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6,175 results for “Composite”
Diversity and composition of macroinvertebrate communities in a rare inland salt marsh
<p>Inland salt marshes are rare habitats in the Great Lakes region of North America, formed on salt deposits from the Silurian period. These patchy habitats are abiotically stressful for the freshwater invertebrates that live there, and provide an opportunity to study the relationship between stress and diversity. We used morphological and COI metabarcoding data to assess changes in diversity and composition across both space (a transect from the salt seep to an adjacent freshwater area) and time (three sampling seasons). Richness was significantly lower at the seep site with both datatypes, while metabarcoding data additionally showed reduced richness at the freshwater transect end, consistent with a pattern where intermediate levels of stress show higher diversity. We found complementary, rather than redundant, patterns of community composition using the two datatypes: not all taxa were equally sequenced with the metabarcoding protocol. We identified taxa that are abundant at the salt seep of the marsh, including biting midges (<i>Culicoides</i>) and ostracods (<i>Heterocypris</i>). We conclude that (as found in other studies) molecular and morphological work should be used in tandem to identify the biodiversity in this rare habitat. Additionally, salinity may be a driver of community membership in this system, though further ecological research is needed to rule out alternate hypotheses.</p>
Structure of single-walled carbon nanotube reinforced polymer matrix composites
<p><strong>Structure of single-walled carbon nanotube reinforced polymer matrix composites</strong></p> <p>Junjie Chen</p> <p>Department of Energy and Power Engineering, School of Mechanical and Power Engineering, Henan Polytechnic University, 2000 Century Avenue, Jiaozuo, Henan, 454000, P.R. China</p> <p>Contributor: Junjie Chen, ORCID: 0000-0002-5022-6863, E-mail address: koncjj@gmail.com</p> <p> </p> <p>A composite material, also called a composite, is a solid material that results when two or more different substances, each with its own characteristics, are combined to create a new substance whose properties are superior to those of the original components in a specific application. The term composite more specifically refers to a structural material within which a fibrous material is embedded. The remarkable properties of composites are achieved by embedding fibers of one substance in a host matrix of another. In materials science, a polymer matrix composite is a composite material composed of a variety of short or continuous fibers bound together by a matrix of organic polymers. Polymer matrix composites are designed to transfer loads between fibers of a matrix. Some of the advantages with polymer matrix composites include their light weight, high resistance to abrasion and corrosion, and high stiffness and strength along the direction of their reinforcements. The function of the matrix in polymer matrix composites is to bond the fibers together and transfer loads between them. Polymer matrix composites matrices are typically either thermosets or thermoplastics. Thermosets are by far the predominant type in use today. Thermosets are subdivided into several resin systems including epoxies, phenolics, polyurethanes, and polyimides. Of these, epoxy systems currently dominate the advanced composite industry. Unlike fiber-reinforced polymer matrix composites, nanomaterials reinforced polymer matrix composites are able to achieve significant improvements in mechanical properties at much lower loadings. Carbon nanotubes in particular have been intensely studied due to their exceptional intrinsic mechanical properties and low densities. In particular carbon nanotubes have some of the highest measured tensile stiffnesses and strengths of any material due to the strong covalent bonds between carbon atoms. However, in order to take advantage of the exceptional mechanical properties of the nanotubes, the load transfer between the nanotubes and matrix must be very large. Like in fiber-reinforced composites, the size dispersion of the carbon nanotubes significantly affects the final properties of the composite. Long carbon nanotubes lead to an increase in tensile stiffness and strength due to the large-distance stress transfer and crack propagation prevention. On the other hand, short carbon nanotubes do not lead to any enhancement of properties without any interfacial adhesion. However once modified, short carbon nanotubes are able to further improve the stiffness of the composite, however there is still very little crack propagation countering. In general, long and high aspect ratio carbon nanotubes lead to greater enhancement of mechanical properties, but are more difficult to process. Aside from size, the interface between the carbon nanotubes and the polymer matrix is of exceptional importance. In order to achieve better load transfer, a number of different methods have been used to better bond the carbon nanotubes to the matrix by functionalizing the surface of the carbon nanotube with various polymers. These methods can be divided into non-covalent and covalent strategies. Non-covalent carbon nanotube modification involves the adsorption or wrapping of polymers to the carbon nanotube surface, usually via van der Waal's or π-stacking interactions. In contrast, covalent functionalization involves direct bonding onto the carbon nanotube. This can be achieved in a number of ways, such as oxidizing the surface of the carbon nanotube and reacting with the oxygenated site, or using a free radical to directly react with the carbon nanotube lattice. Covalent functionalization can be used to directly attach the polymer to the carbon nanotube, or to add an initiator molecule which can then be used for further reactions.</p>
