Comparison of new and conventional field methods for characterizing trichloroethene distribution in a fractured sandstone

2020 ◽  
pp. 27-28
Author(s):  
S.N. Sterling ◽  
B.L. Parker ◽  
J.A. Cherry
2006 ◽  
Vol 32 (5) ◽  
pp. 355-366 ◽  
Author(s):  
Hans-Erik Andersen ◽  
Stephen E Reutebuch ◽  
Robert J McGaughey

2020 ◽  
Author(s):  
Matthew Holden ◽  
Richard Brazier ◽  
Brett Day ◽  
Sam Bridgewater ◽  
Yog Watkins

<p>It is widely recognised that the intensification of agriculture has had significant impacts on soil condition and function, negatively affecting soil structure, fertility and biological diversity<strong>. </strong>Such impacts have contributed to reduced soil carbon storage, hydrological function, the storage of nutrients, the filtration of pollutants and potential crop productivity. It is therefore important that agricultural systems adapt to ensure the provision of food alongside multiple other critical ecosystem services (ES). Developing our understanding of how to quantify soil function in a given state is important in calculating the value of soil ES and natural capital (NC) under different management scenarios. It is critical for both the establishment of cost effective agri-environment policies and in driving sustainable on-farm decision making at management appropriate scales. </p><p>This study aims to examine how field methods, used for the assessment of soil condition and function, can be applied to determine (i) How baseline soil condition measurements relate to soil function across organic and conventional field sites and (ii) Whether enhanced soil function is observed in agricultural soils under organic agriculture and if so, whether the potential economic benefits could offset the loss in crop productivity.</p><p>The study was conducted at Clinton Devon Estate in South West England. Nine conventional and nine organic fields, reflecting the main rotational land uses on the estate, were selected. Baseline soil samples were collected from each field in winter 2018 for the analysis of; total carbon (TC), total nitrogen, plant available phosphorus, soil texture, pH and bulk density (BD). Land management data was collected from the farmers for each field. Four soil functions/services were selected for monitoring; nutrient filtering and retention, soil organic matter decomposition, carbon storage and crop production. Crop yields for maize, cereals and grass silage were collected from each of the soil sampled points immediately ahead of harvest in 2019. BD and TC from each sample were used to estimate carbon storage.  Three sites from each field were selected for the assessment of soil organic matter decomposition using the standardised and globally applied Tea Bag Index method (Keuskamp et al., 2013). A smaller sub-set of six fields (three organic and three conventional) were selected for the determination of nutrient filtering and retention. Porous pots, ten replicates per field site, were installed below crop rooting depths in October 2018 for monitoring through the 2018 – 2019 and 2019 – 2020 drainage seasons. A sample of soil pore water was extracted (fortnightly) and analysed for nitrate, nitrite, ammonia and phosphate, allowing a comparison of nutrient leaching between sites. </p><p>The data from this study will be presented for the assessment of whether quantification of soil functions at the field scale can help in the identification of useful baseline indicators and contribute to the valuation of soil ES and NC. </p><p> </p><p> </p><p><strong>References: </strong></p><p>Keuskamp, J.A., Dingemans, B.J.J., Lehtinen, T., Sarneel, J.M. and Hefting, M.M. (2013), Tea Bag Index: a novel approach to collect uniform decomposition data across ecosystems. Methods Ecol Evol, 4: 1070-1075. doi:10.1111/2041-210X.12097</p>


2013 ◽  
Vol 8 (No. 1) ◽  
pp. 13-25 ◽  
Author(s):  
J. Balkovič ◽  
Z. Rašeková ◽  
V. Hutár ◽  
J. Sobocká ◽  
R. Skalský

