bluuebunny/crossref_metadata_2025 huggingface dataset:
Micro‐blog sentiment classification using Doc2vec + SVM model with data purification
Authors: Liang Yinghong , Liu Haitao , Zhang Su
Published: July 2020

As a Chinese version of twitter, micro‐blog has been popular for many years. On this platform, a lot of comments are generated explosively every day. These comments contain the public's opinions on various topics, which have wide applications in both academic and industrial fields. In recent years, deep learning and some classification algorithms have been applied to sentiment analysis, and good results have been achieved. However, micro‐blog sentiment classification is a challenging task, because micro‐blog messages are short and noisy, and contain massive user‐invented acronyms and informal words. Unfortunately, most researchers pay more attention to analyse the data after deep learning, but only simply remove the noisy data before using algorithm, so the result of sentiment analysis has reached a bottleneck. Here, the authors first purify the data using varied methods before deep learning, then, the Support Vector Machine (SVM) classification algorithm is applied to sentiment classification of micro‐blog using many types of features. Through comparing with the method of simply pre‐processing data, the results show that their approach can improve the performance of micro‐blog sentiment classification effectively and efficiently.
Design of a collaborative monitoring system for hydroelectric generating sets and its application
Authors: Fanwu Chu
Published: July 2020

Diagnosing faults of hydroelectric generating sets (HGS) need the joint efforts of many experts. It is really hard to obtain an accurate interpretation for detected faults relying solely on one independent monitoring system. Therefore, a collaborative monitoring system exploiting independent specialised monitoring systems as the functional unit containing several team members (TMs) has been designed based on facilitator method and team intelligence. Then, the division of labour and responsibilities of each functional unit and communication technology used by TMs in this system are detailed. In addition, this article describes how collaborative monitoring behaviours have been realised through a conversation model based on communication technology. This system provides a good technical support for comprehensive analysis and fault interpretation. A concrete application example is given at the last of this article.
ESA’s Space-Based Doppler Wind Lidar Mission Aeolus – First Wind and Aerosol Product Assessment Results
Authors: Straume A.G. , Rennie M. , Isaksen L. , de Kloe J. , Marseille G.-J. , Stoffelen A. , Flament T. , Stieglitz H. , Dabas A. , Huber D. , Reitebuch O. , Lemmerz C. , Lux O. , Marksteiner U. , Weiler F. , Witschas B. , Meringer M. , Schmidt K. , Nikolaus I. , Geiss A. , Flamant P. , Kanitz T. , Wernham D. , von Bismarck J. , Bley S. , Fehr T. , Floberghagen R. , Parinello T.
Published: July 2020

The European Space Agency (ESA) wind mission, Aeolus, hosts the first space-based Doppler Wind Lidar (DWL) world-wide. The primary mission objective is to demonstrate the DWL technique for measuring wind profiles from space, intended for assimilation in Numerical Weather Prediction (NWP) models. The wind observations will also be used to advance atmospheric dynamics research and for evaluation of climate models. Mission spin-off products are profiles of cloud and aerosol optical properties. Aeolus was launched on 22 August 2018, and the Atmospheric LAser Doppler INstrument (Aladin) instrument switch-on was completed with first high energy output in wind mode on 4 September 2018 [1], [2]. The on-ground data processing facility worked excellent, allowing L2 product output in near-real-time from the start of the mission. First results from the wind profile product (L2B) assessment show that the winds are of very high quality, with random errors in the free Troposphere within (cloud/aerosol backscatter winds: 2.1 m/s) and larger (molecular backscatter winds: 4.3 m/s) than the requirements (2.5 m/s), but still allowing significant positive impact in first preliminary NWP impact experiments. The higher than expected random errors at the time of writing are amongst others due to a lower instrument out-and input photon budget than designed. The instrument calibration is working well, and some of the data processing steps are currently being refined to allow to fully correct instrument alignment related drifts and elevated detector dark currents causing biases in the first data product version. The optical properties spin-off product (L2A) is being compared e.g. to NWP model clouds, air quality model forecasts, and collocated ground-based observations. Features including optically thick and thin particle and hydrometeor layers are clearly identified and are being validated.
Aerosol Investigation During the Arctic Haze Season of 2018: Optical and Microphysical Properties
Authors: Nakoudi Konstantina , Böckmann Christine , Ritter Christoph , Pefanis Vasileios , Maturilli Marion , Bracher Astrid , Neuber Roland
Published: July 2020

