Simulation of water and nitrogen dynamics in soils during wastewater applications by using a finite-element model

A mathematical model was developed to simulate water movement, mass transport, and nitrogen transformations in soils during wastewater applications. The model is one-dimensional and based on the Galerkin finite-element method. The submodel of mass transport of nitrogen incorporates the convection-dispersion processes of ammonium and nitrate nitrogen, nitrification, denitrification, ammonium exchange and uptake of ammonium and nitrate ions. The accuracy and validity of the proposed model was examined by comparison with an explicit-implicit finite-difference model results. The model was used for simulation of water and nitrogen dynamics during wastewater application in homogeneous and multi-layered soils under different N concentration, rate, duration and scheduling of application.     

OPERATOR-SPLITTING METHOD FOR ANALYSIS OF CAVITATION IN LIQUID-LUBRICATED HERRINGBONE GROOVED JOURNAL BEARING

ＮＯＭＥＮＣＬＡＴＵＲＥｃ　ｒａｄｉａｌｃｌｅａｒａｎｃｅｈ　ｆｉｌｍｔｈｉｃｋｎｅｓｓ ｈ　ｄｉｍｅｎｓｉｏｎｌｅｓｓｆｉｌｍｔｈｉｃｋｎｅｓｓ (ｈ/ｃ)Ｌ/Ｄ　ｒａｔｉｏｏｆｌｅｎｇｔｈｔｏｄｉａｍｅｔｅｒｐ　ｆｉｌｍ ｐｒｅｓｓｕｒｅｅ　ｅｃｃｅｎｔｒｉ     

柯乌萨尔大坝施工中的灌浆工程

柯乌萨尔坝，位于伊朗南部哈拉巴德河上，为混凝土重力坝，坝高144．0m，坝顶长190m。坝基为石灰岩与尼灰质石灰岩厚互层，石灰岩在岩体内分布较为均匀，但具有众多小溶洞。简要介绍了该坝施工过程中的灌浆工程，灌浆帷幕和排水的参数根据工程地质钻探资料、空间渗流图的研究和灌浆试验结果确定。     

黄河水市场的建立与水资源的优化配置

1987年国务院批准了黄河可供水理分配方案，1994年黄河水利委员会又向沿黄省（区）颁发了《取水许可证》。随着流域社会经济的发展，黄河水资源供需矛盾愈加突出。目前黄河水资源管理调度体制还存在政府指令配水严重失控、没有引入激励补偿机制、同比例丰增枯减的原则不利于水资源优化配置等问题。在黄河上建立水市场符合市场经济规律，可以促进节水，提高水资源的利用率，改善生态环境，有利于水资源的高效配置和合理利用。     

Updating the Determinants of Firm Performance: Estimation using the 1998 UK Workplace Employee Relations Survey

We examine the determinants of establishment performance in the UK, using cross‐sectional data from the 1998 Workplace Employee Relations Survey to replicate research by Fernie and Metcalf (1995) who used data from the 1990 Workplace Employee Relations Survey; specifically, we test whether employee representation, contingent pay and efforts to boost employee participation affect a set of economic and industrial relations outcome indicators in the manner they suggest. We also re‐estimate the influential WERS90‐based study of Machin and Stewart (1996) on the links between union status and financial performance. In both cases we report very different results.     

Safety of Navigation Locks

The author's observations and studies of safety of navigation locks are described. A mathematical model of lock reliability and its graphical interpretation are presented. The possibility of determination of the accident risk level by processing statistical data is discussed.