Aging of a Pt/Al₂O₃ exhaust gas catalyst monitored by quasi in situ X-ray micro computed tomography

Catalyst aging effects were analyzed using X-ray absorption micro-computed tomography in combination with conventional characterization methods on various length scales ranging from nm to [small mu ]m to gain insight into deactivation mechanisms. For this purpose, a 4 wt% Pt/Al2O3 model exhaust gas catalyst was coated on a cordierite honeycomb and subjected to sequential thermal aging in static air at 950 [degree]C for 4, 8, 12 and 24 hours. The aging was followed on the one hand by traditional methods, i.e. CO-oxidation activity, scanning and transmission electron microscopy (SEM, TEM), and X-ray diffraction (XRD). On the other hand, all intermediate aging steps were captured by X-ray absorption micro-computed tomography ([small mu ]-CT) with 1.27 [small mu ]m voxel size using a quasi in situ approach as complementary tool. The [small mu ]-CT data allowed comparing exactly the same position after each treatment using a special alignment procedure during data analysis which took into account that the sample was remounted on the sample holder. A growth of the initially nanometer-sized Pt particles into larger crystals as well as its agglomeration was found, preferentially in voids between support grains. Sintering occurred especially around the larger particles, which is in line with the Ostwald ripening mechanism reported for this system on a nanometer scale. The distribution of chemical elements in an embedded and mechanically cross-sectioned honeycomb was additionally mapped by an electron probe micro analyzer (EPMA), which in agreement to the [small mu ]-CT results shows no diffusion of Pt into the cordierite. Together with studies on the nanometer scale, these results allow a more thorough multi-scale modeling of exhaust gas catalysts, especially also during aging

Adipokinetic hormone enhances nodule formation and phenoloxidase activation in adult locusts injected with bacterial lipopolysaccharide

Interactions between the locust endocrine and immune systems have been studied in vivo in relation to nodule formation and activation of the prophenoloxidase cascade in the haemolymph. Injection of bacterial lipopolysaccharide (LPS) extracted from Escherichia coli induces nodule formation in larval and adult locusts but does not increase phenoloxidase activity in the haemolymph. Nodule formation starts rapidly after injection of LPS and is virtually complete within 8 h, nodules occurring mainly associated with the dorsal diaphragm on either side of the heart, but sometimes with smaller numbers associated with the ventral diaphragm on either side of the nerve cord. Co-injection of adipokinetic hormone-I (Lom-AKH-I) with LPS stimulates greater numbers of nodules to be formed in larval and adult locusts, and activates phenoloxidase in the haemolymph of mature adults but not of nymphs. The effect of co-injection of Lom-AKH-I with LPS on nodule formation is seen at low doses of hormone; only 0.4 pmol of Lom-AKH-I per adult locust is needed to produce a 50% increase in the number of nodules formed. When different components of LPS from the E. coli Rd mutant are tested, the mono- and the diphosphoryl Lipid A components have similar effects to the intact LPS. Remarkably, detoxified LPS activates phenoloxidase in the absence of Lom-AKH-I, although co-injection with hormone does enhance this response. Both diphosphoryl Lipid A and detoxified LPS induce a level of nodule formation that is enhanced by co-injection of Lom-AKH-I, but monophosphoryl Lipid A does not initiate nodule formation even when injected with hormone. Co-injection of a water-soluble inhibitor of eicosanoid synthesis, diclofenac (2-[(2, 6-dichlorophenyl)amino] benzeneacetic acid), reduces nodule formation in response to injections of LPS (both in the absence and presence of hormone) in a dose-dependent manner, but does not prevent activation of phenoloxidase in adult locusts. It is shown that nodule formation and activation of the prophenoloxidase in locust haemolymph can both be enhanced by Lom-AKH–I, but it is argued that these processes involve distinct mechanisms in which eicosanoid synthesis is important for nodule formation, but not for the increased phenoloxidase activity

Covering one eye in fixation-disparity measurement causes slight movement of fellow eye

