Palladium nanoparticles supported on amine-functionalized glass fiber mat for fixed-bed reactors on the effective removal of hexavalent chromium by catalytic reduction

Palladium nanoparticles were deposited on the amine-grafted glass fiber mat (GFM-NH₂) catalyst support by a conventional impregnation process followed by the borohydride reduction in aqueous solution at room temperature to create the designed Pd/GFM-NH₂ catalyst. By the use of large size glass fiber mat without nano/mesopores as the catalyst support, the internal mass transfer limitations due to the existence of nano/mesopores on the catalyst support were eliminated and the Pd/GFM-NH₂ catalyst could be easily separated from treated water due to the large size of the catalyst support. Batch experiments demonstrate its good catalytic reduction performance of Cr(VI) with formic acid as the reducing agent. It also demonstrated an efficient Cr(VI) removal and stability in a lab-prepared, packed fixed-bed tube reactor for the continuous treatment of Cr(VI)-containing water. Thus, it has a good potential for the catalytic reduction of Cr(VI) in the water treatment practice.     

Development of predictive models for the estimation of the probability of suffering fear of falling and other fall risk factors based on posturography parameters in community-dwelling older adults

Falls pose an important problem for older adults. Balance training is one of the main prevention strategies, but there is a lack of objective measurement methods that would allow the effectiveness of the treatments employed to be assessed. This study aimed to analyse the relationship between posturographic parameters and risk factors associated with falling, including the fear of falling (FoF). Forty-one healthy community-dwelling older adults were surveyed on their perception of problems considered to be fall risk factors. Balance measurement with posturography was performed. The relationships between risk factors and falls and risk factors and posturography were analysed by means of cross-tabulation and logistic regression, respectively. Experimental results showed a significant relationship between some of the posturographic parameters and various fall risk factors. Stability limits were related to FoF, and results from the Romberg test with eyes closed with and without foam correlated with problems in kneeling/crouching. The results from the Romberg test with eyes closed and foam correlated with osteoarthritis. Equations were developed to estimate the probability of having such problems. In conclusion, posturography is useful for the estimation of fall risk conditions in relation to three important fall risk factors (FoF, osteoarthritis and problems in kneeling/crouching), and it could be used for targeting, training and studying progress after the use of different treatments.Relevance to industryPosturography can be used as an assessment tool to analyse the effects of those treatments aimed at preventing falls. Furthermore, the equations derived from our results can be used along with posturographic variables to assess patient progress.     

Declining phosphorus as a potential driver for the onset of Didymosphenia geminata mats in North American rivers

Didymosphenia geminata is a stalk‐forming diatom capable of creating thick benthic mats in low‐nutrient streams. There are two hypotheses to explain the rapid worldwide increase in occurrence of nuisance D. geminata mats: (a) Cells are spread among rivers and across broad ecoregions through natural and anthropogenic vectors, or (2) pre‐existing D. geminata populations are forming mats in response to changing environmental conditions within the habitat. Low phosphorus (P) concentrations are a major trigger for stalk production by D. geminata cells. Although the environmental change hypothesis is gaining support among researchers, long‐term data sets demonstrating declining P concentrations prior to reported mat formation have been essentially absent from the literature. Here, we present long‐term datasets for two case studies for which long‐term P and D. geminata data coincide: the Matapedia River in Eastern Canada and the Kootenai River below Libby Dam in Montana, United States. Both rivers had declining P levels over time. However, there was a 2‐ and 20‐year lag time, respectively, between mat development and reaching the previously proposed average 2 μg/L soluble reactive P threshold for development. Although the Matapedia River provides some support of the environmental change hypothesis, the Kootenai River data set suggests other environmental factors may play a role in mat development. The data presented do not rule out the environmental change hypothesis but do suggest there may be conditions in addition to low P that must be met for mats to form and the environmental change hypothesis can likely be refined to include more parameters to better understand and mitigate the influence of mats.     

