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Copyright of VLC Arquitectura is the property of VLC Arquitectura and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Purpose: To be able to walk safely up or down a staircase, we must be able to judge the configuration and slope of the staircase and our viewing position. Adding markings to the stairs might help form correct perceptions of the staircase geometry. In this study, we examined how visual judgements about staircase configuration are affected by different marking patterns. Methods: Fifteen normally sighted young participants viewed computer‐generated images of staircases as seen from the top landing of the stairs. Marking patterns included contrasting baseboard, transverse edge‐stripes, longitudinal side‐stripes, longitudinal stripes, diamond patterns, longitudinal stripes extended to landing and diamond patterns extended to landing. For comparison, we included the no‐marking condition as a control. We tested several contrast levels of marking patterns (3.2%–50%), pitch lines of the staircases (shallow/medium/steep) and viewing positions (left/centre/right). The effect of the overall shape cue of the staircase on participants' performance was also evaluated. We measured participants' accuracies in judging whether the staircase was shallow, medium or steep, and whether the viewing position was located to the left, centre or right. Results: Transverse edge‐stripes markings yielded fewer underestimations of slope (9% [transverse] vs. 18% [others]) when compared with other markers. The presence of an overall shape cue helped both slope (67% [presence] vs. 51% [absence]) and viewing position judgements (79% [presence] vs. 62% [absence]). When the overall shape cue was present, only the transverse edge‐stripes markings yielded a significant improvement in performance (compared with no‐marking condition). When the cue was absent, performance was significantly better with markings with high and moderate contrasts. Conclusions: Adding marking patterns such as high‐contrast transverse stripes to stairs may help enhance the visibility of the stairs and judgements of staircase geometry. This might be particularly useful for people with visual impairment or normally sighted individuals under compromised environmental conditions. [ABSTRACT FROM AUTHOR]

Modern gas turbines have evolved by increasing the turbine inlet temperature (TIT) to improve performance. This development has led to a demand for cooling techniques. Among these, the film cooling, which involves injecting compressed air through holes on the turbine surface, is a prominent cooling technique used to protect the turbine surface. In this study, a comparative analysis is conducted between the conventional fan-shaped film cooling hole, primarily used in film cooling techniques, and modified shapes achieved by altering the geometry of the film cooling hole based on a fan-shaped hole to assess and compare the cooling performance on a flat plate surface. The adiabatic film cooling effectiveness was measured for three film cooling holes, the Baseline of a 7-7-7 fan-shaped film cooling hole, namely, Staircase, which had a double-step at the hole exit, and Compound Expansion, which had an additional expanded flow path at the hole leading edge. The used measurement technique was the pressure-sensitive paint (PSP) technique, using nitrogen gas as the foreign gas, and experiments were conducted at a density ratio of 1.0 and blowing ratios ranging from 0.5 to 2.0. The results reveal that the modified holes featured wider lateral expansion at the hole exits, resulting in a broader distribution of the cooling effectiveness in the lateral direction compared to the Baseline. The Staircase shows a better performance, although an overall cooling effectiveness trend similar to that of the Baseline. Furthermore, the Compound Expansion demonstrates an enhancement in the cooling performance with an increased blowing ratio, notably achieving nearly double the cooling effectiveness compared to that of the Baseline at a blowing ratio of 2.0. [ABSTRACT FROM AUTHOR]

Several studies have previously been conducted to improve the cooling performance of film cooling. However, most of the research has conducted experiments with film cooling holes on flat plates, and thus, the results of these studies do not encompass the influence of the complex mainstream behavior within the turbine passage on film cooling. In this study, three different film cooling hole configurations were installed on the endwall of a turbine linear cascade to measure adiabatic film cooling effectiveness and evaluate cooling performance. The film cooling holes compared in the experiment for film cooling effectiveness were a 7-7-7 fan-shaped hole (Baseline), a Baseline with a double-step structure at the hole exit (Staircase), and a Baseline with an additional expanded passage at the hole leading edge (Compound Expansion). A total of nine holes were manufactured on the turbine endwall to assess film cooling performance, as various factors, such as mainstream acceleration, secondary flow within the turbine passage, and so on, can influence film cooling. Adiabatic film cooling effectiveness was measured using the pressure-sensitive paint (PSP) technique. Mass flow ratios ranging from 0.25% to 1.25% of the mass flow rate of a single turbine passage were supplied to the plenum chamber within the test rig. As a result, all experimental results confirmed the impact of secondary flow within the turbine passage on film cooling. In the case of the Staircase, it exhibits an overall cooling trend similar to the Baseline. It shows small cooling performance degradation compared with Baseline due to lift-off, and its double-step structure laterally expanding results in better cooling performance at high mass flow ratio (MFR) conditions. For the Compound Expansion, at low MFR, the momentum of the coolant is lower compared with other configurations, leading to lower cooling performance due to the influence of secondary flow. However, at high MFR, the Compound Expansion provides wider protection compared with other hole geometries and shows high cooling performance. [ABSTRACT FROM AUTHOR]

