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Roadway tunnels often include a reinforced concrete drop ceiling that is hung from the liner to create a plenum that facilitates ventilation and houses utilities. Drop ceiling panels are lightweight compared with the much thicker tunnel liner and can experience significant damage from a fire on the roadway below. This paper examines the flexural response of drop ceiling panels in two representative tunnels to standard fire curves as well as several realistic fires due to vehicular accidents. Standard fire demands as per the Rijkswaterstaat and ASTM E1529 fire curves are uniformly applied to the ceiling panels, and heat exposure contours for typical vehicle fires with heat release rates of 30, 100, and 200 MW are generated from the software CFAST. The finite element analysis software SAFIR is used to evaluate the thermo-mechanical behavior of the ceiling panels when subjected to various thermal demands from the fire below. The analysis results indicate that drop ceiling panels are highly vulnerable to fire-induced damage and potential collapse both during a fire’s active heating phase (from simultaneous loss of capacity and restraint of thermal expansion) and during the subsequent cooling period (from tension that develops when the permanently deformed panel thermally retracts). The potential for fire-induced damage or collapse of the drop ceiling panels can be mitigated by reducing the fire hazard, removing the drop ceiling, or enhancing the fire resistance of the panels via the application of passive protection or structural hardening.

Ceiling fans are the most common equipment in any household with electricity to induce a higher air movement since the potential of natural ventilation is limited. However, the higher airflow region is generally limited to the zone below the fan. The non-uniform distribution of airflow is also affected by the furniture layout and airflow from window openings. This study attempts to evaluate the effect of the different window-opening patterns on the airflow inside naturally ventilated bedrooms, having a ceiling fan for air movement with numerical simulations and on-site measurements. The airflow pattern created by a ceiling fan in a room with furniture is modelled and simulated with ANSYS Fluent 2019 R3. The results were validated with on-site measurements and compared with the literature. The air velocity was measured in bedrooms of three different sizes. It was observed that the opening of windows created a better distribution of air irrespective of room size. The non-uniformity of the air velocity is reduced from 76% to 39% with the opening of windows in the larger-sized room. The reduction in non-uniformity is influenced by the location of windows also. The practice of opening windows along with the induced air movement by ceiling fans results in a better distribution of air in the space. Practical application: People tend to depend mainly on ceiling fans even if windows are open in naturally ventilated rooms. A study of patterns of non-uniform distribution of airflow can help designers to improve comfort conditions by specifying the number and location of fans and windows while designing room furniture layout. This aids the building services engineers to provide thermal comfort without always depending on alternative active ventilation strategies.

Nursing is often associated with providing working-class women a route to upward social mobility. This article argues that although nursing is a relatively open profession, the impact of social class endures, with the main division between nurses who are from higher professional backgrounds and the rest. We utilise the Great British Class Survey (GBCS) to explore nurses’ social origins; the relationship between background and economic, social, and cultural capital; and the impact of origin and capitals on income (and inferred career trajectory). While recognising the methodological limitations of the GBCS, we suggest there may be a ‘class ceiling’ in nursing, and that class advantages are still significant in lower professions of the public sector. Class identification endures regardless of whether nurses have been upwardly or downwardly mobile. We also suggest future directions for intragenerational mobility and gender in social mobility research and make a case for longitudinal and qualitative analysis of nurses’ trajectories. Our findings indicate that the downwardly mobile children of the middle classes retain their classed advantages as they establish their own careers.

Cool roofs with higher solar reflectance and emittance can effectively reduce building energy consumption. However, it is still limited to use at night on account of the development of roof materials during the past decades. The newly proposed metamaterial-based cool roof (MCR) greatly improves the possibility of the radiative cooling in the daytime. To study the influence of MCR on the energy consumption for the office building, a small single-floor office was adopted to analyse the cooling performance of MCR by using EnergyPlus. In this study, the optimization analysis was conducted based on the proposed dimensionless thermal resistance ( θRTR) and roof pitch (Δ). Then the annual electricity saving potential of the office building with MCR was evaluated in details based on the selected cities from all five climate zones in China. The results show that more annual electricity saving can be achieved under the optimized values of θR7 = 1.53 and Δ = 20°. Furthermore, more than 15.7% of annual cooling electricity saving can be achieved while the optimized θRTR and Δ are applied.

The heat radiation in a residential kitchen was simulated by CFD (Computational-fluid-dynamics) to evaluate the cooling by a radiant cooling ceiling panel and pollution dispersion by the range hood and the air extraction system. The kitchen has a 2-hobs stove and a fume hood for removing waste heat and fumes. The simulation was validated by measurements in a domestic kitchen in a home in Changsha, China, where summer temperature is generally about 33 °C and often over 35–42°C. The simulation results show that the pollutant concentration in the kitchen during cooking was much lower than the Chinese standard criteria of GB/T18883-2002. A standard turbulence model was used, which indicated satisfactory distribution of temperature and airflow in the kitchen. The indoor airflow velocity was low. The airflow temperature when both hobs were used was slightly higher by 3–4°C than when a single hob was used. The temperature in the kitchen during cooking was about 28 °C, which was a degree lower than the living-room temperature, thus maintaining a comfortable thermal and healthy environment. The radiant cooling in the ceiling was shown to be a significant contributing factor. The ring suction type range hood has a sufficient capacity to remove the kitchen fume contaminants.

