EFFECT OF AIR VELOCITY ON INHALATION DOSES DUE TO RADON AND THORON PROGENY IN A TEST CHAMBER

2020 ◽  
Vol 189 (3) ◽  
pp. 401-405
Author(s):  
Rosaline Mishra ◽  
Rama Prajith ◽  
Rajeswari Pradhan Rout ◽  
Jalaluddin Sriamirullah ◽  
Balwinder Kaur Sapra
Keyword(s):  
Physical Properties ◽  
Environmental Conditions ◽  
Test Chamber ◽  
Air Velocity ◽  
Attachment Rate ◽  
Inhalation Dose ◽  
Decay Products ◽  
Calibration Chamber ◽  
Thoron Progeny

Abstract Inhalation doses due to radon and thoron are predominantly due to the inhalation of progeny of Radon and Thoron. The progeny/decay-products of radon and thoron are particulates unlike their parent gas and exhibit different physical properties like attachment to the aerosols and deposition on different surfaces. All these properties in turn depend on the environmental conditions such as air velocity, aerosol concentration, attachment rate, etc. The role of air velocity on deposition on surfaces decides the progeny particles left in the air for inhalation. Therefore, in the present work, we have studied the effect of air velocity on the inhalation dose due to radon and thoron progeny at the centre of a 0.5-m3 calibration chamber as well as on all surfaces. Hence, the studies were carried out at different air velocities, and inhalation doses were measured using deposition-based direct radon and thoron progeny sensors.

The role of rheological premonitory of hydrogels based on cellulose nanofibers and polymethylsilsesquioxane on the physical properties of corresponding aerogels

2021 ◽  
Vol 61 (4) ◽  
pp. 1220-1231
Author(s):  
Pragya Gupta ◽  
Akanksha Pandey ◽  
Kirtiraj K. Gaikwad ◽  
Sunanda Roy ◽  
Pradip K. Maji
Keyword(s):  
Physical Properties ◽  
Cellulose Nanofibers

Evaluating the role of soil physical properties on simulated land-atmosphere interactions over South Africa using coupled atmosphere-hydrological modeling

2021 ◽  
Author(s):  
Zhenyu Zhang ◽  
Patrick Laux ◽  
Joël Arnault ◽  
Jianhui Wei ◽  
Jussi Baade ◽  
...  
Keyword(s):  
South Africa ◽  
Physical Properties ◽  
Land Degradation ◽  
Land Surface ◽  
Soil Physical Properties ◽  
Near Surface ◽  
Soil Database ◽  
Global Soil ◽  
The Impact

<p>Land degradation with its direct impact on vegetation, surface soil layers and land surface albedo, has great relevance with the climate system. Assessing the climatic and ecological effects induced by land degradation requires a precise understanding of the interaction between the land surface and atmosphere. In coupled land-atmosphere modeling, the low boundary conditions impact the thermal and hydraulic exchanges at the land surface, therefore regulates the overlying atmosphere by land-atmosphere feedback processes. However, those land-atmosphere interactions are not convincingly represented in coupled land-atmosphere modeling applications. It is partly due to an approximate representation of hydrological processes in land surface modeling. Another source of uncertainties relates to the generalization of soil physical properties in the modeling system. This study focuses on the role of the prescribed physical properties of soil in high-resolution land surface-atmosphere simulations over South Africa. The model used here is the hydrologically-enhanced Weather Research and Forecasting (WRF-Hydro) model. Four commonly used global soil datasets obtained from UN Food and Agriculture Organization (FAO) soil database, Harmonized World Soil Database (HWSD), Global Soil Dataset for Earth System Model (GSDE), and SoilGrids dataset, are incorporated within the WRF-Hydro experiments for investigating the impact of soil information on land-atmosphere interactions. The simulation results of near-surface temperature, skin temperature, and surface energy fluxes are presented and compared to observational-based reference dataset. It is found that simulated soil moisture is largely influenced by soil texture features, which affects its feedback to the atmosphere.</p>

The role of diagenesis in the development of physical properties of deep-sea carbonate sediments

1985 ◽  
Vol 69 (1-2) ◽  
pp. 69-91 ◽  
Author(s):  
Dae-Choul Kim ◽  
Murli H Manghnani ◽  
Seymour O Schlanger
Keyword(s):  
Physical Properties ◽  
Deep Sea ◽  
Carbonate Sediments

scholarly journals Fisiología y ecología del fitocromo: su función en las semillas

2017 ◽  
pp. 71
Author(s):  
Alma Orozco-Segovia
Keyword(s):  
Environmental Conditions ◽  
Rain Forest ◽  
Los Tuxtlas ◽  
Developmental Processes ◽  
Plant Pigment ◽  
The Subject ◽  
Forest Plants

Phytochrome is the plant pigment which participate in several developmental processes regulated by light. In recent years this pigment has been associated with the detection of the environmental conditions but there is still a gap of information concerning the physioecological role of the pigment. In this paper the knowledge of the role of phytochrome on seed photoblastism is analysed based on several recent works done on the subject mainly with pioneer rain forest plants from Los Tuxtlas, Veracruz.

scholarly journals What is the role of sporadic phloem sap nitrate?

2021 ◽  
Author(s):  
Jing Cui ◽  
Andreas D. Peuke ◽  
Anis Limami ◽  
Guillaume Tcherkez
Keyword(s):  
Nutrient Cycling ◽  
Physical Properties ◽  
Plant Development ◽  
Nutrient Transport ◽  
Substantial Evidence ◽  
Phloem Sap ◽  
Essential Component

Since the first description of phloem sap composition nearly 60 years ago, it is generally assumed that phloem sap does not contain nitrate and that there is little or no backflow of nitrate from shoots to roots. While it is true that nitrate can occasionally be absent from phloem sap, there is now substantial evidence that phloem can carry nitrate and furthermore, transporters involved in nitrate redistribution to shoot sink organs and roots have been found. This raises the question of why nitrate may or may not be present in phloem sap, why its concentration is generally kept low, and whether plant shoot-root nutrient cycling also involves nitrate. We propose here that phloem sap nitrate is not only an essential component of plant nutritional signaling but also contributes to physical properties of phloem sap and as such, its concentration is controlled to ensure proper coordination of plant development and nutrient transport.

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