Heterostructures based on layering of two-dimensional (2D) materials such as graphene and hexagonal boron nitride represent a new class of electronic devices. Realizing this potential, however, ...depends critically on the ability to make high-quality electrical contact. Here, we report a contact geometry in which we metalize only the ID edge of a 2D graphene layer. In addition to outperforming conventional surface contacts, the edge-contact geometry allows a complete separation of the layer assembly and contact metallization processes. In graphene heterostructures, this enables high electronic performance, including low-temperature ballistic transport over distances longer than 15 micrometers, and room-temperature mobility comparable to the theoretical phonon-scattering limit. The edge-contact geometry provides new design possibilities for multilayered structures of complimentary 2D materials.
HELP: the Herschel Extragalactic Legacy Project Shirley, R; Duncan, K; Campos Varillas, M C ...
Monthly notices of the Royal Astronomical Society,
10/2021, Volume:
507, Issue:
1
Journal Article
Peer reviewed
Open access
ABSTRACT
We present the Herschel Extragalactic Legacy Project (HELP). This project collates, curates, homogenizes, and creates derived data products for most of the premium multiwavelength ...extragalactic data sets. The sky boundaries for the first data release cover 1270 deg2 defined by the Herschel SPIRE extragalactic survey fields; notably the Herschel Multi-tiered Extragalactic Survey (HerMES) and the Herschel Atlas survey (H-ATLAS). Here, we describe the motivation and principal elements in the design of the project. Guiding principles are transparent or ‘open’ methodologies with care for reproducibility and identification of provenance. A key element of the design focuses around the homogenization of calibration, meta data, and the provision of information required to define the selection of the data for statistical analysis. We apply probabilistic methods that extract information directly from the images at long wavelengths, exploiting the prior information available at shorter wavelengths and providing full posterior distributions rather than maximum-likelihood estimates and associated uncertainties as in traditional catalogues. With this project definition paper, we provide full access to the first data release of HELP; Data Release 1 (DR1), including a monolithic map of the largest SPIRE extragalactic field at 385 deg2 and 18 million measurements of PACS and SPIRE fluxes. We also provide tools to access and analyse the full HELP data base. This new data set includes far-infrared photometry, photometric redshifts, and derived physical properties estimated from modelling the spectral energy distributions over the full HELP sky. All the software and data presented is publicly available.
ABSTRACT
We report on precise Doppler measurements of L231-32 (TOI-270), a nearby M dwarf (d = 22 pc, M⋆ = 0.39 M⊙, R⋆ = 0.38 R⊙), which hosts three transiting planets that were recently discovered ...using data from the Transiting Exoplanet Survey Satellite (TESS). The three planets are 1.2, 2.4, and 2.1 times the size of Earth and have orbital periods of 3.4, 5.7, and 11.4 d. We obtained 29 high-resolution optical spectra with the newly commissioned Echelle Spectrograph for Rocky Exoplanet and Stable Spectroscopic Observations (ESPRESSO) and 58 spectra using the High Accuracy Radial velocity Planet Searcher (HARPS). From these observations, we find the masses of the planets to be 1.58 ± 0.26, 6.15 ± 0.37, and 4.78 ± 0.43 M⊕, respectively. The combination of radius and mass measurements suggests that the innermost planet has a rocky composition similar to that of Earth, while the outer two planets have lower densities. Thus, the inner planet and the outer planets are on opposite sides of the ‘radius valley’ – a region in the radius-period diagram with relatively few members – which has been interpreted as a consequence of atmospheric photoevaporation. We place these findings into the context of other small close-in planets orbiting M dwarf stars, and use support vector machines to determine the location and slope of the M dwarf (Teff < 4000 K) radius valley as a function of orbital period. We compare the location of the M dwarf radius valley to the radius valley observed for FGK stars, and find that its location is a good match to photoevaporation and core-powered mass-loss models. Finally, we show that planets below the M dwarf radius valley have compositions consistent with stripped rocky cores, whereas most planets above have a lower density consistent with the presence of a H-He atmosphere.
The replacement of fish meal (FM) by increasing levels of plant protein (PP) sources 50% (PP50), 75% (PP75) and 100% (PP100) was compared to a control diet (FM) containing fish meal as the main ...protein source in ongrowing Senegalese sole (mean initial body weight:106g±15). These four diets were isonitrogenous and isolipidic (54% crude protein and 9% crude fat on a dry matter basis). By the end of the growth trial, groups fed PP50 and PP75 had a final body weight and daily growth index (DGI) similar to the FM fed group (200g and 0.8–0.9, respectively), whereas PP100 diet induced a significantly lower DGI (0.4). PP100 showed the highest feed conversion ratio (FCR) (2.4 vs 1.5) and the lowest protein gain (0.5 vs 0.9gkg−1ABWday−1). Nutrient intake of PP groups was statistically similar to the FM group. Apparent digestibility coefficients (ADCs) of nutrients did not differ significantly among treatments (p>0.05) and all PP diets induced lower fecal P losses than the FM group (33%).
