753 research outputs found
Large scale distribution of total mass versus luminous matter from Baryon Acoustic Oscillations: First search in the SDSS-III BOSS Data Release 10
Baryon Acoustic Oscillations (BAOs) in the early Universe are predicted to
leave an as yet undetected signature on the relative clustering of total mass
versus luminous matter. A detection of this effect would provide an important
confirmation of the standard cosmological paradigm and constrain alternatives
to dark matter as well as non-standard fluctuations such as Compensated
Isocurvature Perturbations (CIPs). We conduct the first observational search
for this effect, by comparing the number-weighted and luminosity-weighted
correlation functions, using the SDSS-III BOSS Data Release 10 CMASS sample.
When including CIPs in our model, we formally obtain evidence at of
the relative clustering signature and a limit that matches the existing upper
limits on the amplitude of CIPs. However, various tests suggest that these
results are not yet robust, perhaps due to systematic biases in the data. The
method developed in this Letter, used with more accurate future data such as
that from DESI, is likely to confirm or disprove our preliminary evidence.Comment: 6 pages, 2 figures, accepted for publication in PR
Eficiência agronômica de fontes de fósforo associadas à inoculação com Pseudomonas fluorescens na produtividade de grãos do milho.
Visando a melhor eficiência agronômica relativa (EAR) do uso dos fertilizantes fosfatados, este estudo teve como objetivo avaliar o efeito de fontes de P associados à inoculação com Pseudomonas fluorescens via sementes na produtividade de grãos de plantas de milho. O experimento foi conduzido a campo, em esquema fatorial 6x2, em blocos casualizados, com quatro repetições. Foram aplicados 120 kg ha-1 de P via solo por meio de cinco fontes: Superfosfato Triplo (SFT), Gafsa, Itafós, SFT+Gafsa e SFT+Itafós, além do controle (sem P). As sementes foram submetidas a dois níveis de inoculação (com e sem) com Pseudomonas fluorescens da Estirpe 1008. Realizou-se a avaliação da EAR da produtividade de grãos. A inoculação de P. fluorescens no controle resultou em 87% de EAR. As aplicações de SFT+Itafós e SFT+Gafsa podem ser uma alternativa para os sistemas agrícolas, visando a menor utilização de fosfatos acidulados. O desempenho produtivo do milho não foi alterado pelas fontes de P e níveis de inoculação com P. fluorescens
Fontes de P associadas à inoculação de rizobactérias do gênero Pseudomonas no desenvolvimento de plantas de milho.
O estudo teve como objetivo avaliar o efeito de fosfatos solúveis e naturais associados à inoculação de rizobactérias do gênero Pseudomonas via sementes, no desenvolvimento de plantas de milho. O experimento foi conduzido em casa de vegetação, em esquema fatorial 6x3 em blocos casualizados, com quatro repetições. Foram aplicados 50 mg kg-1 de P via solo por meio de cinco fontes: Superfosfato Triplo (SFT), Fosfato Natural Gafsa, Fosfato Natural Itafós, SFT+Gafsa e SFT+Itafós (ambas as misturas na proporção 1:1), além do controle (sem P), associadas a três níveis de inoculação: sem inoculação, estirpe A (Burkholderia pickettii GN 2214) e a estirpe B (Pseudomonas sp. do grupo Fluorescente P21). Por ocasião do florescimento masculino (60 DAE) foram analisadas as seguintes características: massa seca de parte aérea (MSPA), massa seca de raiz (MSR), massa seca total (MST) e a relação raiz/parte aérea (MSR/MSPA). As plantas obtiveram os maiores crescimentos e desenvolvimentos com a aplicação de SFT. A combinação de SFT+Gafsa e SFT+Itafós proporcionaram maior desenvolvimento para MSPA, MSR, e MST em relação aos fosfatos naturais aplicados isoladamente. O controle apresentou a maior relação MSR/MSPA. As estirpes P21 e GN 2214 promovem a biomassa das plantas de milho. As combinações de fosfatos solúveis com naturais constituem uma nova opção para a correção fosfatada para os sistemas de produção agrícolas
IoT protocols, architectures, and applications
