable cycling performance (97.1% capacitance retention after 10 000 cycles). Furthermore, the fabricated Co?Fe₃O₄ NS@NG//CoMnO₃@NG asymmetric supercapacitor (ASC) device exhibits a high energy density of 89.1 Wh kg^?1 at power density of 0.901 kW kg^?1, and outstanding cycling performance (89.3% capacitance retention after 10 000 cycles). Such eminent electrochemical properties of the Co?Fe₃O₄ NS@NG are due to the high electrical conductivity, ultrahigh surface area, and unique porous architecture. This research first proposes hierarchical Co?Fe₃O₄ NS@NG hybrid as an ultrafast charge?discharge anode material for the ASC device, that holds great potential for the development of high‐performance energy storage devices.     

Development of a void ratio-moisture ratio-net stress framework for the prediction of the volumetric behavior of unsaturated granular materials

Despite extensive research on the behavior of unsaturated fine-grained materials, there is still a lack of understanding of the volumetric behavior of unsaturated granular materials. In this research, a model has been developed to predict the fundamental volumetric behavior of unsaturated granular materials through loading and wetting state paths. In this regard, a loading-wetting surface was developed in a space of void ratio-moisture ratio-net stress. A distinctive feature of the proposed model is the relative simplicity in obtaining the model parameters using conventional geotechnical testing equipment. Two types of recycled granular materials, commonly applied in unbound pavements were used, namely, recycled crushed brick (CB) and excavation waste rock (WR). The uniqueness of the developed surface was evaluated by employing a number of loading and wetting state paths. The results indicate that the developed surface is unique in its loading state paths; however, it only shows uniqueness in its wetting state paths for stress levels greater than 2000 kPa. The proposed model seeks to introduce the application of the unsaturated soil mechanics theory, for predicting the behavior of granular materials in the field, by providing a practical and cost-effective methodology.     

Performance of the bearing reinforcement earth wall as a retaining structure in the Mae Moh mine,Thailand

In this research, a Bearing Reinforcement Earth (BRE) wall with a residual clay stone backfill was successfully implemented as an alternative truck ramp support for an on-site crusher plant in the Mae Moh mine, Thailand. The performance of the BRE wall during and after the end of construction as well as during the service state was evaluated in terms of, settlement, bearing stress, lateral movement, lateral earth pressure and tension force in the reinforcements. Bearing reinforcement is a cost-effective inextensible earth reinforcement, which is composed of a longitudinal member and transverse members. The maximum settlement at the end of construction (20 days) was about 5 mm. The installation of the truck ramp (10 days after the end of construction) resulted in an immediate settlement of about 2 mm. The final settlement due to the backfill, truck ramp and truck load after 270 days was found to be uniform due to the contribution of bearing reinforcement and was approximately 25 mm. The bearing stress which was uniformly distributed was found to increase rapidly with construction time, which was in agreement with the relatively uniform settlements. The lateral wall movement at the front and lateral sides at the end of construction was very small with the maximum movement (at the top of the wall) found to be less than 10 mm. As such, the ratio of lateral movement to height (δ/H) was found to be approximately 0.12%, which was lower than the allowable value of 0.4%. With this low δ/H and the insignificant change in the measured settlement and lateral movement during service, the BRE wall was considered to have a very high stability. The coefficients of lateral earth pressure, K and depth relationship were proposed based on the analysis of measured maximum tensile force in the reinforcements. The maximum tension plane of the BRE wall could be represented by the coherent gravity hypothesis. Using the proposed K and maximum tension plane, the internal stability of the BRE wall was furthermore examined. A proposed method of designing the BRE wall with claystone backfill was also proposed.     

Numerical study of heat and moisture transport through concrete at elevated temperatures

This research article focuses on numerical investigation of heat and moisture transport through concrete exposed to high temperatures such as fire. The conservation equations for moisture and energy transport through concrete have been represented in terms of temperature, pore pressure and vapor content as field variables. As the resulting governing equations are coupled and non-linear, the equations were solved numerically using Galerkin’s weighted residual finite element method and an iterative solution technique. After validating the model, a detailed simulation study has been carried out to understand the role of gradients of temperature, pore pressure and vapor content on heat and moisture transport through concrete exposed to ISO 834 fire curve. Results obtained at the end of 30 minutes exposure of concrete show that the temperature gradients become very steep after 12 minutes of exposure of concrete, which in turn results in increased vapor generation and 93% of vapor generation is completed at the end of 20 minutes. Due to steep temperature gradient along the length of concrete, condensation of vapor takes place which is followed by blockage of pores giving rise to sudden peak pore pressure rise and 97% of peak pore pressure is attained at the end of 18 minutes itself. It is observed that for the initial 18 minutes, the peak pore pressure front and peak vapor content front follow the same path and after 18 minutes the peak vapor content front moves slightly ahead of the peak pore pressure front.     

Studies on long-term storage stability of biodiesel (B100) and its blend (B20) using Box-Behnken response surface method

The gradual depletion of fossil fuels has greatly enhanced the necessity to look for alternative fuels for automobile engines. In response to this, biodiesel is being considered as a promising and potential alternative substitute to conventional petroleum diesel. However, long-term storage stability of biodiesel is poorer compared to conventional petroleum diesel. The aim of the project work is to study the long-term storage stability of biodiesel (B100) and its blend (B20) prepared from used frying oil in different conditions of storage. In this work, the effect of antioxidants and temperature on long storage stability of biodiesel obtained from with respect to storage period is analysed using response surface methodology (RSM). The long storage of biodiesel obtained from used frying oils were optimised by varying parameters such as antioxidant concentration, storage period by Box-Behnken RSM. The properties such as the acid value and the viscosity of biodiesel were initially measured. The results of the investigation showed that the addition of sufficient concentration of antioxidant (pyrogallol) significantly maintains the acid value and viscosity of biodiesel and helps to store for a longer storage period at the given storage temperature.     

