Ultralow Pt loading on CVD graphene for acid electrolytes and PEM fuel cells

Continuous-phase, porous graphene was produced by CVD process and tested for suitability as catalyst and catalyst support for polymer electrolyte membrane (PEM) fuel cells. N-doping of CVD graphene was carried by NH₃ gas flown over graphene for a given time. Ultralow Pt was sputter deposited onto porous, continuous phase N-doped graphene. Oxygen reduction reaction (ORR) activity by Rotating Disc Electrode (RDE) in 0,1 M HClO₄ electrolyte and PEM fuel cell performance were measured. N-doping and thicker Pt sputtering increases reduction current in RDE measurements. Sputter deposition of 1 nm and 10 nm Pt on CVD graphene (2.1 and 21.45 μgPt/cm² loading) has shown orders of magnitude increase in current compare to only-graphene samples. In fuel cell testing, sputter deposited Pt layer of 10 nm has provided 2.5 A/mgPt at 0.5 V polarization while 1 nm samples shows 15 A/mgPt performance at the same voltage.     

Investigating the relationship between workplace conflict and employee agility: The role of enterprise social media

The current research aims to investigate the relationship between workplace conflict and employee agility in firms that adopt enterprise social media (ESM). Using the information processing perspective, this study proposes a model for examining how task conflict and relationship conflict relate to employee agility and how ESM moderates these relationships. The regression analysis results are based on 161 respondents who adopted ESM in the workplace, and are used to examine the impact of task and relationship conflict on employee agility. The results show that relationship conflict has a U-shaped curvilinear relationship with employee agility. Conversely, the association between task conflict and employee agility is has an inverted U-shaped relationship. Moreover, the link between task conflict and employee agility is moderated by ESM usage, such that the curvilinear relationship is weakened by ESM usage. This study contributes to extant ESM literature by investigating workplace conflict and its role in developing employee agility in ESM environments. The findings indicate that managers should implement appropriate strategies to maintain a certain level of conflict in order to facilitate and achieve employee agility.     

3D printing for soft robotics – a review

Soft robots have received an increasing attention due to their advantages of high flexibility and safety for human operators but the fabrication is a challenge. Recently, 3D printing has been used as a key technology to fabricate soft robots because of high quality and printing multiple materials at the same time. Functional soft materials are particularly well suited for soft robotics due to a wide range of stimulants and sensitive demonstration of large deformations, high motion complexities and varied multi-functionalities. This review comprises a detailed survey of 3D printing in soft robotics. The development of key 3D printing technologies and new materials along with composites for soft robotic applications is investigated. A brief summary of 3D-printed soft devices suitable for medical to industrial applications is also included. The growing research on both 3D printing and soft robotics needs a summary of the major reported studies and the authors believe that this review article serves the purpose.     

Hydromagnetic double-diffusive convection in a rectangular enclosure with opposing temperature and concentration gradients

The finite-difference method is used to predict numerically the characteristics of hydromagnetic double-diffusive convective flow of a binary gas mixture in a rectangular enclosure with the upper and lower walls being insulated. Constant temperatures and concentrations are imposed along the left and right walls of the enclosure and a uniform magnetic field is applied in the x-direction. Consistent with what is reported by previous investigators, an oscillation in the flow is observed in the absence of the magnetic field for a specific range of buoyancy ratio values where the Prandtl number Pr=1, the Lewis number Le=2, the thermal Rayleigh number Ra_T=10⁵, and the aspect ratio A=2 for the enclosure. In the presence of the magnetic field, however, no oscillatory behavior is observed. Numerical results are reported for the effect of the heat generation or absorption coefficient and the Hartmann number on the contours of streamline, temperature, concentration and density. In addition, results for the average Nusselt and Sherwood numbers are presented and discussed for various parametric conditions. In this study, the thermal and compositional buoyancy forces are assumed to be opposite.     

Acid modified local clay beads as effective low-cost adsorbent for dynamic adsorption of methylene blue

Locally sourced clay was harnessed to study its adsorptive potential of methylene blue (MB) in wastewater streams. The clay was modified with sulfuric acid and aluminum hydroxide. The raw and modified freeze dried clay bead RHC and MHC were subjected to batch and batch/fixed-bed adsorption studies, respectively. Elemental analysis, morphological structures were determined, and surface area of 19.3 (RHC) and 101.2 (MHC) m²/g were obtained. Langmuir, Freundlich and Redlich–Peterson isotherms models were analyzed and the modification increased adsorption capacity from 58.02 to 223.19 mg/g at 30 °C. The MB adsorption on RHC/MHC was spontaneous, exothermic and obeyed pseudo-second-order model.     

Light microscopy and scanning electron microscopy: Implications for authentication of misidentified herbal drugs

Plant‐based drugs have reached remarkable acceptability as therapeutic remedy for various diseases due to the adverse effects of contemporary medicines. This increasing popularity of herbal drugs leads to a growing herbal market for the development of plant‐based drugs, nutraceuticals, pharmaceuticals and cosmeceuticals. Herbal drug adulteration is a complex problem which currently has undeniable consequences on health and nutrition. Ambiguities in nomenclature, misidentification and resemblance of colour and texture of the crude herbal drugs are the major causes of adulteration. Three different species commercially marketed under the same trade name Halion are Lepidium apetalum, Asparagus officinalis, and Lepidium didymum. The genuine source of Halion is Lepidium apetalum, which is authenticated by using basic and advanced taxonomic techniques. Morphology, anatomy and palynology of the misidentified sources were done using light and scanning electron microscopic techniques for authentication. This study may help to set microscopic techniques as a tool to achieve quality and standardization of the genuine source of the herbal drug. Phytochemical analysis and biological screening is needed for the further establishment of authenticity and quality of herbal drugs.     

Mapping riparian habitat using a combination ofremote-sensing techniques

Light detection and ranging (lidar) and object-oriented classification (OOC) can be used to overcome the shortcomings of the traditional pixel-based classification (PBC) of coarse spatial resolution data, such as Landsat data, for habitat mapping in riparian zones. The purposes of this study were to investigate methods to classify multispectral data and lidar for riparian habitat mapping, and to identify major habitat components for two target species. The mapping of riparian habitat based on OOC and Decision Tree Classification (DTC) was carried out by merging vertical data from lidar and spectral data of high-resolution imagery. Our results showed an overall classification accuracy of 88.2%. In particular, small and continuous habitat types, such as short and tall grasses, rock outcrop and gravel, and riffles, improved the classification accuracy compared with the pixel-based methods. The habitat patches and paths for each target species were identified by incorporating the point data from the field survey and the outcomes of image classification. Our study demonstrated that the proposed methodology can be successfully used for the identification and restoration of fragmented riparian habitats, and can offer an opportunity to obtain high classification accuracies for microhabitat components in dynamic riverine areas.