scholarly journals Exploring the world of micro sculptures - subfossil Cladocera remains under the SEM

2016 ◽  
Vol 7 (2) ◽  
Author(s):  
Izabela Zawiska ◽  
Edyta Zawisza ◽  
Marta Wojewódka ◽  
Artem Y. Sinev
Keyword(s):  
Three Dimensional ◽  
Body Parts ◽  
Microstructural Characteristics ◽  
Present Contribution ◽  
Sem Images ◽  
Subfossil Cladocera ◽  
Cladocera Remains ◽  
Cladoceran Species ◽  
Living Species ◽  
Species Specific

<p>The scanning electron microscope (SEM) is widely used for the identification of microstructural characteristics and morphology of different microorganisms. Common procedures are based and developed for remains of living species. This paper presents an effective method for drying and preparing subfossil Cladocera remains for SEM observation, which has been recently adapted and tested on several samples originating from different American and European lakes. This method results to be fast and cheap, as it excludes the use of expensive and toxic reagents. Moreover, it allows to recognize the micro sculpture and other species specific characteristics present on the different body parts of the Cladocera remains. The present contribution provides 29 high quality pictures of 12 cladoceran species at magnification between 200x and 11,000x. SEM images reveal  that the patterns observed on the shells under the light microscope actually are always three dimensional structures.</p>

Development and Validation of a Three-Dimensional Multiphase Flow CFD Analysis for Journal Bearings in Steam and Heavy Duty Gas Turbines

2012 ◽  
Author(s):  
Stephan Uhkoetter ◽  
Stefan aus der Wiesche ◽  
Michael Kursch ◽  
Christian Beck
Keyword(s):  
Experimental Data ◽  
Multiphase Flow ◽  
Gas Turbines ◽  
High Speed ◽  
Three Dimensional ◽  
Air Entrainment ◽  
Journal Bearings ◽  
Heavy Duty ◽  
Present Contribution ◽  
Two Phase

The traditional method for hydrodynamic journal bearing analysis usually applies the lubrication theory based on the Reynolds equation and suitable empirical modifications to cover turbulence, heat transfer, and cavitation. In cases of complex bearing geometries for steam and heavy-duty gas turbines this approach has its obvious restrictions in regard to detail flow recirculation, mixing, mass balance, and filling level phenomena. These limitations could be circumvented by applying a computational fluid dynamics (CFD) approach resting closer to the fundamental physical laws. The present contribution reports about the state of the art of such a fully three-dimensional multiphase-flow CFD approach including cavitation and air entrainment for high-speed turbo-machinery journal bearings. It has been developed and validated using experimental data. Due to the high ambient shear rates in bearings, the multiphase-flow model for journal bearings requires substantial modifications in comparison to common two-phase flow simulations. Based on experimental data, it is found, that particular cavitation phenomena are essential for the understanding of steam and heavy-duty type gas turbine journal bearings.

Enhanced Performance of Ultrafiltration Membrane with Powdered Zeolite Addition for Secondary Effluent Treatment

2013 ◽  
Vol 838-841 ◽  
pp. 2712-2716
Author(s):  
Yong Tu ◽  
Yong Gang Bai ◽  
Yong Chen ◽  
Wei Jing Liu ◽  
Jun Xu ◽  
...  
Keyword(s):  
Membrane Fouling ◽  
Fluorescence Spectra ◽  
Municipal Wastewater ◽  
Three Dimensional ◽  
Treatment Plant ◽  
Ultrafiltration Membrane ◽  
Effluent Treatment ◽  
Secondary Effluent ◽  
Municipal Wastewater Treatment ◽  
Sem Images

The research on ultrafiltration membrane assisted by powdered zeolite for the treatment of secondary effluent from a municipal wastewater treatment plant was studied. The results show that membrane fouling rate is reduced by pre-coating the ultrafiltration membrane with powdered zeolite, and the treatment performance of secondary effluent is enhanced. UV-vis, three-dimensional excitation emission matrix (3D-EEM) fluorescence spectra and scanning electron microscopy (SEM) images for ultrafiltration were also discussed.

