Evaluation of internal surface roughness in fiberglass pipes by surface roughness instruments

Abstract Introduction: Investigation of the internal surface roughness of fluid transmission systems pipes is very important in the amount of energy loss. Different concepts and methods have been used to examine surface roughness. Some of these methods are based on roughness measurement devices and equipment in this field. Significant researches are done in surface roughness measuring in steel, copper, plastic, or coated pipes. Methods: In this study, the inner surface roughness of fiberglass pipes, has been evaluated using laboratory methods and roughness measuring devices in several diameters and two different types. Calibration and verification results of the surface roughness tester machine on sandpaper and U-PVC pipe wall surfaces are evaluated. In addition, the effect of roughness parameters and their calculated surface roughness and time using of fiberglass pipe have been investigated. Findings: According to the results, the roughness parameters Rz and Ra in the cut length of 0.8 and 2.5 respectively are suitable parameters to estimate the roughness of the inner surface of the fiberglass tube. Also, the roughness of the inner surface of biaxial tubes is lower than uniaxial tubes. In addition, in comparing the roughness of newly produced and old fiberglass pipes, the surface roughness parameters decrease due to the passage of time and the use in projects. Whereas, the roughness parameters related to the type of pipe have not changed. Conclusion: Based on the results of the Surftest SJ-210 device has best results with accuracy of the roughness height reported for fiberglass pipes is equal to 98.84%. In U-PVC, similar to fiberglass pipe, the average roughness values has been estimated with high accuracy using the Ra with a cutting length of 2.5

Incipient resuspension of silt-clay deposits in oscillatory and unidirectional flows

Incipient motion of cohesive sediment and the role of flow parameters were investigated for separate and combined unidirectional and oscillatory flows. Sediment from Sturgeon Lake, mainly silt and clay with organic matter, was used as bed material In recirculating and wave flumes. Bench-type experiments indicated that when the submerged sediment was under no active hydraulic disturbances, it consolidated substantially. The removal of fine sediment and organic matter from the sediment surface caused greater consolidation of the remaining coarse sediment. The mechanism for incipient motion of cohesive sediment under the action of flowing water was found to be complex. The top surface of the fine-grained sediment exhibited a skin layer which governed the the incipient motion process. Formation of this layer was evidently caused by physicochemical bonding of sediment particles by organic matter and iron in the sediment. When induced shear stress exceeded that required to initiate erosion, the bonded particles started to peel off, leaving pit marks and causing the development of streak lines. Suspension of sediment particles was a part of this process. Incipient motion for unidirectional flow could be expressed in terms of the mean velocity and shear stress necessary to initiate erosion of the cohesive sediment surface. Incipient motion for oscillatory flow could be expressed in terms of maximum orbital velocity and maximum shear stress. The results of the two sets of experiments could be used to speculate on the combined effects of oscillatory and unidirectional flows. It was found for fine cohesive sediment that: (1) the principles governing incipient motion under unidirectional flow are applicable for oscillatory flow; (2) the effects of combined unidirectional and oscillatory flows can be estimated from separate effects of each flow; (3) when induced shear stress exceeds skin bonding strength, peeling off of the skin layer begins; (4) sediment consolidation has little effect on incipient motion; (5) incipient motion of the sediment bed occurs at lower shear stress and velocity under oscillatory flow than under unidirectional flow; (6) a bed with a rough surface is more susceptible than a smooth bed to incipient motion; and (7) bioturbation affects incipient motion of fine-grained sediment

3D Estimation of Metal Elements in Sediments of Caspian Sea with Moving Least Square and Radial Basis Function Interpolation Methods

Spatially continuous data is important in modeling, numerical and computational works. Since sampling points are not continuous, interpolation methods should be used to estimate data at unsampled points. In this paper, radial basis function (RBF) and Moving least square (MLS) interpolation methods are applied to estimate concentration of Nickel, Mercury, Lead, Copper, and Chromium in the Caspian Sea by programming. Cross validation results are also obtained by RBF and MLS methods and have been compared for Lindane, Total DDT, Total HCH, Total Hydrocarbons and Total PAH elements. Input data for MLS and RBF are longitudinal, latitude and depth (3D interpolation) at any point. Output of MLS and RBF is concentration of an element at any point. A new method is introduced for defining constant parameter in RBF. The number of sampling points for calibration and verification tests is analyzed with the values of root mean square error (RMSE) in pollutant parameters. Optimum selection of MLS parameters are used in this paper. The results of concentrations estimation of metal elements in sediments of Caspian Sea by MLS and RBF show that RBF method yields more accurate results than MLS method

Optimization of Solid Waste Collection and Transportation System by Use of the TransCAD: A Case Study

