Behavior or culture? Investigating the use of cryptocurrencies for electronic commerce across the USA and China

Purpose This paper claims to identify the behavioral and cultural features that push to use, or not, cryptocurrencies for electronic commerce. Indeed, despite the use of cryptocurrencies for electronic commerce spreading worldwide at a fast and growing pace, there are supporters and detractors among their users. The analysis of what distinguish these two groups of users is fundamental for understanding their different intention to use cryptocurrencies for electronic commerce. Design/methodology/approach A survey has been administered to 2,532 cryptocurrencies’ users across the USA and China, collecting data on their behavioral predispositions and cultural features. Results were then analyzed through structured equation modeling. Findings Results showed that while attitude, subjective norms, perceived behavioral control and herding behavior have a positive impact on the intention to use cryptocurrencies for electronic commerce, financial literacy has no influence. Cultural dimensions amplified or reduced the discovered relationships and caused different effects: positive for the USA and negative for China when considering illegal attitude and perceived risk. Originality/value Theory of planned behavior, financial behavior and cultural factors can, all together, represent a useful framework for envisioning the behavior of users in adopting cryptocurrencies for electronic commerce purposes through a test of all its elements. To the best of the authors’ knowledge, this is the first study considering behavior and cultural variables on the intention to use cryptocurrencies for electronic commerce as well as being the largest carried out, in terms of sample, on the cryptocurrency topic

Incommensurate magnetic order in the alpha-Fe(Te,Se) superconductor systems

Magnetic spin fluctuations is one candidate to produce the bosonic modes that mediate the superconductivity in the ferrous superconductors. Up until now, all of the LaOFeAs and BaFe2As2 structure types have simple commensurate magnetic ground states, as result of nesting Fermi surfaces. This type of spin-density-wave (SDW) magnetic order is known to be vulnerable to shifts in the Fermi surface when electronic densities are altered at the superconducting compositions. Superconductivity has more recently been discovered in alpha-Fe(Te,Se), whose electronically active antifluorite planes are isostructural to the FeAs layers found in the previous ferrous superconductors and share with them the same quasi-two-dimensional electronic structure. Here we report neutron scattering studies that reveal a unique complex incommensurate antiferromagnetic order in the parent compound alpha-FeTe. When the long-range magnetic order is suppressed by the isovalent substitution of Te with Se, short-range correlations survive in the superconducting phase.Comment: 27 pages, 7 figures, 1 tabl

Charge carrier localization induced by excess Fe in the Fe1+y(Te,Se) superconductor system

We have investigated the effect of Fe nonstoichiometry on properties of the Fe1+y(Te, Se) superconductor system by means of resistivity, Hall coefficient, magnetic susceptibility, and specific heat measurements. We find that the excess Fe at interstitial sites of the (Te, Se) layers not only suppresses superconductivity, but also results in a weakly localized electronic state. We argue that these effects originate from the magnetic coupling between the excess Fe and the adjacent Fe square planar sheets, which favors a short-range magnetic order.Comment: 15 pages, 6 figures accepted for publication in PR

Flexural-strengthening efficiency of cfrp sheets for unbonded post-tensioned concrete T-beams

There has been a limited number of studies about the flexural behavior of unbonded post-tensioned concrete (UPC) beams strengthened with carbon fibre reinforced polymer (CFRP) and these studies have not systematically examined the effect of CFRP sheets on the tendon strain as well as the strengthening efficiency. Moreover, current design guides for the FRP strengthening techniques have not provided any design procedure for UPC structures. This study, thus, investigates the influence of CFRP sheet ratio on the flexural behavior of CFRP-strengthened UPC T-beams and quantifies its effect upon tendon behavior in this kind of UPC beams. The testing program consisted of nine large-scale UPC T-beams strengthened by different layers of CFRP sheets with or without CFRP U-wrapped anchors. The experimental results have shown that the use of CFRP sheets and CFRP U-wrapped anchors significantly affected the tendon strain. The FRP reinforcement ratio governed the flexural capacity, the crack width, the mid-span displacement, and the ductility of the beams in which the strengthening efficiency reduces with the increased number of CFRP layers. The configuration of the CFRP U-wrapped anchors affected the strain of the CFRP sheets, the failure mode and thus the beam behavior. In addition, semi-empirical equations were proposed to estimate the actual strain of unbonded tendons in which the effect of the CFRP sheets and CFRP U-wrapped anchors have been taken into consideration. The proposed equations, which are simple to use, yield reliable predictions with a small variation