Fluid mechanics of carbon nanotube reinforced polymer composites
<p><strong>Fluid mechanics of carbon nanotube reinforced polymer composites</strong></p> <p>Junjie Chen</p> <p>Department of Energy and Power Engineering, School of Mechanical and Power Engineering, Henan Polytechnic University, 2000 Century Avenue, Jiaozuo, Henan, 454000, P.R. China</p> <p>Contributor: Junjie Chen, ORCID: 0000-0002-5022-6863, E-mail address: koncjj@gmail.com</p> <p> </p> <p>Fluid mechanics is the science concerned with the response of fluids to forces exerted upon them. It is a branch of classical physics with applications of great importance in hydraulic and aeronautical engineering and chemical engineering. Fluid mechanics is a subject with almost endless ramifications, and the account that follows is necessarily incomplete. Some knowledge of the basic properties of fluids will be needed. Fluids are not strictly continuous media in the way that all the successors of Euler and Bernoulli have assumed, for they are composed of discrete molecules. The molecules, however, are so small and, except in gases at very low pressures, the number of molecules per milliliter is so enormous that they need not be viewed as individual entities. There are a few liquids, known as liquid crystals, in which the molecules are packed together in such a way as to make the properties of the medium locally anisotropic, but the vast majority of fluids are isotropic. In fluid mechanics, the state of an isotropic fluid may be completely described by defining its mean mass per unit volume, or density, its temperature, and its velocity at every point in space, and just what the connection is between these macroscopic properties and the positions and velocities of individual molecules is of no direct relevance. A number of phenomena of considerable physical interest can be discussed using little more than the law of conservation of energy. However, the argument has so far been restricted to cases of steady flow. To discuss cases in which the flow is not steady, an equation of motion for fluids is needed, and one cannot write down a realistic equation of motion without facing up to the problems presented by viscosity, which have so far been deliberately set aside. Thermodynamics is the science of the relationship between heat, work, temperature, and energy. In broad terms, thermodynamics deals with the transfer of energy from one place to another and from one form to another. The key concept is that heat is a form of energy corresponding to a definite amount of mechanical work. Although thermodynamics developed rapidly during the 19th century in response to the need to optimize the performance of steam engines, the sweeping generality of the laws of thermodynamics makes them applicable to all physical systems. In particular, the laws of thermodynamics give a complete description of all changes in the energy state of any system and its ability to perform useful work on its surroundings. Classical thermodynamics does not involve the consideration of individual atoms or molecules. Such concerns are the focus of the branch of thermodynamics known as statistical thermodynamics, or statistical mechanics, which expresses macroscopic thermodynamic properties in terms of the behavior of individual particles and their interactions. It has its roots in the latter part of the 19th century, when atomic and molecular theories of matter began to be generally accepted. The application of thermodynamic principles begins by defining a system that is in some sense distinct from its surroundings. In general, systems are free to exchange heat, work, and other forms of energy with their surroundings. A particularly important concept is thermodynamic equilibrium, in which there is no tendency for the state of a system to change spontaneously. For example, the gas in a cylinder with a movable piston will be at equilibrium if the temperature and pressure inside are uniform and if the restraining force on the piston is just sufficient to keep it from moving. The system can then be made to change to a new state only by an externally imposed change in one of the state functions, such as the temperature by adding heat or the volume by moving the piston. A sequence of one or more such steps connecting different states of the system is called a process.</p>
Composition and electrical resistance results of a Ir-Pd-Pt-Rh-Ru composition spread thin film materials library