In this article we demonstrate that those from working-class backgrounds face a powerful ‘class ceiling’ in elite occupations. Examining how class origin shapes economic returns in the Norwegian upper class (3.8% of the population), we first find that the income advantage enjoyed by those from privileged backgrounds increases sharply as they ascend the income distribution in both elite business and cultural fields. Second, we show that those from economically upper-class backgrounds enjoy the highest pay advantage in all upper-class destinations. Finally, we demonstrate the profound propulsive power provided by parental wealth. Our results indicate that this is the most important single driver of the class-origin income gap in virtually every area of the Norwegian upper class. These findings move forward an emerging literature on class-origin pay gaps beyond mean estimates to reveal the distinct ‘pay-off’ to class privilege in the very highest income-earning positions.

A mixing ventilation system integrated with a ceiling cooling system is a potential advanced heating, ventilation and air conditioning system for modern office buildings with a high sensible cooling load. This paper presents an evaluation of the effect of sensible cooling load on the indoor air distribution in a typical office room with mixing ventilation and ceiling cooling. The vertical distributions of indoor air temperature, air velocity and contaminant (CO2) concentration were evaluated by the vertical air temperature difference, turbulence intensity and contaminant removal effectiveness. The results showed that when the chilled ceiling surface temperature was increased from 15.0°C to 23.0°C and supply air temperature was decreased from 22.0°C to 19.0°C, the average vertical air temperature difference, turbulence intensity and contaminant removal effectiveness were 0.2°C–0.3°C, 27%–32% and 0.53–0.81 as both internal and external sensible cooling loads were 41.5 W/m2. Moreover, these evaluation indices varied slightly as the external sensible cooling load was increased from 41.5 W/m2 to 69.5 W/m2, whereas they varied greatly as the internal sensible cooling load was increased from 41.5 W/m2 to 69.5 W/m2. Hence, the external sensible cooling load could slightly affect the indoor air distribution, whereas the internal sensible cooling load could clearly affect the indoor air distribution in an office room with mixing ventilation and ceiling cooling.

Previously published hot-box data have been used to construct equations for the thermal resistance of enclosed reflective air spaces (reflective insulation assemblies) for a wide range of temperatures, air gap dimensions, thermal emittances, and heat flow directions. The thermal resistances or R-values (RSI) calculated with the equations compare favorably with previously published thermal resistances. Significant differences from RSI values (m2 K/W) calculated using ISO 6946 were observed. Equations for calculating heat transfer coefficients for conduction–convection with constants for the heat flow directions up, 45° up, horizontal, 45° down, and down are contained in this article. The conduction–convection coefficient for planar air spaces oriented at any angle and heated above can be obtained by interpolation between heat flow down and heat flow at a downward angle of 45° or heat flow down at an angle of 45° and horizontal heat flow. The overall heat transfer coefficient is obtained by adding the thermal radiation contribution to the conduction–convection contribution. The RSI of enclosed reflective air spaces is the reciprocal of the overall heat transfer coefficient for the air space. This air space RSI is especially useful as input for the calculation of U-values for ceiling–roof assemblies located in hot climates.

A new experimental methodology is presented to show the effect of water supply temperature, mass flow rate and thermal load distribution on the radiant ceiling capacity and thermal comfort conditions. Computerized fluid dynamics simulated vertical temperatures and velocities profiles were validated by a comparison with experimental results and the difference was within 10%. Uniform surface temperature distribution was achieved in a 45.6 m3 test room installed with capillary ceiling radiant cooling panels by an increase in water temperature and air supply velocity. When the ventilation system was turned off, the mean ceiling surface temperature rose from 16.9 ± 0.4°C to 21.5 ± 0.3°C with a rise in the inlet water temperature to 20.1°C. The temperature difference between the head and ankle of an occupant was 2.0°C, which complies with the Chinese standard, GB/T 18049-2017. At a height of 1–1.5 m, the maximum temperature fluctuation was 2°C in the horizontal direction. When the ventilation system was turned on, with the air supply temperature and velocity at 19.8°C and 1.11 m s−1, the ceiling surface temperature was increased by 0.5°C. The indoor air temperature has a positive correlation with the air supply temperature and internal heat load but a negative correlation with air supply velocity.

The influence of occupants'’ movements should be considered when analysing local thermal comfort. This study presents the effect of human movement on airflow characteristics and local thermal conditions with diffuse ceiling ventilation by experimental studies. A simulated person moving was used to study the human movement in an office. In these experiments, three moving speeds were studied: 0.3, 0.6 and 1.0 m/s. The simulated person moved in four cycle patterns: continuous moving and with 5 s, 10 s and 15 s interval breaks between each turn. Three heat gain levels of 40, 60 and 80 W/m2were evaluated in the chamber. The results indicate that the human movement decreased vertical temperature gradient compared with the steady-state condition. Instead, the moving intervals would have no effect on the vertical air temperature gradient. The power spectral density was increased by 90% due to the person movement compared with the steady-state condition. The moving person would create different micro-environments close to work stations than close to the moving area.

