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Search for "barrier" in Full Text gives 520 result(s) in Beilstein Journal of Nanotechnology. Showing first 200.
Atmospheric water harvesting using functionalized carbon nanocones
Beilstein J. Nanotechnol. 2023, 14, 1–10, doi:10.3762/bjnano.14.1
- [34]. Also, it is the nanocone that achieves the highest values of water flux compared with the other apex angles. It also presents a lower energy barrier when compared with carbon nanotubes [39]. The smaller side of the nanocone ends in a hydrophilic surface, which has the same structure as the
Induced electric conductivity in organic polymers
Beilstein J. Nanotechnol. 2022, 13, 1551–1557, doi:10.3762/bjnano.13.128
- is significantly different. In particular, as the voltage increases, there is the tendency for the current flowing through the heterostructure to saturate. Previously [2], it was found that at high temperatures, the mechanism of overcoming the barrier at the metal/polymer contact is satisfactorily
- following values n0 = 1021−1023 m−3, μ = 10−15 to 10−17 m2/Vs. The analysis of the I–V characteristics within the framework of Schottky barrier formation makes it possible to estimate the height of potential barriers at the metal/polymer interfaces utilizing the Richardson expression [18]: where T is the
- -called current at zero voltage. In addition, it is necessary to take into account the non-ideality coefficient of the barrier. We chose the value of the latter from previous measurements. As the result, the value of the potential barrier calculated using Equation 3 is equal to 0.7. As expected, the
In search of cytotoxic selectivity on cancer cells with biogenically synthesized Ag/AgCl nanoparticles
Beilstein J. Nanotechnol. 2022, 13, 1505–1519, doi:10.3762/bjnano.13.124
- consistent with Reddy et al. [41], who reported that phytochemicals capped on nanoparticles support thermal stability upon temperature changes. The second situation is the thermal barrier that Ag/AgCl nanoparticles themselves, based on their intrinsic characteristics, provide to the system. This last
Density of states in the presence of spin-dependent scattering in SF bilayers: a numerical and analytical approach
Beilstein J. Nanotechnol. 2022, 13, 1418–1431, doi:10.3762/bjnano.13.117
- DOS for different values of the exchange field h and the barrier transparency γB. All the scattering is assumed to be absent for simplicity αm = αx = αso = 0 in this subsection. In Figure 2, we observe the influence of an increasing exchange field h on the DOS structure calculated for γB = 5. In
- previously published findings. Geometry of the SF bilayer. We consider the SF interface to be a tunnel barrier. Here, γB is the interface transparency parameter. The evolution of the DOS plotted for increasing values of the exchange field h. Here, γB = 5, df = 0.5ξf. In plot (a), the gray dotted line
Recent trends in Bi-based nanomaterials: challenges, fabrication, enhancement techniques, and environmental applications
Beilstein J. Nanotechnol. 2022, 13, 1316–1336, doi:10.3762/bjnano.13.109
- vacancies in monolayered Bi2WO6 nanosheets with a thickness of 1.0 nm have recently been shown [82]. The Bi defects were shown to promote the adsorption and activation of reactant molecules, which reduced the energy barrier even more. The photocatalytic performance corroborated this. The presence of
A super-oscillatory step-zoom metalens for visible light
Beilstein J. Nanotechnol. 2022, 13, 1220–1227, doi:10.3762/bjnano.13.101
- -high-density data storage. Thus, overcoming the barrier of diffraction limit and achieve super-resolution optical imaging has become a hot topic in the research field of optics. In recent years, a variety of super-resolution optical microscopy techniques have been developed. For instance, stimulated
Microneedle-based ocular drug delivery systems – recent advances and challenges
Beilstein J. Nanotechnol. 2022, 13, 1167–1184, doi:10.3762/bjnano.13.98
- closely packed cells equipped with tight junctions. Its thickness is approximately 50 μm [40], and it plays an important protective role. The posterior segment of the eye contains sclera, choroid, Bruch’s membrane, and blood–retinal barrier, which further prevent drug permeation. The thickness of the
- sclera, a membrane composed of randomly scattered collagen fibers, ranges from 0.5 to 1 mm, depending on the region of occurrence [41]. While the sclera is another barrier preventing drug permeation, the choroid is responsible for drug elimination. The blood–retinal barrier is connected to the retinal
Design of a biomimetic, small-scale artificial leaf surface for the study of environmental interactions
Beilstein J. Nanotechnol. 2022, 13, 944–957, doi:10.3762/bjnano.13.83
- with its superimposed epicuticular waxes represents the barrier of all aboveground parts of higher plant primary tissues. Epicuticular waxes have multiple effects on the interaction of plants with their living and non-living environment, whereby their shape, dimension, arrangement, and chemical
- functions (Figure 1). Among other things, it protects against herbivores and pathogens, provides mechanical stability, reflects harmful UV radiation [2][3][4][5][6], and mainly protects the plant from desiccation [7][8]. The cuticular waxes contribute significantly to this barrier function. Plant waxes