<p>The dataset contains the results of electrical resistance measurement and composition analysis of a thin film composition spread materials library. </p> <p>342 measurement areas were evaluated for chemical composition using energy dispersive X-ray spectroscopy and electrical resistance using a 4-point probe.</p> <p>CSV columns:</p> <p>x: x-coordinate of materials library in µm</p> <p>y: y-coordinate of materials library in µm</p> <p>Ir: relative chemical composition in at.%</p> <p>Pd: relative chemical composition in at.%</p> <p>Pt: relative chemical composition in at.%</p> <p>Rh: relative chemical composition in at.%</p> <p>Ru: relative chemical composition in at.%</p> <p>Resistance: electrical resistance in Ohm</p> <p> </p> <p>This dataset is supplementary information for an associated publication. A link to the publication will be provided after publishing.</p>
The SICK (Sentences Involving Compositional Knowledge) dataset for relatedness and entailment
<p>The SICK data set consists of about 10,000 English sentence pairs, generated starting from two existing sets: the <a href="http://nlp.cs.illinois.edu/HockenmaierGroup/data.html">8K ImageFlickr data set</a> and the <a href="http://www.cs.york.ac.uk/semeval-2012/task6/index.php?id=data">SemEval 2012 STS MSR-Video Description data set</a>. We randomly selected a subset of sentence pairs from each of these sources and we applied a 3-step generation process: first, the original sentences were normalized to remove unwanted linguistic phenomena; the normalized sentences were then expanded to obtain up to three new sentences with specific characteristics suitable to CDSM evaluation; as a last step, all the sentences generated in the expansion phase were paired with the normalized sentences in order to obtain the final data set.</p> <p>Each sentence pair was annotated for relatedness and entailment by means of crowdsourcing techniques. The <strong>sentence relatedness score</strong> (on a 5-point rating scale) provides a direct way to evaluate CDSMs, insofar as their outputs are meant to quantify the degree of semantic relatedness between sentences; the categorizations in terms of the <strong>entailment relation between the two sentences</strong> (with <em>entailment, contradiction</em>, and <em>neutral</em> as gold labels) is also a crucial aspect to consider, since detecting the presence of entailment is one of the traditional benchmarks of a successful semantic system.</p> <p>In the final set, gold scores for relatedness and entailment were distributed as follows: the relatednes scoring resulted in 923 pairs within the [1,2) range, 1373 pairs within the [2,3) range, 3872 pairs within the [3,4) range, and 3672 pairs within the [4,5] range; the entailment annotation led to 5595 <em>neutral</em> pairs, 1424 <em>contradiction</em> pairs, and 2821 <em>entailment</em> pairs.</p> <p><strong>Files</strong></p> <ul> <li>SICK.zip (main file)</li> <li>SICK_Annotated.zip (a version of the data set annotated for the expansion rule which was used in each case)</li> <li>SICK_subsets.zip (a Indexes specifying further classifications, used in the JLRE 2016 publication)</li> </ul> <p> </p>
Data archive: Trophic structure of cold-water coral communities revealed from the analysis of tissue isotopes and fatty acid composition
<p>Data belonging to the paper: </p> <p>Dick van Oevelen, Gerard C. A. Duineveld, Marc S. S. Lavaleye, Tina Kutti and Karline Soetaert (2017) Trophic structure of cold-water coral communities revealed from the analysis of 55 tissue isotopes and fatty acid composition. Marine Biology Research, DOI: https://doi.org/10.1080/17451000.2017.1398404</p> <p>Abstract:</p> <p>The trophic structure of cold-water coral reef communities at two contrasting locations, the 800-<br> m deep Belgica Mounds (Irish margin) and 300-m deep Træna reefs (Norwegian Shelf), was<br> investigated using stable isotope (δ13C and δ15N) and fatty-acid composition analysis. A<br> broad range of specimens, with emphasis on (commercial) fish species, and organic matter<br> sources were sampled using a variety of tools. Irrespective of the environmental and<br> geographical setting, the δ15N values indicated that the food web encompasses roughly 1.5<br> to 3 trophic levels. Mobile echinoderms, i.e. sea urchins and sea stars, had highest δ15N<br> values, indicative of a high trophic position in the food web. The fraction of bacterial fatty<br> acids in reef fauna was generally low (<5%), indicating that enhanced bacterial production in<br> the water column through seafloor seepage of nutrients (‘hydraulic theory’) does not form a<br> significant energy pathway into the food web. The high fraction of algal and essential fatty<br> acids in reef fauna and fish at both locations indicates a close coupling with surface<br> productivity, but the transport mechanism depends on the hydrographic setting. At Træna,<br> Calanus copepods and euphausiids form an additional link between primary production and<br> fish, which is largely absent at Belgica Mounds. At Belgica Mounds, the reef community is<br> primarily supported by phytodetritus, as evidenced by the high contribution of algal fatty<br> acids in faunal tissue and seasonal chlorophyll a deposition and marine snow at the reef. The<br> environmental setting of cold-water coral reefs influences the structure of the associated<br> food web.</p>
General database of O2/CO2 and H20 permeability for polymer-based nano composites