In this work, optical and microphysical properties of Arctic aerosol as well as their radiative impact are investigated. Air-borne Lidar observations along with ground-based measurements are evaluated for the Arctic Haze season of 2018. Aerosol abundance as inferred from particle backscatter was typical for this period of the year, with nearly spherical and large particles. The inversion of microphysical properties yielded high Refractive Index (RI) together with low Single-Scattering Albedo (SSA), suggesting absorbing particles. A fitted lognormal volume distribution revealed a fine mode with effective radius (reff) of μm and a coarse mode with reff=0.75 μm. The total radiative balance on ground was positive (12 Wm-2).
Analytical Relationships Between Bulk Microphysical Parameters of Nucleation, Aitken, Accumulation and Coarse Mode Particles and Extinction and Backscatter Coefficients Measured with Lidar
Authors: Kolgotin Alexei , Müller Detlef , Griaznov Vadim , Veselovskii Igor , Korenskiy Mikhail , Ansmann Albert
Published: July 2020

We derive analytical relationships between bulk microphysical parameters of nucleation, Aitken, accumulation and coarse mode particles and extinction and backscatter coefficients measured at wavelengths 355, 532 and 1064 nm. The bulk parameters are represented by number concentration, mean (effective) radius, variance and complex refractive index. Analytical relationships hold true for arbitrarily shaped particles and complex refractive indices m=mR-imI, where mR>>mI. The accuracy is above 60%.
Continuous Lidar Observation of Near Surface Aerosol Using Optical and Sampling Data from Ground-Based Instruments
Authors: Aminuddin Jamrud , Alimuddin Ilham , Tursilowati Laras , Manago Naohiro , Kuze Hiroaki
Published: July 2020

Monitoring of near-surface aerosol is important for both public health issues and radiation budget studies. In this study, we report a continuous observation method of aerosol particles by means of a vertical Mie-scattering lidar in combination with other optical and sampling instruments operated at the ground level. In the Fernald method used for processing the lidar signal, the most appropriate value of lidar ratio at 532 nm is estimated from the Mie-scattering calculation. The input parameters, namely, the mode radius, variance, and both real and imaginary parts of refractive index, are so determined as to reproduce the data from ground-based sampling instruments. Instead of the far-end boundary condition, the extinction coefficient at the surface level is used for constraining the retrieved aerosol extinction profile. The correction of the truncation and relative humidity (RH) effects on the scattering data from the sampling is made with the help of the optical data from a visibility-meter. We discuss the observed features in both low and high RH cases. Such a capability will be useful for uninterrupted lidar observations of near-surface aerosols irrespective of the presence of clouds that often hinders signal observations at higher altitudes where the aerosol-free atmosphere is assumed for the conventional Fernald analysis.
Lidar Derived Fine Scale Resolution Properties of Tropospheric Aerosol Mixtures
Authors: Janicka Lucja , Böckmann Christine , Stachlewska Iwona S. , Wang Dongxiang
Published: July 2020

Fine scale resolution analysis was applied to the complicated aerosol structures observed with the PollyXT-UW lidar over Warsaw during the night of 9/10 August 2015. The full sets of the particle optical properties profiles, so called 3β+2α+2δ+wv (3 backscattering, 2 extinction coefficients, 2 depolarization ratios and water vapour mixing ratio), were obtained to discriminate multiple aerosol height sectors, which were then used for the microphysical properties inversion. The statistical characterization of the main aerosol/mixture types was obtained.
Long-Term Analyses of Aerosol Optical Thickness Using Caliop
Authors: Fujikawa Masahiro , Kudo Rei , Nishizawa Tomoaki , Oikawa Eiji , Higurashi Akiko , Okamoto Hajime
Published: July 2020

