1,850 research outputs found
An Analysis of ALMA Deep Fields and the Perceived Dearth of High-z Galaxies
Deep, pencil-beam surveys from ALMA at 1.1-1.3mm have uncovered an apparent
absence of high-redshift dusty galaxies, with existing redshift distributions
peaking around . This has led to a perceived dearth of dusty
systems at , and the conclusion, according to some models, that the early
Universe was relatively dust-poor. In this paper, we extend the backward
evolution galaxy model described by Casey et al. (2018) to the ALMA regime (in
depth and area) and determine that the measured number counts and redshift
distributions from ALMA deep field surveys are fully consistent with
constraints of the infrared luminosity function (IRLF) at determined by
single-dish submillimeter and millimeter surveys conducted on much larger
angular scales (deg). We find that measured 1.1-1.3mm number
counts are most constraining for the measurement of the faint-end slope of the
IRLF at . Recent
studies have suggested that UV-selected galaxies at may be particularly
dust-poor, but we find their millimeter-wave emission cannot rule out
consistency with the Calzetti dust attenuation law even by assuming relatively
typical, cold-dust (K) SEDs. Our models suggest that
the design of ALMA deep fields requires substantial revision to constrain the
prevalence of early Universe obscured starbursts. The most promising
avenue for detection and characterization of such early dusty galaxies will
come from future ALMA 2mm blank field surveys covering a few hundred
arcmin and the combination of existing and future dual-purpose 3mm
datasets.Comment: 21 pages, 12 figures, accepted for publication in Ap
Avaliação em laboratório do comportamento térmico de soluções construtivas em madeira
O presente trabalho apresenta a avaliação do comportamento térmico de quatro soluções
construtivas integralmente em madeira, recorrendo à previsão e análise experimental do seu
desempenho térmico. Foram avaliadas quatro soluções construtivas representativas do mercado, três
delas tendo por base troncos de madeira e uma outra do tipo entramado de madeira.
As principais tipologias de habitações que se encontram no mercado são, essencialmente casas em
painel e em troncos de madeira tratada. As casas de troncos possuem um aspeto mais rústico sendo
usualmente utilizadas em ambientes de montanha, estas recorrem a ligações metálicas entre troncos
e entre paredes, podendo ou não utilizar isolamento térmico colocado no interior da parede. As casas
em painel são, geralmente, do tipo modular, o que permite uma rápida execução e posterior
expansão. Aliadas a uma arquitetura moderna e cuidada, são difíceis de distinguir das casas em
alvenaria.
O objetivo central do trabalho foi o de aumentar o conhecimento científico e técnico relativo ao
comportamento térmico das soluções construtivas em madeira, colmatando a ausência de valores
relativos ao coeficiente de transmissão térmica à disposição de técnicos e investigadores. Foi
analisado o desempenho térmico destas soluções construtivas segundo a regulamentação térmica
atual (RCCTE) [1], posteriormente estes resultados foram comparados com as soluções de
construções mais comuns em Portugal.
A análise dos resultados experimentais obtidos permitiu verificar que os coeficientes de transmissão
térmica destas soluções cumprem os requisitos mínimos. Sendo a solução com estrutura leve de
madeira revestida com aglomerados e preenchida com lã-de-rocha a que apresenta melhor
desempenho. Comparativamente com os sistemas construtivos mais comuns de paredes de alvenaria
as soluções construtivas com estrutura de madeira apresentam um comportamento térmico superiorRusticas
Effect of Nonionic Surfactants on the Crystallinity and Thermal Stability of Poly(vinyl alcohol) Film
In this study, poly(vinyl alcohol) (PVA)/surfactant films were prepared by casting technique. Two nonionic surfactants with different alkyl chain lenghts (Tween 20 and Tween 40) were used. PVA/Tween 20 and PVA/Tween 40 films were characterized by means of Fourier Transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). FTIR spectra of PVA/Tween films indicated the presence of hydrogen bond interactions between the Tween surfactants and PVA. XRD results showed that the incorporation of Tween 20 and 40 into the PVA film decreased the crystallinity of PVA.TGA curves revealed an increase in the thermal stability of PVA film in the presence of the surfactants.
