Effect of magnetic field, heat generation and absorption on nanofluid flow over a nonlinear stretching sheet

• Santoshi Misra and
• Govardhan Kamatam

Beilstein J. Nanotechnol. 2020, 11, 976–990, doi:10.3762/bjnano.11.82

• the nanoparticle material and the base fluid. In Equations 1–4, u, and v denote the velocity components along x and y axes, respectively, ρf is the base fluid density, a is a positive constant, DB is the Brownian diffusion coefficient, DT denotes the thermodiffusion coefficient, c is the volumetric

A Josephson junction based on a highly disordered superconductor/low-resistivity normal metal bilayer

• Pavel M. Marychev and
• Denis Yu. Vodolazov

Beilstein J. Nanotechnol. 2020, 11, 858–865, doi:10.3762/bjnano.11.71

• a single S layer if the thickness of the S and the N layers are about the superconducting coherence length [15]. Because of the large diffusion coefficient, DN ≫ DS, the N layer provides both a large phase concentration in the constriction leading to a single-valued current–phase relation (CPR) and

• of the superconductor. As we show below, the presence of a relatively thick N layer with large diffusion coefficient and small minigap in the electron spectra provides efficient cooling of the constriction. To estimate the increase of temperature in the resistive state we use a two-temperature (2T

Transition from freestanding SnO₂ nanowires to laterally aligned nanowires with a simulation-based experimental design

• Jasmin-Clara Bürger,
• Sebastian Gutsch and
• Margit Zacharias

Beilstein J. Nanotechnol. 2020, 11, 843–853, doi:10.3762/bjnano.11.69

• presents the pressure and temperature dependence of the diffusion coefficient D, and Equation 2 describes the covered distance as a function of time, t, adapted from [28]: where T and p are the process temperature and the process pressure, respectively, and Dn is the tabular value of the diffusion

• coefficient at standard conditions. The general transport equation is described by the following Equation 3 [28]: where ρ is the density, c is the vapor concentration, time t, carrier gas velocity u, diffusion coefficient D and external vapor sources R. In Equation 3, the first term on the left-hand-side

• convection [28]. The diffusion coefficient depends on the process pressure, and additionally, convection is also governed by the total incoming volumetric flow rate [28]. In case of a higher volumetric flow, the influence of the convection as compared to the diffusion increases (Figure 2 and Figure 3). For

Comparison of fresh and aged lithium iron phosphate cathodes using a tailored electrochemical strain microscopy technique

• Matthias Simolka,
• Hanno Kaess and
• Kaspar Andreas Friedrich

Beilstein J. Nanotechnol. 2020, 11, 583–596, doi:10.3762/bjnano.11.46

• and aged LiMnO2 cathodes and found a decrease of the diffusion coefficient in the aged sample due to structural degradation of the material [30]. Zhu et al. studied the degradation of LiNi0.3Co0.3Mn0.3O2 by ESM and showed a decrease in the ESM amplitude over the ageing of the cathode material, which

• reaction model [56][65][78]. This faulty assumption affects the diffusion coefficients extracted from the experimental data. Additionally, the preparation of the material influences the diffusion coefficient [75][77]. The assumed 10 nm of probed depth is a reasonable assumption considering the sharp

• boundaries observed in the ESM signals. Smaller values for the probed depth are however possible, which would change the diffusion coefficients by one or two orders of magnitude. Regarding the comparison of fresh and aged diffusion coefficient distributions, the minor differences between the fresh and aged

Nanoparticles based on the zwitterionic pillar[5]arene and Ag⁺: synthesis, self-assembly and cytotoxicity in the human lung cancer cell line A549

• Dmitriy N. Shurpik,
• Denis A. Sevastyanov,
• Pavel V. Zelenikhin,
• Pavel L. Padnya,
• Vladimir G. Evtugyn,
• Yuriy N. Osin and
• Ivan I. Stoikov

Beilstein J. Nanotechnol. 2020, 11, 421–431, doi:10.3762/bjnano.11.33

•  1, Table S3). Figure 4 shows that the diffusion coefficients for pillar[5]arene 3 and 3/Ag+ nanoparticles are different. The self-diffusion coefficient of pillar[5]arene 3 is greater (D = 4.22 × 10–10 m2 s−1), which indicates its greater mobility in solution in comparison with 3/Ag+ associates. This

• is consistent with the fact that the molecular weight of 3/Ag+ is greater than the molecular weight of pillar[5]arene 3. When a small amount of Ag+ (c(Ag+)/c(3) = 0.5) is added to the pillar[5]arene 3 solution, its self-diffusion coefficient sharply decreases (D = 3.75 × 10−10 m2 s−1), which

