The analysis of bioelectrical signals continues to receive wide attention in research as well as commercially because novel signal processing techniques have helped to uncover valuable information ...for improved diagnosis and therapy. This book takes a unique problem-driven approach to biomedical signal processing by considering a wide range of problems in cardiac and neurological applications, the two "heavyweight" areas of biomedical signal processing. The interdisciplinary nature of the topic is reflected in how the text interweaves physiological issues with related methodological considerations. This book is suitable for a final year undergraduate or graduate course as well as for use as an authoritative reference for practicing engineers, physicians, and researchers.
In this paper, for the first time, it is studied the synergetic properties of two different grades of nanocelluloses with different chemical compositions (cellulose nanofibrils-CNF with less than 1% ...of lignin and lignocellulose nanofibrils-LCNF with 16% of lignin). CNF and LCNF were mixed in different ratios to obtain bi-component films. Their performance in terms of transparency, bioactivity, thermo-mechanical and gas barrier properties was evaluated and compared with the performance of the neat CNF films. The presence of LCNF in the formulations conferred antioxidant and UV blocking properties to the films, as well as improved mechanical and barrier properties. Specifically, the incorporation of 25% LCNF to the CNF films increased the mechanical properties (94% increase in tensile stress and a 414% increase in strain at break) and decreased the water vapor transmission rate by 16% and the oxygen transmission rate by 53%. This performance improvement was attributed to the coexistence of nanocelluloses with different chemical composition and morphology. LCNF contributed to increment the interfacial adhesion between cellulose nanofibrils due to the presence of lignin and promote the creation of more tortuous paths for gas molecules. These synergetic properties shown by the CNF/LCNF bi-component films demonstrate high potential to be used as gas barrier packaging solutions.
•CNF and LCNF from residual biomass are used to produce bicomponent nanocellulose films.•LCNF conferred UV-blocking and antioxidant properties to the films.•LCNF presence improved flexibility and tensile strength of CNF films.•All developed bicomponent films display better gas barrier properties than CNF films.•CNF/LCNF formulations have higher potential to be used as barrier coatings/films than CNF.
A Logic for Locally Complete Abstract Interpretations Bruni, Roberto; Giacobazzi, Roberto; Gori, Roberta ...
2021 36th Annual ACM/IEEE Symposium on Logic in Computer Science (LICS),
2021-June-29
Conference Proceeding
Open access
We introduce the notion of local completeness in abstract interpretation and define a logic for proving both the correctness and incorrectness of some program specification. Abstract interpretation ...is extensively used to design sound-by-construction program analyses that over-approximate program behaviours. Completeness of an abstract interpretation A for all possible programs and inputs would be an ideal situation for verifying correctness specifications, because the analysis can be done compositionally and no false alert will arise. Our first result shows that the class of programs whose abstract analysis on A is complete for all inputs has a severely limited expressiveness. A novel notion of local completeness weakens the above requirements by considering only some specific, rather than all, program inputs and thus finds wider applicability. In fact, our main contribution is the design of a proof system, parameterized by an abstraction A, that, for the first time, combines over- and under-approximations of program behaviours. Thanks to local completeness, in a provable triple ⊢ A P c Q, the assertion Q is an under-approximation of the strongest post-condition postc(P ) such that the abstractions in A of Q and postc(P ) coincide. This means that Q is never too coarse, namely, under mild assumptions, the abstract interpretation of c does not yield false alerts for the input P iff Q has no alert. Thus, ⊢ A P c Q not only ensures that all the alerts raised in Q are true ones, but also that if Q does not raise alerts then c is correct.
This authoritative, widely cited book has been used all over the world. The Fourth Edition incorporates the latest developments in the field while maintaining the core objectives of previous ...editions: To correlate properties with chemical structure and to describe methods that permit the estimation and prediction of numerical properties from chemical structure, i.e. nearly all properties of the solid, liquid, and dissolved states of polymers.
Pure nanoparticles of the rare-earth substituted cobalt ferrites CoRExFe2−xO4 (where RE=Nd, Sm and Gd and x=0.1 and 0.2) were prepared by the chemical co-precipitation method. X-ray diffraction, ...Transmission electron microscopy (TEM), d.c. electrical conductivity, Magnetic hysteresis and Thermal analysis are utilized in order to study the effect of variation in the rare-earth substitution and its impact on particle size, magnetic properties like MS, HC and Curie temperature. The phase identification of the materials by X-ray diffraction reveals the single-phase nature of the materials. The lattice parameter increased with rare-earth content for x≤0.2. The Transmission electron micrographs of Nd-, Sm- and Gd-substituted CoFe2O4 exhibit the particle size 36.1 to 67.8nm ranges. The data of temperature variation of the direct current electrical conductivity showed definite breaks, which corresponds to ferrimagnetic to paramagnetic transitions. The thermoelectric power for all compound are positive over the whole range of temperature. The dielectric constant decreases with frequency and rare-earth content for the prepared samples. The magnetic properties of rare-earth substituted cobalt ferrites showed a definite hysteresis loop at room temperature. The reduction of coercive force, saturation magnetization, ratio MR/MS and magnetic moments may be due to dilution of the magnetic interaction.
