Metrology aspects (sampling, storage, transportation, and measurement) of radon in water

Background: Radon can enter homes using water during normal household activities, and it contributes to increasing the radon concentration of the adjacent space. Because of its gaseous form, it can easily escape during one of the procedures preceding its measurement (sampling, transport, and storage) and during its measurement resulting in its underestimation, which could lead to an underestimated dose calculation. Objectives: This study focused on quantifying and evaluating radon losses during sampling, transporting, and storing radon in water samples. Also, in terms of measuring radon in water activity concentration, two emanometry methods were compared to the direct method of gamma-ray spectrometry. Design and Methods: In terms of sampling, two methods were examined and compared. Road transport effect on radon losses was studied by measuring the radon in water concentration of radon-rich samples before and after their transportation at different ambient temperatures. Different materials (PET, glass, aluminum) were examined for their radon tightness by repetitive measurements and interpolation of the recorded data. Also, the effect of ambient temperature (1 to 40°C) on radon losses was studied during the storage phase. To compare radon in water measuring methods, water from the original bottle was poured carefully into the different sample containers that each method requires and measured by each method. Results and Conclusions: Sampling is the factor that can cause the most significant radon losses. Radon tightness investigation of different materials showed no significant differences in their ability to preserve radon inside the container, as their fitting curves followed the literature radon decay curve. Ambient temperature (1 to 40 °C) did not appear to affect radon losses during the storage phase. Unlike the storage phase, significant radon losses were observed during road transport at ambient temperatures of 31°C and above. Therefore, measures should be taken to avoid radon losses for ambient temperatures of 31°C and above when road transport is considered (e.g., using thermally insulated boxes and cooling elements). From the comparison of the two emanometry methods with gamma-ray spectrometry, it was found that all methods provide equal results within standard uncertainties

Time variation of radon in tap water in locations of a Greek area with geological background for elevated radon-in-water concentrations and correlation study between radon, gross alpha, uranium, and radium concentrations

Background: Radon (222Rn), a naturally occurring radioactive gas, dissolves in water, and it can be found in elevated concentrations in public water supplies when water originates from ground sources in areas rich in uranium. An area of great interest for measuring radon-in-water is the Migdonia basin in Northern Greece due to its geological background and because all of its villages are supplied with water from boreholes. Objectives: The main aim of this paper was to study the time variation of radon in tap water activity concentration in nine villages of the Migdonia basin supplied with water from boreholes and to determine factors that may affect it. Radon in water correlation between the source (borehole) and the consumption point (tap) was studied for some villages. Also, the correlation among radon, gross alpha, beta, uranium (238U), and radium (226Ra) activity concentration in water was studied. Design and methods: Water samples were collected and measured for their radon activity concentration from 66 villages in the Migdonia basin in order to find places with relatively high radon concentrations. The time variation of radon-in-water was studied for villages that showed relatively high radon concentrations for 3 to 4 years (2018–2022). All samples were measured for their 222Rn activity concentration using gamma-ray spectrometry. Water samples were also analyzed for their gross alpha, beta, and uranium isotopes activity concentration. Results and conclusions: Average radon in tap water activity concentrations measured in the area ranged from background concentrations to 185 Bq L-1. The corresponding annual effective doses from waterborne radon inhalation using both UNSCEAR and ICRP dose conversion factors ranged from 0.01 to 0.466 mSv y-1 and from 0.02 to 0.868 mSv y-1, respectively, while radon ingestion annual effective doses varied from 0.007 to 0.324 mSv y-1. Time variation of radon activity concentration in tap water for villages supplied from one borehole or a constant number of boreholes showed relatively low standard deviations (<24 percent) at a coverage factor of k = 1. Those deviations are probably caused by the time variation of boreholes’ radon concentration and water demand changes. A significant decline in radon concentration from the source (borehole) to the consumption point (tap water) was observed. Therefore, sampling should be performed at the consumption point. However, knowing the supplying borehole concentration is useful as it determines the potential for radon in drinking water. No apparent correlation was found among radon, gross alpha, beta, uranium, and radium concentrations in water. However, in some cases, remedial actions (withdrawal of boreholes) for uranium concentration also decreased radon concentration

JOLED: a mid-air display based on electrostatic rotation of levitated Janus objects

We present JOLED, a mid-air display for interactive physical visualization using Janus objects as physical voxels. The Janus objects have special surfaces that have two or more asymmetric physical properties at different areas. In JOLED, they are levitated in mid-air and controllably rotated to reveal their different physical properties. We made voxels by coating the hemispheres of expanded polystyrene beads with different materials, and applied a thin patch of titanium dioxide to induce electrostatic charge on them. Transparent indium tin oxide electrodes are used around the levitation volume to create a tailored electric field to control the orientation of the voxels. We propose a novel method to control the angular position of individual voxels in a grid using electrostatic rotation and their 3D position using acoustic levitation. We present a display in which voxels can be flipped independently, and two mid-air physical games with a voxel as the playable character that moves in 3D across other physical structures and rotates to reflect its status in the games. We demonstrate a voxel update speed of 37.8 ms/flip, which is video-rate