• indicates a decrease in mobility pillar[5]arene due to the formation of the associate. The minimum diffusion coefficient is observed at c(Ag+)/c(3) = 1 (D = 3.19 × 10−10 m2 s−1). With an increase in the Ag+ concentration, the self-diffusion coefficients equalize (Figure 4). With a further increase in the Ag

Anomalous current–voltage characteristics of SFIFS Josephson junctions with weak ferromagnetic interlayers

• Tairzhan Karabassov,
• Anastasia V. Guravova,
• Aleksei Yu. Kuzin,
• Elena A. Kazakova,
• Shiro Kawabata,
• Boris G. Lvov and
• Andrey S. Vasenko

Beilstein J. Nanotechnol. 2020, 11, 252–262, doi:10.3762/bjnano.11.19

• where τm ≡ τz is the magnetic scattering time. In the superconducting layer S the Usadel equation reads [94] Here Ds is the diffusion coefficient in the S layer and Δ(x) is the pair potential in the superconductor. We note that Δ(x) vanishes in the F layer. Equation 3 and Equation 4 must be supplemented

Fully amino acid-based hydrogel as potential scaffold for cell culturing and drug delivery

• Dávid Juriga,
• Evelin Sipos,
• Orsolya Hegedűs,
• Gábor Varga,
• Miklós Zrínyi,
• Krisztina S. Nagy and
• Angéla Jedlovszky-Hajdú

Beilstein J. Nanotechnol. 2019, 10, 2579–2593, doi:10.3762/bjnano.10.249

• diffusion coefficient in the gel matrix and consequently to a faster drug release. A similar observation was described in the case of another PASP-based gel and different other types of hydrogels [34]. For the PASP-20CYS-LYS gel, the drug release kinetics do not differ significantly for the reductive medium

A novel all-fiber-based LiFePO₄/Li₄Ti₅O₁₂ battery with self-standing nanofiber membrane electrodes

• Li-li Chen,
• Hua Yang,
• Mao-xiang Jing,
• Chong Han,
• Fei Chen,
• Xin-yu Hu,
• Wei-yong Yuan,
• Shan-shan Yao and
• Xiang-qian Shen

Beilstein J. Nanotechnol. 2019, 10, 2229–2237, doi:10.3762/bjnano.10.215

• for electric and hybrid vehicles due to their stable discharge potential, good cycling stability and environmental friendliness [24][25][26]. However, both of them have the disadvantages of low Li+ diffusion coefficient and poor electronic conductivity, which limit the practical applications in LIBs

BergaCare SmartLipids: commercial lipophilic active concentrates for improved performance of dermal products

• Florence Olechowski,
• Rainer H. Müller and
• Sung Min Pyo

Beilstein J. Nanotechnol. 2019, 10, 2152–2162, doi:10.3762/bjnano.10.208

• with water. Controlled release is not possible due to the high diffusion coefficient, D, in oils of low viscosity (Einstein equation). Release typically takes place very fast within seconds or milliseconds [1]. The age of smart delivery systems for skin started with the introduction of liposomes to the

• mPa·s) and phospholipid bilayers (184 mPa·s [15]), this process takes place relatively fast. The diffusion coefficient D can be calculated using the Einstein equation: with kB being the Boltzmann constant and T being the absolute temperature. In contrast, the viscosity η in solid particles is very high

Synthesis of highly active ETS-10-based titanosilicate for heterogeneously catalyzed transesterification of triglycerides

• Muhammad A. Zaheer,
• David Poppitz,
• Khavar Feyzullayeva,
• Marianne Wenzel,
• Jörg Matysik,
• Radomir Ljupkovic,
• Aleksandra Zarubica,
• Alexander A. Karavaev,
• Andreas Pöppl,
• Roger Gläser and
• Muslim Dvoyashkin

Beilstein J. Nanotechnol. 2019, 10, 2039–2061, doi:10.3762/bjnano.10.200

• discussed scenarios are illustrated in Figure 17 with representation of the respective diffusion modes. To the best of our knowledge, this study represents the first direct measurement of the self-diffusion coefficient of (any) triglyceride or oil (as their mixture) confined to nanopores of (any) catalyst

• hydrophobicity. Additionally, the hydrophobicity of the outer crystal surface is expected to be restored after calcination, adding to the resulting activity of the C-P-ETS-10/60 catalyst. Using the obtained self-diffusion coefficient of pure triolein inside the mesopores of C-P-ETS-10 at 403 K, a simple estimate

