Detailed Scale Model Research Articles

Lost roofs - case studies from Munich

The article presents the results of the author's research on lost roofs in Munich. Together with the buildings significant roof structures were destroyed in the Second World War. Munich always played a central role in Bavaria. The importance of the city grew continuously over the centuries. Talented master builders met demanding clients. This resulted in prestigious buildings that were also demanding in terms of construction technology. The study highlighted the most important objects. The aim was to reconstruct the destroyed roofs of these buildings on the basis of archival sources and building archaeological research on the remains. The results show a great variety, always reflecting the current developments in roof construction. Among them there are also quite experimental solutions. The results are presented as detailed scale models. The models allow to get a lasting impression of the lost structures. They serve to illustrate this essay. Finally, special attention is given to some constructions that have a link to italian designs.

Study of Gas Turbulent Dispersion Process in the Alcântara Launch Center

The Alcântara Launch Center (ALC) is the Brazilian gate to the space located at the north coast of Maranhao State,close to the Equator. Topographical local characteristics modify the parameters of incident atmospheric winds and it can cause great influence on the gas dispersion process. In this work, detailed scale models of the ALC region was experimentally evaluated using a wind tunnel. The topographical scale models were built where mean and fluctuating flow characteristics were analysed in order to understand the real behaviour of ALC winds and then, simulations of the effluent dispersion process were made using these scale models. The wind velocity was measured by a hot wire anemometer and the concentration fields in the proximities of a gas emission source were analysed by an aspirating probe connected to the anemometer system. The results obtained show similarity with numerical outputs from previous study in the case of the emission at ground level. A coherent behaviour with the physic of the phenomena was observed for the case of emission downward.

Groundwater flow model management and case studies in Emilia-Romagna (Italy)

The use of groundwater modeling to support the planning and management of water resources is a possible goal of a long and detailed course of study and research. The present work concerns some applications carried out within the aquifers of the Emilia-Romagna plain in northern Italy. The main features of the developed and available mathematical models are reported as well as the geological and hydrogeological description of the analyzed aquifers. The main operational choices that have characterized the implementation of all models and their continuous development and updating are discussed. Activity has been focused to maintain active the data stream between the models to improve their functionality along with time to give a basis for models management. Models have been used in different applications which indicate the potential for their use with targeted objectives of planning and management. Two examples at two different scales are given: the first shows the application to the entire aquifer of the Emilia-Romagna region, which has been able to adapt simulations to new groundwater bodies defined in accordance with 2000/60/EC directive, the current regulatory framework for the planning of water resources. This framework provides for the establishment of programs of measures whose level of effectiveness can be estimated with the support of models. The second concerns a more detailed scale model in reference to a specific evaluation of feasibility of an intervention of artificial recharge. The management approach used here is the result of over 10 years development and application and now allows to apply numerical models in a role of systematic service in support of the institutions involved in planning and management of groundwater resources.

An experimental study of turbulent flow over a low‐angle dune

Many large, sand bed alluvial channels are dominated by dunes that possess low‐angle lee sides, often <10°, which play a critical role in the transportation of sediment and generation of significant bed form roughness. Despite the fact that these low‐angle dunes are very common in such channels many current models of dune flow dynamics are based on bed forms with an angle of repose slip face that generates a zone of permanent separated flow in the dune lee. Study of flow associated with low‐angle dunes in the field is inherently difficult since it is usually both hard to measure very near the bed and hard to quantify the nature of turbulence over these bed forms. Results from a detailed scale model experimental study of flow over a low‐angle dune, which is based on a prototype dune from the Fraser River, Canada, present a necessary link between flume and field studies and document the origins of macroturbulence associated with these bed forms. Two‐dimensional laser Doppler anemometer measurements over a low‐angle dune (maximum lower lee side slope = 14°) show that dune morphology exerts a dominant control on the turbulent flow, causing flow deceleration in the lower lee and development of an intermittent layer of shear at the interface with the higher velocity flow above. The scale model confirms that permanent flow separation does not occur over low‐angle dunes but, instead, is replaced by a small region (here ∼7% of the dune wavelength in length) of intermittent flow reversal, which may be present for up to 4% of the time. Shear layers generated along this small zone of decelerated and/or separated flow in the lower lee have a much smaller velocity differential than is characteristic of shear layers generated by flow separation in the lee of angle of repose dunes. Turbulence production associated with low‐angle dunes is dominated by eddies generated along this shear layer, which produce highly variable horizontal and vertical velocities and large Reynolds stresses in this region. These results show that macroturbulence associated with low‐angle dunes is generated by intermittent separation or shear layer generation due to velocity gradients established in the zone of lee side flow expansion. Velocity profiles and maps of turbulence structure from the scale model are in reasonable agreement with field measurements from low‐angle dunes in natural sand bed rivers. These results highlight the need to consider the temporal evolution and intermittency of shear layer behavior, often very near the bed, when interpreting the generation of macroturbulence and dispersal of sediment associated with low‐angle dunes.

Architecture and Mathematics

It's got to have a center staircase!” “I've always wanted a kitchen with an island!” “Where is the best place for a skylight?” Enthusiastic comments such as these were typical of those I overheard while conducting a two-week workshop in which students used three-dimensional-model-building kits to plan and construct detailed scale models of their own home designs and to develop and sharpen mathematics skills related to architecture.

A negative staining-carbon film technique for studying viruses in the electron microscope: II. Application to adenovirus type 5

Two-dimensional and three-dimensional crystalline arrays of adenovirus type 5 were rapidly formed in vitro in the presence of negative stains when applied according to the negative staining-carbon procedure. The adenovirus capsids within the crystal lattice were packed predominantly in hexagonal arrays. Capsids were observed to be packed in positions viewed along axes of threefold symmetry and in other lattice arrays showed capsids in twofold symmetry positions. These crystalline arrays were extended over areas of several hundred microns across and provided ideal specimens for both optical diffraction and low-angle electron diffraction studies. When the adenovirus preparations were subjected to different negative staining and pH conditions, the capsids were observed to disrupt gradually at the specimen support surface. The released components were studied at high resolution and the structural components associated with the hexon and penton capsomeres were resolved. A detailed scale model of the adenovirus capsid was constructed from the information contained in the electron micrographs and the model used to illustrate the possible packing arrangements of the icosahedral capsid and penton fibres in the observed crystalline lattice.

The Musee des Plans-Reliefs

Anyone who has ever climbed the four steep flights of stairs to the long mansarded galleries just under the roof of the H6tel des Invalides must remember the impact of a first visit to the Musee des Plans-Reliefs. Despite poor lighting and the clutter resulting from inadequate display space, the superbly detailed scale models of forts and fortified cities constitute a unique and evocative historical exhibit. But it is probable that few visitors have realized that during the past several years only about half of the splendid collection has been available to the public, and it is entirely too likely that many who have come to see Napoleon's tomb and the fine Mus6e de l'Armde have missed the Plans-Reliefs altogether. Lack of appreciation for the enormous value of this collection is by no means unique in its troubled history, but at last there is hope that it will receive the attention and the facilities that it so richly merits. In the summer of 1968 the tercentenary of the Plans-Reliefs collection was celebrated, and the catalogue prepared for the occasion announced some very important joint decisions of the Ministry of Cultural Affairs and the Ministry of the Army, decisions which should result in expanded and improved display space and the reconstitution of the entire collection as a public exhibit. If nothing happens to frustrate the implementation of these welcome decisions, France's impressive historical treasures should be enriched still further in the near future.