scholarly journals Intertwining Observations and Predictions in Vadose Zone Hydrology: A Review of Selected Studies

Water ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 1107
Author(s):  
Nunzio Romano

Observing state variables, fluxes, and key properties in terrestrial ecosystems should not be seen as disjointed, but rather as fruitfully complementary to ecosystem dynamics modeling. This intertwined view should also take the organization of the monitoring equipment into due account. This review paper explores the value of the interplay between observations and predictions by presenting and discussing some selected studies dealing with vadose zone hydrology. I argue for an advanced vision in carrying out these two tasks to tackle the issues of ecosystem services and general environmental challenges more effectively. There is a recognized need to set up networks of critical zone observatories in which strategies are developed and tested that combine different measurement techniques with the use of models of different complexity.

Author(s):  
Stefan Schmid ◽  
Rudi Kulenovic ◽  
Eckart Laurien

For the validation of empirical models to calculate leakage flow rates in through-wall cracks of piping, reliable experimental data are essential. In this context, the Leakage Flow (LF) test rig was built up at the IKE for measurements of leakage flow rates with reduced pressure (maximum 1 MPA) and temperature (maximum 170 °C) compared to real plant conditions. The design of the test rig enables experimental investigations of through-wall cracks with different geometries and orientations by means of circular blank sheets with integrated cracks which are installed in the tubular test section of the test rig. In the paper, the experimental LF set-up and used measurement techniques are explained in detail. Furthermore, first leakage flow measurement results for one through-wall crack geometry and different imposed fluid pressures at ambient temperature conditions are presented and discussed. As an additional aspect the experimental data are used for the determination of the flow resistance of the investigated leak channel. Finally, the experimental results are compared with numerical results of WinLeck calculations to prove specifically in WinLeck implemented numerical models.


Author(s):  
Pierre-Yves Wuillaume ◽  
Pierre Ferrant ◽  
Aurélien Babarit ◽  
François Rongère ◽  
Mattias Lynch ◽  
...  

This paper presents validation tests for a new numerical tool for the numerical simulation of marine operations. It involves multibody dynamics modeling, wave-structure interactions with large amplitude body motion and cable’s dynamic modeling. Hydrodynamic loads are computed using the WS_CN weakly nonlinear potential flow solver, based on the weak-scatterer hypothesis. Large deformation of the wetted body surfaces can be taken into account. Firstly the ECN’s WS_CN solver capabilities are extended to multibody simulations. A first validation test is performed by comparing numerical results to the experimental data of [1]. Then, a second validation test is proposed. It consists in the ballasting operation of a spar. The experimental set-up is described.


Author(s):  
Chandramoulee Krishnamoorthy ◽  
Rahul P. Rao ◽  
Afshin J. Ghajar

This review paper specifically concentrates on heat transfer in micro-tubes and eleven experiments (on liquid flow) and two experiments (on gaseous flow) from 1991 to 2007 are reviewed critically with respect to measurement techniques, instrumentation; and factors like surface roughness and diameter that may play an important role at these small scales. Moreover, a comprehensive list of numerical and analytical results (for both liquid and gaseous flows) is presented in this paper. Interestingly, the effect of surface roughness on heat transfer does not seem to have been investigated thoroughly, as it has been observed to play a key role in influencing heat transfer at small diameters. The state-of-art review thus provides the contemporary experimenters in the field of mini-micro channel heat transfer, this tabulated data that can be used to understand how the different parameters affect the heat transfer in these small scales and a data-bank to validate future numerical and experimental work. The present study identifies the various factors that have contributed in the disparity of results found in the literature and finds that there is a need to investigate certain issues like the effects of roughness, diameter, and secondary flow due to buoyancy on heat transfer and transition. Moreover, it was observed that the start and end of the transition region at these small diameters are not validated by the any of the existing macro-scale correlations.


Author(s):  
Lucie Depeigne ◽  
Emilija Zdraveva

One of the largest fields of application of electrospun materials is the biomedical field, including development of scaffolds for tissue engineering, drug delivery and wound healing. Electrospinning appears as a promising technique in terms of scaffolds composition and architecture, which is the main aspect of this review paper, with a special attention to natural polymers including collagen, fibrinogen, silk fibroin, chitosan, chitin etc. Thanks to the adaptability of the electrospinning process, versatile hybrid, custom tailored structure scaffolds have been reported. The same is achieved due to the vast biomaterials’ processability as well as modifications of the basic electrospinning set-up and its combination with other techniques, simultaneously or by post-processing.


