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PM10 samples were collected to characterize the seasonal and annual trends of carbonaceous content in PM10 at an urban site of megacity Delhi, India from January 2010 to December 2017. Organic carbon (OC) and elemental carbon (EC) concentrations were quantified by thermal-optical transmission (TOT) method of PM10 samples collected at Delhi. The average concentrations of PM10, OC, EC and TCA (total carbonaceous aerosol) were 222 ± 87 (range: 48.2-583.8 μg m−3), 25.6 ± 14.0 (range: 4.2-82.5 μg m−3), 8.7 ± 5.8 (range: 0.8-35.6 μg m−3) and 54.7 ± 30.6 μg m−3 (range: 8.4-175.2 μg m−3), respectively during entire sampling period. The average secondary organic carbon (SOC) concentration ranged from 2.5-9.1 μg m−3 in PM10, accounting from 14 to 28% of total OC mass concentration of PM10. Significant seasonal variations were recorded in concentrations of PM10, OC, EC and TCA with maxima during winter and minima during monsoon seasons. In the present study, the positive linear trend between OC and EC were recorded during winter (R2 = 0.53), summer (R2 = 0.59) and monsoon (R2 = 0.78) seasons. This behaviour suggests the contribution of similar sources and common atmospheric processes in both the fractions. OC/EC weight ratio suggested that vehicular emissions, fossil fuel combustion and biomass burning could be the major sources of carbonaceous aerosols of PM10 at the megacity Delhi, India. Trajectory analysis indicates that the air mass approches to the sampling site is mainly from Indo Gangetic plain (IGP) region (Uttar Pradesh, Haryana and Punjab etc.), Thar desert, Afghanistan, Pakistan and surrounding areas. [ABSTRACT FROM AUTHOR]

PM2.5 hadn’t received much attention until 2013 when people started to understand its dreadful impacts to human health. According to the meteorological monitoring data of PM2.5 from September 9, 2016 to September 9, 2017 in Fuling district, Chongqing, this paper analyzed the impact of temperature, humidity and the power of wind on PM2.5. Using the mathematical model of BP neural networks, a prediction model based on satellite remote sensing data for the pollutant concentration in regional scale was explored, and the forecast for Fuling 3-h PM2.5 concentration was realized. The algorithm effectively establishes the correlation between AOD and PM2.5 concentration, and it suppresses the overfitting phenomenon very well, as well as it makes up the limitation of machine learning for single site prediction. [ABSTRACT FROM AUTHOR]

The need to improve the State Primary Special Standard of the unit of mass concentration of particles in aerodispersed media GET 164-2003 is demonstrated. The structure of the standard is considered, methods of reproduction and transmission of the unit are described, and the basic metrological characteristics of the standard are presented. The improved standard GET 164-2016 is presented. A comparative analysis of the characteristics of the two standards is performed. [ABSTRACT FROM AUTHOR]

We present an improved mascon approach to transform monthly spherical harmonic solutions based on GRACE satellite data into mass anomaly estimates in Greenland. The GRACE-based spherical harmonic coefficients are used to synthesize gravity anomalies at satellite altitude, which are then inverted into mass anomalies per mascon. The limited spectral content of the gravity anomalies is properly accounted for by applying a low-pass filter as part of the inversion procedure to make the functional model spectrally consistent with the data. The full error covariance matrices of the monthly GRACE solutions are properly propagated using the law of covariance propagation. Using numerical experiments, we demonstrate the importance of a proper data weighting and of the spectral consistency between functional model and data. The developed methodology is applied to process real GRACE level-2 data (CSR RL05). The obtained mass anomaly estimates are integrated over five drainage systems, as well as over entire Greenland. We find that the statistically optimal data weighting reduces random noise by 35–69%, depending on the drainage system. The obtained mass anomaly time-series are de-trended to eliminate the contribution of ice discharge and are compared with de-trended surface mass balance (SMB) time-series computed with the Regional Atmospheric Climate Model (RACMO 2.3). We show that when using a statistically optimal data weighting in GRACE data processing, the discrepancies between GRACE-based estimates of SMB and modelled SMB are reduced by 24–47%. [ABSTRACT FROM AUTHOR]

