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101.
Large scale open cut coal mining operations have significant impacts to groundwater in surrounding areas in both active and post-mining phases. The prediction of water inflows into a surface mine excavation is one of the many components involved in mine design phase. Groundwater performance also reacts to mining activities from the operational, economic and safety implications perspective. Under NSW planning legislation, as part of the comprehensive risk assessment, a groundwater impact assessment has to be conducted for a coal project to predict and mitigate the impacts in consideration of the government requirements. In this paper, the groundwater assessment modelling of mine pits was discussed in predicting of groundwater inflows and reviewing analytical and numerical approaches. A methodology of groundwater impact assessment for an open cut mine in NSW with a three-dimensional groundwater flow model Modflow Surfact demonstrated its functions in simulating the project's impacts on the groundwater regime. The key findings with mitigations are discussed and recommended in the paper to reduce impacts on groundwater and fulfil regulation requirements in NSW.  相似文献   
102.
MODELLINGOFP/MFORMINGPROCESSESBYFEM¥Wei,Yuanping;Ruan,Xueyu(DepartmentofPlasticityTechnology,ShanghaiJiaoTongUniversity,Shang...  相似文献   
103.
A functional approach for the formalization of the fixture design process   总被引:1,自引:0,他引:1  
The design of machining fixtures is a highly complex process that relies on designer experience and his/her implicit knowledge to achieve a good design. In order to facilitate its automation by the development of a knowledge-based application, the explicit definition of the fixture design process and the knowledge involved is a prior and a fundamental task to undertake. Additionally, a fundamental and well-known engineering principle should be considered: the functional requirements and their associated constraints should be the first input to any design process. Considering these two main ideas, this paper presents the development undertaken to facilitate the automation of the fixture design process based on a functional approach.In this context, the MOKA methodology has been used to elicit fixtures knowledge. IDEF0 and UML have been used to represent the fixture design process. A methodology based on the function concept and aiming to formalize such design process is proposed. Fixture functional requirements have been defined and formalized. Functional fixtures elements have been used to create a functional design solution, the link of these elements with the functional requirements and with typical commercial fixture components has been defined via tables and rules mapping. And finally, a prototype knowledge-based application has been developed in order to make an initial validation of the proposed methodology.  相似文献   
104.
T  Bell  Y  Su  H.Dong  石常亮 《中国表面工程》2007,20(2):1-10
在任何严峻条件下现代机械运行中综合性能的迫切需求促进了许多先进表面工程技术的迅速发展。因而,设计者在结构设计时将有许多表面工程技术可以选择。但是,怎样为一种特定的应用选择一种最优化的表面工程方法对设计者来说又是一种挑战。为了这个目标,在现代多层表面接触理论的基础上建立起一种接触力学模型,考虑到了多层结构、真实表面粗糙度和摩擦影响。这种力学模型可以成功地预测表面工程结构的性能。文中首先回顾了赫兹接触理论的发展过程,然后讨论了伯明翰多层真实粗糙表面接触力学模型,并用实例示范了一系列关于动载荷下表面工程结构设计的主要步骤。  相似文献   
105.
This paper describes the development, comparison and validation of both 2-D and 3-D models of the electroplating process in which the current density distribution, generated using the Finite Element Method (FEM), is used together with Faraday's law of electrolysis to determine the local plating depth. Prior to work on industrial components, a preliminary investigation was undertaken on the electroplating of a square copper cathode (work piece) with a parallel lead anode of identical shape. The results described here show good agreement, particularly in 3-D and are considered to validate the model sufficiently for it to be used for electroplating tooling design.  相似文献   
106.
Global demand for freshwater has led to unprecedented levels of water abstraction from riverine systems. This has resulted in large alterations in natural river flows. The deleterious impacts of reduced flows on fish and macroinvertebrate abundances have been thoroughly investigated; in contrast, there is a limited understanding of the potential for changes in the abundance of nuisance benthic algal/cyanobacterial blooms. In New Zealand, Phormidium sp. blooms are common in numerous rivers during summer low flows. In this study, an in‐stream habitat assessment is used to examine the relationship between Phormidium habitat availability and reducing flows. Over 650 observations of Phormidium mats, from seven sites (Hutt River, lower North Island, New Zealand), were used to construct habitat suitability curves for depth, velocity and substrate. Preference curves were fitted using both the ‘forage ratio’ and ‘quantile regression’ methods. Phormidium growth, observed at all seven sites, increased significantly from upstream (uppermost site, 5.2% mat cover) to downstream (63.5%). The habitat suitability curves revealed Phormidium had a large tolerance to velocity, depth and substrate type. Consequently, decreases in flow had only negligible effects on available Phormidium habitat. During periods of stable flow, Phormidium abundance positively correlated with increased nitrogen concentrations, potentially explaining the large variation in Phormidium cover from upstream to downstream. Quantile regression generated habitat suitability criteria were a more accurate predictor of available Phormidium habitat than the forage ratio criteria. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   
107.
