Characterization and catalytic activity of soft-templated NiO-CeO2 mixed oxides for CO and CO2 co-methanation

Nanosized NiO,CeO₂ and NiO-CeO₂ mixed oxides with different Ni/Ce molar ratios were prepared by the soft template method.All the samples were characterized by different techniques as to their chemical composition,structure,morphology and texture.On the catalysts submitted to the same reduction pretreatment adopted for the activity tests the surface basic properties and specific metal surface area were also determined.NiO and CeO₂ nanocrystals of about 4 nm in size were obtained,regardless of the Ni/Ce molar ratio.The Raman and X-ray photoelectron spectroscopy results proved the formation of defective sites at the NiO-CeO₂ interface,where Ni species are in strong interaction with the support.The microcalorimetric and Fourier transform infrared analyses of the reduced samples highlighted that,unlike metallic nickel,CeO₂ is able to effectively adsorb CO₂,forming carbonates and hydrogen carbonates.After reduction in H2 at 400°C for 1 h,the catalytic performance was studied in the CO and CO₂ co-methanation reaction.Catalytic tests were performed at atmospheric pressure and 300°C,using CO/CO₂/H₂ molar compositions of 1/1/7 or 1/1/5,and space velocities equal to 72000 or 450000 cm³?h^-1?gcat^-1.Whereas CO was almost completely hydrogenated in any investigated experimental conditions,CO₂ conversion was strongly affected by both the CO/CO₂/H₂ ratio and the space velocity.The faster and definitely preferred CO hydrogenation was explained in the light of the different mechanisms of CO and CO₂ methanation.On a selected sample,the influence of the reaction temperature and of a higher number of space velocity values,as well as the stability,were also studied.Provided that the Ni content is optimized,the NiCe system investigated was very promising,being highly active for the CO_x co-methanation reaction in a wide range of operating conditions and stable(up to 50 h)also when submitted to thermal stress.     

Memorizing while walking: Increase in dual-task costs from young adulthood to old age.

The dual task of memorizing word lists while walking was predicted to become more difficult with age because balance and gait are in greater need of "attentional resources." Forty-seven young (ages 20–30 years), 45 middle-aged (40–50), and 48 old (60–70) adults were trained to criterion in a mnemonic technique and instructed to walk quickly and accurately on 2 narrow tracks of different path complexity. Then, participants encoded the word lists while sitting, standing, or walking on either track; likewise, speed and accuracy of walking performance were assessed with and without concurrent memory encoding. Dual-task costs increased with age in both domains; relative to young adults, the effect size of the overall increase was 0.98 standard deviation units for middle-aged and 1.47 standard deviation units for old adults. It is argued that sensory and motor aspects of behavior are increasingly in need of cognitive control with advancing age. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Predictors of subjective physical health and global well-being: Similarities and differences between the United States and Germany.

Predictors of subjective physical health and global well-being were compared in a representative U.S. (N?=?2,400) and a German (N?=?1,607) sample of adults (age range: 25–65 years). Because of cultural overlap between Western industrialized nations, similarities in predictive patterns were expected. Differences in the economic and social systems as well as the cultural background, however, should also generate differences. As expected, the overall predictive power of the three sets of predictors (sociostructural variables, personality traits, and self-regulatory characteristics) was sizable in both countries. The strongest unique predictors were self-regulatory indicators for subjective physical health and personality traits for global well-being. In addition, however, theory-consistent country differences emerged in how personal and social resources seem to be orchestrated to maximize well-being. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Seeds of wisdom: Adolescents' knowledge and judgment about difficult life problems.

The present study examined adolescents' wisdom-related knowledge and judgment with a heterogeneous sample of 146 adolescents (ages 14–20 years) and a comparison sample of 58 young adults (ages 21–37 years). Participants responded to difficult and ill-defined life dilemmas; expert raters evaluated these responses along 5 wisdom criteria. Our findings confirmed that in contrast to adulthood, adolescence is a major period for normative age-graded development in knowledge about difficult life problems. Adolescents performed at lower levels than young adults but also demonstrated substantial age increments in performance. As expected, adolescents' performance varied as a function of criterion and gender. These results hold implications for research on adolescent development and for the development of wisdom-related knowledge and judgment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparative case studies on ring gear fault diagnosis of planetary gearboxes using vibrations and acoustic emissions

