Gotowa bibliografia na temat „Roofers in modesto”

This paper presents and compares the methods of implementing and promoting Blue-Green Infrastructure in the urban landscape of European cities and around the world. Selected areas are located in the centre of cities such as: Kronsberg in Hanover, Germany; Bishan-Ang Mo Kio Park, Singapore; green roofs and green streets in Portland, USA; Copenhagen, Denmark; and Mumbai, India. The paper also cites more modest examples of the implementation of Blue-Green Infrastructure in Polish cities such as Wrocław, Szczecin, Kraków and Gdańsk. Amidst the diversity of climatic zones in which the public spaces in question are located, in the context of a strong need for sustainability, these areas share a common problem of climate change.

In this paper, a typology of a building erected in Ancient Greece and Ancient Rome is described: the Odeon. The Odeon is a covered building, but more modest in size than traditional open-air theatres without roofs. The Odeon could hold a few hundred spectators and therefore a smaller audience. The roof covering allowed the possibility of meetings even in adverse weather conditions. The etymology of the word of the Odeon (covered theatre) means the place of the ode, or of the songs. In this paper are discussed the architectonic and acoustic characteristics of the Odea of Pompeii and Posillipo. With commercial software (Odeon, Room Acoustics Software, Lyngby Denmark) we assess the acoustic characteristics of the Odea of Pompeii and Posillipo in the presence of an original roofing system and show that these buildings were well suited for music, songs and speech.

In Brazil, the adoption of sustainable urban drainage (SUD) measures is modest, and the conventional approach prevails. This research evaluates the perception of 377 professionals (civil engineers, environmental engineers and architects) that work in João Pessoa and surroundings regarding their knowledge on SUD, their preferences and barriers for adopting SUD. Most of them demonstrate limited knowledge on the subject, with difficulty distinguishing between conventional and sustainable measures. But the vast majority of professionals were willing to adopt SUD facilities in their projects, preferably infiltration trenches, permeable pavements and green roofs. The maintenance of the devices and the hirer/user acceptance were key aspects for this choice, while superiors’ disinterest, the unfamiliarity of entrepreneurs and financiers, and lack of governmental support were the primary barriers. There is a need to improve the academic education of these professionals and provide basic understanding of SUD principles for several other actors. Keywords: Stormwater. Green infrastructure. Low impact development. Source-control.

The life of Henry Styleman le Strange illustrates a number of significant factors in the development of the Tractarian Movement and its relationship with the arts. He was a devout layman who wished to advance the practice of Tractarian worship and spirituality. He did this by encouraging Tractarian worship in the churches on his estates and by appointing Tractarian clergy to livings of which he was patron. He was himself a distinguished amateur artist and architect, who was modesdy influential in the nineteenth-century ideal for exploring the interrelationship between the self-dedication of the artist to moral and religious truth, and Christian art. This can be seen in his own artistic work, in the tower and nave roofs at Ely Cathedral, and his collaborations with other architects, notably Butterfield. As important as his own work is his influence as a patron, not merely in restoring churches on his estate or in the development of a seaside resort, but in the pattern that emerges of his friends and acquaintances also commissioning his favoured architect.

Photovoltaic Systems (PV) are the most widely used renewable energy source in the Republic of Croatia but with a modest share in the total energy balance. EU energy policy encourages PV installation in building elements such as facades, roofs or separate constructions with the aim of achieving zero-energy buildings. Whether an integrated or stand-alone system during their lifetime requires periodic maintenance. In a normal operation, it is necessary to carry out a visual inspection twice a year before and after the winter period to determine the condition of the equipment, connecting lines and supporting structures. In the case of a significant deviation from the normal production, the inspection must be done as soon as possible. Most commonly, the problems of the unmaintained system cannot be perceived as long as the PV system is in an operational state. Dropping of dust, bird droppings or shading over a longer period may lead to system components being damaged and to necessary repair costs that can be prevented by regular maintenance procedures, including regular surface cleaning of photovoltaic panels. Infrared thermography is a fast method of detecting heat sources due to shading or defective photovoltaic module elements. The paper provides visual examples of thermal spots that can be observed during the infrared thermographic inspection of photovoltaic systems, as well as a review of their impact on the system.

