Two-dimensional (2-D) peat microtopographical model

Matlab script file of a two-dimensional (2-D) peat microtopographical model together with other supplementary files that are required to run the model.

Treatment of singularities in 2-D domains using BIEM

The singularities which arise when there is a sudden change of boundary conditions are modelled using spectral shape interpolation functions. The procedure can be used for elasticity as well as potential theory and to any degree of accuracy with respect to the smooth part of the curve.

SERBA: a B.I.E. program with linear elements for 2-D elastostatics analysis

The great developments that have occurred during the last few years in the finite element method and its applications has kept hidden other options for computation. The boundary integral element method now appears as a valid alternative and, in certain cases, has significant advantages. This method deals only with the boundary of the domain, while the F.E.M. analyses the whole domain. This has the following advantages: the dimensions of the problem to be studied are reduced by one, consequently simplifying the system of equations and preparation of input data. It is also possible to analyse infinite domains without discretization errors. These simplifications have the drawbacks of having to solve a full and non-symmetric matrix and some difficulties are incurred in the imposition of boundary conditions when complicated variations of the function over the boundary are assumed. In this paper a practical treatment of these problems, in particular boundary conditions imposition, has been carried out using the computer program shown below. Program SERBA solves general elastostatics problems in 2-dimensional continua using the boundary integral equation method. The boundary of the domain is discretized by line or elements over which the functions are assumed to vary linearly. Data (stresses and/or displacements) are introduced in the local co-ordinate system (element co-ordinates). Resulting stresses are obtained in local co-ordinates and displacements in a general system. The program has been written in Fortran ASCII and implemented on a 1108 Univac Computer. For 100 elements the core requirements are about 40 Kwords. Also available is a Fortran IV version (3 segments)implemented on a 21 MX Hewlett-Packard computer,using 15 Kwords.

Kinematic analysis of a novel 2-d.o.f. orientation device

This paper presents the development of a new parallel robot designed for helping with bone milling surgeries. The robot is a small modular wrist with 2 active degrees of freedom, and it is proposed to be used as an orientation device located at the end of a robotic arm designed for bone milling processes. A generic kinematic geometry is proposed for this device. This first article shows the developments on the workspace optimization and the analysis of the force field required to complete a reconstruction of the inferior jawbone. The singularities of the mechanism are analyzed, and the actuator selection is justified with the torque requirements and the study of the force space. The results obtained by the simulations allow building a first prototype using linear motors. Bone milling experiment video is shown as additional material.

An efficient nonlinear transformation for the numerical computation of the singular integrals appearing in the 2-D Boundary Element Method

We discuss several methods, based on coordinate transformations, for the evaluation of singular and quasisingular integrals in the direct Boundary Element Method. An intrinsec error of some of these methods is detected. Two new transformations are suggested which improve on those currently available.

Cálculo de estructuras continuas: V. 1. Métodos generales : estructuras 1-D y 2-D

Estas notas, que se publican en dos volúmenes, surgen como resultado de las clases de doctorado que, durante el curso académico 1979-80, impartió Avelino Samartín en la Escuela Técnica Superior de Ingenieros de Caminos, Canales y Puertos de la Universidad de Santander. El objetivo del curso era ambicioso ya que se intentaban presentar, de un modo panorámico, los distintos procedimientos analíticos y semianalíticos de Cálculo de Estructuras así como su aplicación al análisis efectivo de diferentes casos prácticos: vigas, placas y láminas. La publicación que se presenta es el volumen uno, que corresponde a la primera parte del curso, referente a los métodos generales de cálculo y su aplicación a casos sencillos : estructuras 1-D y 2-D. También se incluye, en el capítulo 5, una combinación natural de elementos 2-D - laja y placa-, correspondiente a la lámina plegada. Se deja para un segundo volumen el estudio de otras estructuras laminares específicas, así como la introducción a la teoría general de láminas. A lo largo del curso -y en estas notas se refleja- se ha intentado mostrar la identidad de la metodología existente en todo el cálculo estructural , desde la estructura más simple -columna- a la más compleja -lámina-, tanto en su planteamiento como en su resolución. Con esta publicación se desea -aparte de cubrir un evidente vacío bibliográfico, en nuestra lengua, sobre el tema- impulsar el uso de los diferentes métodos analíticos que actualmente existen y que, por causas bien conocidas - facilidad de computación - han sido, en opinión de los autores, inmerecidamente relegados al olvido, cuando podrían, muchas veces, sustituir , o al menos complementar, otras técnicas numéricas más potentes.

