Nitric Oxide Reduction Using Hydrogen Over Perovskite Catalysts with Promotional Effect of Platinum on Catalytic Activity

The catalytic activities of strontium substituted La_0.7Sr_0.3MnO₃ type perovskite catalysts for NO reduction using H₂ as reducing agent has been studied, which is further improved by incorporation of Pt outside (0.1 wt.%Pt/La_0.7Sr_0.3MnO₃) and inside (La_0.7Sr_0.3Mn_0.97Pt_0.03O₃) the perovskite lattice structure. Pt shows excellent enhancement in catalytic selectivity towards N₂ when supported on the perovskite. The catalysts were characterized using thermo-gravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM) and specific surface area. Catalysts evaluations were carried out using thermo-gravimetric analysis coupled with mass spectra (TG-MS).     

Enhanced optoelectronics properties of europium(III) complexes with β-diketone and nitrogen heterocyclic ligands

Preparation and photoluminescence behavior of six new europium complexes with β-diketone 1-(2-hydroxy phenyl)-3-phenylpropane-1,3-dione (HPPP) and bathophenanthroline (batho), 2,2′-bipyridyl (bipy), 2,2′-biquinoline (biq), neocuproin (neo) and 1,10-phenanthroline (phen) are reported in solid state. The ligand (HPPP) and complexes Eu(HPPP)₃·H₂O (1), Eu(HPPP)₃·phen (2), Eu(HPPP)₃·batho (3), Eu(HPPP)₃·bipy (4), Eu(HPPP)₃·biq (5) and Eu(HPPP)₃·neo (6) were characterized by means of elemental analysis, infrared spectroscopy, proton nuclear magnetic resonance (¹H-NMR). The optical properties, thermal stability and crystalline nature were investigated by photoluminescence spectroscopy, thermogravimetric analysis and XRD respectively. The emission spectra show narrow intense emission band of central europium (III) metal ion that arise from the high intense ⁵D₀ → ⁷F₀ transition. The introduction of ancillary ligands like batho, bipy, biq, neo, phen enlarged the π-conjugation system in complexes as a result higher luminescence intensity, longer life time (τ) and higher quantum efficiency (η) observed in europium ternary complexes in comparison to Eu(HPPP)₃·H₂O (1). Based on the emission spectra, the luminescence decay curve was measured which indicated that the transfer of energy from HPPP ligand to the europium metal is more efficient in complexes 2–6 than complex 1.     

Magnetic proximity effect as a pathway to spintronic applications of topological insulators

Spin-based electronics in topological insulators (TIs) is favored by the long spin coherence(1,2) and consequently fault-tolerant information storage. Magnetically doped TIs are ferromagnetic up to 13 K,(3) well below any practical operating condition. Here we demonstrate that the long-range ferromagnetism at ambient temperature can be induced in Bi(2-x)Mn(x)Te(3) by the magnetic proximity effect through deposited Fe overlayer. This result opens a new path to interface-controlled ferromagnetism in TI-based spintronic devices.     

Assessing long-term changes in cadmium availability from Cd-enriched fertilizers at different pH by isotopic dilution

The application of commercial phosphate fertilizers containing Cd as an impurity is an important source of Cd to agricultural soils. The changes in the Cd status and its bioavailability in soils taken from a field trial were investigated after several years of application of fertilizers with a range of Cd contamination levels to soils. Various soil pH regimes were achieved by liming. The isotopic dilution technique was used to determine both the plant available (L-value) and isotopically exchangeable (E-value) Cd pools in soils. Firstly, we found that the L-values after 10 year of application were significantly higher at pH 5.0 than at pH 6.0, and this was reflected in the increased Cd uptake by wheat at the lower pH. There was no significant effect of the rate of soil Cd application on the L-values. Although long-term use of Cd enriched P-fertilizers increased the total concentration of Cd in soil, the impact on wheat production was insignificant. Most cultivated soils in Norway are maintained at soil pH between 5.5 and 6.5 by frequent liming. That brings up the second interesting finding, the possible impurity of lime used in this experiment. The lime was not analysed, as it was unexpected that liming might raise the total content of soil Cd substantially. That seems, however, to have been the case for this experiment since we find increase of total Cd even in the low-Cd input blocks of the trial.     

The Effect of Mold Temperature on the Performance of Injection Molded Poly(lactic acid)‐Based Bioplastic

This research investigates the effects of processing parameters, namely molding temperature on the mechanical performance of impact‐modified poly(lactic acid) (PLA). Polymer crystallization dictates many of the final properties of the material. Increasing the mold temperature, crystallization may progress to a further stage, increasing crystallinity. Molding at a lower temperature, and producing a highly amorphous polymer can increase the mechanical properties, namely elongation and impact strength. Molding at 30 versus 90 °C improved the elongation from 22 to 243% and the impact strength from 67 to 133 J · m^?1. This improvement is not without its drawbacks. By molding at 30 °C, the polymer becomes very amorphous, and thus is more susceptible to unwanted processes such as physical aging.

