Low-Temperature Water Gas Shift Reaction on Combustion Synthesized Ce1−x Pt x O2−δ Catalyst

Catalytic activity of Pt²⁺ ion substituted CeO₂ synthesized by solution combustion method was tested for low-temperature water gas shift reaction in H₂ rich steam reformate. XPS studies show that Pt is dispersed as ions and there is no change in Pt oxidation state after the reaction. CO conversion is found to be maximum at 200 °C over Ce_1?x Pt _x O_2?δ catalysts without any methanation. The values of rate are 1.86 and 4.66 μmol/g/s at 125 and 150°C respectively with a dry gas flow rate of 6 Lh^?1 over 2% Pt/CeO₂.     

Valvetrain Friction Reduction through Thin Film Coatings and Polishing

In a direct-acting mechanical bucket tappet–type valvetrain, the cam and tappet contact is responsible for about 85% of the total valvetrain frictional losses. Because this contact operates primarily in a mixed lubrication regime, it offers an opportunity for friction reduction through surface engineering. The friction reduction potential of thin Mn-phosphate coating, diamond-like carbon coating, and polishing on the bucket surface was explored using a motored valvetrain rig equipped with 3.5L V6 engine head. The durability of tappets and cam lobes was also evaluated using a different motored valvetrain rig consisting of a single lobe and a single tappet. The polished buckets demonstrated substantial friction benefit over current production buckets at all speeds investigated. The diamond-like carbon coated buckets did not show any additional friction reduction benefit. The wear data demonstrated much less wear with polished buckets and also for cam lobes when in contact with polished buckets compared to current production buckets and cam lobes. The composition of antiwear surface films on polished buckets was found to be similar to that on current production buckets.     

Bubble evolution and necking at a submerged orifice for the complete range of orifice tilt

Bubble formation at an inclined orifice has been studied numerically using coupled‐diffused interface‐smoothed particle hydrodynamics. The simulation covers the entire range of orifice inclination, starting from upward facing (0^°) to downward facing (180^°) orientation for a moderate air flow (30 cm³/s). Bubble at the orifice mouth becomes asymmetric as the plate gets tilted. The asymmetry maximizes at vertical orientation but with downward facing orifices symmetry restores. The local hydrodynamic structure reveals that the internal circulation cells in bubble become stronger as the inclination increases making the growing bubble asymmetric. Interestingly, bubble volume for downward facing orifice is 4.75 times higher than the bubble released at upward facing orifice. Observations from the present simulations suggest that bubble frequency and shape can be controlled by allowing appropriate inclination in the orifice mouth. © 2012 American Institute of Chemical Engineers AIChE J, 59: 630–642, 2013     

Biological and chemical factors affecting the valuation of North East Indian plains teas. III. Statistical Evaluation of the Biochemical Constituents and their Effects on Colour,Brightness and Strength of Black Teas

Regardless of tasters and methods of manufacture five biochemical factors, total oxygen uptake of unprocessed tea shoots and theaflavins (TF), thearubigins (TR), (?)-epigallocatechin gallate (EGCE) and theogallin (TG), of black tea are the main contributing factors of colour of North East India plains tea. Similarly, three constituents, TF, TR and (?)-epicatechin gallate (ECG) of black tea, are main the factors for brightness. Four factors, total oxygen uptake and ECG of unprocessed tea shoots and TF and moisture of black tea are the main contributing factors of strength of North East Indian plains tea.     

Sequential interval estimation via replicated piecewise stopping times and accelerated stopping times in a class of two-parameter exponential family of distributions

We reconsider the problem of constructing interval estimate of fixed proportional accuracy as introduced in Bose and Boukai (1993b). We discuss two approaches to make their fully sequential procedure operationally more attractive. First, we propose to implement their sequential procedure in smaller pieces along the lines of Mukhopadhyay and Sen (1993). Second, we perform purely sequential sampling part of the way, followed by appropriate batch sampling. In either case we provide the second-order expansion of the coverage probability and these compare well with that of the full sequential procedure. Along the way we also relax some of the technical restrictions of Bose and Boukai (1993b).     

An image retrieval scheme based on block level hybrid dct-svd fused features

Multimedia Tools and Applications - In this paper, an image retrieval scheme has been proposed based on block level hybrid features. The block level salient feature are extracted in two parts:...     

Investigation of droplet coalescence propelled by dielectrophoresis

We propose dielectrophoretic force driven coalescence of droplets having equal or nonequal sizes with an electrode base actuation system over a solid surface. Coupled electrohydrodynamic conservation equations are solved to simulate the phenomenon based on finite volume scheme. Volume of fluid technique is used to capture the interface. Electric potential and dissimilarity index are varied to comprehend the coalescence dynamics. The interplay between the capillary and electrostatic influences during the coalescence is analyzed by tracking the dimension of the liquid connection formed at the onset of fusion. Efforts have been made to characterize the liquid bridge formation as a function of inertia normalized time scale. The capillary force showed higher dominance in the initial period of agglomeration. The electrostatic influence can be perceived at the latter stages of the growth of liquid connection. Directional predilection in the flow field is observed during the coalescence of dissimilar droplets. © 2018 American Institute of Chemical Engineers AIChE J, 65: 829–839, 2019