Irradiation of large area Mylar membrane and characterization of nuclear track filter

Ion irradiation of Si⁸⁺ ion beam of 100 MeV was scattered by a gold foil on a Mylar membrane of 25 Μm thickness in the form of film roll (width, 12.5 cm and length, 400 cm) at the Nuclear Science Centre, New Delhi. The characterization of etched nuclear tracks was carried out by gas permeation measurements. The samples cut from the film roll of required size for permeability measurements were etched in a controlled manner in a constant temperature bath of 6N NaOH solution. The opening of the conical etched tracks was characterized by hydrogen gas permeation.     

Inhibition of sickle beta-chain (betaS)-dependent polymerization by nonhuman alpha-chains. A superinhibitory mouse-horse chimeric alpha-chain

Horse alpha-chain inhibits sickle beta-chain-dependent polymerization; however, its inhibitory potential is not as high as that of mouse alpha-chain. Horse alpha-(1-30) and alpha-(31-141) segments make, respectively, minor and major contributions to the inhibitory potential of horse alpha-chain. The sum of the inhibitory potential of the two segments does not account for the inhibitory potential of the full-length horse alpha-chain. Although the polymerization inhibitory potential of horse alpha-chain is lower than mouse alpha-chain, the inhibitory potential of horse alpha-(31-141) is comparable to that of mouse alpha-(31-141). When mouse alpha-(1-30) is stitched to horse alpha-(31-141), the product is a chimeric alpha-chain with an inhibitory potential greater than mouse alpha-chain. In contrast, the stitching of horse alpha-(1-30) with mouse alpha-(31-141) had no additional inhibitory potential. Molecular modeling studies of HbS containing the mouse-horse chimeric alpha-chain indicate altered side-chain interactions at the alpha1beta1 interface when compared with HbS. In addition, the AB/GH corner perturbations facilitate a different stereochemistry for the interaction of the epsilon-amino group of Lys-16(alpha) with the beta-carboxyl group of Asp-116(alpha), resulting in a decrease in the accessibility of the side chain of Lys-16(alpha) to the solvent. Based on molecular modeling, we speculate that these perturbations by themselves, or in synergy with the altered conformational aspects of the alpha1beta1 interactions, represent the molecular basis of the superinhibitory potential of the mouse-horse chimeric alpha-chains.     

Design Errors: Inefficiency or Carelessness of Designer?

Design defects are experienced in many projects; the difference is only in the extent of occurrence. This technical note discusses a design error case in a building project in Nepal, where the designer made the wrong assumptions in roof treatment work for waterproofing as well as for heat insulation purposes. From the investigation of the problem, it was found that the waterproofing polymer was not applied directly over concrete slab top. Use of heavy concrete block as a heat insulation material also helped to increase the leakage problem. The problem evoked loss of prestige for project officials, the design consortium, and the contractor.     

Transducin-alpha C-terminal peptide binding site consists of C-D and E-F loops of rhodopsin

The binding of heterotrimeric GTP-binding proteins (G-proteins) to serpentine receptors involves several independent contacts. We have deduced the points of interaction between mutant bovine rhodopsins and alphat-(340-350), a peptide corresponding to the C terminus of the alpha subunit (alphat) of bovine retinal G-protein, transducin. Direct binding of alphat-(340-350) to rhodopsin stabilizes the activated metarhodopsin II state (M II), consequently uncoupling the rhodopsin-transducin interaction. This peptide action requires two segments on the cytoplasmic domain of rhodopsin: the Tyr136-Val137-Val138-Val139 sequence on the C-D loop and the Glu247-Lys248-Glu249-Val250-Thr251 sequence on the E-F loop. We propose that a tertiary interaction of these two loop regions forms a pocket for binding the alphat C terminus of the transducin during light transduction in vivo. In most G-proteins, the C termini of alpha subunits are important for interaction with receptors, and, in several serpentine receptors, regions similar to those in rhodopsin are essential for G-protein activation, indicating that the interaction described here may be a generally applicable mode of G-protein binding in signal transduction.     

Multiperson interaction recognition in images: A body keypoint based feature image analysis

Most interaction recognition approaches have been limited to single‐person action classification in videos. However, for still images where motion information is not available, the task becomes more complex. Aiming to this point, we propose an approach for multiperson human interaction recognition in images with keypoint‐based feature image analysis. Proposed method is a three‐stage framework. In the first stage, we propose feature‐based neural network (FCNN) for action recognition trained with feature images. Feature images are body features, that is, effective distances between a set of body part pairs and angular relation between body part triplets, rearranged in 2D gray‐scale image to learn effective representation of complex actions. In the later stage, we propose a voting‐based method for direction encoding to anticipate probable motion in steady images. Finally, our multiperson interaction recognition algorithm identifies which human pairs are interacting with each other using an interaction parameter. We evaluate our approach on two real‐world data sets, that is, UT‐interaction and SBU kinect interaction. The empirical experiments show that results are better than the state‐of‐the‐art methods with recognition accuracy of 95.83% on UT‐I set 1, 92.5% on UT‐I set 2, and 94.28% on SBU clean data set.     

