Measurement of Radon Concentration in Drinking Water in Bhiwani District of Haryana

This investigation aims to evaluate the concentration of dissolved radon in drinking water and to assess the associated radiation doses for infants, children and adults in Bhiwani district of Haryana The radon concentrations were measured in 82 drinking water samples collected from 32 villages/towns in the Bhiwani district. The measurements were performed by RAD7, an electronic radon detector manufactured by Durridge Company Inc. The mean radon concentration ranged between 1.3 ± 0.4 and 13.4 ± 2.2 Bq l^-1. The mean radon concentrations from two locations exceeded the maximum contamination level (MCL) of 11 Bq l^-1 recommended by United States Environmental Protection Agency. The total annual effective doses due to ingestion and inhalation of radon in drinking water varied from 10.1 to 104.4 μSv y^-1 for infants, 5.8 to 59.6 μSv y^-1 for children and 6.6 to 67.7 μSv y^-1 for adults and the average values were found to be 46.3, 26.5 and 30.1 μSv y^-1, respectively.     

Thermal structure of the gas-and-ash plume during eruption of Koryak volcano

High resolution thermal cameras were used in observations of gas-and-ash plumes during eruption of the Koryak volcano in March 2009. Our results provide the thermal structure of gas-and-ash flows. The structure of the eruption column consists of several individual plumes. The vertical velocity of plume rise was estimated at 5.5–7 m/s. The eruption column or plume can be conventionally divided into three parts: a highly convective region, a buoyant region, and a region of horizontal motion. The temperature of the plume is higher than that of the surrounding atmosphere by 3–5°C for the horizontal motion region and by about 20°C for the buoyant region. The velocity at the buoyant region is 5–7 m/s. For the boundary between highly convective and buoyant regions, where the plume diameter is known, the vapor mass flow and the heat capacity of the thermal jet flow can be determined from the heat balance equation. The mass flow of the overheated vapor, which has a temperature of 450°C and comprises a gas-and-ash eruption plume, was estimated to be Q = 35 kg/s. The total mass of water vapor over the period of eruption (100 days) is estimated at 3 · 10⁵ t. The total thermal energy of the eruption amounted to 10⁹ MJ.     

Application of analytical hierarchy process (AHP) for flood risk assessment: a case study in Malda district of West Bengal,India

A field experiment was conducted from 2 May 2010 to 1 May 2012 in the Gurbantunggut Desert, the second largest desert in China, to investigate saltation activity and its threshold velocity, and their relations with atmospheric and soil conditions. The results showed that saltation activity occurred more frequently during 08:00–20:00 Local Standard Time in spring and summer, with air temperatures between 20.0 and 29.0 °C, water vapor pressures between 0.6 and 0.9 kPa, soil temperatures between 25.0 and 30.0 °C, and a soil moisture lower than 0.04 m³/m³. At 2 m height, the saltation threshold velocity varied between 11.1 and 13.9 m/s, with a mean of 12.5 m/s. Threshold velocity showed clear seasonal variations in the following sequence: spring (11.7 m/s) < autumn (12.7 m/s) < summer (13.6 m/s). Affected by soil conditions, aeolian sand transport was weak, with an average annual aeolian sand that transported across a section (1.0 m × 2.0 m) of less than 6.0 kg.     

Determination of 3-D Velocity Anomalies of the Nanbei Tectonic Zone of China Based on Local Earthquakes

In this paper, 3-D velocity images of the crust and upper mantle beneath the Nanbei tectonic zone of China are constructed using P-wave travel time residuals of earthquakes, with the data supplied by China's seismic networks and the International Seismic Centre.During the model parameterization in the tomographic inversion the interpolation function of grid node velocities is used as the space function of velocity, and the velocity function is allowed to be discontinuous. The difficulties caused by large memory demand and high computing cost in solving the system of equations are avoided by utilizing the least squares QR decomposition algorithm. Thus, the stability of the algorithm is ensured. Though resolution images are not derived in the inversion process based on the resolution theory of Backus and Gilbert, a covariance resolution method is put forward by the authors. The resolution analyses have proved the reliability of the image results. 3-D ray tracing is conducted to obtain the ray paths in a s     

