Zinc acetylacetonate hydrate adducted with nitrogen donor ligands: Synthesis, spectroscopic characterization, and thermal analysis

We report synthesis, spectroscopic characterization, and thermal analysis of zinc acetylacetonate complex adducted by nitrogen donor ligands, such as pyridine, bipyridine, and phenanthroline. The pyridine adducted complex crystallizes to monoclinic crystal structure, whereas other two adducted complexes have orthorhombic structure. Addition of nitrogen donor ligands enhances the thermal property of these complexes as that with parent metal-organic complex. Zinc acetylacetonate adducted with pyridine shows much higher volatility (106 degrees C), decomposition temperature (202 degrees C) as that with zinc acetylacetonate (136 degrees C, 220 degrees C), and other adducted complexes. All the adducted complexes are thermally stable, highly volatile and are considered to be suitable precursors for metal organic chemical vapor deposition. The formation of these complexes is confirmed by powder X-ray diffraction, Fourier transform infrared spectroscopy, mass spectroscopy, and elemental analysis. The complexes are widely used as starting precursor materials for the synthesis of ZnO nanostructures by microwave irradiation assisted coating process. (c) 2015 Elsevier B.V. All rights reserved.

Differential viability response of prokaryotes and eukaryotes to high strength pulsed magnetic stimuli

The present study examines the efficacy of a high strength pulsed magnetic field (PMF) towards bacterial inactivation in vitro, without compromising eukaryotic cell viability. The differential response of prokaryotes Staphylococcus aureus (MESA), Staphylococcus epidermidis, and Escherichia coli], and eukaryotes C2C12 mouse myoblasts and human mesenchymal stem cells, hMSCs] upon exposure to varying PMF stimuli (1-4 T, 30 pulses, 40 ms pulse duration) is investigated. Among the prokaryotes, similar to 60% and similar to 70% reduction was recorded in the survival of staphylococcal species and E. coli, respectively at 4 T PMF as evaluated by colony forming unit (CPU) analysis and flow cytometry. A 2-5 fold increase in intracellular ROS (reactive oxygen species) levels suggests oxidative stress as the key mediator in PMF induced bacterial death/injury. The 4 T PMF treated staphylococci also exhibited longer doubling times. Both TEM and fluorescence microscopy revealed compromised membranes of PMF exposed bacteria. Under similar PMF exposure conditions, no immediate cytotoxicity was recorded in C2C12 mouse myoblasts and hMSCs, which can be attributed to the robust resistance towards oxidative stress. The ion interference of iron containing bacterial proteins is invoked to analytically explain the PMF induced ROS accumulation in prokaryotes. Overall, this study establishes the potential of PMF as a bactericidal method without affecting eukaryotic viability. This non-invasive stimulation protocol coupled with antimicrobial agents can be integrated as a potential methodology for the localized treatment of prosthetic infections. (C) 2015 Elsevier B.V. All rights reserved.

On the contributions of different micromechanisms for enhancement in the strength of TI-6Al-4V alloy upon B addition: A nanomechanical analysis

The addition of small amount of boron to Ti and it alloys refines the as-cast microstructure and enhances the mechanical properties. In this paper, we employ nanoindentation on each of the constituent phases in the microstructure and `rule-of-mixture' type analysis to examine their relative contributions to the strength enhancement in a Ti-6Al-4V alloy modified with 0.3 wt% B. Our results indicate to two main contributors to the relatively higher flow strength of B-modified alloy vis-a-vis the base alloy: (a) strengthening of alpha phase due to the reduction in the effective slip length that occurs as a result of the microstructural refinement that occurs upon B addition, and (b) composite strengthening caused by the TiB whiskers present in the alloy. (C) 2015 Elsevier B.V. All rights reserved.