We developed an algorithm to derive extinction coefficients for four aerosol components (water-soluble, dust, sea salt, black carbon) from Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) data. The algorithm was applied to the nine-year data for 2007–2015 and the results were compared to CALIOP standard product (CALIOP-ST) and MODerate resolution Imaging Spectroradiometer (MODIS) standard product (MODIS-ST). Comparisons of the total aerosol optical thickness (AOT) showed that MODIS-ST was the largest, followed by CALIOP-ST (Ver.4), and our product. CALIOP-ST (Ver.3) showed a similar magnitude to ours.
Polarization Raman Lidar for Atmospheric Monitoring in the Vipava Valley
Authors: Wang Longlong , Stanič Samo , Eichinger William , Song Xiaoquan , Zavrtanik Marko
Published: July 2020

We report on the design, construction and performance of a polarization Raman lidar, built for atmospheric monitoring in the Vipava valley in SW Slovenia, a regional air pollution hot-spot where aerosols are expected to originate from a number of different sources. Its key features are automatized remote operation capability and indoor deployment, which provide high duty cycle in all weather conditions. System optimization and performance studies include the calibration of the depolarization ratio, merging of near-range (analog) and far-range (photon-counting) data, determination of overlap functions and validation of the retrieved observables with radiosonde data.
Wildfire Smoke in the Stratosphere Over Europe–First Measurements of Depolarization and Lidar Ratios at 355, 532, and 1064 nm
Authors: Haarig Moritz , Baars Holger , Ansmann Albert , Engelmann Ronny , Ohneiser Kevin , Jimenez Cristofer , Althausen Dietrich , Bühl Johannes , Seifert Patric , Mamouri Rodanthi , Nisantzi Argyro
Published: July 2020

Canadian wildfire smoke was detected in the troposphere and lower stratosphere over Europe in August and September 2017. Lidar measurements from various stations of the European Aerosol Research Lidar Network (EARLINET) observed the stratospheric smoke layer. Triple-wavelength (355, 532, and 1064 nm) lidar measurements of the depolarization and the lidar ratio are reported from Leipzig, Germany. The particle linear depolarization ratio of the wildfire smoke in the stratosphere had an exceptional strong wavelength dependence reaching from 0.22 at 355 nm, to 0.18 at 532 nm, and 0.04 at 1064 nm. The lidar ratio increased with wavelength from 40±16 sr at 355 nm, to 66±12 sr at 532 nm, and 92±27 sr at 1064 nm. The development of the stratospheric smoke plume over several months was studied by long-term lidar measurements in Cyprus. The stratospheric smoke layers increased in altitude up to 24 km height.
Characterization of Trace Gases and Green House Gas in Megacity New Delhi
Authors: Choudhary Arti , Kumar Pradeep , Shukla Anuradha , Singh Siddhartha , Singh Abhay Kumar
Published: July 2020

Air pollution and climate change is serious environmental concern due to its visible negative impact on human health. Around 14 Indian cities are placed among top 20 most polluted cities of the world. Trace gas like O3, NOx, CO and CO2 are important pollutants which is associated with human health, climate change and adverse effect on growth and yield of crops. Stratospheric O3 absorbs ultraviolet light and prevents it from reaching to the ground. Greenhouse effect of O3 and CO2 is prominent, O3 in upper troposphere and ranked 3rd for its radiative potential after the carbon dioxide and methane. The amount of O3 generated by photochemical reaction of air pollutants is much larger than the inflow from the stratosphere. This is indicating that trace gases and GHG are generated by anthropogenic activities. It is significantly high in urban area like megacity Delhi as compared to rural area due to excessive anthropogenic activity.

The ground level measurements of surface trace gas like O3, NOx, CO and CO2 were conducted in Delhi-Mathura road near traffic intersection for year 2017, January to December. The daily mean concentration of O3, NOx, CO and CO2 were 23.11±17.26ppb (range 58.38 to 6.42ppb), 26.41±4.24ppb (ranges 48.14 to 24.09ppb), 1.56±4.24ppm (ranges 6.6 to 0.69ppm) and 342.54±33.49 (ranges 508.23 to 323.33ppm), respectively. The mixing ratios of O3 were highest of 32ppbv and lowest 17ppbv during the pre-monsoon and monsoon seasons, respectively. While the mixing ratios of both CO and NOx showed highest and lowest values during the winter and monsoon seasons, respectively.

