Introduction of a Cooling-Fan Efficiency Index

Schiavon, Stefano; Melikov, Arsen Krikor

doi:10.1080/10789669.2009.10390882

Cited by 34 publications

(25 citation statements)

References 19 publications

(17 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Convergence is typically achieved in no more than a couple of iterations. Readers interested in further details on both the models and EZ_Ages details on the models and age/abundance determination methods are referred to Graves & Schiavon (2008) and Schiavon (2007). In this paper, we focus on the results for ages and [Fe/H], deferring the discussion of abundance ratios to a forthcoming paper (Schiavon et al 2010).…”

Section: Metallicities and Ages Via Population Synthesismentioning

confidence: 99%

“…These data, taken typically through one fiber only, were reduced following the same procedure as for the GC spectra and provided small zero-point shifts used to convert the instrumental EWs into the Lick system. The details of the transformation to the standard Lick system will be covered in a subsequent paper (Schiavon et al 2010). Figure 6 shows the distribution of several selected indices: Fe 2 , Mg b, H , and Ca4227.…”

Section: Line Indices and Their Distributionmentioning

confidence: 99%

“…Both ages and chemical composition estimates for the M31 GCs were obtained simultaneously from comparisons of the Lick indices with the stellar population synthesis (SPS) models from Schiavon (2007). The details of the models are contained in that paper, but in brief, polynomial functions describing the relations between various spectral indices and physical parameters of a stellar library were computed, and then combined with theoretical isochrones in order to produce predictions of integrated indices of single stellar populations.…”

Section: Metallicities and Ages Via Population Synthesismentioning

confidence: 99%

“…This may possibly result from a combination of model zero-point uncertainties due to inadequate treatment of stellar luminosity function and abundance ratio effects (e.g., Schiavon et al 2002) and Balmerline infill from evolved giants and/or intra-cluster medium (Schiavon et al 2005)-see Poole et al (2009) for a discussion of this issue. Second, the treatment of horizontal branch (HB) stars in Padova isochrones, adopted in the Schiavon (2007) models, is such that there are blue HB stars in the metallicity range spanned by those models. As a result, metal-poor clusters with a blue HB tend to have stronger Balmer lines than predicted by models for the same age and metallicity, with the result that their ages are artificially younger according to the models.…”

Section: Caveatsmentioning

confidence: 99%

“…EZ_Ages 6 is an IDL implementation of a method developed by Schiavon (2007) to estimate the luminosity-weighted ages of stellar populations, as well as their luminosity-weighted abundances of iron, magnesium, carbon, nitrogen, and calcium, from Lick indices measured in their integrated spectra. The method has been successfully tested through application to Galactic GCs with known ages and chemical composition.…”

Section: Metallicities and Ages Via Population Synthesismentioning

confidence: 99%

See 4 more Smart Citations

Star Clusters in M31. Ii. Old Cluster Metallicities and Ages From Hectospec Data

Caldwell

Schiavon

Morrison

et al. 2011

The Astronomical Journal

166

400

View full text Add to dashboard Cite

We present new high signal-to-noise spectroscopic data on the M31 globular cluster (GC) system, obtained with the Hectospec multifiber spectrograph on the 6.5 m MMT. More than 300 clusters have been observed at a resolution of 5 Å and with a median S/N of 75 per Å, providing velocities with a median uncertainty of 6 km s −1 . The primary focus of this paper is the determination of mean cluster metallicities, ages, and reddenings. Metallicities were estimated using a calibration of Lick indices with [Fe/H] provided by Galactic GCs. These match well the metallicities of 24 M31 clusters determined from Hubble Space Telescope color-magnitude diagrams, the differences having an rms of 0.2 dex. The metallicity distribution is not generally bimodal, in strong distinction with the bimodal Galactic globular distribution. Rather, the M31 distribution shows a broad peak, centered at [Fe/H] = −1, possibly with minor peaks at [Fe/H] = −1.4, −0.7, and −0.2, suggesting that the cluster systems of M31 and the Milky Way had different formation histories. Ages for clusters with [Fe/H] > −1 were determined using the automatic stellar population analysis program EZ_Ages. We find no evidence for massive clusters in M31 with intermediate ages, those between 2 and 6 Gyr. Moreover, we find that the mean ages of the old GCs are remarkably constant over about a decade in metallicity (−0.95 [Fe/H] 0.0).