Transparent electrodes that can maintain their electrical and optical properties stably against large mechanical deformations are essential in numerous applications of flexible and wearable ...electronics. In this paper, we report a comprehensive analysis of the electrical, optical, and mechanical properties of hybrid nanostructures based on graphene and metal nanotrough networks as stretchable and transparent electrodes. Compared to the single material of graphene or the nanotrough, the formation of this hybrid can improve the uniformity of sheet resistance significantly, that is, a very low sheet resistance (1 Ω/sq) with a standard deviation of less than ±0.1 Ω/sq, high transparency (91% in the visible light regime), and superb stretchability (80% in tensile strain). The successful demonstration of skin-attachable, flexible, and transparent arrays of oxide semiconductor transistors fabricated using hybrid electrodes suggests substantial promise for the next generation of electronic devices.
Summary
In this paper, the effects of pressure on starch properties were summarised and discussed. Firstly, high pressure can decrease the relative crystallinity of starch. After a 600 MPa treatment ...for 10–30 min, the relative crystallinity is reduced by about 37.1% on average. Meanwhile, high pressure can transform the A‐type or C‐type crystal into B‐type crystal. The destruction of high‐pressure treatment to starch crystalline structure is mainly achieved by disturbing the regular arrangement of double‐helixes, instead of directly destroying the double‐helix structure. Secondly, high pressure showed different effect trends on pasting and thermal properties of different starches. In most cases, the enthalpy of starch would become 0 after a 600 MPa treatment for 10–30 min. Thirdly, high pressure can increase retrogradation rate by 1.12–1.81 times. Fourthly, high‐pressure treatment increases the G′, G′′, apparent viscosity and yield stress of starch gel, and has different effect trends on flow behaviour index and consistency coefficient of different starches. Fifthly, high pressure can increase the RS content, up to 466.7%. This paper can provide reference for the application of high‐pressure technology in starch processing and modification.
High‐pressure decreases the relative crystallinity of starch and transforms the A or C‐type into B‐type crystal. In addition, high‐pressure increases the retrogradation rate and RS content of starch. Moreover, high‐pressure shows different effect trends on pasting and thermal properties of different starches.
Wettability of Graphene Raj, Rishi; Maroo, Shalabh C; Wang, Evelyn N
Nano letters,
04/2013, Volume:
13, Issue:
4
Journal Article
Peer reviewed
Graphene, an atomically thin two-dimensional material, has received significant attention due to its extraordinary electronic, optical, and mechanical properties. Studies focused on understanding the ...wettability of graphene for thermo-fluidic and surface-coating applications, however, have been sparse. Meanwhile, wettability results reported in literature via static contact angle measurement experiments have been contradictory and highlight the lack of clear understanding of the underlying physics that dictates wetting behavior. In this work, dynamic contact angle measurements and detailed graphene surface characterizations were performed to demonstrate that the defects present in CVD grown and transferred graphene coatings result in unusually high contact angle hysteresis (16–37°) on these otherwise smooth surfaces. Hence, understanding the effect of the underlying substrate based on static contact angle measurements as reported in literature is insufficient. The advancing contact angle measurements on mono-, bi-, and trilayer graphene sheets on copper, thermally grown silica (SiO2), and glass substrates were observed to be independent of the number of layers of graphene and in good agreement with corresponding molecular dynamics simulations and theoretical calculations. Irrespective of the number of graphene layers, the advancing contact angle values were also in good agreement with the advancing contact angle on highly ordered pyrolytic graphite (HOPG), reaffirming the negligible effect of the underlying substrate. These results suggest that the advancing contact angle is a true representation of a graphene-coated surface while the receding contact angle is significantly influenced by intrinsic defects introduced during the growth and transfer processes. These observations, where the underlying substrates do not affect the wettability of graphene coatings, is shown to be due to the large interlayer spacing resulting from the loose interlamellar coupling between the graphene sheet and the underlying substrate. The fundamental insights on graphene–water interactions reported in this study is an important step towards developing graphene-assisted surface coatings for heat transfer and microfluidics devices.
Summary
Within first principles calculations, the electronic structure, thermodynamic, mechanical stability, magnetism, and phonon properties of the inverse perovskite (Na3OCl) have been summed up. ...The Birch‐Murnaghan derived lattice constant and bond‐lengths are identical, when compared to the experimental data. A direct energy gap of 2.18 eV observed from the band structure reveals the semiconducting nature of the present oxide. Also, the application of strain on electronic properties predicts the decrease in bandgap with respect to compressive strain and vice versa. The constituent nonmagnetic atoms in its crystal propose the total magnetic moment to be zero and the same is supported by susceptibility data. In addition to the negative Cauchy's pressure, the small bulk modulus compared to Young's modulus determined from elastic constants, possibly claims it as a brittle material. Also, the temperature dependent Gruneisen parameter (1.58) and Debye temperature (382.27 K) are determined to reveal the lattice thermal conductivity (κ = 6.48 W/mK) at room temperature.
Controlling the bandstructure through local-strain engineering is an exciting avenue for tailoring optoelectronic properties of materials at the nanoscale. Atomically thin materials are particularly ...well-suited for this purpose because they can withstand extreme nonhomogeneous deformations before rupture. Here, we study the effect of large localized strain in the electronic bandstructure of atomically thin MoS2. Using photoluminescence imaging, we observe a strain-induced reduction of the direct bandgap and funneling of photogenerated excitons toward regions of higher strain. To understand these results, we develop a nonuniform tight-binding model to calculate the electronic properties of MoS2 nanolayers with complex and realistic local strain geometries, finding good agreement with our experimental results.
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