The purpose of this study was to determine the intra- and inter-rater reliability of scoring procedures used in the newly developed Basketball Jump Shooting Accuracy Test (BJSAT) and assess for flo...

It is often assumed that reduced heat flux to a ventilated attic reduces the temperatureand thereby increases the relative humidity. Consequently, the importance of having atight air and vapour barrier in the ceiling becomes more important with increased insu-lation. Therefore, in Denmark, the recommendation is to have a tight vapour barrierwhen re-insulating ceilings against cold ventilated attics to a total of 150-mm insulationmaterial. The recommendation is independent of the insulation material’s hygroscopicproperties or the indoor moisture level. The aim of this project was to test the rele-vance of the recommendation through testing in a full-scale test building (7322 m) witha series of six different ceilings with or without a vapour barrier and variation in theinsulation material comprising insulation thickness and its hygroscopic properties. Theexamination was performed with a controlled indoor climate after an European humid-ity classes 1–3 and a natural outdoor climate. The study showed very little differencesin temperature and relative humidity in the cold ventilated attics, while the humidityclass of the indoor climate significantly affects the absolute moisture content in the attic.However, the climate in the attic did not cause mould growth in the test sections, evenfor humidity class 3. Consequently, in the test building the thickness or hygroscopic1Danish Building Research Institute, Aalborg University Copenhagen, Copenhagen, Denmark2Department of Mathematical Sciences, Aalborg University, Aalborg, DenmarkCorresponding author:Thor Hansen, Danish Building Research Institute, Aalborg University Copenhagen, A.C. Meyers Vænge 15,2450 Copenhagen, Denmark.Email: thh@sbi.aau.dkproperties of the insulation material did not have a significant effect on the moisturelevel in attics and did not determine whether a vapour barrier should be installed. In thisstudy with the given climate, a vapour barrier is unnecessary in well-ventilated attics ifthe ceiling is airtight. It is often assumed that reduced heat flux to a ventilated attic reduces the temperatureand thereby increases the relative humidity. Consequently, the importance of having atight air and vapour barrier in the ceiling becomes more important with increased insu-lation. Therefore, in Denmark, the recommendation is to have a tight vapour barrierwhen re-insulating ceilings against cold ventilated attics to a total of 150-mm insulationmaterial. The recommendation is independent of the insulation material’s hygroscopicproperties or the indoor moisture level. The aim of this project was to test the rele-vance of the recommendation through testing in a full-scale test building (7322 m) witha series of six different ceilings with or without a vapour barrier and variation in theinsulation material comprising insulation thickness and its hygroscopic properties. Theexamination was performed with a controlled indoor climate after an European humid-ity classes 1–3 and a natural outdoor climate. The study showed very little differencesin temperature and relative humidity in the cold ventilated attics, while the humidityclass of the indoor climate significantly affects the absolute moisture content in the attic.However, the climate in the attic did not cause mould growth in the test sections, evenfor humidity class 3. Consequently, in the test building the thickness or hygroscopic1Danish Building Research Institute, Aalborg University Copenhagen, Copenhagen, Denmark2Department of Mathematical Sciences, Aalborg University, Aalborg, DenmarkCorresponding author:Thor Hansen, Danish Building Research Institute, Aalborg University Copenhagen, A.C. Meyers Vænge 15,2450 Copenhagen, Denmark.Email: thh@sbi.aau.dkproperties of the insulation material did not have a significant effect on the moisturelevel in attics and did not determine whether a vapour barrier should be installed. In thisstudy with the given climate, a vapour barrier is unnecessary in well-ventilated attics ifthe ceiling is airtight.

Ceiling fans have been widely used as effective cooling and air mixing method for building environment conditioning. Understanding its airflow characteristics can be helpful to utilize ceiling fan or integrate it with background air conditioning system. However, the airflow induced by ceiling fan has different flow patterns under different rotating speeds and blowing directions. To date, it is still challenging to capture those complicated airflow fields in room scale. In this study, the airflow pattern induced by a ceiling fan was measured with a new technology, quad-view colour sequence particle streak velocimetry. A series of isothermal experiments were conducted under five rotation speed levels with downward and upward blowing directions in a room-size (4 m × 2.5 m × 3 m) chamber. Based on comprehensive three-dimensional three-component vector measurement results, the average velocity, turbulence intensity and vorticity on the middle section were calculated and used to analyse airflow patterns induced by ceiling fan. The results show that the blowing direction of the fan determines the indoor airflow pattern. When blowing downward, the flow will cause high diversion between jet core under the fan blades and surrounding region. While for upward blowing, the air speed in lower part of the room is much lower but pretty uniform. The detailed measured airflow fields can serve as reference for ceiling fan design and operation.

