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Aramid pulp (AP) is a highly fibrillated form of fiber， with excellent heat resistance, wear resistance, size stability, and other beneficial properties, that can be dispersed in rubber or resin matrix systems. Its fibrillation results in a large surface area. However, AP easily tangles and aggregates between fibers because of its large surface area. Consequently, it experiences difficulty in dispersing in matrices, especially when a relatively large amount of pulp is needed to be mixed. In this study, a SiO2 nanoparticle was synthesized on the surface of AP through the hydrolysis of tetraethyl orthosilicate to improve the dispersion of AP in an epoxy matrix. Fourier transform infrared spectroscopy, X‐ray diffraction, thermogravimetric analysis, X‐ray photoelectron spectroscopy, and scanning electron microscopy showed that SiO2 nanoparticles coated on the pulp could improve the thermal and mechanical properties. The optimum treatment concentration was 0.15 mol/L. Dynamic mechanical analysis tests indicated when AP modified by SiO2, the E' is higher due to the uniformly diffusion and enhanced interfacial adhesion for load transfer from the epoxy to AP. But Tg is lower as the flexibility chain SiOSi in epoxy. In comparison with the properties of the unmodified AP, the tensile strength and modulus of modified pulp/epoxy composites increased by 53.5% and 160.4%, respectively. Therefore, the dispersion and interface combination of AP modified by SiO2 in the epoxy improved because of the interaction of AP with SiO2 through the hydrogen bonding and crosslinking of SiO2 with epoxy. [ABSTRACT FROM AUTHOR]

Nitrile butadiene rubber (NBR) is widely used in the production of oil and fuel‐resistant rubber parts. Poly(p‐phenyleneterephalamide) (PPTA) pulp is used as a reinforcing fabric in NBR composites to improve its mechanical properties despite the weak bonding between NBR and PPTA pulp. In this work, PPTA pulp was modified by interfacial polymerization of dopamine (DOPA). A surface‐adherent poly(dopamine) (PDA) film was formed on the surface of the PPTA pulp, which improved bonding to NBR and mechanical properties of the prepared composites. The surface of the modified PPTA pulp was characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, and X‐ray photoelectron spectroscopy. The results demonstrate that PDA was successfully functionalized on the PPTA pulp and that the surface of the composite was rougher after modification. The effects of treatment conditions on the mechanical properties of NBR/pulp composites were also investigated. The tensile strength markedly improved with treating time of 30 h at a DOPA concentration of 2 g/L. Strong interactions, including hydrogen bonding and adsorption, play an important role in the tensile strength of the material. Our results demonstrate that surface modification by PDA is beneficial for improving the strength of the NBR matrix. POLYM. COMPOS., 40:E476–E483, 2019. © 2018 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

To optimize the accuracy of near-infrared non-invasive hemoglobin (Hb) clinical detection, high-performance instrument and prepossessing algorithm have been investigated. A near-infrared spectrophotometric system was constructed adopting InGaAs detector array with 16 pixels and plane grating spectrometer to obtain high signal noise ratio (SNR) spectral data. In our experiment, we applied the device independently to collect spectra data from 91 volunteers’ fingertips non-invasively. Two prediction tests were conducted to verify the effects of preprocessing algorithms improving the accuracy of near-infrared Hb detection and exclude the occasionality of satisfactory results in a single trial. Our non-invasive Hb detection methods were based on partial least squares (PLS). In each test, PLS, MSC coupled with PLS, DOSC coupled with PLS, three methods for non-invasive Hb detection, were analyzed respectively. The results of two trials showed that only DOSC & PLS performed excellently in both predictive ability and stability, obviously better than other two methods. Relative RMSEP was 6.16% in predicting test 1, 6.08% in predicting test 2, almost reaching the requirements of clinical application. It indicates that our independent-developed high-performance instrument and the method DOSC coupled with PLS are promising in non-invasive Hb detection clinical application. [ABSTRACT FROM AUTHOR]

Poor dispersion is a major disadvantage of aramid pulp (AP) reinforced composites. In this study, nano‐silica (SiO2), as the surface modifier and reinforcing agent, was synthesized on AP surfaces to improve the dispersed character in ethylene‐propylene‐diene elastomer (EPDM) using supercritical carbon dioxide (scCO2). The influence of the temperature of scCO2 on treated AP, configuration of the surface, and mechanical performance of AP/EPDM composites were studied. Based on the results of Fourier transform infrared spectroscopy and X‐ray photoelectron spectroscopy, SiO2 was chemically grafted onto the AP surface. The SiO2 nanoparticles were uniformly deposited on the AP surface, and the roughness of AP was increased based on the SEM results. The optimum temperature of the supercritical reaction was 100°C considering the results of all the tests. Under the optimum temperature and with 10 phr of AP, the mechanical properties, oil resistance, and dynamic mechanical properties of the SiO2‐AP/EPDM composites were investigated. The tensile strength and tear strength of the SiO2‐AP/EPDM were improved by 121.1 and 134.9%, respectively, compared with that of the pure AP/EPDM composites. The fracture surface of the SiO2‐AP/EPDM composites showed that SiO2‐modified AP had a good dispersion in EPDM, and AP and EPDM had good interfacial bonding. Dynamic mechanical analysis results showed that the storage modulus of the composites was improved greatly compared with the pure AP/EPDM, and the loss factor also increased. The oil resistance of the composites was also improved. [ABSTRACT FROM AUTHOR]

