scholarly journals Application of Lidar Data to Assist Airmass Discrimination at the Whistler Mountaintop Observatory

2012 ◽  
Vol 51 (10) ◽  
pp. 1733-1739 ◽  
Author(s):  
John P. Gallagher ◽  
Ian G. McKendry ◽  
Paul W. Cottle ◽  
Anne Marie Macdonald ◽  
W. Richard Leaitch ◽  
...  
Keyword(s):  
Vapor Condensation ◽  
Lidar Data ◽  
Free Troposphere ◽  
Atmospheric Layer ◽  
Lidar System ◽  
Air Samples ◽  
Water Vapor Condensation ◽  
Air Chemistry ◽  
Ground Based Lidar ◽  
Time Series Images

AbstractA ground-based lidar system that has been deployed in Whistler, British Columbia, Canada, since the spring of 2010 provides a means of evaluating vertical aerosol structure in a mountainous environment. This information is used to help to determine when an air chemistry observatory atop Whistler Mountain (2182 m MSL) is within the free troposphere or is influenced by the valley-based planetary boundary layer (PBL). Three case studies are presented in which 1-day time series images of backscatter data from the lidar are analyzed along with concurrent meteorological and air-chemistry datasets from the mountaintop site. The cases were selected to illustrate different scenarios of diurnal PBL evolution that are expected to be common during their respective seasons. The lidar images corroborate assumptions about PBL influence as derived from analysis of diurnal trends in water vapor, condensation nuclei, and ozone. Use of all of these datasets together bolsters efforts to determine which atmospheric layer the site best represents, which is important when evaluating the provenance of air samples.

scholarly journals Viable SARS-CoV-2 in the air of a hospital room with COVID-19 patients

2020 ◽  
Author(s):  
John A Lednicky ◽  
Michael Lauzardo ◽  
Z. Hugh Fan ◽  
Antarpreet S Jutla ◽  
Trevor B Tilly ◽  
...  
Keyword(s):  
Cell Culture ◽  
Water Vapor ◽  
Respiratory Infection ◽  
Genome Sequence ◽  
Disease Transmission ◽  
Vapor Condensation ◽  
Active Infection ◽  
Air Samples ◽  
Water Vapor Condensation ◽  
Virus Culture

Background - There currently is substantial controversy about the role played by SARS-CoV-2 in aerosols in disease transmission, due in part to detections of viral RNA but failures to isolate viable virus from clinically generated aerosols. Methods - Air samples were collected in the room of two COVID-19 patients, one of whom had an active respiratory infection with a nasopharyngeal (NP) swab positive for SARS-CoV-2 by RT-qPCR. By using VIVAS air samplers that operate on a gentle water-vapor condensation principle, material was collected from room air and subjected to RT-qPCR and virus culture. The genomes of the SARS-CoV-2 collected from the air and of virus isolated in cell culture from air sampling and from a NP swab from a newly admitted patient in the room were sequenced. Findings - Viable virus was isolated from air samples collected 2 to 4.8m away from the patients. The genome sequence of the SARS-CoV-2 strain isolated from the material collected by the air samplers was identical to that isolated from the NP swab from the patient with an active infection. Estimates of viable viral concentrations ranged from 6 to 74 TCID50 units/L of air. Interpretation - Patients with respiratory manifestations of COVID-19 produce aerosols in the absence of aerosol-generating procedures that contain viable SARS-CoV-2, and these aerosols may serve as a source of transmission of the virus.

scholarly journals An Experimental Investigation of Water Vapor Condensation from Biofuel Flue Gas in a Model of Condenser, (1) Base Case: Local Heat Transfer without Water Injection

Processes ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 844
Author(s):  
Robertas Poškas ◽  
Arūnas Sirvydas ◽  
Vladislavas Kulkovas ◽  
Povilas Poškas
Keyword(s):  
Heat Transfer ◽  
Water Vapor ◽  
Flue Gas ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Water Injection ◽  
Vapor Condensation ◽  
Base Case ◽  
Water Vapor Condensation ◽  
Condensing Heat Exchanger

Waste heat recovery from flue gas based on water vapor condensation is an important issue as the waste heat recovery significantly increases the efficiency of the thermal power units. General principles for designing of this type of heat exchangers are known rather well; however, investigations of the local characteristics necessary for the optimization of those heat exchangers are very limited. Investigations of water vapor condensation from biofuel flue gas in the model of a vertical condensing heat exchanger were performed without and with water injection into a calorimetric tube. During the base-case investigations, no water was injected into the calorimetric tube. The results showed that the humidity and the temperature of inlet flue gas have a significant effect on the local and average heat transfer. For some regimes, the initial part of the condensing heat exchanger was not effective in terms of heat transfer because there the flue gas was cooled by convection until its temperature reached the dew point temperature. The results also showed that, at higher Reynolds numbers, there was an increase in the length of the convection prevailing region. After that region, a sudden increase was observed in heat transfer due to water vapor condensation.

