835 research outputs found
Validation and Verification of Steady Resistance KCS Simulations with Sinkage and Trim using Embedded Free Surface Method
Classical Cepheids, what else?
We present new and independent estimates of the distances to the Magellanic
Clouds (MCs) using near-infrared (NIR) and optical--NIR period--Wesenheit (PW)
relations. The slopes of the PW relations are, within the dispersion, linear
over the entire period range and independent of metal content. The absolute
zero points were fixed using Galactic Cepheids with distances based on the
infrared surface-brightness method. The true distance modulus we found for the
Large Magellanic Cloud--- mag---and the
Small Magellanic Cloud--- mag---agree quite
well with similar distance determinations based on robust distance indicators.
We also briefly discuss the evolutionary and pulsation properties of MC
Cepheids
Simulacija udarnih valnih opterećenja u OpenFOAM-u
Tema ovog rada je primjena numeričkih proračuna udarnih valnih opterećenja na nepomične konstrukcije pomorske tehnike. Korišten je programski paket Naval Hydro Pack u programu OpenFOAM. Korišten je model dvofaznog strujanja sa slobodnom površinom pomoću “Volume of Fluid” metode i “Level Set” metode. Jednadžbe su diskretizirane metodom kontrolnih volumena. Ukratko je prikazan način modeliranja valova pomoću relaksacijskih zona. Proveden je proračun opterećenja kvadratnog stupa uslijed udarnog vodenog vala te su rezultati uspoređeni s eksperimentalnim vrijednostima. Prikazan je način generiranja ekstremnog vala (engl. „freak wave“) pomoću fokusiranja valnih komponenti standardnog spektra energije valova. Provedena je simulacija ekstremnog vala te su prikazani rezultati proračuna
On the distance of the Magellanic Clouds using Cepheid NIR and optical-NIR Period Wesenheit Relations
We present the largest near-infrared (NIR) data sets, , ever collected
for classical Cepheids in the Magellanic Clouds (MCs). We selected fundamental
(FU) and first overtone (FO) pulsators, and found 4150 (2571 FU, 1579 FO)
Cepheids for Small Magellanic Cloud (SMC) and 3042 (1840 FU, 1202 FO) for Large
Magellanic Cloud (LMC). Current sample is 2--3 times larger than any sample
used in previous investigations with NIR photometry. We also discuss optical
photometry from OGLE-III. NIR and optical--NIR Period-Wesenheit (PW)
relations are linear over the entire period range () and their slopes are, within the intrinsic dispersions, common between the
MCs. These are consistent with recent results from pulsation models and
observations suggesting that the PW relations are minimally affected by the
metal content. The new FU and FO PW relations were calibrated using a sample of
Galactic Cepheids with distances based on trigonometric parallaxes and Cepheid
pulsation models. By using FU Cepheids we found a true distance moduli of
mag (LMC) and
mag (SMC). These estimates
are the weighted mean over ten PW relations and the systematic errors account
for uncertainties in the zero-point and in the reddening law. We found similar
distances using FO Cepheids
( mag [LMC] and
mag [SMC]). These new MC
distances lead to the relative distance, mag (FU, ) and mag (FO, ),which agrees quite
well with previous estimates based on robust distance indicators.Comment: 17 pages, 7 figure
Primjena Naval Hydro Paketa za Proračun Valnih Opterećenja
Ovaj rad prikazuje mogućnosti primjene programskog paketa NavalHydro u programu OpenFOAM na probleme određivanja valnih opterećenja u brodogradnji. Diskretizacija Navier-Stokesovih jednadžbi se provodi metodom kontrolnih volumena, dok se za praćenje slobodne površine koristi „Volume of Fluid“ metoda. Paket NavalHydro prilagođen je provođenju proračuna gdje su prisutni značajni utjecaji slobodne površine, što ga čini pogodnim za određivanje valnih opterećenja. U ovom radu je prikazan proračun opterećenja vertikalnog cilindra uslijed nailaska harmonijskih valova. Rezultati su uspoređeni s eksperimentalnim podacima. Uz to je prikazana simulacija ekstremnog vala (eng. „freak wave“), koja pokazuje mogućnost određivanja opterećenja uslijed ovakvih pojava
Gender influence on professional satisfaction and gender issue perception among young oncologists. A survey of the Young Oncologists Working Group of the Italian Association of Medical Oncology (AIOM)
Background:
The professional gender gap is increasingly recognised in oncology. We explored gender issues perception and gender influence on professional satisfaction/gratification among young Italian oncologists.
Methods:
Italian oncologists aged 6440 years and members of the Italian Association of Medical Oncology were invited to participate in an online survey addressing workload/burnout, satisfaction in professional abilities and relations, relevant factors for professional gratification, and gender barriers. \u3c72 test for general association or \u3c72 test for trend was used to analyse the data.
Results:
201 young oncologists participated in the survey: 67% female, 71% aged 30-40 years, 41% still in training and 82% without children. Women and men were equally poorly satisfied by the relations with people occupying superior hierarchical positions. There was heterogeneity between women and men in current (p=0.011) and expected future (p=0.007) satisfaction in professional abilities: women were more satisfied by current empathy and relations with colleagues and were more confident in their future managerial and team leader skills. The most important elements for professional gratification indicated by all participants were, in general, work-life balance (36%) and intellectual stimulation/research (32%); specifically for women, work-life balance (48%) and intellectual stimulation/research (20%); and specifically for men, career (29%) and social prestige/recognition (26%). Heterogeneity within the same gender emerged. For example, the elements indicated by men as the most important were intellectual stimulation/research (39%) and work-life balance (21%) in general, versus social prestige/recognition (24%) and career (24%), respectively, specifically for men (p<0.0001). More women versus men perceived gender issue as an actual problem (60% vs 38%, p=0.03); men underestimated gender barriers to women's career (p=0.011).
Conclusions:
Satisfaction in professional abilities varied by gender. Work-life balance is important for both women and men. Stereotypes about gender issues may be present. Gender issue is an actual problem for young oncologists, mostly perceived by women
A lack of classical Cepheids in the inner part of the Galactic disk
Recent large-scale infrared surveys have been revealing stellar populations
in the inner Galaxy seen through strong interstellar extinction in the disk. In
particular, classical Cepheids with their period-luminosity and period-age
relations are useful tracers of Galactic structure and evolution. Interesting
groups of Cepheids reported recently include four Cepheids in the Nuclear
Stellar Disk (NSD), about 200 pc around the Galactic Centre, found by Matsunaga
et al. and those spread across the inner part of the disk reported by Dekany
and collaborators. We here report our discovery of nearly thirty classical
Cepheids towards the bulge region, some of which are common with Dekany et al.,
and discuss the large impact of the reddening correction on distance estimates
for these objects. Assuming that the four Cepheids in the NSD are located at
the distance of the Galactic Centre and that the near-infrared extinction law,
i.e. wavelength dependency of the interstellar extinction, is not
systematically different between the NSD and other bulge lines-of-sight, most
of the other Cepheids presented here are located significantly further than the
Galactic Centre. This suggests a lack of Cepheids in the inner 2.5 kpc region
of the Galactic disk except the NSD. Recent radio observations show a similar
distribution of star-forming regions.Comment: 8 pages, 4 figures, accepted for publication in MNRA
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