181 research outputs found
How to manage and minimize food waste in the hotel industry? An exploratory research
Purpose – The hospitality industry is responsible for significant amounts of waste, more than one-third
of which is food waste. Through the comparison between an Italian and a Romanian hotel, this paper
aims to provide a better understanding of food waste management trends in the hotel industry as well
as to highlight hotel kitchens and hotel food services weaknesses and opportunities to minimize food
waste.
Design/methodology/approach – In-depth interviews, personal communication and observations were
conducted to investigate food service planning, food procurement and food waste management, as well
as to better comprehend current individuals’ understanding and attitudes, infrastructures, legislative
culture and opportunities either from the managerial and the employees’ perspective. Data were
analyzed according to a content analysis approach.
Findings – Three critical hot spots emerged from the analysis: prediction and check of guests’
attendance, communication and transparency with local suppliers and among departments within the
unit and purchasing frequency and perishable food provisioning. The accurate forecasting of the number
of guests and their nationality is fundamental in avoiding food waste at food service, as well as
implementing transparency and communication with local suppliers.
Originality/value – Although academia and authorities have recognized the crucial importance of food
waste management, food waste research in the hotel industry remains under-researched. The present
exploratory research contributes to the scarce empirical studies about hotels’ food waste, giving
theoretical and managerial recommendations for supporting further studies, highlighting the need for
formal deals between hotels and local suppliers (food procurement), as well as the importance of foodnetworks
that holds together companies, retailers and charities (food donation)
Explaining potentially unfair clauses to the consumer with the claudette tool
This paper presents the latest developments of the use of memory network models in detecting and explaining unfair terms in online consumer contracts. We extend the CLAUDETTE tool for the detection of potentially unfair clauses in online Terms of Service, by providing to the users the explanations of unfairness (legal rationales) for five different categories: Arbitration, unilateral change, content removal, unilateral termination, and limitation of liability
Multiple stellar populations in Magellanic Cloud clusters. V. The split main sequence of the young cluster NGC1866
One of the most unexpected results in the field of stellar populations of the
last few years, is the discovery that some Magellanic-Cloud globular clusters
younger than ~400 Myr, exhibit bimodal main sequences (MSs) in their
color-magnitude diagrams (CMDs). Moreover, these young clusters host an
extended main sequence turn off (eMSTO) in close analogy with what is observed
in most ~1-2 Gyr old clusters of both Magellanic Clouds.
We use high-precision Hubble-Space-Telescope photometry to study the young
star cluster NGC1866 in the Large Magellanic Cloud. We discover an eMSTO and a
split MS. The analysis of the CMD reveals that (i) the blue MS is the less
populous one, hosting about one-third of the total number of MS stars; (ii)
red-MS stars are more centrally concentrated than blue-MS stars; (iii) the
fraction of blue-MS stars with respect to the total number of MS stars drops by
a factor of ~2 in the upper MS with F814W <~19.7.
The comparison between the observed CMDs and stellar models reveals that the
observations are consistent with ~200 Myr old highly-rotating stars on the
red-MS, with rotation close to critical value, plus a non-rotating stellar
population spanning an age interval between ~140 and 220 Myr, on the blue-MS.
Noticeable, neither stellar populations with different ages only, nor coeval
stellar models with different rotation rates, properly reproduce the observed
split MS and eMSTO. We discuss these results in the context of the eMSTO and
multiple MS phenomenon.Comment: 11 pages, 11 figures, accepted for publication in MNRA
The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters. XIX. A Chemical Tagging of the Multiple Stellar Populations Over the Chromosome Maps
The HST UV Survey of Globular Clusters (GCs) has investigated GCs and their
stellar populations. In previous papers of this series we have introduced a
pseudo two-color diagram, "chromosome map" (ChM), that maximises the separation
between the multiple populations. We have identified two main classes of GCs:
Type I (~83% of the objects) and Type II, both hosting two main groups of
stars, referred to in this series as first (1G) and second generation (2G).