A Mössbauer study of ferric iron in olivine

Natural and synthetic olivines with ferrous and ferric iron have been studied by Mössbauer spectroscopy. Their spectra exhibit three superimposed quadrupole-split doublets corresponding to Fe²⁺ at M1 and M2 sites and Fe³⁺ at an unidentified position, which is probably M2. The hyperfine parameters of Fe³⁺ at temperatures between 300°C and 450°C are: Δ=0.67–1.23 mm/s, δ=0.04–0.23 mm/s relative to metallic iron, and the full width at half height, HW=0.15–0.43 mm/s. The Fe²⁺ populations of M2 decrease with increasing Fe³⁺ content. However, Fe²⁺ prefers M1 in synthetic olivines, even at high temperatures (800°–1,400°C). In kirschsteinite, Fe²⁺ and Fe³⁺ are exclusively in M1. Fe²⁺/Fe³⁺ ratios estimated from the peak areas are consistent with chemical analyses.     

Celestite (SrSO4(s)) solubility in water,seawater and NaCl solution

Celestite solubility measurements have been conducted in pure water at temperatures from 10 to 90°C. Equilibrium was achieved with respect to a crystalline solid phase from both undersaturated and supersaturated solutions. The measurements show that the solubility undergoes a maximum near 20°C. LogK values for the solubility reaction are adequately described by the following expression over the temperature range 283.15 to 363.15 K: −logK= −35.3106+0.00422837T+318312/T²+14.99586 logT.The following thennodynamic values for the dissolution reaction of SrSO_4(s), at 25°C have been derived: ΔG_R⁰ = 37852 ± 30 Jmol⁻¹ΔH_R⁰ = −1668±920Jmol⁻¹ΔS_R⁰= −132.6±3.2JK^−1mol−1Celestite solubility measurements were also determined in NaCl solutions up to 5 m concentration and from 10 to 40°C. These data are in good agreement with the work of StrÜbel (1966), who reports solubility measurements to temperatures of 100°C.The application of the Pitzer relations and the solubility constants determined in this study to calculate celestite solubility in NaCl solutions yields excellent agreement between predicted values and experimental measurements over the entire range of temperature and NaCl concentration conditions. For the limited number of solubility measurements in seawater-type solutions and mixed-salt brines, the agreement using the Pitzer relations is within three percent of the measured solubility.     

Air-sea exchange of CO2 in the Gulf of Kutch,northern Arabian Sea based on bomb-carbon in corals and tree rings

Radiocarbon analyses were carried out in the annual bands of a 40 year old coral collected from the Gulf of Kutch (22.6°N, 70°E) in the northern Arabian Sea and in the annual rings of a teak tree from Thane (19°14′N, 73°24′E) near Bombay. These measurements were made in order to obtain the rates of air-sea exchange of CO₂ and the advective mixing of water in the Gulf of Kutch. The Δ¹⁴C peak in the Thane tree occurs in the year 1964, with a value of ∼630‰, significantly lower than that of the mean atmospheric Δ¹⁴C of the northern hemisphere (∼ 1000‰). The radiocarbon time series of the coral was modelled considering the supply of carbon and radiocarbon to the gulf through air-sea exchange and advective water transport from the open Arabian Sea. A reasonable fit for the coral data was obtained with an air-sea CO₂ exchange rate of 11–12 mol m⁻² yr⁻¹, and an advective velocity of 28 m yr⁻¹ between the Arabian Sea and the Gulf of Kutch; this was based on a model generated time series for radiocarbon in the Arabian Sea. The deduced velocity (∼ 28 m yr⁻¹) of the advective transport of water between the gulf and the Arabian Sea is much lower than the surface tidal current velocity in this region, but can be understood in terms of net fluxes of carbon and radiocarbon to the gulf to match the observed coral Δ¹⁴C time series.     

Velocity structure and geothermics of the Earth's crust along the European Geotraverse

Crustal isovelocity lines are constructed along the European Geotraverse for the seismic velocities 6.0, 6.4, 7.1 and 7.8 km/s. Using this velocity structure and a correlation between heat generation and seismic velocity for crustal rocks, the contribution of the crust to the surface heat flow density value is calculated. The heat flow density at the Moho varies from 5 to 40 mW/m² from Paleo-Europe in the north to Neo-Europe in the south, while the mantle heat flow density is close to zero beneath the Alps; the temperatures calculated for the Moho are 260°–390°C for Paleo- to Meso-Europe, 420°–520°C for Neo-Europe and 700°C for the mountain-root beneath the Alps.     

