Single Nanoparticle Magnetic Spin Memristor

There is an increasing demand for the development of a simple Si‐based universal memory device at the nanoscale that operates at high frequencies. Spin‐electronics (spintronics) can, in principle, increase the efficiency of devices and allow them to operate at high frequencies. A primary challenge for reducing the dimensions of spintronic devices is the requirement for high spin currents. To overcome this problem, a new approach is presented that uses helical chiral molecules exhibiting spin‐selective electron transport, which is called the chiral‐induced spin selectivity (CISS) effect. Using the CISS effect, the active memory device is miniaturized for the first time from the micrometer scale to 30 nm in size, and this device presents memristor‐like nonlinear logic operation at low voltages under ambient conditions and room temperature. A single nanoparticle, along with Au contacts and chiral molecules, is sufficient to function as a memory device. A single ferromagnetic nanoplatelet is used as a fixed hard magnet combined with Au contacts in which the gold contacts act as soft magnets due to the adsorbed chiral molecules.     

Compensation effect in styrene-acrylonitrile copolymer and acrylonitrile-butadiene-styrene terpolymer as explored by thermally stimulated depolarization measurements

Thermally stimulated depolarization currents of styrene-acrylonitrile and acrylonitrile-butadiene-styrene copolymers have been investigated in the high-temperature range. A peak associated with the glass transition temperature was observed which has the characteristic of a dipolar relaxation process. Parameters such as activation energy and relaxation time associated with the dipolar relaxation process have been calculated. The compensation effect is observed to be valid and the value of the compensation temperature differs slightly from one compound to other. The linear relationship between the activation energy and the logarithm of the preexponential factor of the relaxation time is discussed in terms of the compensation temperature and the chain environment.     

Improving the oxygen barrier properties of polyethylene terephthalate by graphite nanoplatelets

Enhancement of the oxygen gas barrier properties of polyethylene terephthalate (PET), used in the packaging industry, is the main objective here. For this purpose, nanocomposites of PET containing graphite nanoplatelets (GNPs) were prepared by melt compounding. The effects of the nanocomposites' structural morphology on oxygen gas permeability were analyzed using a range of thermal, microscopic, and mechanical characterization techniques. The investigated nanocomposite films exhibited GNP exfoliated morphology and good mixing with PET, as well as uniform dispersion within the polymer. All nanocomposite films were shown to possess superior oxygen barrier properties and improved thermal and dimensional stability compared with the plain PET films. In the best case, for 1.5 wt % GNP, the oxygen permeation was reduced by more than 99%. The improved barrier properties are attributed to the direct effect of the GNPs and to their induced increase of degree of crystallinity. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Dielectric‐Screening Reduction‐Induced Large Transport Gap in Suspended Sub‐10 nm Graphene Nanoribbon Functional Devices

The predicted quasiparticle energy gap of more than 1 eV in sub‐6 nm graphene nanoribbons (GNRs) is elusive, as it is strongly suppressed by the substrate dielectric screening. The number of techniques that can produce suspended high‐quality and electrically contacted GNRs is small. The helium ion beam milling technique is capable of achieving sub‐5 nm patterning; however, the functional device fabrication and the electrical characteristics are not yet reported. Here, the electrical transport measurement of suspended ≈6 nm wide mono‐ and bilayer GNR functional devices is reported, which are obtained through sub‐nanometer resolution helium ion beam milling with controlled total helium ion budget. The transport gap opening of 0.16–0.8 eV is observed at room temperature. The measured transport gap of the different edge orientated GNRs is in good agreement with first‐principles simulation results. The enhanced electron–electron interaction and reduced dielectric screening in the suspended quasi‐1D GNRs and anti‐ferromagnetic coupling between opposite edges in the zigzag GNRs substantiate the observed large transport gap.     

Semantic Information Extraction from Multi-Corpora Using Deep Learning

Information extraction plays a vital role in natural language processing, to extract named entities and events from unstructured data. Due to the exponential data growth in the agricultural sector, extracting significant information has become a challenging task. Though existing deep learning-based techniques have been applied in smart agriculture for crop cultivation, crop disease detection, weed removal, and yield production, still it is difficult to find the semantics between extracted information due to unswerving effects of weather, soil, pest, and fertilizer data. This paper consists of two parts. An initial phase, which proposes a data preprocessing technique for removal of ambiguity in input corpora, and the second phase proposes a novel deep learning-based long short-term memory with rectification in Adam optimizer and multilayer perceptron to find agricultural-based named entity recognition, events, and relations between them. The proposed algorithm has been trained and tested on four input corpora i.e., agriculture, weather, soil, and pest & fertilizers. The experimental results have been compared with existing techniques and it was observed that the proposed algorithm outperforms Weighted-SOM, LSTM+RAO, PLR-DBN, KNN, and Naïve Bayes on standard parameters like accuracy, sensitivity, and specificity.     

