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31.
Silicon - Some soda lime borate glasses containing sele- cted Zn2+, Ag+ or Cu2+ ions or all of them were prepared together with their glass ceramic derivatives by thermal heat-treatment two step...  相似文献   
32.
Ho-substituted Li–Ni ferrites with composition L i1.2Ni0.4HoxFe2-xO4; 0≤ x ≤ 0.15 were synthesized by a self-ignited sol-gel process. An annealing temperature of 950 °C is estimated via thermal-gravimetric (TGA) analysis. X-ray diffraction (XRD) scans have confirmed the formation of the ferrite phase with a spinel structure in all samples. Substitution of Ho ions on the B-site significantly reduced the porosity from 38 -to 23% and the crystallite size from 23.4 -to 21.7 nm. Microstructural analysis revealed a denser structure with an increase in Ho content. Dielectric results showed that both the dielectric loss and dielectric constant depict a nonlinear variation with the addition of Ho. Complex impedance behavior with a single semicircle for all samples suggests the predominant effect of the grain boundary mechanism. The substitution of Ho ions in place of Fe ions significantly decreased the electrical conductivity. The anisotropic Ho3+ ions reinforce the L-S coupling which consequently enhanced the coercive force from 145 -to 389 Oe, and thus the anisotropy constant.  相似文献   
33.
The inactivation of lipoxygenase (LOX) in the whole soya bean prevents lipid oxidation that produces an off‐flavour of soya food. The inactivation of lipoxygenase in the whole soya bean by pulsed light (PL) was examined with three distances (5, 7 and 9 cm) from the PL strobe and for different durations. Soya bean was treated with PL with and without ice surrounding the soya bean sample tray for limiting the rise in sample temperature. Results show that without ice surrounding the sample tray, the lowest LOX residual activity was 4.7%, 0.4% and 0.0% for 80‐s duration at 5 cm distance from the PL strobe, 110 s at 7 cm from the strobe and 150 s at 9 cm from the strobe, respectively; the soya bean temperature after treatment was 109.6, 116.3 and 114.8 °C, respectively. The instantaneous temperatures of the soya bean core measured during PL operating were above 100 °C. The lipoxygenase band was disappeared after longest PL treatments of each distance compared with the LOX band control as assessed by electrophoresis. The pulsed light had no negative effect on peroxide value of produced soya milk. However, PL reduced significantly the total solid amount and changed the colour of the produced soya milk. The residual activity with sample cooling by ice during treatment was 79.0%, 98.8% and 95.7%, with sample temperatures of 81.7, 91.2 and 66.9 °C, respectively. This study indicates that PL illumination could fully inactivate LOX in whole soya beans, with the photo‐thermal effect of PL as the main factor responsible for the inactivation of LOX.  相似文献   
34.
Background and aim: Many sophisticated data mining and machine learning algorithms have been used for software defect prediction (SDP) to enhance the quality of software. However, real‐world SDP data sets suffer from class imbalance, which leads to a biased classifier and reduces the performance of existing classification algorithms resulting in an inaccurate classification and prediction. This work aims to improve the class imbalance nature of data sets to increase the accuracy of defect prediction and decrease the processing time . Methodology: The proposed model focuses on balancing the class of data sets to increase the accuracy of prediction and decrease processing time. It consists of a modified undersampling method and a correlation feature selection (CFS) method. Results: The results from ten open source project data sets showed that the proposed model improves the accuracy in terms of F1‐score to 0.52 ~ 0.96, and hence it is proximity reached best F1‐score value in 0.96 near to 1 then it is given a perfect performance in the prediction process. Conclusion: The proposed model focuses on balancing the class of data sets to increase the accuracy of prediction and decrease processing time using the proposed model.  相似文献   
35.
Accurate fall detection for the assistance of older people is crucial to reduce incidents of deaths or injuries due to falls. Meanwhile, vision‐based fall detection system has shown some significant results to detect falls. Still, numerous challenges need to be resolved. The impact of deep learning has changed the landscape of the vision‐based system, such as action recognition. The deep learning technique has not been successfully implemented in vision‐based fall detection system due to the requirement of a large amount of computation power and requirement of a large amount of sample training data. This research aims to propose a vision‐based fall detection system that improves the accuracy of fall detection in some complex environments such as the change of light condition in the room. Also, this research aims to increase the performance of the pre‐processing of video images. The proposed system consists of Enhanced Dynamic Optical Flow technique that encodes the temporal data of optical flow videos by the method of rank pooling, which thereby improves the processing time of fall detection and improves the classification accuracy in dynamic lighting condition. The experimental results showed that the classification accuracy of the fall detection improved by around 3% and the processing time by 40–50 ms. The proposed system concentrates on decreasing the processing time of fall detection and improving the classification accuracy. Meanwhile, it provides a mechanism for summarizing a video into a single image by using dynamic optical flow technique, which helps to increase the performance of image preprocessing steps.  相似文献   
36.