Designing and building a novel, ground-based lidar system for aerosol typing in the Planetary Boundary Layer

2020 ◽  
Author(s):  
Rebecca Howe ◽  
Ioannis Binnietoglou ◽  
Jamie O.D. Williams ◽  
Alexandras Fragkos ◽  
George Tsaknakis ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Planetary Boundary Layer ◽  
Lidar System ◽  
Ground Based Lidar

Water vapor condensation on binary mixed substrates: A molecular dynamics study

2021 ◽  
pp. 122281
Author(s):  
Zi-Jie Wang ◽  
Shao-Yu Wang ◽  
Dan-Qi Wang ◽  
Yan-Ru Yang ◽  
Xiao-Dong Wang ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Water Vapor ◽  
Vapor Condensation ◽  
Mixed Substrates ◽  
Water Vapor Condensation

scholarly journals INFLUENCE OF LIGHTWEIGHT FILLERS ON THE PERFORMANCE OF CEMENT-BASED SKIM COAT

2020 ◽  
Vol 12 (1) ◽  
pp. 5-11
Author(s):  
MARCIN KUPIŃSKI ◽  
KAROLINA STOBIENIECKA ◽  
KAROL SKOWERA
Keyword(s):  
Thermal Conductivity ◽  
Thermal Conductivity Coefficient ◽  
Pozzolanic Reaction ◽  
Vapor Condensation ◽  
Cement Matrix ◽  
Capillary Absorption ◽  
Mold Growth ◽  
Expanded Perlite ◽  
Water Vapor Condensation ◽  
Effective Additive

Lightweight fillers are used in dry-mixed building mortars in order to improve thermal insulation properties, yield, and workability. In the case of thin layer products, used as a finishing layer, reduced thermal conductivity coefficient enables to restrain of water vapor condensation on walls – which inhibits mold growth. The aim of the study was to determine the influence of 4 types of lightweight fillers on the performance of cement-based skim coat – with emphasis on the economic aspect. Formulas reflecting typical commercial products were used. The dosage of different components -such as expanded perlite, glass and polymeric bubbles or expanded glass – was optimized for sufficient yield and workability, keeping the constant price of 1 kg of the final product. Mechanical parameters, capillary absorption coefficient, and thermal conductivity coefficient were determined. Observations by Scanning Electron Microscope revealed poor incorporation of polymer microspheres in the cement matrix, leading to loss of mechanical strength. With the addition of expanded glass, an increase of flexural and compressive strength thanks to the pozzolanic reaction was observed. Glass bubbles were found the most effective additive.

scholarly journals A Model Study of Building Seismic Damage Information Extraction and Analysis on Ground-Based LiDAR Data

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Fan Yang ◽  
Xintao Wen ◽  
Xiaoshan Wang ◽  
Xiaoli Li ◽  
Zhiqiang Li
Keyword(s):  
High Precision ◽  
Laser Scanning ◽  
Full Range ◽  
Scientific Basis ◽  
Building Damage ◽  
Vector Model ◽  
Lidar Data ◽  
Emergency Relief ◽  
Cloud Data ◽  
Ground Based Lidar

Earthquake disasters can have a serious impact on people’s lives and property, with damage to buildings being one of the main causes of death and injury. A rapid assessment of the extent of building damage is essential for emergency response management, rescue operations, and reconstruction. Terrestrial laser scanning technology can obtain high precision light detection and ranging (LiDAR) point cloud data of the target. The technology is widely used in various fields; however, the quantitative analysis of building seismic information is the focus and difficulty of ground-based LiDAR data analysis processing. This paper takes full advantage of the high-precision characteristics of ground-based LiDAR data. A triangular network vector model (TIN-shaped model) was created in conjunction with the alpha shapes algorithm, solving the problem of small, nonvisually identifiable postearthquake building damage feature extraction bias. The model measures the length, width, and depth of building cracks, extracts the amount of wall tilt deformation, and labels the deformation zone. The creation of this model can provide scientific basis and technical support for postearthquake emergency relief, assessment of damage to buildings, extraction of deformation characteristics of other structures (bridges, tunnels, dams, etc.), and seismic reinforcement of buildings. The research data in this paper were collected by the author’s research team in the first time after the 2013 Lushan earthquake and is one of the few sets of foundation of LiDAR data covering the full range of postearthquake building types in the region, with the data information mainly including different damage levels of different structural types of buildings. The modeling analysis of this data provides a scientific basis for establishing the earthquake damage matrix of buildings in the region.

Gasdynamic water-vapor-condensation laser

1975 ◽  
Vol 5 (9) ◽  
pp. 1131-1132
Author(s):  
V K Konyukhov ◽  
A M Prokhorov ◽  
V I Tikhonov ◽  
V N Faizulaev
Keyword(s):  
Water Vapor ◽  
Vapor Condensation ◽  
Water Vapor Condensation
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