Natural structures: strategies for geometric and morphological optimization

p. 893-906For centuries, architects and engineers have been searching the most efficient structural arrangements for their projects. Some of them have founded their proposals on the principle of biomimesis. The aim of their approach was to check how useful were 'for structural purposes' some geometrical patterns displayed by Nature on organic or inorganic bodies. Nature develops its structures in order to reach always optimal energetic solutions on a long term basis. The most usual arrangements are: pneus, shells, trees, webs and skeletons. All of them are controlled by four main factors: nature of forces, global form, local design and quality of material. Additional parameters, like pattern or material lightening, sometimes changes substantially the resulting geometry, and also some other general features as flexibility, integration, continuity, or self-straining are surrounding in most examples. This paper presents the achieved results on this topic by relevant authors of diverse fields: from the drawings of micro-organisms by the naturalist Häckel and the descriptive studies of the biologist Thompson, through the topological analysis of the patterns by the engineer Wester, the studies of natural lightweight structures by the architect F. Otto, to the final applications to light mega-structures by the engineers R. Le Ricolais or Buckminster Fuller.Pérez García, AJ.; Gómez Martínez, F. (2010). Natural structures: strategies for geometric and morphological optimization. Editorial Universitat Politècnica de València. http://hdl.handle.net/10251/695

Tensiones principales. Superposición de axiles, cortantes y flectores en régimen elástico lineal

En este artículo se ha analizado la distribución de tensiones generadas por múltiples solicitaciones (axil, cortantes en dos direcciones y momentos flectores actuando sobre dos ejes). Se considera que las solicitaciones provocan deformaciones en el rango elástico lineal y se trata de averiguar cuál sería la magnitud máxima que podrían alcanzar las cargas para que no se produzcan plastificaciones.Pérez García, AJ. (2013). Tensiones principales. Superposición de axiles, cortantes y flectores en régimen elástico lineal. http://hdl.handle.net/10251/3121

On the Sigma-invariants of even Artin groups of FC-type

In this paper we study Sigma-invariants of even Artin groups of FC-type, extending some known results for right-angled Artin groups. In particular, we define a condition that we call the strong n-link condition for a graph Gamma and prove that it gives a sufficient condition for a character chi : A(Gamma) -> Z to satisfy chi] is an element of Sigma(n)(A(Gamma), Z). This implies that the kernel A(Gamma)(chi) = ker chi is of type FPn. We prove the homotopical version of this result as well and discuss partial results on the converse. We also provide a general formula for the free part of H-n(A(Gamma)(chi); F) as an Ft(+/- 1)]-module with the natural action induced by chi. This gives a characterization of when H-n(A(Gamma)(chi); F) is a finite dimensional vector space over F

Even Artin Groups

Right-angled Artin groups form an interesting family of groups both from analgebraic and a topological point of view. There are a lot of well-known propertiesof right-angled Artin groups: for example they are poly-free, locallyindicable, right orderable and residually finite. Besides, also many importantproblems are well understood for these groups such as the word problem, therigidity problem, Serre's question or the K(pi, 1) conjecture.In this thesis, we will study some of these properties for a bigger andinteresting subfamily of Artin groups: even Artin groups. We generalizemany of these properties either for even Artin groups in full genarility or forsome big and interesting subfamilies.In particular, we prove that even Artin groups of FC type and large evenArtin groups are poly-free (which, as we will see, implies that they are alsolocally indicable and right orderable) and that even Artin groups of FC typeand general Artin groups based on trees are residually finite. Finally, weanswer Serre's question for the whole family of even Artin groups.<br /

Personalized rule-based closed-loop control algorithm for type 1 diabetes

Type 1 diabetes-mellitus implies a life-threatening absolute insulin deficiency. Artificial pancreas (CGM sensor, insulin pump and control algorithm) is promising to outperform current open-loop therapies

Conceptos básicos de estructuras y resistencia de materiales

En este documento se exponen una serie de conceptos básicos relacionados con las asignaturas de estructuras y resistencia de materiales utilizando una serie de imágenes inspiradas en el cuerpo humano con el fin de facilitar al alumno la comprensión de las mismas.Pérez García, AJ.; Guardiola Víllora, AP. (2013). Conceptos básicos de estructuras y resistencia de materiales. http://hdl.handle.net/10251/3121

The structural role played by masonry infills on RC building performances after the 2011 Lorca, Spain, earthquake

