Improved Aerodynamic Efficiency through Active Surface Patterns

ATZ worldwide ◽  
2021 ◽  
Vol 124 (1) ◽  
pp. 60-64
Author(s):  
Nils Ballerstein ◽  
Frank Götzke ◽  
Peter Horst
Keyword(s):  
Active Surface ◽  
Aerodynamic Efficiency ◽  
Surface Patterns

Tenacious Mass Transfer Limitations Drive Catalytic Selectivity during Electrochemical Carbon Dioxide Reduction

2019 ◽  
Author(s):  
Kailun Yang ◽  
Recep Kas ◽  
Wilson A. Smith
Keyword(s):  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Catalyst Layer ◽  
Active Surface ◽  
Active Surface Area ◽  
High Concentration ◽  
Copper Electrodes ◽  
Surface Enhanced ◽  
Local Current

<p>This study evaluated the performance of the commonly used strong buffer electrolytes, i.e. phosphate buffers, during CO<sub>2</sub> electroreduction in neutral pH conditions by using in-situ surface enhanced infrared absorption spectroscopy (SEIRAS). Unfortunately, the buffers break down a lot faster than anticipated which has serious implications on many studies in the literature such as selectivity and kinetic analysis of the electrocatalysts. Increasing electrolyte concentration, surprisingly, did not extend the potential window of the phosphate buffers due to dramatic increase in hydrogen evolution reaction. Even high concentration phosphate buffers (1 M) break down within the potentials (-1 V vs RHE) where hydrocarbons are formed on copper electrodes. We have extended the discussion to high surface area electrodes by evaluating electrodes composed of copper nanowires. We would like highlight that it is not possible to cope with high local current densities on these high surface area electrodes by using high buffer capacity solutions and the CO<sub>2</sub> electrocatalysts are needed to be evaluated by casting thin nanoparticle films onto inert substrates as commonly employed in fuel cell reactions and up to now scarcely employed in CO<sub>2</sub> electroreduction. In addition, we underscore that normalization of the electrocatalytic activity to the electrochemical active surface area is not the ultimate solution due to concentration gradient along the catalyst layer.This will “underestimate” the activity of high surface electrocatalyst and the degree of underestimation will depend on the thickness, porosity and morphology of the catalyst layer. </p> <p> </p>

Babbitt’s Beguiling Surfaces, Improvised Inside; Part III: Opportunities

2019 ◽  
Vol 5 (3) ◽  
Author(s):  
Joshua Banks Mailman
Keyword(s):  
Music Composition ◽  
Jazz Improvisation ◽  
The Third ◽  
Partial Orderings ◽  
Compositional Structures ◽  
Surface Patterns ◽  
Inside Part ◽  
Musical Activities

Babbitt’s relatively early composition Semi-Simple Variations (1956) presents intriguing surface patterns that are not determined by its pre-compositional plan, but rather result from subsequent “improvised” decisions that are strategic. This video (the third of a three-part video essay) considers Babbitt’s own conversational pronouncements (in radio interviews) together with some particulars of his life-long musical activities, that together suggest uncanny affiliations to jazz improvisation. As a result of Babbitt’s creative reconceptualizing of planning and spontaneity in music, his pre-compositional structures (partial orderings) fit in an unexpected way into (or reformulate) the ecosystem relating music composition to the physical means of its performance.

Application of Automated FIB for TEM Sample Preparation in Semiconductor Failure Analysis

2014 ◽  
Author(s):  
Jie Zhu ◽  
Soo Sien Seah ◽  
Irene Tee ◽  
Bing Hai Liu ◽  
Eddie Er ◽  
...  
Keyword(s):  
Sample Preparation ◽  
Success Rate ◽  
Protective Layer ◽  
Factors Affecting ◽  
Dual Beam ◽  
Lamella Thickness ◽  
Surface Patterns ◽  
Working Parameters ◽  
Practical Factors ◽  
High Flexibility

Abstract In this paper, we describe automated FIB for TEM sample preparation using iFast software on a Helios 450HP dual-beam system. A robust iFast automation recipe needs to consider as many variables as possible in order to ensure consistent sample quality and high success rate. Variations mainly come from samples of different materials, structures, surface patterns, surface topography and surface charging. The recipe also needs to be user-friendly and provide high flexibility by allowing users to choose preferable working parameters for specific types of samples, such as: grounding, protective layer coating, milling steps, and final TEM lamella thickness/width. In addition to the iFast recipe, other practical factors affecting automation success rate are also discussed and highlighted.

The Role of Saline Aerosols in the Prevention and Therapy of Cardio-respiratory and Osteo-muscular Afflictions

2018 ◽  
Vol 69 (10) ◽  
pp. 2826-2832
Author(s):  
Ioan Gabriel Sandu ◽  
Viorica Vasilache ◽  
Andrei Victor Sandu ◽  
Marin Chirazi ◽  
Cezar Honceriu ◽  
...  
Keyword(s):  
Athletic Performance ◽  
Gaseous Medium ◽  
Human Subjects ◽  
Active Surface ◽  
Positive Influence ◽  
Climatic Parameters ◽  
Gaussian Distributions ◽  
Gaseous Media ◽  
Source Number

The saline aerosols generated in gaseous media, as nanodispersions, behave, with respect to the concentration levels and the lifespan, as trimodal distributions (the three domains with Gaussian distributions: fine or Aitken under 50 �m, medium between 50 and 500 mm and, respectively, coarse or large between 500 and 1000 mm). The generation in latent state is dependent on the active surface of the source (number of generator centres, the size and position of the fluorescences, the porosity, size and shape of the source, etc.), the climatic parameters, but also on a series of other characteristics of the gaseous medium. Our team has demonstrated experimentally that saline aerosols, NaCl type, besides the ability to prevent and treat broncho-respiratory and cardiac conditions, through coassistance of saline aerosols of other cations than sodium, and of the iodine anion, have for certain levels of concentrations propitious effects over the immune, bone and muscular systems. Similarly proved has been the positive influence on the development of children, as well the determinant role in increasing athletic performance and of other human subjects performing intense activities.