This study investigates how permeable and cool pavements, green roofs, and living walls affect microclimatic conditions and buildings’ energy consumption in an arid urban setting: Shiraz. The study aims to evaluate the role of green infrastructure in mitigating urban heat island effects and enhancing outdoor conditions. By utilizing environmental modeling tools, specifically the ENVI-met 5.1.1 and Design Builder 7.0.2 software, a comprehensive analysis was conducted across various scenarios during both the summer and winter seasons. The results show that permeable pavements with 80% grass coverage reduced the mean average air temperature by 1.18 °C in summer mornings compared to the reference case. In both the summer and winter scenarios, the living wall intervention consistently emerged as the most effective strategy, showcasing substantial reductions in cooling consumption, CO2 emissions, and electricity consumption. With a 25% reduction in cooling consumption, a 14.7% decrease in CO2 emissions, and an impressive 53.4% decline in electricity consumption, the living wall excelled in its environmental impact, and it stands out for its substantial electricity savings. While the green roof and permeable pavement scenarios demonstrated more modest gains, their integration could offer a synergistic solution, warranting further exploration for optimized energy efficiency and environmental sustainability. These findings indicate the intrinsic connection between sustainable landscaping strategies and their influence on urban microclimate and building energy efficiency.

As per the current estimates, nearly half of the world’s population lives in the cities, by 2030 it is calculated to increase to 70%. This calls for a need of more sustainable structure in the urban areas as to support increase in the urban population. Urban Heat Island is one such conspicuous phenomenon which has its significance at local regional and also at the global levels. It is a microscale temperature variation between urban and rural areas, in which urban area are warmer compare to surrounding rural area. The temperature difference between the urban and the rural areas are usually modest, averaging less than 1°C, but occasionally rising to several degrees when urban, topographical and meteorological conditions are favorable for the UHI to develop. It is defined as the phenomena where in the occurrence of surface and atmospheric modifications due to the urbanization causes modification in the thermal climatic conditions which results into warmer areas as compared to the surrounding non urbanized areas, particularly in night. In that case urban built forms such as buildings, roofs, pavements etc. absorb more solar heat/radiation and remain warmer throughout the day time and slowly release energy during night time. The two major causes are rapid urbanization and anthropogenic heat generated due to transport and industrial activities. Urban Heat Island is a crucial subject for global environment. Urbanization has significant effects on local weather and climate. Among these effects one of the most popular is the urban heat island, for which the temperatures of the central urban locations are several degrees higher than those of nearby rural areas of similar elevation. Satellite data provides important inputs for estimating regional surface albedo and evapo-transpiration required in the studies related to surface energy balance. <br><br> The phenomenon of UHI affects environment and population in so many ways it can also be considered as an active element that cause vulnerabilities to human health, the marginal population affected largely as the natural environment is their only home or their main shelter. Furthermore elderly people also affected in greater amount as their weakening immunes system. Major effects of UHI on environment include: a) Air Quality, b) Energy consumption and c) Human health. <br><br> To study the causes and effect of UHI of any urban area, the first step is to demarcate the spatial distribution of UHI and its intensity over different time period of the day as well as difference in the temperature of urban area with the surrounding rural areas. Secondly, study of land use land cover change in the area also helps in identifying causes of heat accumulation for particular region. After marking up of intensity, analysis of different zones for understanding the relationship between UHI and urban morphological features can be done which further became suggestive towards planning of urban center that mitigates the effect of UHI. Mainly two approaches are there to demarcate UHI study as: <br><br> &ndash; Field data collection and observations <br> &ndash; Remote sensing data analysis <br><br> For a long period of time observations from interior of the city and outwards of it can analyze by a climatic methods, by observing many days as well as many times of a day continuously to analyze the daily variation law of the heat island effects. As the city is for its developmental approaches may cover an area of hundreds of square kilometers, the ground observation data is not able to provide enough detail about the urban heat island distribution characteristics. The most precise method is the Satellite Remote Sensing method. The UHI phenomenon can be analyzed by using the thermal infrared data obtained meteorological satellite sensing. The atmospheric attenuation can be corrected for the remote sensing data by use of meteorological soundings and ground observation data. Ideally the heat island effect over a city is not same for any other city. <br><br> Satellite images from AVHRR Advanced Very High Resolution Radiometer) or ENVISAT AATSR provides thermal infrared data and comparatively easy to acquire, process and analyze. In the case of Ahmedabad city, land cover changes over the time is to be studied by classifying the image and then temperature can be derived by using a quadratic regression model from Malaret at al. (1985). Band 6 produces the images that show the relative difference emitted thermal energy that correlate in part with the effects of solar heating on surface of varying composition and orientation. The surface temperatures are suitable to detect UHI at Urban canopy level. Nichol (1996) found that surface temperatures extracted are moreover similar to the actual ambient air temperatures recorded. <br><br> The paper has narrated analylitical framework on which the research has been carried out. The result derived on Land Surface Temperature variation causing Urban Heat Island, its relationship with the land use land cover. A time series data has been used. Authors are thankful to Ms. Darshana Rawal, Ms. Pallavi Knahdewal and Mr. Hardik Panchal.