The highest PP levels (PP75 and PP100) resulted in decreased whole body lipid contents, thought PP100 showed the highest HSI and liver total lipids. In all groups, liver was the major lipid storage organ (13.96–28.57% WW). Muscle lipid content was low (1.3–1.6% WW) and did not vary significantly among treatments. Polyunsaturated fatty acid (PUFA) levels in muscle were also similar amongst dietary treatments and the two highest replacement levels (PP75 and PP100) were still effective in producing an n-3 PUFA rich product (29–30% of total fatty acids (WW)) similar to the FM group (33% of total fatty acids (WW)). Docosahexaenoic acid (DHA) was selectively retained in muscle (17–21% of total fatty acids (WW)) and neither DHA/EPA (Eicosapentaenoic acid) nor EPA/ARA (Arachidonic acid) ratios were significantly affected (p>0.05) by dietary treatments. The sensory evaluation of cooked slices showed that the replacement of marine protein sources (FM) by PP blends did not have a significant impact on the majority of the descriptors, though visual freshness and whiteness of the PP75 flesh yielded the highest scores.
Our results indicate that ongrowing Senegalese sole can effectively use diets with high levels of PP sources, up to 75% of FM replacement, without impairing feed intake, growth performance and protein utilisation whilst preserving high n−3 PUFA and DHA flesh content.
► High levels of plant protein (PP) blends were tested (50–75–100%) in ongrowing fish. ► Senegalese sole can use diets with PP sources up to 75% of fish meal replacement. ► Apparent digestibility coefficients of nutrients was similar among treatments. ► PP blends preserve high n-3 PUFA and DHA flesh content. ► PP diets did not affect the majority of sensorial descriptors of cooked slices.
Nuclear proliferation marker MIB-1 (Ki-67) immunohistochemistry (IHC) is used to examine tumor cell proliferation. However, the diagnostic or prognostic value of the Ki-67 nuclear staining intensity ...and location, defined as nuclear gradient (NG), has not been assessed. This study examined the potential association between Ki-67 NG and cell cycle phases and its effect on the prognosis of pulmonary typical carcinoid (PTC) tumors. We propose a method for classifying the NG of Ki-67 during the cell cycle and compare the results between PTC, pulmonary adenocarcinoma (PAD), and breast ductal carcinoma (BDC). A literature review and objective analysis of IHC-stained paraffin sections were used to determine the Ki-67 labeling index and composed a stratification of the NG into NG1, NG2, and NG3/4 categories. A semi- automated image analysis protocol was established to determine the Ki-67 NG in PTC, PAD, and BDC. High intraobserver consistency and moderate interobserver agreement were achieved in the determination of Ki-67 NG in tumor specimens. NG1 and NG2 were lower in PTC than in PAD and BDC. Cox multivariate analysis of PTC after adjusting for age and number of metastatic lymph nodes showed that Ki- 67 NG1 and NG2 significantly predicted clinical outcomes. The semi-automated method for quantification of Ki-67 nuclear immunostaining proposed in this study could become a valuable diagnostic and prognostic tool in PTC. Key words: Pulmonary typical carcinoid tumor; Chromatin gradient; Cell cycle; Image analysis; Prognosis
Subtropical ocean gyres play a key role in modulating the global climate system redistributing energy between low and high latitudes. A poleward displacement of the subtropical gyres has been ...observed over the last decades, but the lack of long-term monitoring data hinders an in-depth understanding of their dynamics. Paleoceanographic records offer the opportunity to identify meridional changes in the subtropical gyres and investigate their consequences to the climate system. Here we use the abundance of planktonic foraminiferal species Globorotalia truncatulinodes from a sediment core collected at the northernmost boundary of the South Atlantic Subtropical Gyre (SASG) together with a previously published record of the same species from the southernmost boundary of the SASG to reconstruct meridional fluctuations of the SASG over last ca. 70 kyr. Our findings indicate southward displacements of the SASG during Heinrich Stadials (HS) 6-4 and HS1, and a contraction of the SASG during HS3 and HS2. During HS6-4 and HS1, the SASG southward displacements likely boosted the transfer of heat to the Southern Ocean, ultimately strengthening deep-water upwelling and CO
release to the atmosphere. We hypothesize that the ongoing SASG poleward displacement may further increase oceanic CO
release.
The continuous research and development regarding firefighters’ personal protective equipment (PPE) has led to significant improvements in recent decades. Despite the evolution of firefighters’ PPE, ...every year an undesirable number of firefighters are seriously burned during firefighting operations, with some of them eventually losing their lives. The protection given by firefighters’ PPE can be further increased with the incorporation of smart textiles in the personal protective equipment, namely, wearable electronics (i.e., integrated sensors to monitor diverse parameters: heart rate, oxygen saturation, carbon dioxide detector, and setting real-time communication with a command post) and advanced materials such as phase change materials (PCMs). The evolution of firefighters’ PPE has been followed by an evolution and update in the international and national standards that specify performance requirements for firefighters’ protective clothing for structural and wildland firefighting as well as technical rescue. This study will focus on the analysis of firefighters protective clothing evolution regarding the use and integration of advanced smart materials, namely, phase change materials, taking into consideration the evolution and requirements of international and European standards as well as national legislation for firefighters’ protective clothing.