Bioselectivity of silk protein-based materials and their bio-inspired applications
Beilstein J. Nanotechnol. 2022, 13, 902–921, doi:10.3762/bjnano.13.81
- polymer chains against protein molecules increases, while a tightly bound water layer creates a physical and energetic barrier and renders interactions with approaching proteins or bacteria thermodynamically unfavorable [50]. The concept of steric repulsion based on a hydration layer through hydrogen
Efficiency of electron cooling in cold-electron bolometers with traps
Beilstein J. Nanotechnol. 2022, 13, 896–901, doi:10.3762/bjnano.13.80
- currents may have the same nature, since they both exist due to SN-pinholes in a tunnel barrier. Actually, it is an open question whether these currents are two different components or rather the same current but calculated with different approaches. Here we work with these two currents independently. For
- tunneling barrier of the NIS junctions and smaller single-particle and double-particle components of the current. For sample C, the normal resistance per one NIS junction is 1.3 kΩ, and for sample OL-G7nn this resistance is 6.4 kΩ. These differences can be seen in the electron temperature graphs: For the
- of the tunnel barrier (larger resistance) and the corresponding decrease of the single-particle current, which withdraws hot electrons from the absorber. However, due to the lower Andreev heating current, which, when flowing through the normal metal absorber, leads to residual heating and, thus
Hierachical epicuticular wax coverage on leaves of Deschampsia antarctica as a possible adaptation to severe environmental conditions
Beilstein J. Nanotechnol. 2022, 13, 807–816, doi:10.3762/bjnano.13.71
- Bay) to 400 mm per year (South Shetland Islands) [26]. In general, a continuous epicuticular wax layer is known to serve as an transport barrier limiting the uncontrolled water loss in plants [38][41]. The presence of a thick wax coverage has been considered as one of typical xeromorphic features (i.e
Experimental and theoretical study of field-dependent spin splitting at ferromagnetic insulator–superconductor interfaces
Beilstein J. Nanotechnol. 2022, 13, 682–688, doi:10.3762/bjnano.13.60
- , indicating a defect-free tunnel barrier. Spin splitting of the density of states is clearly visible. The observed splitting greatly exceeds the expected splitting due to the Zeeman energy εZ = μBB (which is about 35 μeV at B = 0.6 T). The solid lines in Figure 5a are fits with our model. We have included
- with help of the top normal contact (N), which is separated by an insulating barrier (I). (b) Circuit diagram to represent the FI–S bilayer in the quantum circuit theory. The superconductor is represented by the node, the Δ-source term, the εTh-leakage term, and its normal-state conductance G. The
Fabrication and testing of polymer microneedles for transdermal drug delivery
Beilstein J. Nanotechnol. 2022, 13, 629–640, doi:10.3762/bjnano.13.55
- the MN before skin rupture. Several methods are used to estimate these critical loads and their associated stresses, including theoretical analysis, experimental investigations, and FEA simulations [21]. For example, due to the skin’s SC barrier, the normal (vertical) insertion of MN patches on the
Approaching microwave photon sensitivity with Al Josephson junctions
Beilstein J. Nanotechnol. 2022, 13, 582–589, doi:10.3762/bjnano.13.50
- rate. Therefore, its value is underestimated in dc measurements. The upper limit is given by the BCS expression 1.75kTc/(eRN) [29], which depends on the critical temperature of the electrodes and the normal resistance of the tunnel barrier only. This maximum possible critical current is difficult to
- damping values [48][49]: The used notations are the following: i = Ibias/Ic is the dimensionless bias current with the bias current Ibias and the critical current Ic, is the potential barrier height, γ = IT/Ic is the noise intensity, and IT = 2ekT/ℏ is the fluctuational current which can be calculated as
- , the probability of switching due to the absorption of 3 photons is 0.002. In Figure 2b the barrier height is compared with the energy of one photon. The potential profile is calculated for the critical current of 8.586 μA. Photon frequency and energy are, respectively, 10 GHz and 6.8 × 10−24 J. The
Ciprofloxacin-loaded dissolving polymeric microneedles as a potential therapeutic for the treatment of S. aureus skin infections
Beilstein J. Nanotechnol. 2022, 13, 517–527, doi:10.3762/bjnano.13.43
- , 19392, Jordan 10.3762/bjnano.13.43 Abstract Microneedles have been widely studied for many topical and transdermal therapeutics due to their ability to painlessly puncture the skin, thereby bypassing the stratum corneum, the main skin barrier. In this study, ciprofloxacin (CIP) was loaded into
- STSI [17]. Therefore, a proper delivery system that can evade the barrier properties of the skin is essential to be effective in the treatment of cellulitis and other skin infections. In this work, the potential of dissolving polymeric microneedles loaded with ciprofloxacin for the treatment of S
- Parafilm and an agarose-based skin model. Parafilm has been utilized to test the insertion properties of polymeric microneedles [20]. Parafilm-M is mainly composed of paraffin waxes and polyalkene (polyolefin) [21] and, thus, presumably similar in hydrophobicity to the stratum corneum, the main barrier of
