Three-Bay Square Hall with Asymmetrical Design

The structural design of the streamlined shape is the basis for high-speed train aerodynamic design. With use of the delayed detached-eddy simulation (DDES) method, the influence of four different structural types of the streamlined shape on aerodynamic performance and flow mechanism was investigated. These four designs were chosen elaborately, including a double-arch ellipsoid shape, a single-arch ellipsoid shape, a spindle shape with a front cowcatcher and a double-arch wide-flat shape. Two different running scenes, trains running in the open air or in crosswind conditions, were considered. Results reveal that when dealing with drag reduction of the whole train running in the open air, it needs to take into account how air resistance is distributed on both noses and then deal with them both rather than adjust only the head or the tail. An asymmetrical design is feasible with the head being a single-arch ellipsoid and the tail being a spindle with a front cowcatcher to achieve the minimum drag reduction. The single-arch ellipsoid design on both noses could aid in moderating the transverse amplitude of the side force on the tail resulting from the asymmetrical vortex structures in the flow field behind the tail. When crosswind is considered, the pressure distribution on the train surface becomes more disturbed, resulting in the increase of the side force and lift. The current study reveals that the double-arch wide-flat streamlined design helps to alleviate the side force and lift on both noses. The magnitude of side force on the head is 10 times as large as that on the tail while the lift on the head is slightly above that on the tail. Change of positions where flow separation takes place on the streamlined part is the main cause that leads to the opposite behaviors of pressure distribution on the head and on the tail. Under the influence of the ambient wind, flow separation occurs about distinct positions on the train surface and intricate vortices are generated at the leeward side, which add to the aerodynamic loads on the train in crosswind conditions. These results could help gain insight on choosing a most suitable streamlined shape under specific running conditions and acquiring a universal optimum nose shape as well.

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The Posterolateral Corner-Locked Technique Is Applicable in a Chinese Population Regarding the Tibial Component Rotation Alignment in Total Knee Arthroplasty

The Journal of Knee Surgery ◽

10.1055/s-0039-1678536 ◽

2019 ◽

Vol 33 (05) ◽

pp. 466-473

Author(s):

Chao-Hua Fang ◽

Cheng-Kung Cheng ◽

Tie-Bing Qu ◽

Jun-Hui Zhang ◽

Bo Zhang ◽

...

Keyword(s):

Total Knee Arthroplasty ◽

Knee Arthroplasty ◽

Tibial Component ◽

Chinese Population ◽

Posterolateral Corner ◽

Tibial Tubercle ◽

Tibial Osteotomy ◽

Tibial Tray ◽

Total Knee ◽

Asymmetrical Design

AbstractRotational malalignment between the femoral and tibial components in total knee arthroplasty (TKA) can affect clinical outcomes, but there is no consensus on how to best determine tibia tray orientation. The posterolateral corner-locked (PLCL) technique may be a new method. This study aims to assess the applicability of this technique in a Chinese population. Forty normal Chinese volunteers were recruited and underwent computed tomography (CT) of the lower limbs. Knee model reconstructions and simulated standard tibial osteotomy were conducted digitally. The transepicondylar axis (TEA), the Akagi line, and the line connecting the medial third of the tibial tubercle with the midpoint of the posterior cruciate ligament (PCL) were projected to the tibial cross-section and marked. The PLCL technique was applied using either symmetrical or asymmetrical tibial tray templates, and the anteroposterior (AP) axis of the tibial tray was marked. The angles between the TEA and these lines were calculated, and the statistical differences were analyzed. The angle between the TEA and the Akagi line and between the TEA and the line connecting the medial third of the tibial tubercle with the midpoint of the PCL were 96.90 ± 5.57 and 107.31 ± 5.95 degrees, respectively. The angles between the TEA and the AP axis of the symmetrical and the asymmetrical design tibial trays were 94.01 ± 4.21 and 96.65 ± 4.70 degrees, respectively. Except for the Akagi line and AP axis of the asymmetrical tibial tray, statistical differences were found between all lines (p < 0.05). The PLCL technique is principally suitable for Chinese patients requiring TKA when using the tibial component referred to in this study, although it may result in slight external rotation.

