Removal of difenoconazole and nitenpyram by composite calcium alginate beads during apple juice clarification.

A novel genipin crosslinked calcium alginate/chitosan/polydopamine composite beads (g-Alg/CS/PDA) was synthesized for the removal of residual difenoconazole and nitenpyram during the clarification of apple juice. The composite beads with low potential health risks for all of the main materials were natural, green and biocompatible. Since g-Alg/CS/PDA can both clarify and adsorb, pesticide residues could be removed during the clarification of juice without additional steps. The g-Alg/CS/PDA beads were characterized, and the adsorption parameters, including the pesticide residue levels, adsorption time, pH, ionic strength, fructose concentration and adsorbent dose, were optimized. The adsorption data were fitted to the Freundlich isotherm model (R2 = 0.9604, 0.9625) and the pseudo-second-order kinetic model (R2 = 0.9993, 0.9999). The results indicated that the adsorption behavior of beads was heterogeneous. Moreover, the rate was controlled by several factors. The adsorption mechanism of two pesticides was also discussed. Hydrophobic and π-π conjugation interactions played a dominant role for the adsorption of difenoconazole, while hydrogen bonding and electrostatic interactions were the main factors for nitenpyram.

Dynamic Properties and Fractal Characteristics of 3D Printed Cement Mortar in SHPB Test.

Comparing with the traditional construction process, 3D printing technology used in construction offers many advantages due to the elimination of formwork. Currently, 3D printing technology used in the construction field is widely studied, however, limited studies are available on the dynamic properties of 3D printed materials. In this study, the effects of sand to binder ratios and printing directions on the fractal characteristics, dynamic compressive strength, and energy dissipation density of 3D printed cement mortar (3DPCM) are explored. The experiment results indicate that the printing direction has a more significant influence on the fractal dimension compared with the sand to binder ratio (S/B). The increasing S/B first causes an increase and then results in a decline in the dynamic compressive strength and energy dissipation of different printing directions. The anisotropic coefficient of 3DPCM first is decreased by 20.67%, then is increased by 10.56% as the S/B increases from 0.8 to 1.4, showing that the anisotropy is first mitigated, then increased. For the same case of S/B, the dynamic compressive strength and energy dissipation are strongly dependent on the printing direction, which are the largest printing in the Y-direction and the smallest printing in the X-direction. Moreover, the fractal dimension has certain relationships with the dynamic compressive strength and energy dissipation density. When the fractal dimension changes from 2.0 to 2.4, it shows a quadratic relationship with the dynamic compressive strength and a logarithmic relationship with the energy dissipation density in different printing directions. Finally, the printing mortar with an S/B = 1.1 is proved to have the best dynamic properties, and is selected for the 3D printing of the designed field barrack model.

Improvement and Soil Consistency of Sand-Clay Mixtures Treated with Enzymatic-Induced Carbonate Precipitation.

Recently, microbially induced carbonate precipitation (MICP) has been studied as an alternative for the improvement of sand-clay mixtures. However, the cementing uniformity of MICP-treated sand-clay mixtures cannot be guaranteed. In this present study, enzymatic-induced carbonate precipitation (EICP) was used to deal with it. The ions used in kaolin clay was predicted to affect the production rate for calcium carbonate (CaCO3), which was studied using the calcification test. The solidification test was conducted using two different methods (the premixing method and the diffusion method). The permeability, unconfined compressive strength and the content of CaCO3 of treated samples were obtained to evaluate the solidification effect of the EICP method. Moreover, in EICP treatment, the particle aggregation decreased the liquid limit, but the addition of solution increased it. Therefore, there were contrary effects to the soil consistency. In this study, the two types of liquid limits of treated samples were measured with deionized water and 2M-NaCl brine, respectively. The results show that the Al2O3, NaCl and MgCl2 in the kaolin clay had a slight impact on the production rate for CaCO3, while FeCl3 significantly inhibited it. The EICP method can improve sand-clay mixtures and decrease their permeability. Different from MICP, the EICP method can guarantee the uniformity of treated samples. Moreover, the liquid limit of the sample treated with the premixing method decreased, while that of the sample treated with the diffusion method increased firstly and then decreased with the increasing treatment cycles. Different from the deionized water, the pore-fluid chemistry had a larger effect on the liquid limit with 2M-NaCl brine.

The effects and mechanism of using ultrasonic dishwasher to remove five pesticides from rape and grape.

In this study, the ultrasonic dishwasher was used to remove five pesticides known to be frequently used on rape and grape. As compared with normal water washing, washing with the ultrasonic dishwasher was demonstrated to be more effective for pesticides removal, achieving removal rates between 14.7% and 59.8% on rape, and between 72.1% and 100% on grape. However, there were significant differences in order of the removal rate of five pesticides on rape and grape. From the adsorption experiments and analysis via Freundlich equation, the adsorption index (n, 0.551-1.056 on rape and 0.362-1.478 on grape) and adsorption coefficient (KF, 10-2.47-10-1.65 and 10-3.64-10-1.56 (mg·dm-2)/(mg·L-1)-n on rape and grape) were obtained. Taken together with the observation of the matrix surface by scanning electron microscopy and the evaluation of the physicochemical properties of pesticides, the different pesticides removal may be related to surface structure of the matrix.

