DBN wavelet transform denoising method in soybean straw composition based on near-infrared rapid detection

In Hei Longjiang Province of China, ten million tons of soybean straws are produced every year, most of which are burned or discarded. The comprehensive utilization rate is less than 5 %. However, as a kind of high-quality raw material resources, the soybean straw is the main material when producing fuel ethanol and biodiesel. The traditional chemical detection technology was always applied to test the quality of straws’ internal components, which needs long time and high cost. Therefore, this research adopted near-infrared spectroscopy technology to establish models to achieve rapid detection of straw’s internal components. One hundred and fifty-two samples of straw were collected within Heilongjiang Province, and the main ingredients, lignin and hemicellulose, were chosen as the research objects. K-stone method is used to divide into calibration and validation sets. The correlation coefficient is adopted to select and validate characteristic bands. After removal of the abnormal sample by concentration of residual method, the emphasis is put on the effect of removal of spectrum noise by applying the wavelet transform. The experimental results are that the model has good stability under the full spectrum band 4000–12,000 cm^?1. After the removal of 3 lignin and 3 hemicellulose samples, respectively, the R ² of calibration set of lignin and hemicellulose models increased significantly, from 0.5836436 and 0.4994598 to 0.6994097 and 0.6943559, respectively. However, after the 5-layer decomposition of DB2 wavelet, the R ² increased to 0.8075574 and 0.8214309 separately. The validation set’s root mean square error prediction (RMSEP) fell from 0.7738772 and 0.3069899 to 0.5979685 and 0.2761462. After the conversion, the relative standard deviations (RSD) are 1.92 and 1.86 %, respectively. Unknown samples can be real-time predicted in short times after building the model, and the prediction process needs only 1960s. The experiments show that it is feasible to employ near-infrared spectroscopy method for rapid detection of straw components, which provides a new method to detect the straw ingredients rapidly in the future.     

Effect of Sub-T_g Annealing on the Corrosion Resistance of the Cu–Zr Amorphous Alloys

Despite the economy of material cost and excellent toughness of Cu-based amorphous alloys, especially Cu_(50)Zr_(50), their poor corrosion resistance to a chloride medium limits their widespread applications. In this study, corrosion tests were performed on the Cu_(50)Zr_(50) amorphous alloy with different degrees of short-range order, which were prepared by annealing below the glass transition temperature(T_g). It was found that the corrosion resistance of amorphous alloys is improved to a significant level when the alloys were heated below T_g. Calorimetric studies showed that thermally activated relaxation process of created disorder, which occurs during sub-T_gannealing, is responsible for the improvement in the corrosion resistance. Molecular dynamics simulations performed on the Cu–Zr amorphous alloys demonstrated that the relaxation process of the alloys is associated with the formation of energetically stable icosahedra and icosahedron-like structures. Our study highlights the effects of sub-T_gannealing on the improvement in the corrosion resistance of the amorphous alloys from the viewpoint the relaxation process of the short-range orders.     

Dispersion of Single-Walled Carbon Nanotubes in Water with Polyphosphazene Polyelectrolyte

A polyphosphazene polyelectrolyte was prepared as a dispersing agent of SWNTs in water. Poly(organophosphazene) was prepared by sequential treatment of poly(dichlorophosphazene) with sodium 4-phenylphenoxide, sodium phenoxide, and sodium trifluoroethoxide in THF. Their substitution percentages were 60, 24, and 16%, respectively. A water-soluble polyphosphazene polyelectrolyte was obtained by sulfonation of aromatic rings by using fuming sulfuric acid. SWNTs were dispersed in an aqueous polymer solution by sonication to give a black homogeneous dispersion. The supramolecular association between the nanotube and the sulfonated polyphosphazene was investigated by TEM, SEM, and AFM. The SEM image of the cleaved edge of the bucky paper, obtained by filtration of the dispersion of SWNTs, showed the nanotubes uniformly wrapped with the polymer. Their diameters were about 30 nm, suggesting small bundles of SWNTs rather than individual SWNTs. Individual SWNTs coated with the polymer were also observed by TEM. The total diameter of the coated tube was about 10 nm and a polymer layer thickness was lager than 4 nm. This paper is dedicated to Professor Harry R. Allcock in recognition of his outstanding contributions to polymer chemistry and his inspirational teaching.     

