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2022 ◽  
Vol 12 (1) ◽  
pp. 474
Author(s):  
Mirela Cojocariu ◽  
Elena Liliana Chelariu ◽  
Ciprian Chiruţă

The negative effects of urbanization such as urban overheating, pollution, high population density and so on are being experienced by city inhabitants more than ever, thus motivating a high number of researchers to find viable solutions to mitigate these effects. The present paper aims to identify an assortment of ornamental plants appropriate to be successfully used in various facade covering systems for buildings located in Eastern European countries. For this purpose, throughout a vegetation season, the project’s team thoroughly monitored the percentage of survival, the coverage degree, and the behavior (biometric aspects and visual quality) of ten flowering species planted vertically and being oriented towards all four cardinal points. At the same time, the team conducted a thorough monitoring of some parameters of the soil (pH, humidity, and temperature) and of the outside environment (light intensity and temperature). Two experimental structures were built, insulated on the inside and covered at the top with thermal insulating panels, to simulate the same conditions of an insulated and unheated construction. The monitoring results showed that Heuchera x hybrida ‘Fire Alarm’, Heuchera x hybrida ‘Marmalade’ and Festuca galuca had a healthy appearance throughout the year, regardless of the cardinal orientation while providing a good coverage of the vertical surface.


2022 ◽  
Vol 961 (1) ◽  
pp. 012049
Author(s):  
Noor Sadiq ◽  
Miami M. Hilal ◽  
Mohammed Y. Fattah

Abstract Pavement is a complex structure consisting of several layers of different materials that influence its stressful behavior. Permanent deformation can occur in pavement layers of insufficient hardness at high temperatures. Significant rutting normally only occurs during hot weather, especially when the flexible pavement surface temperature is 60 ° C or higher. 2D model analysis using ABAQUS software can predict the rutting behavior. The modeling procedure assumes that all materials performance is a linear elastic. Surface, base, subbase and subgrade layers consist of models. Models in every pavement model, subgrade layers are supposed to have endless depth. This paper presents an element-finite model (FE) for the behavior analysis of the dynamic loading unreinforced and geogrid reinforced paving. Increased loading of the model and critical pavement responses for unreinforced or geogrid-reinforced flexible paving, such as vertical stress and vertical surface deflection, were determined. The results indicated a difference in the displacement results when adding the geogrid layer. The results also showed a significant improvement in the behavior of the pavement system. A parametric study was carried out on a type of Truck (3-S1) and the applied pressure was 36 tons with different thicknesses of the asphalt layer once 150 mm and again 25 cm at different temperatures of 20, 40 and 60 ° C. It was found that the higher the temperatures, the higher the displacement as well.


2021 ◽  
Author(s):  
P. Becak ◽  
T. Novak

The issue of the luminous flux radiation to the upper hemisphere is very broad and complex. The paper deals with the modelling of the vertical surface radiators. It presents an approach to unify the behaviour of these types of light sources. These will be understood as cosine radiators. If this cosine distribution curve is taken into account, then only the luminance and the light-active surface can be known to supplement the information about the radiation of such the light source. The luminance and radiated surface can be obtained relatively easily from real field measurements. The article presents the implementation of this data into lighting calculations and the creation of the distribution curves which are necessary for the radiation calculations of these surfaces. It also analyses the influence of the luminance and active areas on the radiated luminous flux and assign these values to the real radiators.