The proliferation of embedded systems, wireless technologies, and Internet protocols have made it possible for the Internet-of-things (IoT) to bridge the gap between the physical and the virtual world and thereby enabling monitoring and control of the physical environment by data processing systems. IoT refers to the inter-networking of everyday objects that are equipped with sensing, computing, and communication capabilities. These networks can collaborate to autonomously solve a variety of tasks. Due to the very diverse set of applications and application requirements, there is no single communication technology that is able to provide cost-effective and close to optimal performance in all scenarios. In this chapter, we report on research carried out on a selected number of IoT topics: low-power wide-area networks, in particular, LoRa and narrow-band IoT (NB-IoT); IP version 6 over IEEE 802.15.4 time-slotted channel hopping (6TiSCH); vehicular antenna design, integration, and processing; security aspects for vehicular networks; energy efficiency and harvesting for IoT systems; and software-defined networking/network functions virtualization for (SDN/NFV) IoT
Micromegas operation in high pressure xenon: charge and scintillation readout
The operational characteristics of a Micromegas operating in pure xenon at
the pressure range of 1 to 10 bar are investigated. The maximum charge gain
achieved in each pressure is approximately constant, around 4x10^2, for xenon
pressures up to 5 bar and decreasing slowly above this pressure down to values
somewhat above 10^2 at 10 bar. The MM presents the highest gains for xenon
pressures above 4 bar, when compared to other micropattern gaseous multipliers.
The lowest energy resolution obtained for X-rays of 22.1 keV exhibits a steady
increase with pressure, from 12% at 1bar to about 32% at 10 bar. The effective
scintillation yield, defined as the number of photons exiting through the MM
mesh holes per primary electron produced in the conversion region was
calculated. This yield is about 2x10^2 photons per primary electron at 1 bar,
increasing to about 6x10^2 at 5 bar and, then, decreasing again to 2x10^2 at 10
bar. The readout of this scintillation by a suitable photosensor will result in
higher gains but with increased statistical fluctuations.Comment: 22 pages, 11 figure
X-ray Linear Dichroism in cubic compounds: the case of Cr3+ in MgAl2O4
The angular dependence (x-ray linear dichroism) of the Cr K pre-edge in
MgAl2O4:Cr3+ spinel is measured by means of x-ray absorption near edge
structure spectroscopy (XANES) and compared to calculations based on density
functional theory (DFT) and ligand field multiplet theory (LFM). We also
present an efficient method, based on symmetry considerations, to compute the
dichroism of the cubic crystal starting from the dichroism of a single
substitutional site. DFT shows that the electric dipole transitions do not
contribute to the features visible in the pre-edge and provides a clear vision
of the assignment of the 1s-->3d transitions. However, DFT is unable to
reproduce quantitatively the angular dependence of the pre-edge, which is, on
the other side, well reproduced by LFM calculations. The most relevant factors
determining the dichroism of Cr K pre-edge are identified as the site
distortion and 3d-3d electronic repulsion. From this combined DFT, LFM approach
is concluded that when the pre-edge features are more intense than 4 % of the
edge jump, pure quadrupole transitions cannot explain alone the origin of the
pre-edge. Finally, the shape of the dichroic signal is more sensitive than the
isotropic spectrum to the trigonal distortion of the substitutional site. This
suggests the possibility to obtain quantitative information on site distortion
from the x-ray linear dichroism by performing angular dependent measurements on
single crystals
Эффективность процесса сушки масличных семян во взвешенном слое
The drying process of oilseeds in a suspended layer is investigated in order to increase productivity, reduce energy consumption and improve the quality of seeds for multipurpose use. To study the process of drying seeds of agricultural oilseeds, an experimental installation for drying seeds in a suspended layer has been developed, tested, optimized and implemented. The developed plant for drying seeds in a suspended layer is simple in design and easy to use, has high productivity. It also automates the process and has demonstrated a high level of operational safety during testing. To evaluate the effectiveness of the process of drying seeds in a suspended layer using the developed installation, three types of seeds of oilseed crops were selected: flax seeds, grapes and white sea buckthorn seeds. The results of the conducted studies of the drying process using the developed installation are: increasing the speed of the drying process; reducing the processing time; reducing energy consumption; reduction of processing costs; reduction of cost of