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Enhanced emission in organic nanocrystals via asymmetrical design of spirocyclic aromatic hydrocarbons

Nanoscale ◽

10.1039/d0nr01436b ◽

2020 ◽

Vol 12 (18) ◽

pp. 9964-9968

Author(s):

Yin-Xiang Li ◽

Xue-Mei Dong ◽

Meng-Na Yu ◽

Wei Liu ◽

Yi-Jie Nie ◽

...

Keyword(s):

Aromatic Hydrocarbons ◽

Organic Nanocrystals ◽

Asymmetrical Design

Due to the different structural symmtery of a spiro-center, distinguishing nanocrystal morphologies with unique crystallization-enhanced/quenched emission was achieved.

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Subtidal assemblages associated with a geotextile reef in south-east Queensland, Australia

Marine and Freshwater Research ◽

10.1071/mf04202 ◽

2005 ◽

Vol 56 (2) ◽

pp. 133 ◽

Cited By ~ 17

Author(s):

Rhys A. Edwards ◽

Stephen D. A. Smith

Keyword(s):

Fish Assemblages ◽

Benthic Communities ◽

Artificial Reef ◽

Demersal Fish ◽

Diverse Range ◽

Marine Habitats ◽

Sessile Invertebrates ◽

Hard Structures ◽

Asymmetrical Design ◽

Natural Reefs

In marine habitats, the use of geotextile materials as a ‘soft-engineering’ solution is increasingly being considered as an alternative to hard structures. However, very little is known about biological assemblages that develop on geotextile structures. This study provides the first ecological comparison of subtidal assemblages between Narrowneck Artificial Reef (NAR), a geotextile reef in south-east Queensland, Australia, and three nearby natural reefs. Benthic community structure, fish assemblages and habitat complexity were compared between reef types using an asymmetrical design. Although natural reefs supported distinct biotic assemblages, as a class, these reefs differed significantly from NAR. The artificial reef was dominated by macroalgae and supported fewer benthic categories, whereas the natural reefs were characterised by a diverse range of sessile invertebrates. Benthic and demersal fish assemblages were less diverse on NAR, but pelagic fish assemblages were similar on both reef types. The substratum of NAR was less complex than that of the natural reefs; this physical variable was correlated with some of the differences in benthic communities and benthic and demersal fish assemblages. It is likely that the key determinants of the biotic patterns observed in this study are interactions between the age of NAR and the physical properties of geotextile substratum.

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Effect of the Finite Source Material on Electromigration Performance of a Novel Interconnect Test Structure

MRS Proceedings ◽

10.1557/proc-428-87 ◽

1996 ◽

Vol 428 ◽

Author(s):

Nguyen D. Bui

Keyword(s):

Strong Dependence ◽

Source Material ◽

Failure Model ◽

Finite Source ◽

Design Structure ◽

Symmetrical Design ◽

The Difference ◽

Interconnect Systems ◽

Asymmetrical Design ◽

Asymmetric Contact

AbstractEffects of finite source material, in multilevel interconnect systems, on reliability has been investigated. Two types of novel test structures were used in this study: 1] asymmetrical design structure in width and thickness for the top and bottom conductor layers, 2] symmetrical design structure in width and thickness for the top and bottom conductor layers. The results of the asymmetric contact and via chains studies showed that the electromigration lifetimes were not effected by the difference in the magnitude of the finite source material. The electromigration lifetimes of the symmetrical via structure, in width and thickness for the top and bottom conductor layers, exhibited a strong dependence on the finite source material. A failure model is proposed to explain the effect of finite source material on electromigration performance in such interconnect systems.

