Vertical Panels Research Articles

Integrated approach for seismic vulnerability analysis of historic massive defensive structures

Abstract This paper illustrates a multidisciplinary integrated approach for analysing the seismic vulnerability of historical massive defensive structures. To this end, a fortress having massive walls, internal discontinuity surfaces, cavities and internal passages organized in a complex three-dimensional geometry, is used as testbed structure. The presented workflow should be considered as a contribution to define a general framework and foster the development of guidelines for seismic vulnerability analysis of historic massive structures. In fact, massive constructions cannot be modelled as an assembly of vertical panels, horizontal floors, towers and vaults, as is the case of other more common building typologies, such as churches and palaces, for which codified catalogues of collapse mechanisms are available.

Effects of environmental complexity on fearfulness and learning ability in fast growing broiler chickens

Increasing environmental complexity, i.e. by providing environmental enrichment, has been suggested as a way to improve broiler chicken welfare. One issue affecting broiler welfare is the level of fearfulness of the flock. Exaggerated fear responses may cause smothering and mortality. Environmental complexity has been found to reduce fearfulness in several species. It is known to promote the development of cognitive functions, including learning and memory. The aim of this study was to test the hypothesis that housing environments of different complexity, due to environmental enrichment or manipulation of standard resources, have an effect on learning ability and fearfulness in broilers. Fifty-eight pens with approximately 500 broilers in each (Ross 308), corresponding to a stocking density of 40 kg/m2, were used. Commercial feed and water were provided ad libitum, and wood shavings were used as litter material. Five environmental enrichment treatments (roughage, vertical panels, straw bales, elevated platforms at different heights), three treatments where the standard resources had been manipulated (increased distances between feed and water, lower stocking density) and one control group were randomly assigned to each pen. At 21 d, 10 broilers from each pen with treatments straw bales, elevated platforms, lower stocking density and control group were tested in a passive avoidance-learning task. At 31 d, 30 broilers from each pen from all treatment groups were subjected to a tonic immobility test. There was a tendency for broilers housed with access to straw bales to have better performance in a passive avoidance-learning task compared to broilers in the control group (F3,92 = 2.22; P = 0.091). In addition, chicks housed with access to 30 cm elevated platforms displayed shorter duration of tonic immobility compared to chicks housed with increased distance between feed and water (F8,49 = 2.22; P = 0.041; Tukey’s test P = 0.038), suggesting decreased fearfulness. The results show that increasing environmental complexity can have positive effects on decreasing fearfulness and promoting learning ability in broiler chickens, improving their welfare.

The Influence of Using Vertical Solar PV in Rationalization of Energy Consumption in Residential Buildings

AbstractAs a result of repetitive terroristic attacks in Rafah city, the Egyptian government had to evacuate Rafah to eradicate terrorism. It is planned to build New Rafah city at a distance from the borders.So if we are going to build a new settlement why not to build it right?The aim of this research is to build new Rafah city convenient to their occupants by fulfilling both psychological and physical comfort.This paper demonstrates a number of climatic and energy characteristics of building in the desert of the hot arid region. It presents proposed techniques for using vertical solar Photovoltaic Panels (PV) that installed on building facades. Designer can find out suitability for putting PVs installation in the facade surfaces of buildings using Google Earth imagery and ArcGIS software for spatial and attribute data of buildings in this defined urban study area. The approach entails modeling the solar irradiance characteristics of the site by fitting the probability distributions of the solar irradiance data measured during the day. Thereafter; it could be estimated the solar radiations factor according to analysis of different designs of PV modules. The module with the highest average factor is identified as the best suited module for the given site.

Effects of Geofoam Panels on Static Behavior of Cantilever Retaining Wall

Geofoam is one of the geosynthetic products that can be used in geotechnical applications. According to researches, expanded polystyrene (EPS) geofoam placed directly against a rigid retaining wall has been proposed as a strategy to reduce static loads on the wall. This study employed a finite difference analysis using a 2‐D FLAC computer program by considering yielding and nonyielding states for retaining walls to explore the effectiveness of geofoam panels in improving the static performance of cantilever retaining walls. Retaining walls at heights of 3, 6, and 9 meters and geofoam panels with densities of 15, 20, and 25 (kg/m3) at three relative thicknesses of t/H = 0.05, 0.2, and 0.4 were modelled in this numerical study. In addition, the performance of the double EPS buffer system, which involves two vertical geofoam panels, in retaining walls’ stability with four panel spacing (50, 100, 150, and 200 cm) was also evaluated in this research. The results showed that use of EPS15 with density equal to 15 (kg/m3) which has the lowest density among other geofoam panels has a significant role in reduction of lateral stresses, although the performance of geofoam in nonyielding retaining walls is better than yielding retaining walls.

