Ciment natural a Catalunya : història, producció i usos

La tesi que estic realitzant es pot dividir en tres grans blocs. En aquest article, exposaré el que de moment tinc fet del primer bloc i unes pinzellades dels altres dos. La primera part, i la que està més avançada, és la que inclou un estudi de recerca, tant documental com de camp, i una anàlisi exhaustiva de la producció i en general, dels diferents usos del ciment natural a Catalunya des dels seus inicis, a mitjans del S. XIX, fins a finalitzar-se'n l'ús generalitzat, quan pren relleu amb força el ciment pòrtland artificial, a mitjans del S. XX. Es dóna molta importància a conèixer l'evolució que es va produir pel que fa a la presència dels diferents conglomerants amb base calç; la calç aèria, les hidràuliques, i els diferents tipus de ciments que es fabricaven, així com la seva coexistència. Els altres dos blocs són experimentals; un inclou la metodologia emprada per a la identificació del tipus de conglomerant usat a partir de morters històrics, així com els resultats de multitud de mostres recollides de diferents tipus d'edificis i elements constructius. El tercer i últim apartat consisteix en la caracterització dels ciments naturals que es fabriquen en l'actualitat a Catalunya

Una diagnosi prèvia a qualsevol intervenció

Si no es fa prèviament a la intervenció una diagnosi de l’estat de conservació o de degradació de la peça, ni cap estudi dels materials emprats per l’artista i evidentment tampoc un estudi cromàtic de com era originalment, de les textures, o de qualsevol altre tret que caracteritza i fa única l’escultura, és del tot probable errar en la restauració de l’obra. En definitiva, uns treballs previs amb un diagnòstic que aportin la informació necessària, no només per intervenir el més respectuosament possible l’obra sinó també per mantenir l’esperit i la idea original de l’artista.Peer ReviewedPostprint (published version

Use of wastes to create new building materials

This paper is a teaching activity carried out on the subject of Building Materials from Building Engineering studies. This subject is developed in the second year and lasts for a four month period. The student teacher ratio is around 60:1. The goal of this work was the development of a new building material obtained from waste materials. Students were divided in teams of three students chosen by themselves. This activity helped students to develop knowledge about different materials and make them aware of the importance and possibilities to profit waste materials. Students should work with materials studied in the subject, mainly clay, glass, steel, wood and plastics. Before beginning they must do an important bibliographic research about the topic they wanted to develop. The university provided the use of lab facilities and the guidance of the teacher. Besides following up the work, the teacher encouraged the students to perform some tests on the new material obtained. Finally they should come out with a poster and a sample of the material. Results got from different works differed substantially according to the interest and time dedicated to them. Most of the students abused of the use of polymeric resins to elaborate the new materials, and therefore, even using wastes the new materials were not so sustainable. The use of natural materials such as cane fibres leaded to materials with interesting insulation and structural properties. It was a very good experience to attract students to materials research. Finally we discovered in order to get profitable results, this kind of activity should cover a longer period and should count with the continuous guidance of the teachers.Postprint (published version

El Forn de raig

Recuperación y puesta en valor de un horno tradicional para producción de calPeer Reviewe

Classification of symmetric periodic trajectories in ellipsoidal billiards

We classify nonsingular symmetric periodic trajectories (SPTs) of billiards inside ellipsoids of R^{n+1} without any symmetry of revolution. SPTs are defined as periodic trajectories passing through some symmetry set. We prove that there are exactly 2^{2n}(2^{n+1}-1) classes of such trajectories. We have implemented an algorithm to find minimal SPTs of each of the 12 classes in the 2D case (R^2) and each of the 112 classes in the 3D case (R^3). They have periods 3, 4 or 6 in the 2D case; and 4, 5, 6, 8 or 10 in the 3D case. We display a selection of 3D minimal SPTs. Some of them have properties that cannot take place in the 2D case.Comment: 26 pages, 77 figures, 17 table

CEDECAP: Desarrollando las capacidades en gestión de sistemas energéticos aislados en la zona andina

