Design of fuel cell systems laboratory for hydrogen,carbon monoxide and hydrocarbon safety

As research and development efforts in the area of fuel cells and hydrogen based energy accelerate, a large number of accidents have occurred in research laboratories. In this context, a design methodology for a simple, scaleable, modular and human-independent system for hydrogen, carbon monoxide and hydrocarbon safety in research laboratories is valuable. We have designed, developed and operationalized such a system in a pre-existing generic laboratory space. In this paper, we provide details of the mechanical, electrical and control aspects of this laboratory. We use CFD analysis to design a ventilation system, and to locate gas detectors for optimum detection time. The gas detectors, actuators, a real-time controller and other electrical components are part of a safety monitoring system that continuously gathers information, processes this information and takes appropriate action to safeguard personnel and equipment in real time. This fully operational safety laboratory is now a University-level research hub for all fuel cell (and other energy related) research activities, and is also one of a kind in the region. We also expect that the experience gained in this endeavor will be useful to other researchers in building a safe workplace.     

DeepFakE: improving fake news detection using tensor decomposition-based deep neural network

The Journal of Supercomputing - Social media platforms have simplified the sharing of information, which includes news as well, as compared to traditional ways. The ease of access and sharing the...     

Minimum variance embedded auto-associative kernel extreme learning machine for one-class classification

Neural Computing and Applications - One-class classification (OCC) needs samples from only a single class to train the classifier. Recently, an auto-associative kernel extreme learning machine was...     

Aqua-mediated in situ synthesis of highly potent phosphorous functionalized flame retardant for cotton fabric

Flame retardancy in various materials is becoming an increasingly important performance feature. In the textile industries, fire-related problems have become an important concern over the decade. Herein, the polyvinyl alcohol (PVA) and graphene-supported material were functionalized with trimethyl phosphate (TMP) for the synthesis of flame retardant (FR) composite material [graphene polymer functionalized trimethyl phosphate (GPTMP)] in the aqueous medium, which improves the stability of cotton fabric against flame. Graphene and PVA fabricated with phosphorus functional groups make the fabric more comfortable against fire and help to avoid further spreading of fire. The composite-coated fabric sustains for a long time on continuous flame with maintaining its initial shape and size. The GPTMP-coated fabric shows flame retardancy for up to 540 s on constant flame exposure, whereas control samples such as PVA-, graphene oxide-, and TMP-coated fabrics resist for up to 15, 20, and 14 s, respectively. The limiting oxygen index (LOI) and vertical flammability test (VFT) for synthesized composites were performed to confirm and support the flame retardancy property of GPTMP. The GPTMP shows the 35% LOI value and forms the char length of 2.6 cm during VFT. This work provides a simple and eco-friendly method to obtain novel GPTMP, which has a high potential as a FR for different fabrics, including cotton.     

Effect of Exposure Face Orientation and Tilt Angle on Immersion Corrosion Behavior of Dual-Phase and Mild Steels

The present study aims to investigate the effect of the exposure angle (0°, 30°, 45°, 60° and near 90°) and the number of exposed faces (skyward and downward surfaces) on the immersion corrosion behavior of a dual phase and a mild steel in freely aerated stagnant 3.5% NaCl solution for a period of 10 days. In one case, two surfaces are exposed simultaneously, whereas in other case, one of the surfaces is exposed, while other is lacquered. Analysis shows that the corrosion rate of the skyward surface is considerably high when both the surfaces are exposed. The corrosion rate of the downward surface is higher than that of the skyward sample, when one of the surfaces is exposed. Moreover, the corrosion rate gradually decreases from zero to near-90° orientation for all the cases. Though the effect of tilt angle and exposed face does not depend on steel varieties, the dual-phase steel has higher corrosion resistance than the mild steel. Relative oxygen content, microcell formation, gravity effect and reaction nature with depth are the plausible reasons for the observed variation of corrosion behavior.     

