José Luis Muñoz Sanz

Development of Personalized Annuloplasty Rings: Combination of CT Images and CAD-CAM Tools

Although the use of personalized annuloplasty rings manufactured for each patient according to the size and morphology of their valve complex could be beneficial for the treatment of mitral insufficiency, this possibility has been limited for reasons of timelines and costs as well as for design and manufacturing difficulties, as has been the case with other personalized implant and prosthetic developments. However, the present quality of medical image capture equipment together with the benefits to be had from computer-aided design and manufacturing technologies (CAD-CAM) and the capabilities furnished by rapid prototyping technologies, present new opportunities for a personalized response to the development of implants and prostheses, the social impact of which could turn out to be highly positive. This paper sets out a personalized development of an annuloplasty ring based on the combined use of information from medical imaging, from CAD-CAM design programs and prototype manufacture using rapid prototyping technologies.

Analysis of different multiaxial fatigue criteria in the prediction of pitting failure in spur gears

The aim of this article is to study the appearance of pitting in spur gears by taking account of different multiaxial fatigue criteria. The stress levels undergone by the teeth are considered in order to be able to predict their life and compare the fatigue strength of gear materials. The process begins calculating the stress field inside the teeth flanks due to the pressure and shear stress in the contact along the mesh. Once the stresses are known, the appearance of failure is studied by using different multiaxial fatigue criteria: Dang Van, Crossland and Liu-Mahadevan criteria. The accuracy of each criterion to predict pitting in gears is analysed using experimental data.

The Machine Renaissance

The Renaissance in Western Europe in the fourteenth to sixteenth centuries marked strong activity of recovery and revitalisation in artistic, scientific, and literature frames that overcame the stagnation of the Middle Ages. Unlike during medieval times, the opening of society during the Renaissance promoted the spread of machines in many environments. Little by little, many existing machines were no longer considered simply as a means of carrying out civil or military engineering works.

Medieval Machines and Mechanisms

In medieval times the most creative mechanical developments took place in the Islamic world. Some of those engineering and technological achievements are little-known due to the fact that, at that time, knowledge passed from master to apprentice through direct experience without being recorded in any written form. In addition, few manuscripts were actually written and only a few of them have survived through time.

Industrial Archaeology: From the 17th to the 21st Century. Reconstruction of Herschel’s Telescope

Towards the end of 1997, the director of the National Astronomical Observatory, Jesus Gomez, commissioned the Machines and Mechanisms Laboratory of this School, to produce a viability study for the reconstruction of “Herschel’s Great Telescope”. This device was built in the 18th century as part of the fine set of instruments that on the orders of Charles IV, were to equip the Madrid Royal Observatory, which had been created by Charles III in 1790. Unfortunately, this great telescope was destroyed in the War of Independence. All that survived were a few remains, and the image of its structure, thanks to the magnificent illustrations executed by the hand of Mendoza (Fig. 1), the naval officer to whom the King had entrusted its construction.

The Evolution and Development of Mechanical Engineering through large cultural areas

Mechanical Engineering is probably the forerunner of many branches of Engineering and has persistently been their companion up to the present. For this reason, the History of Machines embraces a very broad period of the History of Mankind, and can be studied from many perspectives. This paper attempts to link progress in Mechanical Engineering to the great cultures that have arisen throughout the History of Mankind.

Machinery During the Industrial Revolution

To attempt to cover machine developments during the Industrial Revolution in just few pages is as absurd as it is impossible. This period of our history arose after the knowledge of previous eras had been accumulated and through a combination of a series of factors that resulted in a period of continuous advances and progress that ended up in a change of approach both in society and engineering, with technical developments of huge quantity.

The Twenty-One Books of Devices and Machines: An Encyclopedia of Machines and Mechanisms of the 16th Century

Progress in Engineering and Architecture has been decisive in the birth and duration of empires throughout History, and Mechanical Engineering has always played an important role. For long periods of the 16th and 17th centuries the Spanish Crown became the World’s leading political and economic power, so extensive that in the domains of King Philip II, “the Sun never set”.

Mechanical Engineering in Antiquity

Like since the first man appeared on the face of the Earth, in Antiquity help was sought to overcome human physical limitations and to make the hard and most difficult tasks easier. In Antiquity, slaves were forced to carry out the most arduous tasks, but solutions were also contemplated in the form of machines or simple devices that would have replaced slaves or would have assisted them in several kinds of work. This machine design practice and activity established the first technical culture of independent competition and professional fields.

A Vision on Machines

In the western world, the practice of machine construction and the theory of mechanics came together at the end of the Renaissance with two lines of development: treatises in the form of rationally classified machine collections and machine studies as an application of mechanical physics.