Introduction of human physical measurements in the early design of a nuclear main control room

A nuclear main control room (MCR) is a crucial part of a nuclear power plant (NPP) where qualified staffs are monitoring and controlling the function and productivity of the whole plant. In a safely operated NPP, the performance of MCR personnel is critical. A properly designed MCR and human-system interface (HSI) is central to safe and efficient operations of the plant, since it reduces the occurrence of incidents, accidents and the risks of human related errors; thus, the physical characteristics of the users must be considered in the design of the MCR, taking into account the height and size of those users. The design of large display panels, control consoles, vertical control panels, and machinery rooms must be adequately designed, and the application of the anthropometric principles in all design stages of the MCR is crucial. When human anthropometry is taken into considerations in the design process, the MCR suits better the capabilities and limitations of the operators. During the design process, manufacturers and designers should consider the sizes, shapes, abilities, and constraints of the people for whom they are designing the MCR since anthropometric data varies significantly between different communities in various geographical territories.

The contribution of water surface Fresnel reflection to BIPV yield

Abstract Fresnel reflection on a water surface is highly variable throughout the year and can have a significant influence on building-integrated vertical PV panels, yet is generally disregarded in yield calculations. We analyze beam irradiances of two horizontal pyranometers situated next to a lake, one facing upwards and one facing downwards, to estimate the contribution of Fresnel reflection to the beam irradiance on a vertical surface. We show that in general the observed beam irradiance on the downward facing instrument matches the calculated Fresnel reflection. In contrast to other studies investigating water albedo, we also found that the reflection percentage decreases consistently with higher wind speeds and lower solar zenith angle. Fresnel reflection has the highest contribution for vertical surfaces in winter, with varying contributions between 30% of monthly global irradiance over the course of one year for different latitudes, and should thus be included in yield estimates for building integrated PV installations situated next to bodies of water.

Friction-based dissipative devices for precast concrete panels

Abstract The stability of precast concrete wall panels under seismic action can be ensured by means of dissipative systems of panel-to-panel connections that allow to control the level of forces and limit the displacements. This paper deals with a connection system consisting of friction-based devices inserted into appropriate recesses within the joints between vertical or horizontal panels. The results of experimental tests carried out on single connectors, as well as on structural sub-assemblies consisting of two full scale panels, are presented. The technological choices of materials and components that ensure a stable hysteretic behaviour of the devices are discussed. The effectiveness of the devices in improving the seismic performance of precast buildings under seismic action is also shown based on the results of cyclic and pseudo-dynamic tests on full-scale structural prototypes.

Pressure of Fiber Reinforced Concrete Mixtures on Vertical Formwork Panels

The article describes the developed methodology and installation for the experimental determination of concrete mixture pressure on the vertical formwork panels. This methodology is based on main positions of the strength of materials. The article presents the results of experiments on the pressure of deposited fiber reinforced concrete mixtures of different composition on the vertical formwork panels. The authors carry out the analysis of obtained results and draw generalized diagrams. The analytical formula for pressure of concrete mixtures is worked out and dimensionless factors in this formula are determined mathematically. The dimensionless factors are approximated by power functions with good convergence with actual values. The obtained results enable the reduction of the design values compared with those in the regulatory documentation.