Cross-cultural differences in early caregiving: levels of mind-mindedness and instruction in UK and India

IntroductionMost studies on parenting and its role in child development are conducted in Western countries, but it cannot be assumed that characteristics of parental practices are similar in non-Western settings. Research characterizing cultural differences in parenting is required to inform the focus of studies designed to test differential outcomes from such practices in children over time and across cultures. The present cross-cultural study examined differences in maternal speech during mother–child interactions, and, specifically, in the use of mind-mindedness, instruction and control, and the expression of warmth (i.e., positive comments).MethodsWe observed 100 dyads (50 from the UK and 50 from India) during mother-infant play interactions at 7 months. Maternal speech was transcribed and translated prior to independent coding, and this was coded using established measures together with a newly developed measure of “Instructions”.ResultsSubstantially large differences between UK and Indian mothers were observed. Compared with UK mothers, Indian mothers made fewer mind-minded comments about their infants, and they issued more instructions and made more controlling and positive comments. Findings from this study might reflect cultural differences in how parental style might be expressed according to cultural priorities and values.ConclusionsThe implications of these very large differences in parenting across cultures for child development remain to be investigated and are discussed in the present paper

Improving Crop Yield and Nutrient Use Efficiency via Biofertilization - A Global Meta-analysis

The application of microbial inoculants (biofertilizers) is a promising technology for future sustainable farming systems in view of rapidly decreasing phosphorus stocks and the need to more efficiently use available nitrogen (N). Various microbial taxa are currently used as biofertilizers, based on their capacity to access nutrients from fertilizers and soil stocks, to fix atmospheric nitrogen, to improve water uptake or to act as biocontrol agents. Despite the existence of a considerable knowledge on effects of specific taxa of biofertilizers, a comprehensive quantitative assessment of the performance of biofertilizers with different traits such as phosphorus solubilization and N fixation applied to various crops at a global scale is missing. We conducted a meta-analysis to quantify benefits of biofertilizers in terms of yield increase, nitrogen and phosphorus use efficiency, based on 171 peer reviewed publications that met eligibility criteria. Major findings are: (i) the superiority of biofertilizer performance in dry climates over other climatic regions (yield response: dry climate +20.0 ± 1.7%, tropical climate +14.9 ± 1.2%, oceanic climate +10.0 ± 3.7%, continental climate +8.5 ± 2.4%); (ii) meta-regression analyses revealed that yield response due to biofertilizer application was generally small at low soil P levels; efficacy increased along higher soil P levels in the order arbuscular mycorrhizal fungi (AMF), P solubilizers, and N fixers; (iii) meta-regressions showed that the success of inoculation with AMF was greater at low organic matter content and at neutral pH. Our comprehensive analysis provides a basis and guidance for proper choice and application of biofertilizers

Assessing the effectiveness of a three-stage on-farm biobed in treating pesticide contaminated wastewater

Agricultural point source pesticide pollution arising from contaminated machinery washings and accidental spillages pose a significant threat to river water and groundwater quality. In this study, we assess the effectiveness of a three-stage on-farm biobed for treating pesticide contaminated waste water from a large (20 km2) commercial arable estate. The facility consisted of an enclosed machinery wash-down unit (stage 1), a 49 m2 lined compost-straw-topsoil biobed (stage 2), and a 200 m2 drainage field with a trickle irrigation system (stage 3). Pesticide concentrations were analysed in water samples collected fortnightly between November 2013 and November 2015 from the biobed input and output sumps and from 20 porous pots buried at 45 cm and 90 cm depth within the drainage field. The results revealed that the biobed removed 68–98% of individual pesticides within the contaminated washings, with mean total pesticide concentrations reducing by 91.6% between the biobed input and output sumps. Drainage field irrigation removed a further 68–99% of individual pesticides, with total mean pesticide concentrations reducing by 98.4% and 97.2% in the 45 cm and 90 cm depth porous pots, respectively. The average total pesticide concentration at 45 cm depth in the drainage field (57 µg L-1) was 760 times lower than the mean concentration recorded in the input sump (43,334 µg L-1). There was no evidence of seasonality in the efficiency of biobed pesticide removal, nor was there evidence of a decline in removal efficiency over the two-year monitoring period. However, higher mean total pesticide concentrations at 90 cm (102 µg L-1) relative to 45 cm (57 µg L-1) depth indicated an accumulation of pesticide residues deeper within the soil profile. Overall, the results presented here demonstrate that a three-stage biobed can successfully reduce pesticide pollution risk from contaminated machinery washings on a commercial farm