Vertical Surfaces Research Articles

Subambient daytime radiative cooling of vertical surfaces.

Subambient daytime radiative cooling enables temperatures to passively reach below ambient temperature, even under direct sunlight, by emitting thermal radiation toward outer space. This technology holds promise for numerous exciting applications. However, previous demonstrations of subambient daytime radiative cooling require surfaces that directly face the sky, and these cannot be applied to vertical surfaces that are ubiquitous in real-world scenarios such as buildings and vehicles. Here, we demonstrate subambient daytime radiative cooling of vertical surfaces under peak sunlight using a hierarchically designed, angularly asymmetric, spectrally selective thermal emitter. Under peak sunlight of about 920 watts per square meter, our emitter reaches a temperature that is about 2.5°C below ambient temperature, corresponding to a temperature reduction of about 4.3° and 8.9°C compared with a silica-polymer hybrid radiative cooler and commercial white paint, respectively.

The impact of nanomaterials on energy-centric form-finding of educational buildings in semi-arid climate

In the modern world, the use of novel technologies in architecture has become highly significant and transformative for human-environment interactions. One of the most critical concerns in architecture is achieving optimal forms and selecting suitable materials for effective design across diverse climatic zones. Also, adopting innovative climate design methods in public spaces, such as educational buildings, is essential due to their strategic urban locations and diverse user populations. Therefore, the research conducted in this study focuses on two main aspects: optimizing building form based on energy consumption and solar radiation received by vertical surfaces, and, selecting appropriate nanomaterials for building surface to reduce energy usage and maintenance costs. This study begins with theoretical foundations, defining the key terms through a comprehensive review of relevant literature. Then, four identical classroom modules with consistent height and floor levels are proposed, and Energy Plus software is used to evaluate the energy consumption based on a module simulation in initial forms of square and rectangle with varying proportions. The best module and orientation is determined using specified climatic data of the coldest and the hottest days of the year. Further, investigations involve combining these modules in various layouts, emphasizing those that align with the functional requirements of educational spaces. Finally, two parameters of energy consumption and solar radiation on vertical surfaces are measured during specified time interval between sunrise and sunset. The results indicate that among the four proposed modules, the 18 × 18 module with a north-south orientation is the most optimal in the semi-arid climate of Tehran, and therefore, Type 3 layout demonstrates the best performance for energy consumption. This is while by incorporating selected nanotechnology (self-cleaning nanomaterial paint), energy usage decreases in all layouts, regardless of the season.

Craspedia blepharia (Compositae/Asteraceae, Gnaphalieae), a new species from Garibaldi Ridge in Nelson/Tasman, South Island of New Zealand

ABSTRACT Craspedia G.Forst., a genus of tribe Gnaphalieae (Compositae/Asteraceae), is confined to Australia and New Zealand. Twelve species, including Craspedia blepharia Breitw. & Courtney, which we are describing here, are now recognised in New Zealand. Craspedia blepharia is known only from Garibaldi Ridge in Nelson/Tasman, South Island of New Zealand. It is a strong calcicole, confined to exposed, vertical surfaces of limestone cliffs and dolines and quartzose sandstone cliffs which receive calcium-rich seep-water. Its rosettes grow either individually or in dense clumps on cliff faces, thus allowing the plants to receive water from surface water flow. It is distinguished from other New Zealand Craspedia by its rosette leaves clad with a hispid adaxially very dense and abaxially sparse indumentum of very long (2.2–3 mm), usually curved, uniseriate, multiseptate, usually slightly brown or colourless, translucent trichomes that may have a very thin curly, flagellate tip, and leaf margins with a thin white rim formed by the flagellate tips of these long, curved trichomes. We are providing the formal taxonomic treatment together with illustrations and descriptions of its morphology, distribution, habitat, ecology, phenology, and etymology, as well as an assessment of its conservation status.

