5,139 research outputs found
What characteristics of smart home speakers should companies invest in? Differences between actual and potential users
The aim of the research is double. First, it aims to examine the importance of smart product features on users'' satisfaction and adopters'' purchasing intentions. Second, we want to analyse the possible quadratic effect of three features, autonomy, personality and human interaction on the two outcomes. The results show that the features of smart products that influence users'' satisfaction differ from those of adopters'' purchasing intentions. Finally, interesting managerial implications for smart product producers and dealers are offered
Importance of molecular interactions in colloidal dispersions
We review briefly the concept of colloidal dispersions, their general
properties and some of their most important applications, as well as the basic
molecular interactions that give rise to their properties in equilibrium.
Similarly, we revisit Brownian motion and hydrodynamic interactions associated
with the concept of viscosity of colloidal dispersion. It is argued that the
use of modern research tools, such as computer simulations, allows one to
predict accurately some macroscopically measurable properties by solving
relatively simple models of molecular interactions for a large number of
particles. Lastly, as a case study, we report the prediction of rheological
properties of polymer brushes using state of the art, coarse grained computer
simulations, which are in excellent agreement with experiments.Comment: 8 pages, 10 figure
H^+_2$ in a strong magnetic field described via a solvable model
We consider the hydrogen molecular ion in the presence of a strong
homogeneous magnetic field. In this regime, the effective Hamiltonian is almost
one dimensional with a potential energy which looks like a sum of two Dirac
delta functions. This model is solvable, but not close enough to our exact
Hamiltonian for relevant strenght of the magnnetic field. However we show that
the correct values of the equilibrium distance as well as the binding energy of
the ground state of the ion, can be obtained when incorporating perturbative
corrections up to second order. Finally, we show that exists for
sufficiently large magnetic fields
How 3D patient-specific instruments improve accuracy of pelvic bone tumour resection in a cadaveric study
To assess the accuracy of patient-specific instruments (PSIs) versus standard manual technique and the precision of computer-assisted planning and PSI-guided osteotomies in pelvic tumour resection. CT scans were obtained from five female cadaveric pelvises. Five osteotomies were designed using Mimics software: sacroiliac, biplanar supra-acetabular, two parallel iliopubic and ischial. For cases of the left hemipelvis, PSIs were designed to guide standard oscillating saw osteotomies and later manufactured using 3D printing. Osteotomies were performed using the standard manual technique in cases of the right hemipelvis. Post-resection CT scans were quantitatively analysed. Student's t -test and Mann-Whitney U test were used. Compared with the manual technique, PSI-guided osteotomies improved accuracy by a mean 9.6 mm (p 5 mm and 27% (n = 8) were > 10 mm. In the PSI cases, deviations were 10% (n = 3) and 0 % (n = 0), respectively. For angular deviation from pre-operative plans, we observed a mean improvement of 7.06° (p < 0.001) in pitch and 2.94° (p < 0.001) in roll, comparing PSI and the standard manual technique. In an experimental study, computer-assisted planning and PSIs improved accuracy in pelvic tumour resections, bringing osteotomy results closer to the parameters set in pre-operative planning, as compared with standard manual techniques. Cite this article : A. Sallent, M. Vicente, M. M. RevertĂ©, A. Lopez, A. RodrĂguez-Baeza, M. PĂ©rez-DomĂnguez, R. Velez. How 3D patient-specific instruments improve accuracy of pelvic bone tumour resection in a cadaveric study. Bone Joint Res 2017;6:577-583. DOI: 10.1302/2046-3758.610.BJR-2017-0094.R1
Integral field spectroscopy of nitrogen overabundant blue compact dwarf galaxies
We study the spatial distribution of the physical properties and of oxygen
and nitrogen abundances in three Blue Compact Dwarf Galaxiess (HS 0128+2832, HS
0837+4717 and Mrk 930) with a reported excess of N/O in order to investigate
the nature of this excess and, particularly, if it is associated with
Wolf-Rayet (WR) stars We have observed these BCDs by using PMAS integral field
spectroscopy in the optical spectral range (3700 - 6900 {\AA}), mapping their
physical-chemical properties, using both the direct method and appropriate
strong-line methods. We make a statistical analysis of the resulting
distributions and we compare them with the integrated properties of the
galaxies. Our results indicate that outer parts of the three galaxies are
placed on the "AGN-zone" of the [NII]/H{\alpha} vs. [OIII]/H{\beta} diagnostic
diagram most likely due to a high N/O combined with the excitation structure in
these regions. From the statistical analysis, it is assumed that a certain
property can be considered as spatially homogeneous (or uniform) if a normal
gaussian function fits its distribution in several regions of the galaxy.