In the subjective measurement of fixation disparity (FD), the subject fuses contours presented in the peripheral macular areas of both eyes (fusion lock). The position of the eyes relative to each other is monitored by means of two haploscopically seen vertical lines presented in the central macular area, one above and one below a binocularly seen horizontal line. The subject is instructed to shift one of the vertical lines horizontally until the two are aligned, while fixating their intersection with the horizontal line. It has recently been questioned whether the foveolae really are pointed towards the perceived intersection. In this study, we monitored the position of one eye while intermittently covering the fellow eye, while the subject maintained fixation of the intersection of the remaining vertical line and the horizontal line. We found slight differences in position of the measured eye, depending on whether the other eye was covered or not, i.e. depending on the presence or absence of fusion in the macular periphery. These differences were more pronounced in the non-dominant eye

Improvement in NO2 Sensing Properties of Semiconductor-Type Gas Sensors by Loading of Au Into Porous In2O3 Powders

Porous (pr-) In2O3 powders loaded with and without noble metals (Au, Pd, or Pt) were prepared by ultrasonic spray pyrolysis employing the PMMA microspheres as a template (typical particle size (ps): 28 or 70 nm with a diameter), and their NO2 sensing properties were examined. The Au loading on the pr-In2O3 was effective to increase the NO2 response at lower operating temperature (?200°C), while the metal loading of Pd or Pt were hardly effective. In addition, a decrease in the PMMA microspheres (from 70 to 28 nm in ps) largely increased the NO2 response,and an optimized amount of Au loaded on the pr-In2O3 sensor was 1.0 wt%. The decrease in the thickness of the sensing layer improved the NO2 response and response speed. It was suggested that the Au loading enhanced the amount of the negatively adsorbed NO2 on the bottom part of the sensing layer, leading to the increase in the NO2 response. Furthermore, the introduction of additional macropores (ps: 150 nm) to the 1.0 wt% Au loaded pr-In2O3 sensor increased the response to a low concentration of NO2 (0.025 ppm) at 30°C. Therefore, it was found that easy gas diffusion from the surface to the bottom part of the sensing layer increased the effective concentration of NO2, and thus the NO2 response was increased

Innovative Wellnessmarketing in Hotels

Ziel dieser Arbeit ist es ein modernes und innovatives Wellness- und Hotelmarketing aufzuzeigen, das sich an dem Trend Wellness und Gesundheit orientiert. Die Bachelorarbeit zeigt die Grundlagen und Aufgaben des Marketings, erläutert die Besonderheiten des Hotel- und Wellnessmarketing als Dienstleistungsmarketing und zeigt die traditionellen und innovativen Kommunikationsinstrumente. Abschließend werden Handlungsempfehlungen gegeben und die Erfolgsfaktoren für ein erfolgreiches und innovatives Wellnessmarketing herausgearbeitet

Boletín informativo de lenguas

El aprendizaje no depende exclusivamente de la pericia del profesor. La relación interpersonal entre alumno y profesor, el contexto en el que vive el alumno y la motivación para el aprendizaje influyen bastante. En un curso de lengua extranjera, la primera competencia que se promueve es la comunicación, pero se deben promover otras cualidades como la creatividad, la iniciativa y la motivación. Se analiza la relación entre motivación y satisfacción de los alumnos.MadridBiblioteca de Educación del Ministerio de Educación, Cultura y Deporte; Calle San Agustín, 5 - 3 Planta; 28014 Madrid; Tel. +34917748000; [email protected]

Árbol Estratégico = Strategic tree

ResumenEl 80% de las empresas creadas hoy en España son microempresas o pequeñas empresas. La mayoría de ellas fueron creadas intuitivamente con un bajo nivel de formación en el área de gestión y administración. La intuición, difícil de gestionar en grandes estructuras jerarquizadas, es una de las grandes ventajas de estas microempresas. Hoy las personas que manejan lo intuitivo son más valoradas y requeridas en lugares estratégicos de toma de decisiones. El árbol estratégico nace con el gen de lo intuitivo y pretende ser una herramienta válida para que la intuición se desarrolle estratégicamente de forma ordenada. Abstract Almost the 80% of the companies created in Spain are micro or small companies. Most of them were created in an intuitive way with a low level of formation in the management and administration area. The intuition, hard management for the big hierarchical structures, is one of the advantages of these micro companies. People that manage the intuition are more valuable and required in a strategic space for took over decisions. The strategic tree has borned to be intuitive and expect to be a valid tool so the intuition could be developed strategically in an organized way