Ultraluminous infrared galaxies with total luminosities an order of magnitude greater than that of our galaxy over wavelengths of λλ = 10-800 μm are characterized by a high mass concentration of dust. Because of this, the optical thickness of the interstellar gas is extremely high, especially in the central regions of the galaxies, ranging from 1 at millimeter wavelengths to 104 in the visible. The average temperature of the dust in them is about T=30 K, but the variations from one galaxy to another are large, with T=20-70 K. The main source of dust in these galaxies seems to be type II supernova bursts and the main heating source is stars. In addition, given that shock waves from supernovae are an effective mechanism for destruction of interstellar dust in our galaxy and the high optical thickness of the gas with respect to the heating radiation from the stars, this conclusion merits detailed analysis. This paper provides estimates of the dust mass balance and details of its heating in these galaxies based on the example of the ultraluminous galaxy closest to us, Arp 220. It is shown that when supernovae are dominant in the production and destruction of dust in the interstellar gas, the resultant dust mass fraction is close to the observed value for Arp 220. It is also found that the observed stellar population of this galaxy can support a high ( T ≃ 67 K ) temperature if the dust in its central region is concentrated in small, dense (n~10 cm) clouds with radii of 0.003 ≲ pc. Mechanisms capable of maintaining an interstellar gas structure in this state are discussed. [ABSTRACT FROM AUTHOR]

Peltier-element-based adiabatic scanning calorimetry was used to obtain equilibrium enthalpy and heat capacity curves for pure water and water-NaCl mixtures, up to the eutectic mass concentration of 23.2%, in the temperature range from -30 to $$5\,^\circ {\hbox {C}}$$ , including both the eutectic and the ordinary ice melting. From these equilibrium data, information about the transition temperatures and the heats of fusion was extracted. The transition temperatures are consistent with literature data for the phase diagram. The heats of fusion were rescaled with respect to the fraction of the sample that changes phase at each transition. These rescaled values for the eutectic transition are independent of the overall salt concentration, whereas for the ice melting there is an indication of slight decrease with increasing salt concentration. [ABSTRACT FROM AUTHOR]

With the widespread use of titanium dioxide (TiO) human exposure is inevitable, but the exposure data on TiO are still limited. This study adopted off-line filter-based sampling combined with real-time activity-based monitoring to measure the concentrations in a workplace manufacturing TiO (primary diameter: 194 ± 108 nm). Mass concentrations (MCs) of aerosol particles in the packaging workshop (total dust: 3.17 mg/m, nano dust: 1.22 mg/m) were much higher than those in the milling workshop (total dust: 0.79 mg/m, nano dust: 0.31 mg/m) and executive office (total dust: 0.44 mg/m, nano dust: 0.19 mg/m). However, the MCs of TiO were at a relatively low level in the packaging workshop (total TiO: 46.4 μg/m, nano TiO: 16.7 μg/m) and milling workshop (total TiO: 39.4 μg/m, nano TiO: 19.4 μg/m) by ICP-MS. The number concentration (NC), surface area concentration (SAC) of aerosol particles potentially deposited in alveolar (SAC), and tracheobronchial (SAC) regions of lungs in the packaging workshop were (1.04 ± 0.89) × 10 particles/cm, 414.49 ± 395.07, and 86.01 ± 83.18 μm/cm, respectively, which were all significantly higher than those of the milling workshop [(0.12 ± 0.40) × 10 particles/cm, 75.38 ± 45.23, and 17.60 ± 9.22 μm/cm, respectively] as well as executive office and outdoor background ( p < 0.05). Activity-related characteristics were found in both workshops, and the time-variant characteristics showed very similar trends for 3 days in the packaging workshop. Our study provides important data of TiO particles exposure in the workplace. [ABSTRACT FROM AUTHOR]