Caricin Grad, Justiniana Prima, urban planning, fortification, settlement, aerial photography, geophysical surveys, LiDAR, photogrammetry, excavations, GIS. Thanks to the application of modern non-destructive sensing and detection methods, in recent years a series of new data on urban planning in Caricin Grad was obtained. For the most part, the current research programme studies the Upper Town?s northern plateau, wooded until recently and hence the only previously unexplored unit of the city. In the course of this programme, the classical research method - the excavations started in 2009 - is for the first time combined with the systematic application of airborne and terrestrial sensing and detection techniques. The analysis of historic aerial photographs and topographic plans proved to be very useful as well. Along with them, LiDAR-derived DTMs, photogrammetric DEMs, different geophysical and orthophotographic plans are stored in the GIS database for Caricin Grad and the Leskovac Basin. In this way almost 80 percent of the plateau area was defined, and the obtained plan is hypothetical only to a small extent, which particularly refers to the unexcavated northern rampart of the Upper Town. Each source provided relevant information for the reconstruction of both the rampart and the settlement, which points to the value of a holistic approach to documentation from various dates. The first source to be studied were archival aerial photographs of Caricin Grad from 1938 and 1947 (Figs. 1, 2.1). The latter one was originally processed by Aleksandar Deroko and Svetozar Radojci}, who drew the plan of the town after it, labelling the unexplored Upper Town?s northern plateau as ?a probable habitation area?. The route of the northern rampart was aslo rather precisely determined by the authors (Fig. 2.2). Recently, these photographs were rectified and georeferenced in the GIS. The 1938 shot reveals the position of some towers as well, and it is also indicative of the way of construction of certain buildings. From the spatial layout of whitish zones, originating from mortar scattered along the slope, it can be deduced which buildings were constructed in opus mixtum - the horreum and the so-called Building with Pillars east of it. Traces of mortar can be observed along the route of the rampart too. These archival images are particularly important because they record the topography of the site before it was filled with heaps of earth from the excavations. The topographic mappings of this area were conducted in 1981 and 2006 (Fig. 3). The first plan was drawn after an airborne stereophotogrammetric survey of Caricin Grad, and in 2006, after the wood was cut down, this whole area was surveyed with the total station, with a density of nine points per square meter. This survey also resulted in a 3D terrain model (Fig. 3.2) indicating the layout of the buildings, which was to be proved by geophysical surveys and archaeological excavations. In the course of the Serbian-French reaearch programme, in 2007 geomagnetic surveys were carried out by Alain Kermorvan of the University of Tours. Thanks to the application of this method the remains of collapsed stone structures could be observed, and in 2015, in cooperation with the Roman-Germanic Central Museum, Mainz, and the Ludwig Boltzmann Institute from Vienna, the middle and eastern parts of the plateau were scanned with GPR (Fig. 4.2). Precise plans of the buildings were obtained in the areas in which LiDAR scanning and photogrammetric and geomagnetic surveys failed to produce clear images. Within the framework of the ArchaeoLandscapes Europe project, in 2011 we managed to organise an airborne LiDAR survey of the wider area of Caricin Grad. With its density of some 20 points per square meter, this scanning proved to be crucial for our comprehension of the town. The standard DTM provided numerous important data, especially its version calculated in the focal statistics function of the ArcGIS software package (Fig. 5. 1-2). These models show not only the route of the Upper Town?s northern rampart, the position of its towers and the layout of the buildings, but also the line of the Outer Town?s western rampart. Visible only in the DTM, this entirely new aspect of the Caricin Grad fortification has been attested by the excavations. Highly important plans of the town, and of the northern plateau of the Upper Town in particular, were obtained by UAV photogrammetric surveys. The first drone survey was conducted in 2014 within the scope of the same project. It resulted in a cloud with up to 1,600 points per square meter (Fig. 6.1-2). Unlike the LiDAR technology, photogrammetry cannot penetrate vegetation; therefore the preliminary clearing of the ground proved to be a most important step. After the 2015 campaign was finished, the excavation area in the Upper Town was documented again in the same manner. Regular photogrammetric surveys make possible the control of the works and reliable visual monitoring of the progress of exploration (Fig. 9). After the wood was cut down in 2006 and enormous heaps of earth from twentieth-century excavations and restoration works were carefully removed by machinery in 2008 and 2010, without disturbing the original layers of debris, wide excavations could begin. At first only the humus layer was removed from fifteen-meter squares, which was followed by technical drawing. In 2009 and 2010 we did not explore the debris or the cultural layers (Fig. 7.1-2). The additional two squares were opened and documented in the same fashion in 2011, when previously recorded buildings 11 and 15C were explored in detail, together with the part of the corridor between them where a bread oven was found. These buildings were oriented south-north, cascading along the mild slope towards the northern rampart of the Upper Town. Fragments of pithoi and carbonised fruits were found in the buildings, allowing for an economic interpretation. Judging by coinfinds, the buildings ended in fire after the year 602. Some of the buildings on the northern plateau were oriented differently, following the route of the northern rampart of the Acropolis in the east-west direction. In 2012 building 18 was excavated, leaning on the rampart. Rectangular in plan and some 12 by 7.5 meters large, it had a storey and a 7 by 5.5 meters spacious paved atrium in the west. Parallel to building 18 is building 20, the only one on the northern plateau constructed in opus mixtum. The two buildings are separated by a four-meter-wide street, running from east to west. This street, corridor 4, was partly cut in the rock. In some sections it had a substructure of fragmented debris. Building 20 has been carefully excavated for several years now. After the initial documenting, the surface layer of debris was removed, but not the collapsed structures with characteristic construction details; to the east of the building a collapsed wall was uncovered, containing as many as eight successive rows of stone and brick. Beneath these layers are the occupation ones, so far investigated only to a small extent. Building 20 is rectangular in plan, covering 25 by 12.5 meters. In its central axis there is a row of masonry pillars, dividing the building into two naves. On its