Subtracted blood volume spectrometry (SBVS) can eliminate the background information in near infrared spectroscopy (NIRS) noninvasive biochemical sensing. However, the spectrum obtained by this method is accompanied by serious noises which are to the disadvantage of the calibration models. Empirical mode decomposition (EMD) was applied to restrict the noises in order to improve the performance of subtracted blood volume spectrometry. Certain criteria were used to evaluate the performance of the method, such as the average correlation coefficient, and the average and standard deviation of the Euclidean distance. EMD was applied to three subtracted spectra with different ΔL, and the criteria were calculated accordingly. All of the criteria were improvement. Especially for the subtracted spectra with ΔL=0.5mm, the correlation coefficient increased from 0.9970 to 0.9999, the average Euclidean distance decreased from 0.0265 to 0.0118, and the standard deviation of the Euclidean distance decreased from 0.0148 to 0.0033 after EMD filtering. The PLS models of the processed spectra were promoted as well. These preliminary results suggest that EMD is a promising means of improving the performance of subtracted blood volume spectrometry. [ABSTRACT FROM AUTHOR]

Subtracted blood volume spectrometry (SBVS) can eliminate the background information in near infrared spectroscopy (NIRS) noninvasive biochemical sensing. However, the spectrum obtained by this method is accompanied by serious noises which are to the disadvantage of the calibration models. Empirical mode decomposition (EMD) was applied to restrict the noises in order to improve the performance of subtracted blood volume spectrometry. Certain criteria were used to evaluate the performance of the method, such as the average correlation coefficient, and the average and standard deviation of the Euclidean distance. EMD was applied to three subtracted spectra with different ΔL, and the criteria were calculated accordingly. All of the criteria were improvement. Especially for the subtracted spectra with ΔL=0.5mm, the correlation coefficient increased from 0.9970 to 0.9999, the average Euclidean distance decreased from 0.0265 to 0.0118, and the standard deviation of the Euclidean distance decreased from 0.0148 to 0.0033 after EMD filtering. The PLS models of the processed spectra were promoted as well. These preliminary results suggest that EMD is a promising means of improving the performance of subtracted blood volume spectrometry. [ABSTRACT FROM AUTHOR]

Aramid fibers with low density and high strength, modulus, and thermal resistance are widely used in applications such as bulletproof vests and cables. However, owing to their chemical structure, they are sensitive to ultraviolet light, which degrades the fibers' useful mechanical properties. In this study, titanium dioxide (TiO2) nanoparticles were synthesized both on the aramid III fiber surface and in the interfacial space between the fibrils/microfibrils in supercritical carbon dioxide (scCO2) to improve the UV resistance of aramid fibers. The effects of scCO2 treatment pressure on the TiO2 structure, morphology, surface composition, thermal stability, photostability, and mechanical properties were investigated using Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, thermogravimetric analysis, ultraviolet–visible spectroscopy, and single-fiber test. The results show that amorphous TiO2 formed on the fiber surface and the interface between fibrils/microfibrils, and decreased the photodegradation rate of the aramid III fiber. Moreover, this modification can also improve the tensile strength via treatment at low temperature and without the use of a solvent. The simple synthesis process in scCO2, which is scalable, is used for mild modifications with a green solvent, providing a promising technique for synthesizing metal dioxide on polymers. [ABSTRACT FROM AUTHOR]

Using TiO 2 on slides to facilitate photo-catalysis of silver nano-particles (AgNPs) is a simple and versatile way of making silver based solid SERS substrates. However, due to the difficulty of getting optimal surface AgNPs structure, it is difficult to reach optimal enhancement factor or measurement uniformity with this method. In this research, production conditions and setups, ranging from dip-coating to photo-catalysis are investigated. Spectral analysis show that some conditions, such as time of calcination and the purity of UV light used in photo-catalysis, affect the resulting SERS substrates more significantly. The overall performance of substrates made using this method is increased; sensitivity is increased so that the limit of detection for Rhodamin 6G (R6G) is as low as 10 −8 M, and the signature peak of R6G at 1650 cm −1 measured from different spots on substrates has a standard deviation of less than 20%. [ABSTRACT FROM AUTHOR]