Transient convective diffusion to a uniformly accessible surface under aparent slip conditions

1991 ◽  
Vol 56 (2) ◽  
pp. 334-343
Author(s):  
Ondřej Wein
Keyword(s):  
Power Law ◽  
Analytical Solutions ◽  
Convective Diffusion ◽  
Active Surface ◽  
Velocity Profiles ◽  
One Dimensional ◽  
Slip Conditions ◽  
Accessible Surface ◽  
Diffusion Problems

Analytical solutions are given to a class of unsteady one-dimensional convective-diffusion problems assuming power-law velocity profiles close to the transport-active surface.

Electronic and Vibrational Properties of Single Crystal Surfaces of NiAl

1986 ◽  
Vol 83 ◽  
Author(s):  
S.-C. Lui ◽  
J. M. Mundenar ◽  
E. W. Plummer ◽  
M. E. Mostoller ◽  
R. M. Nicklow ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Nearest Neighbor ◽  
Surface States ◽  
Active Surface ◽  
Atomic Displacement ◽  
Inelastic Electron ◽  
Crystal Surfaces ◽  
Single Crystal Surfaces ◽  
Nial Alloy ◽  
Bulk Surface

ABSTRACTSurface and bulk electronic structure of the ordered NiAl alloy were measured using angle resolved photoelectron spectroscopy. The measured bulk d-bands (Ni like) were observed to be narrower than theoretically calculated d band widths which are 20 to 40% wider (depending upon what is used as a measure of the width). At least two surface states were observed on both the (110) and (111) surfaces. The nature of these surface states and their relationship to the bulk band structure is discussed. Dispersion of bulk phonons was measured by neutron scattering and fitted with a fourth nearest neighbor Born-von Karman model. Dipole active surface phonons on the (110) and (111) surfaces were observed by inelastic electron scattering and the frequencies also calculated assuming a truncated bulk surface. The calculated surface modes present a qualitative picture of the atomic displacement at each surface and also show that the surface phonon energy and intensity depends upon the structure of the surface.

scholarly journals Hydrolytic Modification of SiO2 Microspheres with Na2SiO3 and the Performance of Supported Nano-TiO2 Composite Photocatalyst

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2553
Author(s):  
Yu Tu ◽  
Weihua Ao ◽  
Chunhong Wang ◽  
Tianyu Ren ◽  
Lijuan Zhang ◽  
...  
Keyword(s):  
Sol Gel ◽  
Active Surface ◽  
Hydroxyl Groups ◽  
Nano Tio2 ◽  
Amorphous Sio2 ◽  
Composite Photocatalyst ◽  
Sio2 Shell ◽  
Functional Efficiency ◽  
Sio2 Microspheres ◽  
Better Than

Modified microspheres (SiO2-M) were obtained by the hydrolytic modification of silicon dioxide (SiO2) microspheres with Na2SiO3, and then, SiO2-M was used as a carrier to prepare a composite photocatalyst (SiO2-M/TiO2) using the sol-gel method; i.e., nano-TiO2 was loaded on the surface of SiO2-M. The structure, morphology, and photocatalytic properties of SiO2-M/TiO2 were investigated. Besides, the mechanism of the effect of SiO2-M was also explored. The results show that the hydrolytic modification of Na2SiO3 coated the surface of SiO2 microspheres with an amorphous SiO2 shell layer and increased the quantity of hydroxyl groups. The photocatalytic performance of the composite photocatalyst was slightly better than that of pure nano-TiO2 and significantly better than that of the composite photocatalyst supported by unmodified SiO2. Thus, increasing the loading capacity of nano-TiO2, improving the dispersion of TiO2, and increasing the active surface sites are essential factors for improving the functional efficiency of nano-TiO2. This work provides a new concept for the design of composite photocatalysts by optimizing the performance of the carrier.

scholarly journals Osseointegrating and phase-oriented micro-arc-oxidized titanium dioxide bone implants

2021 ◽  
Vol 19 ◽  
pp. 228080002110068
Author(s):  
Hsien-Te Chen ◽  
Hsin-I Lin ◽  
Chi-Jen Chung ◽  
Chih-Hsin Tang ◽  
Ju-Liang He
Keyword(s):  
Titanium Dioxide ◽  
High Surface ◽  
Cell Activity ◽  
Active Surface ◽  
Rutile Phase ◽  
Hydroxyl Groups ◽  
Bone Implant ◽  
Implant System

Here, we present a bone implant system of phase-oriented titanium dioxide (TiO2) fabricated by the micro-arc oxidation method (MAO) on β-Ti to facilitate improved osseointegration. This (101) rutile-phase-dominant MAO TiO2 (R-TiO2) is biocompatible due to its high surface roughness, bone-mimetic structure, and preferential crystalline orientation. Furthermore, (101) R-TiO2 possesses active and abundant hydroxyl groups that play a significant role in enhancing hydroxyapatite formation and cell adhesion and promote cell activity leading to osseointegration. The implants had been elicited their favorable cellular behavior in vitro in the previous publications; in addition, they exhibit excellent shear strength and promote bone–implant contact, osteogenesis, and tissue formation in vivo. Hence, it can be concluded that this MAO R-TiO2 bone implant system provides a favorable active surface for efficient osseointegration and is suitable for clinical applications.

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