Design of Circular Urban Storm Sewer Systems Using Multilinear Muskingum Flow Routing Method

In this study, a multilinear Muskingum method is presented for hydrologic routing through circular conduits. In order to increase accuracy, the reference discharge is assumed to be a nonlinear function of conduit diameter, Manning coefficient, bed slope, and peak discharge of the inflow hydrograph. The reference discharge function has been determined using a nonlinear regression technique. Flow depths are computed at every time step by solving the continuity equation using an implicit finite difference scheme. Many storm hydrographs were routed through circular conduits of various sizes by the proposed model. The calculated routed hydrographs and water surface profiles indicate close agreement with those obtained by solving Saint Venant equations. Using this method, a branched urban sewer system was designed. This indicates that the method can be easily implemented for design purposes because of its simplicity, accuracy, and computational efficiency.     

A CONTRIBUTION TO THE PREDICTION OF PHASE SEPARATION IN BRANCHING CONDUITS

A phenomenological model for phase separation in branching conduits (Hwang el al., 1988) has been extended and improved. These modifications involve new models for the phase distribution at the inlet of a branching junction corresponding to four different flow regimes, and a correction for flooding in vertical junctions. This mechanistically-based model gives good agreement when compared with representative experimental data.     

Advances and Future Applications of Augmented Peripheral Nerve Regeneration

Peripheral nerve injuries remain a significant source of long lasting morbidity, disability, and economic costs. Much research continues to be performed in areas related to improving the surgical outcomes of peripheral nerve repair. In this review, the physiology of peripheral nerve regeneration and the multitude of efforts to improve surgical outcomes are discussed. Improvements in tissue engineering that have allowed for the use of synthetic conduits seeded with neurotrophic factors are highlighted. Selected pre-clinical and available clinical data using cell based methods such as Schwann cell, undifferentiated, and differentiated stem cell transplantation to guide and enhance peripheral nerve regeneration are presented. The limitations that still exist in the utility of neurotrophic factors and cell-based therapies are outlined. Strategies that are most promising for translation into the clinical arena are suggested.     

Human IL12p80 Promotes Murine Oligodendrocyte Differentiation to Repair Nerve Injury

Nerve injury of the central nervous system and the peripheral nervous system still poses a major challenge in modern clinics. Understanding the roles of neurotrophic factors and their molecular mechanisms on neuro-regeneration will not only benefit patients with neural damage but could potentially treat neurodegenerative disorders, such as amyotrophic lateral sclerosis. In this study, we showed that human IL12 p40-p40 homodimer (hIL12p80) within PLA and PLGA conduits improved sciatic nerve regeneration in mice. As such, the group of conduits with NSCs and hIL12p80 (CNI) showed the best recovery among the groups in the sciatic functional index (SFI), compound muscle action potential (CMAP), and Rotarod performance analyses. In addition, the CNI group had a faster recovery and outperformed the other groups in SFI and Rotarod performance tests beginning in the fourth week post-surgery. Immunohistochemistry showed that the CNI group increased the diameter of the newly regenerated nerve by two-fold (p < 0.01). In vitro studies showed that hIL12p80 stimulated differentiation of mouse NSCs to oligodendrocyte lineages through phosphorylation of Stat3 at Y705 and S727. Furthermore, implantation using PLGA conduits (C2.0 and C2.1) showed better recovery in the Rotarod test and CMAP than using PLA conduits in FVB mice. In B6 mice, the group with C2.1 + NSCs + hIL12p80 (C2.1NI) not only promoted sciatic functional recovery but also reduced the rate of experimental autotomy. These results suggested that hIL12p80, combined with NSCs, enhanced the functional recovery and accelerated the regeneration of damaged nerves in the sciatic nerve injury mice. Our findings could further shed light on IL12′s application not only in damaged nerves but also in rectifying the oligodendrocytes’ defects in neurodegenerative diseases, such as amyotrophic lateral sclerosis and multiple sclerosis.     

大型给水泵站进、出水流道数值模拟及优化设计

根据某给水泵站设计参数要求,设计具有相同进、出口尺寸的肘型和簸箕型2种进水流道方案,以及7种不同龟背形式和倒圆弧半径的出水流道方案。数值计算采用压强连接的隐式修正SIMPLEC算法,并结合雷诺平均法的RNGκ-ε模型和壁面函数法。计算结果表明,在相同进、出口尺寸条件下,肘型进水流道的水力损失比簸箕型进水流道小73.7%;有龟背和圆弧的出水流道的水力损失最小。该研究实现了进、出水流道的优化设计。     

玻璃纤维增强塑料（FRP）电缆导管的载流量变化计算

电缆导管的载流量是一个重要的使用技术指标,进行一次电缆导管的载流量试验要化很大的财力和人力。本文在对PVC电缆导管已做过的试验基础上,对玻璃纤维增强塑料电缆导管（FRP电缆导管）的载流量进行理论计算,得出FRP电缆导管的电缆载流量的计算公式,理论计算证明：对于PVC导管理论计算与实验数据很符合,FRP电缆导管的电缆载流比PVC管略高0.6％-1.8％。本文从载流量角度出发,进一步说明FRP电缆导管比传统导管、PVC导管等更加优越。     

内衬钢环加固深埋钢筋混凝土管

介绍了某深埋钢筋混凝土排水管的破坏情况 ,分析了破坏原因 ,并结合工程的实际情况 ,经对比分析 ,采用内衬钢环对其进行加固处理。同时介绍了施工和防护方法。实践证明所采用的钢环加固法达到了预期的目的 ,取得了很好的经济和技术效果     

基于BP的燃气管道评估专家系统设计与实现

BP神经网络具有并行处理、自适应学习、容错能力好等优点,根据地下燃气管道安全评估的应用要求,对其算法进行改进,结合专家系统的设计思路,构造了一个基于BP神经网络的地下燃气管道安全评估专家系统,包括知识表示、知识荻取和推理解释等模块.然后利用已有的样本编制软件进行实验,结果表明,该系统评估正确率达91%,推理效率高、扩展性好,从而很好地满足了实际应用的要求.神经网络为专家系统的发展提供了一条新的途径.     

油气输导体系研究述评

油气输导体系一直是石油地质学研究中的核心和难点。国内对于输导体系的研究始于20世纪90年代中后期。由于相关基础理论尚不完善,对于输导体系的研究仍为油气成藏机理研究的一个薄弱环节。目前,输导体系尚未具有统一的定义和分类方案,文中将其定义为油气从烃源岩运移到圈闭的过程中,各种潜在或已知的油气输导体的三维几何形态、内部构成、流体输导能力综合以及不同输导体的空间配置形式和时间上与生油期的匹配关系。并将油气输导体系分为两大类、6种类型。     

Aqueduct Management Planning: Thirlmere, Haweswater and Vyrnwy Aqueducts

Between 1988 and 1992, an asset study of North West Water Limited's three largest aqueducts was carried out to assess their condition and rehabilitation needs. About 360 km of the aqueduct system, including approximately 1700 structures, 160 km of tunnel and conduit, 700 km of pipeline and 4000 valves, were covered by the study. A wide range of survey techniques was used, some being specially developed as part of the study, and a unified system of condition assessment and prioritization of rehabilitation needs was devised.
The paper (a) describes the overall approach and survey techniques, (b) discusses the methods of assessment used, (c) summarizes the conditions of the assets whose ages vary from 20–100 years, and (d) reviews some of the rehabilitation works proposed and executed.