Analysis, reliability and optimization of reinforced concrete 2-D structures

In this paper a consistent analysis of reinforced concrete (RC) two-dimensional (2-D) structures,namely slab structures subjected to in-plane and out-plane forces, is presented. By using this method of analysis the well established methodology for dimensioning and verifying RC sections of beam structures is extended to 2-D structures. The validity of the proposed analysis results is checked by comparing them with some published experimental test results. Several examples show some of these proposed analysis features, such as the influence of the reinforcement layout on the service and ultimate behavior of a slab structure and the non straightforward problem of the optimal dimension at a slab point subjected to several loading cases. Also, in these examples, the method applications to design situations as multiple steel families and non orthogonal reinforcement layout are commented.

Regional subsidence modelling in Murcia city (SE Spain) using 1-D vertical finite element analysis and 2-D interpolation of ground surface displacements

Subsidence is a hazard that may have natural or anthropogenic origin causing important economic losses. The area of Murcia city (SE Spain) has been affected by subsidence due to groundwater overexploitation since the year 1992. The main observed historical piezometric level declines occurred in the periods 1982–1984, 1992–1995 and 2004–2008 and showed a close correlation with the temporal evolution of ground displacements. Since 2008, the pressure recovery in the aquifer has led to an uplift of the ground surface that has been detected by the extensometers. In the present work an elastic hydro-mechanical finite element code has been used to compute the subsidence time series for 24 geotechnical boreholes, prescribing the measured groundwater table evolution. The achieved results have been compared with the displacements estimated through an advanced DInSAR technique and measured by the extensometers. These spatio-temporal comparisons have showed that, in spite of the limited geomechanical data available, the model has turned out to satisfactorily reproduce the subsidence phenomenon affecting Murcia City. The model will allow the prediction of future induced deformations and the consequences of any piezometric level variation in the study area.

Queensland, Australia, 1896 (Image 1 of 2) (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: Queensland and British New Guinea : prepared for educational purposes, Survey Deptartment, Brisbane. It was published by The Dept. in 1896. Scale [ca. 1:1,710,720]. This layer is image 1 of 2 total images of the two sheet source map, representing north portion of the map. Covers primarily northeast Australia and a portion of Papua New Guinea.The image inside the map neatline is georeferenced to the surface of the earth and fit to the Geocentric Datum of Australia 1994 Map Grid of Australia Zone 54 projected coordinate system. All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as roads, railroads and stations, drainage, coastal features, selected places of interest, administrative boundaries, and more. Relief shown by shading and spot heights. This layer is part of a selection of digitally scanned and georeferenced historic maps from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of originators, ground condition dates, scales, and map purposes.

Queensland, Australia, 1896 (Image 2 of 2) (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: Queensland and British New Guinea : prepared for educational purposes, Survey Deptartment, Brisbane. It was published by The Dept. in 1896. Scale [ca. 1:1,710,720]. This layer is image 2 of 2 total images of the two sheet source map, representing south portion of the map. Covers primarily northeast Australia and a portion of Papua New Guinea.The image inside the map neatline is georeferenced to the surface of the earth and fit to the Geocentric Datum of Australia 1994 Map Grid of Australia Zone 54 projected coordinate system. All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as roads, railroads and stations, drainage, coastal features, selected places of interest, administrative boundaries, and more. Relief shown by shading and spot heights. This layer is part of a selection of digitally scanned and georeferenced historic maps from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of originators, ground condition dates, scales, and map purposes.