Dissociation constants of calcite and CaHC03+ from 0 to 50°C

From conductance measurements, the negative logarithm of the dissociation constant of the CaHCO₃₊ ion pair, pK(CaHCO₃⁺), is 0.7, 1.0 and 1.35 within ±0.05 units at 0, 25 and 60°C, respectively. A revaluation of published and unpublished data yields pK(CaCO₃⁰) ≈ 3.2 at 25°C. Use of these pK's to compute the dissociation constant of calcite (Kc) from published calcite solubility measurements in pure water gives pKc values which increase markedly with ionic strength. However, if the ion pairs are ignored, computed pKc values are nearly constant with ionic strength. All reasonable attempts to eliminate the trend in pKc by adjusting ion activity coefficients, and/or values of K(CaCO₃⁰) failed, so the dilemma remains. Kc values computed from the most reliable published calcite solubility data are in good agreement with such values based on solubility data measured in this study at 5, 15, 35 and 50°C. Study results ignoring ion pairs are accurately represented by the equation log Kc = 13.870 — (3059/T) ?0.04035T, and correspond to ?8.35, ?8.42, and ?8.635 at 0, 25 and 50°C, respectively. The logarithmic expression leads to ΔH_r^o = ?2420 ± 300 cal/mol, ΔCp = ?110 ± 2 cal/deg mol, and ΔS_r^o = ?46.6 ± 1.0 cal/deg mol for the calcite dissociation reaction at 25°C. The dependence of Kc on temperature when CaCO₃⁰ and CaHCO₃⁺ are assumed, is described by log Kc = 13.543 ? (3000/T) ? 0.0401T which yields ?8.39, ?8.47, and -8.70 at 0, 25 and 50°C. This gives ΔH_r^o = ?2585 ± 300 cal/mol, ΔCp = ?109 ± 2 cal/deg mol, and ΔS_r⁰ = ?47.4 ± 1.0 cal/deg mol at 25°C.     

The infinite dilution diffusion coefficient for A1(OH)4− at 25°C

The infinite dilution diffusion coefficient for Al(OH)₄^? necessary to calculate fluxes of dissolved Al between sediments and overlying waters, was determined at 25°C. Measurements were made using the diaphragm-cell method by diffusing Al(OH)₄^? spiked KBr solutions against KCL over a range of ionic strengths. The mean of 9 separate measurements gives 1.04 ± .02 × 10^?5cm²/s as the infinite dilution diffusion coefficient for Al(OH)₄^? at 25°C.     

Treatment of poultry slaughterhouse wastewater in upflow anaerobic filter under low upflow velocity

The wastewater discharged by poultry slaughterhouse industries are characterized mainly by high biochemical oxygen demand, high suspended solids and complex mixture of fats, proteins and fibers requiring systematic treatment prior to disposal. In this study, the performance of an upflow anaerobic filter reactor for treating Indian poultry slaughterhouse wastewater under low upflow velocity of 1.38 m/day at mesophilic temperature (29-35 °C) was investigated. The reactor was inoculated with anaerobic non-granular sludge from an anaerobic reactor treating the poultry slaughterhouse wastewater. The reactor took 147 days for complete start-up with removal efficiencies of total chemical oxygen demand and soluble chemical oxygen demand of 70 and 79 % respectively. The maximum total chemical oxygen demand removal efficiency of 78 % was achieved at an organic loading rate of 10.05 kg/m³/day and at an hydraulic retention time of 12 h. The average methane content varied between 46 and 56 % and methane yield at maximum removal efficiency was 0.24 m³ CH₄/kg COD_removed·day. Sludge granules of 1–2 mm were observed in between the packing media. Scanning electron microscope analysis revealed that sludge granules are composed of clumps of Methanosarcina clustered with less intertwined Methanosaeta fibre of granules. The lower velocity used in this study has achieved better performance of the reactor by creating active microbial formation with stable pH upto an organic loading rate of 14.3 kg/m³/day. This has proved that the poultry slaughterhouse wastewater can be treated using anaerobic filter reactor under low upflow velocity.     