One of the most precise methods to establish psychometric functions and estimate threshold and slope parameters is the constant stimuli procedure. The large distribution of predetermined stimulus values presented to observers enables the psychometric functions to be fully developed, but makes this procedure time-consuming. Adaptive procedures enable reliable threshold estimation while reducing the number of trials by concentrating stimulus presentations around observers' supposed threshold. Here, the stimulus value for the next trial depends on observer's responses to the previous trials. One recent improvement of these procedures is to also estimate the slope (related to discrimination sensitivity). The Bayesian QUEST+ procedure (Watson Journal of Vision, 17(3), 10, 2017), a generalization and extension of the QUEST procedure, includes this refinement. Surprisingly, this procedure is barely used. Our goal was to empirically assess its precision to evaluate size, orientation, or temporal perception, in three yes/no discrimination tasks that increase in demands. In 72 adult participants in total, we compared points of subjective equivalence (PSEs) or simultaneity (PSSs) as well as discrimination sensitivity obtained with the QUEST+, constant stimuli, and simple up-down staircase procedures. While PSEs did not differ between procedures, sensitivity estimates obtained with the 64-trials QUEST+ procedure were overestimated (i.e., just-noticeable differences, or JNDs, were underestimated). Overall, agreement between procedures was good, and was at its best for the easiest tasks. This study empirically confirmed that the QUEST+ procedure can be considered as a method of choice to accelerate PSE estimation, while keeping in mind that sensitivity estimation should be handled with caution. [ABSTRACT FROM AUTHOR]

The study presents a possible innovative use of cement fiber boards (CFBs) reinforced with cellulose fibers for construction of an interior prefabricated staircase. Regarding the unusual use of traditional material that was used in all bearing elements of the staircase, a numerical simulation with the use of a material model SBETA was carried out and, subsequently, multiple experimental static loading was applied. In order to carry out experimental testing of static load capacity, a full-scale experiment method was chosen and performed on a real staircase structure for family houses. The full-scale experiment is considered the most precise method to test structures or material behavior. The obtained results show that the designed and tested staircase structure of CFBs is able to meet the requirements of technical standards related to static loading of staircases. The load test confirmed the potential use of cement fiber boards produced by the Hatschek process for real bearing structures under static loading. [ABSTRACT FROM AUTHOR]

A rubber isolation bearing installed in a staircase (RBS) was proposed to mitigate seismic damages to the component of staircases and improve their seismic performance. A series of quasi-static tests performed with respect to the horizontal and vertical mechanical properties of RBS as well as the numerical modelling were verified with experimental results. Next, the finite element models of typical types of reinforced concrete frames (without stairs, with cast-in-place reinforced concrete stairs, and with RBS stairs) were established. The modal dynamic and non-linear elasto-plastic analyses of system-level building models were herein conducted, respectively. The effect of the RBS on the dynamic response of the whole structure and the mechanical performance of stair components was revealed. The analysis results indicated that the RBS provided the desired floor-to-floor relative drift and effectively isolate the seismic action from the stair flight. Therefore, the presence of RBS can effectively mitigate the influence of a staircase on the entire building's structure, weaken the diagonal strut effect of flights, and reduce the inner forces of staircase components. [ABSTRACT FROM AUTHOR]

Staircase testing is a standard method for evaluating the fatigue strength of components. However, staircase testing assumes a normal distribution, while components can display bimodal behavior due to flaws in material, or issues during the manufacturing process. Three unique step loading data sets on different production crankshafts provide evidence that step loading reliably identifies material or manufacturing issues, which lower a component's fatigue strength. Staircase testing has an 87% or greater chance of overestimating the component's fatigue strength, which in turn overestimates the component's expected reliability. For example, a component with a 99.9% reliability based on staircase testing would only have a 74% reliability based on step loading. If a component contains an undetectable manufacturing defect, staircase testing has a 99% chance of overestimating the component's fatigue strength. Step loading reliably improves the estimation of a component's fatigue strength distribution while providing insights into a component's defect tolerance. Highlights: Staircase testing overestimates a component's fatigue strength.Step loading reliably identifies issues that lower a component's fatigue strength.Step loading improves estimation of a component's fatigue strength distribution. [ABSTRACT FROM AUTHOR]

In this work, we conducted downward evacuation experiments in four types of staircases under various smoke visibility conditions of the naked eye, wearing sunglass and wearing eyeshades. Ten male and ten female college students were recruited to conduct the evacuation as a single male, single female, two males supporting one another, two females supporting one another and one male carrying another on his back. The evacuation time on each floor was recorded. The corresponding evacuation models were established by Pathfinder and verified against the test data. The effects of evacuation crowd density and response time considering gender factors on the evacuation time were simulated using the models. The results show that under the experimental condition of low visibility, the curve of evacuation time presents a stable state, whose change with the increase in the floors is not obvious. The increase in the evacuation time under different visibility indicates that males have better adaptability to the environment than females. The curves of SSP (straight running stairs with platform) and DSS (double split parallel stairs) are smoother than those of DPS (double running parallel stairs) and CS (corner stairs), indicating less pressure and less congestion during evacuation. During the emergency evacuation, the crowd pressure on the platform of the staircases is small. The front section of the flight and the corner part of the staircases are prone to congestion during evacuation. Under the influence of gender factors, since the response time of males is longer than that of females, the smaller the proportion of males, the smaller the time growth rate considering the reaction time. With the increase in crowd density, the effect of response time on total evacuation time becomes smaller. [ABSTRACT FROM AUTHOR]