western side there was a vestibule with a pair of doors matching the main entrances to the building. In the back of the vestibule, between these entrances and in axis with the pillars, there was a staircase. Adetailed analysis of these features led us to conclude that building 20 was a horreum, the first such edifice to be discovered in Caricin Grad. Taking into account the details of its ground plan, pillars, parts of collapsed walls and especially arches, it will be possible to reconstruct the original form of the horreum. Judging by the existing estimate, although somewhat rough, it was 13.5 meters high. It could be observed that in its later phases the horreum was partitioned into several rooms, and some of its entrances were walled up. In the vestibule only these later occupation phases were documented, as the original brick pavement was removed from its northern part. This was followed by a significant accumulation of cultural layers, which were sealed by the debris stratum. South of the horreum there is a spacious courtyard connected with the western street of the Upper Town. The Upper Town?s northern rampart has never been graphically reconstructed, despite the fact that Aleksandar Deroko and Svetozar Radojci} published its accurate (although schematic) ground plan as early as 1950 (Fig. 2.2). This part of the town has gradually been left out of the research focus, mainly due to the vegetation growth. Upon employing all the methods described above, however, it is possible to undertake such an effort. The ideal reconstruction suggested here includes the rampart route, the disposition and the form of the towers, and the possible locations of the posterns. The line of the rampart can be traced following the trenches left by the locals dismantling the walls. Only the section of the northwestern rampart in front of the western postern of the Acropolis cannot be presented, being still covered by massive earth deposits. On the other hand, the recently discovered western rampart of the Outer Town can be traced to its full length in the LiDAR-derived DTM. Its form can be easily reconstructed on the basis of the results of the 2012 excavations and the section of the same rampart uncovered east of the main fortifications in 1955-56 (Fig. 8). Having studied the microtopography of the terrain, we were able to determine the position of a number of towers. They were clearly indicated by bumps, regularly distributed along the northern and northeastern sections of the rampart. The position of the tower below the Acropolis? western postern could be easily determined as well, unlike the position of the tower opposite to the horseshoe-shaped one of the Acropolis fortification. Yet, it is hard to imagine that a hundred-meter-long section of the rampart was left unprotected. The rectangular shape of the towers is suggested because almost all the towers of the town?s outer fortification were constructed in that way. On the other hand, at present we cannot exclude the possibility that some towers were different, horseshoe-shaped in plan, like the ones on the Acropolis rampart. The disposition of the towers along the northeastern rampart of the Upper Town, in the area where the northern street presumably met the fortification, is not clear. This part of the site still lies under massive heaps of earth, and even the 1938 and 1947 aerial photographs are not indicative enough in this regard. However, the tower(s) might have been erected there, not only because the eighty-meter-long stretch of the rampart would be left without protection in an opposite scenario, but because it is likely that the northern street ended in a gate, or at least a postern. It is already known that some of the posterns on the Caric in Grad fortifications were defended by towers. The average distance between the towers of the town?s main fortification extends from 20 meters on the southern to 40 meters on the western rampart of the Lower Town; in our reconstruction the average interval on the Upper Town?s northern rampart is 44 meters. Another argument is that this gate might have connected the Upper and the Outer Towns. The position of the second postern is determined thanks to a depression in the terrain following the axis of another communication route in the Upper Town, leading from corridor 4 and running towards the north along the rows of buildings. Finally, the 3.8 meter width of the rampart in the section adjoining the northern tower of the Upper Town?s eastern gate may only indicate a staircase, the last reconstructed fortification element. On the plateau stretching between the northern ramparts of the Acropolis and the Upper Town fortifications a settlement developed with its radially distributed rows of buildings cascading down the slope. In the eastern part of the plateau there is the horreum, adjoined from the east by another building - the storage called Building with Pillars. Larger than the other buildings and constructed in opus mixtum, the two buildings follow the route of the Upper Town?s northern street, all of which indicates that they belong to the initial construction phase. One should not exclude the possibility that this part of the town was originally conceived as an economic district with storages and similar edifices. By all appearances, the original concept was soon abandoned. Already at the time of Justinian a settlement of numerous smaller buildings was created. With their walls of stone and wattle and daub, the buildings were roofed with tiles. Yet one should underscore that this construction phase, although less sophisticated than the first one, was accomplished according to a previously prepared plan; the spread of the buildings speaks to that effect. Shortly afterwards, if not at the same time, buildings were erected along the outer face of the Acropolis rampart - a clear indication of abandoning urban planning (Fig. 9). Public space was turned into private, in spite of the legal proscriptions of that time. During the last phase of the town?s life the buildings described, whether public or private, were partitioned into small rooms, often with fireplaces and with some of their entrances walled up. Just like the edifices constructed in opus mixtum, some of the more modest buildings from the second construction phase were used to store food - namely buildings 11 and 15C. The plan of this part of the site points to an organised settlement, most probably inhabited by persons servicing a significant clergy and administration. On the other hand, except for some houses - such as building 18 - small buildings along the Acropolis fortification, facing the main street, corridor 4, might have served as shops and workshops. Traces of furnaces, slag and bone working were also encountered in this area. The parallel application of classical research methods and modern techniques of sensing and detection enabled the reconstruction of the northern rampart and the urban matrix of the Upper Town?s northern plateau. Until recently among the least known parts of the town, this unit can now be regarded as one of the best defined. This is important not only for our understanding of Caricin Grad (Justiniana Prima), but also for the study of Early Byzantine urban planning in general.