The analysis of vibrations and acoustic emissions (AE) are two recognized non-destructive techniques used for machine fault diagnosis. In recent years, the two techniques have been comparatively evaluated by different researchers with experimental tests. Several evaluations have shown that the AE analysis has a higher potential than the vibration analysis for fault diagnosis of mechanical components for certain cases. However, the distance between the AE sensor and the fault is an important factor that can considerably decrease the potential to detect damage and that has not been sufficiently investigated. Moreover, the comparisons have not yet addressed conditions of slow speed that for example are usual for wind turbine gearboxes. Therefore, in this paper we present two comparative case studies that address both topics. Both case studies consider planetary gearboxes with faults in their ring gears. The first case study corresponds to a small planetary gearbox in which the AE and vibration sensors were installed together at two different positions. The second case study corresponds to a full-size wind turbine gearbox in which three pairs of AE and vibration sensors were installed on the outside of the ring gear from a low-speed planetary stage. The results of the evaluations demonstrate the important influence of the distance between sensors and fault. Despite this, the good results from the AE analysis indicate that this technique should be considered as an important complement to the traditional vibration analysis. The main contribution of this paper is comparing AE and vibration analysis by using not only experimental data from a small planetary gearbox but also from a full-size wind turbine gearbox. The comparison addresses the topics of proximity of the sensor to the fault and low-speed conditions.

     

Web Application Commercial Design for Financial Entities Based on Business Intelligence

Multiple customer data management has become a focus of attention in big organizations. Although much information is available, it does not translate into significant profitable value-added services. We present a design of a commercial web application based on business intelligence that generates information on social and financial behavior of clients in an organization; with the purpose of obtain additional information that allows to get more profits. This app will provide a broader perspective for making strategic decisions to increase profits and reduce internal investment costs. A case in point is the financial sector, a group of financial entities were used to make measurements and test them. A design to build a web application aimed at achieving a large and ambitious goal by means of defined tools reflecting clients’ business needs is proposed. In this research, different techniques and technologies are explored, such as diagrams, frameworks, design, architecture, model entity-relationship, tables, equations, mental maps and development tools. Through the Personal Software Process methodology and with the help of information extraction, consolidation, and visualization, the implementation can be carried out. This article provides the importance of implementing business intelligence in an organization and expands on the steps needed for the implementation of this valuable technology.     

Acoustic Emission Source Localization in Ring Gears from Wind Turbine Planetary Gearboxes

Forschung im Ingenieurwesen - Condition monitoring and fault diagnosis are methods to achieve a higher reliability for complex mechanical systems. Due to the ability of acoustic emission...     

The Adsorption of VO(acac)2 on a Mesoporous Silica Support by Liquid Phase and Gas Phase Modification to Prepare Supported Vanadium Oxide Catalysts

Supported vanadium oxide catalysts are prepared by adsorption and subsequent calcination of the vanadyl acetylacetonate complex on silica by liquid phase and gas phase modification. The influence of the pretreatment temperature and the effect of the solvent in the liquid phase are discussed. Two types of gas phase deposition processes are used: flow-type reactions and vacuum deposition. The bonding mechanism, the influence of pretreatment temperature of the support and the influence of the reaction temperature are investigated by FTIR, XRD, TGA and chemical analysis. After calcination the obtained vanadium oxide layer is characterized by XRD and UV-Vis diffuse reflectance spectroscopy. The gas phase modification enables the creation of well dispersed supported VO_x catalysts. Loadings up to 1.4 mmol g^-1 (7 wt% V) without the formation of a crystalline fraction can be achieved. The selective oxidation of methanol to formaldehyde is used as a probe reaction to assess the catalytic activity and selectivity of the catalysts. It is shown that not the concentration of vanadium species, but their surface configuration is the determining factor in catalytic reactions.     

Test structures to measure the Seebeck coefficient of CMOS ICpolysilicon

We report on two thermal characterization structures to measure the Seebeck coefficient α of CMOS IC polysilicon thin films relevant for integrated thermal microtransducers. The test structures were fabricated using a commercial 1.2 μm CMOS process of Austria Mikro Systeme (AMS). The fabrication of the first structure relies on silicon micromachining. In contrast the second, planar, structure is ready for measurement after IC fabrication. The temperature dependent α of the two polysilicon layers of the AMS process was measured with both devices. The agreement between the thermoelectric coefficients obtained with the two types of structures is better than 2.1 μV at 300 K