Copper substituted nickel ferrite nanoparticles anchored onto the graphene sheets as electrode materials for supercapacitors fabrication

Nickel ferrites with high theoretical capacitance value as compared to the other metal oxides have been applied as electrode material for energy storage devices i.e. batteries and supercapacitors. High tendency towards aggregation and less specific surface area make the metal oxides poor candidate for electrochemical applications. Therefore, the improvements in the electrochemical properties of nickel ferrites (NiFe₂O₄) are required. Here, we report the synthesis of graphene nano-sheets decorated with spherical copper substituted nickel ferrite nanoparticles for supercapacitors electrode fabrication. The copper substituted and unsubstituted NiFe₂O₄ nanoparticles were prepared via wet chemical co-precipitation route. Reduced graphene oxide (rGO) was prepared via well-known Hummer's method. After structural characterization of both ferrite (Ni_1-xCu_xFe₂O₄) nanoparticles and rGO, the ferrite particles were decorated onto the graphene sheets to obtain Ni_1-xCu_xFe₂O₄@rGO nanocomposites. The confirmation of preparation of these nanocomposites was confirmed by scanning electron microscopy (SEM). The electrochemical measurements of nanoparticles and their nanocomposites (Ni_0.9Cu_0.1Fe₂O₄@rGO) confirmed that the nanocomposites due to highly conductive nature and relatively high surface area showed better capacitive behavior as compared to bare nanoparticles. This enhanced electrochemical energy storage properties of nanocomposites were attributed to the graphene and also supported by electrical (I-V) measurements. The cyclic stability experiments results showed ~65% capacitance retention after 1000 cycles. However this retention was enhanced from 65% to 75% for the copper substituted nanoparticles (Ni_0.9Cu_0.1Fe₂O₄) and 65–85% for graphene based composites. All this data suggest that these nanoparticles and their composites can be utilized for supercapacitors electrodes fabrication.     

Fabrication of different conductive matrix supported binary metal oxides for supercapacitors applications

Here, we have fabricated the spinel binary-metal oxide (FeCo₂O₄) via a solvent-free and cost-effective approach. The nanocomposites of the as-fabricated binary-metal spinel oxide have been prepared with three different conductive-matrices, namely r-GO, CNTs, and PANI, via ultra-sonication approach. The spinel phase and surface functionalities of the fabricated FeCo₂O₄ sample have been confirmed via XRD and FT-IR analyses, respectively. The morphological-structure and elemental composition of the fabricated samples have been probed via FESEM and EDX results. The role of added conductive-matrices in the improvement of the electrical conductivities of the fabricated nanocomposites has been investigated via I–V experiments. The electrochemical experiments, conducted in half-cell configuration, showed that FeCo₂O₄/PANI nanocomposite exhibited the highest specific capacitance (658.9 Fg^-1) than that of the remaining two nanocomposites. Furthermore, FeCo₂O₄/PANI nanocomposite exhibited excellent cyclic stability as it lost just 8.3% of its initial specific capacitance even after 3000 cyclic tests. The superior capacitive-activity of the FeCo₂O₄/PANI nanocomposite is accredited to its high conductivity, large surface area, and synergy effects between the pseudocapacitance derived from the PANI and FeCo₂O₄ nanostructure. The electrochemical and electrical measurements suggested that FeCo₂O₄/PANI nanostructure is an emerging contender for energy storage applications.     

A hybrid knowledge and ensemble classification approach for prediction of venous thromboembolism

Clinical narratives such as progress summaries, lab reports, surgical reports, and other narrative texts contain key biomarkers about a patient's health. Evidence-based preventive medicine needs accurate semantic and sentiment analysis to extract and classify medical features as the input to appropriate machine learning classifiers. However, the traditional approach of using single classifiers is limited by the need for dimensionality reduction techniques, statistical feature correlation, a faster learning rate, and the lack of consideration of the semantic relations among features. Hence, extracting semantic and sentiment-based features from clinical text and combining multiple classifiers to create an ensemble intelligent system overcomes many limitations and provides a more robust prediction outcome. The selection of an appropriate approach and its interparameter dependency becomes key for the success of the ensemble method. This paper proposes a hybrid knowledge and ensemble learning framework for prediction of venous thromboembolism (VTE) diagnosis consisting of the following components: a VTE ontology, semantic extraction and sentiment assessment of risk factor framework, and an ensemble classifier. Therefore, a component-based analysis approach was adopted for evaluation using a data set of 250 clinical narratives where knowledge and ensemble achieved the following results with and without semantic extraction and sentiment assessment of risk factor, respectively: a precision of 81.8% and 62.9%, a recall of 81.8% and 57.6%, an F measure of 81.8% and 53.8%, and a receiving operating characteristic of 80.1% and 58.5% in identifying cases of VTE.     