Green horizons: Exploring the potential of vertical green walls

The term “Green walls” also known as vertical gardens or living walls has emerged as a promising solution to combat the environmental challenges posed by rapid urbanization. This review explores the concept ornamental, plant choice suitable and benefits associated with green walls in urban settings. Utilising vegetation to cover vertical surfaces, green walls offer several benefits to the environment, society and economy. They contribute to improved air quality, noise reduction, energy conservation and biodiversity enhancement. Vertical greenery allows for the utilization of unused wall surfaces, creating green areas without occupying valuable ground space, which is often scarce in urban environments. Additionally, green walls offer aesthetic appeal, promote urban agriculture and create opportunities for community engagement. However, their implementation requires careful consideration of factors such as structural integrity, irrigation and maintenance. Despite these challenges, green walls offer a sustainable and innovative approach to enhancing the quality of urban life while mitigating the negative impacts of urban development on the environment. The current emphasis highlights the significance of green walls as an effective tool in sustainable urban planning, underscoring the need for further research and their integration into urban planning practices.

Combined fluid and ferrofluid buoyancy force, heat absorption and non linear ferro-viscosity effects on ferro- hydrodynamics fluid flow in orthogonal porous surface

Mixed convection incompressible ferro-hydrodynamic (FHD) boundary layer fluid flow on vertical porous curvilinear orthogonal surfaces is examined in our present study in presence of combined fluid and ferro-fluid buoyancy force, nonlinear ferro-viscosity parameter, and heat absorption/generation effects. Design/Methodology/Approach: Types of Prandtl momentum and thermal boundary layer partial differential equations in a curvilinear system are converted into non-dimensional ordinary nonlinear differential equations (ODE) by introducing dimensionless velocities, temperature functions and similarity variable. Missing initial conditions are found by shooting method and solving the system of nonlinear ODEs by Runge-Kutta integration scheme of order six. With the help of MATLAB, the numerical solutions are graphically displayed in the forms of primary velocity profile, secondary velocity profile, and temperature profile. Three types of magnetic nano-ferrofluid are considered such as water-based ferrofluid (Taiho W-40), Hydrocarbon based ferrofluid (EMG-901) and kerosene-based ferrofluid (C1-20B) whose Prandtl numbers are 44.3, 79.3 and 128 respectively shown in Table 1. For kerosene based ferro-fluid, Table 3 presents the coefficient of skin friction and heat flux. Finding: The effects of combined fluid and ferrofluid buoyancy forces, nonlinear ferro-viscosity parameter, suction/injection, and heat absorption/generation parameters on the velocity and temperature profiles are investigated. Our physical interest is to calculate the local shearing stresses and the local heat flux at the surface. Finally, we have made comparisons of the results which are highlighted the validity of our numerical calculations adopted for the presence study.

Understanding the influence of impedance transitions of acoustically reflective vertical surfaces on the frequency-dependent effectiveness of absorptive ceilings in large non-Sabinian empty spaces

An unexpected phenomenon was observed during measurements of reverberation time in empty spaces to be fitted out, in which the only sound absorbing treatment consists of mineral fiber tiles on the ceiling, a material typically highly absorbing at mid and high frequencies during laboratory measurements: this involves a systematic increase of the reverberation time in octave bands between 1 kHz and 4 kHz in the measured empty spaces. The physical understanding of this surprising observation has focused on the question of the influence of impedance transition on sound scattering, and the influence of the frequency-dependent scattering properties of acoustically reflective vertical surfaces of different natures (glazing, plasterboard lining, masonry) of these empty spaces on the efficiency of a sound absorbing ceiling. These scattering phenomena were studied and modeled in a computer model in order to verify the model's adjustment hypothesis, an essential initial step before the study of the acoustic parameters in future fitted spaces and the effectiveness of acoustic solutions for space planning of open plane offices. Good consistency between the measurements and the empty model was observed when the frequency-dependent scattering behaviour of the vertical reflecting surfaces of different nature was taken into account in the simulation.

Effectiveness of intensive motor learning approaches from working on a vertical surface on hemiplegic children’s upper limb motor skills, a randomized controlled trial

Purpose This study compares the effect of intensive motor learning approaches on improving the quality of upper extremity skills in children with unilateral cerebral palsy (UCP) by working on vertical surfaces versus horizontal surfaces during rehabilitation sessions. Materials and methods Forty UCP children of both sexes were randomized into two equal groups. All participants received 60 min of intensive motor learning approaches three days/week for three successive months. These approaches included constraint-induced movement therapy (CIMT), in which children wore a splint or sling on the unaffected upper limb, as well as hand-arm bimanual intensive training (HABIT) that requires the use of both hands during specific play-based activities. The control group received training on a horizontal surface while the child sat in front of an elbow-height table while the study group (vertical surface training) sat or stood in front of a wall/mirror/board. The task requirements were graded to ensure success. Results Statistically significant differences were detected between the mean values of post-treatment of all scorers, with a greater percentage of improvement in favor of the study group. Conclusions This study revealed that working on a vertical surface improved upper limb motor skills more significantly than working on a horizontal surface.