Aerothermal Investigation of a Rib-Roughened Trailing Edge Channel With Crossing-Jets—Part I: Flow Field Analysis

2009 ◽  
Vol 132 (1) ◽  
Author(s):  
Alessandro Armellini ◽  
Filippo Coletti ◽  
Tony Arts ◽  
Christophe Scholtes
Keyword(s):  
Flow Field ◽  
Three Dimensional ◽  
Side Wall ◽  
Field Analysis ◽  
Navier Stokes ◽  
Trailing Edge ◽  
Present Contribution ◽  
Cross Sectional ◽  
Numerical Predictions ◽  
Rib Roughened

The present contribution addresses the aerothermal, experimental, and computational studies of a trapezoidal cross-sectional model simulating a trailing edge cooling cavity with one rib-roughened wall. The flow is fed through tilted slots on one side wall and exits through straight slots on the opposite side wall. The flow field aerodynamics is investigated in Part I of the paper. The reference Reynolds number is defined at the entrance of the test section and set at 67,500 for all the experiments. A qualitative flow model is deduced from surface-streamline flow visualizations. Two-dimensional particle image velocimetry measurements are performed in several planes around midspan of the channel and recombined to visualize and quantify three-dimensional flow features. The crossing-jets issued from the tilted slots are characterized and the jet-rib interaction is analyzed. Attention is drawn to the motion of the flow deflected by the rib-roughened wall and impinging on the opposite smooth wall. The experimental results are compared with the numerical predictions obtained from the finite volume Reynolds-averaged Navier–Stokes solver, CEDRE.

Aero-Thermal Investigation of a Rib-Roughened Trailing Edge Channel With Crossing-Jets: Part I—Flow Field Analysis

2008 ◽  
Author(s):  
Alessandro Armellini ◽  
Filippo Coletti ◽  
Tony Arts ◽  
Christophe Scholtes
Keyword(s):  
Flow Field ◽  
Computational Study ◽  
Three Dimensional ◽  
Side Wall ◽  
Field Analysis ◽  
Trailing Edge ◽  
Present Contribution ◽  
Numerical Predictions ◽  
Flow Features ◽  
Rib Roughened

The present contribution addresses the aero-thermal experimental and computational study of a trapezoidal cross-section model simulating a trailing edge cooling cavity with one rib-roughened wall. The flow is fed through tilted slots on one side wall and exits through straight slots on the opposite side wall. The flow field aerodynamics is investigated in part I of the paper. The reference Reynolds number is defined at the entrance of the test section and set at 67500 for all the experiments. A qualitative flow model is deduced from surface-streamline flow visualizations. Two-dimensional Particle Image Velocimetry measurements are performed in several planes around mid-span of the channel and recombined to visualize and quantify three-dimensional flow features. The jets issued from the tilted slots are characterized and the jet-rib interaction is analyzed. Attention is drawn to the motion of the flow deflected by the rib-roughened wall and impinging on the opposite smooth wall. The experimental results are compared with the numerical predictions obtained from the finite volume, RANS solver CEDRE.

scholarly journals Investigating the Three-Dimensional Microstructural Characteristics of Lithium-Sulfur Electrodes with X-ray Micro-Tomography

2017 ◽  
Vol 77 (11) ◽  
pp. 447-455 ◽  
Author(s):  
Chun Tan ◽  
Sohrab Randjbar Daemi ◽  
Daniel J.L. Brett ◽  
Paul R. Shearing
Keyword(s):  
Three Dimensional ◽  
Microstructural Characteristics ◽  
X Ray ◽  
Micro Tomography ◽  
Lithium Sulfur

Calculation of Flow Induced Vibration Amplitudes of Radial Sewage Water Pumps

2003 ◽  
Author(s):  
Friedrich-Karl Benra ◽  
Hans Josef Dohmen ◽  
Oliver Schneider
Keyword(s):  
Transient Flow ◽  
Three Dimensional ◽  
Sewage Water ◽  
Flow Induced Vibration ◽  
Present Contribution ◽  
Unsteady Forces ◽  
Friction Forces ◽  
Pump Shaft ◽  
Water Pumps ◽  
Operating Points

