scholarly journals Quantifying the Role of the Relative Humidity-Dependent Physical State of Organic Particulate Matter in the Uptake of Semivolatile Organic Molecules

2019 ◽  
Vol 53 (22) ◽  
pp. 13209-13218
Author(s):  
Yuemei Han ◽  
Zhaoheng Gong ◽  
Jianhuai Ye ◽  
Pengfei Liu ◽  
Karena A. McKinney ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Relative Humidity ◽  
Physical State ◽  
Organic Molecules ◽  
Organic Particulate Matter

scholarly journals Relative humidity-dependent viscosity of secondary organic material from toluene photo-oxidation and possible implications for organic particulate matter over megacities

2016 ◽  
Author(s):  
M. Song ◽  
P. F. Liu ◽  
S. J. Hanna ◽  
R. A. Zaveri ◽  
K. Potter ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Relative Humidity ◽  
Diffusion Coefficients ◽  
Organic Material ◽  
Organic Molecules ◽  
Mixing Times ◽  
Organic Particulate Matter ◽  
Photo Oxidation ◽  
Diffusion Rates ◽  
And Diffusion

Abstract. To improve predictions of air quality, visibility, and climate change, knowledge of the viscosities and diffusion rates within organic particulate matter consisting of secondary organic material (SOM) is required.Most qualitative and quantitative measurements of viscosity and diffusion rates within organic particulate matter have focused on SOM particles generated from biogenic VOCs such as α-pinene and isoprene. In this study, we quantify the relative humidity (RH)-dependent viscosities at 295 ± 1 K of SOM produced by photo-oxidation of toluene, an anthropogenic VOC. The viscosities of toluene-derived SOM were 2 × 10−1 to ∼6 × 106 Pa·s from 30 to 90 % RH, and greater than ~2 × 108 Pa·s (similar to or greater than the viscosity of tar pitch) for RH ≤ 17 %. These viscosities correspond to Stokes-Einstein-equivalent diffusion coefficients for large organic molecules of ~2 × 10−15 cm2·s−1 for 30 % RH, and lower than ~3 × 10−17 cm2·s−1 for RH ≤ 17 %. Based on these estimated diffusion coefficients, the mixing time of large organic molecules within 200 nm toluene-derived SOM particles is 0.1–5 hr for 30 % RH, and higher than ~100 hr for RH ≤ 17 %. These results were used, as a first-order approximation, to estimate if organic particulate matter will be in well-mixed over the world's top 15 most populous megacities. If the organic particulate matter in the megacities is similar to the toluene-derived SOM in this study, in Kolkata, Istanbul, Dhaka, Tokyo, Shanghai, and Mumbai, mixing times in organic particulate matter during extended periods of the year will be very short, and well-mixed particles can be assumed. On the other hand, the mixing times of large organic molecules in organic particulate matter in Delhi, Beijing, Mexico City, Cairo, and Karachi may be long and the particles may not be well-mixed in the afternoon (3:00–5:00 local time) during certain times of the year.

scholarly journals Relative humidity-dependent viscosity of secondary organic material from toluene photo-oxidation and possible implications for organic particulate matter over megacities

2016 ◽  
Vol 16 (14) ◽  
pp. 8817-8830 ◽  
Author(s):  
Mijung Song ◽  
Pengfei F. Liu ◽  
Sarah J. Hanna ◽  
Rahul A. Zaveri ◽  
Katie Potter ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Relative Humidity ◽  
Diffusion Coefficients ◽  
Organic Material ◽  
Organic Molecules ◽  
Mixing Times ◽  
Organic Particulate Matter ◽  
Photo Oxidation ◽  
Diffusion Rates ◽  
And Diffusion

Abstract. To improve predictions of air quality, visibility, and climate change, knowledge of the viscosities and diffusion rates within organic particulate matter consisting of secondary organic material (SOM) is required. Most qualitative and quantitative measurements of viscosity and diffusion rates within organic particulate matter have focused on SOM particles generated from biogenic volatile organic compounds (VOCs) such as α-pinene and isoprene. In this study, we quantify the relative humidity (RH)-dependent viscosities at 295 ± 1 K of SOM produced by photo-oxidation of toluene, an anthropogenic VOC. The viscosities of toluene-derived SOM were 2  ×  10−1 to  ∼  6  ×  106 Pa s from 30 to 90 % RH, and greater than  ∼  2  ×  108 Pa s (similar to or greater than the viscosity of tar pitch) for RH  ≤  17 %. These viscosities correspond to Stokes–Einstein-equivalent diffusion coefficients for large organic molecules of  ∼  2  ×  10−15 cm2 s−1 for 30 % RH, and lower than  ∼  3  ×  10−17 cm2 s−1 for RH  ≤  17 %. Based on these estimated diffusion coefficients, the mixing time of large organic molecules within 200 nm toluene-derived SOM particles is 0.1–5 h for 30 % RH, and higher than  ∼  100 h for RH  ≤  17 %. As a starting point for understanding the mixing times of large organic molecules in organic particulate matter over cities, we applied the mixing times determined for toluene-derived SOM particles to the world's top 15 most populous megacities. If the organic particulate matter in these megacities is similar to the toluene-derived SOM in this study, in Istanbul, Tokyo, Shanghai, and São Paulo, mixing times in organic particulate matter during certain periods of the year may be very short, and the particles may be well-mixed. On the other hand, the mixing times of large organic molecules in organic particulate matter in Beijing, Mexico City, Cairo, and Karachi may be long and the particles may not be well-mixed in the afternoon (15:00–17:00 LT) during certain times of the year.

