968 resultados para lanthanum promotion


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We have fabricated a neodymium-doped phosphate glass fiber with a silica cladding and used it to form a fiber laser. Phosphate and silicate glasses have considerably different glass transition temperatures and softening points making it hard to draw a fiber from these two glasses. A bulk phosphate glass of composition (Nd2O3)(0.011)(La2O3)(0.259)(P2O5)(0.725)(Al2O3)(0.005) was prepared and the resultant material was transparent, free from bubbles and visibly homogeneous. The bulk phosphate glass was drawn to a fiber while being jacketed with silica and the resultant structure was of good optical quality, free from air bubbles and major defects. The attenuation at a wavelength of 1.06 mu m was 0.05 dB/cm and the refractive index of the core and cladding at the pump wavelength of 488 nm was 1.56 and 1.46, respectively. The fibers were mechanically strong enough to allow for ease of handling and could be spliced to conventional silica fiber. The fibers were used to demonstrate lasing at the F-4(3/2) - I-4(11/2) (1.06 mu m) transition. Our work demonstrates the potential to form silica clad optical fibers with phosphate cores doped with very high levels of rare-earth ions (27-mol % rare-earth oxide).

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A series of Rh2/AlO3 catalysts have been prepared using untreated or pre-sulphated alumina supports. The effect of support sulphation on catalyst activity towards propene and propane combustion has been explored as a function of Rh loading. Light-off temperatures for the total oxidation of both hydrocarbons decrease with increasing Rh content, associated with a transition from small oxidic clusters to large metallic Rh particles. Sulphate promotes both propene and propane combustion equally, with the magnitude of promotion exhibiting only a weak loading dependence. Enhanced catalytic performance is accompanied by Rh reduction and sintering. © 2006 Elsevier B.V. All rights reserved.

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Neutron diffraction was used to measure the total structure factors for several rare-earth ion R3+ (La3+ or Ce3+) phosphate glasses with composition close to RAl0.35P3.24O10.12. By assuming isomorphic structures, difference function methods were employed to separate, essentially, those correlations involving R3+ from the remainder. A self-consistent model of the glass structure was thereby developed in which the Al correlations were taken into explicit account. The glass network was found to be made from interlinked PO4 tetrahedra having 2.2(1) terminal oxygen atoms, OT, at 1.51(1) Angstrom, and 1.8(1) bridging oxygen atoms, OB, at 1.60(1) Angstrom. Rare-earth cations bonded to an average of 7.5(2) OT nearest neighbors in a broad and asymmetric distribution. The Al3+ ion acted as a network modifier and formed OT-A1-OT linkages that helped strengthen the glass. The connectivity of the R-centered coordination polyhedra was quantified in terms of a parameter f(s) and used to develop a model for the dependence on composition of the A1-OT coordination number in R-A1-P-O glasses. By using recent 17 A1 nuclear-magnetic-resonance data, it was shown that this connectivity decreases monotonically with increasing Al content. The chemical durability of the glasses appeared to be at a maximum when the connectivity of the R-centered coordination polyhedra was at a minimum. The relation of f(s) to the glass transition temperature, Tg, was discussed.

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Nowadays the great public libraries in Bulgaria are gaining the appearance of digital centers which provide new informational resources and services in the digital space. The digital conversion as a way of preservation is one of the important priorities of Regional Public Library in Veliko Tarnovo. In the last few years we persistently search for possible ways of financing by national and foreign programs in this direction. In the beginning the strategy was oriented to digitalization of the funds with most urgent conversion – these of the local studies periodicals from 1878 till 1944 year. The digitalization of funds will create conditions of laying the basement of full text database of Bulgarian periodical publications. The technology that is offered gives opportunities for including other libraries in the Unified index, which can develop it into a National Unified index of periodical publications. The integrated informational environment that is created is an attractive, comfortable and useful place for work in home or at work for researchers, historians, art experts, bibliographers. The library readers use very actively all informational services of the library internet page and work competently with the on-line indexes provided there, they find the necessary title, which can be demanded later for usage in home or in the library, using electronic means again.

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The autumn training school Development and Promotion of Open Access to Scientific Information and Research is organized in the frame of the Fourth International Conference on Digital Presentation and Preservation of Cultural and Scientific Heritage—DiPP2014 (September 18–21, 2014, Veliko Tarnovo, Bulgaria, http://dipp2014.math.bas.bg/), organized under the UNESCO patronage. The main organiser is the Institute of Mathematics and Informatics, Bulgarian Academy of Sciences with the support of EU project FOSTER (http://www.fosteropenscience.eu/) and the P. R. Slaveykov Regional Public Library in Veliko Tarnovo, Bulgaria.

