Controlled clearance piston gauges are used as primary pressure standards at many national metrology institutes. The National Institute of Standards and Technology, in collaboration with the National Physical Laboratory (India), is studying the performance of a new generation of controlled clearance gauges that offer the potential for reduced uncertainties. The gauges are also well suited to in...

Evaluating the sustainability of water uses in shallow aquifers is fundamental for both environmental and socio-economic reasons. Groundwater models are the main tools to sustain informed management plans, yet simulation results are affected by both epistemic and parametric uncertainties. In this study, we aim at investigating the effect of model uncertainties on three assessment criteria: dept...

Wetland ecosystems provide multiple functions and services for the well-being of humans. In urban environments, planning and decision making about wetland restoration inevitably involves conflicting objectives, trade-offs, uncertainties and conflicting value judgments. This study applied trade-off and multi criteria decision analysis to analyze and quantify the explicit trade-offs between the s...

[1] Hydraulic tomography is a cost-effective technique for characterizing the heterogeneity of hydraulic parameters in the subsurface. During hydraulic tomography surveys a large number of hydraulic heads (i.e., aquifer responses) are collected from a series of pumping or injection tests in an aquifer. These responses are then used to interpret the spatial distribution of hydraulic parameters o...

Hydraulic actuators play an important role in various industries. In the last decades, to improve system performance, some advanced control methods have been developed. Backstepping control, which can deal with nonlinearities, is widely used hydraulic motion control. This paper focuses on high-frequency position servo of systems proportional valves. backstepping controllers, valve dynamics are ...

INTRODUCTION: The calculation of Manning n values has been of interest since the Manning equation was presented in the late 1800s (Henderson, 1966). While estimation of n vahm for normal channels has been fairly well standardized, the estimation of n values in areas of dense vegetation continues to be subject to large variations depending on the experience of the engineer and the perceived dens...

Thermal-hydraulic (T-H) passive systems play a crucial role in the development of future solutions for nuclear power plant technologies. A fundamental issue still to be resolved is the quantification of the reliability of such systems. The difficulty comes from the uncertainties in the evaluation of their performance, because of the lack of experimental and operational data and of validated mod...

A review of uncertainty quantification techniques is provided for a variety situations involving uncertainties in model inputs (independent variables). The interest are divided into three categories: (i) when prediction quantified based on uncertain inputs, (ii) parameter estimate calculated by propagation from measured and outputs, (iii) corresponding estimates. For all situations, linearizati...