Microhardness Studies of Vapour Grown Tin (II) Sulfide Single Crystals

Earth abundant tin sulfide (SnS) has attracted considerable attention as a possible absorber material for low-cost solar cells due to its favourable optoelectronic properties. Single crystals of SnS were grown by physical vapour deposition (PVD) technique. Microindentation studies were carried out on the cleaved surfaces of the crystals to understand their mechanical behaviour. Microhardness increased initially with the load, giving sharp maximum at 15 g. Quenching effect has increased the microhardness, while annealing reduced the microhardness of grown crystals. The hardness values of as-grown, annealed and quenched samples at 15 g load are computed to be 99.69, 44.52 and 106.29 kg/mm(2) respectively. The microhardness of PVD grown crystals are high compared to CdTe, a leading low-cost PV material. The as-grown faces are found to be fracture resistant.

Error exponent analysis of energy-based Bayesian decentralized spectrum sensing under fading

This paper considers decentralized spectrum sensing, i.e., detection of occupancy of the primary users' spectrum by a set of Cognitive Radio (CR) nodes, under a Bayesian set-up. The nodes use energy detection to make their individual decisions, which are combined at a Fusion Center (FC) using the K-out-of-N fusion rule. The channel from the primary transmitter to the CR nodes is assumed to undergo fading, while that from the nodes to the FC is assumed to be error-free. In this scenario, a novel concept termed as the Error Exponent with a Confidence Level (EECL) is introduced to evaluate and compare the performance of different detection schemes. Expressions for the EECL under general fading conditions are derived. As a special case, it is shown that the conventional error exponent both at individual sensors, and at the FC is zero. Further, closed-form lower bounds on the EECL are derived under Rayleigh fading and lognormal shadowing. As an example application, it answers the question of whether to use pilot-signal based narrowband sensing, where the signal undergoes Rayleigh fading, or to sense over the entire bandwidth of a wideband signal, where the signal undergoes lognormal shadowing. Theoretical results are validated using Monte Carlo simulations. (C) 2015 Elsevier B.V. All rights reserved.

On variant distribution and coarsening behavior of the a phase in a metastable beta titanium alloy

The stereology, variant distribution and coarsening behavior of semicoherent alpha(hcp) precipitates in a beta(bcc) matrix of a Ti5553 alloy has been analyzed, and a dominant 3-variant cluster has been observed in which the variants are related to each other by an axis-angle pair <<11(2)over bar> 0 >/60 degrees. Shape and spatial distribution independent elastic self and interaction energies for all pairwise and triplet combinations of a have been calculated and it is found that the 3-cluster combination that is experimentally observed most frequently has the lowest energy for the semicoherent state. The coarsening behavior of the delta distribution follows LSW kinetics after an initial transient, and has been modeled by phase field methods. (C) 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Benchmark analytical solutions from beams with shared eigenpair

Structures with governing equations having identical inertial terms but somewhat differing stiffness terms can be termed flexurally analogous. An example of such a structure includes an axially loaded non-uniform beam and an unloaded uniform beam, for which an exact solution exists. We find that there exist shared eigenpairs (frequency and mode shapes) for a particular mode between such structures. Non-uniform beams with uniform axial loads, gravity loaded beams and rotating beams are considered and shared eigenpairs with uniform beams are found. In general, the derived flexural stiffness functions (FSF's) for the non-uniform beams required for the existence of shared eigenpair have internal singularities, but some of the singularities can be removed by an appropriate selection of integration constants using the theory of limits. The derived functions yield an insight into the relationship between the axial load and flexural stiffness of axially loaded beam structures. The derived functions can serve as benchmark solutions for numerical methods. (C) 2016 Elsevier Ltd. All rights reserved.

