Investigation on drag reduction on rotating blade surfaces with microtextures

• Qinsong Zhu,
• Chen Zhang,
• Fuhang Yu and
• Yan Xu

Beilstein J. Nanotechnol. 2024, 15, 833–853, doi:10.3762/bjnano.15.70

• stress, and ρ is the density. where δ is the thickness of the boundary layer. The flow condition around the flat plate wall can be determined by the dimensionless local Reynolds number. where x is the distance from the inlet along the fluid flow direction. For Rex < 3 × 105, the flow in the boundary

• 3, the geometric types and size ranges of the microtextures were determined. Because of the high flow velocity on the blade surface, transverse microtextures would significantly increase the projected area in the flow direction, leading to a drastic increase in Pd. Therefore, longitudinal

Properties of tin oxide films grown by atomic layer deposition from tin tetraiodide and ozone

• Kristjan Kalam,
• Peeter Ritslaid,
• Tanel Käämbre,
• Aile Tamm and
• Kaupo Kukli

Beilstein J. Nanotechnol. 2023, 14, 1085–1092, doi:10.3762/bjnano.14.89

• film thickness profile along the gas flow direction. Analysis of oxygen and iodine contents in the films revealed that above a substrate temperature of 200 °C, the oxygen content remained stable. At temperatures below 200 °C, the oxygen content was significantly higher than that expected from a

A review on slip boundary conditions at the nanoscale: recent development and applications

• Ruifei Wang,
• Jin Chai,
• Bobo Luo,
• Xiong Liu,
• Jianting Zhang,
• Min Wu,
• Mingdan Wei and
• Zhuanyue Ma

Beilstein J. Nanotechnol. 2021, 12, 1237–1251, doi:10.3762/bjnano.12.91

• ][108][109][110], a general expression, which can account for the variation of the effective slip length with the flow direction for arbitrary textures, is still too complicated to derive. Nonetheless, similar to the case of isotropic textures, as stated in Section 2.4.1, approximate equations for some

• limiting cases have been proposed. For periodic alternating stripes with different wettability, it was shown that the maximal and minimal effective slip length can be attained when the stripe orientation is parallel or perpendicular to the streaming flow direction, respectively. Especially, when the stripe

• widths for two-component textures are equal and smaller than the channel height, the variation of the effective slip length with the flow direction is given as follows [111]: where θ indicates the streaming flow direction relative to the stripe orientation, b1 and b2 are the effective slip lengths when

Electrokinetic characterization of synthetic protein nanoparticles

• Daniel F. Quevedo,
• Cody J. Lentz,
• Adriana Coll de Peña,
• Yazmin Hernandez,
• Nahal Habibi,
• Rikako Miki,
• Joerg Lahann and
• Blanca H. Lapizco-Encinas

Beilstein J. Nanotechnol. 2020, 11, 1556–1567, doi:10.3762/bjnano.11.138

• how particles are trapped within the device (inserts). Trapping of SPNP-BSA-488 (c) and of SPNP-BSA-555 (d). Both types of SPNPs were trapped at an applied voltage of 500 V and exhibited a very similar trapping behavior. The flow direction is from the positive to the negative electrode (right to left

Magnetohydrodynamic stagnation point on a Casson nanofluid flow over a radially stretching sheet

• Ganji Narender,
• Kamatam Govardhan and
• Gobburu Sreedhar Sarma

Beilstein J. Nanotechnol. 2020, 11, 1303–1315, doi:10.3762/bjnano.11.114

• transfer are examined. The coordinate system is chosen such that the r-axis is along the direction of the flow whereas the z-axis is perpendicular to the flow direction (Figure 1). The velocity of the outer flow is designated as Ue and the direction of the uniform magnetic field is chosen to be normal to

An investigation on the drag reduction performance of bioinspired pipeline surfaces with transverse microgrooves

