On the solvability of the Birkhoff interpolation problem

AbstractA univariate Birkhoff interpolation problem is considered and the smallest N, namely N̄, for which the Birkhoff interpolation problem is always solvable is given. In particular, for Pólya matrices E with n ones we obtain N̄⩽n+p, where p is the number of odd supported sequences in E, and show that the preceding bound is the best possible

Impacts of Combined Sewer Overflows on surface water bodies. The case study of the Ebro River in Zaragoza city

Combined Sewer Overflows (CSOs) are the most important source of diffuse contamination in urban environments. Cleaner production in cities necessarily involves the reduction of both frequency and contamination linked to overflows in rain events as well as the control and minimization of its impacts in aquatic ecosystems. That would additionally lead to an increase in waste water treatment plant energy efficiency. However, there is an extended belief among sanitation managers at municipal level that impacts of CSOs in large rivers are not perceptible due to dilution effect. To dismantle this myth, the present article analyses the impacts of CSOs in the Spanish widest river, the Ebro River. The results suggest that the Ebro tends to worsen in dry season during intense rainfall, inviting to perform proper interventions to reduce CSOs along its urban stretch

LMI-based design of distributed energy-dissipation systems for vibration control of large multi-story structures

In this paper, we present an advanced computational procedure that allows obtaining distributed energy-dissipation systems for large multi-story structures. The proposed methodology is based on a decentralized velocity-feedback energy-to-componentwise-peak (ECWP) controller design approach and can be formulated as a linear matrix inequality (LMI) optimization problem with structure constraints. To demonstrate the effectiveness of the proposed design methodology, a passive damping system is computed for the seismic protection of a 20-story building equipped with a complete set of interstory viscous dampers. The high-performance characteristics of the obtained passive ECWP control system are clearly evidenced by the numerical simulation results. Also, the computational effectiveness of the proposed design procedure is confirmed by the low computation time of the associated LMI optimization problem.Peer ReviewedPostprint (published version

Note on an Inequality of N. G. de Bruijn

Abstract In this note an inequality of N. G. de Bruijn is used to obtain inequalities involving finite sums of sequences of real and complex numbers

Contribució a l'estudi de la micoflora de Catalunya : Cladosporium i Alternaria

Entre els treballs que pupliquem sobre fongs sapròfits aïllats a Catalunya, com a contribucio a la creacio d'un cataleg de la flora micològica catalana , incloem el present estudi referent als gèneres Alternaria i Cladosporium. Les espècies del gènere Cladosporium es troben àmpliament distribuïdes a la naturalesa , ja sia parasitant diverses plantes, ja sia corn a merament sapròfites al sòl o a I'aire, on, juntament amb el genere Alternaria, ocupen els primers llocs quant a freqüència. La taxonomia del gènere Alternaria és dificil, principalment a causa de la manca de caracteristiques notables. Les espores no són conidis, sinó tal·lòspores, i fins i tot en un mateix cultiu estan subjectes a àmplies variacions de grandària, format i nombre de septes . Quan els cultius són en medis diferents , s'hi troben diferències encara més grans; les espores tendeixen a ser més grosses en els medis rics que en els pobres, però s'hi produeixen amb menys llibertat. Per a llur classificacio hem fet servir les monografies de DE VRIES (1), ELLIS (2) i JOLY (4).On décrit des souches de diverses espèces saprophytes des genres Alternaria at Cladosporium que nous avons isolées dans nos travaux destinés à caractériser la flore mycologique de la Catalogne. On étudie les espèces suivantes : Alternaria radicine Meier , Drechsler et Eddy , A. tenuissima ( Fries) Wiltshire , A. consortiale (Thüm ) Hughes , A. chartarum Preuss , A. tenuis auctorum , A. saponariae (Peck ) Neergaard , Cladosporium avellaneum de Vries , C. cladosporioides ( Fres .) de Vries, C. cucumerinum Ell. at Arth ., C. herbarum Link ex Fr . C. macrocarpum Preuss, C. sphaerospermum Penzig et C. variabile ( Cke) de Vries

Cepas del género Penicillium aisladas en Cataluña

En el presente trabajo intentamos la clasificación de 133 cepas pertenecientes a 37 especies del género Penicillium Link, aisladas en Cataluña, así como la descripción macro y microscópica de todas ellas para su posible inclusión en un índice de la flora micológica de nuestro país

Understanding the discriminant factors that influence the adoption and use of clinical communities of practice : the ECOPIH case

