Polarization Lidar at Summit, Greenland, for the Detection of Cloud Phase and Particle Orientation

2013 ◽  
Vol 30 (8) ◽  
pp. 1635-1655 ◽  
Author(s):  
Ryan R. Neely ◽  
Matthew Hayman ◽  
Robert Stillwell ◽  
Jeffrey P. Thayer ◽  
R. Michael Hardesty ◽  
...  
Keyword(s):  
Full Range ◽  
Particle Orientation ◽  
Earth System ◽  
System Research ◽  
Cloud Properties ◽  
Atmospheric State ◽  
Initial Results

Abstract Accurate measurements of cloud properties are necessary to document the full range of cloud conditions and characteristics. The Cloud, Aerosol Polarization and Backscatter Lidar (CAPABL) has been developed to address this need by measuring depolarization, particle orientation, and the backscatter of clouds and aerosols. The lidar is located at Summit, Greenland (72.6°N, 38.5°W; 3200 m MSL), as part of the Integrated Characterization of Energy, Clouds, Atmospheric State, and Precipitation at Summit Project and NOAA's Earth System Research Laboratory's Global Monitoring Division's lidar network. Here, the instrument is described with particular emphasis placed upon the implementation of new polarization methods developed to measure particle orientation and improve the overall accuracy of lidar depolarization measurements. Initial results from the lidar are also shown to demonstrate the ability of the lidar to observe cloud properties.

scholarly journals Comparison of ISS–CATS and CALIPSO–CALIOP Characterization of High Clouds in the Tropics

2020 ◽  
Vol 12 (23) ◽  
pp. 3946
Author(s):  
Pasquale Sellitto ◽  
Silvia Bucci ◽  
Bernard Legras
Keyword(s):  
Optical Properties ◽  
Space Station ◽  
Satellite Observation ◽  
Observation Data ◽  
Upper Troposphere ◽  
Cloud Properties ◽  
Synchronous Orbit ◽  
The Tropics ◽  
High Clouds

Clouds in the tropics have an important role in the energy budget, atmospheric circulation, humidity, and composition of the tropical-to-global upper-troposphere–lower-stratosphere. Due to its non-sun-synchronous orbit, the Cloud–Aerosol Transport System (CATS) onboard the International Space Station (ISS) provided novel information on clouds from space in terms of overpass time in the period of 2015–2017. In this paper, we provide a seasonally resolved comparison of CATS characterization of high clouds (between 13 and 18 km altitude) in the tropics with well-established CALIPSO (Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observation) data, both in terms of clouds’ occurrence and cloud optical properties (optical depth). Despite the fact that cloud statistics for CATS and CALIOP are generated using intrinsically different local overpass times, the characterization of high clouds occurrence and optical properties in the tropics with the two instruments is very similar. Observations from CATS underestimate clouds occurrence (up to 80%, at 18 km) and overestimate the occurrence of very thick clouds (up to 100% for optically very thick clouds, at 18 km) at higher altitudes. Thus, the description of stratospheric overshoots with CATS and CALIOP might be different. While this study hints at the consistency of CATS and CALIOP clouds characterizaton, the small differences highlighted in this work should be taken into account when using CATS for estimating cloud properties and their variability in the tropics.

scholarly journals Characterization of proteoglycan and the proteoglycan-hyaluronic acid complex by electric birefringence

1978 ◽  
Vol 173 (1) ◽  
pp. 237-243 ◽  
Author(s):  
M Isles ◽  
A R Foweraker ◽  
B R Jennings ◽  
T Hardingham ◽  
H Muir
Keyword(s):  
Hyaluronic Acid ◽  
Particle Orientation ◽  
Dilute Solution ◽  
Relaxation Rates ◽  
Acid Complex ◽  
Electric Birefringence ◽  
Partial Alignment ◽  
Uronic Acid Content ◽  
Birefringence Relaxation

An electric field causes partial alignment of macromolecules in a dilute solution. The accompanying changes in the solution birefringence offer a sensitive and quick means of monitoring the rates of particle orientation and hence the size of the solute molecules. Such measurements are reported for dilute solutions of proteoglycans in the absence and presence of added hyaluronic acid. The proteoglycan molecules are shown to be some 580 nm long. In the presence of hyaluronic acid they form aggregates that appear to be consistent with the model previously proposed in which the proteoglycans attach radially to the extended hyaluronic acid chain. The electric-birefringence relaxation rates indicate aggregates of similar length to that of the extended hyaluronic acid chain, with the proteoglycans spaced on average at 29nm intervals. A proteoglycan sample the cystine residues of which had been reduced and alkylated showed no evidence of aggregation with hyaluronic acid up to the concentrations of the acid corresponding to 1% of the total uronic acid content. The electric-birefringence method is shown to have a large potential in the study of associating polysaccharide solutions.

