658 research outputs found
SUBARU and e-Merlin observations of NGC3718. Diaries of an SMBH recoil?
NGC3718 is a LINER galaxy, lying at a distance of about
Mpc away from earth and its similarities with NGC5128 often award it the name
"northern Centaurus A". We use high angular resolution ( mas) e-Merlin
radio and SUBARU NIR ( mas) data, to take a detailed view of the
processes taking place in its central region. In order to preserve some
objectivity in our interpretation, we combine our results with literature
values and findings from previous studies. Our NIR maps suggest, on one hand,
that towards the stellar bulge there are no large scale absorption phenomena
caused by the apparent dust lane and, on the other, that there is a significant
(local) contribution from hot ( K) dust to the nuclear NIR emission.
The position where this takes place appears to be closer to the offset compact
radio emission from our e-Merlin cm map, lying offset by pc from
the center of the underlying stellar bulge. The shape of the radio map suggests
the presence of one (or possibly two, forming an X-shape) bipolar structure(s)
() arcsec across, which combined with the balance between the
gas and the stellar velocity dispersions and the presence of hard X-ray
emission, point towards effects expected by AGN feedback. We also argue that
NGC3718 has a "core" in its surface brightness profile, despite the fact that
it is a gas-rich galaxy and we discuss its mixed photometric and spectroscopic
characteristics. The latter combined with the observed spatial and radio
offsets, the relative redshift between the broad and the narrow
line, the limited star formation activity and AGN
feedback, strongly imply the existence of an SMBH recoil. Finally, we discuss a
possible interpretation, that could naturally incorporate all these findings
into one physically consistent picture.Comment: 18 pages, 18 figures, 3 tables, accepted for publications in A&
Structureâproperty relationships of âsafeâ aromatic oil based passenger car tire tread rubber compounds
In this study, the effect of Treated Distillate Aromatic Extract (TDAE) was investigated in medium styrene/high vinyl solution styrene butadiene rubber (S-SBR) and high cis-polybutadiene rubber (BR). Three properties were evaluated: (i) molecular structure (polarity/aromaticity), (ii) molecular weight and (iii) chemical reactivity of the TDAE oil. The fore-mentioned properties of the oil allow the prediction of its behavior in a rubber compound. It was known from literature that the addition of oil causes a shift in the glass transition temperature (Tg) of the compound [2]. Therefore, the study was focused on the variation in the α-relaxation process or Tg of a rubber compound upon addition of TDAE. The conventional techniques for determination of Tg such as Differential Scanning Calorimetry (DSC) and Dynamic Mechanical Analysis (DMA) as well as more sophisticated relaxation studies using Broadband Dielectric Spectroscopy (BDS) were used to characterize the TDAE-extended S-SBR and BR compounds. Theoretical prediction of the Tg of TDAE-extended compounds was obtained based on the Fox equation for miscible mixtures. Ultimately, the theoretical predictions were correlated with experimental findings
Evaluation of Three New Strategies to Fight Obesity in Families
Aims. To evaluate 3 strategies to reduce weight in obese families. Research design and methods. 142 obese parents and 119 obese children kept a fat-calorie restriction diet. On top of this diet, the families were randomized in a three-factorial design to one or more of three weight-loss strategies: (1) an additional diet preferring carbohydrates having a low glycemic index (dual diet), (2) financial incentive, and (3) telemonitoring of weight and physical activity. Results. All children improved their BMI-SDS by 0.18 ± 0.25 (P < .001) independently of the weight-loss strategy. In parents, relative losses of weight (kg) were â6.4% versus â4.0% for dual diet versus calorie restriction (P = .029), â6.9% versus â3.4% for with or without financial incentive (P = .002), and â8.0% versus â4.8% for with or without telemonitoring (P = .033). The weight loss after financial incentive plus dual diet plus telemonitoring was â14.4%. Conclusions. All strategies were effective in adults, in particular when combined. Children improved their BMI-SDS regardless of the strategy
Effect of Aromatic Oil on Phase Dynamics of S-SBR/BR Blends fro Passenger Car Tire Treads
Even though S-SBR/BR blends are commonly used for passenger car tire treads, little is known about the phase dynamics arising from the local morphological heterogeneities. The present study aims at developing the understanding of: (i) the influence of aromatic oil on the dynamics of the individual phases in S-SBR/BR (50/50) blend, and (ii) the partition of the aromatic oil in either phase.\ud
S-SBR/BR (50/50) blends with varying concentrations of aromatic oil (0/10/20 phr) were studied. Conventional techniques for the determination of Tg (glass transition temperature or α-relaxation process), such as Differential Scanning Calorimetry (DSC) and Dynamic Mechanical Analysis (DMA) were of limited use for fulfilling the goal of the present study. Therefore, Broadband Dielectric Spectroscopy (BDS), a more sensitive technique to study the α-relaxation process was employed. It was possible to de-convolute the dielectric loss (Δ") peak of the vulcanized blends into two super-positioned relaxation processes, α' and α (in increasing order of frequency), which were attributed to the S-SBR and BR phases, respectively. The distinct effective Tgâs (Tgeff) of the S-SBR and BR phases varied with the amount of aromatic oil added. Tgeff of the BR phase was close to the Tg of virgin BR, whereas Tgeff of the S-SBR phase was close to the blend average Tg. This is in accordance with the model for phase dynamics of miscible blends by Lodge and McLeish (2000). With this a deeper insight into the dynamic heterogeneity of traditional S-SBR/BR (50/50) blends is obtained
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