• size (scanning electron microscopy, laser diffraction), textural properties (N2 sorption, Hg porosimetry), presence of hydroxyl groups and active sites (temperature-programmed desorption of NH3 and CO2, 29Si magic angle spinning nuclear magnetic resonance (NMR)), mesopore accessibility and diffusion

Gold-coated plant virus as computed tomography imaging contrast agent

• Alaa A. A. Aljabali,
• Mazhar S. Al Zoubi,
• Khalid M. Al-Batanyeh,
• Ali Al-Radaideh,
• Mohammad A. Obeid,
• Abeer Al Sharabi,
• Walhan Alshaer,
• Bayan AbuFares,
• Tasnim Al-Zanati,
• Murtaza M. Tambuwala,
• Naveed Akbar and
• David J. Evans

Beilstein J. Nanotechnol. 2019, 10, 1983–1993, doi:10.3762/bjnano.10.195

• DLS measurements were carried out per sample after 2 min waiting time to allow the solutions to be at rest. The hydrodynamic radius (intensity particle size distribution was used for all measurements) was calculated by the instrument from the translational diffusion coefficient using the Stokes

Glucose-derived carbon materials with tailored properties as electrocatalysts for the oxygen reduction reaction

• Rafael Gomes Morais,
• Natalia Rey-Raap,
• José Luís Figueiredo and
• Manuel Fernando Ribeiro Pereira

Beilstein J. Nanotechnol. 2019, 10, 1089–1102, doi:10.3762/bjnano.10.109

• kinetic current density (mA cm-2), ω is the electrode rotation rate (rpm) and B represents the Levich constant related to the diffusion limiting current density given by Equation 2. In Equation 2, F is the Faraday constant (96 486 C mol−1), D is the diffusion coefficient of O2 (1.95 × 10−5 cm2 s−1), ν is

Periodic Co/Nb pseudo spin valve for cryogenic memory

• Nikolay Klenov,
• Yury Khaydukov,
• Sergey Bakurskiy,
• Roman Morari,
• Igor Soloviev,
• Vladimir Boian,
• Thomas Keller,
• Mikhail Kupriyanov,
• Anatoli Sidorenko and
• Bernhard Keimer

Beilstein J. Nanotechnol. 2019, 10, 833–839, doi:10.3762/bjnano.10.83

• ,p = 0 in nonferromagnetic materials), TC is the critical temperature of the superconductor, ξp = (Dp/2πTC)1/2 is the coherence length, Dp is the diffusion coefficient, Gp and Φp are the normal and anomalous Green’s functions, respectively, is the suppression parameter, RBpq and are the resistance

Defect formation in multiwalled carbon nanotubes under low-energy He and Ne ion irradiation

• Santhana Eswara,
• Jean-Nicolas Audinot,
• Brahime El Adib,
• Maël Guennou,
• Tom Wirtz and
• Patrick Philipp

Beilstein J. Nanotechnol. 2018, 9, 1951–1963, doi:10.3762/bjnano.9.186

• gas species have been taken from previous work [43]. For He, a diffusion coefficient of 4.8 × 10−6 cm2 s−1 was used, and for Ne a value of 1.1 × 10−6 cm2 s−1. The irradiation was simulated for 25 keV ion impacts at normal incidence with a fluence of up to 1018 ions/cm2 which corresponds to the

Increasing the performance of a superconducting spin valve using a Heusler alloy

• Andrey A. Kamashev,
• Aidar A. Validov,
• Joachim Schumann,
• Vladislav Kataev,
• Bernd Büchner,
• Yakov V. Fominov and
• Ilgiz A. Garifullin

Beilstein J. Nanotechnol. 2018, 9, 1764–1769, doi:10.3762/bjnano.9.167

• path lS, the diffusion coefficient of conduction electrons DS and the superconducting coherence length The same procedure can be applied for the F layers taking into account the definition of the superconducting coherence length in the F layers [29], where DF is the diffusion coefficient for the

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

• hydrodynamically confined to the flow. The time that it takes a molecule to diffuse across the section of length b along the flow is b2/D, where D is the diffusion coefficient, and the time it takes the flow to cross the same distance is roughly b/v, where v is the flow velocity. Taking the ratio of these times

• velocity increases do not amplify the signal. This logic can provide a rough estimate of the perfusion velocity range beyond which no signal is gained. As an example, we consider a pipette that is located at dd = 10 μm from the substrate. Taking the oxygen diffusion coefficient of 2000 µm2/s and assuming