A- and B-site doping effect on physicochemical properties of Sr2−xBaxMMoO6 (M = Mg, Mn, Fe) double perovskites — candidate anode materials for SOFCs

2016 ◽  
Vol 09 (04) ◽  
pp. 1641002 ◽  
Author(s):  
Kun Zheng ◽  
Konrad Świerczek
Keyword(s):  
Physicochemical Properties ◽  
Solid Oxide Fuel Cells ◽  
Anode Materials ◽  
Full Range ◽  
Solid Oxide ◽  
Double Perovskites ◽  
Reducing Conditions ◽  
Redox Stability ◽  
Very High

In this work, we evaluate the physicochemical properties of Sr[Formula: see text]BaxMMoO6 (M [Formula: see text] Mg, Mn, Fe) double perovskites as alternative anode materials for solid oxide fuel cells, for which the effect of substitution of strontium by barium in a full range of compositions is studied. The crystal structure, microstructure, characterization of transport properties (electrical conductivity, Seebeck coefficient) and oxygen content as a function of temperature, as well as chemical stability in oxidizing and reducing conditions are discussed. Fe- and Mo-containing Sr[Formula: see text]BaxFeMoO6 oxides show very high total conductivities with values of 100–1000 S[Formula: see text][Formula: see text]cm[Formula: see text], while Sr[Formula: see text]BaxMgMoO6 present good redox stability.

scholarly journals Estudo da Temperatura da Superfície do Mar para os Oceanos Atlântico e Pacífico Utilizando a Técnica de Análises de Componente Principal e de Agrupamento (Study of Sea Surface Temperature for the Atlantic and Pacific Oceans Using the Technique of...)

2011 ◽  
Vol 4 (2) ◽  
pp. 264
Author(s):  
Madson Tavares Silva ◽  
Stephany C. F. Do Egito Costa ◽  
Manoel Francisco Gomes Filho ◽  
Daisy B. Lucena
Keyword(s):  
Principal Component Analysis ◽  
Cluster Analysis ◽  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Research Laboratory ◽  
Principal Component ◽  
Component Analysis ◽  
Sea Surface ◽  
Earth System ◽  
System Research

Apresenta-se neste estudo a avaliação da metodologia de Análises Multivariadas: Análises em Componente Principal (ACP) e de Agrupamento (AA), aos dados de Temperatura da Superfície do Mar (TSM) para os Oceanos Atlântico (Norte (NATL), Tropical (TROP) e Sul (SATL)) e Pacifico (NIÑO1+2, NIÑO3.4, NIÑO3 e NIÑO4). Foram utilizados dados mensais de janeiro de 1950 a dezembro de 2010 de TSM obtidos na NOAA (National Oceanic and Atmospheric Administration/Earth System Research Laboratory). As regiões TROP e NIÑO4 apresentam as maiores TSM para os meses entre dezembro-julho. A região NATL apresenta no período de agosto-outubro seu maiores valores de TSM. A região NIÑo1+2 apresentou os menores valores de TSM. Os resultados da Análise em Componente Principal (ACP) identificaram maiores pesos na variação total explicada pelas duas primeiras componentes, que representam cerca de 100% da variância total dos dados de TSM. A Análise de Agrupamento (AA), pelo método Ward, permitiu o agrupamento das estações em três grupos homogêneos. Palavras - chave: Análises Multivariadas, Mudanças climáticas, Aquecimento Global.   Study of Sea Surface Temperature for the Atlantic and Pacific Oceans Using the Technique of Principal Component Analysis and Cluster   ABSTRACT Presented in this study was to evaluate the methodology of Multivariate Analysis: Principal Component Analysis (PCA) and cluster analysis (CA), the data of sea surface temperature (SST) for the Atlantic (North (NATL), Tropical (TROP) and South (Satler)) and Pacific (+2 NIÑO1, NIÑO3.4, and NIÑO3 NIÑO4). We used monthly data from January 1950 to December 2010 SST obtained from NOAA (National Oceanic and Atmospheric Administration / Earth System Research Laboratory). TROP and NIÑO4 regions have the highest SST for the months from December to July. NATL The region has in the period August-October SST your highest values +2 NIÑo1 The region had the lowest values of TSM. Results on Principal Component Analysis (PCA) identified higher weights in the total variation explained by the first two components, which represent about 100% of the total variance of SST. The Cluster Analysis (AA), the Ward method, allowed the grouping of stations into three homogeneous groups. Keywords: Multivariate Analysis, Climate Change, Global Warming.