In Situ Synthesis and Characterization of Shape Memory Alloy Nitinol by Laser Direct Deposition

Nitinol is well known for its unique shape-memory and super-elastic properties along with its excellent biomechanical compatibility and corrosion resistance. In this study, a laser direct deposition technique was explored to synthesize high-quality, near-net-shape nitinol components directly from elemental nickel and titanium powders as opposed to using expensive prealloyed nitinol powder. The systematic characterization of samples was done using X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS). Transformation temperatures were obtained using differential scanning calorimetry (DSC). With an optimum ratio of nickel and titanium powder mixture, optimal laser parameters, and post-heat treatment, samples with homogeneous and nearly fully dense NiTi phase were synthesized with less unwanted secondary phases occupying less than 3.2 pct volume fraction. Furthermore, these results were compared with those obtained for samples deposited using prealloyed nitinol powder. This technique offers maximum flexibility and cost benefit in the manufacturability of near-net-shape nitinol components.     

Assessment of drilling-induced damage in CFRP under chilled air environment

Drilling holes in carbon fiber-reinforced polymer (CFRP) laminates are more prone to incur damage during machining. Surface damage could be considerably minimized through the adoption of cryogenic assisted machining. The economic and safety implications associated with cryogenic technology necessitate the exploration of alternate technologies. In this research work, the effects of cutting velocity (100, 125, and 150?m/min) and feed rate (0.03, 0.06, and 0.09?mm/rev) on thrust force, surface roughness, delamination, and acoustic emissions are studied during the drilling of CFRP laminates under chilled air environment and compared with dry drilling. The output parameters are found to be much influenced by feed rate than cutting velocity. Under high feed rate and cutting velocity, the delamination factor, surface roughness, and acoustic emissions are, respectively, reduced by 13.2, 10.5, and 7.4% for the drilling performed under chilled air environment over dry condition. About 9.9% increased thrust force is observed for chilled air-assisted drilling under the identical machining condition.     

Formulation and evaluation of floating tablet of H2-receptor antagonist

Context: Conventional sustained dosage form of ranitidine hydrochloride (HCl) does not prevent frequent administration due to its degradation in colonic media and limited absorption in the upper part of GIT.

Objectives: Ranitidine HCl floating tablet was formulated with sublimation method to overcome the stated problem.

Methods: Compatibility study for screening potential excipients was carried out using Fourier transform infrared spectroscopy (FT-IR) and differential scanning chromatography (DSC). Selected excipients were further evaluated for optimizing the formulation. Preliminary screening of binder, polymer and sublimating material was based on hardness and drug release, drug release with release kinetics and floating lag time with total floatation time, respectively. Selected excipients were subjected to 3² factorial design with polymer and sublimating material as independent factors. Matrix tablets were obtained by using 16/32” flat-faced beveled edges punches followed by sublimation.

Results: FT-IR and DSC indicated no significant incompatibility with selected excipients. Klucel-LF, POLYOX WSR N 60?K and l-menthol were selected as binder, polymer and sublimating material, respectively, for factorial design batches after preliminary screening. From the factorial design batches, optimum concentration to release the drug within 12?h was found to be 420?mg of POLYOX and 40?mg of l-menthol. Stability studies indicated the formulation as stable.

Conclusion: Ranitidine HCl matrix floating tablets were formulated to release 90% of drug in stomach within 12?h. Hence, release of the drug could be sustained within narrow absorption site. Moreover, the dosage form was found to be floating within a fraction of second independent of the pH of media ensuring a robust formulation.     

Characterization of superhydrophobic materials using multiresonance acoustic shear wave sensors

Various superhydrophobic (SH) surfaces, with enhanced superhydrophobicity achieved by the use of nanoparticles, were characterized by a new acoustic sensing technique using multiresonance thickness-shear mode (MTSM) sensors. The MTSM sensors were capable of differentiating SH properties created by nano-scale surface features for film, exhibiting similar macroscopic contact angles.     

Effect of mechanical and electrical activation on the combustion synthesis of Al3Ti

Titanium aluminides have attracted immense interest as lightweight intermetallic compounds that possess good high-temperature mechanical and corrosion properties. In the present work, titanium aluminides (Al₃Ti) have been reactively processed from elemental powder using a combined mechanical and electrical activation approach. The effect of mechanical activation and electric current intensity on the ignition and phase development is discussed. Ignition was not possible when powders were milled for a short time, while prolonged milling resulted in mechanical activation that promoted a self-propagating-type reaction. The time to engulfment of the compact with the reaction wave was found to decrease with an increase in current intensity. A secondary reaction occurred at the higher current intensity, which in turn increased the product homogeneity.