• Weili Liu,
• Hongjian Ni,
• Peng Wang and
• Yi Zhou

Beilstein J. Nanotechnol. 2020, 11, 24–40, doi:10.3762/bjnano.11.3

• determine the dimensions of the annular pipe. The annulus’ inner and outer diameter were set to 20 and 34 mm, respectively. The hydraulic diameter of the pipe and annulus were set to D = 14 mm, and the flow direction length of the model to L = 5 × D = 70 mm, according to the suggestion by Eggles [37]. The

• factors on the simulation results, the calculations used the same parameter settings, and the specific conditions were set as follows: (1) The periodic boundary condition was adopted along the flow direction to guarantee the turbulent flow was fully developed. The no-slip boundary condition was adopted

• friction between two liquid interfaces in the bionic pipe flow. In addition, extra frictional drag formed between the vortexes and grooved wall, whose direction was the same as the flow direction. This resulted in the frictional drag having a ‘driving’ effect on the fluid flow. As such, the reduction of

Materials nanoarchitectonics at two-dimensional liquid interfaces

• Katsuhiko Ariga,
• Michio Matsumoto,
• Taizo Mori and
• Lok Kumar Shrestha

Beilstein J. Nanotechnol. 2019, 10, 1559–1587, doi:10.3762/bjnano.10.153

Direct observation of the CVD growth of monolayer MoS₂ using in situ optical spectroscopy

• Claudia Beatriz López-Posadas,
• Yaxu Wei,
• Wanfu Shen,
• Daniel Kahr,
• Michael Hohage and
• Lidong Sun

Beilstein J. Nanotechnol. 2019, 10, 557–564, doi:10.3762/bjnano.10.57

• kinetics can be deduced from the DT spectra. Results and Discussions Ex situ characterization Following the CVD process described in the Experimental section, an MoS2 monolayer was deposited, simultaneously, on not only the surface on the front side (face to the Ar flow direction) but also on the back side

Bidirectional biomimetic flow sensing with antiparallel and curved artificial hair sensors

• Claudio Abels,
• Antonio Qualtieri,
• Toni Lober,
• Alessandro Mariotti,
• Lily D. Chambers,
• Massimo De Vittorio,
• William M. Megill and
• Francesco Rizzi

Beilstein J. Nanotechnol. 2019, 10, 32–46, doi:10.3762/bjnano.10.4

• terms of sensitivity to temperature changes and their response to changes in relative air flow direction. Results: In bidirectional air flow, antiparallel cantilever pairs exhibit an axially symmetrical sensitivity between 40 μV/(m s−1) for the lower air flow velocity range (between ±10–20 m s−1) and 80

• sensor; biomimetics; flow direction; flow sensing; robotics; Introduction Biological lateral line organ Flow sensors in nature often have a morphological polarity, such as the hair cell sensors in the lateral line of fish [1], in jellyfish [2], arthropods [3][4] and crickets [5][6][7][8], as well as the

• sensitivities for the individual cantilever beam lengths were found to be 0.0134, 0.0227 and 0.0284 Ω/(m s−1), respectively. Aiming to detect air flow direction, Wang et al. [39] positioned four microcantilever beams (4000 μm long and 400 μm wide) perpendicular to each other. While air propagated through the

Tailoring polarization and magnetization of absorbing terahertz metamaterials using a cut-wire sandwich structure

• Hadi Teguh Yudistira,
• Shuo Liu,
• Tie Jun Cui and
• Han Zhang

Beilstein J. Nanotechnol. 2018, 9, 1437–1447, doi:10.3762/bjnano.9.136

• °. Magnetization was generated on the cut wire at = 45° at 1.33 THz because an anti-parallel surface current existed on both cut-wires at = 45°. The surface current flow direction at 1.5 THz was opposite to that at 1.31 THz. The scattering parameters (S-parameters) were used to extract the EM properties of the

Surface characterization of nanoparticles using near-field light scattering

• Eunsoo Yoo,
• Yizhong Liu,
• Chukwuazam A. Nwasike,
• Sebastian R. Freeman,
• Brian C. DiPaolo,
• Bernardo Cordovez and
• Amber L. Doiron

