22,087 research outputs found
Logarithmic variance profiles and the corresponding f-1 spectra of temperature fluctuations in turbulent Rayleigh-Bénard convection
No full textWe report experimental results for the temperature variance 2(z) and the corresponding frequency spectra P(f) in turbulent Rayleigh-Bénard convection (RBC) in a cylindrical sample of aspect ratioT= D/L = 1:00 (D = 1:12 m is the diameter and L = 1:12 m the height). The measurements were conducted in the Rayleigh-number range 1011 < Ra < 1:35 1014 and Pr ' 0:8. For Ra = 1:35x1014, 2(z) could be described well by a logarithmic dependence on the vertical position z in a range of z 1 < z < z 2 with z 1 ' 70 and z 2 = 0:1L. Here L=(2Nu) is the thickness of a thin thermal sublayer adjacent to the horizontal plate where the heat flux (denoted by the Nusselt number Nu) is carried mostly by thermal diffusion. In the log layer, we found that the temperature spectra had a significant frequency range over which P(f) f with close to 1. As Ra decreased, increased so that the log layer became thinner. At Ra = 2:05 1011, z 2 < z 1 and therefore there was no range for a log layer. Correspondingly, the temperature spectrum near the horizontal plate did not have the f1 scaling form either
Preparation of Degradable Superhydrophobic Mg/P/Z/F/H Composite Materials and Their Anticorrosion
Full text linkIn this study, the degradable superhydrophobic Mg/P/Z/F/H (magnesium/poly(-caprolactone)/zinc oxide/1H,1H,2H,2H-perfluorodecyltriethoxysilane (PFDTES)/heating process) composite materials were prepared through dip-coating method and heating process, for enhancing the corrosion resistance of the AZ91D magnesium alloys. The electrochemical measurements revealed that the Mg/P/Z/F/H materials significantly improved the corrosion resistance of the magnesium alloys in 3.5 wt.% NaCl. The Mg/P/Z/F/H composite materials exhibited efficient self-cleaning properties, good adhesion strength, and stability in wet atmosphere
Modulus-based iterative methods for constrained Tikhonov regularization
Full text linkTikhonov regularization is one of the most popular methods for the solution of linear discrete ill-posed problems. In many applications the desired solution is known to lie in the nonnegative cone. It is then natural to require that the approximate solution determined by Tikhonov regularization also lies in this cone. The present paper describes two iterative methods, that employ modulus-based iterative methods, to compute approximate solutions in the nonnegative cone of large-scale Tikhonov regularization problems. The first method considered consists of two steps: first the given linear discrete ill-posed problem is reduced to a small problem by a Krylov subspace method, and then the reduced Tikhonov regularization problems so obtained is solved. The second method described explores the structure of certain image restoration problems. Computed examples illustrate the performances of these methods
Some formulas for the Appell function F 1 (a, b, b′; c; w, z)
No full textSome new relations for the Appell function F 1 (a, b, b′; c; w, z) are obtained including differentiation and integration formulas, integral representations, series and recurrence relations. Some integrals are given which can be expressed in terms of F 1 and confluent Appell functions (Humbert functions) Φ1, Φ2, Φ
The influence of tourism on the sustaining of vernacular architechtural tradition embodied in the Bai and Naxi dwellings in Yunnan, China.
No full textYunnan is an economically underdeveloped region in south-western China, in which many ethnic settlements are preserved well. Within the last two decades, many ethnic communities at a grass-roots social level have been conducting a series of tourism-related developments of Bai and Naxi dwellings in Yunnan. They are altering, restoring, rebuilding, refurbishing and renewing ordinary Bai or Naxi dwellings into multi-function dwellings, which are not only the residential homes of families, but are also capable of providing an exotic cultural experience for tourists‘ consumption. Nevertheless, Bai and Naxi dwellings are representations of a living culture, embodying a complex set of vernacular architectural traditions which have been transmitted for many generations. When the Bai and Naxi dwellings are involved in tourism development, the transmission and adaptation of these vernacular architectural traditions are changed, and the manner in which such traditions aresustained in new circumstances becomes an interesting problem. This study explores the influence of tourism development on sustaining the vernacular architectural tradition embodied in Bai and Naxi dwellings in Yunnan, China. The researcher has conducted three rounds of fieldwork, choosing 30 Bai and Naxi dwellings involved in tourism development, from four ethnic minority settlements in Yunnan, for investigation. Observation, interview and questionnaire have been applied to collect data, and template analysis has been used to analyse the data. The results of the analysis show that if tourism development is conducted mainly at a community level, itcan enhance the sustaining of the vernacular architectural tradition embodied in Bai and Naxi dwellings. In summary, the sustaining of vernacular architectural tradition is not simply influenced by the nature of tourism, but is highly dependent on the social level of the developers, the construction pattern they choose, and the socio-cultural interaction they produce
Lyman break galaxies and the star formation rate of the Universe at z ~ 6