The enzymology of sludge solubilisation utilising sulphate reducing systems: the role of lipases

2003 ◽  
Vol 48 (8) ◽  
pp. 159-167
Author(s):  
C.G. Whiteley ◽  
X. Melamane ◽  
B. Pletschke ◽  
P.D. Rose
Keyword(s):  
Particulate Matter ◽  
Reduction Process ◽  
Organic Particulate Matter ◽  
Lipase Enzyme ◽  
Carbon Structures ◽  
Time Period ◽  
Hydrolysis Of ◽  
Acidic Components ◽  
Sulphur Species

The first stage in the degradation and recycling of particulate organic matter is the solubilisation and enhanced hydrolysis of complex polymeric organic carbon structures associated with the sulphidogenic environment. An investigation into the enzymology of these processes has shown that lipase enzyme activities were found predominantly associated with the organic particulate matter of the sewage sludge. Sonication of the sludge gave an increase in enzyme activity as the enzymes were released into the supernatant. pH and temperature optimisation studies showed optima at between 6.5 and 8 and 50-60°C, respectively. All the lipase enzymes from the methanogenic bioreactors indicated extensive stability for at least an hour at their respective optimum temperatures and pH; sulphidogenic lipases reflected limited stability at these temperatures and pH during this time period. Though sulphate showed inhibitory properties towards lipases both sulphide and sulphite appeared to enhance the activity of the enzymes. It is argued that these sulphur species, liberated at different times during the sulphate reduction process, disrupt the integrity of the organic particulate floc by neutralising acidic components on the surface. The release of further entrapped enzymes from the organic particulate matter results in a subsequent enhancement of hydrolysis of polymeric material.

The Role of the Organic Particulate Matter in the Distribution of Trace Metals in Sea Water

1986 ◽  
Vol 2 (4) ◽  
pp. 313-317
Author(s):  
F. Baffi ◽  
M. Fabiano ◽  
A. Dadone ◽  
R. Frache
Keyword(s):  
Particulate Matter ◽  
Trace Metals ◽  
Sea Water ◽  
Organic Particulate Matter

Disseminated intravascular coagulation syndrome

2020 ◽  
pp. 22-40
Author(s):  
A. Kulikov
Keyword(s):  
Clinical Practice ◽  
Disseminated Intravascular Coagulation ◽  
Blood Cells ◽  
Physical State ◽  
Clinical Manifestations ◽  
Vascular Wall ◽  
Stages Of Development ◽  
Intravascular Coagulation ◽  
Hemostatic Disorder

Presented material reveals main links in the pathogenesis of hemostatic disorder. In particular, attention is paid to the role of the lungs, liver and other organs in the development of this process. Role of vascular wall and blood cells in regulation of the physical state of blood is described in detail. The most frequent factors leading to hypercoagulation are indicated. Difference between hypercoagulation and thrombophilia is shown. The latter is found in clinical practice quite often, but at the same time, it is poorly diagnosed. Such a terrible complication of hemostatic disorder as disseminated intravascular coagulation is described. Its classification, stages of development, clinical manifestations are offered to the readers.

The Role of Ecopedological Parameters in Management Sustainability of Banat Lands

2018 ◽  
Vol 69 (3) ◽  
pp. 688-692
Author(s):  
Lucian Nita ◽  
Dorin Tarau ◽  
Gheorghe Rogobete ◽  
Simona Nita ◽  
Radu Bertici ◽  
...  
Keyword(s):  
Plant Nutrition ◽  
Physical State ◽  
Agricultural Land ◽  
Soil Characteristics ◽  
South West ◽  
Short And Long Term ◽  
Laboratory Investigations ◽  
Case Basis

The issue addressed relates to an area of 1891694 ha of which 1183343 ha are agricultural land (62, 56) located in the south-west of Romania and refer to the use of soil chemical and physical properties as an acceptor for certain crop systems, with minimal undesirable effects both for plants to be grown, as well as soil characteristics and groundwater surface quality. It is therefore necessary on a case-by-case basis, measure stoc or rect the acidic reaction by periodic or alkaline calculations, the improvement of plant nutrition conditions through ameliorative fertilization and the application of measures to improve the physical state, sufficient justification for the need to develop short and long term strategies for the protection and conservation of edifying factors and the need to respect the frequency of field and laboratory investigations at all 8x8 km grids of the National Soil-Grounds Monitoring System (organized by I.C.P.A.) and completing it with the relevant pedological and agrochemical studies.

scholarly journals Did Cyclic Metaphosphates Have a Role in the Origin of Life?