The extreme vibrations of sewage water pumps with single-blade impellers are induced mainly by interaction of the flow in the impeller and the casing. The resulting periodically unsteady forces affect the impeller and produce radial deflections of the pump shaft. These oscillations of the rotor are transferred to the pump casing and attached pipes. They can be recognized as vibrations at the bearing blocks or at the pump casing. The present contribution describes the investigation of the transient flow in a sewage water pump. The three-dimensional, viscous, unsteady flow in a pump with a single blade impeller is determined by numerical simulation. After that the hydrodynamic stimulation forces are calculated from the so known transient flow field. The forces can be classified into pressure and friction forces. The pressure forces usually exceed the friction forces on several orders of magnitude. A separate view on the fluid-wetted impeller surfaces shows that the pressure forces acting on the blade are clearly larger than the forces at the hub and at the shroud. So they are decisive for the vibration amplitudes of single-blade sewage water pumps. By a following dynamic analysis of the pump rotor using a commercial Finite-Element-Method (FEM) the resulting vibration amplitudes are determined for several operating points. With the known pressure field and the calculated vibration amplitudes the vibration behavior of sewage water pumps can be influenced during the design by changing the relevant construction parameters.

scholarly journals Bio-inspired design of ice-retardant devices based on benthic marine invertebrates: the effect of surface texture

2014 ◽  
Author(s):  
Homayun Mehrabani ◽  
Neil Ray ◽  
Kyle Tse ◽  
Dennis Evangelista
Keyword(s):  
Surface Texture ◽  
Marine Invertebrates ◽  
Freezing Point ◽  
Three Dimensional ◽  
Surface Pattern ◽  
Ice Formation ◽  
Cold Air ◽  
Three Dimensional Printing ◽  
Species Specific ◽  
Effect Of Surface

Growth of ice on surfaces poses a challenge for both organisms and for devices that come into contact with liquids below the freezing point. Resistance of some organisms to ice formation and growth, either in subtidal environments (e.g. Antarctic anchor ice), or in environments with moisture and cold air (e.g.vplants, intertidal) begs examination of how this is accomplished. Several factors may be important in promoting or mitigating ice formation. As a start, here we examine the effect of surface texture alone. We tested four candidate surfaces, inspired by hard-shelled marine invertebrates and constructed using a three-dimensional printing process. We screened biological and artifical samples for ice formation and accretion in submerged conditions using previous methods, and developed a new test to examine ice formation from surface droplets as might be encountered in environments with moist, cold air. It appears surface texture plays only a small role in delaying the onset of ice formation: a stripe feature (corresponding to patterning found on valves of blue mussels,Crassostrea gigas, or on the spines of the Antarctic sea urchinSterechinus neumayeri) slowed ice formation an average of 25% compared to a grid feature (corresponding to patterning found on sub-polar butterclams,Saxidomas nuttali). The geometric dimensions of the features have only a small (~6%) effect on ice formation. Surface texture affects ice formation, but does not explain by itself the large variation in ice formation and species-specific ice resistance observed in other work. This suggests future examination of other factors, such as material elastic properties and coatings, and their interaction with surface pattern.

Interaction between vascular endothelial cells and vascular intimal spindle-shaped cells in vitro

1983 ◽  
Vol 60 (1) ◽  
pp. 89-102
Author(s):  
D de Bono ◽  
C. Green
Keyword(s):  
Extracellular Matrix ◽  
Endothelial Cells ◽  
Vascular Endothelial Cells ◽  
Three Dimensional ◽  
Vascular Endothelial ◽  
Pure Cultures ◽  
Species Specific ◽  
Endothelial Growth Factor