The problem of the membrane separation of a helium-methane mixture containing 0.1 wt % He, which imitates the composition of a helium-rich natural gas field, has been numerically analyzed. The helium and methane flux distribution along the length of a flat-sheet membrane module have been calculated. The distribution of the average mass concentration of helium in the channels is presented. The gas pumping expenditures have been estimated. The optimal working parameters of the gas mixture have been determined. Heating the mixture above 400 K does not enhance the helium-methane separation efficiency. [ABSTRACT FROM AUTHOR]

The aim of this paper is to analyze the temporal variability of Particulate Matter mass concentrations in connection with air circulation, for eight rural sites situated in the Central and Eastern parts of Europe. The stations from Poland, Hungary and Romania are rural stations without sources of pollutants. The analysis covers four winters, between December 2004 and February 2008. The pollution episodes were selected to explain air circulation influence. The results show that the causes of pollution were local, due to high mean sea level pressure and the blocking, as air circulation on large scale, was dominant in the cases of enhanced pollution in the selected area. [ABSTRACT FROM AUTHOR]

The problem of the concentration of mass for two-dimensional (2D) and three-dimensional (3D) cases is considered. The problem is stated for a square and a cube and is solved by the method of statistical regularization, including the minimization of the discrepancy and Monte Carlo testing for constructing the sought densities. [ABSTRACT FROM AUTHOR]

A methodology to purify a Ho solution has been developed by a combination of activity and mass concentration measurements in order to further determine the Ho half-life. The isobaric interference at m/ q ≃ 166 requires Ho purification from non-natural Er with a high purification degree due to the large amount of Ho as opposed to Er. The Ho/Er separation was achieved using high-performance liquid chromatography on a semi-preparative column followed by purification on gravitational chromatography. The efficiency of the separation was evaluated after precise determination of the Er isotopic composition. The purification methodology enabled to separate Ho from Er. [ABSTRACT FROM AUTHOR]

We study blow-up, global existence and ground state solutions for the N-coupled focusing nonlinear Schrödinger equations. Firstly, using the Nehari manifold approach and some variational techniques, the existence of ground state solutions to the equations (CNLS) is established. Secondly, under certain conditions, finite time blow-up phenomena of the solutions is derived. Finally, by introducing a refined version of compactness lemma, the L concentration for the blow-up solutions is obtained. [ABSTRACT FROM AUTHOR]

This study presents the performance evaluation of a novel denuder-equipped PM (particles having aerodynamic diameter less than 1 μm) sampler, tested during fog-dominated wintertime, in the city of Kanpur, India. One PM sampler and one denuder-equipped PM sampler were co-located to collect ambient PM for 25 days. The mean PM mass concentration measured on foggy days with the PM sampler and the denuder-equipped PM sampler was found to be 165.95 and 135.48 μg/m, respectively. The mean PM mass concentration measured on clear days with the PM sampler and the denuder-equipped PM sampler was observed to be 159.66 and 125.14 μg/m, respectively. The mass concentration with denuder-fitted PM sampler for both foggy and clear days was always found less than the PM sampler. The same drift was observed in the concentrations of water-soluble ions and water-soluble organic carbon (WSOC). Moreover, it was observed that the use of denuder leads to a significant reduction in the PM positive artifact. The difference in the concentration of chemical species obtained by two samplers indicates that the PM sampler without denuder had overestimated the concentrations of chemical species in a worst-case scenario by almost 40 %. Denuder-fitted PM sampler can serve as a useful sampling tool in estimating the true values for nitrate, ammonium, potassium, sodium and WSOC present in the ambient PM. [ABSTRACT FROM AUTHOR]

We consider two-dimensional Bose-Einstein condensates with attractive interaction, described by the Gross-Pitaevskii functional. Minimizers of this functional exist only if the interaction strength a satisfies $${a < a^* = \|Q\|_2^2}$$ , where Q is the unique positive radial solution of $${\Delta u - u + u^3 = 0}$$ in $${\mathbb{R}^2}$$ . We present a detailed analysis of the behavior of minimizers as a approaches a*, where all the mass concentrates at a global minimum of the trapping potential. [ABSTRACT FROM AUTHOR]