Surface and Interface Analyses of UHV Evaporated Nb/AlOx/Nb Tri-layers

We have prepared Nb thin films with e-beam evaporation under UHV conditions. Al thin films were deposited by resistive heating in the UHV chamber. The preparation of these films and the tri-layers of Nb/AlOx/Nb were intended for their use in Josephson junctions. The surface studies of these films were undertaken by using scanning electron microscope and atomic force microscope in the non-contact mode, whilst the interface analysis was carried out by depth profiling using scanning Auger microprobe. These studies have revealed that Nb films grown on AlOx are smoother than the ones grown on Si. Further, it is seen that Al diffuses into Nb on both sides and that the interface is very broad. This intermixing of various materials results in the failure of the tri-layers when subjected to application in SQUIDs.     

Healthcare knowledge sharing among a community of specialized physicians

Healthcare organizations strive to make the best use of their organizational knowledge. The collective know-hows of the medical workers directly affect the quality of the delivered healthcare services. This study addresses the healthcare knowledge-sharing among a community of specialized physicians. An extensive study of the literature on knowledge-sharing in industries generally and healthcare organizations specifically were presented. Six focal elements were detected in previous attempts to address the knowledge-sharing status in healthcare organizations. Additionally, three previous models for healthcare knowledge management were analyzed. The studied literature along with the three studied models helped in constructing the framework and suggesting a suitable research methodology for primary data collection. Qualitative approach of in-depth interview technique was used for interviewing eight specialized physicians. The data collected from the interviewees were then analyzed and produced explanatory themes and codes. These themes are physicians’ acquisition of medical knowledge, staff participating in the knowledge sharing, knowledge-sharing culture, ICT-based knowledge sharing and top management involvement. The findings resulted in recognizing four considerations which ought to be taken into account for successful knowledge-sharing activities and learning initiatives in the healthcare organization. Conclusions and recommendations for future studies were presented based on the implications of this research study.     

Functional finishing and coloration of textiles with nanomaterials

Global demand for functional textiles is continually increasing for both conventional as well as advanced technical applications. Nanomaterials have the potential to transform the textile industry by imparting multifunctional properties such as physical, chemical and biological self‐cleaning, ultraviolet (UV) protection, wrinkle resistance and coloration to textiles without compromising the inherent characteristics of the substrate. This review highlights some of the major applications of nanomaterials to textile substrates to obtain different functional properties. Possible side effects of the nanomaterials on textiles are also reviewed, along with potential hazards to humans and the environment.     

The transformation of the inherited historical urban and architectural characteristics of Al-Najaf's Old City and possible preservation insights

This paper focuses on the dramatic transformation of the inherited historical urban and architectural characteristics of the city of Al-Najaf in Iraq, seeking new ways of seeing the possibilities of preserving and revitalizing the historical center of the city.In addition to being one of the most sacred centers for Shia Muslims, Al-Najaf has a rich cultural and architectural heritage. Its architectural characteristics and urban structure not only reflect the history of the city but also stand as evidence of the most important junctures in Islamic history: the martyrdom of Imam Ali ibn Abi Talib, who is a central Islamic spiritual personality and the second most important figure after the Prophet Muhammad. Since its establishment in 750 AD, the formation of Al-Najaf has never separated from its sociopolitical context and Islamic principles, particularly Shia Muslims’ beliefs.Today, the city is a destination for more than million Shia Muslim pilgrims each year, and the number is rapidly increasing. However, as the city continues to develop, its architecture and unique urban structure transform dramatically. The cultural and architectural heritage of the city is seriously threatened. Several factors played a crucial role in the formation and the transformation of the city's specific architectural and urban structures. The most influential factors were mainly related to religion, environment, and politics. This paper introduces the main forces behind the transformation of the deep organizational structures of the architecture and urban fabric in Al-Najaf. The question of whether it is still possible to protect and preserve the remaining parts and revitalize the Old City center is also examined. The goal is to identify the major preservation issues and provide possible insights based on successful preservation experiences that address similar issues in different contexts.     

Enhanced Cr(vi) removal using iron nanoparticle decorated graphene

Nanoscale iron particles decorated graphene sheets synthesized via sodium borohydride reduction of graphene oxide, showed enhanced magnetic property, surface area and Cr(vi) adsorption capacity compared to bare iron nanoparticles.     

Modeling and Analysis of a Hydrogen Reformer for Fuel Cell Applications

Fuel cells that utilize hydrogen and oxygen to produce energy are promising power sources. However, there are operational difficulties in storing hydrogen. One way to alleviate this problem is to generate hydrogen in situ from a liquid fuel via steam reforming. In this paper, an ethanol reformer was modeled as a tubular non-isothermal, non-isobaric packed-bed reactor with an annular heat transfer jacket, operating at unsteady state. A suitable heat transfer jacket was designed that provides heat to the reformer by combustion of ethanol. The partial differential equations of the reformer model were solved numerically and model predictions of hydrogen generation were shown to be in good agreement with experimental data available in the literature for a laboratory-scale reformer. A commercial-scale reformer was designed using this high-fidelity model that can produce sufficient hydrogen to generate up to 5 kW of power when used in conjunction with a Ballard Mark V fuel-cell stack. Experimental data from the dynamic power consumption in a 3-bedroom house were used to validate the size of the reformer as well as a back-up battery that supplies power when the reformer is unable to meet the power demand.