On the non-linearity of rheological film condensation

Condensation of non-Newtonian fluids is a less explored research field but has tremendous potential in the industry. We propose a mathematical theory to model the behaviour of non-Newtonian film condensation on vertical surfaces. The simple theory can contribute to understanding the operation of many engineering appliances using motor oils, polymeric liquids, and fuels. The well-known power-law model approximates the viscosity of condensate. We vary the power-law index (n) within 0.8≤n≤1.2 to encompass the behaviour of shear-thinning, Newtonian and shear-thickening films, while the flow consistency index (μ0) remains constant throughout the study. Since the film flow is gravity-driven, stream-wise advection is expected to dominate over cross-stream advection. We, however, establish the subtle role of cross-stream advection within the thin condensate film. We have identified a thinner film, a lower condensate drainage rate and a greater average heat transfer coefficient (hm) as an influence of the cross-stream advection. An exclusion of cross-stream advection transforms temperature distribution across the film from non-linear to linear. The linear temperature distribution is unrealistic for Ja≥0.5. We illustrate approximately 5% error incurred for neglecting cross-stream advection in estimating hm at Ja=0.81 and n=0.8. The error increases with a further decrease in n values or an increase in the Ja. The exclusion of cross-stream advection affects the film-thickness and average heat transfer disproportionately in shear-thinning and shear-thickening regimes. Finally, we propose mathematical expressions to estimate heat transfer coefficient and Nusselt number, which would be helpful for field engineers.

Fuzzy adaptive impedance control for the two-layered vertical cable-driven parallel robot

This study unveils a novel two-layered vertical octahedron cable-driven parallel robot (TLVO CDPR), distinctively engineered for effective force interactions with vertical surfaces while preventing collision with cables. It pioneers an innovative control strategy integrating a position-based fuzzy adaptive impedance controller with a fuzzy Proportional – Integral – Derivative (PID) controller, adeptly managing both the pose and contact force of the robot. While dual control application is often found in rigid-link robots, it remains a largely unexplored frontier in the realm of CDPRs, despite its critical importance in sectors like manufacturing and assembly. The fuzzy adaptive mechanism significantly boosts impedance control efficacy in the face of unpredictable, non-uniform working surfaces, ensuring algorithmic stability and convergence. Concurrently, fuzzy logic is harnessed to optimize PID controller performance. The forward kinematics challenge is efficiently tackled using a least squares method coupled with an Inertial Measurement Unit (IMU), ensuring swift and precise solutions. The robustness and adaptability of the robot and its control systems are thoroughly validated through extensive experimental trials, involving diverse trajectories and varying uncertainties on vertical working surfaces.

Measuring the real radon exhalation from walls in buildings

Building materials may significantly contribute to indoor radon activity concentration. Measuring the radon exhalation rate directly on the existing building elements represents the most accurate and reliable method to assess the building materials’ contribution. However, due to the method’s inner difficulties, no specific apparatus has been developed and documented in the literature.An innovative apparatus has been designed, constructed, and commissioned to measure the radon exhalation rate in situ from vertical surfaces of existing building walls. The apparatus is non-destructive, completely self-standing, and easily transportable. The sealing mechanism has been demonstrated to assure airtightness similarly to destructive setups. The measurements’ repeatability is less than 10% at different radon exhalation rates.The apparatus introduced is the only available solution to measure the site-dependent contribution of building materials to the indoor radon concentration. The apparatus allows for improving the specificity, so the effectiveness, of the remedial interventions to reduce the radon-related health risk.