An underfloor air distribution (UFAD) system integrated with a chilled ceiling (CC) cooling system may be a potential advanced heating, ventilation and air conditioning system in modern non-residential buildings with high sensible cooling loads. This article presents an experimental study concerning the effect of ceiling surface temperature and supply air velocity on the indoor air distribution in a room with UFAD as the internal and external sensible cooling loads change. The vertical distributions of indoor air temperature, air velocity and contaminant (CO2) concentration were evaluated by vertical air temperature difference (VATD), turbulence intensity (TI) and contaminant removal effectiveness (CRE), respectively. The results showed that the average VATD, TI and CRE levels were 0.5°C–1.0°C, 31%–41% and 0.85–1.06 when both internal and external sensible cooling loads were 41.5 W/m2. These evaluation indices varied clearly when the external sensible cooling load increased from 41.5 W/m2 to 69.5 W/m2, whereas they remained almost the same when the internal sensible cooling load increased from 41.5 W/m2 to 69.5 W/m2. The maximum TI coincided with the minimum CRE under the condition of a constant sensible cooling load. Moreover, an air diffusion performance index clearly reduced with an increase in the heat removal effectiveness. It is recommended that it is important to balance the indoor air quality and energy consumption in a room with UFAD + CC.

Human observers readily detect targets in stimuli presented briefly and in rapid succession. Here, we show that even without predefined targets, humans can spot repetitions in streams of thousands of images. We presented sequences of natural images reoccurring a number of times interleaved with either one or two distractors, and we asked participants to detect the repetitions and to identify the repeated images after a delay that could last for minutes. Performance improved with the number of repeated-image presentations up to a ceiling around seven repetitions and was above chance even after only two to three presentations. The task was easiest for slow streams; performance dropped with increasing image-presentation rate but stabilized above 15 Hz and remained well above chance even at 120 Hz. To summarize, we reveal that the human brain has an impressive capacity to detect repetitions in rapid-serial-visual-presentation streams and to remember repeated images over a time course of minutes.

Under air-conditioning intermittent operation, there may be the large difference of air temperatures in two adjacent rooms due to different operation behavior, and thereby, interior envelops may cause great heat loss. Under this condition, floors may become the most vulnerable spot of the room heat preservation due to their large proportion in interior envelops and poor thermal insulation. To optimize the thermal performance of floors, three floor models were built to compare their thermal performance characteristics under air-conditioning intermittent operation, while a heat transfer model was built by the finite volume method and verified by experimental data. The results showed that an expanded polystyrene layer located close to the upper surface can improve the thermal performance of the bottom floor, while the continuous integration of an air space ceiling placed close to the lower surface can improve the thermal performance of the top floor obviously. The daily cooling load formed by the cast-in-place-reinforced concrete floor integrated with the expanded polystyrene layer and the air space ceiling can reduce the daily cooling load by 53.27% and 47.00%, compared with the cast-in-place-reinforced concrete floor and the cast-in-place-reinforced concrete floor only integrated with the expanded polystyrene layer.

According to Pozsar, there is a new kind of “Triffin Dilemma.” Due to rising inequality, a shrinking numbers of large banks, and a ceiling on Federal Deposit Insurance Corporation (FDIC) insured deposits, there is a shortage of “safe assets.” The private supply of safe assets has occurred through the system of shadow banks, and is based on repos, or Treasury Bonds. But the supply of US Treasury bonds is limited by the ceiling on public debt, and is constrained by neoliberal theories of limits to the size of government. As a result, there is a presumed shortage of safe assets, just when the levels of inequality have increased the order of magnitude of assets under management which are in need of protection. There are also large accumulations of cash pools by large multinational corporations, often held overseas to evade taxes. The private provision of safe assets tends to reduce liquidity and increase costs of information, potentially leading to financial instability. Possible resolutions of this issue include (1) progressive taxes to reduce the size of the cash pools, (2) an increase in the ceiling for insured deposits, and (3) increasing support by the Fed for the role of “market maker of last resort.” This paper concludes with the implications of each alternative. JEL Classification: B5, E44, G01, P1

The capillary ceiling radiation cooling panel (C-CRCP) is a newly developed terminal device for air conditioning to provide indoor thermal comfort for occupants and to save energy. In this paper, numerical modelling of a room with a C-CRCP system was used to analyze radiant heat transfer under non-steady-state conditions. Experiments were conducted in an environmental chamber to verify simulation results. The chamber was equipped with a C-CRCP, which was covered with gypsumboard. The results showed that the inlet water temperature had a significant influence on ceiling surface temperature. The ceiling surface temperature and the steady-state time were increased with higher inlet water temperature. A vertical gradient in indoor air temperature was found. Ceiling surface temperature and indoor air temperature were increased with an increase in inlet air temperature. The energy supply rate of the radiant panel had a positive correlation with chilled water velocity. The amount of radiation was double the amount of convection, and the thickness of the gypsumboard had virtually no effect on the proportions of radiation and convection. The model was considered validated since the maximum relative errors between experimental data and simulation results of inlet water temperature and supply air conditions were within 10%.