DOI: http://dx.doi.org/10.17807/orbital.v12i4.151
Lei de licitações e contratos: comentada: Lei nº 14.133/2021
Divulgação dos SUMÁRIOS das obras recentemente incorporadas ao acervo da Biblioteca Ministro Oscar Saraiva do STJ. Em respeito à Lei de Direitos Autorais, não disponibilizamos a obra na íntegra.Localização na estante: 351.712.2(81)(094) Coment. L525lcCoordenado por: Alexandre Jorge Carneiro da Cunha Filho, Roberto Ricomini Piccelli e Carmen Silvia L. de Arrud
The Brightest Galaxies in the Dark Ages: Galaxies' Dust Continuum Emission During the Reionization Era
Though half of cosmic starlight is absorbed by dust and reradiated at long
wavelengths (3m-3mm), constraints on the infrared through millimeter
galaxy luminosity function (the `IRLF') are poor in comparison to the
rest-frame ultraviolet and optical galaxy luminosity function, particularly at
z>2.5. Here we present a backward evolution model for interpreting number
counts, redshift distributions, and cross-band flux density correlations in the
infrared and submillimeter sky, from 70m-2mm, using a model for the IRLF
out to the epoch of reionization. Mock submillimeter maps are generated by
injecting sources according to the prescribed IRLF and flux densities drawn
from model spectral energy distributions that mirror the distribution of SEDs
observed in dusty star-forming galaxies (DSFGs). We explore two extreme
hypothetical case-studies: a dust-poor early Universe model, where DSFGs
contribute negligibly (10%) to the integrated star-formation rate density at
, and an alternate dust-rich early Universe model, where DSFGs dominate
90% of star-formation. We find that current submm/mm datasets do
not clearly rule out either of these extreme models. We suggest that future
surveys at 2mm will be crucial to measuring the IRLF beyond . The model
framework developed in this paper serves as a unique tool for the
interpretation of multiwavelength IR/submm extragalactic datasets and will
enable more refined constraints on the IRLF than can be made from direct
measurements of individual galaxies' integrated dust emission.Comment: 34 pages, 16 figures, accepted for publication in Ap
Novo marco regulatório do saneamento básico no Brasil: estudos sobre a nova Lei n° 14.026/2020
- Divulgação dos SUMÁRIOS das obras recentemente incorporadas ao acervo da Biblioteca Ministro Oscar Saraiva do STJ. Em respeito à Lei de Direitos Autorais, não disponibilizamos a obra na íntegra.- Localização na estante: 628:35.078.2(81) N945ma- Coordenado por: Alexandre Jorge Carneiro da Cunha Filho, Carmem silva L. de Arruda, Guilherme Corona Rodrigues Lima e Rodrigo de Pinho Bertoccelli
Differential microRNA Profile in Operational Tolerance: A Potential Role in Favoring Cell Survival
Background: Operational tolerance (OT) is a state of graft functional stability that occurs after at least 1 year of immunosuppressant withdrawal. MicroRNAs (microRNA) are small non-coding RNAs that downregulate messenger RNA/protein expression of innumerous molecules and are critical for homeostasis. We investigated whether OT in kidney transplantation displays a differential microRNA profile, which would suggest that microRNAs participate in Operational Tolerance mechanisms, and may reveal potential molecular pathways.Methods: We first compared serum microRNA in OT (n = 8) with chronic rejection (CR) (n = 5) and healthy individuals (HI) (n = 5), using a 768-microRNA qPCR-panel. We used the Thermo Fisher Cloud computing platform to compare the levels of microRNAs in the OT group in relation to the other study groups. We performed validation experiments for miR-885-5p, by q-PCR, in a larger number of study subjects (OT = 8, CR = 12, HI = 12), as individual samples.Results: We detected a differential microRNA profile in OT vs. its opposing clinical outcome—CR—suggesting that microRNAs may integrate transplantation tolerance mechanisms. Some miRNAs were detected at higher levels in OT: miR-885-5p, miR-331-3p, miR-27a-5p vs. CR; others, we found at lower levels: miR-1233-3p, miR-572, miR-638, miR-1260a. Considering highly predicted/experimentally demonstrated targets of these miRNAs, bioinformatics analysis revealed that the granzyme B, and death receptor pathways are dominant, suggesting that cell death regulation integrates transplantation tolerance mechanisms. We confirmed higher miR-885-5p levels in OT vs. CR, and vs. HI, in a larger number of subjects.Conclusions: We propose that epigenetics mechanisms involving microRNAs may integrate human transplantation tolerance mechanisms, and regulate key members of the cell death/survival signaling. miR-885-5p could favor cell survival in OT by diminishing the levels of CRADD/RAIDD and CASP3. Nonetheless, given the nature of any complex phenomenon in humans, only cumulative data will help to determine whether this microRNA differential profile may be related to the cause or consequence of operational tolerance
Effect of Nonionic Surfactants on the Crystallinity and Thermal Stability of Poly(vinyl alcohol) Film
In this study, poly(vinyl alcohol) (PVA)/surfactant films were prepared by casting technique. Two nonionic surfactants with different alkyl chain lenghts (Tween 20 and Tween 40) were used. PVA/Tween 20 and PVA/Tween 40 films were characterized by means of Fourier Transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). FTIR spectra of PVA/Tween films indicated the presence of hydrogen bond interactions between the Tween surfactants and PVA. XRD results showed that the incorporation of Tween 20 and 40 into the PVA film decreased the crystallinity of PVA.TGA curves revealed an increase in the thermal stability of PVA film in the presence of the surfactants.
DOI: http://dx.doi.org/10.17807/orbital.v12i4.151
Novo marco regulatório do saneamento básico no Brasil: estudos sobre a nova Lei n° 14.026/2020
- Divulgação dos SUMÁRIOS das obras recentemente incorporadas ao acervo da Biblioteca Ministro Oscar Saraiva do STJ. Em respeito à Lei de Direitos Autorais, não disponibilizamos a obra na íntegra.- Localização na estante: 628:35.078.2(81) N945ma- Coordenado por: Alexandre Jorge Carneiro da Cunha Filho, Carmen Silvia Lima de Arruda, Guilherme Corona Rodrigues Lima e Rodrigo Pinho Betoccelli
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