647 research outputs found
Ultimate limits to inertial mass sensing based upon nanoelectromechanical systems
Nanomechanical resonators can now be realized that achieve fundamental resonance frequencies exceeding 1 GHz, with quality factors (Q) in the range 10^3<=Q<=10^5. The minuscule active masses of these devices, in conjunction with their high Qs, translate into unprecedented inertial mass sensitivities. This makes them natural candidates for a variety of mass sensing applications. Here we evaluate the ultimate mass sensitivity limits for nanomechanical resonators operating in vacuo that are imposed by a number of fundamental physical noise processes. Our analyses indicate that nanomechanical resonators offer immense potential for mass sensing—ultimately with resolution at the level of individual molecules
Do Blue Flag promotions influence tourists’ willingness to pay a price premium for coastal destinations?
The Blue Flag is a popular eco-label in tourism. This study aims at examining the effectiveness of Blue Flag promotion on tourists' willingness to pay a price premium to coastal destinations via two online experiments. Study 1 shows (n = 152) that the Blue Flag stimulates higher willingness to pay a price premium for coastal destinations directly as well as indirectly through self-congruity and destination brand identification. Study 2 (n = 160) used a new sample to enhance external validity and generalizability of the Study 1 findings. Study 2 shows that destination brand quality and destination brand identification serially mediate the effect of Blue Flag promotions on the tourist's willingness to pay a price premium. The findings suggest that destination managers should deploy the Blue Flag Logo in destination promotions to enhance self-congruence, destination brand identification, perceived destination quality, and the tourist's willingness to pay a price premium
Balanced electronic detection of displacement in nanoelectromechanical systems
We describe a broadband radio frequency balanced bridge technique for electronic detection of displacement in nanoelectromechanical systems (NEMS). With its two-port actuation-detection configuration, this approach generates a background-nulled electromotive force in a dc magnetic field that is proportional to the displacement of the NEMS resonator. We demonstrate the effectiveness of the technique by detecting small impedance changes originating from NEMS electromechanical resonances that are accompanied by large static background impedances at very high frequencies. This technique allows the study of important experimental systems such as doped semiconductor NEMS and may provide benefits to other high frequency displacement transduction circuits
The brand likeability scale: an exploratory study of likeability in firm-level brands
We develop a new measurement scale to assess consumers’ brand likeability in firm-level brands. We present brand likeability as a multi-dimensional construct. In the context of service experience purchases, we find that increased likeability in brands results in (1) greater amount of positive association, (2) increased interaction interest, (3) more personified quality, and (4) increased brand contentment. The four-dimensional multiple-item scale demonstrates good psychometric properties, showing strong evidence of reliability as well as convergent, discriminant, and nomological validity. Our findings reveal that brand likeability is positively associated with satisfaction and positive word-of-mouth. The scale extends existing branding research, providing brand managers with a metric so that likeability can be managed strategically. It addresses the need for firms to act more likeable in an interaction-dominated economy. Focusing on likeability acts as a differentiator and encourages likeable brand personality traits. We present theoretical implications and future research directions on the holistic brand likeability concept
Intrinsic dissipation in high-frequency micromechanical resonators
We report measurements of intrinsic dissipation in micron-sized suspended resonators machined from single crystals of galium arsenide and silicon. In these experiments on high-frequency micromechanical resonators, designed to understand intrinsic mechanisms of dissipation, we explore dependence of dissipation on temperature, magnetic field, frequency, and size. In contrast to most of the previous measurements of acoustic attenuation in crystalline and amorphous structures in this frequency range, ours is a resonant measurement; dissipation is measured at the natural frequencies of structural resonance, or modes of the structure associated with flexural and torsional motion. In all our samples we find a weakly temperature dependent dissipation at low temperatures. We compare and contrast our data to various probable mechanisms, including thermoelasticity, clamping, anharmonic mode-coupling, surface anisotropy and defect motion, both in bulk and on surface. The observed parametric dependencies indicate that the internal defect motion is the dominant mechanism of intrinsic dissipation in our samples
Monocrystalline silicon carbide nanoelectromechanical systems
SiC is an extremely promising material for nanoelectromechanical systems given its large Young's modulus and robust surface properties. We have patterned nanometer scale electromechanical resonators from single-crystal 3C-SiC layers grown epitaxially upon Si substrates. A surface nanomachining process is described that involves electron beam lithography followed by dry anisotropic and selective electron cyclotron resonance plasma etching steps. Measurements on a representative family of the resulting devices demonstrate that, for a given geometry, nanometer-scale SiC resonators are capable of yielding substantially higher frequencies than GaAs and Si resonators
Early stage morphology of quench condensed Ag, Pb and Pb/Ag hybrid films
Scanning Tunneling Microscopy (STM) has been used to study the morphology of
Ag, Pb and Pb/Ag bilayer films fabricated by quench condensation of the
elements onto cold (T=77K), inert and atomically flat Highly Oriented Pyrolytic
Graphite (HOPG) substrates. All films are thinner than 10 nm and show a
granular structure that is consistent with earlier studies of QC films. The
average lateral diameter, , of the Ag grains, however, depends on
whether the Ag is deposited directly on HOPG ( = 13 nm) or on a Pb
film consisting of a single layer of Pb grains ( = 26.8 nm). In
addition, the critical thickness for electrical conduction () of Pb/Ag
films on inert glass substrates is substantially larger than for pure Ag films.
These results are evidence that the structure of the underlying substrate
exerts an influence on the size of the grains in QC films. We propose a
qualitative explanation for this previously unencountered phenomenon.Comment: 11 pages, 3 figures and one tabl
Destination Image and Destination Personality: An Application of Branding Theories to Tourism Places
This study investigates the relationship between destination image and destination personality. While brand image and brand personality studies is well documented in the generic marketing literature, application of branding theories to places, in particular to tourism destinations, is relatively new. Using tourism destinations as a setting, this study contribute to the debate on the brand image – brand personality relationship. Results indicate that destination image and destination personality are related concepts. Canonical correlation analysis reveals that the emotional component of destination image captures the majority of variance on destination personality dimensions
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