<p>More than 1000 values (i.e. about 170 articles) of the 1995-2015 period containing measured values of O2, CO2 and H2O permeability in polymer-based nanocomposites were collected from the available literature and capitalized in this dedicated on-line database. These data were assorted and compared in order to decipher the role of particle shape (either iso-dimensional, elongated or platelets nanoparticles) on the reduction of the relative permeability of the nano composite. The proposed on-line database consists in the first and unprecedented compilation of permeability values for nanocomposite based materials.</p>
Figure 1: Abstract Meta-Model-UNDERSTANDING SERVICE COMPOSITION WITH NON-FUNCTIONAL PROPERTIES USING DECLARATIVE MODEL-TO-MODEL TRANSFORMATIONS
<p>To de¯ne the model we ¯rst de¯ned the abstract meta-model which con-<br> tains all the processes which can be used in the application model. These are<br> used to model the behaviour of the application (see Figure 1).</p>
Figure 4: Spectro°uorimetric spectra of TiO2/CdS composites samples with a di®erent mass proportion-PREPARATION AND CHARACTERIZATION OF TIO2/CDS LAYERS AS POTENTIAL PHOTOELECTROCATALYTIC MATERIALS
<p>Fig. 4 illustrates the fluorescence emission spectra of TiO2/CdS nanostructured ¯lm at the exciting<br> wavelength of 340 nm. The curves for TC 1, TC 2, TC 3 and TC 4 exhibited<br> the clear photoemission peaks at about 375 nm, and compared with emission of<br> bulk CdS (520 nm), 145 nm of blue shift was observed. These features indicate<br> the quantum-con¯ned e®ect of the TiO2/CdS nanocomposite ¯lms [25].</p>
PREPARATION AND CHARACTERIZATION OF TIO2/CDS LAYERS AS POTENTIAL PHOTOELECTROCATALYTIC MATERIALS-Figure 2: The FT/IR microscopy images of the TiO2/CdS composites
<p>The microstructural properties of the deposited TiO2/CdS layers depend<br> on the mass proportions of TiO2:CdS. The proportion of CdS phase is di-<br> rect proportional with the CdS powder used in the preparation process. The<br> FT/IR microscopy images of the TiO2/CdS composites upon annealing at high<br> temperatures, are shown in Fig.2<br> The micrograph shows agglomerates with irregular morphology and size<br> ranging from few micrometers down to hundreds of nanometer.</p>
Figure 1: X-ray di®raction pattern for TiO2/CdS composites samples-PREPARATION AND CHARACTERIZATION OF TIO2/CDS LAYERS AS POTENTIAL PHOTOELECTROCATALYTIC MATERIALS
<p>Fig. 1 shows the X-ray di®raction pattern for TiO2/CdS<br> composites (sample TC 1, TC 2, TC 3 and TC 4). The di®raction pattern of<br> the TiO2/CdS composites exhibits the di®raction peaks owning to CdS phase<br> (hexagonal and cubic). TiO2 (rutile and anatase) phases were also detected.</p>
Figure 3: Absorption spectra of TiO2/CdS composites samples with a di®erent mass proportion-PREPARATION AND CHARACTERIZATION OF TIO2/CDS LAYERS AS POTENTIAL PHOTOELECTROCATALYTIC MATERIALS
<p>Optical properties of TiO2/CdS semi-<br> conductor composites have been investigated using optical absorption and pho-<br> toluminescence spectroscopy. UV-VIS absorption spectra of the as-prepared<br> photocatalysts were taken on a JASCO V-550 spectrometer. The °uorescence<br> spectra were obtained using an ABL&Jasco V 6500 spectro°uorimeter with<br> xenon lamp. The optical studies of the TiO2/CdS composites were performed<br> using the absorption spectra observed in the wavelength range 200-900 nm.<br> Fig. 3 shows the UV-Vis spectra of TiO2/CdS samples.</p>
Dataset for 'Different in the dark: The effect of habitat characteristics on community composition and beta diversity in bromeliad microfauna'
<p>The file contains counting data for bromeliad-inhabiting microfauna (including, heterotrophic nanoflagellates, ciliates, amoeba and rotifers) from samples taken on Ilha do Cardoso, Brazil.</p> <p>Also included are additional Information on abiotic and biotic factors measured (e.g. pH, dissolved oxygen concentration etc.).</p>
Composite of graphene and silver nanoparticles obtained by low-dose gamma irradiation
<p>Content:</p> <p>TEM.zip - TEM images of composites, file type .tif and .dm3</p> <p>VINCA_FTIR.zip - FTIR data of graphene oxide and exfoliated graphene, file type .csv</p> <p>VINCA_UV-Vis.zip - FTIR data of graphene oxide and exfoliated graphene composites, file type .csv</p> <p>IEMN_VNA_Graphene-AgNP - EMI shielding measurement of graphene oxide and exfoliated graphene composites, file type .xlsx</p> <p>VINCA_CA_graphene-AgNP.jpg - contact angle measurement of graphene oxide and exfoliated graphene composites</p> <p>VINCA_532nmLASER.zip - temperature elevation measurements of graphene oxide and exfoliated graphene composites, file type .csv</p> <p>FTPO_TGA_Graphene-AgNP.zip - TGA data of graphene oxide and exfoliated graphene composites, file type .txt</p> <p> </p> <p> </p>
Data for "Sintering activation energies of anisotropic layered and particle alumina/zirconia-based composites and their mechanical response"
<p>The dataset contains several folders that provide open data files for the manuscript "Sintering activation energies of anisotropic layered and particle alumina/zirconia-based composites and their mechanical response".</p>
Рис. 2. Распределение Значений биомассы и численности Macoma balthica по станциЯм отбора проб. Fig. 2. Distribution of the Macoma balthica biomass and abundance values at sampling stations. in Species composition and distribution of bivalve mollusks in plankton and benthos in Nevelsky Strait in summer
Рис. 2. Распределение Значений биомассы и численности Macoma balthica по станциЯм отбора проб. Fig. 2. Distribution of the Macoma balthica biomass and abundance values at sampling stations.