Natural stimulus responsive scaffolds/cells for bone tissue engineering : influence of lysozyme upon scaffold degradation and osteogenic differentiation of cultured marrow stromal cells induced by CaP coatings

This work proposes the use of nonporous, smart, and stimulus responsive chitosan-based scaffolds for bone tissue engineering applications. The overall vision is to use biodegradable scaffolds based on chitosan and starch that present properties that will be regulated by bone regeneration, with the capability of gradual in situ pore formation. Biomimetic calcium phosphate (CaP) coatings were used as a strategy to incorporate lysozyme at the surface of chitosan-based materials with the main objective of controlling and tailoring their degradation profile as a function of immersion time. To confirm the concept, degradation tests with a lysozyme concentration similar to that incorporated into CaP chitosan-based scaffolds were used to study the degradation of the scaffolds and the formation of pores as a function of immersion time. Degradation studies with lysozyme (1.5 g=L) showed the formation of pores, indicating an increase of porosity (*5–55% up to 21 days) resulting in porous threedimensional structures with interconnected pores. Additional studies investigated the influence of a CaP biomimetic coating on osteogenic differentiation of rat marrow stromal cells (MSCs) and showed enhanced differentiation of rat MSCs seeded on the CaP-coated chitosan-based scaffolds with lysozyme incorporated. At all culture times, CaP-coated chitosan-based scaffolds with incorporated lysozyme demonstrated greater osteogenic differentiation of MSCs, bone matrix production, and mineralization as demonstrated by calcium deposition measurements, compared with controls (uncoated scaffolds). The ability of these CaP-coated chitosan-based scaffolds with incorporated lysozyme to create an interconnected pore network in situ coupled with the demonstrated positive effect of these scaffolds upon osteogenic differentiation of MSCs and mineralized matrix production illustrates the strong potential of these scaffolds for application in bone tissue engineering strategies.The authors would like to acknowledge Dr. Serena Danti. This work was supported by the European NoE EX-PERTISSUES (NMP3-CT-2004-500283), the European STREP HIPPOCRATES (NMP3-CT-2003-505758), and the Portuguese Foundation for Science and Technology (FCT) through POCTI and/or FEDER programs. This work was also supported by a grant from the National Institutes of Health (NIH; R01 DE15164) (A. G. M.) and a Bioengineering Research Partnership with the Baylor College of Medicine through the National Institute of Biomedical Imaging and Bioengineering (NIH Grant 5 R01 EB005173-02). F. K. K. is supported by a training fellowship from the Keck Center Nanobiology Training Program of the Gulf Coast Consortia (NIH Grant 5 T90 DK070121-03)

"Smart'' and stimulus responsive chitosan-based scaffolds/cells for bone tissue engineering: Influence of lysozyme upon scaffold degradation and osteogenic differentiation of cultured marrow stromal cells induced by cap coatings

[Excerpt] The present study reports the use of non-porous, ‘‘smart’’ and stimulus responsive chitosan-based scaffolds with the capability of gradual in situ pore formation for bone tissue engineering applications. Biomimetic calcium phosphate (CaP) coatings were used as a strategy to incorporate lysozyme at the surface of chitosan based materials the main objective of controlling their degradation profile as a function of immersion time. In order to confirm the concept, degradation tests with concentration similar to those incorporated into CaP chitosan-based scaffolds were used to study the degradation of the scaffolds and the formation of pores as function of immersion time. Degradation studies with lysozyme (1.5 g/L) showed the formation of pores, indicating an increase of porosity (~5% - 55% up to 21 days) resulting in porous 3-D structures with interconnected pores. […]info:eu-repo/semantics/publishedVersio

Spin-dependent transport in a Luttinger liquid

We develop a detailed theory for spin transport in a one-dimensional quantum wire described by Luttinger liquid theory. A hydrodynamic description for the quantum wire is supplemented by boundary conditions taking into account the exchange coupling between the magnetization of ferromagnetic reservoirs and the boundary magnetization in the wire. Spin-charge separation is shown to imply drastic and qualitative consequences for spin-dependent transport. In particular, the spin accumulation effect is quenched except for fine-tuned parameter regimes. We propose several feasible setups involving an external magnetic field to detect this phenomenon in transport experiments on single-wall carbon nanotubes. In addition, electron-electron backscattering processes, which do not have an important effect on thermodynamic properties or charge transport, are shown to modify spin-dependent transport through long quantum wires in a crucial way.Comment: 23 pages, 4 figure