The roof plays a pivotal role as it directly engages with solar radiation absorption and external heat exchange, significantly influencing the building’s overall energy dynamics. To assess the performance of green roofs and cool roofs, a roof performance test facility was established in Nanjing. Time-difference comparison experiments were conducted to measure and analyze the energy-saving effects of cool roofs, green roofs, and conventional roofs during both summer and winter conditions. The study aimed to investigate how their thermal performance impacts building energy consumption. The study’s findings reveal that under summer conditions, the incorporation of a cool roof system leads to a substantial enhancement in energy efficiency, achieving an impressive 13.2% energy savings compared to conventional roofing solutions. In contrast, the implementation of a green roof system results in a more modest energy-saving rate of 4.1%. Transitioning to winter conditions, the adoption of a cool roof system shows a marginal increase of 2.8% in energy consumption compared to conventional roofs. Interestingly, the green roof system stands out as an energy-efficient option during winter, demonstrating a significant 4.9% reduction in energy consumption. This approach ensured reliable and valid results to provide a comprehensive view of how different roof types respond to varying climatic conditions.

The global adoption of whirly bird vent roofs across various industries underscores their utility in harnessing wind energy for cooling purposes within warehouses and similar environments. The innovation proposed in the current study builds upon this established technology by integrating semi-perpetual motion principles into a compact twin whirly bird-inspired wind turbine design. This novel approach aims to enhance power generation efficiency, thereby offering a sustainable solution for energy production. The compact twin whirly bird turbine concept represents a significant advancement, particularly in the context of powering electric vehicle (EV) chargers. As the demand for EVs continues to surge, concerns persist regarding the availability of charging infrastructure. By integrating the proposed innovative wind turbine technology into the EV charging ecosystem, we address this critical issue while simultaneously promoting the adoption of renewable energy sources. The key to our proposal is the deployment of small-scale wind turbines in diverse public locations, thereby democratizing access to clean energy generation. Unlike conventional large-scale wind turbines, our whirly bird-inspired turbines boast versatility in installation, akin to streetlamps, facilitating widespread deployment across urban landscapes. While these turbines may yield comparatively modest power outputs relative to megawatt-scale counterparts, their strategic placement ensures a decentralized network capable of powering EV charging stations. In summary, our research presents a compelling solution that bridges the gap between EV charging infrastructure availability and the utilization of renewable energy sources. By leveraging the inherent advantages of whirly bird-inspired wind turbines, we offer a practical pathway towards sustainable energy provision in public spaces, thereby facilitating the widespread adoption of electric vehicles.