The analysis concluded seasonality of O3, CO and NOx were also governed by the long-range transport, mainly with the summer and winter monsoon circulations over the Indian subcontinent. The mixing ratios of CO and NOx show strong correlations during winter and pre-monsoon seasons, while poor correlation in the monsoon season. The mixing ratios of CO and NOx decreased with the increase in wind speed, while O3 tended to increase with the wind speed.
Diurnal Variations of CO2 Mixing Ratio in the Lower Atmosphere by Three Wavelength DIAL
Authors: Shibata Yasukuni , Nagasawa Chikao , Abo Makoto
Published: July 2020

We have conducted the measurement of high accurate CO2 mixing ratio profiles by measuring the temperature profiles simultaneously using the three wavelength CO2 DIAL. The measurements of CO2 diurnal variation in the lower atmosphere were carried out on sunny and cloudy days respectively. We find out that increasing of the CO2 mixing ratio occurs over the altitude of about 2 km from the surface during nighttime. On the other hand, the CO2 mixing ratio decreases over the lower atmosphere during daytime. In particular, the CO2 mixing ratio decreases earlier on sunny days than on cloudy days after sunrise. This result suggests that CO2 absorption by photosynthesis greatly contributes to the strength of the solar radiation.
Entrainment and Mixing of Transported Ozone Layers: Implications for Surface Air Quality in the Western U.S.
Authors: Senff Christoph , Langford Andrew , Alvarez Raul , Bonin Tim , Brewer Alan , Choukulkar Aditya , Kirgis Guillaume , Marchbanks Richard , Sandberg Scott , Weickmann Ann , Zucker Michael
Published: July 2020

Recently, two air quality campaigns were conducted in the southwestern United States to study the impact of transported ozone, stratospheric intrusions, and fire emissions on ground-level ozone concentrations. The California Baseline Ozone Transport Study (CABOTS) took place in May – August 2016 covering the central California coast and San Joaquin Valley, and the Fires, Asian, and Stratospheric Transport Las Vegas Ozone Study (FAST-LVOS) was conducted in the greater Las Vegas, Nevada area in May – June 2017. During these studies, nearly 1000 hours of ozone and aerosol profile data were collected with the NOAA TOPAZ lidar. A Doppler wind lidar and a radar wind profiler provided continuous observations of atmospheric turbulence, horizontal winds, and mixed layer height. These measurements allowed us to directly observe the degree to which ozone transport layers aloft were entrained into the boundary layer and to quantify the resulting impact on surface ozone levels. Mixed layer heights in the San Joaquin Valley during CABOTS were generally below 1 km above ground level (AGL), while boundary layer heights in Las Vegas during FAST-LVOS routinely exceeded 3 km AGL and occasionally reached up to 4.5 km AGL. Consequently, boundary layer entrainment was more often observed during FAST-LVOS, while most elevated ozone layers passed untapped over the San Joaquin Valley during CABOTS.
Observation of Wildfire Smoke Transport and PBL Variation During Summer 2018 Listos Campaign in New York City
Authors: Wu Yonghua , Zhao Kaihui , Huang Jianping , Li Dingdong , Arend Mark , Gross Barry , Moshary Fred
Published: July 2020

Air pollution associated with wildfire smoke transport and heat wave in summer pose serious public health concerns in the populated New York City (NYC) area. In this study, we present a synergistic lidar, ceilometer and in-situ observation for wildfire smoke transport and planetary-boundary-layer (PBL) variation in the NYC urban and coastal area during the summer 2018 Long Island Sound Tropospheric Ozone (O3) Study (LISTOS). A dense smoke plume and mixing into PBL on August 15-17, 2018 was analyzed while the coincident enhancement of PM2.5, CO and O3 exceedance of NAAQS was demonstrated from both the observation and model. In addition, we show the temporal-spatial variation and difference of the PBL-height (PBLH) in the NYC urban and its coastal vicinity. We further evaluate the NAM-CMAQ model forecast of O3, PM2.5 and PBLH with the ground observations.
Observations of the Nickel Layer in the Mesopause Region at Mid-Latitudes
Authors: Gerding Michael , Baumgarten Kathrin , Plane John M. C.
Published: July 2020