Raman spectroscopy is a novel method of food analysis and inspection. It is highly accurate, quick, and noninvasive. The investigation and monitoring of food processing is important because most of the foods humans eat today are processed in various ways. In this article, the use of Raman spectroscopy in food processes, such as fermentation, cooking, processed food manufacturing, and so on, are explored. The characteristics and difficulties of the Raman inspection of these processes are also discussed. According to the various research reports, Raman spectroscopy is a very powerful tool for monitoring these food processes in lab environments and is likely to see usage in situ in the future. [ABSTRACT FROM PUBLISHER]

This study attempted to investigate the transfer rule of the axial stress and springback models at the different locations of the compression chamber in the compression process of alfalfas, in which the alfalfa was compressed from the loose state into a grass piece. By taking dried high-quality alfalfa as the experimental material and 4 kg as the feeding capacity, with 5 different cross-section sizes (namely 360 mm×460 mm, 385 mm×460 mm, 410 mm×460 mm, 460 mm×460 mm and 510 mm×460 mm) of the compression chamber, the compression experiments were conducted under the conditions of a given compression chamber length, and initial density and moisture content of alfalfa. In order to measure the axial stress, including the compression and springback stress, the 10 moveable pressure sensors were used for the cross-section size of the compression chamber, and 2 pressure sensors and 3 displacement sensors were installed in each section. The compression and springback stress, the location of the grass piece in the compression chamber, the amount of compression, and springback value were obtained and stored in an Excel spreadsheet table by the data acquisition system based on virtual instrument technology, and the online curves of the axial force, the compression displacement, and the thickness of the grass pieces were displayed. All data was imported into the software Matlab and the axial stress curves versus the location of the grass piece in the compression of alfalfa were given. Then curve fitting of the maximum stress and the minimum springback stress were done respectively, the transfer rule of the compression and springback stress and the corresponding mathematic model were obtained. The results showed that the squared multiple correlation coefficient was greater than 0.9091, indicating that the compression and springback stress were closely related to the location of the grass piece and that the model regression effect was better. The compression and springback stresses had the similar transfer rules for different cross-section sizes of the compression chamber, and the cross-section size of the compression chamber had effects on the maximum compression stress and maximum springback stress of alfalfa. The compression stress required from loose alfalfa into the grass piece was highest, which was a fundamental parameter in designing the baler. The compression stress of 4-5 the grass piece was higher in the front of the compression chamber but lower in the rear parts of the compression chamber. It suggested that: 1) the suitable length for the compression chamber was 900-1 000 mm; and 2) the reinforcement structures should be added in the front part of the compression chamber to satisfy the strength and stiffness and to decrease baler weight. The study revealed that the envelop line of minimum spingback stress increased with increasing compression displacement, and the trend was opposite when it reached a certain location. Eventually, the difference between the axial compression and springback force of the grass piece was decreased and then became stable. It indicated that the damping plate should be set at the front part and the rear of the compression chamber, which would lead to the maximum springback force occurring in the compression process. As such, the baling efficiency and qualified products were improved. The results here provide valuable information for parameters optimization in the compression process and power choice. [ABSTRACT FROM AUTHOR]

The flower is the main organ that produces essential oils in many plants. The yield of raw flowers and the number of secretory epidermal cells are the main factors for essential oil production. The cultivated rose species "Pingyin 1" in China was used to study the effect of RrANT1 on floral organ development. Eighteen AP2 transcription factors with dual AP2 domains were identified from Rosa rugosa genome. RrANT1 belonged to euANT. The subcellular localization results showed that RrANT1 protein is localized in the nucleus. The relative expression level of RrANT1 in the receptacle is higher than that in petals in the developmental stages, and both decreased from the initial phase to senescence. Compared with the RrANT1 expression level in petals in the blooming stage, RrANT1 expression level was significant in petals (~48.8) and highest in the receptacle (~102.5) in the large bud stage. It was only highly expressed in the receptacle (~39.4) in the blooming period. RrANT1 overexpression significantly increased petunia flower and leaf sizes (~1.2), as well as flower fresh weight (~30%). The total number of epidermis cells in the petals of overexpressing plants significantly increased (>40%). This study concluded that RrANT1 overexpression can increase the size and weight of flowers by promoting cell proliferation, providing a basis for creating new rose germplasm to increase rose and essential oil yield. [ABSTRACT FROM AUTHOR]

The carbon nanotube (CNT) auxiliary layers are suggested to reduce the high driving voltage in ac plasma display panel (AC-PDP). The CNT layer, which was integrated on dielectric layer overlapping the PDP bus electrode, was formed by electrophoretic deposition without sheltering further plasma emission light. The effective CNT pretreatment, uniform and thickness distribution of CNTs in the layer result in the excellent field-emission properties of low turn-on field (1.7 \V/\mu\m), which was proved to effectively reduce the discharge voltage of display cell with A-type (CNT layer is at the middle of indium–tin-oxide electrode) in a series of discharge testing. The lowest sustain voltage for turning on the cells was reduced by 30–40 V. The FE-PDP theoretical model was proposed for explaining the testing results. [ABSTRACT FROM AUTHOR]