658 research outputs found
Probing massive neutrinos with the Minkowski functionals of the galaxy distribution
The characteristic signatures of massive neutrinos on large-scale structure
(LSS), if fully captured, can be used to put a stringent constraint on their
mass sum, . Previous work utilizing N-body simulations has shown the
Minkowski functionals (MFs) of LSS can reveal the imprints of massive neutrinos
on LSS, provide important complementary information to two-point statistics and
significantly improve constraints on . In this work, we take a step
forward and apply the statistics to the biased tracers of LSS, i.e. the
galaxies, and in redshift space. We perform a Fisher matrix analysis and
quantify the constraining power of the MFs by using the Molino mock galaxy
catalogs, which are constructed based on the halo occupation distribution (HOD)
framework with parameters for the SDSS and -22 galaxy samples. We
find the MFs give tighter constraints on all of the cosmological parameters
that we consider than the power spectrum. The constraints on
, and from
the MFs are better by a factor of 1.9, 2.9, 3.7, 4.2, 2.5, and 5.7,
respectively, after marginalizing over the HOD parameters. Specifically, for
, we obtain a 1 constraint of 0.059 eV with the MFs alone for
a volume of only .Comment: 33 pages, 5 + 4 figures, 4 tables. To be submitted to JCAP. Comments
welcome. arXiv admin note: text overlap with arXiv:2204.0294
Indoor Air Quality Requirements in Green Building Certifications
International audienceGreen building certifications aim to achieve sustainable buildings that are healthy, energy-saving, and environmentally friendly. To construct healthy built environments for occupants, a high indoor environment quality (IEQ) has to be maintained. The goal of this paper is to analyze how and to what extent indoor air quality (IAQ), as a subset of IEQ, is taken into account in green building certifications worldwide. Thus, IAQ requirements were reviewed in 31 green building certifications from 30 countries worldwide. These certification programs include 13 countries in Asia, 9 in Europe, 5 in Americas, 2 in Oceania, and 1 in Africa. Fifty-five green building schemes were selected from among the 31 certifications. Rating systems are commonly used in green building schemes to evaluate the capability and level of a building to achieve life-cycle sustainability. The average contribution of IAQ to green building schemes worldwide is 2 7.5%. Volatile organic compounds (VOCs), formaldehyde, and carbon dioxide (CO2) are the indoor air pollutants most frequently considered. Ozone (O3) and semi-volatile organic compounds (SVOCs) are mentioned in less than 6.7% of the certifications worldwide. Emission source control, ventilation, and indoor air measurement are the three main pathways used in green building schemes for IAQ management. All of the certifications include ventilation as a way to manage IAQ. Emission source control is included in 77% of the certifications and is mainly targeted at building material emissions. Indoor air measurement is included in 65% of the certifications but may be optional
Probing massive neutrinos with the Minkowski functionals of large-scale structure
Massive neutrinos suppress the growth of structure under their free-streaming
scales. The effect is most prominent on small scales where the widely-used
two-point statistics can no longer capture the full information. In this work,
we study the signatures massive neutrinos leave on large-scale structure (LSS)
as revealed by its morphological properties, which are fully described by
Minkowski functionals (MFs), and quantify the constraints on the summed
neutrino mass from the MFs, by using publicly available N-body
simulations. We find the MFs provide important complementary information, and
give tighter constraints on than the power spectrum. Specifically,
depending on whether massive neutrinos are included in the density field (the
`m' field) or not (the `cb' field), we find the constraint on from
the MFs with a smoothing scale of Mpc is or times better
than that from the power spectrum. When the MFs are combined with the power
spectrum, they can improve the constraint on from the latter by a
factor of 63 for the `m' field and 5 for the `cb' field. Notably, when the `m'
field is used, the constraint on from the MFs can reach eV
with a volume of , while the combination of the MFs and
power spectrum can tighten this constraint to be eV, a
significance on detecting the minimum sum of the neutrino masses. For the `m'
field, we also find the and degeneracy is broken with the
MFs, leading to stronger constraints on all 6 cosmological parameters
considered in this work than the power spectrum.Comment: Accepted for publication in JCAP. Changes from the first version: add
figure 10, and minor text revisions. Matches accepted version. 33 pages, 10
figures, 2 table
A long-term dynamic model for predicting the concentration of semivolatile organic compounds in indoor environments: application to phthalates
International audienceSemivolatile organic compounds (SVOCs) in indoor environments can partition into the gas phase, airborne particles, and settled dust and onto available surfaces. A long-term dynamic model was developed to predict the hourly concentrations of SVOCs over a year in the gas phase, airborne particles, and settled dust and on each sink surface. The model takes into account mass transfer mechanisms, the reactivity of SVOCs with oxidants indoors, and the influence of four indoor environmental factors (the air temperature, relative humidity, concentration of indoor airborne particles, and air exchange rate) on the mass transfer parameters. The model was validated for DEHP (di-2-ethylhexyl phthalate) and BBzP (butyl benzyl phthalate) by comparing the predicted concentrations in all the phases with the measured concentrations obtained in an environmental chamber and a test house. The model was then used to predict the hourly averaged concentration of BBzP in all the phases under real environmental conditions over a year. More than 52% of the variance in the BBzP concentration was found to be associated with the covariance of the environmental factors. The air exchange rate contributed to 16% of the variance in the concentration. In addition, the indoor air temperature and relative humidity contributed 9% of the variance in the gas-phase concentration of BBzP and 7% of the variance in the settled dust concentration of BBzP. The variance in the concentration of the total suspended particles contributed 10% of the variance in the BBzP concentration on the walls and windows