Observations of the mesospheric Ni layer have been performed by lidar in January-March 2018 at Kuehlungsborn/Germany (54°N, 12°E). These soundings provide only the second Ni data set after initial observations by Collins et al. at Chatanika/Alaska (65°N, 147°W)[1]. We utilized for the first time a transition from the low-lying excited Ni(3D) state at 341 nm. For all soundings, nightly mean peak densities varied between ~280 cm−3 and 450 cm3, which is a factor of ~40 less than previously reported for Chatanika [1]. The observed Ni abundance is especially important if compared with the abundance of other metals like Fe, and with their respective abundances in evaporating meteoroids, which form the source of the metal layer in the upper mesosphere. Here, we present exemplarily a sounding from January 8, 2018. Beside the Ni raw data and density profiles we show a temperature profile as measured simultaneously be the co-located RMR lidar and the temperature variation due to gravity waves and tides.
A Recipe to Obtain Lidar Polarisation Calibration Parameters G, H and K
Authors: Buxmann Joelle , Osborne Martin , Georgoussis George , Freudenthaler Volker
Published: July 2020

The accuracy of the polarisation calibration is of prime importance for aerosol classification using lidars. We present a detailed description how to obtain the calibration parameters introduced in 2016 [1] accounting for various effects of non-ideal optics, lasers and atmospheric conditions. We find that crucial parameters such as the rotation angle of the plane of polarisation of the Laser (RotL) as well as the degree of linear polarisation (DOLP) influence the volume linear depolarisation ratio significantly.
Biomass Burning Measurements in Earlinet
Authors: Adam Mariana , Nicolae Doina , Belegante Livio , Stachlewska Iwona S. , Szczepanik Dominika , Mylonaki Maria , Papanikolaou Christiana Anna , Siomos Nikolaos , Voudouri Kalliopi A. , Apituley Arnoud , Alados-Arboledas Luca , Bravo-Aranda Juan Antonio , Pietruczuk Aleksander , Chaikovski Anatoli , Sicard Michaël , Muñoz-Porcar Constantino , Mattis Ina , Papagiannopoulos Nikolaos , Mona Lucia , Baars Holger , Wandinger Ulla , Bortoli Daniele , Grigorov Ivan , Peshev Zahary , Antonescu Bogdan
Published: July 2020

The biomass burning events are analyzed using the EARLINET-ACTRIS atmospheric profiling of aerosols using lidars. The period of 2008-2017 was chosen to analyze all the events assigned in the EARLINET database under Forest Fire category. A number of fourteen stations were considered. The data provided, ranged from complete data sets (backscatter, extinction and particle linear depolarization ratio) to single profiles (backscatter coefficient). A thorough quality control was performed. Smoke layers geometry was evaluated and the mean properties within each layer were computed. The Hysplit backward-trajectory technique and the FIRMS fire database were used to double check the source of each layer. Discussions were made under the following scenarios: fire events seen by two stations, long range transport from North America, and geographical clusters.
Observation of the Urban Wind Island Effect
Authors: Baidar Sunil , Bonin Tim , Choukulkar Aditya , Brewer Alan , Hardesty Mike
Published: July 2020

Urban wind island effect (UWI) is defined as a phenomenon in which boundary layer mean wind speeds in an urban area are noticeably higher than its neighboring rural areas. Unlike urban heat island effect which has been extensively studied, the UWI was only recently observed in a modeling study. Here we study existence of the UWI over Indianapolis, Indiana using wind profile measurements from two Doppler wind lidars (DWL) that were deployed in climatologically upwind and downwind of the city. Under certain atmospheric conditions higher wind speeds and turbulence were observed at the downwind site over the entire urban boundary layer outside the urban canopy layer.
Operation of the Airborne 355-nm High Spectral Resolution and Doppler Lidar LNG
Authors: Bruneau D. , Pelon J. , Blouzon F. , Cazenave Q. , Collomb H. , Irbah A. , Mariscal J-F , Delanoë J.
Published: July 2020

