scholarly journals Capillary rise quantifications based on in-situ artificial deuterium peak displacement and laboratory soil characterization

2011 ◽  
Vol 15 (5) ◽  
pp. 1629-1639 ◽  
Author(s):  
O. Grünberger ◽  
J. L. Michelot ◽  
L. Bouchaou ◽  
P. Macaigne ◽  
Y. Hsissou ◽  
...  

Abstract. In arid environments, water rises from the saturated level of a shallow aquifer to the drying soil surface where evaporation occurs. This process plays important roles in terms of plant survival, salt balance and aquifer budget. A new field quantification method of this capillary rise flow is proposed using micro-injections (6 μL) of a deuterium-enriched solution (δ value of 63 000‰ vs. V-SMOW) into unsaturated soil at a 1 m depth. Evaluation of peak displacement from profile sampling 35 days later delivered an estimate that was compared with outputs of numerical simulation based on laboratory hydrodynamic measurements assuming a steady state regime. A rate of 3.7 cm y−1 was estimated at a Moroccan site, where the aquifer water depth was 2.44 m. This value was higher than that computed from the relationship between evaporation rates and water level depth based on natural isotopic profile estimates, but it was lower than every estimate established using integration of the van Genuchten closed-form functions for soil hydraulic conductivity and retention curve.

2010 ◽  
Vol 7 (5) ◽  
pp. 7757-7778 ◽  
Author(s):  
O. Grünberger ◽  
J. L. Michelot ◽  
L. Bouchaou ◽  
P. Macaigne ◽  
Y. Hsissou ◽  
...  

Abstract. In arid contexts, water rises from the saturated level of a shallow aquifer to the drying soil surface where evaporation takes place. This process plays important roles in terms of plant survival, salt balance and aquifer budget. A new field quantification method of this capillary rise flow is proposed using micro-injections (6 μL) of deuterium-enriched solution (δ value of 63 000‰ vs. V-SMOW) into unsatured soil at 1 m depth. Evaluation of peak displacement from a profile sampling 35 days later, delivered estimates that were compared with outputs of numerical simulation based on laboratory hydrodynamic measurements. A rate of 3.7 cm y−1 was observed in a Moroccan site where the aquifer level was 2.44 m deep. This value was higher, than other estimates based on natural diffusion with the same depth of aquifer, but lower than the estimates established using integration of van Genutchen closed-form functions for soil hydraulic conductivity and retention curve.


Author(s):  
O.L. Krivanek ◽  
G.J. Wood

Electron microscopy at 0.2nm point-to-point resolution, 10-10 torr specimei region vacuum and facilities for in-situ specimen cleaning presents intere; ing possibilities for surface structure determination. Three methods for examining the surfaces are available: reflection (REM), transmission (TEM) and profile imaging. Profile imaging is particularly useful because it giv good resolution perpendicular as well as parallel to the surface, and can therefore be used to determine the relationship between the surface and the bulk structure.


Author(s):  
Kun Lee ◽  
Jingyi Si ◽  
Ricai Han ◽  
Wei Zhang ◽  
Bingbing Tan ◽  
...  

There are more supports for the view that human papillomavirus (HPV) infection might be an etiological factor in the development of cervical cancer when the association of persistent condylomata is considered. Biopsies from 318 cases with squamous cell carcinoma of uterine cervix, 48 with cervical and vulvar condylomata, 14 with cervical intraepithelial neoplasia (CIN), 34 with chronic cervicitis and 24 normal cervical epithelium were collected from 5 geographic regions of China with different cervical cancer mortalities. All specimens were prepared for Dot blot, Southern blot and in situ DNA-DNA hybridizations by using HPV-11, 16, 18 DNA labelled with 32P and 3H as probes to detect viral homologous sequences in samples. Among them, 32 cases with cervical cancer, 27 with condyloma and 10 normal cervical epitheliums were randomly chosen for comparative EM observation. The results showed that: 1), 192 out of 318 (60.4%) cases of cervical cancer were positive for HPV-16 DNA probe (Table I)


Author(s):  
Shotaro Tada ◽  
Norifumi Asakuma ◽  
Shiori Ando ◽  
Toru Asaka ◽  
Yusuke Daiko ◽  
...  

