Limited assessment of a selected particulate matter sensor technology in emission measurement applications on diesel vehicles

The study assessed the ability of a novel particle sensor to provide adequate evaluation of real-time emissions from modem diesel engines and estimate the effectiveness of emission control devices. Emission data were obtained from vehicles in real-world field conditions under various test cycles. The datasets were used to determine whether there is an association between particulate matter (PM) measurements produced by particle sensor and the PM measurements from reference instrument. Exploratory analysis was combined with statistical techniques to investigate suitability of particle sensor to adequately measure PM mass concentrations in exhaust gases of modem diesel vehicles. Results of the study identified strong positive association between measurements from particle sensor and reference instrument. Study confirmed the suitability of the sensor in the field to measure PM emissions of diesel vehicles. These findings are useful to researchers and governmental agencies involved in regulation, control, and monitoring of diesel engine emissions

The development of urban agglomeration in a pandemic

The features of the modern development of urban agglomerations should be considered from the standpoint of the changed conditions of the socio-ecological space. They are associated with the situation of a pandemic, which is especially aggravated in large cities. Since Kazan is a developing city, the possibilities of creating new conditions on the territory of expansion were considered. Two aspects of design are considered, which are associated with the study of the clinical manifestations of viral diseases and the formation of resilience in the organization of the environment for elderly people. The study highlights the main features of design approaches for centers studying human immunology and residential clusters that take into account the characteristics of the elderly. In the context of the territory, design principles were proposed, considered as infrastructure principles and residential cluster principles. The infrastructure associated with human learning is expressed in the following: isolation, planning cyclicality, polyfunctionality, accessibility for the elderly. Residential development is based on: spatial identity, human scale of the environment, continuity of communications, inclusion in the natural environment. Thus, it seems possible to work out a unique solution in terms of sustainable development of previously abandoned territories. Attentive attitude to landscape components is on a par with a humanistic attitude towards the most vulnerable groups of the population

Modification of cell wall polysaccharide guides cell division in <i>Streptococcus mutans</i>

In ovoid-shaped, Gram-positive bacteria, MapZ guides FtsZ-ring positioning at cell equators. The cell wall of the ovococcus Streptococcus mutans contains peptidoglycan decorated with serotype c carbohydrates (SCCs). In the present study, we identify the major cell separation autolysin AtlA as an SCC-binding protein. AtlA binding to SCC is attenuated by the glycerol phosphate (GroP) modification. Using fluorescently labeled AtlA constructs, we mapped SCC distribution on the streptococcal surface, revealing enrichment of GroP-deficient immature SCCs at the cell poles and equators. The immature SCCs co-localize with MapZ at the equatorial rings throughout the cell cycle. In GroP-deficient mutants, AtlA is mislocalized, resulting in dysregulated cellular autolysis. These mutants display morphological abnormalities associated with MapZ mislocalization, leading to FtsZ-ring misplacement. Altogether, our data support a model in which maturation of a cell wall polysaccharide provides the molecular cues for the recruitment of cell division machinery, ensuring proper daughter cell separation and FtsZ-ring positioning. [Figure not available: see fulltext.

PplD Is a De-N-Acetylase of the Cell Wall Linkage Unit of Streptococcal Rhamnopolysaccharides

The cell wall of the human bacterial pathogen Group A Streptococcus (GAS) consists of peptidoglycan decorated with the Lancefield group A carbohydrate (GAC). GAC is a promising target for the development of GAS vaccines. In this study, employing chemical, compositional, and NMR methods, we show that GAC is attached to peptidoglycan via glucosamine 1-phosphate. This structural feature makes the GAC-peptidoglycan linkage highly sensitive to cleavage by nitrous acid and resistant to mild acid conditions. Using this characteristic of the GAS cell wall, we identify PplD as a protein required for deacetylation of linkage N-acetylglucosamine (GlcNAc). X-ray structural analysis indicates that PplD performs catalysis via a modified acid/base mechanism. Genetic surveys in silico together with functional analysis indicate that PplD homologs deacetylate the polysaccharide linkage in many streptococcal species. We further demonstrate that introduction of positive charges to the cell wall by GlcNAc deacetylation protects GAS against host cationic antimicrobial proteins

ORIENTAL JOURNAL OF CHEMISTRY Quantitative Chemical Analysis of Slag Ash of Novocherkassk State District Power Plant

AbSTRACT Quantitative chemical composition of ash and slag mix generated upon combustion of Donetsk culm is determined. It is established that ash and slag mix of Novocherkassk state district power plant (SDPP) (Rostov region, Russia) after coal combustion has the following composition: iron -2.3%; mineral constituents -75.8%; calcium oxide -20.4%; aluminum oxide -0.0118%; water -1.3022%; manganese oxide -0.18%; copper oxide -0.0043%; plumbum -0.0017%; it is qualified as hazard class IV for environment. Cadmium, mercury, arsenic, selenium, antimony, bismuth are contained in trace amounts &lt; 0.1 mg/kg. In order to reduce dust emissions the cleaning stage I of gas scrubbing facility is equipped with group cyclone comprised of four cyclone units. Medium and coarse particles under the action of centrifugal force are deposited in the cyclone. This promoted decrease in dust load on bag filters, the cleaning stage II. Qualitative chemical composition of ash captured by group cyclone and that of ash captured by bag filter are determined. Cadmium, copper, plumbum, zinc, iron, manganese, and calcium are contained in coarse and fine particles captured by group cyclone and bag filter. Aluminum referred to light metals is completely captured by cyclone. The ash dust in its bulk is of dark gray color. The ash captured by cyclone contains coarse particles of black color and the ash captured bag filter contains fine particles of light colors (gray-yellow color producing silky gloss). This is characteristic for ash dust after combustion of Donetsk culm. The main component of the ash is silicon dioxide, its content in the ash captured by filter reaches 91%. These fine particles create light tone of this ash

