Critical conditions for the wetting of soils

The wettability of soil is of great importance for plants and soil biota and in determining whether flooding and soil erosion will occur. The analysis used in common measurements of soil hydrophobicity makes the assumption that water always enters soils if the average contact angle between the soil and water is 90 degrees or lower; these tests have been used for decades. The authors show theoretically and experimentally that water cannot enter many soils unless the contact angle is considerably lower than this, down to approximately 50 degrees. This difference generates serious errors in determining and modeling soil wetting behavior

Plastron properties of a superhydrophobic surface

Most insects and spiders drown when submerged during flooding or tidal inundation, but some are able to survive and others can remain submerged indefinitely without harm. Many achieve this by natural adaptations to their surface morphology to trap films of air, creating plastrons which fix the water-vapor interface and provide an incompressible oxygen-carbon dioxide exchange surface. Here the authors demonstrate how the surface of an extremely water-repellent foam mimics this mechanism of underwater respiration and allows direct extraction of oxygen from aerated water. The biomimetic principle demonstrated can be applied to a wide variety of man-made superhydrophobic materials

Assessing the Awareness of Lead Hazards in the Greater Burlington Area

Introduction. Lead is a heavy metal found in and around homes built before 1978, comprising more than 80% of the housing stock in Chittenden County, Vermont. Lead exposure during infancy and childhood can have deleterious effects on development. Our study assessed baseline community understanding of potential household lead hazards in Chittenden County, Vermont. Methods.. 123 paper, 10-question surveys were randomly administered to Chittenden County, VT residents to assess recognition of lead toxicology symptoms and awareness of lead safety programs. Scores were treated as continuous variables, demographically grouped, and analyzed using non-parametric statistical analysis (Mann-Whitney & Kruskal-Wallis). Individual questions were treated as dichotomous variables, demographically grouped and analyzed using chi-squared testing. Results.. 48% of survey participants understood the interaction between ADHD and lead or knew the importance of window maintenance. 54.5% were aware of the Burlington Lead Program\u27s assistance program. Participants earning less than $60,000 and those with less than a graduate degree scored statistically lower (p Conclusion.. Lesser-known lead poisoning symptoms and home interventions that decrease lead exposure should be emphasized to the community. High-risk groups requiring targeted education include those who rent, have lower income and education levels. Primary care providers could serve a larger role in educating patients. Additional efforts should be made to publicize services offered by the Burlington Lead Program.https://scholarworks.uvm.edu/comphp_gallery/1241/thumbnail.jp

A social accounting matrix for Iraq

This paper deals with the challenges associated with the generation of a social accounting matrix (SAM) in conditions where up-to-date measured data are particularly scarce and provides future researchers of economic systems with the first SAM for Iraq. It delivers a unique and updated countrywide database for use in modeling and policy analysis and applies this database to the empirical investigation into the expected effects of economic diversification in Iraq as stated in the recent Iraq National Development Plan 2013-2017

Socio-economic studies with social accounting and sociodemographic matrices : an application to Portugal.

In looking for empirical evidence about the activity of countries, a proposal is made for studying (measuring and modelling) the activity of countries through the use of Social Accounting Matrices (SAMs) and Socio-Demographic Matrices (SDMs). SAMs and SDMs are presented as tools that have specific features for conducting studies in several different areas, as well as for supporting policy decision processes. Based on methodological principles that are derived mainly from the works of Richard Stone, emphasis is placed on the desirability of working in a matrix format, which includes not only people (SDM), but also, at the same time, activities, products, factors of production and institutions (SAM). This is considered to be a way of capturing the relevant network of linkages and the corresponding multiplier effects, which can be used for the subsequent modelling of the activity of the countries studied. A method will be proposed for the construction of these matrices. In the case of the SAMs, it is proposed that their design and construction should adopt, at least as their starting point, the latest version of the System of National Accounts (2008 SNA) and the corresponding results of its adoption/adaptation by different countries. The exposition of this proposal is accompanied by an example applied to Portugal.Financial support provided by FCT (Fundação para a Ciência e a Tecnologia)Portugal for the research and writing of this article, which forms part of the Strategic Project for 2011-13 (PEst- OE/EGE/UI0436/2011)

Mineralogical and environmental features of the asturian copper mining district (Spain): A review

