Effect of Coconut, Sisal and Jute Fibers on the Properties of Starch/Gluten/Glycerol Matrix

Coconut, sisal and jute fibers were added as reinforcement materials in a biodegradable polymer matrix comprised of starch/gluten/glycerol. The content of fibers used in the composites varied from 5% to 30% by weight of the total polymers (starch and gluten). Materials were processed in a Haake torque rheometer (120 °C, 50 rpm) for 6 min. The mixtures obtained were molded by heat compression and further characterized. Addition of lignocellulosic fibers in the matrix decreased the water absorption at equilibrium. The diffusion coefficient decreased sharply around 5% fiber concentration, and further fiber additions caused only small variations. The thermogravimetric (TG) analysis revealed improved thermal stability of matrix upon addition of fibers. The Young’s modulus and ultimate tensile strength increased with fiber content in the matrix. The storage modulus increased with increasing fiber content, whereas tanδ curves decreased, confirming the reinforcing effect of the fibers. Morphology of the composites analyzed under the scanning electron microscope (SEM) exhibited good interfacial adhesion between the matrix and the added fibers. Matrix degraded rapidly in compost, and addition of increased amounts of coconut fiber in the matrix caused a slowdown the biodegradability of the matrix. Names are necessary to report factually on available data; however, the USDA neither guarantees nor warrants the standard of the product, and the use of the name by USDA implies no approval of the product to the exclusion of others that may be suitable.     

Three-Dimensional Modeling of an Urban Park and Trees by Combined Airborne and Portable On-Ground Scanning LIDAR Remote Sensing

In this study, we confirmed the utility of airborne and portable on-ground scanning light detection and ranging (LIDARs) for three-dimensional visualization of an urban park and quantification of biophysical variables of trees in the park. The digital canopy height model (DCHM) and digital terrain model generated from airborne scanning LIDAR data provided precise images of the ground surface and individual tree canopies. The heights of 166 coniferous and broadleaf trees of 11 species in the park were estimated from the DCHM images with slight underestimation (mean error = −0.14 m, RMSE = 0.30 m). Portable on-ground scanning LIDAR provided images of individual trees with detailed features. Tree height and trunk diameter were estimated to be within 0.31 m and 1 cm, respectively, from the on-ground LIDAR images. We combined airborne and on-ground LIDAR images to overcome blind regions and created a complete three-dimensional model of three standing trees. The model allowed not only visual assessment from all viewpoints but also quantitative estimation of canopy volume, trunk volume, and canopy cross-sectional area.     

高效除磷材料的除磷特性研究

研究了高效除磷材料(Efficient Phosphorus Removal Composite,EPRC)的除磷特性,以及以此材料为填料的吸附柱对模拟含磷废水的除磷效果.试验结果表明: EPRC颗粒在15℃、25℃、35℃时的最大饱和吸附量分别达到1.9535mg/g、2.281mg/g、3.6724mg/g.以EPRC颗粒填充吸附柱处理模拟含磷废水时,停留时间8h、连续进水、运行8d,磷的平均去除率为93%,废水pH值略有升高.     

公路路基病害类型及处治对策

以京福线余州绕城高速公路东段为例,对公路工程建设中常出现的公路略基不良地质病害进行论述,并对这些不良地质害提出了相应的防治对策。     

大型海洋平台基础结构有限元分析

某大型海洋平台基础采用平台板 桩基础组合形式,承台面为椭圆形,台面尺寸为147.6m×99.0 m,平台板为混凝土板和钢梁组成的叠合梁板结构.该工程地处世界三大强潮海湾之一,所受荷载与当地地质条件均较复杂.介绍了应用有限元对其进行结构分析的实施方法及过程,采用弹性抗力法考虑了桩-土共同作用,重点探讨了钢梁加混凝土厚板组成的叠合梁的有限元模拟方法.通过对比分析,提出了计算结果精度高、可操作性强的叠合梁有限元模拟方案.有限元分析结果表明,该平台钢管混凝土桩与钢梁均满足材料强度要求,但在施工阶段,桩内存在拉力.     

Fungal-modification of Natural Fibers: A Novel Method of Treating Natural Fibers for Composite Reinforcement

Growing interest in green products has provided fresh impetus to the research in the field of renewable materials. Plant fibers are not only renewable but also light in weight and low in cost. Polymer composites manufactured using them find applications in diverse fields such as automobiles, housing, and furniture. However, their hydrophilic nature and inadequate adhesion with matrix limits their use in high performance applications. In this study, a novel method for improving adhesion characteristics of natural fibers has been developed. This method is carried out by treating hemp fibers with a fungus: Ophiostoma ulmi, obtained from elm tree infected with Dutch elm disease. Treated fibers showed improved acid–base characteristics and resistance to moisture. Improved acid–base interactions between fiber and resin are expected to improve the interfacial adhesion, whereas improved moisture resistance would benefit the durability of the composites. Finally, composites were prepared using untreated/treated fibers and unsaturated polyester resin. Composites with treated fibers showed slightly better mechanical properties, which is most probably due to improved interfacial adhesion.     

地下水渗流沉降的三维耦合模型及程序的研制

研制可合理模拟预测基坑降水过程中引起地面沉降的计算机程序,并提出最优化降水方案.基于三维全耦合数值模型,笔者开发了GWS软件.GWS软件是以比奥固结理论为基础,将土体的非线性特征及土的渗透性随应力状态的动态变化考虑进去,通过耦合地下水渗流场和土体应力场进行模拟预测基坑降水过程中渗流场及地面沉降的变化.以一个实际基坑降水工程为例,经GWS软件计算得出5口井联合抽水方案,后续工程证明此方案正确、可靠.以三维全耦合数值理论为基础的GWS软件,可以为基坑降水工程引起的地下水渗流场变化及地面沉降量提供可靠的预测.     

复合过滤法处理生物质焦油废水技术的研究

采用"复合过滤法"处理生物质焦油废水,通过分析生物质焦油废水水质特点,筛选出滤料的种类、确定滤料的配置比,并经实验对比分析。结果表明,经复合过滤法处理后的焦油废水COD、焦油、SS的去除率分别达到54%、60%、68%。该技术工艺简单,运行成本低,管理方便,可广泛用于农村生物质气化站的焦油废水处理。     

江宁区生态文明建设的实践与思考

南京市江宁区通过优化产业结构、提升环境治理、构筑生态新城等举措,打牢生态文明建设的现实基础。但对照国家生态文明示范区标准,在经济、社会、制度方面仍存在诸多制约因素。为此需逐步确立以科学规划为先导,以制度建设为根本,以产业转型为抓手,以乡村建设为载体,以生态德育为基点的生态文明建设思路。     

基坑放坡安全开挖的设计与施工

放坡开挖适用于地基土质较好、开挖深度不深,以及施工现场有足够放坡场所的工程。本文讨论了软土基坑施工中,当开挖不深(3～5m)、基坑开挖对周边工程环境要求不高或有可靠措施时采用放坡开挖的技术参数,列举了工程实例。