Gran parte de los proyectos de electrificación rura l usando energías renovables que se han instalado en las últimas décadas han colapsado o se encuentran en un estado precario debido a la ausencia de una apropiada y completa capacitación de los campesinos o usuarios de las comunidades locales. El Perú está sumido en un proceso de renovación y cambios a nivel de gobierno tanto en el terreno político como en el legislativo. El nuevo gobierno tiene el reto y la ambición de culminar el proceso de descentralización y la voluntad de priorizar la electrificación rural. La nueva ley de electrificac ión rural y su marco regulatorio están en proceso de discusión para su aprobación en un breve espacio de tiempo. El reglamento es sensible al fomento de la capacitación tanto de los usuarios como de los operadores, así como de promover otros modelos de gestión, que se constituyan en aspectos claves para el impulso adecuado y definitivo de la electrificación rural mediante sistemas aislados co n energías renovables. En el presente artículo, se presenta al CEDECAP (Centro de Demostración y Capacitación en Tecnologías Apropiadas) por una parte como alternativa a las tradicionales capacitaciones que se han ido realizando en los últimos años en los proyectos de instalación de sistemas de energías renovables en las zonas rurales y por otra como una oportunidad para dar soporte y promoción a las políticas de electrificación rural dictadas tanto d esde el gobierno peruano como de las instituciones internacionales de referencia. Dos aspectos se identifican como diferenciadores y a la vez pertinentes en el contexto anteriormente mencionado: 1. El aspecto de la sostenibilidad de los sistemas tanto a nivel técnico como social es un punto transversal en todas las capacitaciones del CEDECAP. Como se ha dicho anteriormente, promover modelos de gestión creativos pero viables, es una parte en la que tradicionalmente no se ha dado mucha importancia pero que ahora se incluye en las currículas del CEDECAP como parte fundamental del diseño de los proyectos. 2. La vocación de que el CEDECAP se convierta en un centro de referencia en energías renovables para la Zona Andina que fomente la transferencia de conocimiento Sur-Sur y Sur-Sur-Norte de las tecnologías apropiadas y especialmente de las energías renovables. Se trata de un centro físico, itinerante y virtual donde se puede recurrir fácilmente para consultar o asistir a cursos y en el cuál se va a recopilar todo el conocimiento y experiencia en capacitación y energías renovables. Finalmente se presenta como ejemplo la capacitación en gestión de sistemas fotovoltaicos que ha realizado el equipo de CEDECAP en la zona de Orellana (selva amazónica de Ecuador).Peer ReviewedPostprint (published version

La intervenció en l'obra artística

Josep Maria Subirachas fou un experimentador amb materials molt lligats a l'arquitectura i la construcció.Peer ReviewedPostprint (published version

Photodynamic therapy of cutaneous T-cell lymphoma cell lines mediated by 5-aminolevulinic acid and derivatives

The delta-amino acid 5-aminolevulinic acid (ALA), is the precursor of the endogenous photosensitiser Protoporphyrin IX (PpIX), and is currently approved for Photodynamic Therapy (PDT) of certain superficial cancers. However, ALA-PDT is not very effective in diseases in which T-cells play a significant role. Cutaneous T-cell lymphomas (CTCL) is a group of non-Hodgkin malignant diseases, which includes mycosis fungoides (MF) and Sézary syndrome (SS). In previous work, we have designed new ALA esters synthesised by three-component Passerini reactions, and some of them showed higher performance as compared to ALA. This work aimed to determine the efficacy as pro-photosensitisers of five new ALA esters of 2-hydroxy-N-arylacetamides (1f, 1 g, 1 h, 1i and 1 k) of higher lipophilicity than ALA in Myla cells of MF and HuT-78 cells of SS. We have also tested its effectiveness against ALA and the already marketed ALA methyl ester (Me-ALA) and ALA hexyl ester (He-ALA). Both cell Myla and SS cells were effectively and equally photoinactivated by ALA-PDT. Besides, the concentration of ALA required to induce half the maximal porphyrin synthesis was 209 μM for Myla and 169 μM for HuT-78 cells. As a criterion of efficacy, we calculated the concentration of the ALA derivatives necessary to induce half the plateau porphyrin values obtained from ALA. These values were achieved at concentrations 4 and 12 times lower compared to ALA, according to the derivative used. For He-ALA, concentrations were 24 to 25 times lower than required for ALA for inducing comparable porphyrin synthesis in both CTCL cells. The light doses for inducing 50% of cell death (LD50) for He-ALA, 1f, 1 g, 1 h and 1i were around 18 and 25 J/cm2 for Myla and HuT-78 cells respectively, after exposure to 0.05 mM concentrations of the compounds. On the other hand, the LD50s for the compound 1 k were 40 and 57 J/cm2 for Myla and HuT-78, respectively. In contrast, 0.05 mM of ALA and Me-ALA did not provoke photokilling since the concentration employed was far below the porphyrin saturation point for these compounds. Our results suggest the potential use of ALA derivatives for topical application in PDT treatment of MF and extracorporeal PDT for the depletion of activated T-cells in SS