The 2014 M-w 6.1 Bay of Bengal, Indian Ocean, Earthquake: A Possible Association with the 85 degrees E Ridge

Oceanic intraplate earthquakes are known to occur either on active ridge-transform structures or by reactivation of their inactive counterparts, generally referred to as fossil ridges or transforms. The Indian Ocean, one of the most active oceanic intraplate regions, has generated large earthquakes associated with both these types of structures. The moderate earthquake that occurred on 21 May 2014 (M-w 6.1) in the northern Bay of Bengal followed an alternate mechanism, as it showed no clear association either with active or extinct ridge-transform structures. Its focal depth of >50 km is uncommon but not improbable, given the similar to 90 Ma age of the ocean floor with 12-km-thick overlying sediments. No tectonic features have been mapped in the near vicinity of its epicenter, the closest being the 85 degrees E ridge, located similar to 100 km to its west, hitherto regarded as seismically inactive. The few earthquakes that have occurred here in the past are clustered around its southern or northern limits, and a few are located midway, at around 10 degrees N. The 2014 earthquake, sourced close to the northern cluster, seems to be associated with a northwest-southeast-oriented fracture, located on the eastern flanks of the 85 degrees E ridge. If this causal association is possible, we believe that reactivation of fossil hotspot trails could be considered as another mechanism for oceanic intraplate seismicity.

振荡边界层研究及其应用

综述了振荡边界层的研究现状, 包括：层流边界层,转捩和湍流边界层的理论、数值和实验 研究的最新进展。在自然界,最典型的例子是波浪、潮汐作用下的水底边界层.同时讨论了水底边界层的特点及其中物质输送的动力学过程,还给出了实际应用的例子。

Influencia de diferentes periodos de destete en conejas primiparas en el municipio de Diriamba, Departamento de Carazo, Nicaragua

Este trabajo fue realizado en la Quinta "Myriam", ubicada en el municipio de Diriamba, departamento de Carazo, Nicaragua, propiedad del Dr. Jorge Ferreira. La ubicación geográfica del municipio está comprendida entre los 11° 50' y 12° 00' de Latitud Norte y entre los 86° 00' y 86° 15' de Longitud Oeste, cuenta con una elevación de 551 m.s.n.m., los datos meteorológicos de la zona en los últimos cuatro años (90-93) en cuanto a temperatura, humedad relativa y precipitación promedio fueron: 23.8 °C, 84% y 1184,5 mm respectivamente, (INETER, Departamento de Estadística, 1993). En el presente ensayo, se utilizó un diseño estadístico completamente aleatorizado (DCA), mediante el cual se evaluó el efecto de 3 tratamientos (15, 30 y 45 días de destete) sobre las variables Peso de la Camada al Destete (PCD), Peso de la Madre al Destete (PMD), Peso de la Madre al Segundo Parto (PSP), Ganancia Media Diaria del Parto 1 al Parto 2 (GMDp 1.P2) , con 4 repeticiones por tratamiento, éstas repeticiones estuvieron constituidas por conejas primíparas, las cuales tuvieron un peso que osciló entre 3 - 3.18 kg. y edad homogénea de 7 meses. Las variables fueron sometidas a la prueba de Duncan para determinar la superioridad en rango por tratamiento. Mediante el análisis de varianza se encontró que el efecto de los tratamientos resultó ser altamente significativo sobre la variable Peso de la Camada al Destete (PCD) (P0.01), significativo sobre las variables Peso de la Madre al Segundo Parto (PSP) y Ganancia Media Diaria del Parto 1 al Parto 2 (GMD p 1.P2) (P0.1) y no significativo sobre la variable Peso de la Madre al Destete (PMD) (NS). El efecto de la covariable Peso al Primer Parto (P1P) resultó ser altamente significativo sobre las variables Peso de la Madre al Destete (PMD) y Peso de la Madre al Segundo Parto (PSP) (P0.01). Después de someter las variables a la prueba de DUNCAN se encontraron los siguientes promedios por tratamiento: Peso de la Camada al Destete (PCD) ; T.15 días 1.538 kg P.V.(C), T.30 días 3.360 kg P.V. (B), T.45 días 4.523 kg P.V. (A), Peso de la Madre al Destete (PMD); T.15 días 3.649 kg P.V. (A) T.30 días 3.549 kg P.V. (A), T.45 dias 3.493 kg P.V.(A). Peso de la Madre al Segundo Parto (PSP); T.15 días 3. 449 kg P.V. (B), T.30 días 3.628 kg P.V. (AB), T.45 días 3.777 kg P.V.(A). Ganancia Media Diaria del Parto 1 al Parto 2 (GMD p 1.P2) T .15 días (2.071 g (B), T.30 días 2.718 g (AB), T.45 días 2. 975 g (A). Los promedios y desviaciones standard para las variables Ganancia Media Diaria del Parto 1 al Destete 1 (GMDp1-D1)y Ganancia Media Diaria del Destete l al Parto 2 (GMDD1.P2) por tratamiento fueron: GMD P1-D1; T.l5 días 3.84 g ± 0.50 g, T.30 días 2.54 g ± 0.64 g, T.45 días 2.37 g ± 0.72 g. GMD D1-P2; T.l5 días 2.26 g ± 0.54 g, T.30 días 3.17 g ± 0.74 g, T.45 días 3.93 g ± 0.28 g. Se encontró que el alimento tipo único suministrado a los animales bajo experimentación, cumplió con los requerimientos nutricionales de la especie estudiada. Los costos encontrados por hembra, por tratamiento, fueron C$ 197.21 destete de 15 días, C$ 220.28 destete de 30 días, C$ 243 .1.4 destete de 45 días. Los costos por gazapo destetado fueron de C$ 5.48 destete de 15 días, C$ 6.12 destete de 30 días, C$ 8.10 destete de 45 días.