This paper reports on the relationship between the H2 chemisorption properties and reversible structural reorientation of the possible active site around Al formed in-situ within polymer-derived ceramics (PDCs) based on...


Agronomy ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 938
Author(s):  
Ladislav Menšík ◽  
Lukáš Hlisnikovský ◽  
Pavel Nerušil ◽  
Eva Kunzová

The aim of the study was to compare the concentrations of risk elements (As, Cu, Mn, Ni, Pb, Zn) in alluvial soil, which were measured by a portable X-ray fluorescence analyser (pXRF) in situ (FIELD) and in the laboratory (LABORATORY). Subsequently, regression equations were developed for individual elements through the method of construction of the regression model, which compare the results of pXRF with classical laboratory analysis (ICP-OES). The accuracy of the measurement, expressed by the coefficient of determination (R2), was as follows in the case of FIELD–ICP-OES: Pb (0.96), Zn (0.92), As (0.72), Mn (0.63), Cu (0.31) and Ni (0.01). In the case of LABORATORY–ICP-OES, the coefficients had values: Pb (0.99), Zn (0.98), Cu and Mn (0.89), As (0.88), Ni (0.81). A higher dependence of the relationship was recorded between LABORATORY–ICP-OES than between FIELD–ICP-OES. An excellent relationship was recorded for the elements Pb and Zn, both for FIELD and LABORATORY (R2 higher than 0.90). The elements Cu, Mn and As have a worse tightness in the relationship; however, the results of the model have shown its applicability for common use, e.g., in agricultural practice or in monitoring the quality of the environment. Based on our results, we can say that pXRF instruments can provide highly accurate results for the concentration of risk elements in the soil in real time for some elements and meet the principle of precision agriculture: an efficient, accurate and fast method of analysis.


2021 ◽  
Vol 111 (03) ◽  
pp. 118-123
Author(s):  
Andreas Zabel ◽  
Simon Strodick ◽  
Robert Schmidt ◽  
Frank Walther ◽  
Dirk Biermann ◽  
...  

Der Beitrag befasst sich mit Teilaspekten bei der Entwicklung von Methoden zur gezielten, bearbeitungsparallelen Oberflächenkonditionierung beim Tiefbohren. Konkret handelt es sich um messtechnische und simulationsbasierte Ansätze zur Identifikation von thermomechanischen Prozesszuständen beim BTA- und ELB-Verfahren. Hierbei werden Möglichkeiten zur Gewinnung von Prozessdaten sowohl mit einer in-situ eingesetzten Sensorik als auch mit begleitend durchgeführten FEM-Simulationen betrachtet. Diese Daten bilden die Grundlage einer Prozessregelung für die beiden Tiefbohrverfahren. Im zweiten Teil werden nun die Arbeiten und Ergebnisse zum ELB-Tiefbohren behandelt.   The article deals with aspects of developing methods specifically for surface conditioning in deep hole drilling parallel to machining. This involves metrological and simulation-based approaches for identifying thermo-mechanical process conditions in both BTA and ELB process. Ways for obtaining process data both with sensor technology used in-situ and with FEM simulations performed concomitantly are investigated. These data form the basis of a deep hole process control. The second part presents the work and the results on single lip deep hole drilling.


2001 ◽  
Author(s):  
B. M. Fichera ◽  
R. L. Mahajan ◽  
T. W. Horst

Abstract Accurate air temperature measurements made by surface meteorological stations are demanded by climate research programs for various uses. Heating of the temperature sensor due to inadequate coupling with the environment can lead to significant errors. Therefore, accurate in-situ temperature measurements require shielding the sensor from exposure to direct and reflected solar radiation, while also allowing the sensor to be brought into contact with atmospheric air at the ambient temperature. The difficulty in designing a radiation shield for such a temperature sensor lies in satisfying these two conditions simultaneously. In this paper, we perform a computational fluid dynamics analysis of mechanically aspirated radiation shields (MARS) to study the effect of geometry, wind speed, and interplay of multiple heat transfer processes. Finally, an artificial neural network model is developed to learn the relationship between the temperature error and specified input variables. The model is then used to perform a sensitivity analysis and design optimization.


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