Probability density function of fluctuating intensity of a laser beam propagating in marine atmospheric turbulence

We report on the analysis of experimental data collected at the United States Naval Academy in the Summer and Fall of 2010. A low-power red He-Ne laser source was used to generate a Gaussian beam. The beam was directed horizontally above the ground and over the water for 400 m during daytime. The transverse cross-section of the beam was projected on a white screen and imaged using a ccd camera. The histogram of the fluctuating intensity at the center of the beam was obtained from the sequence of photographs. Comparison was made of the histogram and probability density functions of fluctuating intensity based on two existing analytic models, Gamma-Gamma and Gamma-Laguerre. Also the comparison of the beam statistics above the ground and over the water was performed

Probability density function of fluctuating intensity of a laser beam propagating in marine atmospheric turbulence

We report on the analysis of experimental data collected at the United States Naval Academy in the Summer and Fall of 2010. A low-power red He-Ne laser source was used to generate a Gaussian beam. The beam was directed horizontally above the ground and over the water for 400 m during daytime. The transverse cross-section of the beam was projected on a white screen and imaged using a ccd camera. The histogram of the fluctuating intensity at the center of the beam was obtained from the sequence of photographs. Comparison was made of the histogram and probability density functions of fluctuating intensity based on two existing analytic models, Gamma-Gamma and Gamma-Laguerre. Also the comparison of the beam statistics above the ground and over the water was performed

Probability density function of partially coherent beams propagating in the atmospheric turbulence

Measurements of the intensity of a light beam produced by a laser source, reflected from a Spatial Light Modulator (SLM) and propagating in a weakly turbulent maritime atmosphere have been carried out in a recent campaign on the grounds of the US Naval Academy. The effect of the degree of spatial coherence in the beam at the source plane (right after the reflection from the SLM) on the Probability Density Function (PDF) of the intensity of the propagating beam at a single fixed position in space is studied in detail. The measured intensity histogram of the fluctuating intensity is compared with the Gamma-Laguerre analytical model for the intensity PDF

Probability density function of the intensity of a laser beam propagating in the maritime environment

A number of field experiments measuring the fluctuating intensity of a laser beam propagating along horizontal paths in the maritime environment is performed over sub-kilometer distances at the United States Naval Academy. Both above the ground and over the water links are explored. Two different detection schemes, one photographing the beam on a white board, and the other capturing the beam directly using a ccd sensor, gave consistent results. The probability density function (pdf) of the fluctuating intensity is reconstructed with the help of two theoretical models: the Gamma-Gamma and the Gamma-Laguerre, and compared with the intensity's histograms. It is found that the on-ground experimental results are in good agreement with theoretical predictions. The results obtained above the water paths lead to appreciable discrepancies, especially in the case of the Gamma-Gamma model. These discrepancies are attributed to the presence of the various scatterers along the path of the beam, such as water droplets, aerosols and other airborne particles. Our paper's main contribution is providing a methodology for computing the pdf function of the laser beam intensity in the maritime environment using field measurements

Studying the Efficiency of Treatment Model Mixtures of Petroleum Products with the Modified Sorbent Made of Ash-and-Slag During Dynamic Sorption

Experimental studies on the dynamic sorption of model mixtures containing petroleum products were performed. The subject of the study was the modified sorbent from the ash-and-slag wastes accumulated in the ash dump of the Novocherkassk State District Power Plant (SDPP) (Russia, Novocherkassk, Rostov Region), obtained using the method of ash removal. The quantity of the sorbent for each model solution was fixed at 5.0 g. The model solutions in the amount of 1 dm3 were passed through a column filled with the modified sorbent at constant filtration rate w = const with filtrate takeout of 0.1 dm3/min. The pH value of the solution, which is advisable for extracting petroleum products, was determined experimentally. For this purpose, the model solutions, containing 100 mg/dm3 of petroleum products with pH = 1.65, 4.01, 6.86, 8.12, 9.18, and 11.34, were prepared. The optimum pH value of the solution was considered pH = 7.5. The content of petroleum products in the filtrate in all experiments was determined using IR spectrometry. The working range of water pollution with petroleum products was determined on a series of model solutions containing petroleum products in the range between 0.5 and 10 mg/dm3 with the increment of 0.5, between 10 and 100 mg/dm3 with the increment of 10, and between 100 and 1,000 mg/dm3 with the increment of 100. The maximum extraction of petroleum products from the solution was 88.23%. The applicability of the Henry’s law to the range of petroleum products concentrations in the filtrate of 50 mg/dm3 was confirmed. The adsorption equilibrium constant (Henry’s law constant) was determined experimentally. The effect of the natural freshwater matrix on the degree of petroleum products extraction was studied; no significant effect on petroleum products sorption was found. A conclusion was made that the sorbent can ensure the efficiency of water purifying from petroleum products of no less than 85% in the range of pollution between 5 and 300 mg/dm3