Advanced oxidation of catechol in reverse osmosis concentrate generated in leather wastewater by Cu–graphite electrode

Reverse osmosis (RO) concentrate generated from tannery was treated by advanced electrochemical oxidation using graphite electrodes. Catechol was selected as model organic pollutant in the RO concentrate. The influence of applied current density, catechol concentration, pH, temperature and inner electrode space of electrodes was investigated in electrochemical oxidation system. The optimized conditions were found to be current density (j), 100 mA/cm²; electrolysis time (t _eco), 60 min; pH, 7.0; and temperature, 25 °C at an inner electrode space, 2 cm. The average mass transport coefficient for the removal of catechol as COD was found to be 3.0 × 10^?5 m/s at optimum conditions. Faradic efficiency and specific energy consumption were also calculated for the applied current density. Further, the treatment of catechol was confirmed through Fourier transform infrared spectroscopy. Theoretical evaluation of current density suggested that the removal of catechol was controlled when supplied at above limiting applied current densities and mass transport controlled at lower of limiting current densities.     

Experimental determination of portlandite and brucite solubilities in supercritical H2O

Experimentally reversed portlandite and brucite solubilities were determined between 300° and 600°C and 1 to 3 kbar. In the portlandite runs the molality of Ca decreases with increasing pressure at constant temperature. For instance, at 2 kbar log molalities at 300°, 400°, 500° and 600°C give values of −2.34, −2.71, −3.18 and −4.18, respectively. At 500°C, pressures of 1, 2 and 3 kbar yield values of −4.40, −3.18 and −2.65. Distribution of species in solution can be calculated with the aid of data from Helgeson and co-workers assuming Ca⁺⁺ is the dominant Ca species. These calculated Ca concentrations are within ± 0.2 log units of experimental values in most cases. The solubility reaction is, in all likelihood: 2H⁺ + Ca(OH)₂ ↔a3 Ca⁺⁺ + 2H₂O.Although the computed pH's are close to 2 units greater than neutral, the solutions apparently contained no significant Ca(OH)⁺ or Ca(OH)_2sq.Concentrations of Mg in the brucite runs show a sigmoidal behavior at 2 kbar as a function of temperature with log molalities of Mg of −4.00, −4.28, −4.14 and −4.60 at 350°, 450°, 550° and 600°C, respectively. Values at 1 kbar are lower and decrease monotonically from 350° to 550°C. Based on available thermodynamic data for Mg⁺⁺ it appears that Mg(OH)⁺ is the dominant Mg species in solution. The solubility reaction is proposed to be: H⁺ + Mg(OH)₂↔a3 Mg(OH)⁺ + H₂O.With the aid of data of Helgeson and co-workers values of the equilibrium constant for H₂O + Mg⁺⁺ ↔a3 Mg(OH)⁺ + H⁺ necessary to account for the measured solution compositions can be calculated. These calculations indicate Mg(OH)⁺ becomes dominant at temperatures above 450°C at 2 kbar and above 360°C at 1 kbar at neutral pH.     

Bonding and dynamical phenomena in MgO: A high temperature 17O and 25Mg NMR study

We have measured the isotropic chemical shifts (δ_iso) and the spin-lattice relaxation times (T₁) for ¹⁷O and ²⁵Mg in MgO from room temperature up to 1300° C. The ¹⁷O chemical shifts increase linearly from 47 ppm at room temperature to 57 ppm at 1300° C, and over the same temperature range the ²⁵Mg chemical shift increases linearly from 25 to 27 ppm. These changes are not the result of changes in the bulk magnetic susceptibility of the samples, but may be due to increased orbital overlap which is the result of the increase in thermal vibration of the ions with temperature. In the case of ²⁵Mg, the shift to lower shielding with increasing temperature is opposite to that expected from simple bond length versus chemical shift trends established for the oxides at room temperature. If this is a general phenomenon, high-temperature NMR data may be biased to lower shielding. Spin-lattice relaxation times (T₁) were measured in order to study the energetics of defect motion. T₁'s for ¹⁷O and ²⁵Mg exhibit similar behavior over the range of temperatures studied. Up to 800° C, T₁'s decrease gradually, but above 800° C, T₁'s drop rapidly, with slopes corresponding to apparent activation energies of 192±9 kJ/mol (2.0±0.1 eV) for ¹⁷O and 151±6 kJ/mol (1.56±0.06 eV) for ²⁵Mg. While direct comparison of these activation energies to those derived from diffusion or conductivity measurements is complicated, the similar behavior for both nuclei suggests their relaxation phenomena are related.     

