Estudio experimental del Sistema de Albañilería Integral en la construcción de viviendas sismorresistentes. Experimental study of the Integral Masonry System in the construction of earthquake resistant houses

This paper presents the application of the Integral Masonry System (IMS) to the construction of earthquake resistant houses and its experimental study. To verify the security of this new type of building in seismic areas of the third world two prototypes have been tested, one with adobe and the other with hollow brick. In both cases it’s a two-story 6x6x6 m3 house built to scale 1/2. The tests are carried out at the Laboratory of Antiseismic Structures of the Department of Engineering, Pontifical Catholic University of Peru in Lima, in collaboration with the UPM (Technical University of Madrid). This article shows the design process of the prototypes to test, including the sizing of the reinforcements, the characteristics of the tests and the results obtained. These results show that the IMS with adobe or brick remains stable with no significant cracks faced with a severe earthquake, with an estimated acceleration of 1.8 g. Este artículo presenta una aplicación del Sistema de Albañilería Integral (SAI) a la construcción de viviendas sismorresistentes y su estudio experimental. Para verificar su seguridad para su construcción en zonas sísmicas del tercer mundo se han ensayado dos prototipos, uno con adobe, y otro con ladrillo hueco. Se trata de una vivienda de 6x6x6 m3 y dos plantas que se construyen a escala 1/2. Los ensayos se realizaron en el Laboratorio de Estructuras Antisísmicas del Departamento de Ingeniería de la Pontificia Católica Universidad del Perú (PUCP) de Lima en colaboración con la UPM (Universidad Politécnica de Madrid). Este artículo muestra el proceso de diseño de los prototipos a ensayar, incluido el dimensionado de los refuerzos, las características de los ensayos y los resultados obtenidos. Estos resultados muestran que el SAI con adobe o ladrillo permanece estable sin grietas significativas ante un sismo severo, con una aceleración estimada de 1,8 g

A wireless instrumentation control system based on low-cost single board computer gateways

Nowadays, most of the automatized measurement processes are carried out by VISA (Virtual Instrument Software Architecture) compatible instruments, that execute the instructions provided by a host computer connected through wired standard buses, as USB (Universal Serial Bus), GPIB (General-Purpose Instrumentation Bus), PXI (PCI eXtensions for Instrumentation) or Ethernet. To overcome the intrinsic limitations associated to these wired systems, this work presents an instrumentation control system based on the IEEE 802.11 wireless communications standard. Intended for instruments having a USB control port, this port is connected to a gateway based on a compact Raspberry Single Board Computer (SBC) and thus the instrument can be connected to the host computer via Wireless Fidelity (WiFi), easily allowing the deployment of an ad-hoc instruments communication network in the working area or its connection to a previously deployed general purpose WiFi network. Developed under Python, the operation commands, wireless link protocol, and USB connection allow two modes of operation to provide system flexibility: a live mode, where commands are sent individually from the host computer to the selected instrument; and a standalone mode, where a full measurement process can be entirely downloaded in the gateway to be autonomously executed on the instrumentation. The system performance in both operation modes, distance of operation, time latencies, and operating lifetime in battery operation have been characterized

Optimización de láminas reticuladas de una capa

This article presents the reflection on optimum design in one layer lattice shells to cover large span spaces with different base geometries. The objective is to find parameters of form that have more effect on cost, in agreement with the Theory of Design of Structures (3,4), comparable to plane structures (4,12). To reach this aim, a program (8) has been created using Simulated Annealing (SA), a numerical approximation algorithm that finds solutions near optimum. The objective function used is extracted from the Theory of Design of Structures: structural volume. Its definition and characteristics will be seen. Diverse solutions to the numerical proposed examples are shown. These solutions solve similar problems changing the form of the plant to be covered. To finish, parameters of form from found solutions are displayed, and conclusions are extracted, such that SA is an appropriated method for this kind of problems.Este artículo muestra la reflexión sobre el diseño óptimo de laminas reticuladas de una sola capa en la cobertura de espacios de gran luz con diferentes bases. El objetivo es encontrar los parámetros que más efecto tienen en el coste de acuerdo con la Teoría de Diseño de Estructuras (3,4), de manera comparable a estructuras planas (4,12). Para alcanzar este propósito se ha creado un programa (8) que utiliza el Recocido Simulado (SA), una técnica de aproximación numérica que encuentra soluciones cercanas al óptimo. La función objetivo utilizada se extrae de la Teoría de Diseño de Estructuras: volumen estructural, se verán su definición y características. Se muestran diversas soluciones a los ejemplos numéricos propuestos; estas soluciones resuelven problemas similares cambiando la forma de la planta a cubrir. Para terminar se muestran los parámetros de forma obtenidos a partir del análisis de las soluciones, y se extraen conclusiones como que el SA es un método apropiado para esta clase de problemas