As estruturas de membrana empregadas em coberturas são sistemas construtivos formados principalmente pela membrana estrutural, que ainda tem a função de vedar. As membranas estruturais são folhas flexíveis que resistem às ações externas devido à sua forma, às suas características físicas e ao seu pré tracionamento. O pré-tracionamento da membrana pode ser alcançado, ou através do seu estiramento por meio de cabos (estruturas de membrana protendida por cabos), ou através da atuação da pressão de gases (estruturas pneumáticas). Ambas estão sendo usadas em coberturas de centros esportivos, de áreas comerciais e de construções industriais ou agro-industriais. Todavia, as estruturas de membrana são pouco conhecidas, estudadas e empregadas no Brasil. Neste contexto, este trabalho tem como objetivos sistematizar o conhecimento científico existente sobre o tema e introduzi-lo no Brasil e, também, apontar caminhos para investigação científica sobre as estruturas de membrana no país. Apresenta o sistema construtivo, o processo de projetar e os métodos de análise das estruturas de membrana empregadas em coberturas. Sistematiza o projeto de estruturas de membrana, através de recomendações e de estudo de caso. Propõe um modelo de pesquisa integrado voltado para o desenvolvimento desta tecnologia no Brasil. Este deve auxiliar a coordenação e a compatibilização dos esforços de investigação científica nas diversas áreas do conhecimento envolvidas no desenvolvimento das estruturas de membrana
Membrane structures used in roofs are constructive systems formed mainly by structural membrane, which has also the function of sealing. Structural membranes are flexible sheets that resist to external loads due to their form, to their physical characteristics and to their pre-stressing. The pre-stressing of the membrane can be achieved either through its stretching using cables (surface-tensioned membranes) or through gases pressurization (pneumatic structures). These structures are being utilized in roofs over airports, stadiums, industrial facilities, shopping precincts and buildings for industrial or agricultural use, among others. However, membrane structures are not yet well known, studied and used here in Brazil. In this context, this work has as objectives to systematize the scientific knowledge existent on the theme, to introduce it in Brazil and, also, to point out ways for scientific investigation on membrane structures in this country. This research presents the constructive system, the design process and the analysis methods of membrane structures used in roofs. This work systematizes the membrane structural design, with recommendations and study of case. This work proposes an integrated model of research for this technology development in Brazil. This model should assist the coordination and the mutual appreciation of the scientific investigation efforts in the different knowledge areas involved in the membrane structure development