Noncommutative Stein's maximal spherical means
Based on a proper hypothesis on the noncommutative Fourier integral
operators, we establish in this paper the strong-type (with ) estimates for the operator-valued Stein's maximal spherical
means
The effects of peculiar velocities on the morphological properties of large-scale structure
It is known that the large-scale structure (LSS) mapped by a galaxy redshift
survey is subject to distortions by galaxies' peculiar velocities. Besides the
signatures generated in common N-point statistics, such as the anisotropy in
the galaxy 2-point correlation function, the peculiar velocities also induce
distinct features in LSS's morphological properties, which are fully described
by four Minkowski functionals (MFs), i.e., the volume, surface area, integrated
mean curvature and Euler characteristic (or genus). In this work, by using
large suite of N-body simulations, we present and analyze these important
features in the MFs of LSS on both (quasi-)linear and non-linear scales, with a
focus on the latter. We also find the MFs can give competitive constraints on
cosmological parameters compared to the power spectrum, probablly due to the
non-linear information contained. For galaxy number density similar to the DESI
BGS galaxies, the constraint on from the MFs with one smoothing
scale can be better by than from the power spectrum. These findings
are important for the cosmological applications of MFs of LSS, and probablly
open up a new avenue for studying the peculiar velocity field itself.Comment: 6 pages, 3 figures, accepted by PR
Influence of secondary structure on kinetics and reaction mechanism of DNA hybridization
Hybridization of nucleic acids with secondary structure is involved in many biological processes and technological applications. To gain more insight into its mechanism, we have investigated the kinetics of DNA hybridization/denaturation via fluorescence resonance energy transfer (FRET) on perfectly matched and single-base-mismatched DNA strands. DNA hybridization shows non-Arrhenius behavior. At high temperature, the apparent activation energies of DNA hybridization are negative and independent of secondary structure. In contrast, when temperature decreases, the apparent activation energies of DNA hybridization change to positive and become structure dependent. The large unfavorable enthalpy of secondary structure melting is compensated for by concomitant duplex formation. Based on our results, we propose a reaction mechanism about how the melting of secondary structure influences the hybridization process. A significant point in the mechanism is that the rate-limiting step switches along with temperature variation in the hybridization process of structured DNA, because the free energy profile of hybridization in structured DNA varies with the variation in temperature
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Self-sustainable protonic ceramic electrochemical cells using a triple conducting electrode for hydrogen and power production.
The protonic ceramic electrochemical cell (PCEC) is an emerging and attractive technology that converts energy between power and hydrogen using solid oxide proton conductors at intermediate temperatures. To achieve efficient electrochemical hydrogen and power production with stable operation, highly robust and durable electrodes are urgently desired to facilitate water oxidation and oxygen reduction reactions, which are the critical steps for both electrolysis and fuel cell operation, especially at reduced temperatures. In this study, a triple conducting oxide of PrNi0.5Co0.5O3-δ perovskite is developed as an oxygen electrode, presenting superior electrochemical performance at 400~600 °C. More importantly, the self-sustainable and reversible operation is successfully demonstrated by converting the generated hydrogen in electrolysis mode to electricity without any hydrogen addition. The excellent electrocatalytic activity is attributed to the considerable proton conduction, as confirmed by hydrogen permeation experiment, remarkable hydration behavior and computations
Vasculogenic mimicry contributes to lymph node metastasis of laryngeal squamous cell carcinoma
<p>Abstract</p> <p>Background</p> <p>Survival of laryngeal squamous cell carcinoma (LSCC) patients has remained unchanged over recent years due to its uncontrolled recurrence and local lymph node metastasis. Vasculogenic mimicry (VM) is an alternative type of blood supplement related to more aggressive tumor biology and increased tumor-related mortality. This study aimed to investigate the unique role of VM in the progression of LSCC.</p> <p>Methods</p> <p>We reviewed clinical pathological data of 203 cases of LSCC both prospectively and retrospectively. VM and endothelium-dependent vessel (EDV) were detected by immunohistochemistry and double staining to compare their different clinical pathological significance in LSCC. Survival analyses were performed to assess their prognostic significance as well.</p> <p>Results</p> <p>Both VM and EDV existed in LSCC type of blood supply. VM is related to pTNM stage, lymph node metastasis and pathology grade. In contrust, EDV related to location, pTNM stage, T stage and distant metastasis. Univariate analysis showed VM, pTNM stage, T classification, nodal status, histopathological grade, tumor size, and radiotherapy to be related to overall survival (OS). While, VM, location, tumor size and radiotherapy were found to relate to disease free survival (DFS). Multivariate analysis indicated that VM, but not EDV, was an adverse predictor for both OS and DFS.</p> <p>Conclusions</p> <p>VM existed in LSCC. It contributed to the progression of LSCC by promoting lymph node metastasis. It is an independent predictors of a poor prognosis of LSCC.</p
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