Rapid screening of DON contamination in whole wheat meals by Vis/NIR spectroscopy and computer vision coupling technology

This work intends to develop an online experimental system for screening of deoxynivalenol (DON) contamination in whole wheat meals by visible/near-infrared (Vis/NIR) spectroscopy and computer vision coupling technology. Spectral and image information of samples with various DON levels was collected at speed of 0.15 m s⁻¹ on a conveyor belt. The two-type data were then integrated and subjected to chemometric analysis. Discriminant analysis showed that samples could be classified by setting 1000 μg kg⁻¹ as the cut-off value. The best correct classified rate obtained in prediction was 93.55% based on fusion of spectral and image features, with reduced prediction uncertainty as compared to single feature. However, quantification of DON by quantitative analysis was not successful due to poor model performance. These results indicate that, although not accurate enough to provide conclusive result, this coupling technology could be adopted for rapid screening of DON contamination in cereals and feeds during processing.     

新型格栅支撑有序堆积床内流动传热数值研究

颗粒堆积床作为反应器和分离器等的重要组成广泛应用于实际化学工业生产中。基于传统的有序堆积结构，提出了一种新型格栅支撑有序堆积结构，通过采用新型格栅支撑结构可以快速构建有序颗粒堆积床，其中包括格栅支撑简单立方、格栅支撑体心立方、格栅支撑疏松面心立方和格栅支撑密实面心立方颗粒堆积结构。对4种颗粒堆积单元通道内的流动换热进行模拟研究后发现，不同堆积形式的格栅支撑颗粒堆积床流动换热性能不同；在相同的面心立方堆积形式下，使用不同的格栅支撑结构，其流动传热也有明显差异；与传统有序堆积结构相比，在换热相差不多的情况下，格栅支撑有序堆积结构的压降减小，所以其综合换热效率有明显提升。     

吸收烟气中低浓度CO2的操作条件分析

Mg(OH)2浆液是一种具备低再生能耗潜力的CO2吸收剂，为了推进其在CO2捕集领域的应用而展开研究。在填料塔中，使用真实烟气研究了各种操作条件下Mg(OH)2浆液对CO2的捕集效率。研究发现,填料种类、气体名义停留时间、液气比均对CO2捕集效率有影响。结果表明，增加气体名义停留时间无法有效改善液相传质，而提高液气比能够有效改善液相传质；在试验条件下，拉西环、鲍尔环和IMTP的总体积传质系数分别为8.5×10-7～5.0×10-6、1.8×10-6～4.0×10-6和1.9×10-7～2.9×10-6 mol/(m3·s·Pa)。     

Thermodynamic Analysis of Packed Bed Thermal Energy Storage System

A packed-bed thermal energy storage(PBTES) device, which is simultaneously restricted by thermal storage capacity and outlet temperatures of both cold and hot heat transfer fluids, is characterized by an unstable operation condition, and its calculation is complicated. To solve this problem, a steady thermodynamics model of PBTES with fixed temperatures on both ends was built. By using this model, the exergy destruction, thermocline thickness, thermal storage capacity, thermal storage time, and other key parameters can be calculated in a simple way. In addition, the model explained the internal reason for the change of thermocline thickness during thermal storage and release processes. Furthermore, the stable operation of the PBTES device was analyzed, and it was found that higher inlet temperature of hot air, and lower temperature difference between cold and hot air can produce less exergy destruction and achieve a larger cycle number of stable operation. The work can be employed as the basis of the design and engineering application of PBTES.     

A review on thermal energy storage systems in solar air heaters

The drying needs of agricultural, industrial process heat requirements and for space heating, solar energy is one of the prime sources which is renewable and pollution free. As the solar energy is inconsistent and nature dependent, more often there is a mismatch between the solar thermal energy availability and requirement. This drawback could be addressed to an extent with the help of thermal energy storage systems combined with solar air heaters. This review article focuses on solar air heaters with integrated and separate thermal energy storage systems as well as greenhouses with thermal storage units. A comprehensive study was carried out in solar thermal storage units consisting of sensible heat storage materials and latent heat storage materials. As the phase change heat storage materials offer many advantages over the sensible heat storage materials, the researchers are more interested in this system. The charging and discharging characteristics of thermal storage materials with various operational parameters have been reported. All the possible solar air heater applications with storage units have also been discussed.     