CARBOHYDRATE UTILIZATION and GROWTH KINETICS IN the PRODUCTION of YOGURT FROM SOYMILK PART I: EXPERIMENTAL METHODS

ABSTRACT. Growth and sugar utilization of Lactobacillus bulgaricus and Streptococcus thermophilus were measured in soymilk. Total cell counts in the inoculum were made using the Breed smear. Correlations were developed between direct microscopic count and biomass dry weight for Lactobacillus bulgaricus and for Streptococcus thermophilus. A 1 g to 1 g ratio of the pure cultures was found to be superior to a 1:1 cell number ratio for the mixed culture inoculum. Carbohydrate substrate concentrations (sucrose and stachyose) were followed by high performance liquid chromatography. the methodologies for making these measurements on set cup style soymilk yogurts were developed and checked for precision in this study.     

Pseudomorphic AlGaAs/InGaAs/GaAs High Electron Mobility Transistors with Super Low Noise Performances of 0.41 dB at 18 GHz

Fully passivated low noise AlGaAs/InGaAs/GaAs pseudomorphic (PM) HEMT with wide head T-shaped gates were fabricated by dose split electron beam lithography (DSL). The dimensions of gate head and footprint were optimized by controlling the splitted pattern size, dose, and spaces of each pattern. We obtained stable T-shaped gate of 0.15 μm gate length with 1.35 μm-wide head. The maximum extrinsic transconductance was 560 mS/mm. The minimum noise figure measured at 18 GHz at V_ds = 2 V and I_ds = 17 mA was 0.41 dB with associated gain of 8.19 dB. At 12 GHz, the minimum noise figure and an associated gain were 0.26 and 10.25 dB, respectively. These noise figures are the lowest values ever reported for GaAs-based HEMTs. These results are attributed to the extremely low gate resistance of wide head T-shaped gate having a ratio of the head to footprint dimensions larger than 9.     

A 3.5 in 230 Mbytes read-channel chip set for magneto-optical diskdrives

A read-channel chip set for rewritable 3.5 in 230 Mbytes magneto-optical disk drives (MOD) is presented. The front-end chip includes an automatic gain control (AGC) circuit, a programmable six-pole two-zero equiripple filter/equalizer, a DC restore circuit, and pulse detectors. The back-end contains a frequency synthesizer phase-locked loop (PLL) and a data separator PLL with 3:1 operating range to support a constant density recording with 8-24 Mb/s data rate (or code rate of 16 to 48 Mb/s) in (2, 7) run-length limited (RLL) encoding format. The architecture of the chip provides high degree of programmability through a serial microprocessor interface, fast switching (<1 μs) between sector mark and data detector modes, and four levels of power management in a 1.5 μm 4 GHz BiCMOS process. With a nominal power supply of 5 V, the chip set dissipates 600 mW during normal operation and 1 mW during sleep mode     

Mn valence state and electrode performance of perovskite-type cathode La0·8Sr0·2Mn1 − x Cu x O3 − δ (x = 0, 0·2) for intermediate-temperature solid oxide fuel cells

Cu-free and Cu-doped LSM system, La_0·8Sr_0·2Mn_1???x Cu _x O_3???δ (x?=?0, 0·2), with perovskite structure were prepared using an EDTA combined citrate process and the effects of Cu ion at B-site were investigated. Electrical conductivity and polarization resistance of the Cu-doped LSM were 210 S·cm^???1 at 750 °C, and 2·54 Ω · cm² at 800 °C, respectively which were better than those of the Cu-free LSM. This indicated that the electrode performance of LSM was improved by the addition of Cu. The oxidation state of Mn ions increased with addition of Cu. The increase in the oxidation state of Mn ions was due to the formation of Mn^4?+? ions and oxygen vacancies. The addition of Cu ions to LSM systems could lead to enhanced electrode performance for oxygen reduction reactions originating from the change in valence of Mn ions.     

Resilient Security Mechanism for Wireless Ad hoc Network

A wireless multihop network is emerging as one of the most important technologies in the field of ubiquitous networking. However, a number of formidable challenges remain, several of the most crucial been associated with robustness and network security. In this paper, we introduce a comprehensive resilient security framework for wireless ad hoc networks that are using multipath routing. It deploys an integrated multisignatures scheme and uses a self-certified public keying technique to ensure secure route discovery. In addition, it uses the Schnorr signature scheme along with an information dispersal algorithm to ensure secure data transfer. We provide security analysis of the proposed approach and compare it with several existing popular schemes. It can be seen that the proposed approach is more secure than other existing schemes. We also evaluated the proposed approach by means of computer simulation and compared its performance to that of the existing popular schemes. The results are in favor of the proposed technique in terms of efficiency and effectiveness.