Tomographic findings and mortality in patients with severe and critical pneumonia with COVID-19 diagnosis

Introduction: A high percentage of patients with non-severe (17.9%) and severe (2.9%) atypical pneumonia do not display pulmonary tomographic findings upon hospital admission; furthermore, lesion associated with COVI-19 are peripherally distributed in a multifocal ground-glass pattern, as well as displaying an irregular consolidation pattern, with a posterior or lower lobe predilection. The main objective of this study was to identify the pulmonary radiological patterns in patients diagnosed with SARS-CoV-2 pneumonia, the factors associated with the need for mechanical ventilation, as well as their survival rates at 30 days. Methods: We report the pulmonary tomographic findings of 490 consecutive patients with severe and critical pneumonia due to SARS-CoV-2. The patients were classified according to the tomography and demographic findings, sepsis severity prognostic scales, Charlson comorbidity index (CCI), the Sequential Organ Failure Assessment (SOFA), and the Acute Physiology and Chronic Health Evaluation (APACHE IV). The Kaplan-Meier method was used to calculate survival distributions. Results: 89.80% of patients had ground-glass opacities, 81.63% radiologic consolidation sign, 42.45% vascular thickening pattern, 37.55% lymphadenopathies, 14.90% pleural effusion, and 2.65% pulmonary thrombosis; meanwhile, 91.02% had bilateral lesions, 85.51% had peripheral lesions, and 75.92% had basal lobe lesions. APACHE IV (HR, 1.191, 95% CI [1.126, 1.260]), SOFA (HR, 5.178, 95%CI [3.103, 8.641]), and CCI (HR, 0.673, 95%CI [0.510, 0.889]), as well as the pulmonary damage severity index (HR, 1.282, 95%CI [1.151, 1.428]), predict the need for invasive mechanical ventilation. Only moderate ARDS patients with mild and severe lung disease showed different 30-day mortality distributions (χ2 = 7.00, p = 0.008). Discussion: Although the survival distributions did not vary significantly, an overwhelming majority of patients (i.e., 84.35%) with a higher pulmonary damage severity index (i.e., 23>) died within 30 days of hospital admission, while only 25.91% with moderate lung damage and 2.42% with mild lung damage

etrological, geochemical (major, trace, and rare earth elements), and U–Pb zircon data of the Tamatán Group, NE Mexico

From samples of the Paleozoic Tamatán Group (Huizachal–Peregrina Anticlinorium, Tamaulipas, Mexico), petrographic (qualitative and modal) and geochemical analyses (major, trace, and rare earth elements) were conducted. The first U–Pb geochronological data on detrital zircons of the Tamatán Group were generated using four samples. The data presented here contains a broad overview of photomicrography, recalculated modal point-count data, raw geochemical data, and simple statistics of selected geochemical parameters. The data presented in this article are interpreted and discussed in the research article titled “Provenance and tectonic setting of the Tamatán Paleozoic sequence, NE Mexico: Implications for the closure of the Rheic Ocean at the northwestern part of Gondwana”publishedVersio