Effect of Some Additives on Mass Transfer Coefficient at a Vibrating Horizontal Screen

The object of the present work is to study the effect of drag-reducing additives like Polyox WSR 301 and sodium lauryl sulfate (anionic surfactant) on the rate of mass transfer at a vibrating horizontal screen, an electrochemical technique which involved measuring the limiting current of the cathodic reduction of potassium ferricyanide. Variables studied were the concentration of polymer and surfactant, frequency of vibration and amplitude of vibration. It was found that a decrease in the mass transfer coefficient occurs in the presence of surfactant which ranged from 3 to 61.8% depending on the concentration of the surfactant. The addition of a Polyox leads to a decrease in the mass transfer coefficient which ranged from 20 to 74.4% depending on the concentration of the polymer.     

Reactions with 2,3,4,5-Tetrahydro-benzo[b]thiepin-5-one and its Derivatives

2,3,4,5-Tetrahydro-benzo[b]thiepin-5-one, its 7-methyl derivative, and their S, S-dioxides condense with aromatic aldehydes to give the corresponding 4-arylidene derivatives 3 and 4 . Compounds 4 react with hydrazine and phenylhydrazine to yield 3, 3a, 4, 5-tetrahydro-2 H-benzo-[b]thiepino[4, 5-c]pyrazole S, S-dioxide derivatives 5 and 6 . Some of the arylidene derivatives 4 add GRIGNARD reagents to give 7 . The IR spectra of representative examples are discussed.     

Vickers microhardness indentation and fracture mechanics of chalcogenide arsenic-selenium glasses

Measurements of Vickers microhardness have been carried out on As _x Se_1−x glass (0.28 <x < 0.60). The diamond pyramid hardness number as a function of composition revealed a maximum at 40% As, the stoichiometric composition, indicating that this composition is the most ordered and strongest of the alloys. Deviation from stoichiometry was found to increase the disorder and introduce weaker bonds. An attempt was made to use the indentation approach to determine the fracture toughness of the investigated glasses. Therefore, the extent of surface traces of well-developed penny-like (conchoidal) cracks extending from the corners of Vickers indents were measured and found to obey Lawn's relationP/C ^3/2 = constant (whereP is the indenter load andC is the characteristic crack dimension). An approximate value of the fracture toughness was inferred from these measurements.     

Fractionation of Gluten Lipids with Supercritical Carbon Dioxide

Gluten lipids are of two kinds, polar and nonpolar. Both groups consist of a large number of lipids. Gluten lipids can be extracted by conventional solvents as ethanol but also by supercritical carbon dioxide. The high density and the good mass transport properties make the supercritical fluid an excellent solvent. Ethanol extracted gluten lipids have been fractionated with supercritical CO₂ at different pressures and constant temperature. The extract contains triglycerides and free fatty acids, and a more concentrated fraction of polar lipids is left in the extraction vessel. While both polar and nonpolar lipids are soluble in ethanol, only nonpolar lipids are dissolved by supercritical CO₂. An addition of a small amount of ethanol to the CO₂, can, however, increase the solubility of the polar lipids.     

Physical Properties of Butter Oil Fractions Obtained by Supercritical Carbon Dioxide Extraction

Butter oil has been fractionated with supercritical carbon dioxide at 40°C. 125 bar and 350 bar, respectively. The chemical composition and physical properties of the butter oil fractions have been studied with gas chromatography and differential scanning calorimetry (DSC). The polymorphism of the fractions has been studied by X-ray diffraction during crystallization. Fractionation carried out at lower extraction pressure results in higher selectivity. The first fractions collected during the extraction process contain triglycerides which are enriched in short chain fatty acids. The colourless fractions melt and crystallize at a lower temperature compared to the original butter. The residual fraction is enriched in triglycerides with long chain fatty acids, is yellow, melts and crystallizes at a higher temperature. All the investigated fractions shows the β′ form when crystallized from the melt.