Estudio preliminar sobre el comportamiento reproductivo de vacas de doble propósito durante período parto-concepción en el municipio de Matiguás, departamento de Matagalpa

El presente estudio se realizó con el objetivo de estudiar el comportamiento reproductivo de vacas de doble propósito durante el período parto–concepción en el municipio de Matiguás, departamento de Matagalpa considerando factores como, raza, número de parto, condición corporal y localidad, Sobre el comportamiento reproductivo en ganado con encaste Pardo Suizo, Holstein y Cebú; bajo condiciones del trópico húmedo en fincas ubicadas en 7 localidades del municipio de Matiguás departamento de Matagalpa. Además se utilizó una base de registros para analizar y clasificar a las vacas en cuanto a su condición corporal posparto, número de parto y localidad. Se analizaron 33 registros reproductivos correspondientes a vacas preñadas de las 106 vacas consideradas en estudio. Las variables bajo estudio fueron intervalo parto concepción (IPC), intervalo entre parto (IEP) y distocia. En los análisis se utilizó el procedimiento de mínimos cuadrados y separación de medias por el método Duncan para evaluar el efecto de la raza, número de parto, condición corporal posparto y localidad, sobre las varia bles IPC e IEP. En cuanto a la variable distocia no se evaluó en los análisis debido a que no presento la suficiente prevalencia para ser considerada estadísticamente. Este análisis mostró un efecto no significativo (P> 0.05) de los factores considerados sobre las variables IPC e IEP. Las medias de mínimos cuadrados obtenidas fueron 87.54 +/- 18.57 días de IPC, 367.91 +/- 18.99 días de IEP y 2% de distocia. En lo que respecta a la prevalencia de patologías del tracto reproductivo se encontraron: 7% de re tención placentaria, 3% deprolapsos vaginales, 3% de folículos persistentes y 1% de atresia ovárica.