This is a basic review of how to bin variables in Stata, meaning how to divide their range or support into disjoint intervals. I survey rounding functions with emphasis on floor and ceiling functions as tools to get clearly defined intervals of equal width. Using a specific display format is usually a better idea than rounding to multiples of a fraction. Quantile binning is popular in several fields. I give tips and tricks on how to produce such bins and also on how to show their limitations. Experimentation with the display command or Mata is a good way to learn about functions and to test binning rules.

Objective:We investigate effects of the hue, saturation, and luminance of ceiling color on the perceived height of interior spaces.Background:Previous studies have reported that the perceived height of an interior space is influenced by the luminance of the ceiling, but not by the luminance contrast between ceiling and walls: brighter ceilings appeared higher than darker ceilings, irrespective of wall and floor luminance. However, these studies used solely achromatic colors. We report an experiment in which we extend these findings to effects of chromatic ceiling colors.Methods:We presented stereoscopic room simulations on a head-mounted display (Oculus Rift DK2) and varied hue (red, green, blue), saturation (low, high), and luminance (bright, dark) of the ceiling independently of each other.Results:We found the previously reported ceiling luminance effect to apply also to chromatic colors: subjects judged brighter ceilings to be higher than darker ceilings. The remaining color dimensions merely had a very small (hue) or virtually no effect (saturation) on perceived height.Conclusion:In order to maximize the perceived height of an interior space, we suggest painting the ceiling in the brightest possible color. The hue and saturation of the paint are only of minor importance.Application:The present study improves the empirical basis for interior design guidelines regarding effects of surface color on the perceived layout of interior spaces.

People differ in how quickly they learn information and how long they remember it, yet individual differences in learning abilities within healthy adults have been relatively neglected. In two studies, we examined the relation between learning rate and subsequent retention using a new foreign-language paired-associates task (the learning-efficiency task), which was designed to eliminate ceiling effects that often accompany standardized tests of learning and memory in healthy adults. A key finding was that quicker learners were also more durable learners (i.e., exhibited better retention across a delay), despite studying the material for less time. Additionally, measures of learning and memory from this task were reliable in Study 1 ( N = 281) across 30 hr and Study 2 ( N = 92; follow-up n = 46) across 3 years. We conclude that people vary in how efficiently they learn, and we describe a reliable and valid method for assessing learning efficiency within healthy adults.

The article provides the empirical framework and steps toward the evaluation of the spatial consequence of the 17% interest rate ceiling in Arkansas using a new database from the trade association for installment lenders, the American Financial Services Association. The specific contribution of this study is to build and apply the installment loan accessibility index within the context of the spatial regime models. Results suggest strong evidence of spatial clustering of counties with similar (low or high) installment loan usage rates across the study area and two spatial regimes at work. The loan accessibility index is a strong predictor of the installment loan usage in the study area. That is, an increase in the loan acquisition costs due to the 17% interest rate cap puts interior counties’ residents at disadvantage compared with residents of border counties who can cross the borders to get small dollar loans. JEL Classifications: C51, C52, G23, G28

Full scale shake table testing is conducted on a novel type of suspended ceiling called fully floating ceiling system, which is freely hung from the floor above lacking any lateral bracing and connections with the perimeters. A gap is provided on all sides of the ceiling. Throughout different tests, a satisfactory agreement between the fully floating ceiling response and simple pendulum theory was demonstrated. When subjected to input motions with significant energy in the floating ceiling's resonant frequency, the horizontal displacement of the ceiling exceeded the gap width resulting in pounding induced large acceleration pulses. To mitigate such effects, the perimeter gap fillers of a compressible material are proposed. The addition of perimeter isolation was found effective in inducing extra damping and protecting the ceiling from pounding impact; resulting in much reduced ceiling displacements and accelerations. Throughout the tests a single panel dislodgement was observed as the only instance of damage.

This article presents data from an exploratory study of the demographic and published scholarship profiles of the deans and university provosts of the top 50 schools of social work as ranked by the 2016 U.S. News and World Report ratings. Method: The authors used an exploratory design to conduct a content analysis of the demographic and scholarship characteristics of the deans and provosts of the 50 top schools of social work. Results: The data show that the majority of deans and provosts of the top 50 schools of social work are Caucasian. The frequency of mentions of African Americans and other ethnically diverse groups in published articles by deans is uneven. Implications: This study highlights recommendations to enhance the opportunities for deanships among racially diverse faculty and to guide further research that explores the reasons for lack of racially diverse candidates selected as deans of schools of social work.