Design and characterization of polymeric microneedles containing extracts of Brazilian green propolis
Beilstein J. Nanotechnol. 2022, 13, 503–516, doi:10.3762/bjnano.13.42
- Abstract Microneedles (MNs) are a means to break the protective skin barrier in a minimally invasive way. By creating temporary micropores, they make biologically active agents available in the skin layers. Propolis (PRP) is a gum resin with a complex chemical composition, produced by bees Apis mellifera L
- gastrointestinal one. Despite the great therapeutic potential, the use of this pathway is limited by the low permeation of molecules through the stratum corneum, the outermost layer of the skin, which works as a barrier, blocking the transport of drugs through the subcutaneous tissue. To overcome this difficulty
Ethosomal (−)-epigallocatechin-3-gallate as a novel approach to enhance antioxidant, anti-collagenase and anti-elastase effects
Beilstein J. Nanotechnol. 2022, 13, 491–502, doi:10.3762/bjnano.13.41
- many drugs. The stratum corneum in the epidermis, which is the top layer of the skin consisting of three layers, acts as an important barrier against penetration into the skin [9][16]. To overcome penetration limitations, various techniques such as penetration enhancers, phonophoresis, electroporation
Zinc oxide nanostructures for fluorescence and Raman signal enhancement: a review
Beilstein J. Nanotechnol. 2022, 13, 472–490, doi:10.3762/bjnano.13.40
- occurred from Ag and Au NPs to ZnO NRs. The 3D hybrid structures improve the surface-to-volume ratio, yielding a higher SERS activity. Moreover, the formation of “hotspots” and the Shottky barrier at the interface between ZnO NRs and the decorated Au NPs increases the SERS activity. Furthermore, limits of
Alcohol-perturbed self-assembly of the tobacco mosaic virus coat protein
Beilstein J. Nanotechnol. 2022, 13, 355–362, doi:10.3762/bjnano.13.30
- rods. This could be the result of increased hydrophobic interaction strength, as determined by Lee and co-workers [33]. If disks interact with each other too strongly in the initial non-helical conformation, the energy barrier to rearrange into a helical conformation may become prohibitive. Potential
Controllable two- and three-state magnetization switching in single-layer epitaxial Pd1−xFex films and an epitaxial Pd0.92Fe0.08/Ag/Pd0.96Fe0.04 heterostructure
Beilstein J. Nanotechnol. 2022, 13, 334–343, doi:10.3762/bjnano.13.28
- reversal, since the volume of the material is divided into two fractions that rotate their moments in opposite directions. In addition, at the field strengths of the second jump in magnetization, the height of the barrier for the coherent rotation also becomes insignificant. Therefore, in this range of
A broadband detector based on series YBCO grain boundary Josephson junctions
Beilstein J. Nanotechnol. 2022, 13, 325–333, doi:10.3762/bjnano.13.27
- , respectively [36][37]. For a Josephson junction having a non-hysteretic IVC, the output voltage spectrum at a fixed bias current is defined as [38]: where Rd is the differential resistance; and depend on the nature of the junction barrier. For the considered structures, SI = 10−12 was chosen as a typical
The effect of metal surface nanomorphology on the output performance of a TENG
Beilstein J. Nanotechnol. 2022, 13, 298–312, doi:10.3762/bjnano.13.25
- barrier of electron transfer, thus, enabling electron flow from insulator to metal (vice versa) or from an insulator to another insulator. TENGs are miniaturized and portable. They generate current by collecting tiny amounts of energy and supply power for microelectronic devices and sensors. Wind energy
Relationship between corrosion and nanoscale friction on a metallic glass
Beilstein J. Nanotechnol. 2022, 13, 236–244, doi:10.3762/bjnano.13.18
- films form on most metal surfaces and act as a barrier to the corrosive environment, thus impeding further corrosion. The corrosion properties of MGs, for example, the ability to passivate and to remain in the passive state in corrosive aqueous solutions, have been addressed in many studies using
- electrochemical methods, often combined with surface analytical techniques [13][14][15]. Wang et al. [13] reported that the passive oxide films are grown as a double layer structure on MGs with a corrosion product layer underlying an inner barrier layer in NaCl and Na2SO4 solutions. Since most metals and alloys
Impact of device design on the electronic and optoelectronic properties of integrated Ru-terpyridine complexes
Beilstein J. Nanotechnol. 2022, 13, 219–229, doi:10.3762/bjnano.13.16
- , verified by temperature-dependent conductance measurements. Next we discuss the impact of this finding on the electrical switching ability of few-Ru(MPTP)2–AuNP compared to single-Ru(MPTP)2–AuNP devices. The recently reported ideal single-AuNP devices are described as double-barrier tunnel junctions [15
Engineered titania nanomaterials in advanced clinical applications
Beilstein J. Nanotechnol. 2022, 13, 201–218, doi:10.3762/bjnano.13.15
- small size of nanomaterials enables them to permeate through biological barriers in the body, such as the blood–brain barrier, the pulmonary system, and through the tight junction of endothelial cells of the skin. The main goal of loading drugs on nanomaterials is the delivery to specific target cells
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