Persistence and bioavailability of heavy metals in soils adjacent to ancient Cu mines continues to be a possible threat to human health. However, there have been very few studies to determine this risk. Asturias (Northwest of Spain) is a Cu metallogenic province with abundant epithermal-type deposits, whose paragenetic sequences also include As, Co, Ni, Sb and Hg minerals. Several Cu mines have been worked in this region since prehistoric times and the six most significant ones are studied in this work to provide new insights into the potential for both contemporary and past contamination due to Cu mining to impact human health. The main characteristics of each deposit were defined by means of optical and scanning-electron microscopy, X-ray diffraction and Electron Probe Micro Analysis. These characteristics were used to better interpret the environmental results, obtained from samples of mining wastes, soils and waters, which were analyzed by means of X-ray fluorescence and ICPMS.Many of these mines are almost forgotten, but their negative effects will endure over time, since they were abandoned long before the introduction of environmental regulations to control metal release. An inheritance of derelict mine facilities and spoil heaps still remains in the sites of this district. The spoil heaps are the main pollution sources and concentrations of up to 2.1% Cu and 0.4% As, among others, were found in the surrounding soils. The potential adverse health effects of the exposure to these elements have been assessed, finding significant risks for potential receptors, such as farmers or local residents

Embedded pitch adapters: a high-yield interconnection solution for strip sensors

A proposal to fabricate large area strip sensors with integrated, or embedded, pitch adapters is presented for the End-cap part of the Inner Tracker in the ATLAS experiment. To implement the embedded pitch adapters, a second metal layer is used in the sensor fabrication, for signal routing to the ASICs. Sensors with different embedded pitch adapters have been fabricated in order to optimize the design and technology. Inter-strip capacitance, noise, pick-up, cross-talk, signal efficiency, and fabrication yield have been taken into account in their design and fabrication. Inter-strip capacitance tests taking into account all channel neighbors reveal the important differences between the various designs considered. These tests have been correlated with noise figures obtained in full assembled modules, showing that the tests performed on the bare sensors are a valid tool to estimate the final noise in the full module. The full modules have been subjected to test beam experiments in order to evaluate the incidence of cross-talk, pick-up, and signal loss. The detailed analysis shows no indication of cross-talk or pick-up as no additional hits can be observed in any channel not being hit by the beam above 170 mV threshold, and the signal in those channels is always below 1% of the signal recorded in the channel being hit, above 100 mV threshold. First results on irradiated mini-sensors with embedded pitch adapters do not show any change in the interstrip capacitance measurements with only the first neighbors connected

Charge collection and field profile studies of heavily irradiated strip sensors for the ATLAS inner tracker upgrade

The ATLAS group has evaluated the charge collection in silicon microstrip sensors irradiated up to a fluence of 1×1016 neq/cm2, exceeding the maximum of 1.6×1015 neq/cm2 expected for the strip tracker during the high luminosity LHC (HL-LHC) period including a safety factor of 2. The ATLAS12, n+-on-p type sensor, which is fabricated by Hamamatsu Photonics (HPK) on float zone (FZ) substrates, is the latest barrel sensor prototype. The charge collection from the irradiated 1×1 cm2 barrel test sensors has been evaluated systematically using penetrating β-rays and an Alibava readout system. The data obtained at different measurement sites are compared with each other and with the results obtained from the previous ATLAS07 design. The results are very consistent, in particular, when the deposit charge is normalized by the sensor's active thickness derived from the edge transient current technique (edge-TCT) measurements. The measurements obtained using β-rays are verified to be consistent with the measurements using an electron beam. The edge-TCT is also effective for evaluating the field profiles across the depth. The differences between the irradiated ATLAS07 and ATLAS12 samples have been examined along with the differences among the samples irradiated with different radiation sources: neutrons, protons, and pions. The studies of the bulk properties of the devices show that the devices can yield a sufficiently large signal for the expected fluence range in the HL-LHC, thereby acting as precision tracking sensors

Evaluation of the performance of irradiated silicon strip sensors for the forward detector of the ATLAS Inner Tracker Upgrade

The upgrade to the High-Luminosity LHC foreseen in about ten years represents a great challenge for the ATLAS inner tracker and the silicon strip sensors in the forward region. Several strip sensor designs were developed by the ATLAS collaboration and fabricated by Hamamatsu in order to maintain enough performance in terms of charge collection efficiency and its uniformity throughout the active region. Of particular attention, in the case of a stereo-strip sensor, is the area near the sensor edge where shorter strips were ganged to the complete ones. In this work the electrical and charge collection test results on irradiated miniature sensors with forward geometry are presented. Results from charge collection efficiency measurements show that at the maximum expected fluence, the collected charge is roughly halved with respect to the one obtained prior to irradiation. Laser measurements show a good signal uniformity over the sensor. Ganged strips have a similar efficiency as standard strips