The interactions between human or bovine vascular endothelial cells and fibroblast-like vascular intimal spindle-shaped cells have been studied in vitro, using species-specific antibodies to identify the different components in mixed cultures. Pure cultures of endothelial cells grow as uniform, nonoverlapping monolayers, but this growth pattern is lost after the addition of spindle cells, probably because the extracellular matrix secreted by the latter causes the endothelial cells to modify the way they are attached to the substrate. The result is a network of tubular aggregates of endothelial cells in a three-dimensional ‘polylayer’ of spindle-shaped cells. On the other hand, endothelial cells added to growth-inhibited cultures of spindle-shaped cells will grow in sheets over the surface of the culture. Human endothelial cells grown in contact with spindle-shaped cells have a reduced requirement for a brain-derived endothelial growth factor. The interactions of endothelial cells and other connective tissue cells in vitro may be relevant to the mechanisms of endothelial growth and blood vessel formation in vivo, and emphasize the potential importance of extracellular matrix in controlling endothelial cell behaviour.

Managing the risk from children’s travel cups

2021 ◽  
pp. emermed-2020-210294
Author(s):  
Alice Cameron ◽  
Serryth Dominic Colbert ◽  
Alisdair Macleod ◽  
Harinderjit S Gill
Keyword(s):  
Three Dimensional ◽  
Dental Trauma ◽  
Global Market ◽  
Test Machine ◽  
Body Parts ◽  
Suction Force ◽  
Pullout Force ◽  
Emergency Tracheostomy ◽  
Potential Risks ◽  
Materials Used

IntroductionUK national newspapers have reported cases of children (and adults) who have got their tongue trapped in a Disney travel mug lid, causing extreme distress to the patients, their parents and ED staff. Potential risks include oral endotracheal intubation necessitating emergency tracheostomy to secure the airway, tongue necrosis and dental trauma. Although Disney has withdrawn their original mug from the global market, the same dangers can occur with other internationally available brands. Our aim was to design, test and present an alternative lid.Methods and materialsWe designed an alternative lid to fit onto the original Disney mug; our addition of two parallel bars prevented tongue protrusion into the lid. Prototypes of the original and new lids were three-dimensional printed for testing. A tongue substitute was developed and a representative 0.2 bar suction force was generated. The bottle was mounted in a material test machine, attached to the load cell fixture. Four samples each for the existing and new design were tested. The data were analysed by a custom Matlab script to extract the maximum force required to remove the tongues from the cup.ResultsThe new design resulted in a significant (p=0.0286, Mann-Whitney U) reduction in pullout force. For the existing design, the median pullout force was 4.64 N (minimum 3.86 N, maximum 4.91 N), while it was 2.37 N (minimum 2.20 N, maximum 2.53 N) for the new design. Trauma to the materials used with the original lid design was evident but not observed with our design.ConclusionOur lid appears to offer a safer design that can avoid injuries. However, absolute safety remains unproved, as testing did not account for other body parts which may get trapped in the lid, nor did we test a range of tongue substitute sizes, and laboratory testing only was completed.

Representation and Elaboration of Architectural Perspectives

2017 ◽  
pp. 384-414
Author(s):  
Cristina Càndito
Keyword(s):  
Seventeenth Century ◽  
High Resolution ◽  
Three Dimensional ◽  
Virtual Space ◽  
Present Contribution ◽  
Optical Illusions ◽  
The Real ◽  
Dimensional Models ◽  
Three Dimensional Models ◽  
Architectural Perspective

In the present contribution, the author presents research on the Winter Room of Palazzo Brignole-Sale (Palazzo Rosso) in Genoa, Italy, which is part of the decorative cycle of the Seasons. The cycle displays the peculiar characteristics of the seventeenth-century Genoese decorative style, where architecture, painting, furniture and stuccos are highly interconnected. The research was carried out using the data collected with nodal-photography techniques. Thanks to these techniques, it was to possible to obtain an interactive panoramic spherical photo and high-resolution scaled photos of planar projections of the architectural perspective, in order to identify the real and illusory space. The analysis proceeded with a series of reverse-perspective constructions and the consequent reconstruction (using three-dimensional models) of the possible virtual space represented in the paintings. Thanks to this information, the author was able to carry out the necessary study to understand the peculiar characteristics of the decorations, the optical illusions of which are extremely impressive.

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