Microwave Dielectric Loss Characterization of Silicon Carbide Wafers

2006 ◽  
Vol 527-529 ◽  
pp. 733-736
Author(s):  
Timothy Bogart ◽  
W.J. Everson ◽  
Rick D. Gamble ◽  
Ed Oslosky ◽  
David Snyder ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Dielectric Loss ◽  
Microwave Cavity ◽  
High Yield ◽  
Microwave Dielectric ◽  
Mapping System ◽  
High Frequency Devices ◽  
Nondestructive Characterization ◽  
Initial Results

Semi-insulating silicon carbide (SiC) wafers are important as substrates for high frequency devices such as AlGaN-GaN HEMT’s. A nondestructive characterization technique has been developed to measure the dielectric properties of SiC wafers in the GHz frequency range where the devices will operate in order to validate wafers for high yield working devices. The dielectric loss is measured at approximately 16 GHz in a split microwave cavity. Initial results show a correlation where the dielectric loss decreases as the resistivity increases, where the resistivity was measured using a Contactless Resistivity Mapping system (COREMA). The uniformity of dielectric loss across SiC wafers was evaluated using a split post dielectric resonator cavity fixed at 5.5GHz to measure the dielectric loss at five points on a wafer. Dielectric loss as a function of temperature from room temperature to 400°C was also studied.

scholarly journals EARLINET Raman Lidar Polly<sup>XT</sup>: the neXT generation

2015 ◽  
Vol 8 (7) ◽  
pp. 7737-7780 ◽  
Author(s):  
R. Engelmann ◽  
T. Kanitz ◽  
H. Baars ◽  
B. Heese ◽  
D. Althausen ◽  
...  
Keyword(s):  
Traffic Safety ◽  
Quality Improvements ◽  
Cloud Properties ◽  
Safety Regulations ◽  
Science Community ◽  
Receiver Unit ◽  
Field Campaigns ◽  
Atmospheric State ◽  
532 Nm

Abstract. The atmospheric science community demands for autonomous and quality-assured vertically resolved measurements of aerosol and cloud properties. For this purpose, a portable lidar called Polly was developed at TROPOS in 2003. The lidar system was continuously improved with gained experience from EARLINET, worldwide field campaigns and institute collaborations within the last 10 years. Here we present recent changes of the setup of our portable multiwavelength Raman and polarization lidar PollyXT and the improved capabilities of the system by means of a case study. Our latest developed system includes an additional near-range receiver unit for Raman measurements of the backscatter and extinction coefficient down to 120 m above ground, a water-vapor channel, and channels for simultaneous measurements of the particle linear depolarization at 355 and 532 nm. Quality improvements were achieved by following consequently the EARLINET guidelines and own developments. A modified ship radar ensures measurements in agreement with air-traffic safety regulations and allows 24/7 monitoring of the atmospheric state with PollyXT.

scholarly journals Development of client service as a basis for birth of the electronic commerce system

2021 ◽  
pp. 81-86
Author(s):  
К. A. Zalihina ◽  
Т. N. Sakulyeva
Keyword(s):  
Electronic Commerce ◽  
Customer Service ◽  
21St Century ◽  
Business Processes ◽  
Full Range ◽  
Modern Society ◽  
Level Of Service ◽  
The Internet ◽  
System Research ◽  
The Senses

The purpose of this study is to study the development of customer service as the basis for the emergence of an e-commerce system. Research objectives: to study the aspects of the origin of customer service, to analyse the development of marketplaces abroad and in Russia, to structure expenses when selling goods through the marketplace. The methodology of marketplaces research is based on a deep and thorough study of the needs and moods of customers. The informatization of modern society makes it necessary to adapt business processes to the needs of the consumer, who, due to various factors of the 21st century, are guided by the Internet space, which does not provide the client with a full range of information about the product through the senses. Accordingly, it is necessary to create a level of service that embodies the consumer’s trust in buying goods online.

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