Moreover, a disagreement between the integrated properties and the mean values
of the distribution usually appears when a gaussian does not fit the
corresponding distribution. We find that for Mrk 930, the uniformity is found
for all parameters, except for electron density and reddening. The rotation
curve together with the H{\alpha} map and UV images, reveal a perturbed
morphology and possible interacting processes. The N/O is found to be constant
in the three studied objects at spatial scales of the order of several kpc so
we conclude that the number of WR stars estimated from spectroscopy is not
sufficient to pollute the ISM and to produce the observed N/O excess in these
objectsComment: 17 pages, 14 figures, accepted for publication in Astronomy &
Astrophysic
HD 144432: a young triple system
We present new imaging and spectroscopic data of the young Herbig star HD
144432 A, which was known to be a binary star with a separation of 1.47 arcsec.
High-resolution NIR imaging data obtained with NACO at the VLT reveal that HD
144432 B itself is a close binary pair with a separation of 0.1 arcsec.
High-resolution optical spectra, acquired with FEROS at the 2.2m MPG/ESO
telescope in La Silla, of the primary star and its co-moving companions were
used to determine their main stellar parameters such as effective temperature,
surface gravity, radial velocity, and projected rotational velocity by fitting
synthetic spectra to the observed stellar spectra. The two companions, HD
144432 B and HD 144432 C, are identified as low-mass T Tauri stars of spectral
type K7V and M1V, respectively. From the position in the HRD the triple system
appears to be co-eval with a system age of 6+/-3 Myr.Comment: Accepted for publication in Astronomy & Astrophysics, 4 pages, 4
figure
Plasma irisin depletion under energy restriction is associated with improvements in lipid profile in metabolic syndrome patients
OBJECTIVE: A recently discovered myokine, irisin, may have an important role in energy metabolism. This study aimed to evaluate the relationship between this hormone and the lipid profile of patients with metabolic syndrome (MetS) following a hypocaloric diet. DESIGN: Ninety-three Caucasian adults (52 men/41 women) diagnosed with MetS followed an 8-week-long energy-restricted programme (-30% of the energy requirements). Anthropometric measurements, biochemical markers and plasma irisin levels were analysed before and after the nutritional intervention. RESULTS: Global plasma irisin levels were significantly reduced at the end of the study (-72.0 +/- 100.9 ng/ml, P < 0.001) accompanying the weight loss (-6.9%). The depletion of irisin significantly correlated with changes in some atherogenic-related variables: total cholesterol (B = 0.106, P = 0.018), total cholesterol/high-density lipoprotein cholesterol ratio (B = 0.002, P = 0.036), low-density lipoprotein cholesterol (B = 0.085, P = 0.037) and apolipoprotein B (B = 0.052, P = 0.002), independently of changes in body weight. CONCLUSIONS: An association between the reduction in plasma irisin levels and the depletion of important lipid metabolism biomarkers was observed in patients with MetS undergoing an energy-restricted programme
Quantum coherent control of highly multipartite continuous-variable entangled states by tailoring parametric interactions
The generation of continuous-variable multipartite entangled states is
important for several protocols of quantum information processing and
communication, such as one-way quantum computation or controlled dense coding.
In this article we theoretically show that multimode optical parametric
oscillators can produce a great variety of such states by an appropriate
control of the parametric interaction, what we accomplish by tailoring either
the spatio-temporal shape of the pump, or the geometry of the nonlinear medium.
Specific examples involving currently available optical parametric oscillators
are given, hence showing that our ideas are within reach of present technology.Comment: 14 pages, 5 figure
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