• is the pressure, is the unit vector, μ is the dynamic viscosity, and is the volume force field. Another study solved the convection diffusion equations (Equation 4 and Equation 5) for concentration distribution [45][46]: Where D is the diffusion coefficient, c is the species mass concentration, is

The nanofluidic confinement apparatus: studying confinement-dependent nanoparticle behavior and diffusion

• Stefan Fringes,
• Felix Holzner and
• Armin W. Knoll

Beilstein J. Nanotechnol. 2018, 9, 301–310, doi:10.3762/bjnano.9.30

• approximation (CSA) to calculate the hindered lateral diffusion in a fluidic slit. A third approximation, the matched asymptotic expansion (MAE), is not considered here as it deviates only slightly from the LSA. The diffusion coefficient of a freely moving spherical particle obeys the Stokes–Einstein-equation

• by the sum of the contributions. Anoher expression, the CSA includes multiple interactions of the perturbations of the pressure and velocity fields induced by each wall. The same interactions with the colloid are not included [15][31]. The lateral diffusion coefficient D||2 can be measured from the

• mean squared displacement (MSD) in one of the orthogonal directions x or y. For the x-direction and a time interval Δt, the MSD is given by where signifies the ensemble average, N is the number of observed positions per trajectory, Kα is a generalized diffusion coefficient and α is the anomalous

Synthesis and characterization of electrospun molybdenum dioxide–carbon nanofibers as sulfur matrix additives for rechargeable lithium–sulfur battery applications

• Ruiyuan Zhuang,
• Shanshan Yao,
• Maoxiang Jing,
• Xiangqian Shen,
• Jun Xiang,
• Tianbao Li,
• Kesong Xiao and
• Shibiao Qin

Beilstein J. Nanotechnol. 2018, 9, 262–270, doi:10.3762/bjnano.9.28

• 850 °C delivered optimal performance, with an initial capacity of 1095 mAh g−1 and retained a capacity of 860 mAh g−1 after 50 cycles. The results demonstrated that the sulfur/MoO2–CNF composite displays a markedly high lithium-ion diffusion coefficient, a low interfacial resistance and much better

• sulfur and MoO2–CNF materials. This suggested sufficient contact among sulfur and MoO2–CNFs, which lowered the resistance for the electron transfer across the interface between both. For further confirmation, the lithium ion diffusion coefficient was calculated using Equation 2 [40][41]: where DLi

• represents the diffusion coefficient of the lithium ion, R is the gas constant, T is the absolute temperature, A is the surface area of electrode, n is the number of electrons per molecule during the reaction, F is the Faraday constant, C is the concentration of lithium ions, and σ is the Warburg factor

Impact of titanium dioxide nanoparticles on purification and contamination of nematic liquid crystals

• Dmitrii Pavlovich Shcherbinin and
• Elena A. Konshina

Beilstein J. Nanotechnol. 2017, 8, 2766–2770, doi:10.3762/bjnano.8.275

• by plasma synthesis and were not covered with any ligands. Dry NPs were added to LCs at a concentration of 0.25, 0.5 and 1 wt %. The composites were prepared in isotropic phase over one hour by ultrasonication. To estimate ion density (c) and average diffusion coefficient (D) in LC1, LC2 and their

• ]: where сi – ion density, q – elementary charge, D – average diffusion coefficient, ε0 – dielectric constant, d – thickness of the cell gap, kB – Boltzmann factor, T – temperature, f – frequency, and ε∞ – high-frequency dielectric permittivity. We have evaluated the ion density and the average diffusion

• concentration is reduced almost twice by doping with 1 wt % TiO2 NPs. In both cases, the increase of concentration leads to an increasing diffusion coefficient. Moreover, the estimated diffusion coefficient of ions in LC2 was larger. In the framework of Garbovskiy’s theory, the surface of the NP is considered

Substrate and Mg doping effects in GaAs nanowires

• Perumal Kannappan,
• Nabiha Ben Sedrine,
• Jennifer P. Teixeira,
• Maria R. Soares,
• Bruno P. Falcão,
• Maria R. Correia,
• Nestor Cifuentes,
• Emilson R. Viana,
• Marcus V. B. Moreira,
• Geraldo M. Ribeiro,
• Alfredo G. de Oliveira,
• Juan C. González and
• Joaquim P. Leitão