Background & Aims of the Study:  Collection and transportation of municipal solid waste (MSW) for various reasons, especially economic and social are considered as one of the most important elements of the solid waste management system. More than sixty percent of the costs in solid waste management systems in different countries are due to the collection and transportation process including laboring cost, the high price of fuel and machinery and equipments maintenance. This paper aims optimization of solid waste collection routes of Marvdasht, located in Fars province of Iran. Materials & Methods:  This approach consists of several steps. First step includes filed visits, surveys, and interviews with relevant authorities and individuals in the form of questionnaires through which available information about the current route of solid waste are collected. TransCAD, a professional and specialized software for solid waste routing, is then employed for solid waste collection optimization taking into account factors such as shortest path length and time, minimum U-turn and capacity of machinery, etc… Results: The proposed routes were compared to the existing routes for collection of waste considering costs and collection time. According to the results obtained from TransCAD software for the considered case, compared to the current service the total distance and travel time can be decreased up to 16% and 30%, respectively. Conclusions: TransCAD software can perform appropriate routing for solid waste collection, which has the optimized total distance travelled and travel time as did for Marvdasht city

Lattice Boltzmann solution of advection-dominated mass transport problem:a comparison

Abstract This article addresses the abilities and limitations of the Lattice Boltzmann (LB) method in solving advection-dominated mass transport problems. Several schemes of the LB method, including D2Q4, D2Q5, and D2Q9, were assessed in the simulation of two-dimensional advection-dispersion equations. The concept of Single Relaxation Time (SRT) and Multiple Relaxation Time (MRT) in addition to linear and quadratic Equilibrium Distribution Functions (EDF) were taken into account. The results of LB models were compared to the well-known Finite Difference (FD) solutions, including Explicit Finite Difference (EFD) and Crank-Nicolson (CN) methods. All LB models are more accurate than the aforementioned FD schemes. The results also indicate the high potency of D2Q5 SRT and D2Q9 SRT in describing advection-controlled mass transfer problems. The numerical artificial oscillations are observed when the Grid Peclet Number (GPN) is greater than 10, 25, 20, 25, and 10 regarding D2Q4 SRT, D2Q5 SRT, D2Q5 MRT, D2Q9 SRT and D2Q9 MRT, respectively, while the corresponding GPN values obtained for the EFD and CN methods were 2 and 5, respectively. Finally, a coupled system of groundwater and solute transport equations were solved satisfactorily using several LB models. Considering computational time, all LB models are much faster than CN method

Hydrologic Study for South Slough Estuarine Sanctuary, Coos Bay, Oregon submitted to the Scientific/Technical Advisory Group of South Slough Estuarine Sanctuary Management Commission

No hydrologic study has previously been made of the South Slough Estuary drainage basin. Yet, since freshwater runoff is paramount to an estuary, it would seem that such a study is vital to the proper understanding -- and hence management -- of the estuary. Therefore, a brief hydrologic analysis of the South Slough basin has been conducted as part of a class project at Oregon State University. The results are presented on the following pages. This analysis consists of two major parts: (1) The freshwater streamflow that enters the estuary from the drainage basin; and (2) the mixing of that fresh I'/ater within the estuary. It should be noted that hydrologic data for the South Slough basin are made conspicuous by their absence. For this reason, data from nearby collection stations outside the basin have been used in the analyses made for South Slough. This has permitted an estimate of precipitation and runoff. But the results presented here can in no way take the place of the analysis of data collected in the drainage basin itself. Nor should these results, based on monthly averages of precipitation, be compared indiscriminately with measured daily values.This report was a class project for Civil Engineering 529 - Applied Hydrology taught by Professor Peter C. Klingeman.Keywords: Hydrology, Coos Bay, Oregon, South Slough Estuarine Sanctuar

Daily Discharge Forecasting Using Least Square Support Vector Regression and Regression Tree

Prediction of river flow is one of the main issues in the field of water resources management. Because of the complexity of the rainfall-runoff process, data-driven methods have gained increased importance. In the current study, two newly developed models called Least Square Support Vector Regression (LSSVR) and Regression Tree (RT) are used. The LSSVR model is based on the constrained optimization method and applies structural risk minimization in order to yield a general optimized result. Also in the RT, data movement is based on laws discovered in the tree. Both models have been applied to the data in the Kashkan watershed. Variables include (a) recorded precipitation values in the Kashkan watershed stations, and (b) outlet discharge values of one and two previous days. Present discharge is considered as output of the two models. Following that, a sensitivity analysis has been carried out on the input features and less important features has been diminished so that both models have provided better prediction on the data. The final results of both models have been compared. It was found that the LSSVR model has better performance. Finally, the results present these models as a suitable models in river flow forecasting

Process-Constrained Statistical Modeling of Sediment Yield

Sediment transport is a major contributor to a non-point source of pollution impacted by various factors that are modulated by climatic changes and anthropogenic influences. Quantifying and disentangling the contribution of these factors to sediment yield at large scales and across different flow regimes has not been fully explored. Here we present a framework to fine-tune a stochastic sediment yield model by classifying discharge and Suspended Sediment Load (SSL) observations based on the underlying governing processes in unregulated streams with various hydrological regimes. This stochastic model, rooted in copula theory, constructs a joint distribution between discharge and SSL storm events using historical time series of observations, classified based on seasonality, hysteresis patterns, and hydrograph components of the sediment transport processes. We include hydrological, land use, and geological properties of the watersheds to describe and discuss the effects of different factors on applying the underlying dynamics to enhance sediment yield estimation/prediction accuracy. We evaluated the proposed method on 67 streams across the United States. Our results show significant improvements in sediment yield modeling performance