Entrainment of circumpolar water in the Indian Ocean region of the Antarctic

The net influx of the circumpolar water on the western (approximately along 10°E) and eastern (approximately 115°E) boundaries of the Indian Ocean, adopting the method of Montgomery and Stroup is computed on bivariate distribution of potential thermosteric anomaly and salinity to identify the characteristics of the flux. The zonal flux at both the boundaries indicates an alternate strong easterly and westerly flow between 36°S and 45°S, south of which the flow is mainly easterly but weak up to 56°S. At the western boundary the easterly flow is 146 Sv and westerly is 98.07 Sv, while at the eastern boundary (115°E) the corresponding fluxes are 123.46 Sv and 27.20 Sv respectively, indicating a net outflux of 48.33 Sv. This water should have been accounted by the melting of ice and influx of the Equatorial Pacific Ocean Water.     

Phase Relations in the System Pb—Sn—Fe—Sb—S

Phase relations in the system Pb-Sn-Fe-Sb-S were investigated through the diagrams of projecting plane 8x(PbS-SnS-SnS2)from the vertrex point Fe0.96Sb2.04S4.12by vacuum silica tube technique.Experimental results have shown that franckeite has a wide solid solution with substitution of Pb^2 by Sn^2 ,In franckeite s.s.the content of Sn^2 varies from 0 to 4.8 atoms (total metal atoms are 11 atoms per formula) at 500℃ and 0-4.0 atoms at 400℃,respectively,Meanwhile,the content of Sn^4 ranges from 1.3to 2.0 atoms at 500℃ and 1.5-2.1 atoms at 400℃ in franckeite s.s.These results are consistent well with analytic data on natural franckeite.The cylindrite solid solutiopn has a relatively small range with Sn^2 -1.8atoms and Sm^4 =3.2-4.2 atoms per formula at 500℃ and ,Sn^2 =0.5-1.7 atoms and Sm^4 =3.3-4.2 atoms at 400℃ which are comparable with natural cylindrite.The phases coexisting in equilibrium with franckeite s.s. are galena,boulangerite,robinsonite.teallite,SnS,cylindrite.s.s.and synthetic phase Ⅲ ss or I ss.The cylindrite s.s.coexists with SnS2 and the above mentioned phases,but not with galena.teallite and SnS,and probably not with boulangerite in this projecting plane.     

Experimental and numerical analyses of particulate matter concentrations in underground subway station

The purpose of this paper was to perform the experimental and numerical analyses of PM₁₀ and PM_2.5 concentrations in Imam Khomeini (IKH) underground subway station in Tehran. The aim was to provide fundamental data in order to fulfill workers and passengers respiratory health necessities. Experimental measurements was done at three different locations (entrance, middle and exit) inside the platform and also outdoor ambient of the station. The Dust-Trak was applied to measure continuous PM_2.5 and PM₁₀ concentrations at a logging interval of 30 s. The measurements were recorded during rush hours (8:00 am–12:00 pm) for one week per each season from June 2015–June 2016.Moreover, computational fluid dynamic (CFD) simulation was done for the platform of the above station and the necessary boundary conditions were provided through field measurements. Those basic parameters which were considered for numerical analysis of particulate matters concentrations included air velocity, air pressure and turbulence. Furthermore, the piston effect caused by train movement inside the station provided natural ventilation in the platform. The results showed that seasonal measured PM_2.5 and PM₁₀ indoor concentrations had a variety range from 40–98 µg/m³ to 33–102 µg/m³, respectively, and were much higher than national indoor air quality standard levels. Meanwhile, PM_2.5 and PM₁₀ concentrations in the IKH underground subway station were approximately 2.5–2.9 times higher than those in outdoor ambient, respectively. Numerical simulation indicated that the predicted concentrations were underestimated by a factor of 8% in comparison with the measured ones.     