2021 ◽  
Vol 2119 (1) ◽  
pp. 012054
Author(s):  
A Sakhnov ◽  
O A Volodin ◽  
N I Pecherkin ◽  
A N Pavlenko

Abstract The paper presents numerical modelling of the liquid film spreading dynamics of the R21 (mol. fraction: 0.9) and R114 refrigerants mixture. We considered an outer flow along a round vertical cylinder at Reynolds number of 104 and various contact angles. The simulation was performed in OpenFOAM software on the basis of the volume of fluid (VOF) method. We have shown that the wetting front deforms at wetting angles of 30 and 50 degrees, and regular jets form. At the same time, it was demonstrated that at the wetting angle of 10 degrees the spreading front has practically a flat shape, but one may see some regular thickenings of the liquid film along the contact line of the front.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Timothy E. Higham ◽  
Mara N. S. Hofmann ◽  
Michelle Modert ◽  
Marc Thielen ◽  
Thomas Speck

AbstractArboreal habitats are characterized by a complex three-dimensional array of branches that vary in numerous characteristics, including incline, compliance, roughness, and diameter. Gaps must often be crossed, and this is frequently accomplished by leaping. Geckos bearing an adhesive system often jump in arboreal habitats, although few studies have examined their jumping biomechanics. We investigated the biomechanics of landing on smooth surfaces in crested geckos, Correlophus ciliatus, asking whether the incline of the landing platform alters impact forces and mid-air body movements. Using high-speed videography, we examined jumps from a horizontal take-off platform to horizontal, 45° and 90° landing platforms. Take-off velocity was greatest when geckos were jumping to a horizontal platform. Geckos did not modulate their body orientation in the air. Body curvature during landing, and landing duration, were greatest on the vertical platform. Together, these significantly reduced the impact force on the vertical platform. When landing on a smooth vertical surface, the geckos must engage the adhesive system to prevent slipping and falling. In contrast, landing on a horizontal surface requires no adhesion, but incurs high impact forces. Despite a lack of mid-air modulation, geckos appear robust to changing landing conditions.


2021 ◽  
Vol 117 (11/12) ◽  
Author(s):  
Michael C. Everett ◽  
Marina C. Elliott ◽  
David Gaynor ◽  
Austin C. Hill ◽  
Jesse Casana ◽  
...  

Mechanical loading of finger bones (phalanges) can induce angular curvature, which benefits arboreal primates by dissipating forces and economising the recruitment of muscles during climbing. The recent discovery of extremely curved phalanges in a hominin, Homo naledi, is puzzling, for it suggests life in an arboreal milieu, or, alternatively, habitual climbing on vertical rock surfaces. The importance of climbing rock walls is attested by several populations of baboons, one of which uses a 7-m vertical surface to enter and exit Dronkvlei Cave, De Hoop Nature Reserve, South Africa. This rock surface is an attractive model for estimating the probability of extreme mechanical loading on the phalanges of rock-climbing primates. Here we use three-dimensional photogrammetry to show that 82–91% of the climbable surface would generate high forces on the flexor tendon pulley system and severely load the phalanges of baboons and H. naledi. If such proportions are representative of vertical rock surfaces elsewhere, it may be sufficient to induce stress-mitigating curvature in the phalanges of primates.


2021 ◽  
Vol 930 ◽  
Author(s):  
Christopher J. Howland ◽  
Chong Shen Ng ◽  
Roberto Verzicco ◽  
Detlef Lohse

Many environmental flows arise due to natural convection at a vertical surface, from flows in buildings to dissolving ice faces at marine-terminating glaciers. We use three-dimensional direct numerical simulations of a vertical channel with differentially heated walls to investigate such convective, turbulent boundary layers. Through the implementation of a multiple-resolution technique, we are able to perform simulations at a wide range of Prandtl numbers ${Pr}$ . This allows us to distinguish the parameter dependences of the horizontal heat flux and the boundary layer widths in terms of the Rayleigh number $\mbox {{Ra}}$ and Prandtl number ${Pr}$ . For the considered parameter range $1\leq {Pr} \leq 100$ , $10^{6} \leq \mbox {{Ra}} \leq 10^{9}$ , we find the flow to be consistent with a ‘buoyancy-controlled’ regime where the heat flux is independent of the wall separation. For given ${Pr}$ , the heat flux is found to scale linearly with the friction velocity $V_\ast$ . Finally, we discuss the implications of our results for the parameterisation of heat and salt fluxes at vertical ice–ocean interfaces.


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