2019 ◽  
Author(s):  
Tea Thum ◽  
Silvia Caldararu ◽  
Jan Engel ◽  
Melanie Kern ◽  
Marleen Pallandt ◽  
...  

Abstract. The dynamics of terrestrial ecosystems are shaped by the coupled cycles of carbon, nitrogen and phosphorus, and strongly depend on the availability of water and energy. These interactions shape future terrestrial biosphere responses to global change. Many process-based models of the terrestrial biosphere have been gradually extended from considering carbon-water interactions to also including nitrogen, and later, phosphorus dynamics. This evolutionary model development has hindered full integration of these biogeochemical cycles and the feedbacks amongst them. Here we present a new terrestrial ecosystem model QUINCY (QUantifying Interactions between terrestrial Nutrient CYcles and the climate system), which is formulated around a consistent representation of element cycling in terrestrial ecosystems. This new model includes i) a representation of plant growth which separates source (e.g. photosynthesis) and sink (growth rate of individual tissues, constrained by nutrients, temperature, and water availability) processes; ii) the acclimation of many ecophysiological processes to meteorological conditions and/or nutrient availabilities; iii) an explicit representation of vertical soil processes to separate litter and soil organic matter dynamics; iv) a range of new diagnostics (leaf chlorophyll content; 13C, 14C, and 15N isotope tracers) to allow for a more in-depth model evaluation. We present the model structure and provide an assessment of its performance against a range of observations from global-scale ecosystem monitoring networks. We demonstrate that the framework is capable of consistently simulating ecosystem dynamics across a large gradient in climate and soil conditions, as well as across different plant functional types. To aid this understanding we provide an assessment of the model's sensitivity to its parameterisation and the associated uncertainty.


2013 ◽  
Vol 12 (3) ◽  
pp. vzj2013.07.0128 ◽  
Author(s):  
Binayak P. Mohanty ◽  
Michael Cosh ◽  
Venkat Lakshmi ◽  
Carsten Montzka

2005 ◽  
Vol 295-296 ◽  
pp. 423-430 ◽  
Author(s):  
Ji Gui Zhu ◽  
S.H. Ye ◽  
Xue You Yang ◽  
Xing Hua Qu ◽  
C.J. Liu ◽  
...  

Rapid progress in modern manufacturing demands for better measurement technique with on-line characteristics. This paper presents a systematic visual solution for on-line industrial 3D measurement. The solution comprises two parts, a multi-sensor visual inspecting station (MSVIS) and a digital close-range visual inspecting station (DCVIS). MSVIS is an integrated system with many sensors. It can meet the requirement of application with sparse measuring points distributed within a large volume. DCVIS only contains two digital cameras with one or more projectors. It has high relative accuracy and a small set up volume and is suitable for applications with dense measuring points. The combined use of MSVIS and DCVIS can provide a general solution for on-line industrial 3D measurement.


2010 ◽  
Vol 39 (5) ◽  
pp. 1570-1584 ◽  
Author(s):  
D. Kaplan ◽  
R. Muñoz-Carpena ◽  
Y. Wan ◽  
M. Hedgepeth ◽  
F. Zheng ◽  
...  

2015 ◽  
Vol 4 (1) ◽  
pp. 125 ◽  
Author(s):  
Wilma Polini ◽  
Giovanni Moroni

Coordinate Measuring Machine (CMM) inspection planning is an activity performed by well-trained operators, but different measurement techniques, using the same data analysis algorithms yield in different measurement results. This is a well-recognized source of uncertainty in coordinate measurement. A CMM, provided with an automatic inspection planning (CAIP) system, permits to implement more accurate and efficient operating procedures and to fit higher quality assurance standards and tighter production timings.In this paper we present a frame of a CAIP system, able to deal with almost all the decisional stages of CMM inspection. Moreover, original approaches have been developed and presented in inspection feature selection, part set-up, probe configuration, and path planning.


2005 ◽  
Vol 58 (3) ◽  
pp. 257-265 ◽  
Author(s):  
José Carlos de Araújo ◽  
Donald W. Knight

The present review paper has the objective of presenting and briefly discussing the state-of-the-art papers on sediment yield (SY) measurement. About 80 publications are referred to, representing all continents, and more than 30 countries. It is observed that SY measurement technique is a much stronger function of temporal than of spatial resolution. Annual average SY data of 364 catchments are summarized. Global data presents no trend concerning catchment area and the same behavior is observed for the continents, except for Africa, which presents a consistent decrease of SY with increasing area. A graphical representation of the spatial and temporal applicability of the different SY measurement techniques is shown.


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