We tested the performance of a formalized digital soil mapping (DSM) approach comprising fuzzy k-means (FKM) classification and regression-kriging to produce soil type maps from a fine-scale soil observation network in Ri&scaron;ňovce, Slovakia. We examine whether the soil profile descriptions collected merely by field methods fit into the statistical DSM tools and if they provide pedologically meaningful results for an erosion-affected area. Soil texture, colour, carbonates, stoniness and genetic qualifiers were estimated for a total of 111 soil profiles using conventional field methods. The data were digitized along semi-quantitative scales in 10-cm depth intervals to express the relative differences, and afterwards classified by the FKM method into four classes A&ndash;D: (i) Luvic Phaeozems (Anthric), (ii)&nbsp;Haplic Phaeozems (Anthric, Calcaric, Pachic), (iii) Calcic Cutanic Luvisols, and (iv) Haplic Regosols (Calcaric). To parameterize regression-kriging, membership values (MVs) to the above A&ndash;D class centroids were regressed against PCA-transformed terrain variables using the multiple linear regression method (MLR). MLR yielded significant relationships with R<sup>2</sup> ranging from 23% to 47% (P &lt; 0.001) for classes A, B and D, but only marginally significant for Luvisols of class C (R<sup>2</sup> = 14%, P &lt; 0.05). Given the results, Luvisols were then mapped by ordinary kriging and the rest by regression-kriging. A &ldquo;leave-one-out&rdquo; cross-validation was calculated for the output maps yielding R<sup>2</sup> of 33%, 56%, 22% and 42% for Luvic Phaeozems, Haplic Phaeozems, Luvisols and also Regosols, respectively (all P &lt; 0.001). Additionally, the pixel-mixture visualization technique was used to draw a synthetic digital soil map. We conclude that the DSM model represents a fully formalized alternative to classical soil mapping at very fine scales, even when soil profile descriptions were collected merely by field estimation methods. Additionally to conventional soil maps it allows to address the diffuse character in soil cover, both in taxonomic and geographical interpretations.


Author(s):  
E. Betzig ◽  
A. Harootunian ◽  
M. Isaacson ◽  
A. Lewis

In general, conventional methods of optical imaging are limited in spatial resolution by either the wavelength of the radiation used or by the aberrations of the optical elements. This is true whether one uses a scanning probe or a fixed beam method. The reason for the wavelength limit of resolution is due to the far field methods of producing or detecting the radiation. If one resorts to restricting our probes to the near field optical region, then the possibility exists of obtaining spatial resolutions more than an order of magnitude smaller than the optical wavelength of the radiation used. In this paper, we will describe the principles underlying such "near field" imaging and present some preliminary results from a near field scanning optical microscope (NS0M) that uses visible radiation and is capable of resolutions comparable to an SEM. The advantage of such a technique is the possibility of completely nondestructive imaging in air at spatial resolutions of about 50nm.


ANRI ◽  
2020 ◽  
pp. 31-44
Author(s):  
Aleksey Ekidin ◽  
Aleksey Vasil'ev ◽  
Maksim Vasyanovich ◽  
Evgeniy Nazarov ◽  
Mariya Pyshkina ◽  
...  

The article presents the results of field studies in the area of the Belarusian NPP in the pre-operational period. The «background» contents of gamma-emitting radionuclides in individual components of the environment are determined. The main array of dose rate measurements in the area of the NPP construction site is in the range 0.048 ÷ 0.089 μSv/h. External radiation in the surveyed area is formed at 96% due to 40K, 226Ra and 232Th. The information obtained can be used to correctly interpret the data of future radiation monitoring during normal operation of nuclear power plants.


Journal ◽  
2016 ◽  
Vol 6 ◽  
Author(s):  
Melanie A. Medeiros ◽  
Jennifer Guzmán

Trends in higher education pedagogy increasingly point to the importance of transformational experiences as the capstone of liberal arts education. Practitioners of ethnography, the quintessential transformational experience of the social sciences, are well-positioned to take the lead in designing courses and term projects that afford undergraduate students opportunities to fundamentally reshape their understanding of the social world and their own involvement within it. Furthermore, in the United States, colleges and universities have become proponents of service learning as a critical component of a holistic educational experience. In this article, we describe how service learning can be incorporated into training students in ethnographic field methods as a means to transformational learning and to give them skills they can use beyond the classroom in a longer trajectory of civic participation. We discuss strategies, opportunities, and challenges associated with incorporating service learning into courses and programs training students in ethnographic field methods and propose five key components for successful ethnographic service learning projects. We share student insights about the transformational value of their experiences as well as introduce some ethical concerns that arise in ethnographic service-learning projects.


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