生态护坡在辽宁省城市河道整治中的应用

简述了传统护坡治理中存在的问题,介绍了生态袋护坡、三维植被网护坡及稻草垫生物护坡在辽宁省河道治理中的应用,结合工程实例阐述了三种护坡形式的特点及实际应用中应注意的问题。     

水下崩岸段吨袋垫坡与膜袋自密实混凝土护坡施工技术应用与效果分析

河道的回水地带常年受河道水流迎流顶冲影响,岸坡冲刷严重易崩塌,影响岸坡安全。以涡河县义门镇涡河左堤崩岸段应急加固工程为例,采用吨袋垫坡+膜袋自密实混凝土护坡技术对崩岸段进行加固处理有效解决了水下护岸边坡因水流冲刷引起的变形与坍塌问题,效果良好,可为类似工程施工提供参考。     

低成本一次低温快烧生料无光釉的研制

以工业废渣为主要原料研制了低温一次快烧生料无光釉，分析探讨了废渣无光釉的化学组成和烧成条件，该釉不仅适于一次低温快烧工艺，而且可显著降低釉料成本，在墙地砖生产中有较大应用价值。     

一种全局指数收敛的摄像机内参数观测器

针对摄像机标定问题,本文从控制理论角度出发设计了一种具有指数收敛特性的摄像机内参数观测器.当摄像机随移动机器人等运动平台一起旋转时,该观测器使用其运动信息和实时拍摄得到的特征点图像信息,可以实现对摄像机内参数的在线估计.具体而言,论文分析了云台摄像机的运动约束,建立了特征点图像坐标变化的运动学模型,随后基于4个或4个以上特征点（其中任意3点不共线）,构造了一种内参数非线性观测器,并通过理论分析证明了其状态估计指数收敛于摄像机的相应内参数,仿真结果验证了这种非线性观测器的良好特性.     

非金属矿物纤维制作汽车尾气净化器衬垫的研究

采用与传统干法生产工艺不同的湿法造纸工艺，以非金属矿物纤维海泡石为主要纤维原料配加玻璃纤维、陶瓷纤维、有机纤维生产净化器衬垫．结果表明：以非金属矿物纤维海泡石为主要纤维原料制作的净化器衬垫具有较好的物理性能．     

Experimental Investigation of Load Settlement Behavior of Coir Mat and Coir Fiber Reinforced Sand

An experimental study in terms of model footing test were performed to comparatively assess the effect of form of reinforcement, viz., mat and fiber, on the load intensity response of reinforced sand. Coir reinforcement was used in this present investigation to assess comparative performance of coir mat and coir fiber reinforced sand, as it is highly durable among all other natural materials. Model footing test were conducted by placing coir mat and coir fiber at different u/B ratios. Load deformation behavior was compared with the help of peak strain, bearing capacity ratio and settlement reduction factor. The experimental and calculated theoretical values of peak stress of coir mat reinforced sand were compared and found that both the values were in good agreement with predicted values. The results of the present experimental investigation indicated that the form of reinforcement viz., mat/grid and fibers has significant influence on load deformation behavior of reinforced sand. Coir mat when located within the failure zone intercepting the shear zone below the loaded footing is most beneficial in terms of load carrying capacity of reinforced sand, in consistent with earlier investigations. However maximum increase in bearing capacity of coir fiber reinforced sand does indicate an optimum u/B ratio of 1.0. Maximum SRF for coir mat reinforced sand corresponds to u/B = 0.6 where for coir fiber reinforced sand it corresponds to u/B = 1.0.     

不同采样密度下体压分布特征

对压力座垫原始数据（采样密度为32×32）进行空域滤波处理剔除噪声，增强独立传感器之间数据分布的连续性. 将体压分布采样密度降至24×24、16×16、8×8，提取不同采样密度下的平均压力、峰值压力、平均压力梯度和峰值压力梯度进行分析. 单因素方差分析结果表明，32×32采样密度与24×24、16×16采样密度下的特征均值之间的差异较小（1.1、2.6 mmHg），与8×8采样密度下的特征均值之间的差异较大（9.0 mmHg）. 斯皮尔曼相关性分析结果表明，32×32与24×24、16×16、8×8采样密度下的平均压力、峰值压力、平均压力梯度和峰值压力梯度具有较高的相关性（P<0.05）. 其中相关性最高的为与24×24采样密度下的峰值压力（0.99，P<0.05），相关性最低的为与8×8采样密度下的平均压力梯度（0.55，P<0.05）. 试验结果表明采样密度为24×24和16×16的压力座垫可以提供精确的体压分布特征.