In this communication, a low-profile circularly polarized (CP) staircase curl antenna array with 2:1 impedance bandwidth and 50% axial ratio (AR) bandwidth is proposed for fifth-generation (5G) millimeter-wave (mmW) communications. It overcomes a vital drawback of complex multilayer structure of the wideband CP antenna array. By fully taking advantage of 3-D staircase layout, the curl element achieves 2:1 impedance bandwidth, 57.9% AR bandwidth, and a maximum gain of 7.4 dBic. Accordingly, benefiting from the tapered matching transformer, a single-layer full-corporate microstrip feeding network with 111.4% impedance bandwidth is constructed. For demonstration, an $8\times8$ staircase curl antenna array is designed on three-layer PCB laminates. The proposed antenna array is measured with an impedance bandwidth of 76.9% (20.0–45.0 GHz) and an AR bandwidth of 53.6% (23.1–40.0 GHz), demonstrating a promising candidate to be used in 5G mmW communications. [ABSTRACT FROM AUTHOR]

The external wind can change smoke movement patterns inside the staircase and affect smoke exhaust efficiency. This paper analyzes the smoke back-layering phenomenon in the staircase with open stair doors below the fire floor. The effect of the open stair door location and the heat release rate of fires and external wind velocities on smoke movement patterns are investigated numerically. The external wind ranges from 0–5.5 m/s. At 0 m/s, the smoke back-layering phenomenon driven by pressure difference can be found in the staircase with all stair doors closed. With the increasing wind velocity, four smoke behaviors are identified: upward moving smoke, first downward then upward moving smoke, downward moving smoke, and no smoke. Results show that the back-layering distance is mainly influenced by the external wind and heat release rate of fires. Correlations are modified and used to predict the longest back-layering distance with the first downward then upward moving smoke. This helps with arranging the smoke detectors inside a staircase and the fire safety design of high-rise buildings. [ABSTRACT FROM AUTHOR]

Laboratory-based fatigue test methods are often used to estimate the life of components in service conditions. Two common laboratory-based methods used for fatigue durability are the Staircase and the Over-Stress Probe (OSP) methods. Both methods are widely used in academia and industry; both have benefits and limitations in adequately providing for a lifespan estimation. A study was conducted to examine the results from staircase and OSP fatigue tests on 176 specimens taken from AlSiCuMg engine block castings. The OSP method was found to allow a more complete fractographic assessment of porosity compared to the staircase method. It is concluded that the OSP method yields information to better drive decisions regarding process changes that influence desired specific outcomes in terms of product performance and durability. [ABSTRACT FROM AUTHOR]

This article analyses the 'stair culture' of Hong Kong Island, a place that is constrained by its topography, economic, and social-historical conditions. Staircases are interwoven into an infrastructure of vertical and horizontal pathways. Instead of just being a means of access, staircases play a key role in shaping the urban island. Through a critical examination of these structures and relevant literary and filmic texts (Leung Ping-Kwan's poems, Wong Kar-wai's films, and Tsai Ming-liang's Walker series [2012]), the article provides a way of understanding the extent to which the perception of Hong Kong Island is re-imagined by way of an urbanscape punctuated by staircases. Staircases have the ability to mix up people in different classes in such places as the Central to Mid-Levels area and Sai Ying Pun Centre Street. Both districts are initially connected by staircases and later escalators. By examining the impact of escalators (such as high-speed gentrification, closing down of local stores, and the loss of real public spaces) and the effects of staircases on cultural activities in different areas, this article argues that staircases expose the nature of a classed society in Hong Kong Island - and, by extension, Hong Kong as a whole - and represent a nostalgia that is potentially productive. [ABSTRACT FROM AUTHOR]

Fire is one of the most common risks to the environment and human health. Fire, depending on the conditions of combustion and the type of fuel, can emit many toxic products. The paper presents numerical analyzes of the conditions that can occur in a building during a fire. The conditions were analyzed in terms of the safety of the occupants and possible emissions of pollutants into the atmosphere. The temperature, propagation of smoke, and emission of pollutants were analyzed. A numerical model was created using Fire Dynamics Simulator (FDS) software. The model represents a staircase and a corridor in a real building located at the Silesian University of Technology in Poland. The results show that safe conditions are only ensured for a limited time, and emissions can also be harmful to occupants and the environment. [ABSTRACT FROM AUTHOR]

To quantitatively assess the risks of pedestrian evacuation through staircases with different slopes when a flood intrudes into the underground space, a numerical model was designed to simulate flood flow patterns on staircase and escalator under different slope conditions (26.6°, 28.2°, 29.1°, 30°, and 35°). A safety index (F (v2, y)) was employed to assess the risks of pedestrian evacuation through the staircase under different slopes. When the water depth at the staircase entrance (under slopes ranging from 26.6° to 28.2°) was 0.3 m and the unit width discharge was 0.28 m2/s, pedestrians safely evacuated the underground space. However, when the staircase slope was beyond 28.2°, the safety index value was higher than the critical value and the flood caused serious threats to them. Therefore, it is suggested that when the underground space becomes flooded, pedestrians should avoid steep slopes and choose a gentle staircase as a safer escape route. The obtained results provide a theoretical guideline for pedestrian evacuation from a flooded staircase. [ABSTRACT FROM AUTHOR]