A novel microfluidic switch for pH control using Chitosan based hydrogels

We report a novel pH-sensitive hydrogel based micro-valve for metered flow that has applications in a laboratory made “Intelligent valving system”. The hydrogel solution was prepared through Chitosan and poly vinyl alcohol in acetic acid and crystallized using gluteraldehyde as the crosslinking agent in the form of thin wafers and it was found to be very sensitive to pH changes. The pore structure of hydrogel was investigated through Field Emission Scanning Electron Microscopy and thin wafers of the gel were physically placed inside PDMS microchannels. Flow metering in these channels was observed by controlled expansion of the hydrogel plug till complete valving was realized. This valving device was further precisely characterized with micro Particle Image Velocimetry using a solution containing fluorescent polymeric micro beads. The principle advantage of this hydrogel device is the smaller range of pH (varying between pH 3 and 7) over which the valving response is observed.     

Limits of compensation in a failed antenna array

In large antenna arrays, the possibility of occurrence of faults in some of the radiating elements cannot be precluded at all times. In such situations, the radiation pattern of the array gets distorted, mostly with an increase in sidelobe level and decrease in gain. Although it is not possible to restore the pattern fully by rearranging the excitations of the functioning elements, compensation methods have been reported in the literature for restoring one performance parameter of the array and making a trade‐off on some other parameter. In this article, we have made a study on the tolerance level of this compensation process. One part of the study deals with the thinning in the failed array, that is, to find a limit on the minimum number of functioning elements of the array that can restore the digital beamforming of the failed array. The second part of study deals with finding the maximum number of element failures that can be compensated. The study was carried out by optimizing the amplitude excitations of the failed array. Instead of classical optimization techniques, particle swarm optimization was used for the compensation process. © 2014 Wiley Periodicals, Inc. Int J RF and Microwave CAE 24:635–645, 2014.     

Kinetic Study of the Steam Reforming of Isobutane Using a Pt–CeO2–Gd2O3 Catalyst

Steam reforming of isobutane on a 0.5% Pt–Ce_0.8Gd_0.2O_1.9 catalyst was carried out from 300 to 700 °C under integral conditions with a gas hourly space velocity (GHSV) of 12,000 h⁻¹. The major products were H₂, CO₂, CO and CH₄. The other products produced were ethane, ethylene, propane and propylene with a total molar composition of less than 1.5%. A complete conversion of isobutane was achieved at 700 °C, Kinetic data was obtained by changing the partial pressure of the reactants and the temperature under differential conditions with a GHSV of 55,400 h⁻¹. This was done after observing stable isobutane steam reforming for 160 h and under conditions where the mass transfer limitations were insignificant. An empirical Langmuir–Hinshelwood type model that best fit the kinetic data available was developed.     

Synthesis,characterization, and rheological studies of methacrylic acid–ethyl acrylate–diallyl phthalate copolymers

Copolymerization of methacrylic acid (MAA) and ethyl acrylate (EA) was performed by the emulsion polymerization technique in the presence of a mixture of ionic and nonionic emulsifiers, at 85°C, using potassium persulfate as initiator (0.16 wt % of monomer). The molar ratio of MAA : EA varied between 44 : 56 and 54 : 46 in the monomer feed. Copolymers of MAA and EA were synthesized by incorporating diallyl phthalate (DAP) with varying concentrations (0–1.7 mol % of total monomer) in the feed. A copolymer latex of MAA, EA, and DAP was also prepared by the variable feed process. The intrinsic viscosity and gel content were determined. Copolymers were characterized by IR and NMR spectroscopic techniques. The composition of copolymers was determined by ¹H‐NMR spectra and sequential distribution from ¹³C{¹H}‐NMR spectra. The pH of the copolymer emulsion varied between 3 and 10 by addition of aqueous ammonia (23% w/w) and its effect on Brookfield viscosity was studied. The effects of copolymer composition, crosslinking agent concentration in the feed, monomer feed process, polymer solid contents, and shear rate on Brookfield viscosity were studied at pH ～ 8. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1430–1441, 2003     

A New Method for Getting Rational Approximation for Fractional Order Differintegrals

In this paper a new algorithm is presented to calculate the poles and zeros to approximate a fractional order (FO) differintegral (s^±α,α∈(0,1)) by a rational function on a finite frequency band ω∈(ω_l,ω_h). The constant phase property of the FO differintegral is the basis for development of the algorithm. Interlacing of real poles and zeros is used to achieve the constant phase. The calculations are done using the asymptotic Bode phase plot. A brief investigation is made to get a good approximation for the Bode phase plot. Two design parameters are introduced to keep the average phase close to the desired phase angle and to keep the error within the allowed bounds. A study is done to empirically understand the relationship between the error and the design parameters. The results thus obtained help in the further calculations. The algorithm is computationally simple and inexpensive, and gives a fairly good approximation of fractance frequency response on the specified frequency band.