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Mathematical modeling of thermal processes during "cassette" crystallization of chalcogenides

Modern Electronic Materials ◽

10.3897/j.moem.6.1.55282 ◽

2020 ◽

Vol 6 (1) ◽

pp. 9-16

Author(s):

Anatoly I. Prostomolotov ◽

Nataliya A. Verezub

Keyword(s):

Heat Exchange ◽

Mathematical Models ◽

Crystallization Front ◽

Reduction Rate ◽

Exchange Model ◽

Radiative Heat Exchange ◽

Thermal Processes ◽

Melt Crystallization ◽

Heating Unit ◽

Asymmetrical Design

A new, relatively simple and highly efficient modification of the directional melt crystallization method in the form of a multi-cassette process has been considered. This study is based on Russian Patents and technological studies conducted at National Research and Technological University MISiS. As a result, mathematical models of a multi-cassette method have been developed for 3D radiation and conduction analysis of thermal processes in the entire volume of the heating unit and 2D analysis of convection and conduction heat exchange in a separate cassette. Parameters have been calculated on the basis of these mathematical models for clarifying the effect of heating unit component arrangement and dimensions on the formation of thermal fields in cassette units, the effect of vertical homogeneity of heat supply to the cassette unit and heating power reduction rate during crystallization on the shape of the crystallization front, as well as the effect of small asymmetry in cassette design and violation of cassette bottom cooling homogeneity on convection and asymmetrical heat transfer. Application of the conductive and radiative heat exchange model to the entire heating unit has allowed us to calculate process parameters on the basis of which we have analyzed the effect of heating unit components, their arrangement and temperature on the heat exchange conditions at the cassette unit boundaries. Application of the convective and conductive model to one growth cassette has shown that asymmetrical design and boundary thermal conditions as well as unstable vertical temperature gradient lead to the formation of convection vortices and substantial crystallization front deviation from planar shape. Calculations on the basis of the convective mass exchange model have shown that an increase in the crystallization rate by one order of magnitude greatly increases the tellurium flow into the crystal thus substantially altering the melt composition in the vicinity of the crystallization front and hence serving as a potential origin of dendrite growth. The authenticity of the calculation results has been verified in a number of tests aimed at analyzing the effect of heat and mass transport on crystallization front shape for cassette cooling rates that are typical of polycrystalline bismuth telluride growth processes.

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Physics of animal health: on the mechano-biology of hoof growth and form

Journal of The Royal Society Interface ◽

10.1098/rsif.2019.0214 ◽

2019 ◽

Vol 16 (155) ◽

pp. 20190214

Author(s):

Ramzi Al-Agele ◽

Emily Paul ◽

Sophie Taylor ◽

Charlotte Watson ◽

Craig Sturrock ◽

...

Keyword(s):

Growth Rate ◽

Weight Bearing ◽

Animal Health ◽

Interdisciplinary Approach ◽

Growth Stress ◽

Ability To Work ◽

Multi Scale ◽

Order Of Magnitude ◽

Asymmetrical Design ◽

Working Equids

Global inequalities in economic access and agriculture productivity imply that a large number of developing countries rely on working equids for transport/agriculture/mining. Therefore, the understanding of hoof conditions/shape variations affecting equids' ability to work is still a persistent concern. To bridge this gap, using a multi-scale interdisciplinary approach, we provide a bio-physical model predicting the shape of equids’ hooves as a function of physical and biological parameters. In particular, we show (i) where the hoof growth stress originates from, (ii) why the hoof growth rate is one order of magnitude higher than the proliferation rate of epithelial cells and (iii) how the soft-to-hard transformation of the epithelium is possible allowing the hoof to fulfil its function as a weight-bearing element. Finally (iv), we demonstrate that the reason for hoof misshaping is linked to the asymmetrical design of equids' feet (shorter quarters/long toe) together with the inability of the biological growth stress to compensate for such an asymmetry. Consequently, the hoof can adopt a dorsal curvature and become ‘dished’ overtime, which is a function of the animal's mass and the hoof growth rate. This approach allows us to discuss the potential occurrence of this multifaceted pathology in equids.

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