Removal of nine pesticide residues from water and soil by biosorption coupled with degradation on biosorbent immobilized laccase.

Biosorbents prepared with peanut shell and wheat straw were act as supports for the immobilization of Aspergillus laccase, and the redox mediator syringaldehyde (SA) was used to improve laccase-catalyzed degradation of nine pesticide residues, including isoproturon, atrazine, prometryn, mefenacet, penoxsulam, nitenpyram, prochloraz, pyrazosulfuron-ethyl and bensulfuron-methyl. Pesticides in water and soil samples were effectively removed via biosorbent concentration and subsequent immobilized laccase degradation on peanut shell or wheat straw supports. The Langmuir equation and Freundlich equation described the biosorption isotherms of the nine pesticides. Parameters that affect the degradation was also investigated. With concentration of pesticides and SA of 6.0 mg L-1 and 1 mmol L-1, over 54.5% and 65.9% of pesticides were removed in water in 3 days with a biosorbent immobilized laccase dose of 25 g L-1 for peanut shell immobilized laccase and wheat straw immobilized laccase, respectively. In the treatment of pesticide in soil with a biosorbent dose of 50 g (kg soil)-1, with the maximum degradation rates ranged from 20.9 to 92.9% and 14.7-92.0% in 7 days for peanut shell immobilized laccase and wheat straw immobilized laccase, respectively. Therefore, laccase immobilized on biomass materials has a strong potential for the effective removal of pesticide pollutants from water and soil by biosorption coupled with degradation.

From Signal to Image: Enabling Fine-Grained Gesture Recognition with Commercial Wi-Fi Devices.

Gesture recognition acts as a key enabler for user-friendly human-computer interfaces (HCI). To bridge the human-computer barrier, numerous efforts have been devoted to designing accurate fine-grained gesture recognition systems. Recent advances in wireless sensing hold promise for a ubiquitous, non-invasive and low-cost system with existing Wi-Fi infrastructures. In this paper, we propose DeepNum, which enables fine-grained finger gesture recognition with only a pair of commercial Wi-Fi devices. The key insight of DeepNum is to incorporate the quintessence of deep learning-based image processing so as to better depict the influence induced by subtle finger movements. In particular, we make multiple efforts to transfer sensitive Channel State Information (CSI) into depth radio images, including antenna selection, gesture segmentation and image construction, followed by noisy image purification using high-dimensional relations. To fulfill the restrictive size requirements of deep learning model, we propose a novel region-selection method to constrain the image size and select qualified regions with dominant color and texture features. Finally, a 7-layer Convolutional Neural Network (CNN) and SoftMax function are adopted to achieve automatic feature extraction and accurate gesture classification. Experimental results demonstrate the excellent performance of DeepNum, which recognizes 10 finger gestures with overall accuracy of 98% in three typical indoor scenarios.

Protective effects of CVPM on vascular endothelium in rats fed cholesterol diet.

BACKGROUND: The cardiovascular protective mixture (CVPM) is a concoction of nine Chinese traditional medicines: Dan-shen root, Szechwan lovge rhizome, Chinese angelica, Hawthorn fruit, Safflower, Peach seed, Red peony root, earthworm, and membranous milkvetch root. These medicines are used to cure cardiovascular disease in China. METHODS: Animal models were established by feeding the Sprague-Dawley (SD) rats with lipid-rich forage. Serum total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) were measured. Malondialdehyde (MDA) content was determined to monitor lipid peroxidation. The 6-keto-prostaglandin F(1alpha)(6-keto-PGF(1alpha)) concentration was measured by radioimmunoassay to investigate the content of prostacyclin (PGI(2)). Electron microscope (JEM-1200EX) was used to observe the microstructure of the vascular endothelium. Rat aortic endothelial cell was cultured to investigate the effect of CVPM on vascular endothelial cell in vitro. RESULTS: CVPM inhibited the accumulation of TC, LDL-C, and MDA in vivo, when the rats were fed with cholesterol diet. CVPM promoted synthesizing and excreting of PGI(2), since it is capable of activating the proliferation of vascular endothelium in vitro. Electron micrographs showed that CVPM had notable protective effect on the vascular endothelium and prevented the shedding of these cells from subendothelial layer. CONCLUSIONS: CVPM could ameliorate the internal environment in which vascular endothelial cells lived, and activate the proliferation of these cells. Through these mechanisms, CVPM protect vascular endothelial cell from being harmed by excess cholesterol in vivo.