Seismic response of precast structures with vertical cladding panels: The SAFECLADDING experimental campaign

The SAFECLADDING Project was aimed at improving the connection systems between cladding panels and precast RC buildings in seismic-prone areas. Three design criteria have been assessed: isostatic, dissipative and integrated. They can be realised using different strategies, which are represented by several test setups within the experimental campaign.The paper describes the results obtained with vertical panels arrangement and the comparison with the bare frame, which is the reference for the current design practice that considers panels like non-structural elements. The mock-up and the test sequence were designed to assess all setups with a single frame structure. The mock-up was a one-storey building, made by two parallel frames with two bays and square columns, inserted into pocket plinths. The building was designed for earthquake actions according to the Eurocode 8. Each setup was assessed using increasing levels of action, either with cyclic or pseudo-dynamic tests. The latter were performed both for serviceability and ultimate limit states. The experimental programme for vertical-panels and the bare-frame arrangement involved ten different setups, resulting in a total of twenty-eight tests.As for the isostatic criterion, the results confirm that considering panels as simple masses without stiffness is far from the real system behaviour, even using apposite devices to uncouple panels and frame displacements. In fact, despite a previous and positive experimental qualification, several devices failed in operative conditions tests.Conversely, the integrated criterion requires to bear high loads, transferred by the frame through connections, which becomes the weak point for this configuration, as demonstrated by different failures of bolts and connections.The reliability of the dissipative criterion has been confirmed by twelve tests completed without any damage. This solution in fact combines lower relative displacements with limited loads within connections, avoiding both the compatibility problems and excessive forces.

DEVICE FOR VERTICAL PANELS MOUNTING

The article analyzes operations ways and mounting device of long sandwich panels as enclosing structures. It is evaluated that at the moment there are no reliable auxiliary mounting devices for vertical panels at high altitude. Proposed device improves the quality of operations and increases performance. Device is protected by license. For the first time construction features are described in details. Device gives to mounters an opportunity to work staying on the construction’s surface that is already attached on the building frame.

Fluid flow and heat transfer in PCM panels arranged vertically and horizontally for application in heating systems

The rectangular panel is within the most common geometries in phase change materials (PCM). Nevertheless, there is a lack of knowledge regarding how the arrangement (vertical or horizontal) and thickness affect heat flux and phase change duration. Such knowledge would be very helpful both in the design of PCM heat exchangers. This paper studies the behavior of the RT60 paraffin, Pr ≈ 330, phase change temperature between 53 and 61 °C; and the fatty acid Palmitic Acid, Pr ≈ 110, phase change temperature of 65 °C. Parametric studies analyzing the influence of: temperature of the walls (5 × 105 < Ra ≤ 2 × 106), phase change processes (melting and solidification), panel position and PCM thickness (aspect ratio1/20 and 3/20) are performed. The flow behavior is analyzed over time using velocity plots and volumetric liquid fraction contours. The formation of Bénard cells and their evolution is described. Free convection dependence of dimensionless string function and Rayleigh number is discussed. Free convection during melting for horizontal panels becomes very important and the mean heat fluxes increase up to twofold compared to vertical panels. For solidification, however, conduction becomes more relevant. The importance of both mechanisms is highlighted by calculating heat transfer rates.

Cyclic response of hammer-head strap cladding-to-structure connections used in RC precast building

During the recent earthquakes in the Emilia-Romagna region of Italy, the cladding-to-structure connections which were installed in industrial precast buildings did not perform as had been expected in their design. According to the findings of some field reconnaissance reports, in several precast buildings collapse of cladding panels occurred. This indicated the need for new research and improvements in the design and execution of such connections. In this study the cyclic response of a cladding-to-structure connections which is most commonly used in the current European design practice of precast buildings was experimentally and analytically investigated. Such connections consist of cold-formed or hot-rolled channels and hammer-head straps. They provide the out-of-plane restraint at the top corners of vertical or horizontal panels. Up until now no information has been available, in the existing literature, about the cyclic response of such connections in the plane of the cladding panels. The results of the performed experimental studies were used to develop reliable numerical models of typical connections, and to define appropriate procedures for the safe design of in-use connections.

Seismic fragility functions of industrial precast building classes

The seismic vulnerability of twelve industrial precast building classes has been investigated by conducting nonlinear dynamic analyses on sample buildings from these building classes and taking into account selected seismic events. The results of the study can be used for seismic risk and loss estimation of precast building stock by considering the collapse of buildings and several other damage states, which were defined on the basis of the physical damage occurring to the vertical panels, horizontal panels, or masonry infills. The use of fragility functions derived on the basis of spectral acceleration corresponding to the so-called optimal period of the building class is suggested. Fragility functions are also presented for the peak ground acceleration, which is an intensity measure, independent of the building class. This means that all these fragility functions can be used to discuss how the variation of structural configurations, code levels, and the type of non-structural components and their fastenings affect the overall seismic response of industrial precast building classes, at a given level of the seismic intensity measure. It can be concluded that the vulnerability of non-structural elements is the largest in the case of precast buildings with horizontal panels, followed by those with masonry infills and vertical panels. It was also observed that non-structural components have an impact on the structural collapse, both in terms of reducing the median and increasing the dispersion of the collapse fragility functions. It was also observed that a higher seismic design force may worsen the seismic performance of a precast building if the connections are not adequately designed.