Atom transfer radical polymerization (ATRP): A versatile and forceful tool for functional membranes

The progress in atom transfer radical polymerization (ATRP) provides an effective means for the design and preparation of functional membranes. Polymeric membranes with different macromolecular architectures applied in fuel cells, including block and graft copolymers are conveniently prepared via ATRP. Moreover, ATRP has also been widely used to introduce functionality onto the membrane surface to enhance its use in specific applications, such as antifouling, stimuli-responsive, adsorption function and pervaporation. In this review, the recent design and synthesis of advanced functional membranes via the ATRP technique are discussed in detail and their especial advantages are highlighted by selected examples extract the principles for preparation or modification of membranes using the ATRP methodology.     

Separation and determination of cadmium in water by foam column prior to inductively coupled plasma optical emission spectrometry

The sorption profile of cadmium (II) ions from aqueous iodide media onto procaine hydrochloride (PQ⁺·Cl⁻) treated polyurethane foams (PUFs) solid sorbent was studied. PQ⁺·Cl⁻ treated PUFs solid sorbent was found suitable and fast for Cd²⁺ uptake as [CdI4]_aq²⁻. Thus, removal of Cd²⁺ at trace levels by the sorbent packed columns was achieved. The sorbed Cd²⁺ species onto packed column were recovered with HNO₃ (10.0 mL, 1.0 mol L⁻¹) prior determination by inductively coupled plasma-optical emission spectrometry (ICP-OES). Plot of Cd²⁺ ions concentration was linear in the range 0.05–15 μg L⁻¹. The limits of detection and quantification of Cd²⁺ were found 0.01 μg L⁻¹ and 0.033 μg L⁻¹, respectively. Such limits could be improved to lower values by retention of Cd²⁺ species from large sample volumes of the aqueous phase at the optimized conditions. The relative standard deviation of the packed column for the extraction and recovery of standard aqueous solutions (0.1 L) containing 1.0 and 5.0 μg L⁻¹ (n = 3) of Cd²⁺ ions at flow rate of 5.0 mL min⁻¹ were 1.98 and 2.9%, respectively. The method was validated by analysis of Cd in certified reference materials (CRMs) IAEA-Soil-7 and TMDW water and wastewater samples.     

Biological sulphate removal in an upflow packed bed reactor

Mine waters and industrial effluents with high sulphate concentrations create a disposal problem in terms of excess mineralization of surface waters. Removal of sulphate can be achieved by various processes including biological techniques, all of which involve appreciable costs. The purpose of this investigation was to improve on known biological methods for the removal of sulphate. Good sulphate removal was obtained by providing anaerobic conditions on a solid medium and maintaining a low hydrogen sulphide concentration by recirculating the water through a photosynthetic reactor for sulphur production.     

Research and development of advanced structured packing in a rotating packed bed

As the core component of the rotating packing bed, packing is a place for efficient gas–liquid mixing and mass transfer. In this paper, a 3D structured packing composed of a mesh structure and a support structure was designed. The mesh structure is a ring-shaped mesh surrounded by triangular meshes, which is stable in structure and can achieve a high degree of dispersion and aggregation of the liquid phase. The support structure is composed of ring-shaped structural units arranged at a certain angle along the axial direction, which can enhance the turbulence of the airflow while constructing regular gas-phase channels. Circumferential steel meshes of different diameters and supporting structures are alternately combined to form 3D packing, which is loaded in a layered cross-flow rotating packing bed. The results show that under the same operating conditions, the mass transfer performance of 3D packing and wire mesh packing are equivalent, and both are better than pall ring packing. Moreover, the pressure drop of 3D packing is significantly lower than that of pall ring packing and wire mesh packing. The design and implementation of packing the development presented in this paper can be used to develop special structured packing for rotating bed, which can further improve the performance of rotating packed bed (RPB).