Dijon, France, 1761 (Image 1 of 2) (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: Plan géométral de la ville de Dijon : levé en 1759 par les ordres de M.M. les Elus Généraux de Bourgogne, et de M.M. les Maire et Echevins de la dite ville par le Sr. Mikel, Ingenieur Géographe du Roy ; et les vue et ornemens, dessinés par le Sr. Jolivet, Architecte... ; gravé à Paris par Jean Lattré. It was published by Jean Lattré, rue St. Jacques à la ville de Bordeaux in 1761. Scale [ca. 1:2,800]. Covers Dijon, France. This layer is image 1 of 2 total images of the two sheet source map, representing the southwest portion of the map. Map in French. The image inside the map neatline is georeferenced to the surface of the earth and fit to the European Datum 1950, Universal Transverse Mercator (UTM) Zone 31N projected coordinate system. All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as roads, drainage, built-up areas and selected buildings, fortification, parks, cemeteries, ground cover, and more. Includes illustrations.This layer is part of a selection of digitally scanned and georeferenced historic maps from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of originators, ground condition dates, scales, and map purposes.

Dijon, France, 1761 (Image 2 of 2) (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: Plan géométral de la ville de Dijon : levé en 1759 par les ordres de M.M. les Elus Généraux de Bourgogne, et de M.M. les Maire et Echevins de la dite ville par le Sr. Mikel, Ingenieur Géographe du Roy ; et les vue et ornemens, dessinés par le Sr. Jolivet, Architecte... ; gravé à Paris par Jean Lattré. It was published by Jean Lattré, rue St. Jacques à la ville de Bordeaux in 1761. Scale [ca. 1:2,800]. Covers Dijon, France. This layer is image 2 of 2 total images of the two sheet source map, representing the northeast portion of the map. Map in French. The image inside the map neatline is georeferenced to the surface of the earth and fit to the European Datum 1950, Universal Transverse Mercator (UTM) Zone 31N projected coordinate system. All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as roads, drainage, built-up areas and selected buildings, fortification, parks, cemeteries, ground cover, and more. Includes illustrations.This layer is part of a selection of digitally scanned and georeferenced historic maps from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of originators, ground condition dates, scales, and map purposes.

Europe & Mediterranean Sea Region, 1705 (Image 1 of 2) (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: Toonneel des oorlogs in't zuider deel van Europa, door Carel Allard = Theatre de la guerre dans l'Europe meridionale, par Charles Allard. It was published by C. Allard in 1705. Scale [ca. 1:6,800,000]. Covers a portion of Europe and the Mediterranean Sea region. This layer is image 1 of 2 total images of the two sheet source map, representing the western portion of the map. Map in Dutch and French. The image inside the map neatline is georeferenced to the surface of the earth and fit to the World Miller Cylindrical projected coordinate system. All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as drainage, cities and other human settlements, territorial boundaries, shoreline features, and more. Relief shown pictorially.This layer is part of a selection of digitally scanned and georeferenced historic maps from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of originators, ground condition dates, scales, and map purposes.

Europe & Mediterranean Sea Region, 1705 (Image 2 of 2) (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: Toonneel des oorlogs in't zuider deel van Europa, door Carel Allard = Theatre de la guerre dans l'Europe meridionale, par Charles Allard. It was published by C. Allard in 1705. Scale [ca. 1:6,800,000]. Covers a portion of Europe and the Mediterranean Sea region. This layer is image 2 of 2 total images of the two sheet source map, representing the eastern portion of the map. Map in Dutch and French. The image inside the map neatline is georeferenced to the surface of the earth and fit to the World Miller Cylindrical projected coordinate system. All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as drainage, cities and other human settlements, territorial boundaries, shoreline features, and more. Relief shown pictorially.This layer is part of a selection of digitally scanned and georeferenced historic maps from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of originators, ground condition dates, scales, and map purposes.

India & South Asia, 1828 (Image 1 of 2) (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: Map of India : exhibiting its present political divisions, with a supplement containing the Birman Empire, Pickett sculpt. It was published by Chas. Smith, No. 172 Strand in 1828. Scale [ca. 1:4,950,000]. This layer is image 1 of 2 total images of the two sheet source map, representing the northern portion of the map. Covers India, Bangladesh, Nepal, Bhutan, Sri Lanka, and portions of Afghanistan, Pakistan, China, and Maldives. The image inside the map neatline is georeferenced to the surface of the earth and fit to the Kalianpur 1975 India Zone III projected coordinate system. All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as drainage, cities and other human settlements, territorial and administrative boundaries, roads, shoreline features, and more. Relief shown by hachures. Includes also an inset of Burma.This layer is part of a selection of digitally scanned and georeferenced historic maps from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of originators, ground condition dates, scales, and map purposes.