Slabless reinforced concrete (RC) staircases attract architects with their aesthetically pleasing appearance and are therefore especially preferred for the interior design of prestigious buildings. The design and detailing of such staircases are based on analytical approaches and engineering judgment. However, these analytical methods are not supported by extensive experimental research. Besides, engineers have to deal with lots of uncertainties due to a lack of experimental data. Therefore, experimental research was conducted to investigate the flexural behavior of slabless staircases. A total of 12 two-thirds-scaled specimens with four different reinforcement arrangements and three different tread/riser thicknesses were prepared for testing under six-point monotonic loading. The results show that tread thickness, rather than riser thickness, significantly affects the behavior of slabless staircases. In addition, it has been found that the planar reinforcement can greatly improve the behavior and prevent possible bonding problems. The results are also consistent with the adopted analytical approaches. [ABSTRACT FROM AUTHOR]

In engineering applications, fatigue phenomenon is a key issue and needs to be analyzed in the beginning of design phase in case of any component exposed to alternating loading on operation otherwise catastrophic fatigue failure may cause. Component can be designed with safelife, fail-safe, and damage tolerant approach based on whether redundant load path and damage sensitive. Before starting analyzing the structure, material allowable data needs to be presented in a reliable way to predict fatigue life of components. SN curves with presented confidence levels are the robust approach to make a prediction on safe life of a structure in terms of fatigue. In this point, there are so many approaches to determine fatigue limit of materials and issue shall be handled by statistical manner. In literature, different staircase and curve fitting methods were presented to estimate endurance limit of materials and some reliability manuscript published. In this paper, fatigue limit of AISI 4340 steel will be investigated through most convinced staircase and curve fitting approaches and their reliability will be queried. [ABSTRACT FROM AUTHOR]

Introduction: Staircase is facilities functioned to connect floors. Stairs which are not ergonomic may cause fatigue and accident for the users. Universitas Airlangga Public Health Faculty Building is a three-story building. Each floor has 5 staircases on different sides. The aim of this study was to analyze the ergonomics aspects of the architectural design of the staircase. Method: This study used cross-sectional design with descriptive analysis. The measured dimensions of the staircase were riser's height, tread's depth, stairs width, stairs slope, landing, lighting level, handrail's height and diameter, and the presence of non-skid surface. The measurement tools were measuring tape, lux meter and cylinder bore gauge. Results: Measurement showed that all riser's height met the recommendation. Most tread's depth was below 30 cm. The width of Northwestern and Southwestern staircase was below the recommendation width, which was <125 cm. All slope of stairs was within the recommendation slope. The height and diameter of all handrails was 96 cm and 5.5 cm respectively and was above the recommendation. The lighting level during daytime on most staircase was above 100 lux but during nighttime was below 100 lux. There were landings that were wider than the stairs and non-skid surface at the edge of each tread. Conclusion: Most dimension of staircase (67.5%) in Universitas Airlangga Public Health Faculty Building met the design recommendation but the tread's depth, width of stairs, handrail's diameter and height, as well as the lighting on stairs need to be improved to make the stairs safer. [ABSTRACT FROM AUTHOR]

Copyright of Imagofagia is the property of Imagofagia - AsAECA and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper presents a general approach for modelling human–structure interaction in the case of vertical vibrations that is based on a model of the system and on a solution procedure that is able to account for the most complex dynamic conditions, such as people ascending/descending light staircases. The approach combines the effects of changes in pedestrians' positions along the structure and changes in pedestrians' postures during movement. Furthermore, the model used describes the coupled system composed by the structure and the people on the structure, splitting the actions of pedestrians into two components: passive and active forces. This approach and two further enhancements of the model were used to evaluate the dynamic interactions between pedestrians and a staircase, and the results were validated via an extensive experimental campaign carried out using a staircase in the Bovisa Campus of Politecnico di Milano as a test case structure. [ABSTRACT FROM AUTHOR]

During the seismic performance assessment of existing buildings, staircases are generally not taken into account as structural members but as dead load. Staircases, as secondary structural members, not only serve for connecting successive floors but also provide considerable amount of strength and stiffness to the building which can modify its seismic behaviour considerably. In this parametric study, the influence of staircases on the seismic response of substandard RC frame buildings which differ in number of storey and span, presence of staircase and its position has been examined. Modal Analyses and bi-directional Non-Linear Time History Analyses (NLTHA) were conducted to compare several engineering demand parameters (EDPs) such as inter-storey drift ratio (ISDR), floor accelerations, modal properties, member shear forces and plastic hinge distribution. Additionally, short column effect, variation in shear forces of columns that are attached to the staircase slab, failure and deformation in staircase models have also been investigated. As the staircase was considered in the analytical model, a different damage pattern can be developed especially in the structural components close to staircase. [ABSTRACT FROM AUTHOR]