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The ability of Cu and Sn to promote the performance of a 20% Ni/Al2O3 catalyst in the deoxygenation of lipids to fuel-like hydrocarbons was investigated using model triglyceride and fatty acid feeds, as well as algal lipids. In the semi-batch deoxygenation of tristearin at 260 °C a pronounced promotional effect was observed, a 20% Ni-5% Cu/Al2O3 catalyst affording both higher conversion (97%) and selectivity to C10-C17 alkanes (99%) in comparison with unpromoted 20% Ni/Al2O3 (27% conversion and 87% selectivity to C10-C17). In the same reaction at 350 °C, a 20% Ni-1% Sn/Al2O3 catalyst afforded the best results, giving yields of C10-C17 and C17 of 97% and 55%, respectively, which contrasts with the corresponding values of 87 and 21% obtained over 20% Ni/Al2O3. Equally encouraging results were obtained in the semi-batch deoxygenation of stearic acid at 300 °C, in which the 20% Ni-5% Cu/Al2O3 catalyst afforded the highest yields of C10-C17 and C17. Experiments were also conducted at 260 °C in a fixed bed reactor using triolein − a model unsaturated triglyceride − as the feed. While both 20% Ni/Al2O3 and 20% Ni-5% Cu/Al2O3 achieved quantitative yields of diesel-like hydrocarbons at all reaction times sampled, the Cu-promoted catalyst exhibited higher selectivity to longer chain hydrocarbons, a phenomenon which was also observed in experiments involving algal lipids as the feed. Characterization of fresh and spent catalysts indicates that Cu enhances the reducibility of Ni and suppresses both cracking reactions and coke-induced deactivation.

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The thermal stability of porous sol-gel phosphosilicates was studied by comparing the textural features upon calcination between 400 and 550 °C. A significant loss of surface area and pore volume were observed; the first is due to thermal coarsening of the nanoparticles, and the pore volume reduction was ascribed to sintering of the most external nanoparticles producing less void volume. Lanthanum addition was investigated as thermal stabilizer. For the mesoporous phosphosilicate composition, lanthanum addition enhanced the surface area, showing a 45% and 50% improvement with respect to the La-free counterpart; the effect was much less visible for the macroporous composition.

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Background. Sports and arts based services for children have positive impacts on their mental and physical health. The charity sector provides such services, often set up in response to local communities expressing a need. The present study maps resilience promoting services provided by children's charities in England. Specifically, the prominence of sports and arts activities, and types of mental health provisions including telephone help-lines, are investigated. Findings. The study was a cross-sectional web-based survey of chief executives, senior mangers, directors and chairs of charities providing services for children under the age of 16. The aims, objectives and activities of participating children's charities and those providing mental health services were described overall. In total 167 chief executives, senior managers, directors and chairs of charities in England agreed to complete the survey. From our sample of charities, arts activities were the most frequently provided services (58/167, 35%), followed by counselling (55/167, 33%) and sports activities (36/167, 22%). Only 13% (22/167) of charities expected their work to contribute to the health legacy of the 2012 London Olympics. Telephone help lines were provided by 16% of the charities that promote mental health. Conclusions. Counselling and arts activities were relatively common. Sports activities were limited despite the evidence base that sport and physical activity are effective interventions for well-being and health gain. Few of the charities we surveyed expected a health legacy from the 2012 London Olympics. © 2010 Bhui et al; licensee BioMed Central Ltd.

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The extent to which Registered Dietitians (RD) promote exercise as part of diabetes self-management education to older diabetic adults has not been established. This study explored the exercise-related knowledge, design, and content of educational programs among RDs who were Certified Diabetes Educators (CDEs) and non-CDEs. The Exercise Teaching Questionnaire was completed by 94 CDEs and 73 non-CDEs in Florida, California, and Texas. ^ CDEs had significantly (p < 0.001) higher mean Knowledge, Design, and Content scores (11.8 ± 1.1, 33.5 ± 9.4, 26.9 ± 4.8, respectively) than non-CDEs (11.1 ± 1.6, 29.2 ± 11.1, 22.4 ± 7.4, respectively). However, Knowledge means for both CDEs and non-CDEs were above the 85 percentile. Design and content scale responses showed that while dietitians provided basic information about safety and benefits related to exercise, they frequently reported “never” or only “sometimes” making exercise recommendations. ^ Although these results suggest that RDs are knowledgeable about exercise for older adults with Type 2 diabetes, greater importance should be made on training RDs to promote exercise, perhaps with an emphasis on a comprehensive team approach. ^