Summary
Accurately quantifying the social distancing (SD) practice of a population is essential for governments and health agencies to better plan and adapt restrictions during a pandemic crisis. In ...such a scenario, the reduction of social mobility also has a significant impact on electricity consumption, since people are encouraged to stay at home and many commercial and industrial activities are reduced or even halted. This paper proposes a methodology to qualify the SD of a medium‐sized city, located in the northwest of the state of Rio Grande do Sul (RS), Brazil, using data of electricity consumption measured by the municipality's energy utility. The methodology consists of combining a data set, and an average consumption profile of Sundays is obtained using data from 4‐months, it is then defined as a high SD profile due to the typical lower social activities on Sundays. An supervised and an unsupervised artificial neural network (ANN) are trained with this profile and used to analyze electricity consumption of this city during the COVID‐19 pandemic. Low, moderate, and high SD ranges are also created, and the daily population behavior is evaluated by the ANNs. The results are strongly correlated and discussed with government restrictions imposed during the analyzed period and indicate that the ANNs can correctly classify the intensity of SD practiced by people. The unsupervised ANN is used more easily and in different scenarios, so it can be indicated for use by public administration for purposes of assess the effectiveness of SD policies based on the guidelines established during the COVID‐19 pandemic.
Considering the high level of heat and flame exposure firefighters encounter while performing their work activities, personal protective equipment (PPE) is of the utmost importance to enhance their ...safety. Phase change materials (PCMs) are known as advanced materials able to absorb high amounts of thermal energy, with the potential to increase the thermal performance of protective clothing. In this work, a PCM-vest was developed for the first time, and its thermal performance was evaluated. A three-stage approach was followed: (1) at a small scale in the laboratory, the effect of different encapsulated PCMs on a multilayer assembly performance was evaluated; (2) in the laboratory, the essential requirements of heat and flame tests were assessed; and (3) in a simulated urban fire, the thermal performance of three different PCM-vests (different textiles and designs) was studied. As the main conclusions, the PCMs significantly affected the heating rate of the multilayer assembly, particularly when a PCM with higher latent heat was used. In some cases, the heat transfer index (HTI) doubled by comparison with the sample without PCMs. As a drawback and as expected, the cooling time was increased. The PCM-vest sample ensured the requirements of the heat and flame tests. Through this study, the positive impact of using PCMs to enhance the heat protection of conventional PPE can be highlighted.
•For the first time, a biomass approach was used to investigate backwashed SSF.•Biomass accumulated differently in scraped and backwashed slow sand filters.•16S rRNA sequencing indicated variation of ...the bacterial community between filters.•Biomass was better preserved in different trophic levels after backwash.•The filtrate was of good quality in BFS and ScSF despite their biomass differences.
Biomass was assessed as a new approach for evaluating backwashed slow sand filters (BSF). Slow sand filtration (SSF) is a simple technology for water treatment, where biological mechanisms play a key role in filtration efficiency. Backwashed slow sand filters were previously recommended for small-scale filters (~1 m² of filtration area) as an alternative to conventional filters that are usually cleaned by scraping (ScSF). Biomass was never evaluated in BSF, which is a gap in the knowledge of this technology, considering the importance of its biological mechanisms. Therefore, for the first time, two filters operating under the same conditions were used to compare the influence of backwashing on biomass; one filter was cleaned by backwashing and the other by scraping. Biomass along the filter media depth (40 cm) was assessed by different techniques and compared in terms of cellular biomass (by chloroform fumigation), volatile solids, bacterial community (by 16S rRNA gene sequencing), and observations by scanning electron and fluorescence microscopy. Filters were also monitored and compared regarding filtered water quality and headloss; their differences were related to the different cleaning processes. Overall, filtered water quality was acceptable for slow sand filter standards (turbidity < 1 NTU and total coliform removal > 1 log). However, headloss developed faster on scraped filters, and biomass was different between the two filters. Backwashing did not significantly disturb biomass while scraping changed its surface sand layers. Cell biomass was more abundant and spread across the filtration depth, related to lower headloss, turbidity, and cyanobacterial breakthrough. These results agreed with the water quality and microscopy observations. The bacterial community was also less stratified in the backwashed filter media. These results expand the knowledge of backwashing use in slow sand filters, demonstrating that this process preserves more biomass than scraping. In addition, biomass preservation can lead to bacterial selectivity and faster filter ripening. Considering the importance of biomass preservation on slow sand filtration and its biological filtration mechanisms, the results presented in this paper are promising. The novel insight that BSF can preserve biomass after backwashing may contribute to increasing its application in small communities.
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