This paper presents the results of the graphic analysis carried out on its most representative example to determine its possible tracing strategy, the imperial staircase of the Royal Monastery of San Miguel de los Reyes (Valencia). With the support of a telemetric survey using a 3D laser scanner, it has been verified the existence of an accomplished graphical method of design. The research has considered the operations recommended by stonecutting manuscripts and the constructive tradition of its predecessors, the «honour» staircases of the Mediterranean noble houses. This has allowed to consolidate a useful strategy for the study of this constructive variant; validate the proposals of the treatise writers and confirm the validity of the Late- Medieval methods of shape control using directional curves. [ABSTRACT FROM AUTHOR]

• Shorter or higher steps lead to shallower water depths but higher flow velocities. • A branch staircase has lower water depths and flow velocities than the main one. • Underground staircase transforms a subcritical flow into a supercritical flow. • Longer or lower steps, as well as branch lines, provide greater stability to the pedestrian. Underground flooding is intensifying due to urban expansion and more frequent extreme precipitation. Staircases are crucial for accessing underground spaces and evacuation during floods and it is of both academic and practical value to investigate how floodwater and the induced hazard evolve over underground staircases. This study examines flood dynamics on underground staircases and its relationship with staircase characteristics through a series of numerical experiments using a two-dimensional (2D) hydrodynamic model. The study also uncovers how staircase design influences flood hazard levels. Results indicate that shorter or higher steps lead to shallower water depths but higher flow velocities. The branch staircase experiences smaller water depths and flow velocities than the main one. The presence of staircase transforms a subcritical flow into a supercritical flow. Except in extremely deep floodwaters, pedestrians are more vulnerable to sliding than toppling on staircases. The stability of the human body is greater on steps with longer length and lower height (26.56°) or the branch line of the junction type. The relative stability of the human body is not necessarily a guarantee of complete safety and must be analyzed in conjunction with the comprehensive safety factor. [ABSTRACT FROM AUTHOR]

Finite difference is the most widely used method for seismic wavefield modeling. However, most finitedifference implementations discretize the Earth model over a fixed grid interval. This can lead to irregular model geometries being represented by 'staircase' discretization, and potentially causes mispositioning of interfaces within the media. This misrepresentation is a major disadvantage to finite difference methods, especially if there exist strong and sharp contrasts in the physical properties along an interface. The discretization of undulated seabed bathymetry is a common example of such misrepresentation of the physical properties in finite-difference grids, as the seabed is often a particularly sharp interface owing to the rapid and considerable change in material properties between fluid seawater and solid rock. There are two issues typically involved with seabed modeling using finite difference methods: firstly, the travel times of reflections from the seabed are inaccurate as a consequence of its spatial mispositioning; secondly, artificial diffractions are generated by the staircase representation of dipping seabed bathymetry. In this paper, we propose a new method that provides a solution to these two issues by positioning sharp interfaces at fractional grid locations. To achieve this, the velocity model is first sampled in a model grid that allows the center of the seabed to be positioned at grid points, before being interpolated vertically onto a regular modeling grid using the windowed sinc function. This procedure allows undulated seabed bathymetry to be represented with improved accuracy during modeling. Numerical tests demonstrate that this method generates reflections with accurate travel times and effectively suppresses artificial diffractions. [ABSTRACT FROM AUTHOR]

This paper presents a novel interactive system that provides users with virtual reality (VR) experiences, wherein users feel as if they are ascending/descending stairs through passive haptic feedback. The passive haptic stimuli are provided by small bumps under the feet of users; these stimuli are provided to represent the edges of the stairs in the virtual environment. The visual stimuli of the stairs and shoes, provided by head-mounted displays, evoke a visuo-haptic interaction that modifies a user's perception of the floor shape. Our system enables users to experience all types of stairs, such as half-turn and spiral stairs, in a VR setting. We conducted a preliminary user study and two experiments to evaluate the proposed technique. The preliminary user study investigated the effectiveness of the basic idea associated with the proposed technique for the case of a user ascending stairs. The results demonstrated that the passive haptic feedback produced by the small bumps enhanced the user's feeling of presence and sense of ascending. We subsequently performed an experiment to investigate an improved viewpoint manipulation method and the interaction of the manipulation and haptics for both the ascending and descending cases. The experimental results demonstrated that the participants had a feeling of presence and felt a steep stair gradient under the condition of haptic feedback and viewpoint manipulation based on the characteristics of actual stair walking data. However, these results also indicated that the proposed system may not be as effective in providing a sense of descending stairs without an optimization of the haptic stimuli. We then redesigned the shape of the small bumps, and evaluated the design in a second experiment. The results indicated that the best shape to present haptic stimuli is a right triangle cross section in both the ascending and descending cases. Although it is necessary to install small protrusions in the determined direction, by using this optimized shape the users feeling of presence of the stairs and the sensation of walking up and down was enhanced. [ABSTRACT FROM PUBLISHER]