Epoxy resin-based polymer-wall stabilized liquid crystal films with low driving voltages and improved mechanical performance for smart window applications

Polymer stabilized liquid crystals (PSLCs) have wide applications in smart windows and light shutters. However, for most applications, it requires low driving voltages and high mechanical performance, which is arduous to achieve both. Herein, a novel epoxy resin-based PSLC device is prepared showing improved electro-optical and mechanical properties simultaneously. This is benefited from the construction of a period polymer wall structure in liquid crystal matrix through cationic polymerization of epoxy monomers and preparation of multi-functional surfaces through self-assembly of silane mixtures. The multi-functional surfaces could ensure homeotropic alignment of liquid crystals and photo-polymerize with the polymer networks. As a result, the polymer-wall stabilized liqduid crystal (PWSLC) film with multi-functional surfaces shows lower (24%) saturation voltage, higher (20%) contrast ratio and improved (2.4 times) peel strength than the PSLC film with only vertical alignment surfaces. This research provides important reference to experiment and manufacture of reverse-mode dimming films for smart windows applications.

Large-scale prediction of solar irradiation, shading impacts, and energy generation on building Façade through urban morphological indicators: A machine learning approach

Incorporating Building-integrated Photovoltaics (BIPVs) into urban environments offers a sustainable approach by transforming building exteriors into renewable energy sources, especially by utilizing the extensive vertical surfaces in cities. While individual building applications have been extensively studied, there is a lack of research on BIPV potential at the urban scale due to the complexity of urban fabrics. Therefore, this study presents a novel method for predicting large-scale solar irradiation and energy generation on building surfaces using urban morphological indicators through machine learning models. Using an Australian city as a case study, a hierarchical two-level machine learning model is developed to predict the solar potential for building façade PV systems. The model incorporates 13 urban morphological predictors to determine average shading height and unshaded solar irradiance. By combining these predictions with wall datasets and different façade BIPV efficiencies, the proposed method predicts unshaded electricity generation. The results showcase high efficiency and accuracy in the prediction of the shading height, solar irradiance, and electricity generation. This innovative approach aids urban planners in considering large-scale surface BIPVs into urban development.

Patient´s perception of spatial complexity in emergency spaces of a hospital in China: a method for stakeholders to improve design and management

ABSTRACT The focus of medical facility users has shifted from prioritizing epidemic prevention to prioritizing experience after COVID-19, particularly in the emergency department (ED) of a large-scale Chinese hospital. The current visual elements of the emergency department provide a negative perception to the patients who visit the department. The study aims to optimize the ED's spatial design by understanding how visual elements affect patients' perception of spatial complexity. The methodology involved recreating a patient's typical path through the ED using data from the hospital information system (HIS), capturing images at 70 location nodes, and calculating the fractal dimensions of these images using the box-counting method. Visual elements were categorized into eight groups, and their fractal dimensions and proportions within the images were analyzed. A breakpoint graph was developed to track changes in spatial complexity perception as patients move through the ED. Statistical analysis, including correlation and one-way ANOVA, revealed that spatial attributes and lighting conditions significantly impact spatial complexity. From the results, grouping analysis was conducted on the visual elements of the horizontal surfaces, vertical surfaces, ceiling, furniture, and vegetation. Further optimization was proposed. In conclusion, this study highlights the importance of visual elements in emergency spaces, directly influencing users' perception of spatial complexity. The relationship between spatial complexity and fractal dimension is further emphasized. Stakeholders and designers can use the findings of this study as references to make informed decisions to improve the user's experience in the healthcare-built environment.

Effects of thermomechanical parameters on surface texture in filament materials extrusion: outlook and trends

The material extrusion process has been widely used to manufacture custom products. However, the surface texture varies due to the additive mechanism of the process, which depends on the layer height and surface orientation, resulting in varying average surface roughness values for inclined, flat and vertical surfaces. Different strand welding conditions result in non-uniform internal stresses, surface distortions, layer traces, weak bonding, non-uniform pores and material overflow. This paper comprehensively examines material extrusion process achievements in surface texture quality and studies and summarises the most influential processing parameters. Parameter effects are critically discussed for each topic; flat, inclined, and vertical surfaces. The results of this research help reduce post-processing.