High spectral resolution lidar (HSRL) are known to offer capabilities of separating attenuated aerosol and molecular backscattering so that particle extinction and backscattering can be separately retrieved. UV operation provides high energy in eye-safety conditions. Further to that, it could be important for most meteorological or environmental studies to get wind measurements at the same time. LNG is now the only HSR Doppler Lidar (HSRDL) system capable of this. Results obtained during ground-based and airborne measurements show that the backscatter and extinction coefficients at 355 nm can be measured with a relative precision better than 10% (adjusting altitude and time resolution from 60 m to 240 m and 30s to 2mn, respectively) in aerosol layers of 0.5 10−6 m−1 sr−1 backscatter coefficient from ground and aircraft. The same relative precision is obtained in cirrus clouds of a 10−5 m−1 sr−1 backscatter coefficient. The capacity of the system to perform wind velocity measurements has also been demonstrated with precisions in the range of 1 to 2 ms−1 in same conditions. We present the main characteristics and illustrate observational capabilities from ground-based and airborne measurements.
Remote Sensing of Atmospheric Turbulence Profiles by Laser Guide Stars
Authors: Qiang Xiwen
Published: July 2020

Ranged-resolved profiles of atmospheric turbulence are necessary and important for many applications in astronomical and adaptive optics communities. In order to characterize the vertical atmospheric structure in field, a technique is put forward to remote sensing ranged-resolved profiles of atmospheric turbulence by combined with laser guide stars and differential image motion method. Laser guide stars are formed at several successive altitudes by projecting pulsed laser, returned signals of images are received by a optical system with two receiving telescopes, and variance of centroids′ distance is derived from the images with two spots at the same altitude. So, based on a inversion algorithm, atmospheric turbulence profiles are retrieved from differential image motion variance of distance of centroids at various altitudes. The structure constants of refractive index of atmosphere range from 10-14m-2/3 at lower altitudes to 10-16m-2/3 at higher altitudes are remote sensed experimentally. The results show it is a effective method that combined laser guide stars with differential image motion method and could sense atmospheric turbulence profiles remotely in real time.
Towards Developing a Micropulse Differential Absorption Lidar to Measure Atmospheric Temperature
Authors: Stillwell Robert A. , Spuler Scott M. , Hayman Matthew , Bunn Catharine E. , Repasky Kevin S.
Published: July 2020

It has generally been assumed that differential absorption lidar (DIAL) systems are incapable of measuring atmospheric temperature with useful accuracy. This assumption is a direct result of errors that arise in standard DIAL retrievals due to differential Rayleigh-Doppler broadening from aerosols and molecules. We present here, a combined high spectral resolution (HSRL) and DIAL system that addresses this identified source of uncertainty by measuring quantitative aerosol parameters as well as oxygen absorption parameters. This system, in combination with a perturbative retrieval method, accounts for the Rayleigh-Doppler broadening effects on the oxygen absorption. We describe this combined DIAL/HSRL system and retrieval to evaluate the first retrieval parameters exploring the likelihood that it is possible to measure atmospheric temperature using a DIAL system.
Experimental Determination of Lidar Overlap Profile Based on Dual Field-of-View High Spectral Resolution Lidar
Authors: Wang Nanchao , Shen Xue , Zhou Yudi , Liu Chong , Zhang Yupeng , Ke Ju , Xiao Da , Zhong Tianfen , Rong Yuhang , Wang Binyu , Chen Jie , Liu Dong
Published: July 2020

This paper presents two approaches to calibrate the overlap factor under inhomogeneous atmospheric condition without critical assumption and delivers detailed analysis about the retrieval errors of overlap profile in High-Spectral-Resolution-Lidar (HSRL). The first method employs an additional optical subsystem with different field-of-view, that is dual field-of-view HSRL, for the retrieval of overlap profile. The second method takes advantage of the difference of the result between the HSRL and Klett method, that is about the retrieval of backscatter coefficient for uncorrected lidar signal, to correct overlap profile. Surprisingly, two methods show very high-level consistency and stability of the result. It is potential that this technique would be an excellent solution for experimental determination of lidar overlap in ground-based HSRL.
Lidar Technology Based on Fiber System and its Application
Authors: Cheng Xuewu , Xia Yuan , Yang Yulian , Lin Xin , Yang Yong , Liu Linmei , Li Faquan
Published: July 2020