processed products; improvement of the quality of processed products by increasing the degree of uniformity of drying and ensuring the preservation of the basic properties of seeds during heat treatment, mainly by reducing the degree of oxidation of vegetable fats in their components. Due to the rationalization of the drying process of oilseeds based on processing in a suspended layer, a number of tasks currently facing enterprises engaged in the primary processing of agricultural products have been solved. Using the results of the study will increase productivity, reduce energy consumption and processing costs, reduce the degree of oxidation of vegetable fats in the composition of seeds and improve their quality for subsequent use in the food industry, medicine, cosmetology, pharmaceuticals, etc.Исследован процесс сушки масличных семян во взвешенном слое с целью повышения производительности, снижения энергозатрат и повышения качества семян для их многоцелевого использования. Для изучения процесса сушки семян сельскохозяйственных масличных культур разработана, испытана, оптимизирована и внедрена экспериментальная установка для сушки семян во взвешенном слое. Разработанная установка для сушки семян во взвешенном слое проста по конструкции и удобна в применении, имеет высокую производительность. Она также позволяет автоматизировать процесс и продемонстрировала высокий уровень эксплуатационной безопасности во время испытаний. Чтобы оценить эффективность процесса сушки семян во взвешенном слое с применением разработанной установки были отобраны три вида семян масличных сельскохозяйственных культур: семена льна, винограда и облепихи белой. Результатами проведенных исследований процесса сушки с использованием разработанной установки являются: увеличение скорости процесса сушки; сокращение времени технологической обработки; снижение энергопотребления; снижение затрат на переработку; снижение себестоимости продуктов переработки; повышение качества продуктов переработки за счет повышения степени равномерности сушки и обеспечения сохранения основных свойств семян в процессе термической обработки, главным образом при снижении степени окисления растительных жиров в их компонентах. За счет рационализации процесса сушки масличных семян, основанной на обработке во взвешенном слое, решен ряд задач, стоящих в настоящее время перед предприятиями, которые заняты первичной переработкой сельскохозяйственной продукции. Использование результатов исследования позволит повысить производительность, уменьшить потребление электроэнергии и затраты на переработку, снизить степень окисления растительных жиров в составе семян и повысить их качество для последующего применения в пищевой промышленности, медицине, косметологии, фармацевтике и т.д
Did Ebola emerge in West Africa by a policy-driven phase change in agroecology? Ebola's social context
SCOPUS: no.jinfo:eu-repo/semantics/publishe
Study of the transient nature of classical Be stars using multi-epoch optical spectroscopy
Variability is a commonly observed property of classical Be stars (CBe)
stars. In extreme cases, complete disappearance of the H{\alpha} emission line
occurs, indicating a disc-less state in CBe stars. The disc-loss and
reappearing phases can be identified by studying the H{\alpha} line profiles of
CBe stars on a regular basis. In this paper, we present the study of a set of
selected 9 bright CBe stars, in the wavelength range of 6200 - 6700 {\AA}, to
better understand their disc transient nature through continuous monitoring of
their H{\alpha} line profile variations for 5 consecutive years (2015 -- 2019).
Based on our observations, we suggest that 4 of the program stars (HD 4180, HD
142926, HD 164447 and HD 171780) are possibly undergoing disc-loss episodes,
whereas one other star (HD 23302) might be passing through disc formation
phase. The remaining 4 stars (HD 237056, HD 33357, HD 38708 and HD 60855) have
shown signs of hosting a stable disc in recent epochs. Through visual
inspection of the overall variation observed in the H{\alpha} EW for these
stars, we classified them into groups of growing, stable and dissipating discs,
respectively. Moreover, our comparative analysis using the BeSS database points
out that the star HD 60855 has passed through a disc-less episode in 2008, with
its disc formation happening probably over a timescale of only 2 months,
between January and March 2008.Comment: 19 pages, 7 figures, 2 tables, accepted in JAp
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