Experimental characterisation of cork agglomerate core sandwich panels for wall assemblies in buildings

In recent times, the construction market has seen a very significant increase in the demand of prefabricated solutions of nonstructural elements, such as sandwich panels for buildings walls. Due to the inherent low weight, good mechanical behaviour, ease of assembly and cost-effectiveness, these types of wall assemblies are especially competitive in construction of single-family houses or one unit dwelling structures.However, the low fire resistance of many of these solutions, such as sandwich panels with expanded polystyrene core or polyethylene terephthalate foam core, precludes their use in buildings with more than one floor. The substandard fire resistance is generally due to the fact that the constituent materials are combustible or, at least, their properties are extremely sensible when subjected to high temperatures or flame.Given the isolation properties, good mechanical damping and fire resistance, cork agglomerate can be used as the core material for sandwich panels. However, this material is heavier than the other materials commonly used as core for sandwich panels. In order to deal with this drawback, it is necessary to choose a material for the panel facings that could fulfil the mechanical requirements and the condition not excessively increase the panel weight. The use of a glass fibre reinforced polymer seemed a suitable solution for the facing component. Therefore, the proposed wall assembly solution consists in a sandwich panel with cork agglomerate core and glass fibre reinforced polymer facings.The scope of this work was the assessment of the feasibility of a new configuration of vertical (wall) sandwich panels that could, not only be a cost effective solution for prefabricated construction, but also provide good mechanical performance and fire resistance. This sandwich wall panel configuration was tested for characterisation of its mechanical behaviour, resistance to impact and to fire. The results of the experimental campaign carried out are presented in this manuscript along with some conclusions about the suitability of this solution as sandwich wall panel for buildings façades.

Bifacial photovoltaic panels field

Bifacial solar cells may produce more output energy than mono-facial solar cells because both sides of the cell, front and rear, can absorb solar radiation. This occurs when the nearby ground or other artificial surfaces are highly reflective. A gain in output power of 5–20% has been reported in the literature for special applications. The present article deals with the calculation of the annual incident irradiation on a solar field comprising of bifacial photovoltaic panels deployed in multiple rows and separated by a distance between the rows. These types of fields are designed for large scale solar electricity production. The calculation of the annual incident irradiation is compared between two types of deployments: (a) bifacial photovoltaic panels installed with an optimal tilt angle facing south, (b) bifacial photovoltaic panels installed vertically and facing the east-west direction. The study shows that bifacial photovoltaic panels installed with an optimal tilt angle may produce 32% more energy than vertical bifacial photovoltaic panels, for the same environmental conditions. On the other hand, more vertical collectors can be installed in fields with the same field dimensions.

Experimental analysis and modeling of two-way reinforced concrete slabs over different kinds of yielding supports under short-term dynamic loading

This paper presents the experimental and theoretical results of an investigation carried on reinforced concrete plates placed on yielding supports along their perimeter under short-term dynamic loading. The yielding supports are made of elements with annular cross-section. Their functionality allows operations in elastic and elasto-plastic stages with a further turning to hardening stage. This particular support scheme has been adopted in order to simulate the different boundary conditions that r.c. slabs subjected to impacts may encounter in practical applications of civil engineering (e.g. roofs, vertical panels, retaining walls, guardrails, etc.). The experimental results showed that influence of support deformability on the structural response under impact depends on their rigidity and on the deformation stage. The results of numerical simulations based on a simple mechanical model qualitatively agree with the experimental results. Therefore the model can be adopted for simulation and design of reinforced concrete panels under impact or high-strain loading situations.