The aim of the study presented in this article is to analyse the discriminant factors that have an influence on the use of communities of practice by primary and specialist healthcare professionals (physicians and nurses) for information sharing. Obtaining evidence from an ex-ante analysis to determine what factors explain healthcare professionals' clinical community of practice use allows aspects of its use to be identified. A theoretical model based on a modified technology acceptance model was used as the analysis tool, and a discriminant analysis was performed. An ad-hoc questionnaire was designed and sent to a study population of 357 professionals from the Badalona-Sant Adrià de Besòs Primary Care Service in Catalonia, Spain, which includes nine primary care centres and three specialist care centres. The study sample was formed by the 166 healthcare professionals who responded. The results revealed three main drivers for engagement in a CoP: First, for the whole sample, perceived usefulness for reducing costs associated with clinical practice was the factor with the greatest discriminant power that distinguished between users and non-users, followed by perceived usefulness for improving clinical practice quality, and lastly habitual social media website and application use. Turning to the two sub-samples of healthcare professions (physicians and nurses, respectively), we saw that the usefulness stemming from community of practice use changed. There were differences in the levels of motivation of healthcare professionals with regards to their engagement with CoP. While perceived usefulness for reducing costs associated with clinical practice was the main factor for the physicians, perceived usefulness of the Web 2.0 platform use for communication for improving clinical practice quality and perceived ease of use were the main factors for the nurses. In the context of communities of practice, the perception of usefulness of Web 2.0 platform use for communication is determined by organisational, technological and social factors. Specifically, the position that professionals have within the healthcare structure and particularly the closer healthcare professionals' activity is to patients and their professional experience of using social networks and ICTs are crucial to explaining the use of such platforms. Public policies promoting Web 2.0 platform use for communication should therefore go beyond the purely technological dimension and consider other professional and social determinants

Aplicabilidad del riego a pulsos en tablares

[ES] Se presentan ocho ensayos comparativos entre riego a pulsos y riego continuo en tablares, para variadas condiciones de parcelas y variables de riego. Se ha analizado el tiempo de aplicación para llegar al final de la parcela, la lámina infiltrada media, el coeficiente de uniformidad, y el perfil de agua infiltrada. Los resultados muestran que en la mayoría de los ensayos el riego continuo ha mejorado el riego a pulsos. Las condiciones en que el riego a pulsos ha resultado mejor son : Caudales unitarios bajos (1.5 l/s/m), aspereza o rugosidad hidráulica baja (n = 0.02) y suelo recién labrado. El factor controlador de la efectividad de los pulsos en riego por tablares parece ser el volumen superficial durante el avance; cuando este es grande, la efectividad disminuye.Monserrat, J.; Casali Sarasibar, J.; Tilló, J.; Cots I Rubió, L.; Barragán, J. (1997). Aplicabilidad del riego a pulsos en tablares. Ingeniería del Agua. 4(2):29-36. https://doi.org/10.4995/ia.1997.2720SWORD293642Allen, N. L. (1980). Advance Rates in Forrow Irrigation for Cycled Flow. Ph.D. diss. Utah State University, Logan.Blair, A.W. (1986) Surge flow irrigation infiltration. In Surge Flow Irrigation Field Guide. U.S.D.A.- S.C.S.Coolidge, P. S. (1981) Advance Rates Under Automated Pulsed Flow Irrigation System. Ph.D. diss. Utah State University, Logan.Camacho, E. (1993) Caracterización, optimización y manejo del riego por surcos mediante pulsaciones intermitentes. Tesis Doctoral. Universidad de Córdoba.Goldhamer, D.A., H.A. Mohammad and R.C. Phene (1987) Surge vs. continous-flow irrigation. California Agriculture, Sep-Oct: 29-32.Izuno, F.T., T.H. Podmore and H.R. Duke, (1985) Infiltration under surge irrigation. Transactions of ASAE 28 (2): 517-521.Monserrat, J., (1994). Solución al problema inverso del riego por tablares mediante un modelo hidrológico mixto. Tesis Doctoral. E.T.S.I.A., Universidad de Lleida.Podmore, T. H. and H. R. Duke, (1982). Field evaluation of Surge Flow Irrigation. Paper 82-2012. A.S.A.E, Madison, Wisconsin.Poole, G. J. (1981). Infiltration and Advance Under Surge Flow Irrigation. Ph.D. diss. Utah State University, Logan.Stringham, G. E.and J. Keller, (1979). Surge Flow Automatic Irrigation. Irrigation and Drainage Divi-sion Speciality Conference, A. S. C. E., Albuquerque, New Mexico.U.S.D.A - S.C.S. (1986). Surge Flow Irrigation Field Guide. 32 pp.Walker, W.R and G. V. Skogerboe, (1987). Surface irrigation: Theory and Practice. Prentice-Hall, INC, Englewood Clifs, New Yersey. 386 ppWestesen, G. L and D. K. Biglen, (1986). Surge flow border irrigation trials. A.S.A.E. paper n°: 86-2082