The challenges of machining, particularly milling, glass fibre-reinforced polymer (GFRP) composites are their abrasiveness (which lead to excessive tool wear) and susceptible to workpiece damage when improper machining parameters are used. It is imperative that the condition of cutting tool being monitored during the machining process of GFRP composites so as to re-compensating the effect of tool wear on the machined components. Until recently, empirical data on tool wear monitoring of this material during end milling process is still limited in existing literature. Thus, this paper presents the development and evaluation of tool condition monitoring technique using measured machining force data and Adaptive Network-Based Fuzzy Inference Systems during end milling of the GFRP composites. The proposed modelling approaches employ two different data partitioning techniques in improving the predictability of machinability response. Results show that superior predictability of tool wear was observed when using feed force data for both data partitioning techniques. In particular, the ANFIS models were able to match the nonlinear relationship of tool wear and feed force highly effective compared to that of the simple power law of regression trend. This was confirmed through two statistical indices, namely r2 and root mean square error (RMSE), performed on training as well as checking datasets.  相似文献   
108.
Sustainable management of groundwater-dependent vegetation (GDV) requires the accurate identification of GDVs, characterisation of their water use dynamics and an understanding of associated errors. This paper presents sensitivity and uncertainty analyses of one GDV mapping method which uses temperature differences between time-series of modelled and observed land surface temperature (LST) to detect groundwater use by vegetation in a subtropical woodland. Uncertainty in modelled LST was quantified using the Jacobian method with error variances obtained from literature. Groundwater use was inferred where modelled and observed LST were significantly different using a Student's t-test. Modelled LST was most sensitive to low-range wind speeds (<1.5 m s−1), low-range vegetation height (<=0.5 m), and low-range leaf area index (<=0.5 m2 m−2), limiting the detectability of groundwater use by vegetation under such conditions. The model-data approach was well-suited to detection of GDV because model-data errors were lowest for climatic conditions conducive to groundwater use.  相似文献   
109.
NURBS (non-uniform rational b-spline) modelling has become a ubiquitous tool within architectural design praxis. In this article I examine three projects that utilise NURBS modelling as a means for which a musical system's inherent spatiality is visualised. There are numerous precedents for which architectural form is a derivation of a musical system, or a musical system is proportionally informed by architectonic gesture. I propose in this article three NURBS modelling methodologies: for the spatial analysis of Karlheinz Stockhausen's sound projection geometries in Pole für 2; for a spatial realisation of John Cage's indeterminate work Variations III; and for the generation of a surface manifold informed by musically derived soundscape data from the Japanese garden Kyu Furukawa Teien. Rather than seeking to translate music into inhabitable architecture, or architectonic form into music, I highlight an approach that produces an interstitial territory between discourses on architecture and music analysis.  相似文献   
110.
As changes in landuse and the demand for water accelerate, regulators and resource managers are increasingly asked to evaluate water allocation against the need for protection of in‐stream habitat. In the United States, only a small number of river basins have the long‐term hydrograph data needed to make these assessments. This paper presents an example of how to bridge the conceptual and physical divide between GIS‐based watershed modelling of basin‐discharge and in‐stream hydraulic habitat models. Specifically, we used a Soil and Water Assessment Tool (SWAT) model for the Hillsborough River to produce data for use in a Physical HABitat SIMulation (PHABSIM) model of the same river. This coupling of models allowed us to develop long‐term discharge data in ungauged river systems based on watershed characteristics and precipitation records. However this approach is not without important limitations. Results confirm that accuracy of the SWAT‐predicted hydrograph declines significantly when either the DEM resolution becomes too coarse or if DEM data are resampled to a coarser or finer resolution. This is due to both changes in the size and shape of the river basin with the varying DEMs and subsequent shifts in the proportions of land use, soils and elevation. Results show the use of 30 m DEMs produced hydrographic patterns amenable for using in‐stream habitat protocols like PHABSIM model, especially where little or no hydrographic and land use information exists. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   
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