12 research outputs found
Spores of puffball fungus Lycoperdon pyriforme as a reference standard of stable monodisperse aerosol for calibration of optical instruments
Advanced air quality control requires real-time monitoring of particulate matter size and concentration, which can only be done using optical instruments. However, such techniques need regular calibration with reference samples. In this study, we suggest that puffball fungus (Lycoperdon pyriforme) spores can be utilized as a reference standard having a monodisperse size distribution. We compare the Lycoperdon pyriforme spores with the other commonly used reference samples, such as Al2O3 powder and polystyrene latex (PSL) microspheres. Here we demonstrate that the puffball spores do not coagulate and, thus, maintain the same particle size in the aerosol state for at least 15 minutes, which is enough for instrument calibration. Moreover, the puffball mushrooms can be stored for several years and no agglomeration of the spores occurs. They are also much cheaper than other calibration samples and no additional devices are needed for aerosol generation since the fungal fruiting body acts as an atomizer itself. The aforementioned features make the fungal spores a highly promising substance for calibration and validation of particle size analyzers, which outperforms the existing, artificially produced particles for aerosol sampling. Furthermore, the L. pyriforme spores are convenient for basic research and development of new optical measurement techniques, taking into account their uniform particle size and absent coagulation in the aeroso
Symmetry in Aerosol Mechanics: Review
The present review is concerned with the motion of aerosol particles, including that under the exposure to external fields, with special focus being put on the problems related to the similarity theory and invariants that manifest themselves as symmetry in physics. Research on the mechanics of aerosols is extremely important for managing environmental practices. Ultrasonic and electrostatic effects are used in technological processes for cleaning industrial aerosol emissions. In addition, aerosol systems are commonly used to prevent emergency situations (fire extinguishing, fog deposition). Understanding these processes requires knowledge of aerosol mechanics. At the same time, fundamental laws of particulate matter behavior have not been established until now, especially in the presence of external fields. In this paper, we consider the main similarity criteria that are applied for aerosol description. The motion of aerosol particles in the gravitational, electric, and ultrasonic fields is described. The results from studies into acoustic and electrostatic aerosol coagulations are presented herein
Symmetry in Aerosol Mechanics: Review
The present review is concerned with the motion of aerosol particles, including that under the exposure to external fields, with special focus being put on the problems related to the similarity theory and invariants that manifest themselves as symmetry in physics. Research on the mechanics of aerosols is extremely important for managing environmental practices. Ultrasonic and electrostatic effects are used in technological processes for cleaning industrial aerosol emissions. In addition, aerosol systems are commonly used to prevent emergency situations (fire extinguishing, fog deposition). Understanding these processes requires knowledge of aerosol mechanics. At the same time, fundamental laws of particulate matter behavior have not been established until now, especially in the presence of external fields. In this paper, we consider the main similarity criteria that are applied for aerosol description. The motion of aerosol particles in the gravitational, electric, and ultrasonic fields is described. The results from studies into acoustic and electrostatic aerosol coagulations are presented herein
A mathematical model for evaporation of explosive thin film
Here we develop a mathematical model for evaporation of an explosive thin film. Such an objective stems from the problem of trace explosive detection by techniques based on explosive vapor recording. In particular, we have previously devised an instrumentation system for standoff trace explosive detection by the active spectral imaging method. To determine the applicability limits of remote trace explosive detection methods, one should understand the regularities of evaporation dynamics of an explosive thin film, depending on explosive properties, film geometry (thickness, surface area), and ambient conditions. The mathematical model relies on the Hertz-Knudsen- Langmuir equation for evaporation rate and allows for heat exchange between the surface and ambient gas and for heat loss due to evaporation. The fact that phase transition temperature in a thin film is lower than that in a large volume of an explosive was also taken into account. The parametric study of the model was performed. The basic parameters and their variation range affecting the film evaporation rate were identified. Estimations were done for the substance mass in air during the evaporation of explosive thin films within a wide range of the parameters used. Conclusions were made on the applicability limits of trace explosive detection optical methods
IN-SITU MONITORING ALUMINA DURING ALUMINIUM ELECTROLYTIC PRODUCTION