Evaluación de la susceptibilidad relativa de Plutella xylostella (L) (Lepidoptera: plutellidae) a tres aislados de Beauveria bassiana (Balls) vuill

Con el objetivo de encontrar alternativas adecuadas de manejo de Plutella xylostella (L.), una de las principales plagas del cultivo del repollo (Brassica oleracea (L.), se llevó a cabo el presente trabajo, en el laboratorio de hongos entomopatogenos del Centro Nacional de Protección Vegetal (CENAPROVE) y la Universidad Nacional Agraria (U.N.A), en el periodo comprendido entre Febrero 1991 y Enero 1992. Se evaluó la respuesta de Plutella xylostella a tres aislados de Beauveria bassiana (Bals) Vuill. Los aislados evaluados fueron 64-88, CB-32 y 116-87, con cuatro concentraciones acuosas de cada aislado correspondientes a 105, 106, 107, 108 conidias/ml, obteniéndose rangos de porcentajes de mortalidad entre 27.3%-81.50% (64-88), 29.28% -70.39% (CB-32), 5.08% -37.5% (116-87). Se calcularon las CL50 para los aislados 64-88, CB-32 y 116-87 obteniéndose los valores de 1.8 x 106, 4.41 x 106 y 4.4 x 108 conidias/ml respectivamente, siendo los aislados 64-88 y CB-32 los que se mostraron más promisorios para el control de Plutella xylostella. El aislado 64-88 mostró tendencia a ser más eficaz en el control de larvas de esta plaga. Los valores encontrados de TL50 variaron; siendo el aislado 64-88 el que obtuvo menor tiempo (3.6 días después de la inoculación) para la mayor concentración, seguido del aislado CB-32 que alcanzó valores de 5.86 días para la mayor concentración, para el aislado 116-87 no se obtuvo el TL50 esperado ya que los valores resultaron extremadamente altos, no llegando a alcanzar el 50 % de mortalidad.

High performance nanocomposite thin film transistors with bilayer carbon nanotube-polythiophene active channel by ink-jet printing

Nanocomposite thin film transistors (TFTs) based on nonpercolating networks of single-walled carbon nanotubes (CNTs) and polythiophene semiconductor [poly [5, 5′ -bis(3-dodecyl-2-thienyl)- 2, 2′ -bithiophene] (PQT-12)] thin film hosts are demonstrated by ink-jet printing. A systematic study on the effect of CNT loading on the transistor performance and channel morphology is conducted. With an appropriate loading of CNTs into the active channel, ink-jet printed composite transistors show an effective hole mobility of 0.23 cm 2 V-1 s-1, which is an enhancement of more than a factor of 7 over ink-jet printed pristine PQT-12 TFTs. In addition, these devices display reasonable on/off current ratio of 105-10 6, low off currents of the order of 10 pA, and a sharp subthreshold slope (<0.8 V dec-1). The work presented here furthers our understanding of the interaction between polythiophene polymers and nonpercolating CNTs, where the CNT density in the bilayer structure substantially influences the morphology and transistor performance of polythiophene. Therefore, optimized loading of ink-jet printed CNTs is crucial to achieve device performance enhancement. High performance ink-jet printed nanocomposite TFTs can present a promising alternative to organic TFTs in printed electronic applications, including displays, sensors, radio-frequency identification (RFID) tags, and disposable electronics. © 2009 American Institute of Physics.

Zinc oxide nanostructures and high electron mobility nanocomposite thin film transistors

This paper reports on the synthesis of zinc oxide (ZnO) nanostructures and examines the performance of nanocomposite thin-film transistors (TFTs) fabricated using ZnO dispersed in both n- and p-type polymer host matrices. The ZnO nanostructures considered here comprise nanowires and tetrapods and were synthesized using vapor phase deposition techniques involving the carbothermal reduction of solid-phase zinc-containing compounds. Measurement results of nanocomposite TFTs based on dispersion of ZnO nanorods in an n-type organic semiconductor ([6, 6]-phenyl-C61-butyric acid methyl ester) show electron field-effect mobilities in the range 0.3-0.6 cm2V-1 s-1. representing an approximate enhancement by as much as a factor of 40 from the pristine state. The on/off current ratio of the nanocomposite TFTs approach 106 at saturation with off-currents on the order of 10 pA. The results presented here, although preliminary, show a highly promising enhancement for realization of high-performance solution-processable n-type organic TFTs. © 2008 IEEE.