show abstract

Section: Metallicities and Ages Via Population Synthesismentioning

confidence: 99%

Section: Line Indices and Their Distributionmentioning

confidence: 99%

Section: Metallicities and Ages Via Population Synthesismentioning

confidence: 99%

Section: Caveatsmentioning

confidence: 99%

Section: Metallicities and Ages Via Population Synthesismentioning

confidence: 99%

See 3 more Smart Citations

Star Clusters in M31. Ii. Old Cluster Metallicities and Ages From Hectospec Data

Caldwell

Schiavon

Morrison

et al. 2011

The Astronomical Journal

166

400

View full text Add to dashboard Cite

show abstract

Comparison of stationary and transient RANS modelling

et al. 2020

View full text Add to dashboard Cite

Vergleich stationärer und transienter RANS‐Modellierung zur Analyse der räumlichen Geschwindigkeitsverteilung unter Anwendung deckenintegrierter Ventilatoren Deckenventilatoren ermöglichen eine Erhöhung der lokalen Luftgeschwindigkeit am menschlichen Körper. Durch die damit verbundene Wärmeabfuhr steigt die Nutzertoleranz gegenüber warmen Umgebungen. In dieser Studie wird die Anwendung statistischer Turbulenzmodelle (RANS) zur Modellierung der durch deckenintegrierte Ventilatoren induzierten Luftströmung dargestellt. Ein besonderer Fokus wird hierbei auf den Vergleich zwischen stationärer und transienter Simulation gesetzt. Die Ergebnisse der CFD‐Simulation (mittels Fluent) werden mit Messergebnissen der horizontalen Geschwindigkeitsverteilung verglichen. Die Studie zeigt, dass die transiente Simulation mittels Realizable k‐ε Modell zwar ein stabiles Konvergenzverhalten sowohl seitens der Residuen, als auch der Zielwerte aufzeigt, im Vergleich zur stationären Berechnung jedoch der mittlere absolute Fehler in 1,4 m Entfernung zum Ventilator größer ist, obwohl die stationäre Modellierung mittels des Multiple Reference Frame (MRF)‐Verfahrens ein nicht physikalisch begründbares Geschwindigkeitsfeld in der unmittelbaren Umgebung des Ventilators hervorruft. Die Ursache dafür, dass die stationäre Lösung mittels MRF nicht konvergiert, ist auf die räumliche Begrenzung der rotierenden Zone zurückzuführen, so wie es bei deckenintegrierten Ventilatoren durch das Ventilatorgehäuse der Fall ist. Demgegenüber bei frei im Raum hängenden Ventilatoren die rotierende Zone entsprechend adaptiert und das Konvergenzverhalten verbessert werden kann.

show abstract

Integrated Assessment of Urban Overheating Impacts on Human Life

Nazarian

Krayenhoff

Bechtel

et al. 2021

Preprint

View full text Add to dashboard Cite

Urban overheating, driven by global climate change and urban development, is a major contemporary challenge that substantially impacts urban livability and sustainability. Overheating represents a multifaceted threat to the well-being, performance, and health of individuals as well as the energy efficiency and economy of cities, and it is influenced by complex interactions between building, city, and global scale climates. In recent decades, extensive discipline-specific research has characterized urban heat and assessed its implications on human life, including ongoing efforts to bridge neighboring disciplines. The research horizon now encompasses complex problems involving a wide range of disciplines, and therefore comprehensive and integrated assessments are needed that address such interdisciplinarity. Here, our objective is to go beyond a review of existing literature and instead provide a broad overview and integrated assessments of urban overheating, defining holistic pathways for addressing the impacts on human life. We (a) detail the characterization of heat hazards and exposure across different scales and in various disciplines, (b) identify individual sensitivities to urban overheating that increase vulnerability and cause adverse impacts in different populations, (c) elaborate on adaptive capacities that individuals and cities can adopt, (d) document the impacts of urban overheating on health and energy, and (e) discuss frontiers of theoretical and applied urban climatology, built environment design, and governance toward reduction of heat exposure and vulnerability at various scales. The most critical challenges in future research and application are identified, targeting both the gaps and the need for greater integration in overheating assessments.Plain Language Summary Many major cities are faced with the compounding effects of climate change and rapid urbanization. One of the main challenges that result is urban overheating, which leads to negative impacts on human life (deteriorating health, productivity, and well-being) and urban energy systems. Heat exposure in cities, however, is only the trigger and there are other factors that influence impacts. Urban heat vulnerability exists when sensitive people and infrastructure are exposed to extreme heat, and negative impacts ensue if there is a lack of capacity to respond and adapt. Accordingly, to combat overheating challenges, it is critical that multidisciplinary solutions are integrated to mitigate exposure, reduce sensitivity, and increase adaptive capacities. This paper provides an integrated assessment of urban overheating literature, defining pathways for addressing the impacts on human life. We review the state-of-the-art methods used to quantify heat hazards and exposure, detail the sensitivity of people and infrastructure to overheating, and elaborate on the adaptive capacities that individuals and cities can undertake in response. We provide recommendations for both researchers and policymakers that will minimize overheating impacts. Thes...

show abstract

Introduction of a Cooling-Fan Efficiency Index

Abstract: In a warm environment, air movement with elevated velocity is a well-known cooling strategy.The local air movement is typically generated by cooling fans (e.g., ceiling fan,

Cited by 34 publications

References 19 publications

Star Clusters in M31. Ii. Old Cluster Metallicities and Ages From Hectospec Data

Star Clusters in M31. Ii. Old Cluster Metallicities and Ages From Hectospec Data

Comparison of stationary and transient RANS modelling

Integrated Assessment of Urban Overheating Impacts on Human Life

Contact Info

Product

Resources

About