In order to verify the influence of seismic isolation rubber supports and polytetrafluoroethane plate sliding supports at the lower part of the stairway slabs on the seismic performance of cast-in-place reinforced concrete (RC) slab-stairs, the shaking table test of a 1/3 scaled RC staircase frame unit model structure was conducted to observe the failure process, and to analyze the natural vibration frequency variation, acceleration response, displacement response and failure mechanism by inputting motions of different intensities. Experimental results indicate that staircase unit with seismic isolation rubber supports at the lower part of the stairway slabs has excellent seismic performance and the failure is concentrated at main structure under rare earthquake input, which releases bracing effect of the stairway slabs effectively and realizes that substructure fails seriously later than main structure. When ploytetrafluoroethene plate sliding support is used at the lower part of the stairway slabs, severe vertical deformation and horizontal sway occur in the resonance destruction test. However, when seismic isolation rubber support is used at the lower part of the stairway slabs, vertical acceleration of staircase slabs is decreased, no sway occurs in the resonance destruction test. [ABSTRACT FROM AUTHOR]

People acting on a slender structure can affect the dynamic behaviour of the structure they occupy, in addition to being a source of forcing. In such cases, the use of the dynamic properties of the empty structure to estimate the structural response can lead to an erroneous estimation of the amplitudes of vibration. This work proposes an approach to improve the prediction of the structural response due to the presence of people. The method is based on the identification of an equivalent set of frequency response functions to represent the dynamic behaviour of the joint structure-moving people system. The method starts from the modal model of the empty structure, i.e., natural frequencies, damping ratios and mode shapes. No restriction on the number of degrees of freedom of the structure is required. Each subject is modelled through an equivalent apparent mass and is introduced on the model of the empty structure to obtain a model of the joint structure-moving people system. An active force is then applied to the equivalent model to obtain a prediction of vibration levels. The effectiveness of the approach was verified through experimental tests performed in controlled conditions. Two lightly damped steel staircases were used as test cases. A comparison between the amplitudes of the measured vibration and those predicted using the proposed methodology is presented. The results show that the use of the empty structure model can lead to a high overestimation of the vibration amplitudes. Conversely, the results obtained with the proposed approach are in agreement with the experimental data. [ABSTRACT FROM AUTHOR]

In order to study the seismic performance of the staircase in the cast-in-place reinforced concrete frame, a 1/2 scaled specimen of the structural unit composed of concrete frame and staircase was tested quasi-statically. The test demonstrated the failure mode and mechanism of the structural unit as a whole and those of its various components, and the load-carrying capacity, displacements and other aspects related to seismic behavior were also measured. The test shows that, when fully connected to the main structure with the conventional manner of construction, the staircase works as asymmetrically inclined bracings in the structure, resulting in its early cracking and fast damaging, and consequently, its functions, such as seismic rescue and evacuation, could not be ensured; meanwhile, it also causes irregular forces of the frame members, leading to the brittle failure of the column in one side of frame and then the complete failure of the specimen. The enclosed area of hysteretic loop of the specimen is relatively small and its peak value of load reaches high but, after that, the capacity decreases fast. The rigid connection between the frame column and the supporting beam of the stair platform on the half story makes some frame columns, which are already in complex state of loading, the short columns, leading to the local collapse of such column and failure in other parts of the frame suddenly. Therefore, the staircase connected to the concrete frame with such a conventional manner as mentioned above is adverse to seismic resistance of the structure. [ABSTRACT FROM AUTHOR]

A new measure, in which sliding supports are used between the staircases and the main structure, is proposed in the current code for seismic design of buildings. To experimentally verify the new measure, the shaking table test of a large scaled structural unit of concrete frame-staircase with sliding supports made of ploytetrafluoroethene ( PTFE ) plate was conducted to dynamically test its performance under input motions of different intensities. It shows that, with the sliding supports at the lower end of the stairway slabs, the seismic behavior of the structural unit of concrete frame-staircase is satisfactory; even subjected to very severe motions, serious damages happen mainly in the members of concrete frame and no serious failure occurs earlier than the frame in the staircase parts, including stairway slabs, platform, supporting beams and columns; the sliding support made of PTFE plate works effectively and, horizontally along the direction of the input motions, the lower ends of the stairway slabs can slide back and forth as expected; meanwhile, they also have repeated up and down movements there. [ABSTRACT FROM AUTHOR]

A multi-storey building is habitually modelled as a frame structure which neglects the shear wall/slab openings along with the inclusion of staircases. Furthermore, the structural strength provided by shear walls and slabs is not precisely incorporated. With increasing building height, the effect of lateral loads on a high-rise structure increases substantially. Inclusion of shear walls and slabs with the frame leads to improved lateral stiffness. Besides, their openings may play imperative role in the structural behaviour of such buildings. In this study, 61 multi-storey building configurations have been modelled. Corresponding analyses are performed to cope with the influence of shear walls, slabs, wall openings, masonry walls and staircases in addition to frame modelling. The finite element approach is used in modelling and analysis. Structural responses in each elemental combination are evaluated through equivalent static and free vibration analyses. The assessment reveals that inclusion of only slab components with frame modelling contributes trivial improvement on structural performance. Conversely, the presence of shear wall slabs with frame improves the performance noticeably. Increasing wall openings decreases the structural responses. Furthermore, it is not recommended to model staircases in addition to frame–slab–shear wall modelling, unless the effect of wall openings and slab openings is adequately considered. [ABSTRACT FROM PUBLISHER]