The final publication is available at Spriger via http://dx.doi.org/10.1007/s10518-013-9500-1On May 11, 2011 an earthquake of magnitude 5.1 (Mw) struck Murcia region causing nine casualties and damage to buildings and infrastructures. Even if the main characteristics of the event would classify it as a moderate earthquake, the maximum Peak Ground Acceleration (PGA) registered (equal to 0.37 g) exceeded significantly local code provisions in terms of hazard at the site. This high PGA was a result of directivity effects in the near source region. An overview of earthquake characteristics and damage observed is provided. Notwithstanding the lack of proper structural design characterizing building stock in the area, most of the losses were caused by non-structural damage. According to in field observations, it emerges that masonry infills provided additional, not designed , strength to reinforced concrete (RC) buildings. Observed damage data, collected after the earthquake, are shown and compared to the results of a simplified approach for nonstructural damage assessment of RC infilled structures (FAST vulnerability approach). The latter comparison provided a fair accordance between observed data and analytical results.The work presented has been developed in cooperation with Rete dei Laboratori Universitari di Ingegneria Sismica-ReLUIS-Linea 1.1.2. for the research program funded by the Dipartimento della Protezione Civile (2010-2013).De Luca, F.; Verderame, GM.; Gómez Martínez, F.; Pérez García, AJ. (2014). The structural role played by masonry infills on RC building performances after the 2011 Lorca, Spain, earthquake. 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Comisión permanente del hormigón estructural, Ministerio de Fomento, MadridEHE-08 (2008) Instrucción de hormigón estructural. Comisión permanente del hormigón estructural, Ministerio de Fomento, MadridEnomoto T, Schmitz M, Abeki N, Masaki K, Navarro M, Rocavado V, Sanchez A (2000) Seismic risk assessment using soil dynamics in Caracas, Venezuela. In: Proceedings of the 12th World Conference on earthquake engineering, Auckland, New ZelandErdik M, Durukal E, Siyahi B, Fahjan Y, Sesetyan K, Demircioglu M, Akman H (2004) Earthquake risk mitigation in Istanbul, Chap 7. In: Mulargia F, Geller RJ (eds) Earthquake science and seismic risk reduction. Kluwer, DordrechtFajfar P (1999) Capacity spectrum method based on inelastic demand spectra. Earthq Eng Struct Dyn 28:979–993Fardis MN (1997) Experimental and numerical investigations on the seismic response of RC infilled frames and recommendations for code provisions. Report ECOEST-PREC8 No 6. 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Cálculo de celosías planas de nudos articulados con el método de Ritter

En este documento se explica el método de Ritter o de los cortes para obtener los axiles en las barras de las celosías planas estáticamente determinadas.Pérez García, AJ.; Guardiola Víllora, AP. (2013). Cálculo de celosías planas de nudos articulados con el método de Ritter. http://hdl.handle.net/10251/3057

Design of linearly polarized parallel plate slot antennas

The authors propose a design method for calculating the position and length of the slots in a linearly polarized parallel plate slot antenna for 12 GHz. The beam is tilted 5” in order to improve the reflection coefficient and to reduce the grating lobes level. The antenna is filled with a dielectric of low constant, to reduce the total cost of the antenna. The feeding system is a resonant slotted waveguide placed at the bottom of the parallel plate

Degradation and in-use stability study of five marketed therapeutic monoclonal antibodies by generic weak cation exchange liquid chromatographic method ((WCX)HPLC/DAD)

Therapeutic monoclonal antibodies (mAbs) represent a very important class of the current biopharmaceutics. The great complexity of their structure made necessary the use of different analytical approaches for assessing different physico-chemical properties. In this work, weak cation exchange (WCX) high performance liquid chromatography with diode array detection ((WCX)HPLC/DAD) is used to assess the charge variant profile. The method here developed combined the effect of ionic strength and controlled pH gradient and allows for the charge variants analysis of the five mAbs studied, namely bevacizumab (BVZ), cetuximab (CTX) infliximab (INF), rituximab (RTX) and trastuzumab (TTZ), which are among the most used mAbs worldwide. The differences in the charge variants in the natural isoforms of the mAbs promoted characteristic WCX chromatograms for each of mAbs that can be also useful for identification purposes. These chromatograms have provided to be suitable for tracking changes in the charge variants of each mAb analyzed both in controlled degraded and in stabilities study along time of in-use samples solutions at 2 mg/mL in 0.9% NaCl stored refrigerated (at 4 ?C) and frozen (-20 ?C) for two months. The results obtained indicated different stabilities of these mAbs, all IgG1, against degradation by different stressed environmental conditions and in-use stability along two months.Instituto Carlos III, Ministerio de Economia y Competitividad, Spain FIS-PI10/00201 FIS-PI17/00547European Commission Junta de Andalucia European Commissio