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In their article - Sales Promotion In Hotels: A British Perspective - by Francis Buttle, Lecturer, Department of Hotel, Restaurant, and Travel Administration, University of Massachusetts and Ini Akpabio, Property Manager, Trusthouse Forte, Britain, Buttle and Akpabio initially state: “Sales promotion in hotels is in its infancy. Other industries, particularly consumer goods manufacturing, have long recognized the contribution that sales promotion can make to the cost-effective achievement of marketing objectives. Sales promotion activities in hotels have remained largely uncharted. The authors define, identify and classify these hotel sales promotion activities to understand their function and form, and to highlight any scope for improvement.” The authors begin their discussion by attempting to define what the phrase sales promotion [SP] actually means. “The Institute of Sales Promotion regards sales promotions as “adding value, usually of a temporary nature, to a product or service in order to persuade the end user to purchase that particular brand as opposed to a competitive brand,” the authors offer. Williams, however, describes sales promotions more broadly as “short term tactical marketing tools which are used to achieve specific marketing objectives during a defined time period,” Buttle and Akpabio present with attribution. “The most significant difference between these two viewpoints is that Williams does not limit his definition to activities which are targeted at the consumer,” is their educated view. A lot of the discussion is centered on the differences in the collective marketing-promotional mix. “…it is not always easy to definitively categorize promotional activity,” Buttle and Akpabio say. “For example, in personal selling, a sales promotion such as a special bonus offer may be used to close the sale; an advertisement may be sales promotional in character in that it offers discounts.” Are promotion and marketing distinguishable as two separate entities? “…not only may there be conceptual confusion between components of the promotional mix, but there is sometimes a blurring of the boundaries between the elements of the marketing mix,” the authors suggest. “There are several reasons why SP is particularly suitable for use in hotels: seasonality, increasing competitiveness, asset characteristics, cost characteristics, increased use of channel intermediaries, new product launches, and deal proneness.” Buttle and Akpabio offer their insight on each of these segments. The authors also want you to know that SP customer applications are not the only game in town, SP trade applications are just as essential. Bonuses, enhanced commission rates, and vouchers are but a few examples of trade SP. The research for the article was compiled from several sources including, mail surveys, telephone surveys, personal interviews, trade magazines and newspapers; essentially in the U.K.

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The dissertation documented the degree of Turkey's involvement in the promotion of democracy in the Arab Middle East (ME). Initially, I investigated why and under what conditions Turkey promotes democracy in the ME, and then I explained strategies through which Turkey promotes democracy in the region. I applied the neo-classical realist theoretical framework and a mixed methodology in the research, and I provided evidence from two sources: face-to-face interviews with the Turkish and foreign officials and common citizens, and the statistical data from institutions, such as the OECD, Turkish Statistical Institute, and World Bank.^ My research indicates that Turkey promotes democracy through seven channels. These channels are official development assistance (ODA), mentoring, demonstrative effect, normative pressure, conditionality, military power, enlargement, and civil society organizations. Turkey promotes democracy in the ME for three substantial reasons: first, to advance its security and economic interests; second, to improve the political, social, and economic conditions of people living in the region; and third, to create long-term regional stability, crucial for cooperation in economic and security realms.^ I attempted to engage in debates with two distinct, but interrelated fields of comparative politics and international relations. My most important contribution to the field is that I documented Turkey's case of democracy promotion regarding the degree of Turkey's involvement in this endeavor, its strategies, specificities, and effectiveness in the region. I also contribute to the field as I explained the difference between democracy promotion policies of a regional power, such as Turkey, and global powers, such as the US. I further engaged in discussions that illuminate some aspects of the interplay between the identity and strategic interests in states' foreign policy decisions.^

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Peer reviewed

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Peer reviewed

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Introduction : Plusieurs études ont démontré que la pratique d’activité physique (AP) peut avoir un impact sur la vitalité cognitive des ainés. Le programme Musclez vos Méninges encourage les participants à être davantage actif et a été conçu pour promouvoir la vitalité cognitive. Ce mémoire vise à explorer : 1) les effets du programme sur l’AP; 2) l’effet modérateur et médiateur de l’AP sur les impacts du programme sur la cognition; 3) la corrélation entre l’AP et certaines dimensions cognitives des participants à l’entrée dans l’étude. Méthodologie: Au total, 294 personnes âgées de 60 ans et plus, intéressées à participer à un programme de vitalité cognitive ont été recrutées. Elles ont été évaluées avec des tests cognitifs (MoCA, MIA, CVLT, RBMT, MMQ, Attention, Stroop) et des instruments sur l’AP (une version adaptée du CHAMPS et le test de marche de 2 minutes du SFT). Des corrélations ont été faites à l’entrée dans l’étude et des régressions multivariées ont été réalisées pour mesurer l’impact du programme et celui de l’AP. Résultats : La participation au programme est associée à une hausse de l’AP (p< 0,05). Les analyses n’indiquent cependant pas d’effet significatif (p< 0,05) modérateur ou médiateur. À l'entrée dans l'étude, les sujets les plus actifs présentent de meilleurs résultats pour le recours aux stratégies mnésiques (p< 0,05). Conclusion: Un programme multifactoriel, incluant la promotion de l’AP, peut modifier significativement l’engagement à être physiquement actif. Des études futures devront toutefois démontrer si la pratique d’AP peut avoir un effet modérateur ou médiateur sur la vitalité cognitive.