Рис. 4. Распределение станций отбора проб по глубине и типу грунта (круЖком обведены станции, на которых макробентос не обнаруЖен; БО – биогенные остатки, ГМ – галька мелкаЯ, Гр – гравий, И – ил, П – песок). Fig. 4. Distribution of sampling stations by depth and type of bottom sediments (circles are around the stations where no macrobenthos was detected; БО – biogenic residues, ГМ – pebbles, Гр – gravel, И – silt, П – sand). in Species composition and distribution of bivalve mollusks in plankton and benthos in Nevelsky Strait in summer
Рис. 4. Распределение станций отбора проб по глубине и типу грунта (круЖком обведены станции, на которых макробентос не обнаруЖен; БО – биогенные остатки, ГМ – галька мелкаЯ, Гр – гравий, И – ил, П – песок). Fig. 4. Distribution of sampling stations by depth and type of bottom sediments (circles are around the stations where no macrobenthos was detected; БО – biogenic residues, ГМ – pebbles, Гр – gravel, И – silt, П – sand).
Рис. 5. АналиЗ линейной коррелЯции параметров макробентоса от доминируюЩей фракции в пробе грунта (А, Б) и глубины (В, Г). Fig. 5. Analysis of the linear correlation of macrobenthos parameters with the dominant fraction in the bottom sample (А, Б) and depth (В, Г). in Species composition and distribution of bivalve mollusks in plankton and benthos in Nevelsky Strait in summer
Рис. 5. АналиЗ линейной коррелЯции параметров макробентоса от доминируюЩей фракции в пробе грунта (А, Б) и глубины (В, Г). Fig. 5. Analysis of the linear correlation of macrobenthos parameters with the dominant fraction in the bottom sample (А, Б) and depth (В, Г).
Рис. 3. Карта-схема пространственного распределениЯ биомассы Macoma balthica. Fig. 3. A schematic map of the spatial distribution of the Macoma balthica biomass. in Species composition and distribution of bivalve mollusks in plankton and benthos in Nevelsky Strait in summer
Рис. 3. Карта-схема пространственного распределениЯ биомассы Macoma balthica. Fig. 3. A schematic map of the spatial distribution of the Macoma balthica biomass.
Рис.1. Карта-схема района исследований. ● – станции отбора планктонных и бентосных проб. Fig.1. A schematic map of the studied area. ● – sampling stations. in Species composition and distribution of bivalve mollusks in plankton and benthos in Nevelsky Strait in summer
Рис.1. Карта-схема района исследований. ● – станции отбора планктонных и бентосных проб. Fig.1. A schematic map of the studied area. ● – sampling stations.
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Allen Brain Atlas
Allen Brain Atlas is an Allen Institute collection of brain map atlases, datasets, APIs, and analysis tools covering mouse, human, and non-human primate brain resources.
Annotated Behaviour and Observability Dataset (ABODe)
ABODe is a University of Edinburgh DataShare dataset for behavior classification in group-housed mice using home-cage video, identities, bounding boxes, ground-plate positions, and annotator labels.
DANDI Archive for NWB datasets
DANDI is a BRAIN Initiative archive for publishing and sharing neurophysiology data, including electrophysiology, optophysiology, and behavioral data packaged as NWB and related standards.
International Brain Laboratory public data
The International Brain Laboratory public data releases expose standardized mouse decision-making experiments, including Neuropixels recordings, widefield calcium imaging, behavior, and session metadata accessed through the ONE API.
OpenNeuro
OpenNeuro is a free, open platform for sharing neuroimaging datasets, with public search, dataset pages, and download paths for web, S3, DataLad, and the OpenNeuro CLI.