Type II clusters exhibit two or more parallel sequences of 1G and 2G stars in
their ChMs. We exploit elemental abundances from literature to assign the
chemical composition to the distinct populations as identified on the ChMs of
29 GCs. We find that stars in different regions of the ChM have different
composition: 1G stars share the same light-element content as field stars,
while 2G stars are enhanced in N, Na and depleted in O. Stars enhanced in Al
and depleted in Mg populate the extreme regions of the ChM. We investigate the
color spread among 1G stars observed in many GCs, and find no evidence for
variations in light elements, whereas either a 0.1 dex Fe spread or a variation
in He remain to be verified. In the attempt of analysing the global properties
of the multiple populations, we have constructed a universal ChM, which
highlights that, though variegate, the phenomenon has some common pattern. The
universal ChM reveals a tight connection with Na, for which we have provided an
empirical relation. The additional ChM sequences typical of Type II GCs are
enhanced in metallicity and, often, in s elements. Omega Cen can be classified
as an extreme Type II GC, with a ChM displaying three main streams, each with
its own variations in chemical abundances. One of the most noticeable
differences is between the lower and upper streams, with the latter (associated
with higher He) having higher Fe and lower Li. We publicly release ChMs.Comment: 35 pages, 28 figures, 3 tables. Submitted to MNRA
On the kinematic separation of field and cluster stars across the Bulge globular NGC 6528
We present deep and precise multi-band photometry of the Galactic Bulge
globular cluster NGC6528. The current dataset includes optical and
near-infrared images collected with ACS/WFC, WFC3/UVIS, and WFC3/IR on board
the Hubble Space Telescope. The images cover a time interval of almost ten
years and we have been able to carry out a proper-motion separation between
cluster and field stars. We performed a detailed comparison in the m_F814W,
m_F606W - m_F814W Color-Magnitude Diagram with two empirical calibrators
observed in the same bands. We found that NGC6528 is coeval with and more
metal-rich than 47Tuc. Moreover, it appears older and more metal-poor than the
super-metal-rich open cluster NGC6791. The current evidence is supported by
several diagnostics (red horizontal branch, red giant branch bump, shape of the
sub-giant branch, slope of the main sequence) that are minimally affected by
uncertainties in reddening and distance. We fit the optical observations with
theoretical isochrones based on a scaled-solar chemical mixture and found an
age of 11 +- 1 Gyr and an iron abundance slightly above solar ([Fe/H = +0.20).
The iron abundance and the old cluster age further support the recent
spectroscopic findings suggesting a rapid chemical enrichment of the Galactic
Bulge.Comment: 14 pages, 12 figures (2 at low resolution); added references;
corrected figure 3, 4, 5, 8 and 9; results unchanged. Erratum to be published
in Ap
The temperature distribution of horizontal branch stars: methods and first results
As part of a large project aimed at characterizing the ultraviolet (UV)
properties of globular clusters, we present here a theoretical and
observational analysis aimed at setting the framework for the determination of
horizontal branch (HB) temperature distributions. Indeed this is a crucial
information to understand the physical parameters shaping the HB morphology in
globular clusters and to interpret the UV emission from unresolved stellar
systems. We found that the use of zero age HB color-Teff relations is a robust
way to derive effective temperatures of individual HB stars. We investigated
the most suitable colors for temperature estimates, and the effect on the
color-Teff relations of variations of the initial chemical composition, and of
the evolution off the zero age horizontal branch. As a test case, we applied
our color-Teff calibrations to the Galactic globular cluster M15. The
photometry of M15 has been obtained with the Wide Field and Planetary Camera 2
on board the HST. The HB of M15 turned out to have a multimodal distribution,
with a main component peaked at Teff~8,000 K and confined below Teff~10,000 K.
The second component is peaked at Teff~14,000 K and extends up to Teff~20,000
K. The vast majority (~95%) of the HB stars in M15 is below 20,000 K, in
agreement with the lack of a well populated extreme HB observed in other
metal-poor globular clusters. We also verified that the temperatures derived
with our analysis are consistent with spectroscopic estimates available in the
literature.Comment: 13 pages, 13 figures. ApJ accepte
The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters. XVI. The helium abundance of multiple populations
Recent work, based on data from the Hubble Space Telescope (HST) UV Legacy
Survey of Galactic Globular Clusters (GCs), has revealed that all the analyzed
clusters host two groups of first- (1G) and second-generation (2G) stars. In
most GCs, both 1G and 2G stars host sub-stellar populations with different
chemical composition. We compare multi-wavelength HST photometry with synthetic
spectra to determine for the first time the average helium difference between
the 2G and 1G stars in a large sample of 57 GCs and the maximum helium
variation within each of them. We find that in all clusters 2G stars are
consistent with being enhanced in helium with respect to 1G. The maximum helium
variation ranges from less than 0.01 to more than 0.10 in helium mass fraction
and correlates with both the cluster mass and the color extension of the
horizontal branch (HB). These findings demonstrate that the internal helium
variation is one of the main (second) parameters governing the HB morphology.Comment: 26 pages, 19 figures, accepted for publications in MNRA
WFPC2 UV survey of Galactic globular clusters. The Horizontal Branch temperature distribution
Ultraviolet observations are the best tool to study hot stellar populations which emit most of their light at short wavelengths. As part of a large project devoted to the characterization of the UV properties of Galactic globular clusters (GGCs), we collected mid/far UV and optical images with the WFPC2@HST for 31 GGCs. These clusters cover a wide range in metallicity and structural parameters, thus representing an ideal sample for comparison with theoretical models. Here we present the first results from an ongoing analysis aimed at deriving the temperature distribution of Horizontal Branch stars in GGCs
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