Alumina content in electrolysis cells for aluminum production is one of the most important and poorly controlled parameters. In order to check the current value of alumina content as well as the dissolution of alumina in industrial electrolytes (NaF-AlF3-CaF2-Al2O3), a novel electrochemical sensor was proposed. It was comprised of a carbon working electrode and a counter electrode interacting with aluminum. The sensor was easy to manufacture, and it allowed reducing the measurement error associated with back reactions at the working electrode. The novel approach was considered on an example of dissolving the alumina in the NaF-AlF3-(5 wt%)CaF2 melt ([NaF]/[AlF3] = 2.1 mol/mol) containing alumina (Al2O3) in amount of 0.69-4.51 wt% at 995 °C in conditions of natural and forced convection. It was found that the alumina solubility in the studied melt was 4.51 wt%. Depending on the initial content of alumina in the melt and convection conditions, its dissolution rate varied up to 0.36 mol/s·m3
Aerosol cloud propagation in a closed space
This paper presents the results of an experimental–theoretical investigation of the evolution of a cloud of aerosol particles in a closed space obtained by the shock-wave method. It has been shown that the prevailing propagation mechanism of aerosol particles of diameter 1–7.5 μm is convective diffusion. For the considered class of aerosols, the effective value of the convective diffusion coeffi cient in a closed space has been determined
Aerosol cloud propagation in a closed space
This paper presents the results of an experimental–theoretical investigation of the evolution of a cloud of aerosol particles in a closed space obtained by the shock-wave method. It has been shown that the prevailing propagation mechanism of aerosol particles of diameter 1–7.5 μm is convective diffusion. For the considered class of aerosols, the effective value of the convective diffusion coeffi cient in a closed space has been determined
Gamma-Synuclein Dysfunction Causes Autoantibody Formation in Glaucoma Patients and Dysregulation of Intraocular Pressure in Mice
Dysregulation of intraocular pressure (IOP) is one of the main risk factors for glaucoma. γ-synuclein is a member of the synuclein family of widely expressed synaptic proteins within the central nervous system that are implicated in certain types of neurodegeneration. γ-synuclein expression and localization changes in the retina and optic nerve of patients with glaucoma. However, the mechanisms by which γ-synuclein could contribute to glaucoma are poorly understood. We assessed the presence of autoantibodies to γ-synuclein in the blood serum of patients with primary open-angle glaucoma (POAG) by immunoblotting. A positive reaction was detected for five out of 25 patients (20%) with POAG. Autoantibodies to γ-synuclein were not detected in a group of patients without glaucoma. We studied the dynamics of IOP in response to IOP regulators in knockout mice (γ-KO) to understand a possible link between γ-synuclein dysfunction and glaucoma-related pathophysiological changes. The most prominent decrease of IOP in γ-KO mice was observed after the instillation of 1% phenylephrine and 10% dopamine. The total protein concentration in tear fluid of γ-KO mice was approximately two times higher than that of wild-type mice, and the activity of neurodegeneration-linked protein α2-macroglobulin was reduced. Therefore, γ-synuclein dysfunction contributes to pathological processes in glaucoma, including dysregulation of IOP
Genome-wide association study identifies three novel genetic markers associated with elite endurance performance
To investigate the association between multiple single-nucleotide polymorphisms (SNPs), aerobic performance and elite endurance athlete status in Russians. By using GWAS approach, we examined the association between 1,140,419 SNPs and relative maximal oxygen consumption rate (VO 2 max) in 80 international-level Russian endurance athletes (46 males and 34 females). To validate obtained results, we further performed case-control studies by comparing the frequencies of the most significant SNPs (with P <10 -5 -10 -8 ) between 218 endurance athletes and opposite cohorts (192 Russian controls, 1367 European controls, and 230 Russian power athletes). Initially, six ‘endurance alleles’ were identified showing discrete associations with VO 2 max both in males and females. Next, case-control studies resulted in remaining three SNPs ( NFIA-AS2 rs1572312, TSHR rs7144481, RBFOX1 rs7191721) associated with endurance athlete status. The C allele of the most significant SNP, rs1572312, was associated with high values of VO 2 max (males: P =0.0051; females: P =0.0005). Furthermore, the frequency of the rs1572312 C allele was significantly higher in elite endurance athletes (95.5%) in comparison with non-elite endurance athletes (89.8%, P =0.0257), Russian (88.8%, P =0.007) and European (90.6%, P =0.0197) controls and power athletes (86.2%, P =0.0005). The rs1572312 SNP is located on the nuclear factor I A antisense RNA 2 ( NFIA-AS2 ) gene which is supposed to regulate the expression of the NFIA gene (encodes transcription factor involved in activation of erythropoiesis and repression of the granulopoiesis). Our data show that the NFIA-AS2 rs1572312, TSHR rs7144481 and RBFOX1 rs7191721 polymorphisms are associated with aerobic performance and elite endurance athlete status