2021 ◽  
Author(s):  
Thomas Glonek
Keyword(s):  
Organic Molecules ◽  
Water Soluble ◽  
Holliday Junction ◽  
Additional Energy ◽  
Condensed Phosphate ◽  
Geological Processes ◽  
The Origin Of Life ◽  
Complex Forms ◽  
Self Replication

AbstractHow life began still eludes science life, the initial progenote in the context presented herein, being a chemical aggregate of primordial inorganic and organic molecules capable of self-replication and evolution into ever increasingly complex forms and functions.Presented is a hypothesis that a mineral scaffold generated by geological processes and containing polymerized phosphate units was present in primordial seas that provided the initiating factor responsible for the sequestration and organization of primordial life’s constituents. Unlike previous hypotheses proposing phosphates as the essential initiating factor, the key phosphate described here is not a polynucleotide or just any condensed phosphate but a large (in the range of at least 1 kilo-phosphate subunits), water soluble, cyclic metaphosphate, which is a closed loop chain of polymerized inorganic phosphate residues containing only phosphate middle groups. The chain forms an intrinsic 4-phosphate helix analogous to its structure in Na Kurrol’s salt, and as with DNA, very large metaphosphates may fold into hairpin structures. Using a Holliday-junction-like scrambling mechanism, also analogous to DNA, rings may be manipulated (increased, decreased, exchanged) easily with little to no need for additional energy, the reaction being essentially an isomerization.A literature review is presented describing findings that support the above hypothesis. Reviewed is condensed phosphate inorganic chemistry including its geological origins, biological occurrence, enzymes and their genetics through eukaryotes, polyphosphate functions, circular polynucleotides and the role of the Holliday junction, previous biogenesis hypotheses, and an Eoarchean Era timeline.

scholarly journals Prioritizing and Analyzing the Role of Climate and Urban Parameters in the Confirmed Cases of COVID-19 Based on Artificial Intelligence Applications

2020 ◽  
Vol 17 (10) ◽  
pp. 3730 ◽  
Author(s):  
Sina Shaffiee Haghshenas ◽  
Behrouz Pirouz ◽  
Sami Shaffiee Haghshenas ◽  
Behzad Pirouz ◽  
Patrizia Piro ◽  
...  
Keyword(s):  
Artificial Intelligence ◽  
Infectious Disease ◽  
Relative Humidity ◽  
Cost Function ◽  
Selection Process ◽  
Environmental Parameters ◽  
Pso Algorithm ◽  
Data Set ◽  
De Algorithm

Nowadays, an infectious disease outbreak is considered one of the most destructive effects in the sustainable development process. The outbreak of new coronavirus (COVID-19) as an infectious disease showed that it has undesirable social, environmental, and economic impacts, and leads to serious challenges and threats. Additionally, investigating the prioritization parameters is of vital importance to reducing the negative impacts of this global crisis. Hence, the main aim of this study is to prioritize and analyze the role of certain environmental parameters. For this purpose, four cities in Italy were selected as a case study and some notable climate parameters—such as daily average temperature, relative humidity, wind speed—and an urban parameter, population density, were considered as input data set, with confirmed cases of COVID-19 being the output dataset. In this paper, two artificial intelligence techniques, including an artificial neural network (ANN) based on particle swarm optimization (PSO) algorithm and differential evolution (DE) algorithm, were used for prioritizing climate and urban parameters. The analysis is based on the feature selection process and then the obtained results from the proposed models compared to select the best one. Finally, the difference in cost function was about 0.0001 between the performances of the two models, hence, the two methods were not different in cost function, however, ANN-PSO was found to be better, because it reached to the desired precision level in lesser iterations than ANN-DE. In addition, the priority of two variables, urban parameter, and relative humidity, were the highest to predict the confirmed cases of COVID-19.

scholarly journals Role of nanostructured polymers on the improvement of electrical response-based relative humidity sensors

2016 ◽  
Vol 225 ◽  
pp. 96-108 ◽  
Author(s):  
I. Fratoddi ◽  
A. Bearzotti ◽  
I. Venditti ◽  
C. Cametti ◽  
M.V. Russo
Keyword(s):  
Relative Humidity ◽  
Electrical Response ◽  
Nanostructured Polymers ◽  
Humidity Sensors
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