Numerical analysis of magnetohydrodynamic mixed convection and entropy generation in a curvelinear lid-driven cavity with carbon nanotubes and an adiabatic cylinder

Mixed convection convection is a vital subject and it is beneficial in many engineering applications. The current paper addresses this subject with a novel geometry and very vital variables including magnetohydrodynamic influences on the forced/free convection as well as the reproduction of irreversibilities in an enclosure filled with water/carbon nanotubes (CNT) and a nonadiabatic cylinder. The top wall is split from the middle and moves in different directions to drive the isotherms which are generated from the bottom wall and cold from the vertical surfaces. The numerical analysis was carried out using finite element method; the variables are Reynolds number (40–200), Richardson number (0.01–10), Hartmann number (0–62), inclined magnetohydrodynamic angle (0–60), volume concentration (0–0.08) while Prandtl number has kept constant at 6.2. The results show that the transformation of heat, as well as the fluid flow, are largely influenced by the change of variables, where increasing Reynolds number, Richardson number enhances heat and increases the flow circulation. Furthermore, heat transfer enhances by 57 % when increasing Ri from 0.1 to 10 at Re=41 and this enhancement increases to 62.5 % at Re = 200. Furthermore, increasing the concentration of the carbon nanotube can cause heat transfer but decrease the circulation of the fluid. In contrast, the transfer of heat as well as the flow streams are remarkably decreased with the increase of the Hartmann at zero inclination angle; however, the value of the Nusselt average increases with the increase of the inclination angle. Moreover, the value of Nusselt average decreses by 34.7 % when increasing Ha from 0 to 62 at Re = 200. Furthermore, the total entropy generation increases as Richardson number, Reynolds number, and volume concentration increase; in contrast, detraction with the rise of the MHD.

Estimation of total solar irradiance on vertical surfaces for all-sky conditions adaptive to coastland surfaces

This paper presents an algorithm for estimating three components of total solar irradiance on vertical surfaces in coastlands, including direct, sky diffuse and ground reflection irradiance. The algorithm aims to cover changeable weather and ground surfaces in coastlands. For this purpose, Sanya located on Hainan Island of China has been selected as a representative city. Initially, a dataset of horizontal irradiance measured from 2005 to 2014 has been used to statistically analyze the frequency distribution of sky conditions, resulting in a classification of coastal weather into 4 categories. Afterward, using the vertical irradiance data collected by a novel measurement system, the performance of 15 sky diffuse irradiance models has been compared under coastal weather types. As a result, an algorithm for vertical sky diffuse irradiance adapted to all-sky conditions (Alg-s) is developed. Concurrently, regression models of reflection irradiance from sea and beach on vertical surfaces (Mr) are established using correlation analysis and the least squares method. Combining the above two sub-models, an all-sky conditions total solar irradiance model on vertical surfaces in coastlands is developed. Compared to previous studies, the new model improves the prediction accuracy of total vertical irradiance, with RRMSE and MAPE reduced by 14.2 % and 10.6 % respectively.

New Acoustic Design for the Piscina Mirabilis Located nearby the Port of Misenum

Many heritage buildings from ancient Rome are being refurbished based on their original plan’s structure. One of them is the piscina mirabilis located nearby in Naples, which was a cistern used by the Romans to collect drinkable water for the navy waiting in the port of Misenum. The piscina mirabilis has similar architectural characteristics to a “cathedral”; however, its current precarious architectural state is the result of high levels of humidity that have caused the proliferation of mold on its vertical and horizontal surfaces over the centuries. Acoustic measurements were conducted inside the piscina mirabilis, highlighting an existing condition of the room being very reverberant, not suitable for occasional speech and conversations. The design proposed by the authors involves some mitigation solutions for the acoustics, mainly focused on controlling the low–medium frequencies and the realization of a restoration project consisting of a raised timber-floored walkway that runs along the perimeter walls, with the addition of water covering the existing floor as a natural element dominating the room volume, which represents the primary function of the building in antiquity. A waterfall was designed to be on the northern side wall. Acoustic studies were an important part of the refurbishment strategy, and a mitigation solution was devised to control medium–low frequencies by using inflated balloons of different sizes that were suspended from the ceiling vaults instead of widely used acoustic panels. The proposed strategy lowered the reverberation time by 3–4 s to accommodate a minimal level of conversational understanding. Such a solution is appropriate for this heritage building as well as other future conservation projects.