Beilstein J. Nanotechnol. 2017, 8, 2126–2138, doi:10.3762/bjnano.8.212

• [23][24]. Be has been the main choice to produce p-type GaAs layers and nanowires grown by molecular beam epitaxy (MBE) [25][26][27][28]. However, severe drawbacks like segregation at high concentration, a large diffusion coefficient prohibiting abrupt doping profiles and high toxicity have motivated

• research for alternatives [29][30][31][32]. Mg is another dopant impurity [25][33][34][35][36][37][38] used for p-type doping with a low diffusion coefficient, which has a solid solubility of 1 × 1019 cm−3 and a low sticking coefficient (10−2–10−5) in the substrate temperature range of 725–850 K [34]. The

Bi-layer sandwich film for antibacterial catheters

• Gerhard Franz,
• Florian Schamberger,
• Hamideh Heidari Zare,
• Sara Felicitas Bröskamp and
• Dieter Jocham

Beilstein J. Nanotechnol. 2017, 8, 1982–2001, doi:10.3762/bjnano.8.199

• = 108 Å2, diffusion coefficient D = 3750 cm2/s with a thermal speed of 550 m/sec), the diffusion length Λ is calculated via the equation for the random walk . This means diffusion predominates convective flow, and the loss of monomers that will form a polymeric chain via Figure 4 has to be taken into

• mainly the surface diffusivity, and ex includes the order of the surface diffusion reaction with its diffusion coefficient [57]. Evidently the experimental data can be fitted with that model. Morphology (grain size) By diluting the chain-building vapor with argon, collisions between the monomers, which

Spin-chemistry concepts for spintronics scientists

• Konstantin L. Ivanov,
• Alexander Wagenpfahl,
• Carsten Deibel and
• Jörg Matysik

Beilstein J. Nanotechnol. 2017, 8, 1427–1445, doi:10.3762/bjnano.8.143

• D is the relative diffusion coefficient, Δr is the Laplace operator where r is the distance between the radicals. The equation for the density matrix takes the following form: where the portion of the equation in square brackets is the commutator, is the relaxation super-operator and the super

Nanoscale isoindigo-carriers: self-assembly and tunable properties

• Tatiana N. Pashirova,
• Andrei V. Bogdanov,
• Lenar I. Musin,
• Julia K. Voronina,
• Irek R. Nizameev,
• Marsil K. Kadirov,
• Vladimir F. Mironov,
• Lucia Ya. Zakharova,
• Shamil K. Latypov and
• Oleg G. Sinyashin

Beilstein J. Nanotechnol. 2017, 8, 313–324, doi:10.3762/bjnano.8.34

• -order cumulant expansion methods. The effective hydrodynamic radius (RH) was calculated according to the Einstein–Stokes equation: D = kBT/6πηRH, in which D is the diffusion coefficient, kB is the Boltzmann constant, T is the absolute temperature, and η is the viscosity. The diffusion coefficient was

Diffusion of dilute gas in arrays of randomly distributed, vertically aligned, high-aspect-ratio cylinders

• Wojciech Szmyt,
• Carlos Guerra and
• Ivo Utke

Beilstein J. Nanotechnol. 2017, 8, 64–73, doi:10.3762/bjnano.8.7

• dilute gas along arrays of randomly distributed, vertically aligned nanocylinders (nanotubes or nanowires) as opposed to gas diffusion in long pores, which is described by the well-known Knudsen theory. Analytical expressions for (i) the gas diffusion coefficient inside such arrays, (ii) the time between

• molecular regime of gas transport. It can be specifically shown that the gas diffusion coefficient inside such arrays is inversely proportional to the areal density of cylinders and their mean diameter. An example calculation of a diffusion coefficient is delivered for a system of titanium isopropoxide

• reflection from nanocylinder walls assuming the molecular regime of gas transport. The example calculation of a diffusion coefficient is delivered for a system of titanium isopropoxide molecules diffusing between vertically aligned carbon nanotubes coated with titanium dioxide, which is especially relevant

Annealing-induced recovery of indents in thin Au(Fe) bilayer films

• Anna Kosinova,
• Ruth Schwaiger,
• Leonid Klinger and
• Eugen Rabkin

Beilstein J. Nanotechnol. 2016, 7, 2088–2099, doi:10.3762/bjnano.7.199

• the gradient of the chemical potential The accumulation of atoms on the surface is proportional to the divergence of the diffusion flux. Thus, where is the Mullins coefficient. Ds and νs are the surface self-diffusion coefficient and the number of mobile atoms per unit area of the surface