Abstract A Foreigner visiting London in the last years of the eleventh century, though impressed by its spaciousness and the magnitude of its population, found the only thing that called for remark was the phenomenal number of savage dogs that lurked about St. Paul’s at night-time to the terror of the passers-by. This, however, scarcely does justice to the city which had long since attained to a position of pre-eminence in the kingdom. In 1135 it was described as the metropolis and queen of the whole kingdom; its citizens were, like those of the Cinque Ports, ‘barons’. It had been surrounded by a wall since Roman times, and it was now approached by seven gates. Besides the White Tower, two other strongholds were already standing, both on the western side, the castle of Montfichet and Baynard’s castle whose lords commanded the military forces of the city and controlled the Thames fishing as far as Staines bridge. Still its pretensions were modest; its houses were unsubstantial structures, mostly of wood and thatched with straw. Fire and tempest wrought havoc in such conditions. William of Malmes-bury gives a vivid description of a south-easterly gale in 1091 that destroyed 600 houses in London: churches were heaped upon houses; roofs, rafters, and beams hurtled through the air. Another catastrophe occurred in the first year of Stephen’s reign: a fire starting from London Bridge swept through the city, demolishing St. Paul’s and most of the rickety dwellings as far as St. Clement Danes, some distance to the west and outside the wall.

The floating roofs are widely used to prevent evaporation of content in large oil storage tanks. The 2003 Tokachi-Oki earthquake caused severe damage to the floating roofs due to liquid sloshing. The structural integrity of the floating roofs for the sloshing is urgent issue to establish in the petrochemical and oil refining industries. This paper presents the sloshing characteristics of the single deck floating roofs in cylindrical storage tanks. The hydrodynamic coupling of fluid and floating roof is taken into consideration in the axisymmetric finite element analysis. It is assumed that the fluid is incompressible and inviscid, and the floating roof is linear elastic while the sidewall and the bottom are rigid. The basic vibration characteristics, natural periods and vibration modes, of the floating roof due to the sloshing are investigated. These will give engineers important information on the floating roof design.

The floating roofs are widely used to prevent evaporation of content in large aboveground oil storage tanks. The 2003 Tokachi-Oki earthquake caused severe damage to the floating roofs due to liquid sloshing. The structural integrity of the floating roofs for the sloshing is urgent issue to establish in petrochemical and oil refining industries. This paper presents the axisymmetric finite element analysis for the sloshing response of floating roofs in cylindrical storage tanks. The hydrodynamic coupling of fluid and floating roof under seismic excitation is taken into consideration in the analysis. It is assumed that the fluid is incompressible and inviscid, and the roof is linear elastic while the sidewall and the bottom are rigid. The theory for the finite element analysis in which the behavior of the fluid is formulated in terms of dynamic pressure as the Eulerian approach is developed. The basic vibration characteristics of the floating roof, such as natural periods and vibration modes, can be obtained from this analysis. These will give engineers important information on the floating roof design.

