Effect of anisotropic electrical resistivity of gas diffusion layers (GDLs) on current density and temperature distribution in a Polymer Electrolyte Membrane (PEM) fuel cell

A two-dimensional two-phase model is used to analyze the effects of anisotropic electrical resistivity on current density and temperature distribution in a PEM fuel cell. It is observed that a higher in-plane electrical resistivity of the gas diffusion layer (GDL) adversely affects the current density in the region adjacent to the gas channel and generates slightly higher current densities in the region adjacent to the current collector. Also, in case of GDLs with high anisotropic thermal conductivity, the maximum and minimum temperatures in a cathode catalyst layer depend on the average current density and not the local current density.     

A Comprehensive Review on the Interaction of Milk Protein Concentrates with Plant-Based Polyphenolics

Functional properties and biological activities of plant-derived polyphenolic compounds have gained great interest due to their epidemiologically proven health benefits and diverse industrial applications in the food and pharmaceutical industry. Moreover, the food processing conditions and certain chemical reactions such as pigmentation, acylation, hydroxylation, and glycosylation can also cause alteration in the stability, antioxidant activity, and structural characteristics of the polyphenolic compounds. Since the (poly)phenols are highly reactive, to overcome these problems, the formulation of a complex of polyphenolic compounds with natural biopolymers is an effective approach. Besides, to increase the bioavailability and bioaccessibility of polyphenolic compounds, milk proteins such as whey protein concentrate, sodium caseinate, and milk protein concentrate act as natural vehicles, due to their specific structural and functional properties with high nutritional value. Therefore, milk proteins are suitable for the delivery of polyphenols to parts of the gastrointestinal tract. Therefore, this review reports on types of (poly)phenols, methods for the analysis of binding interactions between (poly)phenols–milk proteins, and structural changes that occur during the interaction.     

Occurrence and genetic diversity of ESBL producing Klebsiella species isolated from livestock and livestock products

Klebsiella species have been at the center of attention over the recent years due to its role in the evolution of antimicrobial resistance and is not only associated with nosocomial but also with food related infections worldwide. In this study, out of 336 samples of animal intestinal and foods of animal origin screened, 99 samples were found to harbor Klebsiella spp. Out of 99 isolates, 89 were Klebsiella pneumoniae and 10 were found to be Klebsiella oxytoca by mPCR. The isolates were subjected to antibiotic sensitivity test including ESBL detection by genotypic (PCR) and phenotypic (disc diffusion) methods. β-Lactamase genes were identified in 32 isolates of K. pneumoniae and an isolate of K. oxytoca, blaSHV being the predominant gene detected (31) followed by blaTEM, blaCTX-M1, and blaCTX-M9 (one each), whereas single K. oxytoca isolate harbored blaCTX-M2 gene. Genetic fingerprinting of β-lactamase producing K. pneumoniae using ERIC-PCR and REP-PCR differentiated all the 32 strains with discriminatory power of 1.     

Artificial intelligence-based correlation: Process side heat transfer coefficient for helical coils in stirred tank reactors

Stirred tank reactor systems often employ jackets/limpets, single/multiple internal coils for heat transfer. Internal coils are used for heat removal in the case of exothermic reaction systems. The desired heat transfer area can be accurately estimated based on the overall heat transfer coefficient (HTC) considering the process side, utility side, and wall conduction resistance. For estimation of process side HTC, a large number of empirical/semi-empirical correlations are available in the published literature. These correlations account for impeller Reynolds number, fluid Prandtl number, viscosity ratio, dimensionless geometric factors, and so forth. However, all the factors over the entire range of industrial operation do not get covered in a single study, hence the predictions may involve significant errors for industrial cases. The advanced artificial intelligence-based techniques can provide unified correlation based on the experimental data set extracted from various investigations and the predictions can be accurate and reliable. In the present work, three techniques random forests (RF), artificial neural networks with Bayesian optimization (ANN-BO), and support vector regression with grid search optimization (SVR-GS) have been used with a data set of 1297 points with R² values of 0.995, 0.972, 0.990 on the training data set and 0.962, 0.945, 0.905 respectively on the testing data set. Furthermore, the statistical measures show that RF provides a better fit as compared with other AI models, so RF is used for parametric sensitivity analysis. The permutation feature importance shows that the agitation speed, impeller dimensions, and positioning has a significant impact on the HTC.     

Cutting tool performance analysis of P/M alloy steel under turning of copper material

Journal of Mechanical Science and Technology - Automation in machining processes requires high strength new cutting tool to co-up with high speed, feed and high-temperature working conditions. The...     

Traffic Aware Congestion Control Priority Based Efficient Adaptive Multipath Routing in Wired Networks with New Queuing Technique

Wireless Personal Communications - This paper proposes a novel technique for data transmission from source to destination by using adaptive multipath routing with route adaptability. In this...     

Non-Newtonian power-law flow and heat transfer across a pair of side-by-side circular cylinders

Flow and heat transfer of non-Newtonian power-law fluids across a pair of identical circular cylinders in side-by-side arrangement are investigated numerically by solving the continuity, momentum and energy equations along with the appropriate boundary conditions. The numerical calculations are performed in an unconfined computational domain for the following range of physical parameters: Reynolds number, Re = 1–40 and power-law index, n = 0.4–1.8 (covering shear-thinning, n < 1; Newtonian, n = 1 and shear-thickening, n > 1 behaviors) for gap ratio, T/D = 1.5–4.0 at a constant Prandtl number of 50. The global characteristics such as drag coefficients and average Nusselt number, etc. are calculated and the representative streamline and isotherm contours are presented for the above range of conditions. It has been found that the individual and overall drag coefficients decrease and the average Nusselt number increases with Reynolds number for all T/D and n considered here. The heat transfer is found higher in shear-thinning fluids than Newtonian fluids and followed by shear-thickening fluids for 1.5 ? T/D ? 4.0 and 1 ? Re ? 40.     

Flow and heat transfer in serpentine channels

Serpentine channels are often used in microchannel reactors and heat exchangers. These channels offer better mixing, higher heat and mass‐transfer coefficients than straight channels. In the present work, flow and heat transfer experiments were carried out with a serpentine channel plate comprising of 10 units (single unit dimensions: 1 × 1.5 mm² in cross section, length 46.28 mm, D_h 1.2 mm) in series. Pressure drop and heat‐transfer coefficients were experimentally measured. Flow and heat transfer in the experimental set‐up were simulated using computational fluid dynamics (CFD) models to understand the mechanisms responsible for performance enhancement. The CFD methodology, thus, developed was applied to understand the effect of various geometrical parameters on heat transfer enhancement. A criterion was defined for evaluation of heat transfer performance (heat transfer per unit pumping power), thus, ensuring due considerations to required pumping power. The effect of geometrical parameters and the corresponding mechanisms contributing for enhancement are discussed briefly. Based on the results, a design map comprising different serpentine channels showing heat transfer enhancement with pumping power was developed for Reynolds number of 200 which will be useful for further work on flow and heat transfer in serpentine channels. © 2012 American Institute of Chemical Engineers AIChE J, 59: 1814–1827, 2013