Highlights: [•] We examined temporospatial, lower limb kinematics in staircase descent. [•] We looked at 3 different angles of descent down a staircase. [•] Adaptations at an angle were mainly seen in step width, length. [•] Stance, swing, and double support phase proportions were unchanged. [•] Older adults may have an issue with performing these adaptations. [Copyright &y& Elsevier]

Abstract: Chinese fire prevention codes provided that pressurized ventilation system should be used in the staircase which can not exhaust fire smoke naturally. However, the codes only specified the specific parts of pressurized ventilation and ventilation volume, while they did not specify how to make the pressurized ventilation effective in particular cases. As a result, in engineering application, some staircase pressurized ventilation systems can not effectively prevent smoke entering the staircase. For instance, in a staircase where the pressurized ventilation system must be used according to the codes, opened windows were set in the wall of the staircase so as to facilitate lighting and ventilation. Although that conforms to the codes, the effect of preventing smoke invasion is still unknown. This simulation study focused on the influence of opened windows on the pressurized ventilation system. It was found that if there were no open windows in the staircase, the system worked. At the same time, smoke would flow into the staircase in a short time and the high temperature was fatal to the evacuees if there were opened windows on the wall of this space. These results indicated that opened windows in the staircase would lead to uselessness of the pressurized ventilation system. In conclusion, it was suggested there are no windows in the staircase in which a pressurized ventilation system should be used. And if windows are necessary in the pressurized staircase for light, the windows should be fixed casement windows. [Copyright &y& Elsevier]

Abstract: With the rapid development in economics, subway systems have been constructed in many big cities of China. Computer evacuation models developed overseas are commonly applied in working out safety management scheme. However, input evacuation parameters are not compiled from surveying passenger behavior in China. In fact, very few studies were conducted on justifying such parameters. Staircases in subway stations, particularly those connecting the platform and the ticket hall, are identified as the ‘bottleneck’ during evacuation in the subway stations. The maximum upstairs speed and the average minimum width of staircase utilized per person are the two key parameters affecting the evacuation through the staircase. Effect of varying these two parameters will be studied in this paper by taking two subway stations in China as examples. Evacuation performance is predicted with the software buildingEXODUS. The default values in the software are used and adjusted through field survey. Effect of varying either or both of the two parameters is discussed. The possible causes on the differences and the factors to affect such effect are explored. It is found that changing both parameters simultaneously would reduce the overall evacuation time by 50%. The effect of varying the two parameters on the overall evacuation performance of the whole station depends also on the occupancy density in the station; and the travel distance from the outlet of the staircase between the platform and the ticket hall to the inlet of the staircase between the ticket hall and the ground surface. [Copyright &y& Elsevier]

Abstract: In this article, the unidirectional transport of the inertial ratchet is presented. We observe that in the ratchet, there is positive, negative or even no current. Moreover, the structure of staircases of the ratchet is argued and we observe that it becomes more regular as the damping coefficient is increased. [Copyright &y& Elsevier]

Abstract: Crowding during the morning peak hours at a platform staircase in a subway station in China was studied in this paper. Passenger flow was surveyed with normal evacuation time recorded. The evacuation process was simulated with the software buildingEXODUS. Predicted results on the total evacuation time and maximum flow capacity of the selected staircase were compared with the field observations. Two parameters, the width of staircase utilized per person and the maximum upstairs walking speed used in the software were identified to be noticeably different from the field studies. Predictions agreed better with the observations after tuning these two parameters. It is concluded that the evacuation simulation software can be applied for safety design with appropriate tuning on the key parameters through field tests. [Copyright &y& Elsevier]

• Fatigue limit estimation of automotive crankshafts using the Thermographic Method. • Tests on dog-bone specimens and automotive crankshaft samples. • Correlation of results with the Wöhler curve and Staircase procedures. • New strategy for data reduction and analysis. The determination of the fatigue behavior at a component level usually requires dedicated test rigs and an expressive amount of time. The hours spent on such machinery are expensive; therefore, solutions to reduce experimentation time are most welcomed. In this context, this investigation aims at developing a procedure for rapid determination of the fatigue strength of crankshafts by means of a thermographic methodology. The use of infrared cameras for fatigue strength analysis was first assessed in standard dog-bone specimens. Crankshafts were then tested in an in-house fatigue test rig using the conventional staircase method and the thermographic method. Sample batches with different manufacturing parameters were produced and tested to assess the robustness of the proposed alternative technique. Results of the dog-bone test campaign revealed a good correlation between fatigue strength estimates obtained with the conventional Wöhler curve and the thermographic methodology. Finally, the thermographic technique also delivered results in close agreement with the staircase method for all crankshaft batches. The proposed procedure was found to be a viable, rapid alternative to conventional fatigue test programs, with potential application for complex structural components such as crankshafts, among others. [ABSTRACT FROM AUTHOR]

Abstract: Static non-linearity tests on ADCs take many hours to complete, especially when they are of high-resolution, say, 10-bits or more. Efforts to reduce this test time have been attempted, but suggested methods are either not suitable for high-speed high-resolution ADCs or deviate from procedures given in relevant standards, viz. IEC 61083-1, IEEE 1057 or IEEE 1241. In this paper, a novel method is proposed to test such ADCs. It is simple, easy to implement, requires less time and does not impose any change to relevant standards. Instead of the conventional method of applying one DC waveform at a time to the ADC, the proposed method involves application of several DC waveforms (say, 32 or 64) at once, configured as a staircase waveform. Many staircases are used to cover the input voltage range. Thus, in a single acquisition, information corresponding to several DC waveform applications is generated. Hence, a reduction in test time is achieved. Generation of these staircases is straightforward using an arbitrary waveform generator. The timesavings achieved from this method depend on available memory and waveform uploading speed of the arbitrary waveform generator. [Copyright &y& Elsevier]