Floating roofs are widely used to prevent evaporation of contents of large cylindrical oil storage tanks. The 2003 Tokachi-Oki earthquake caused severe damage to floating roofs due to liquid sloshing. Seven single-deck floating roofs deformed to leak oil on them, and they lost buoyancy to sink. Two of them were the single-deck type with center pontoon in large diameter tanks. The present paper deals with an axisymmetric finite element analysis for the sloshing response of a floating roof with center pontoon. The hydrodynamic coupling of the fluid and the floating roof under seismic excitation is taken into consideration in the analysis. The fluid is assumed to be incompressible and inviscid, and the roof is assumed to be linear elastic. In addition, the sidewall and the bottom are assumed to be rigid. In the finite element analysis, the behavior of the fluid is formulated in terms of dynamic pressure using the Eulerian approach. The basic vibration characteristics of the single-deck floating roof with center pontoon, such as the natural periods and vibration modes, can be obtained from this analysis. These characteristics are shown comparing with those of the single-deck floating roof without center pontoon. The seismic response analysis for the input of an earthquake wave is also performed.

Seismic qualification of the large oil tanks requires consideration of a lot of specific failure modes. One of them is the failure induced by dynamic behaviour of the floating roofs or pontoons: a collision between floating steel roof and tank wall during an earthquake can lead to the post crash fire with severe system fault. Seismic behaviour of a 50000 m3 tank with floating pontoon has been investigated in a numeric study. Seismic safety limits of the considered tank including floating roof movement are presented. A validation study using numerical experiments of the tank with floating pontoon has been performed in order to verify the analytical approach. An influence of the tank anchorage on the tank seismic behaviour and specific failure modes connected with tank bottom uplift has been also investigated.

Roof intrusion is a major cause of neck injury to belted occupants during rollover accidents. The correlation of reduced head room with increased injury risk has been demonstrated by the National Highway Traffic Safety Administration (NHTSA) and others such as the Insurance Institute of Highway Safety (IIHS). The current FMVSS 216 standard requires the vehicle roof, when loaded with a platen of prescribed geometry and application vector, to resist 1.5 times the vehicle empty weight before deforming 127mm. This standard was developed to ensure a modest level of safety of the vehicle in rollover. This paper demonstrates the relation between roof intrusions, available head room and belt pretension on occupant neck loads. A validated finite element model of a 2001 Ford Taurus is used to conduct an inverted drop simulation. The vehicle’s roof impacts an ideally rigid surface with 5 deg of roll and 10 deg of pitch. A 95th percentile Hybrid III ATD (Anthropomorphic Test Device) is used to simulate a large occupant. The simulations are conducted both for a production roof and a modified stiffer, stronger roof. The production roof is modified by addition of extra material in the B-pillars and A-pillars to enhance strength. A seatbelt pretensioner is also modeled to demonstrate the effectiveness of belt pretension in attenuating neck loads. This study demonstrates the inadequate performance of the subject production roof in preventing neck injury. The stronger roof in association with the belt pretensioner reduces the magnitude of the neck loads sufficiently to prevent injury. This study indicates that strong, non-deforming roofs along with belt pretension diminishes neck injury.

Rollovers continue to be a major source of heavy truck fatalities when compared to other accident modes. Real world rollover accidents are analyzed and two distinct damage patterns are identified. Damage to heavy truck roofs can occur from lateral loading that transitions to vertical roof loading as the vehicle rolls onto its side and then over onto its roof. A second load path can occur when the vehicle has rolled onto its side and furrows into the ground generating large longitudinal friction forces between the roof and ground. A review of the previous literature and various test methodologies are presented. A sled impact test methodology is presented which allows for structural assessment of a heavy truck cab’s crashworthiness in both of these loading environments. Two test series are presented using the sled impact test methodology in order to analyze real world truck rollovers using varying impact platen and contact angles. The structural deformation and failure patterns were found to be consistent with damage seen in real world accident vehicles. In each case, a second equivalent truck cab was then reinforced and tested under similar conditions to evaluate the energy management and crush resistance of a stronger cab structure. These structural reinforcements demonstrated a substantial reduction in roof crush and protected the survival space of the occupant compartment.