Measured river leakages using conventional streamflow techniques: the case of Souhegan River, New Hampshire, USA

Multiple streamflow measurements were made at coupled discharge measurement stations to quantify rates of aquifer recharge and discharge on two reaches of the Souhegan River, New Hampshire, USA, flowing within a glacial-drift river-valley aquifer. The reaches included a predominantly losing (aquifer recharge) reach and a variable (aquifer recharge and discharge) reach located downstream of the former reach. River leakage, the differential between coupled upstream and downstream streamflow measurements along a reach, varied by almost 30 cubic feet per second (ft³/s) (0.85 m³/s) along the two reaches. The upper reach averaged 3.94 ft³/s (0.11 m³/s) loss whereas the lower reach averaged 4.85 ft³/s (0.14 m³/s) gain. At the upper reach, 13 losses were measured out of 19 coupled measurements. At the lower reach, ten out of 13 coupled measurements indicated gains in flow and suggest that this reach is primarily a gaining river reach. An important factor in river leakage appears to be antecedent trends in river stage. At the upper reach, gains were measured only during periods of declining river stage. Conversely, at the lower reach, streamflow loss was measured primarily during periods of rising river stage. Although some tendencies exist, several factors complicate the analysis of river leakage, most notably the inaccuracies in computed stream discharge.     

Radon distributions in the Hail Region of Northern Saudi Arabia

Indoor radon measurements were carried out in a total of 420 dwellings and 17 schools in Hail region of Saudi Arabia, using NTDs based radon dosimeters. The duration of the measurements was one year, from April 2008 to April 2009. The indoor radon concentrations varied from 4 to 513 Bq/m³ with an overall average of 45 Bq/m³ for all surveyed dwellings. These passive measurements were confirmed by the active measurements. The anomalous concentrations above 200 Bq/m³ were observed in 13 dwellings, representing 3.1 % of the total surveyed dwellings. In Inbowan village alone, it was found that 7.6 % of the dwellings have indoor radon concentration above 200 Bq/m³. The highest average indoor radon concentration of 64 Bq/m³ was found in Inbowan village while the lowest average of 24 Bq/m³ was found in Majasah village. The city of Hail showed an average indoor radon concentration of 49 Bq/m³. The average indoor radon concentration in one area located at the edge of the Aja Mountain in Hail city was 111 Bq/m³. The elevated indoor radon concentrations in many dwellings in the Hail region, prompted us to measure outdoor ground radon in such locations using gas monitor. It was found that radon concentrations at a depth of 0.5 m varied significantly from place to place ranging from 1.2 to 177 kBq/m³. The outdoor radon concentrations are generally correlated with the indoor radon measurements. Radon exhalations from construction materials and soil samples from the Hail region were also measured. It was found that radon exhalations from soil samples are higher than that of construction materials by a factor of at least 3 and reaching up to 11. These results indicate that soil is the main source of indoor radon. Geological interpretations of the results are also given.     

Anelasticity and microcreep in polycrystalline MgO at high temperature: an exploratory study

 The frequency dependence of the shear modulus and dissipation in polycrystalline MgO has been determined at high temperature using both microcreep (ɛ = 10⁻⁴) and seismic frequency forced-oscillation (ɛ = 10⁻⁵) measurements. The frequency-dependent and time-dependent data have been described in terms of the elastic, anelastic and viscous components of deformation using the Andrade model. The forced-oscillation measurements show that for temperatures above 700 °C the shear modulus begins to decrease dramatically and the modulus becomes frequency-dependent with increasing temperature. This is accompanied by an increase in dissipation, which also becomes frequency-dependent. The microcreep measurements resolve this frequency-dependent behaviour into an anelastic regime from 700–1050 °C, and a viscoelastic regime from 1100–1300 °C. At 1300 °C, the seismic frequency shear wave speed is ∼60% of the extrapolated low-temperature frequency-independent value, and the dissipation has risen to Q ⁻¹ = 10⁻¹ from 10⁻³ at temperatures below 600 °C. The mechanism by which this frequency-dependent rheology occurs appears to be diffusional creep, which produces viscous slip on the grain boundaries. It is proposed that the anelastic behaviour is due to viscous slip occurring on segments of grain boundaries, with the viscous deformation being accommodated by elastic distortion of adjacent unslipped regions of the grain boundary. At higher temperatures, slippage occurs across the entire grain boundary and viscoelastic behaviour begins to occur. Received: 11 April 2002 / Accepted: 9 January 2003 Acknowledgements Samples were precision-ground by Andrew Wilson, and polished sections prepared by Harri Kokkonen, who also did the SEM work. Uli Faul calculated the volume fraction of grain sizes. The density measurements were done by Lara Weston.