The influence of memory, sample size effects, and filter paper material on online laser-based plant and soil water isotope measurements

2017 ◽  
Vol 31 (6) ◽  
pp. 509-522 ◽  
Author(s):  
Jiangpeng Cui ◽  
Lide Tian ◽  
Cynthia Gerlein-Safdi ◽  
Dongmei Qu
1989 ◽  
Vol 38 (1-2) ◽  
pp. 65-69 ◽  
Author(s):  
Yoko Imaizumi

AbstractNation-wide data in Japan on births and prenatal deaths of 16 sets of quintuplets during 1974-1985 were analysed. Among the 16 sets, 3 sets were liveborn, 8 were stillborn, and 5 were mixed, with a stillbirth rate of 0.64 (51/80). Effects of sex, maternal age and birth order on the stillbirth rate were not considered because of the small sample size. Effects of gestational age and birthweight on stillbirth rate were also examined. The mean weight of the 40 quintuplet individuals was 1,048 g.


2021 ◽  
Author(s):  
Aina Johannessen ◽  
Alena Dekhtyareva ◽  
Andrew Seidl ◽  
Harald Sodemann

<p>Transport of water from an evaporation source towards a precipitation sink is the essence of the atmospheric water cycle. However, there are significant challenges with the representation of the atmospheric water cycle in models. For example, incomplete representation of sub-grid scale processes like evaporation, mixing or precipitation can lead to substantial model errors. Here we investigate the combined use of Lagrangian and Eulerian models and in-situ observations of stable water isotopes to reduce such sources of model error. The atmospheric water cycle in the Nordic Seas during cold air outbreaks (CAOs) is confined to a limited area, and thus may be used as a natural laboratory for hydrometeorological studies. We apply Lagrangian and Eulerian models together with observations taken during the ISLAS2020 field campaign in the Arctic in spring 2020 for characterising source-sink relationships in the water cycle. During the field campaign, we observed an alternating sequence of cold air outbreaks (CAO) and warm air intrusions (WAI) over the key measurement sites of Svalbard and northern Norway. Thereby, meteorological and stable water isotope measurements have been performed at multiple sites both upstream and downstream of the CAOs and WAIs. The Lagrangian model FLEXPART has been run with the input data from the regional convection-permitting numerical weather prediction model AROME Arctic at 2.5 km resolution to investigate transport patterns. The combination of observations and model simulations allows us to quantify the connection between source and sink for different weather systems, as well as the link between large-scale transport and stable water isotopes. Findings will lead to a better understanding of processes in the water cycle and the degree of conservation of isotopic signals during transport. This study may also serve as a guideline on how to evaluate the performance of Lagrangian transport models using stable water isotope measurements, and on how to detect constraints for quantifying the transport route and evaporation source from stable water isotope measurements for future work, including an aircraft campaign planned in 2021.</p>


1987 ◽  
Vol 22 (3) ◽  
pp. 123-127 ◽  
Author(s):  
P.V. Kirch ◽  
M.S. Allen ◽  
V.L. Butler ◽  
T.L. Hunt

2014 ◽  
Vol 621 ◽  
pp. 158-164
Author(s):  
Hao Yan Wang ◽  
Zhe He Yao ◽  
De Qing Mei

Micro/meso forming, as an emerging manufacturing process for miniature metallic workpieces, has attracted great attention since the 1990s due to its high production efficiency, low material waste and high precision. Due to the so-called size effects in the scaling down, many traditional theories in metal forming cannot be simply applied to the micro/meso forming. In this study, the micro/meso upsetting experiments of Brass H62 were conducted at various temperatures. The stress−strain curves in the experiments were measured and compared. The effects of the temperature and the sample size on the flow stress were discussed. It is found that the flow stress of the material decreased with the decrease of the sample size at room temperature. However, the flow stress of the material may increase with the decrease of the sample size at elevated temperatures. The results indicate that the size effects in the micro/meso forming are significantly affected by the processing temperature.


2010 ◽  
Vol 127 (3) ◽  
pp. 2001-2001
Author(s):  
Eric Brandao ◽  
Erico Fulco ◽  
Arcanjo Lenzi ◽  
Emiel Tijs

2016 ◽  
Vol 13 (10) ◽  
pp. 3175-3186 ◽  
Author(s):  
Guo Chen ◽  
Karl Auerswald ◽  
Hans Schnyder

Abstract. Hydrophilic surfaces influence the structure of water close to them and may thus affect the isotope composition of water. Such an effect should be relevant and detectable for materials with large surface areas and low water contents. The relationship between the volumetric solid : water ratio and the isotopic fractionation between adsorbed water and unconfined water was investigated for the materials silage, hay, organic soil (litter), filter paper, cotton, casein and flour. Each of these materials was equilibrated via the gas phase with unconfined water of known isotopic composition to quantify the isotopic difference between adsorbed water and unconfined water. Across all materials, isotopic fractionation was significant (p<0.05) and negative (on average −0.91 ± 0.22 ‰ for 18∕16O and −20.6 ± 2.4 ‰ for 2∕1H at an average solid : water ratio of 0.9). The observed isotopic fractionation was not caused by solutes, volatiles or old water because the fractionation did not disappear for washed or oven-dried silage, the isotopic fractionation was also found in filter paper and cotton, and the fractionation was independent of the isotopic composition of the unconfined water. Isotopic fractionation became linearly more negative with increasing volumetric solid : water ratio and even exceeded −4 ‰ for 18∕16O and −44 ‰ for 2∕1H. This fractionation behaviour could be modelled by assuming two water layers: a thin layer that is in direct contact and influenced by the surface of the solid and a second layer of varying thickness depending on the total moisture content that is in equilibrium with the surrounding vapour. When we applied the model to soil water under grassland, the soil water extracted from 7 and 20 cm depth was significantly closer to local meteoric water than without correction for the surface effect. This study has major implications for the interpretation of the isotopic composition of water extracted from organic matter, especially when the volumetric solid : water ratio is larger than 0.5 or for processes occurring at the solid–water interface.


2007 ◽  
Vol 99 (21) ◽  
Author(s):  
J. C. González ◽  
M. Muñoz ◽  
N. García ◽  
J. Barzola-Quiquia ◽  
D. Spoddig ◽  
...  
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