A novel hybrid adhesion method and autonomous locomotion mechanism for wall-climbing robots

In this paper we propose a novel adhesion method for the tracked wall-climbing robot. The method is based on the use of the tape, which the robot affixes to the wall during its movement. The adhesive side of the tape adheres to the wall, while the non-adhesive side allows for the robot's movement. The robot attaches to the tape using spikes located on the surface of its tracks. We developed the experimental prototype with a tracked locomotion mechanism weighing 1.2 kg, measuring 212 mm × 294 mm × 131 mm, and capable of carrying a payload of 2 kg. The battery life of the prototype is 3.5 h in standby mode and 1.8 h in moving mode. The prototype is controlled remotely through video transmission in manual mode and can move on both vertical and horizontal surfaces, and transition between them. The prototype has demonstrated the ability to move along a vertical surface, transition from a horizontal to a vertical surface, and recover from an unstable position in the case of a capsize. We used basic components and 3D printing in the manufacturing process. This suggests that we can make the prototype better by using different materials and components.

Experimental study on the characteristics of frost formation and defrosting water retention between vertical double surfaces with different wettability

Frost formation and defrosting water retention directly affect the heat transfer process of outdoor finned tube heat exchanger, which in turn influences the energy efficiency of air source heat pumps for building heating. Three typical wettability surfaces were prepared, including a bare copper hydrophilic surface (BCS), a hydrophobic copper surface (HCS) and a superhydrophobic copper surface (SHCS). The above three surfaces are combined in pairs to construct three different wettability combinations, which are Combination 1: HCS-BCS, Combination 2: BCS-SHCS and Combination 3: HCS-SHCS, respectively. Frosting-defrosting experiments between vertical double surfaces are carried out on the above combinations. The results illustrated that the combinations with SHCS exhibit excellent frost inhibition properties. Compared with Combination 1, the channel filling rate of Combination 2 and Combination 3 were reduced by 16.79 % and 30.09 % respectively at a frosting time of 60 min. The defrosting time of the combination is determined by the slower defrosting of the two surfaces. Compared with Combination 2, the defrosting rate of Combination 3 is improved by up to about 12.93 %. Avoiding the formation of large-sized liquid films and droplets or utilizing the “absorption” phenomenon caused by wettability differences between surfaces are important measures to reduce the possibility of bridge formation during the defrosting process. And the greater the wettability difference, the more obvious the “absorption” phenomenon became. Spherical droplets on the SHCS can be completely absorbed by the liquid film on BCS under the action of differential surface tension. Neither Combination 2 nor Combination 3 formed a liquid bridge at a surface spacing of 2 mm. The research will provide theoretical support for the selection of fin spacing and fin coating type under different working conditions in practical engineering.

Transgenic Drosophila melanogaster Carrying a Human Full-Length DISC1 Construct (UAS-hflDISC1) Showing Effects on Social Interaction Networks.

Disrupted in Schizophrenia 1 (DISC1) is a scaffold protein implicated in major mental illnesses including schizophrenia, with a significant negative impact on social life. To investigate if DISC1 affects social interactions in Drosophila melanogaster, we created transgenic flies with second or third chromosome insertions of the human full-length DISC1 (hflDISC1) gene fused to a UAS promotor (UAS-hflDISC1). Initial characterization of the insertion lines showed unexpected endogenous expression of the DISC1 protein that led to various behavioral and neurochemical phenotypes. Social interaction network (SIN) analysis showed altered social dynamics and organizational structures. This was in agreement with the altered levels of the locomotor activity of individual flies monitored for 24 h. Together with a decreased ability to climb vertical surfaces, the observed phenotypes indicate altered motor functions that could be due to a change in the function of the motor neurons and/or central brain. The changes in social behavior and motor function suggest that the inserted hflDISC1 gene influences nervous system functioning that parallels symptoms of DISC1-related mental diseases in humans. Furthermore, neurochemical analyses of transgenic lines revealed increased levels of hydrogen peroxide and decreased levels of glutathione, indicating an impact of DISC1 on the dynamics of redox regulation, similar to that reported in transgenic mammals. Future studies are needed to address the localization of DISC1 expression and to address how the redox parameter changes correlate with the observed behavioral changes.