Beilstein J. Nanotechnol. 2018, 9, 1228–1238, doi:10.3762/bjnano.9.114

• ) was used to produce the evanescent field by coupling the laser beams into the waveguide with an optical fiber. The samples were drawn through the system and traveled through the nanophotonic trap. The flow direction of the sample is perpendicular to the length of the nanophotonic trap. The flow rate

Perfusion double-channel micropipette probes for oxygen flux mapping with single-cell resolution

• Yang Gao,
• Bin Li,
• Riju Singhal,
• Adam Fontecchio,
• Ben Pelleg,
• Zulfiya Orynbayeva,
• Yury Gogotsi and
• Gary Friedman

Beilstein J. Nanotechnol. 2018, 9, 850–860, doi:10.3762/bjnano.9.79

• represents roughly the diffusion boundary of the florescent dye. The arrows show the fluid flow direction. A constant withdraw rate of 5 µL/min is applied by a syringe pump to the pipette’s extraction channel. The injection pressure was increased from 100 hPa to 116 hPa with an increment of 2–3 hPa and then

Engineering of oriented carbon nanotubes in composite materials

• Razieh Beigmoradi,
• Abdolreza Samimi and
• Davod Mohebbi-Kalhori

Beilstein J. Nanotechnol. 2018, 9, 415–435, doi:10.3762/bjnano.9.41

• solution and a nozzle to control the N2 flow direction on the Si substrate. SEM image of aligned CNTs is reproduced with permission from [95], copyright 2005 American Institute of Physics. Schematic structure of a liquid crystal (blue ellipsoids) and CNT (black cylinders) rearrangement under an external

Atomic layer deposition and properties of ZrO₂/Fe₂O₃ thin films

• Kristjan Kalam,
• Helina Seemen,
• Peeter Ritslaid,
• Mihkel Rähn,
• Aile Tamm,
• Kaupo Kukli,
• Aarne Kasikov,
• Joosep Link,
• Raivo Stern,
• Salvador Dueñas,
• Helena Castán and
• Héctor García

Beilstein J. Nanotechnol. 2018, 9, 119–128, doi:10.3762/bjnano.9.14

• than individual Fe2O3 or ZrO2, varying around 0.1 nm/cycle (Figure 1). The thickness (growth rate) profiles along the gas flow direction may be regarded as characteristic of cross-flow atomic layer deposition reactors, in which the substrate holder is designed in a way that leaves one edge of the

• (subjected to magnetometry) and TiN substrates (subjected to electrical measurements). The range of cation ratios is due to the variation of the ratios measured at different locations on the substrate holder and are due to the film thickness growth rate profiles along the gas flow direction. In these

Localized growth of carbon nanotubes via lithographic fabrication of metallic deposits

• Fan Tu,
• Martin Drost,
• Imre Szenti,
• Janos Kiss,
• Zoltan Kónya and
• Hubertus Marbach

Beilstein J. Nanotechnol. 2017, 8, 2592–2605, doi:10.3762/bjnano.8.260

• the flow direction. The SEM image with high magnification on the lifted-up flake (Figure 8c on the right) reveals different morphologies of the CNTs on top and below the flake. An EDX spectrum was obtained at position 1 as indicated in Figure 8b with the direction of electron beam parallel to the

• is not determined by the flow direction but by the position of the initially lifted corner. Since the top side of the flake is accessible to precursor molecules, the CNT growth can occur in a parallel fashion on both sides of the flake, yielding the structures depicted in Figure 7 and Figure 8. Co

Ferrocholesteric–ferronematic transitions induced by shear flow and magnetic field

• Dmitriy V. Makarov,
• Alexander A. Novikov and
• Alexander N. Zakhlevnykh

Beilstein J. Nanotechnol. 2017, 8, 2552–2561, doi:10.3762/bjnano.8.255

• sample. Such a flow leads to the aligning of LC molecules in the shear plane at an angle φ0 with respect to the flow direction, which in the coordinate system under consideration is determined by the relation [24]: where λ = −γ2/γ1 is the reactive parameter (λ > 0 in an LC composed of rod-shaped