The Journal of Supercomputing - Detection of threat objects concealed in passenger clothing and baggage poses a challenge to aviation security. At present, the detection technology is capable of...  相似文献   
37.
Although many interesting results have been reported by researchers using numeric data mining methods, there are still questions that need answering before textual data mining tools will be considered generally useful due to the effort needed to learn and use them.  相似文献   
38.
In the current work, synthetic polyamide nylon fibers were modified via the strategy of surface molecular imprinting to develop enantio‐selective adsorbent fabrics for chiral recognition of d ‐phenyllactic acid (d‐ PhLA). The nylon fibers were first modified by grafting of polyacrylamide and then the incorporated amide groups were converted into functional amino groups via treatment with NaOCl (Hofmann degradation). The amino‐functionalized nylon fibers (Ny‐NH2) were interacted with the targeted d‐ PhLA enantiomer before crosslinking the amino‐containing grafted chains with glutaraldehyde crosslinker followed by leashing the template d‐ PhLA out of the formed surface polymeric matrix by lowering the pH to 1 to finally produce the desired enantio‐selective adsorbent fibers DP‐Ny. Different instrumental methods such as elemental analysis, Fourier transform infrared spectroscopy, XRD and TGA were employed to examine all the synthetic procedures. SEM was also utilized to observe the morphological appearances of both native and modified nylon fibers. Moreover, the optimum extraction of d‐ PhLA was found to occur at pH 7. Isotherm studies of the prepared DP‐Ny fibers obeyed the common Langmuir linear equation with qm values 130 ± 2 and 75 ± 1 mg g?1 in the case of d‐ PhLA and l‐ PhLA, respectively. Furthermore, the enantiomeric resolution of (±)‐PhLA racemate was successfully carried out by a column technique with enantiomeric excess reaching approximately 78%. © 2019 Society of Chemical Industry  相似文献   
39.
Poly(2-hydroxyethylmethacrylate-co-2-folatethylmethacrylate) was synthesized by free radical polymerization of 2-hydroxyethylmethacrylate with 2-folatethylmethacrylate and folic acid/poly(2-hydroxyethylmethacrylate) solid solutions was prepared by mixing folic acid with poly(2-hydroxyethylmethacrylate) using the solution casting method. The structure and the homogeneity distribution of folic acid in the polymer matrix are characterized by different methods. The diffusion behaviors of water and folic acid through poly(2-hydroxyethylmethacrylate-co-2-folatethylmethacrylate) and poly(2-hydroxyethylmethacrylate) matrixes were found obey to the Fick models. The in vitro cytotoxicity assessed by microculture tetrazolium test assay and the antioxidant activity of poly(2-hydroxyethylmethacrylate-co-2-folatethylmethacrylate) systems determined by 1,1-diphenyl-2-picryl-hydrazyl method revealed no significant toxicity of these systems and has excellent free radical scavenger property which can be as safe candidate in drug-carrier system. The solubility enhancement of folic acid in different pH media is also investigated and the results obtained reveal a maximum of 399–400?mg?L?1. The release dynamic of folic acid from the poly(2-hydroxyethylmethacrylate-co-2-folatethylmethacrylate) containing 5?mol% of folic acid and that from folic acid/poly(2-hydroxyethylmethacrylate) system containing 10?mol% of folic acid have the best intestine/stomach ratio.  相似文献   
40.
In magnetophoresis-based microfluidic systems, the free-flow sorting is achieved by incrementally navigating the magnetic target toward a designated outlet. This is typically enabled using high-gradient magnetic concentrators (HGMCs), axially aligned or slightly slanted with the streaming sample flow. Such axial and incremental magnetic manipulation critically constraints the throughput and the number of targets that can be sorted simultaneously. To overcome these constraints, we present an alternative repulsion-based sorting method. The repulsion force is due that induced, over a limited angular expanse, around a single ferromagnetic wire. The wire is positioned transversally against the focused sample flow. Differentially repelled by the repulsive force, each target deflects from its focused path to follow a ribbon-like trajectory that leads to a spatially addressable outlet. The mediated sorting takes place more rapidly and is confined to the region facing the transversal wire. More importantly, the introduced concept design allows for a throughput that is geometrically scalable with the length of the wire. The functionality of the systems is demonstrated experimentally and numerically to yield the simultaneous and complete multi-target sorting of two and more magnetic beads.  相似文献   
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