The Effectiveness of Horizontal Barriers in Preventing Fire Spread on Vertical Insulation Panels Made of Polystyrene Foams

Expanded polystyrene (EPS) and extruded polystyrene (XPS) foams are both excellent exterior thermal insulation materials for buildings. However, their flammability also induces high fire hazard. Current regulation in China requires horizontal fire barriers with a minimum height of 30 cm when polystyrene foams are used as the external insulation. The present work evaluates the effectiveness of such barriers in inhibiting fire growth in insulation walls. The walls were made of B2 grade EPS and XPS foams without protective coatings but with mineral wool as horizontal barriers. Altogether six combinations of fire positions and barrier positions were tested for both EPS and XPS. The heat release rate (HRR) of the fire and the temperature distribution on the wall were recorded and analyzed. The results indicate that, without a barrier, fire starting at the middle of the wall generated higher peak HRR than that starting at the bottom, which was in turn higher than that starting at the top. When the insulation panel below the barrier was 1 m high, the upward fire spread from the bottom could be stopped by 40-cm, but not 30-cm, barriers. However, when the insulation panel below the barrier was 2 m high, even the 40-cm barriers failed. Lastly, the downward fire spread from above could not be stopped by 40-cm barrier due to dripping of burning plastics. The study highlights the limitations of horizontal fire barriers in preventing the vertical fire spread over exposed B2 grade polystyrene insulation and establishes protocols for further investigations.

Antireflection coatings for solar panel power output enhancement

ABSTRACTThe impact of nanostructured broadband antireflection (AR) coatings on solar panel performance has been projected for a broad range of panel tilt angles at various locations. AR coated films have been integrated on test panels and the short-circuit current has been measured for the entire range of panel tilts. The integration of the AR coatings resulted in an increase in short-circuit current of the panels by eliminating front sheet reflection loss for a broad spectrum of light and wide angle of light incidence. The short-circuit current enhancement is 5% for normal light incidence and approximately 20% for off-angle light incidence. The National Renewable Energy Laboratory (NREL) System Advisor Model (SAM) predicts that this AR coating can yield at least 6.5% improvement in solar panel annual power output. The greatest enhancement, approximately 14%, is predicted for vertical panels. The AR coating’s contributions to vertical mount panels and building-integrated solar panels are significant. This nanostructured broadband AR coating thus has the potential to lower the cost per watt of photovoltaic solar energy.

Kilka uwag na temat antycznej metrologii oraz ceramiki attyckiej okresu geometrycznego i zasad jej dekoracji

The article deals with the ancient metrology and a possible recognition of the rules determining ornamentation observed on Attic geometric pottery. While referring to former studies, the author presents ornamentation of Attic geometric pottery, revealing an exceptional standardisation and repetitiveness of elements, as having two developmental tendencies. One concerns horizontal arrangement of decorative motifs, placed in surrounding belts, while the other decoration is put in vertical panels, focusing. These both tendencies in the course of development of Attic geometric period become one harmonized whole. It is also possible to demonstrate on an example of monumental became from Athens (inv. NM 804), that the vessel was exactly twice as tall as the biggest width of its body, as well as that ornaments covering its whole surface have been made according to an accepted module. The author suggests that such a way of thinking and ordering activities should not be interpreted as proving the beginnings of classical mathematical thinking, which is to develop later. However, metrological analyses of ancient artefacts suggests that such objects as Attic geometric pottery may permit recognition of already existing disposition of its creators for visual representations of experienced reality and for attempts made to generalize these experiences.

Advanced Flexible CIGS Solar Cells Enhanced by Broadband Nanostructured Antireflection Coatings

ABSTRACTFlexible copper indium gallium diselenide (CIGS) solar cells on lightweight substrates can deliver high specific powers. Flexible lightweight CIGS solar cells are also primary candidates for building-integrated panels. In all applications, CIGS cells can greatly benefit from the application of broadband and wide-angle AR coating technology. The AR coatings can significantly improve the transmittance of light over the entire CIGS absorption band spectrum. Increased short-circuit current has been observed after integrating AR coated films onto baseline solar panels. NREL’s System Advisor Model (SAM) has predicted up to 14% higher annual power output on AR integrated vertical or building-integrated panels. The combination of lightweight flexible substrates and advanced device designs employing nanostructured optical coatings together have the potential to achieve flexible CIGS modules with enhanced efficiencies and specific power.