Numerical investigation of the tribological performance of micro-dimple textured surfaces under hydrodynamic lubrication

• Kangmei Li,
• Dalei Jing,
• Jun Hu,
• Xiaohong Ding and
• Zhenqiang Yao

Beilstein J. Nanotechnol. 2017, 8, 2324–2338, doi:10.3762/bjnano.8.232

• Figure 2. The origin of the coordinate system is located on the revolution axis of the micro-dimple and is h0/2 away from the upper surface. The x, y and z axes are defined as the direction vertical to the symmetry plane, the flow direction and the direction of lubrication film thickness, respectively. l

Analysis of self-heating of thermally assisted spin-transfer torque magnetic random access memory

• Austin Deschenes,
• Sadid Muneer,
• Mustafa Akbulut,
• Ali Gokirmak and
• Helena Silva

Beilstein J. Nanotechnol. 2016, 7, 1676–1683, doi:10.3762/bjnano.7.160

• simulated as the thermal effect is mainly of interest for current flow direction and resistance state combinations that result in device switching. Partial inclusion of the different self-heating mechanisms in the simulations shows the relative importance of each (Figure 9). The largest contributor to

Aquatic versus terrestrial attachment: Water makes a difference

• Petra Ditsche and
• Adam P. Summers

Beilstein J. Nanotechnol. 2014, 5, 2424–2439, doi:10.3762/bjnano.5.252

• ). Moreover, aquatic flows are often variable in magnitude and direction on very short time scales. In running waters and some directed marine currents there is a general main flow direction, while the waves in the marine intertidal move the water in different directions with high frequency. In many cases

The study of surface wetting, nanobubbles and boundary slip with an applied voltage: A review

• Yunlu Pan,
• Bharat Bhushan and
• Xuezeng Zhao

Beilstein J. Nanotechnol. 2014, 5, 1042–1065, doi:10.3762/bjnano.5.117

• on the properties of the fluid and surface, rather than the channel size and the flow direction, the relationship between Σ and ξ can be expressed as [88][89]: where κ is the Debye length, kB is the Boltzmann constant, T is the absolute temperature, z is the chemical valence of ions, e is the

Dynamics of capillary infiltration of liquids into a highly aligned multi-walled carbon nanotube film

• Sławomir Boncel,
• Krzysztof Z. Walczak and
• Krzysztof K. K. Koziol

Beilstein J. Nanotechnol. 2011, 2, 311–317, doi:10.3762/bjnano.2.36

• the HACNT film; central part – a side-view magnification showing degree of alignment. A dashed arrow indicates the flow direction of tested liquids, opposite to the growth direction of the HACNT array. Sequence of images showing infiltration of the HACNT film, as grown on the quartz substrate, by

Determination of object position, vortex shedding frequency and flow velocity using artificial lateral line canals

• Adrian Klein and
• Horst Bleckmann

Beilstein J. Nanotechnol. 2011, 2, 276–283, doi:10.3762/bjnano.2.32

• exhibited a sensitivity of about 200 μm/s flow velocity, a bandwidth of about 1 kHz, and, due to its small dimensions, a reduced interference with the flow field and with the neighbouring anemometers. Unfortunately, hot wire anemometers cannot discern flow direction. As a result, they only provide a

Biomimetics inspired surfaces for drag reduction and oleophobicity/philicity

• Bharat Bhushan

Beilstein J. Nanotechnol. 2011, 2, 66–84, doi:10.3762/bjnano.2.9

• grooves (aligned parallel to the local flow direction of the water) (Figure 1b). These grooved scales reduce vortice formation present on a smooth surface, resulting in water moving efficiently over their surface [2][19][20][21][22]. The water surrounding these complex structures can lead to protection

• , and low adhesion. An aquatic animal, such as a shark, is another model from nature. Shark skin is covered by very small individual tooth-like scales called dermal denticles (little skin teeth), ribbed with longitudinal grooves (aligned parallel to the local flow direction of the water). These grooved