When judging interior space, a dark ceiling is judged to be lower than a light ceiling. The method of metric judgments (e.g., on a centimetre scale) that has typically been used in such tasks may reflect a genuine perceptual effect or it may reflect a cognitively mediated impression. We employed a height-matching method in which perceived ceiling height had to be matched with an adjustable pillar, thus obtaining psychometric functions that allowed for an estimation of the point of subjective equality (PSE) and the difference limen (DL). The height-matching method developed in this paper allows for a direct visual match and does not require metric judgment. It has the added advantage of providing superior precision. Experiment 1 used ceiling heights between 2.90 m and 3.00 m. The PSE proved sensitive to slight changes in perceived ceiling height. The DL was about 3% of the physical ceiling height. Experiment 2 found similar results for lower (2.30 m to 2.50 m) and higher (3.30 m to 3.50 m) ceilings. In Experiment 3, we additionally varied ceiling lightness (light grey vs. dark grey). The height matches showed that the light ceiling appeared significantly higher than the darker ceiling. We therefore attribute the influence of ceiling lightness on perceived ceiling height to a direct perceptual rather than a cognitive effect.

The effect of diluting asbestos stabilizer on its performance of suppressing the asbestos fibre release has been investigated in terms of its penetrability into ceiling materials containing asbestos fibres. The performance of a silicate stabilizer was determined for cases where the ceiling material was damaged by external factors. The higher dilution rate of the stabilizer resulted in lower viscosities and hence greater penetration depths into asbestos ceiling materials. In addition, for cases in which the diluted stabilizer was sprayed several times onto the ceiling materials, the released asbestos fibre concentration was shown to be reduced by approximately 89% compared to the case of damaged ceiling material. Furthermore, this held true in cases where treated ceiling materials were damaged. The optimum condition, considering both performance and efficiency, is for a stabilizer with distilled water to be applied onto the damaged asbestos ceiling materials several times.

Wooden building systems are becoming more common. Still, there are a huge variety of floor assemblies in the market. The floor assemblies normally become the weakest part due to impact load from walking persons. So far, there are no reliable standardized calculation models available regarding prediction of impact sound in the entire frequency range. Therefore, the design is always based upon previous experiences and available measurements. For the development of prediction models, the first approach is to carry out a grouping of various available floor assemblies. From that, the aim is to trace similarities and carry out simplifications. Correlation is found between the single number [Formula: see text] and the mass per unit area. It is also found that the ceiling system is useful in order to optimize the construction. The data will be further processed and used in the model development and to propose optimization of wooden floor assemblies.

The seismic response of suspended ceiling systems that were shaken at the University at Buffalo; University of Nevada, Reno; and E-Defense facilities is critically assessed in this paper. After presenting a brief description of each experiment, the most repetitive damage observations in all experiments are discussed. Fragility curves are developed for ceiling perimeter connectors, supporting elements, and overall performance of ceiling systems by using 346 combinations of ceiling configurations and shake intensities. The key findings of these curves are the insufficient support of the 7/8-in. wall angles, unconservative code design capacity of connections for supporting elements, and early damage of ceiling systems because of ceiling-piping interaction. Acceleration amplification factors of ceiling systems with respect to suspending floor are computed. The amplification factors prescribed by the code were found to be unconservative due to the pounding of panels to the ceiling grids and deck vibration in a vertical direction.

We consider energy-efficient indoor lighting control for adapting to daylight and user presence changes. Light sensors located at ceiling luminaires and at workspace desks are used to provide illumination information feedback, along with user presence information from occupancy sensors at ceiling luminaires, to a lighting controller. The light sensors at the workspace transmit information at a lower update rate than the sensors at the ceiling. Using this sensing information, we propose a control method to adapt the dimming levels of the luminaires such that desired illumination levels are achieved at the workspace level. The performance of the proposed method is evaluated in an office lighting testbed.

In recent earthquakes, the failure of nonstructural elements, including ceiling systems, has resulted in costly damage, inoperable buildings, and endangered lives. Therefore, the need to understand how ceiling systems perform during an earthquake is becoming increasingly important. However, few studies have been conducted on suspension ceiling systems to identify where they are vulnerable. A series of suspension-ceiling component experiments were designed at the University of Nevada, Reno, using interlocking grid members, including 2-ft. and 4-ft. cross tees. The test specimens were first subjected to monotonic and cyclic loading to obtain their failure capacities. Then several axial capacity fragility curves (not the seismic fragility curves of ceiling systems) were developed based on axial displacement capacities as well as strength capacities of interlocking ceiling joints in the absence of ceiling panels. Besides the experimental studies, a series of analytical models for ceiling joints were developed and validated using component experimental data.

In the early twenty-first century, women continue to receive substantially less media coverage than men, despite women’s much increased participation in public life. Media scholars argue that actors in news organizations skew news coverage in favor of men and male-related topics. However, no previous study has systematically examined whether such media bias exists beyond gender ratio imbalances in coverage that merely mirror societal-level structural and occupational gender inequalities. Using novel longitudinal data, we empirically isolate media-level factors and examine their effects on women’s coverage rates in hundreds of newspapers. We find that societal-level inequalities are the dominant determinants of continued gender differences in coverage. The media focuses nearly exclusively on the highest strata of occupational and social hierarchies, in which women’s representation has remained poor. We also find that women receive greater exposure in newspaper sections led by female editors, as well as in newspapers whose editorial boards have higher female representation. However, these differences appear to be mostly correlational, as women’s coverage rates do not noticeably improve when male editors are replaced by female editors in a given newspaper.