     

红外搜索跟踪系统作用距离等效折算

传统的红外搜索跟踪系统作用距离方程存在一定的局限性,没有考虑背景辐射的影响。为了完成红外搜索跟踪系统对天空背景下快速运动小目标,在不同气象和飞行条件下作用距离的等效折算,推导了考虑天空背景辐射的点目标红外搜索跟踪作用距离模型,根据模型对不同气象条件下某型红外搜索跟踪系统对某型靶机的作用距离进行了推算,并利用红外搜索跟踪系统对靶机的飞行试验实测数据对模型进行验证,结果表明,模型精度较高,可以用于外场试验时红外搜索跟踪系统作用距离的等效折算。最后,利用模型对某型红外搜索跟踪系统对特定气象条件、不同飞行条件下某型导弹的作用距离进行了等效折算。     

Sol-Gel Derived Nanocrystalline Lanthanum Doped Lead Zirconate Titanate Thin Films Studied for Solitary Waves Propagation

Nanocrystalline PLZT thin films of composition Pb_1-xLa_xZr_0.52Ti_0.48 (x = 0, 2, 5%) were deposited on silicon substrates by sol-gel process using lead acetate trihydrate, lanthanum nitrate hydrate, zirconium propoxide and titanium propoxide as lead, lanthanum, zirconium and titanium precursor materials. Experimental studies have been made on solitary waves in 2 mol% lanthanum doped sol-gel derived lead zirconate titanate thin films. The solitary waves are generated under the influence of external alternating electric field, which has the same frequency as the external field. These solitary waves propagate through the thin film upto its boundary and then reflect back. The magnitude of the solitary waves attenuates as they move away from the electrodes and their phase reverses on reflection. For certain frequencies of the external electric field, solitary waves exhibit resonance effect. Distortion in hysteresis loops has been demonstrated on the basis of solitary waves propagation in the film having different electrode area.     

Synthesis and characterization of low-cost ceramic membranes from fly ash and kaolin for humic acid separation

Ceramic microfiltration membranes were prepared using five different compositions formulated with different amounts of fly ash and kaolin and sintered at 900 °C. The SEM analysis evidenced a large number of small pores on the surface of kaolin-rich membranes. The M4 membrane prepared using 25% fly ash and 50% kaolin was found to be optimum as it had a good combination of pore size (0.885 μm), porosity (42.7%), mechanical strength (43.6MPa), and chemical stability (<3% weight loss in acid and 0.02% in base), and this membrane was successfully applied in separation of humic acid from water. The permeate flux data fitted very closely with cake-filtration model, indicating the formation of a cake layer on membrane surface. Membrane fouling was found to be reversible and easily negated by cleaning and backflushing. The regenerated membrane showed better rejection of humic acid than fresh membrane with a flux recovery of above 80%.     

Vital Sign Monitoring System for Healthcare Through IoT Based Personal Service Application

The most burning issues worldwide at present are the availability, accessibility, and affordability of the equitable healthcare services for all. It is getting more severe for developing countries due to increasing population and chronic diseases. The emerging technological interventions in the field of Internet of Things (IoT)-based healthcare systems are a promising solution to meet the general public's healthcare needs. Therefore, an IoT-enabled vital sign monitoring system has been presented in this paper. The presented system can monitor various vital signs in real-time and store the recorded trends locally. The system can also send the data into cloud for further analysis. Abnormality detection with alert notification and automatic calculation of early warning score has been implemented. An Android application is developed to store the vital signs records on a personal server to avoid the burden and maintenance cost of the central medical server. The presented system is straightforward, compact, portable and easy to operate through personal service application. Also, the presented system is compared with the most recent work available in the field.

     

Ultrasonic study on molecular interactions in binary mixtures of formamide with 1-propanol or 2-propanol

Ultrasonic speeds have been measured at 298.15 K and 308.15 K for mixtures of formamide+1-propanol or 2-propanol. For an equimolar mixture, excess molar compressibility follows the sequence of 1-propanol N 2-propanol. The ultrasonic speed data are correlated by various correlations such as Nomoto's relation, van Dael's mixing relation and impedance dependence relation, and analyzed in terms of Jacobson's free length theory and Schaaff's collision factor theory. Excess isentropic compressibility is calculated from ex-perimental ultrasonic speed data and previously reported excess volume data. The excess molar ultrasonic speed and isentropic compressibility values are fitted to Redlich–Kister polynomial equation. Other proper-ties such as molecular association, avallable volume, free volume, and intermolecular free length are also calculated. The excess isentropic compressibility data are also interpreted in terms of graph theoretical ap-proach. The calculated isentropic compressibility values are well consistent with the experimental data. It is found that the interaction between formamide and propanol increases when hydroxyl group attached to a carbon atom has more–CH3 groups.