Full text linkWe determine the space density of UV-luminous starburst galaxies at z≈ 6 using deep HST ACS SDSS-i′ (F775W) and SDSS-z′ (F850LP) and VLT ISAAC J and Ks band imaging of the Chandra Deep Field South. We find eight galaxies and one star with (i′−z′) > 1.5 to a depth of z′AB= 25.6 (an 8σ detection in each of the 3 available ACS epochs). This corresponds to an unobscured star formation rate of ≈15 h−270 M⊙ yr−1 at z= 5.9, equivalent to L* for the Lyman-break population at z= 3–4 (ΩΛ= 0.7, ΩM= 0.3). We are sensitive to star-forming galaxies at 5.6 ≲z≲ 7.0 with an effective comoving volume of ≈1.8 × 105h−370 Mpc3 after accounting for incompleteness at the higher redshifts due to luminosity bias. This volume should encompass the primeval subgalactic-scale fragments of the progenitors of about a thousand L* galaxies at the current epoch. We determine a volume-averaged global star formation rate of (6.7 ± 2.7) × 10−4h70 M⊙ yr−1 Mpc−3 at z∼ 6 from rest-frame UV selected starbursts at the bright end of the luminosity function: this is a lower limit because of dust obscuration and galaxies below our sensitivity limit. This measurement shows that at z∼ 6 the star formation density at the bright end is a factor of ∼6 times less than that determined by Steidel et al. for a comparable sample of UV-selected galaxies at z= 3–4, and so extends our knowledge of the star formation history of the Universe to earlier times than previous work and into the epoch where reionization may have occurred
Author Response
No full textRahmatinejad Z, Hoseini B, Pourmand A, Reihani H, Rahmatinejad F, Eslami S, Author Response. Indian J Crit Care Med 2024;28(2):183-184
Identity of a historic garden: The view of the international literature and committies on the role of the botanical elements
No full textElsevier
Urban Forestry & Urban Greening
Volume 101
, November 2024, 128501
Urban Forestry & Urban Greening
Identity of a historic garden: The view of the international literature and committies on the role of the botanical elements
Author links open overlay panel
Z. Hosseini a
,
F. Bartoli a b
,
M.A. Pontrandolfi a
,
G. Caneva a
Show more
Add to Mendeley
Share
Cite
https://doi.org/10.1016/j.ufug.2024.128501
Get rights and content
Abstract
Historic gardens are conceptualized within various cultural and legal frameworks. This research aims to unravel the complexities of the historic garden identity through the lens of international regulations, national laws, and scientific literature to reveal differences in the perception of their botanical elements. We employed a combined analytical approach, using recommendations from related international institutions (i.e. UNESCO, ICCROM, and ICOMOS), national legislation, and a review of scientific literature. The analysis identified 25 documents related to the keywords: nature, landscape, site, and garden; however, only six mentioned gardens, and just one (The Florence Charter., 1982) explicitly addressed historic gardens. Only 7 % of UNESCO member countries (197) have specific provisions for historic gardens. Within them, a diverse range of definitions and standards has resulted in discrepancies in how historic gardens are recognized and conserved across different jurisdictions. Some countries have well-defined categories for garden heritage, while others offer limited or broad categorizations that may obscure garden identities. The findings underscore the necessity for more coherent international regulations that adequately reflect historic gardens' cultural and botanical significance. The study also highlighted the overlooked role of botanical elements, since only four countries included botanical value as an explicit criterion in their legal designations, suggesting that the botanical aspect is often considered within a larger ecological and geographical context. The imperative to preserve these living legacies within the broader context of cultural heritage also became apparent
On some properties of a generalized class of close-to-starlike functions
No full textIn this paper, we consider a new class of close-to-starlike functions denoted by ? CS?,? , defined by the Carlson-Shaffer operator L??,? ? . Let S denote the class of analytic univalent functions f defined by ? ? ? ? ? ? ? 2 , n n n f z z a z then ? ?CS?,? f if f satisfy the condition ? ?? ?? ? ? ? z E g z f z ? ? ? ? ? ? ? ? 0, , Re L ? ? , where ? ? ? ? ? ? ?? ? ? ? ? ? ? ? 2 1 1 , n n n n n f z z a z ? ? L ? ? and g(z) is a starlike function. Properties of the class ? CS?,? such as the coefficient bounds, growth and distortion theorems and radius results are investigated
Writing of(f) family : Sarah’s family hand-me-downs
No full textThis chapter explores family estrangement through the lens of the trauma of transgenerational abandonment. Applying the notion of family hand-me-downs, the author makes use of speculative (real and imagined) autoethnography (Purnell, 2015), to situate relational stories from five family generations. These speculative, relational stories are impacted by traumatic memories, buried deep as affective, psychic, shame-binds. Embodied shame is transmitted down through the generations, as cultural and family scripts—by family members who have become haunted by shameful secrets and silences. Sometimes these ghostly scripts occur unconsciously, and other times, consciously. Breaking the silence of family secrets is never easy. The author hopes that writing trauma stories (relational and speculative) through imagination, adding just a touch of reality, stories can become the impetus for identification and empathy bringing with it the possibility of repairing broken relationships, disconnected by the impact of transgenerational trauma of abandonment. It is only by healing the wounds of the past, bought on by family estrangement, that new relational stories may unfold ending stories of embodied, toxic shame, so that new relationships can flourish
- …