Regiospecific analysis of conifer seed triacylglycerols by gas-liquid chromatography with particular emphasis on Δ5-olefinic acids

Dibutyroyl derivatives of monoacylglycerols (DBMAG) from conifer seed oil triacylglycerols (TAG) were prepared by partial deacylation of TAG with ethylmagnesium bromide followed by diesterification with n-butyryl chloride. The resulting mixtures were analyzed by gas-liquid chromatography (GCL) with 65% phenylmethyl silicon open tubular fused-silica capillary column operated under optimal conditions and separated according to both their fatty acid structures and their regiospecific distribution. Seed oils of 18 species from 5 conifer families (Pinaceae, Taxaceae, Cupressaceae, Cephalotaxaceae, and Podocarpaceae) were analyzed. The chromatograms showed a satisfactory resolution of DBMAG containing palmitic (16∶0) stearic (18∶0), taxoleic (cis-5, cis-9 18∶2), oleic (cis-9 18∶1), cis-vaccenic (cis-11 18∶1), pinolenic (cis-5, cis-9, cis-12 18∶3), linoleic (cis-9, cis-12 18∶2), α-linolenic (cis-9 cis-12, cis-15 18∶3), and an almost baseline resolution of DBMAG containing gondoic (cis-11 20∶1), cis-5, cis-11 20∶2, sciadonic (cis-5, cis-11, cis-14 20∶3), dihomolinoleic (cis-11 cis-14 20∶2), juniperonic (cis-5, cis-11, cis-14, cis-17 20∶4), and dihomo-α-linolenic (cis-11, cis-14, cis-17 20∶3) acids. We have observed that results for Pinus pinaster and P. koraiensis seed oils obtained with this new simple method compared favorably with literature data established with other usual regiospecific analytical techniques. Δ5-Olefinic acids are esterified mainly at the external positions of the glycerol backbone in all cases, in agreement with data obtained by other methodologies allowing validation of the GLC regiospecific method. To date, 45 gymnosperm species (mostly Coniferophytes) from 21 genera belonging to 9 families have been analyzed, all of them showing a definite enrichment of Δ5-olefinic acids in the external positions of TAG. These fatty acids (FA), with one exception only, represent between-2 and 8% of FA esterified to the internal positions. For some species, i.e., P. koraiensis and P. pinaster, this asymmetrical distribution was established by at least three analytical procedures and confirmed by stereospecific analysis of their seed TAG.     

Long-term Sector-wise Electrical Energy Forecasting Using Artificial Neural Network and Biogeography-based Optimization

This article presents a hybrid model involving artificial neural networks and biogeography-based optimization for long-term forecasting of India's sector-wise electrical energy demand. It involves socio-economic indicators, such as population and per capita gross domestic product, and uses two artificial neural networks, which are trained through a biogeography-based optimization algorithm with a goal of perfect mapping of the input–output data in the non-linear space through obtaining the global best weight parameters. The biogeography-based optimization based training of the artificial neural network improves the forecasting accuracy and avoids trapping in local optima besides enhancing the convergence to the lowest mean squared error at the minimum number of iterations than existing approaches. The model requires an input and the year of the forecast and predicts the sector-wise energy demand. Forecasts up to the year 2025 are compared with those of the regression model, the artificial neural network model trained by back-propagation, and the artificial neural network model trained by harmony search algorithm to exhibit its effectiveness.     

Minocycline Loaded Hybrid Composites Nanoparticles for Mesenchymal Stem Cells Differentiation into Osteogenesis

Bone transplants are used to treat fractures and increase new tissue development in bone tissue engineering. Grafting of massive implantations showing slow curing rate and results in cell death for poor vascularization. The potentials of biocomposite scaffolds to mimic extracellular matrix (ECM) and including new biomaterials could produce a better substitute for new bone tissue formation. A purpose of this study is to analyze polycaprolactone/silk fibroin/hyaluronic acid/minocycline hydrochloride (PCL/SF/HA/MH) nanoparticles initiate human mesenchymal stem cells (MSCs) proliferation and differentiation into osteogenesis. Electrospraying technique was used to develop PCL, PCL/SF, PCL/SF/HA and PCL/SF/HA/MH hybrid biocomposite nanoparticles and characterization was analyzed by field emission scanning electron microscope (FESEM), contact angle and Fourier transform infrared spectroscopy (FT-IR). The obtained results proved that the particle diameter and water contact angle obtained around 0.54 ± 0.12 to 3.2 ± 0.18 µm and 43.93 ± 10.8° to 133.1 ± 12.4° respectively. The cell proliferation and cell-nanoparticle interactions analyzed using (3-(4,5-dimethyl thiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium inner salt) MTS assay (Promega, Madison, WI, USA), FESEM for cell morphology and 5-Chloromethylfluorescein diacetate (CMFDA) dye for imaging live cells. Osteogenic differentiation was proved by expression of osteocalcin, alkaline phosphatase activity (ALP) and mineralization was confirmed by using alizarin red (ARS). The quantity of cells was considerably increased in PCL/SF/HA/MH nanoparticles when compare to all other biocomposite nanoparticles and the cell interaction was observed more on PCL/SF/HA/MH nanoparticles. The electrosprayed PCL/SF/HA/MH biocomposite nanoparticle significantly initiated increased cell proliferation, osteogenic differentiation and mineralization, which provide huge potential for bone tissue engineering.