Madera en altura, estado del arte

This article is focused on analysing the current situation of timber high-rise construction. It begins with a historical review from the traditional Pagodas (up to 63 m tall) to visions of the future that rises to 350 m. It states the technical development that has led mass timber to today’s engineered products and its researches. It displays timber’s behaviour to fire and its properties as a structural material compared to others more commonly used in high-rise construction. It proves to be as mechanically competitive as concrete or high strength steel. Different strategies can be used against horizontal forces to obtain maximum slenderness. However, its main advantage, from an ecological point of view, is its capacity to absorb CO2, which, along its high degree of prefabrication, makes it a sustainable alternative with an increasing acceptance.El objetivo es mostrar el panorama actual de la edificación en altura con madera. Comienza con una revisión histórica desde las pagodas orientales (hasta 63m de altura) hasta las visiones de futuro (350m). Se muestra el desarrollo tecnológico que ha llevado la madera maciza hasta los productos industrializados actuales y las investigaciones en desarrollo. Se expone su comportamiento ante el fuego y las propiedades como material estructural en comparación con los materiales estructurales más utilizados para la edificación en altura: mecánicamente es tan competitivo como hormigones o aceros de alta resistencia. Ante acciones horizontales hay varias estrategias y se obtienen las esbelteces máximas alcanzables en altura. Su principal ventaja, desde el punto de vista ecológico, es su capacidad de absorber CO2, lo que, junto con el alto nivel de prefabricación, lo convierte en una alternativa sostenible cada vez con mayor aceptació

Microbial fuel cells: a green and alternative source for bioenergy production

Microbial fuel cell (MFC) represents one of the green technologies for the production of bioenergy. MFCs using microalgae produce bioenergy by converting solar energy into electrical energy as a function of metabolic and anabolic pathways of the cells. In the MFCs with bacteria, bioenergy is generated as a result of the organic substrate oxidation. MFCs have received high attention from researchers in the last years due to the simplicity of the process, the absence in toxic by-products, and low requirements for the algae growth. Many studies have been conducted on MFC and investigated the factors affecting the MFC performance. In the current chapter, the performance of MFC in producing bioenergy as well as the factors which influence the efficacy of MFCs is discussed. It appears that the main factors affecting MFC’s performance include bacterial and algae species, pH, temperature, salinity, substrate, mechanism of electron transfer in an anodic chamber, electrodes materials, surface area, and electron acceptor in a cathodic chamber. These factors are becoming more influential and might lead to overproduction of bioenergy when they are optimized using response surface methodology (RSM)

Sistema de autoconstrucción sismorresistente: características resistentes y proceso constructivo

The dwelling construction with soil, adobe or brick without call for technical advice is very typical in countries in process of development that are in areas of high seismic risk. To give an answer to the problem of earthquake building using these materials, providing simplicity of construction, we have worked for years in the use of the Integral Masonry System (IMS). The IMS is a system that, used combined with native materials, has earthquake resistant properties and its ease of implementation makes it suitable for self-build earthquake-resistant dwellings. This article describes the IMS, develops the constructive process applied to a type of two storey houses, and shows the seismic behaviour by means of the results obtained in the three test campaigns. The originality of the system lies in the use of a single type of prefabricated trusses, intertwined in the three spatial directions allowing create a dimensional mesh.La autoconstrucción con tierra, adobe o ladrillo es muy habitual en los países en vías de desarrollo que están en zonas de alto riesgo sísmico. Ante la necesidad de dar respuesta al problema, aportando sencillez constructiva, hemos trabajado desde hace años en el empleo del Sistema de Albañilería Integral (SAI). El SAI es un sistema que, combinado con materiales autóctonos, aporta resistencia sísmica y su facilidad de ejecución lo hace adecuado para la autoconstrucción de viviendas antisísmicas. Este artículo describe el SAI, desarrolla el proceso constructivo aplicado a una vivienda tipo de dos alturas y muestra su comportamiento sismo-resistente mediante los resultados obtenidos en tres campañas de ensayos. La originalidad del sistema radica en el empleo de un solo tipo de armaduras prefabricadas en forma de cercha que se entrelazan entre si en las tres direcciones del espacio permitiendo crear una malla tridimensional

Les Toxines des staphylocoques d’origine animale. Préparation et titrage de la Toxine ß

La toxine staphylococcique ß, caractéristique des souches d’ori gine animale, peut être obtenue en quantité importante en milieu liquide, mais est très généralement associée à des quantités varia bles de toxine u, ce qui entraîne des difficultés considérables dans les titrages. Parmi les méthodes permettant d’obtenir la toxine ß isolée, la floculation spécifique de la toxine a effectuée sur une toxine mixte a ß est la meilleure, le chauffage ou 1 action du formol entraînant une perte importante en toxine ß

Sur un Vaccin antistaphylococcique combiné : Anatoxines α et ß et Vaccin microbien polyvalent

Pillet J., Orta B., Isbir S., Mercier P., Lemétayer . Sur un vaccin anlislaphylococcique combiné : anatoxines α et β et vaccin microbien polyvalent. In: Bulletin de l'Académie Vétérinaire de France tome 103 n°7, 1950. pp. 409-412