Finding effective ways to mitigate the effects of cognitive fatigue is important especially for high risk occupations. Previous work may have been affected by ceiling effects as it did not attempt to induce stress and fatigue prior to treatment. Therefore, establishing a method to induce stress and cognitive fatigue quickly and effectively in laboratory settings would be useful. Vigilance tasks are a validated method to induce perceived stress and task performance errors, but can be lengthy. We compared an abbreviated vigilance task at two vigil lengths (15-minute & 30-minute) against a 15-minute quiet break as a control, while measuring per-ceived stress, mood, anxiety, and objective performance on a cognitive task before and after each condition. Our results showed the vigilance tasks can induce stress and cognitive fatigue and show promise as a pre-study measure to reduce ceiling effects in stress and fatigue restoration studies.

Jane Speedy was leading the community of scholars in the “open space” session for March 2014 in Room 407. The Narrative Inquiry Centre held an “open space” session every month on the fourth floor of the Graduate School of Education. In “open space” sessions, one scholar led with exemplars of work that was troubling them/that they were troubling, after which others contributed their thoughts/comments and writing. Jane Speedy’s recent stroke had reduced/distilled/extended her writing into fragments. Her colleagues followed/responded with fragments of their own and thus this text was collaboratively written, in real time, on March 3, 2014.

Ceiling lifts have been implemented in skilled nursing facilities to reduce the physical demands associated with patient-handling activities. However, despite the apparent ergonomic advantages of using such interventions, multiple studies have reported the reluctance of health care professionals to use the provided ceiling lifts. This study investigated factors that affect the adoption of ceiling lift interventions and considered a process that involves individuals progressing through multiple stages of change that ultimately lead to an intervention’s use. Eighteen participants from three nursing homes, who have had opportunity to use ceiling lifts, completed a survey and were interviewed afterwards. Four physically demanding tasks where ceiling lifts would benefit the healthcare provider were examined with regard to their adoption stages and the factors that affect their use. The findings show that for obviously physically demanding tasks, most participants fully adopt the use of a ceiling lift. However, when using a ceiling lift leads to a decrease in work efficiency or could result in adverse effects, a participant’s tolerance of physical demands increases beyond recommended levels and results in the use of compromised lift methods.

In this paper, a room with four inlets located at the ceiling in the centre of the room with an exhaust installed at the bottom sidewall was modelled and investigated. The air is supplied through the individual room air inlets filtered by a high-efficiency particulate air filter, and the air is removed from the room via the exhaust located at the bottom sidewall. It leads to two possible inlet arrangements with four inlets: 1 × 4 array and 2 × 2 array. In the modelling, an obstacle is built to represent a workbench located underneath the inlets. Both the array designs are compared on their air flow and ability to remove gaseous contaminants. This study also suggests that the behaviour of the air jet impingement on the surface of the obstacle must also be considered in determining the design of the inlet array in a clean room. Practical application: This paper is intended to provide a practical guide to building service engineers on the design arrangement of inlets for a Class 7 clean room. By using the same concept, the design arrangement concept can be extended to the sizing of a workbench (i.e. the obstacle) when there is a fixed inlet design.

The present study investigates an optimum combination of absorptive and diffusing treatments for achieving preferred acoustics in classrooms. The measurements were carried out in a 1/10 scale model classroom, adding different amounts of absorptive and diffusing materials to one or more of five surfaces of the room. Adding diffusers on 25% of the ceiling area with the other 75% absorptive was more beneficial for achieving higher G50 and G values than adding absorptive materials on the entire ceiling. Adding absorptive materials on the entire ceiling area and diffusers on the front or side wall was beneficial for achieving shorter T30, EDT values and higher C50 values. Adding diffusers on the front or side wall slightly increased G50 and G values by more than 1 JND. Adding diffusers on the ceiling and lower front wall or side wall and adding diffusers on the ceiling a absorptive materials on the lower front wall were selected for consideration as the more successful treatments for classroom acoustic design.

The objective of this study is to examine the reduction in heating and cooling loads that may be attributed to the use of attic radiant barrier and to identify environmental parameters that influence this reduction. To this end, an experimental study was conducted in Zachary, Louisiana for 8 months on two houses built in the same manner and instrumented with thermocouples to measure the temperature in each hour and each layer of the roof. Results showed that an attic radiant barrier can reduce energy loads from 8% to 25% depending on the climatic conditions. Among the evaluated climatic parameters, ambient air temperature had the greatest effect on the ceiling heat flux.