The aim of the study was to compare the outcomes for the fatigue mechanical behavior of bonded simplified lithium disilicate restorations, with and without an internal adjustment by grinding with diamond bur in running two fatigue tests: Staircase and Step-stress testing approaches. Ceramic discs (IPS e.max CAD) were prepared (Ø = 10 mm; thickness = 1.0 mm), submitted to an in-lab simulation of CAD/CAM milling (#60 SiC paper) and allocated into 2 groups according to the internal adjustment by grinding of the cementation surface: no adjustment (CTRL); or grinding with a coarse diamond bur (GR). Adhesive cementation (Multilink N) was performed onto epoxy resin discs (Ø = 10 mm; thickness = 2 mm) after ceramic/epoxy surface treatments. The cemented assemblies of each group were randomly assigned into 2 subgroups considering two fatigue tests (n = 15): Staircase – SC (250,000 cycles; 20 Hz), or Step-stress – SS (10,000 cycles per step; 20 Hz). Roughness, topographic and fractographic analyses were additionally performed. Statistical analyses were carried out using the Dixon and Mood method for Staircase data, and Kaplan–Meier and Mantel-Cox (log-rank) tests for Step-stress data. Ceramic restorations having its intaglio surface ground (GR group: SC test = 306.67 N; SS test = 646.67 N) presented lower fatigue failure load (FFL) values than the CTRL group (SC test = 879.28 N; SS test = 1090.00 N), regardless of the fatigue testing approach. The percentage of mean FFL decrease comparing the CTRL to GR group was higher for SC (65.1%) than the SS (40.7%) approach. However, a different total number of cycles was applied for each method. Both fatigue tests were able to detect the negative effect of internal adjustments of lithium disilicate glass-ceramic simplified restorations on their mechanical behavior. Therefore, both methods can be applied for similar evaluations (fatigue testing for ceramic restorations). • Both fatigue tests detected that internal adjustments decreased the fatigue behavior. • Staircase or Step-stress fatigue tests can be applied for similar evaluations. • Fatigue test parameters may have influenced the percentage of failure load decrease. [ABSTRACT FROM AUTHOR]

Designing or analysing the influence of fatigue on concrete structures is becoming increasingly important for a number of structural elements. For this reason, it is necessary to define a method capable of determining the concrete's fatigue limit in the most economical, fast and efficient way. The aim of this study is to compare and correlate different methods found in the literature in order to reduce the number and duration of the tests required to determine the fatigue limit. This reduction will consequently reduce the economic costs of determining the fatigue limit. For these proposes three different types of self-compacting recycled concrete was used. A linear correlation was found between the analysed methods, which means that the methods are capable of providing similar results and that the results obtained by the economical procedure must be selected. This work opens the door to define an optimal procedure in the process of concrete fatigue characterization, which is capable of yielding results up to five times faster and more economical than with other methodologies, so that resources are not wasted. • Locati and Staircase method provide similar fatigue limit in high frequency fatigue. • A drop in the resonance frequency means an increased damage. • 2 × 105 cycles per Locati step are enough to determine the fatigue limit. [ABSTRACT FROM AUTHOR]

• Local architectural cues are seen as salient landmarks. • Staircases enable vertical circulation in multi-level buildings. • Staircase attributes influence virtual vertical navigation behavior. • Virtual navigation and individual differences affect staircase preferences. • Interior design heuristics are provided for staircases. Architectural design requires experiencing the spatial organization of a building, discovering architectural cues and maintaining spatial orientation during navigation. Architects configure architectural cues in the initial phase of the design process. Staircases, as a feature of local architectural cues that provide access to the other floors in a multi-level building, can have an impact on vertical navigation and aid individuals during navigation and influence their spatial orientation. This study focuses on the issue of vertical navigation during virtual navigation by integrating the individual differences and the geometric attributes of a staircase pair within two different multi-level desktop virtual environments (VEs). The angle between the cue pairs with respect to the same observation point is altered in order to determine the staircase pair that is more efficient in navigation. Virtual vertical navigation is based on an egocentric frame of reference where the participants have control of their movements. Circulation paths, gender differences, navigational abilities and cue pairs are the factors that affect staircase preferences for ascending and descending. For the VE with a 180° difference between the cue pairs, a relationship was found between the ascending and descending staircases. Further analysis indicated that the staircase preference in ascending was either related to the first or last visited rooms on the ground floor. For the VE with a 90° difference between the cue pairs, no relationship was found between the ascending and descending staircases as well as with any other factor. There was only a significant relationship between gender and staircase preference in descending staircases with 180° difference between the cue pairs in favor of females. In addition, there was no significant relationship between the navigational abilities and staircase preferences. [ABSTRACT FROM AUTHOR]