1,682 research outputs found

    Impact of Sucrose Addition on the Physiochemical Properties and Volatile Compounds of “Shuangyou” Red Wines

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    “Shuangyou,” a Vitis amurensis Rupr. variety, is widely cultivated in northeastern and western China. Its berries have high acidity and low sugar content. In this study, different proportions of sucrose were added to the must samples during fermentation to investigate the effect of sugar on the physicochemical properties and volatile compounds of “Shuangyou” wines. The addition of sucrose significantly improved yeast growth and alcohol production, altered the color qualities, and slightly decreased titratable acidity during fermentation. The highest tested proportion of added sucrose resulted in the highest maximum yeast counts and final ethanol concentrations. Moreover, 37 volatile compounds (esters, alcohols, fatty acids, ketones, and aldehydes) were identified and quantified by solid-phase microextraction with gas chromatography-mass spectrometry. The concentrations of these compounds were correlated with the addition of sucrose. Furthermore, the addition of 100 g/L sucrose was sufficient for improving the concentrations of the aromatic compounds. The increase in ester, alcohol, and fatty acid concentration led to a positive OAVs impact (odor activity value > 1) at the end of fermentation

    MVF-Net: Multi-View 3D Face Morphable Model Regression

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    We address the problem of recovering the 3D geometry of a human face from a set of facial images in multiple views. While recent studies have shown impressive progress in 3D Morphable Model (3DMM) based facial reconstruction, the settings are mostly restricted to a single view. There is an inherent drawback in the single-view setting: the lack of reliable 3D constraints can cause unresolvable ambiguities. We in this paper explore 3DMM-based shape recovery in a different setting, where a set of multi-view facial images are given as input. A novel approach is proposed to regress 3DMM parameters from multi-view inputs with an end-to-end trainable Convolutional Neural Network (CNN). Multiview geometric constraints are incorporated into the network by establishing dense correspondences between different views leveraging a novel self-supervised view alignment loss. The main ingredient of the view alignment loss is a differentiable dense optical flow estimator that can backpropagate the alignment errors between an input view and a synthetic rendering from another input view, which is projected to the target view through the 3D shape to be inferred. Through minimizing the view alignment loss, better 3D shapes can be recovered such that the synthetic projections from one view to another can better align with the observed image. Extensive experiments demonstrate the superiority of the proposed method over other 3DMM methods.Comment: 2019 Conference on Computer Vision and Pattern Recognitio

    Investigation of Properties Alternation during Super-Critical CO2 Injection in Shale

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    The low recovery of oil from tight liquid-rich formations is still a major challenge for a tight reservoir. Thus, supercritical CO2 flooding was proposed as an immense potential recovery method for production improvement. While up to date, there have been few studies to account for the formation properties\u27 variation during the CO2 Enhanced Oil Recovery (EOR) process, especially investigation at the micro-scale. This work conducted a series of measurements to evaluate the rock mechanical change, mineral alteration and the pore structure properties\u27 variation through the supercritical CO2 (Sc-CO2) injection process. Corresponding to the time variation (0 days, 10 days, 20 days, 30 days and 40 days), the rock mechanical properties were analyzed properly through the nano-indentation test, and the mineralogical alterations were quantified through X-ray diffraction (XRD). In addition, pore structures of the samples were measured through the low-temperature N2 adsorption tests. The results showed that, after Sc-CO2 injection, Young\u27s modulus of the samples decreases. The nitrogen adsorption results demonstrated that, after the CO2 injection, the mesopore volume of the sample would change as well as the specific Brunauer-Emmett-Teller (BET) surface area which could be aroused from the chemical reactions between the CO2 and some authigenic minerals. XRD analysis results also indicated that mesopore were altered due to the chemical reaction between the injected Sc-CO2 and the minerals

    One-step method to prepare starch-based superabsorbent polymer for slow release of fertilizer

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    Here we report the use of a one-step process of reactive melt mixing to prepare starch-based superabsorbent polymers (SBSAPs) for the slow release of urea as a fertilizer. A modified twin-rotor mixer, with improved sealing to establish an oxygen-free environment, was used to study the chemical and physical reactions during the melt-processing through monitoring the temperature and torque. The effects of the initiator (ceric ammonium nitrate, or CAN), crosslinker (N,N′-methylene-bisacrylamide, or N,N′-MBA) and saponification agent (NaOH) under different reaction conditions (time, temperature, and shear intensity) were systematically studied. Also investigated was the effect of starch with different amylose content. Fourier-transform infrared (FTIR) spectroscopy and thermogravimetric analysis (TGA) confirmed that using this simple technique, SBSAPs were successfully prepared from either high-amylopectin starch (waxy corn starch) or high-amylose starch (Gelose 50) grafted with AM and crosslinked by N,N′-MBA. Gel strength was evaluated by rheometry, which revealed a significant increase in storage modulus (G′) obtained in the crosslinked high-amylose SBSAP gels. Also, scanning electron microscopy (SEM) images showed a more sophisticated structural network with a smaller pore size in the crosslinked high-amylose gels. Urea as a fertilizer was embedded in the SBSAP gel network, and this network controlled the urea release in water. The release rate of urea depended on the gel strength, gel microstructure and water absorption capacity (WAC) of SAP, which was affected by the reaction conditions and degree of saponification
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