Ceiling mounted personalized ventilation (PV) aims to provide clean outdoor air into human breathing zone without affecting indoor aesthetics in energy-efficient manner. In steady state, its performance depends much on the ceiling mounted air terminal device (ATD) because supply air momentum, other than human body thermal plume and ambient air flow, is the major driving force in the micro-environment of occupied zone. A typical office workplace consisting of ceiling mounted PV ATD and ambient air supply diffusers was simulated. One person was seated and another moving person was simulated by dynamic meshes in computational fluid dynamics (CFDs). A new index, computational personal exposure effectiveness (PEEc), was utilized to assess the performance of ceiling mounted PV system in regard to inhaled air quality under influence of moving person. Meanwhile, influence of evenly distributed ceiling mounted PV ATDs on inhaled air quality was also studied. According to numerical results, stability of ceiling mounted PV under dynamic environment with moving person was acceptable with minor changes of PEEc and inhaled air quality could be improved over larger occupied area for both seated person and moving person.

Many measurement biases affect student evaluations of instruction (SEIs). However, two have been relatively understudied: halo effects and ceiling/floor effects. This study examined these effects in two ways. To examine the halo effect, using a videotaped lecture, we manipulated specific teacher behaviors to be “good” or “bad” based on specific items on the evaluation form (the Teacher Behavior Checklist). To examine ceiling/floor effects, we expanded the standard 5-point rating to either 7 or 9 points. Across three universities, 537 students watched and rated the videotaped lecture. Both biases were robust and remained despite characteristics of the measure designed to combat them. Instead, direct instruction regarding how to use the evaluation forms seems to be necessary to limit these biases on ratings.

This article examines the state of African American Baptist women in ministry, historically and currently. Comparing views of women among the nine historically African American denominations, Baptists appear to be the most discriminatory. The author offers a historical overview with explanations of impediments to African American Baptist women's full inclusion in church leadership, Baptist or otherwise, and describes ways African American women have maneuvered around these obstacles to obey their callings. Drawing from available data from Baptist denominations, seminaries, and secondary literature, the article summarizes and assesses the current state of African American Baptist women in ministry with observations to interpret the data. Three “herstories”—histories of women—offer case studies of African American Baptist women in ministry to introduce some of the obstacles that African American Baptist women in ministry in general face in pursuing pastoral ministry. The article ends with suggestions for how affirmers of women in ministry and local churches can better support African American Baptist women in ministry. While there are more opportunities for African American Baptist women than ever before, there is still much farther to go. As Ella Baker used to say, “We who believe in freedom cannot rest until it comes.”

Tunnel blockage ratio is defined as the ratio of the cross-sectional area of the fire source to that of the tunnel. These fire sources in reality correspond to those that have considerable cross-sectional area such as trains or heavy goods vehicles, which are very common. The effect of tunnel blockage ratio on the maximum temperature under the ceiling in tunnel fires is analyzed using experimental data from three past studies. Results indicate that the maximum temperature decreases with the increase in the blockage ratio for small fires, while it does not vary with the blockage ratio for large fires. Previous models are modified based on above analysis by introducing a factor that accounts for the blockage effect. The modified models are more generally applicable.

There are situations where the data or the theory suggest or require, respectively, that one estimate the boundary lines that separate regions of observations from regions of no observations. Of particular interest are ceiling or floor lines. For example, many theories use terms such as veto player, constraint, only if, and so on, which suggest ceilings. Ceiling hypotheses have a nonstandard form claiming the probability of Y will be zero for all values of Y greater than the ceiling value of Yc for a given value of X. Conversely, ceiling hypotheses make no specific prediction about the value of Y for a given value of X except that it will be less than the ceiling value. Floors work by guaranteeing minimum levels. The article gives numerous examples of theories that imply ceiling or floor hypotheses and numerous examples of data that fit such hypotheses. The article proposes quantile regression as a means of estimating the boundaries of the no-data zone as well as criteria for evaluating the importance of the boundary variable. These techniques are illustrated for ceiling and floor hypotheses relating gross domestic product/capita and democracy.

The performance of a residential radiant chilled ceiling system combined with an outdoor air handling unit under steady operating conditions in summer was tested, and the stable operating characteristics of this system were analyzed. Indoor thermal environment parameters of room which employed this system were measured and analyzed and the thermal comfort evaluation of occupants was given. The results show that the composite system works well in summer, which can provide low- and high-temperature chilled water for the air supply terminal and the radiant terminal devices. Good thermal comfort can be achieved in room which employed this system, and no condensation risk occurs when it is applied in hot summer and cold winter zone of China. All the analysis provides a technical support for the popularization of the residential radiant chilled ceiling system combined with an outdoor air handling unit in China, and provides a reference for the further optimization of this system.

A simple correlation is theoretically presented and numerically studied for the temperature distribution of fire-induced flow along tunnel ceiling, which could correlate the flow temperature for various tunnel aspect ratios and fire intensities. The aspect ratio of the tunnel cross section in the numerical models varies from 0.5 to 2.0, and the heat release rate of the fire source varies from 4.4 to 22 MW. The numerical results indicate that the correlation could be utilized for all tunnels but with separate fitting constants for aspect ratios less than unity and greater than or equal to unity, including all fire intensities considered. This correlation could prove valuable in fire modeling and installation design of fire detectors in tunnel-shape buildings.