The use of an optical dust meter, based on the scattering of light by the dust particles, is proposed to suppress the nonrespirable fraction when measuring its mass concentration in the operating medium. The method improves the separation of the dust by replacing the mechanical parts of the dust meter (the cyclone) by electronic signal processing. [ABSTRACT FROM AUTHOR]

Results are presented of monitoring measurements of the mass concentration of PM (particles with the size of less than 10 μm) and PM (less than 2.5 μm) fine-dispersed aerosol fractions at the Sainshand and Zamyn-Üüd stations located in the Gobi Desert of Mongolia. Revealed are the annual variations of the mass concentration of PM and PM fine-dispersed aerosol fractions at these stations in 2008. The maximum values of monthly mean concentration during the year were observed in May in the period of dust storms. On the days with the steady calm weather, the mass concentrations of PM and PM varied within 5-8 μg/m (PM) and 3-5 μg/m (PM) at the Sainshand station. During the dust storms, the maximum values of concentration exceeded 1400 μg/m (PM) and 380 μg/m (PM) that is by 28 (PM) and 15 (PM) times higher than the maximum permissible concentration for the European Union. Results are given of studying the frequency and duration of dust storms in recent 20 years (1991-2010) in the Eastern Gobi Desert. [ABSTRACT FROM AUTHOR]

Methods of investigation of the gravitational field of the Moon on the basis of continuous wavelet-transformation are analyzed. The obtained spectral characteristics are used for explanation of differences between mascons of the visible and invisible sides of the Moon. [ABSTRACT FROM AUTHOR]

While the GRACE (Gravity Recovery and Climate Experiment) satellite mission is of great significance in understanding various branches of Earth sciences, the quality of GRACE monthly products can be unsatisfactory due to strong longitudinal stripe-pattern errors and other flaws. Based on corrected GRACE Mascon (mass concentration) gridded mass transport time series and updated LDCgam (Least Difference Combination global angular momenta) data, we present a new set of monthly gravity models called LDCmgm90, in the form of Stokes coefficients with order and degree both up to 90. The LDCgam inputs are developed by assimilating degree-2 Stokes coefficients from various versions of GRACE (including Mascon products) and SLR (Satellite Laser Ranging) monthly gravity data into combinations of outputs from various global atmospheric, oceanic, and hydrological circulation models, under the constraints of accurately measured Earth orientation parameters in the Least Difference Combination (LDC) scheme. Taking advantages of the relative strengths of the various input solutions, the LDCmgm90 is free of stripes and some other flaws of classical GRACE products. Measurement(s) Stokes coefficient • Coefficient Technology Type(s) spherical harmonic expansion • least difference combination • computational modeling technique Sample Characteristic - Environment climate system Sample Characteristic - Location Earth (planet) Machine-accessible metadata file describing the reported data: 10.6084/m9.figshare.9924929 [ABSTRACT FROM AUTHOR]

Limited studies have reported on in-vitro analysis of PM2.5 but as far as the authors are aware, bioaccessibility of PM2.5 in artificial lysosomal fluid (ALF) has not been linked to urban development models before. The Brazilian cities Manaus (Amazon) and Curitiba (South region) have different geographical locations, climates, and urban development strategies. Manaus drives its industrialization using the free trade zone policy and Curitiba adopted a services centered economy driven by sustainability. Therefore, these two cities were used to illustrate the influence that these different models have on PM2.5in vitro profile. We compared PM2.5 mass concentrations and the average total elemental and bioaccessible profiles for Cu, Cr, Mn, and Pb. The total average elemental concentrations followed Mn > Pb > Cu > Cr in Manaus and Pb > Mn > Cu > Cr in Curitiba. Mn had the lowest solubility while Cu showed the highest bioaccessibility (100%) and was significantly higher in Curitiba than Manaus. Cr and Pb had higher bioaccessibility in Manaus than Curitiba. Despite similar mass concentrations, the public health risk in Manaus was higher than in Curitiba indicating that the free trade zone had a profound effect on the emission levels and sources of airborne PM. These findings illustrate the importance of adopting sustainable air quality strategies in urban planning. [ABSTRACT FROM AUTHOR]