The sodium atom existed in the metal layer of the earth’s atmosphere has a high atomic number density and a large scattering cross section. Sodium layer can act as a good tracer for atmospheric detection in the middle and lower-thermosphere (MLT) region. The sodium fluorescence lidar uses ultrashort pulsed laser to excite sodium atoms, which enabling simultaneous detection of wind and temperature in the middle and upper atmosphere. This paper reports on the development of sodium fluorescence laser radar in recent years, especially the integration of fiber-coupled optical switches and fiber-coupled acousto-optic frequency modulation technologies, which greatly improved the stability and reliability of lidar system and reduced the maintenance of lidar operation, laying a good foundation for the application of lidar observations under harsh environments. This technology has been applied to the sodium wind/temperature lidar in Yangbajing, Tibet and has been running stably for a long time.
The ESA-EVE Polarization Lidar for Assessing the Aeolus Aerosol Product Perfomance
Authors: Paschou Peristera , Proestakis Emmanouil , Tsekeri Alexandra , Siomos Nikos , Gkikas Antonis , Gialitaki Anna , Marinou Eleni , Binietoglou Ioannis , Meleti Charikleia , Freudenthaler Volker , Georgoussis George , Doxastakis George , Louri-das Alexandros , Von Bismarck Jonas , Amiridis Vassilis
Published: July 2020

We present the EVE lidar concept, a combined linear/circular polarization system, tailored to evaluate the spaceborne ALADIN Doppler lidar system aerosol retrievals. EVE, currently under development, aims to provide the ESA-Aeolus mission with a flexible, mobile reference ground-based lidar system capable of providing well-characterized fiducial reference measurements of aerosol optical properties. Since ALADIN detects only the co-polar component of the backscattered circularly polarized radiation, a portion of the received radiation gets lost, leading to an un-derestimation of the backscatter coefficient and the circular depolarization ratio in strongly depolarizing scenes with non-spherical particles. The main focus of the new EVE lidar is to quantify these uncertainties and to evaluate aerosol backscatter/extinction retrievals for Aeolus, and later also for EarthCARE product validation, quality assessment and improvement.
Three-Dimensional Laser Imaging Based on a Photon-Counting Avalanche Photodiode Array
Authors: Ge Peng , Chen Cong , Shang Zhen , Fan Yanen , Guo Jingjing , Zhuang Zibo , Ge Jialong
Published: July 2020

Photon-counting detector array is very desired for high-resolution laser imaging based on direct time-of-flight measurement. Such systems have potential applications in remote sensing with long distances. We will perform three-dimensional imaging using a large InGaAs Geiger-mode avalanche photodiode array which has single-photon sensitivity. To improve the image quality with only a few photon detections, the photon counting imaging process is analyzed and a regularization method based on pixel spatial correlation is employed for image reconstruction. The performance of the method is compared with that of conventional maximum likelihood estimation on intensity and range image reconstructions of a building about six hundred meters away.
A New Method for a Side-Scattering Lidar to Retrieve the Aerosol Backscattering Coefficient
Authors: Wang Zhenzhu , Tao Zongming , Liu Dong , Xie Chenbo , Wang Yingjian
Published: July 2020

The side-scattering lidar based on the CCD camera is a powerful tool to measure the near- ground aerosol, which is most interesting for the environmental and meteorological departments. The inversion method for the side-scattering lidar is different from the conventional Fernald method due to the differences in two lidar equations. A new inversion method for the side-scattering lidar to retrieve the aerosol backscattering coefficient is proposed for the first time, which is based on the aerosol backscattering coefficient at the ground as a restriction condition. Numerical simulation is used to analyze the convergence of this new method. Case studies indicate that this new method is reasonable and feasible.REFERENCES
Aerosol - Cloud Target Classification in HALO Lidar/Radar Collocated Measurements
Authors: Marinou Eleni , Ewald Florian , Gross Silke , Wirth Martin , Schaefler Andreas , Cazenave Quitterie , Delanoë Julien
Published: July 2020

Particle attenuated backscatter and depolarization ratio at 532 nm from the WALES (Water Vapor Lidar Experiment in Space) instrument are used in combination with the radar reflectivity from the 35 GHz MIRA35 cloud radar in order to perform an aerosol-cloud target classification on the lidar/radar collocated observations carried out with the High Altitude and LOng-range research aircraft (HALO), in high temporal and spatial resolution.

The methodology is applied to the measurements conducted during the North Atlantic Waveguide and Downstream Impact Experiment (NAWDEX) in fall 2016. Here, we present one case study to show the feasibility and information context of the aerosol-cloud discrimination, which can serve as a good complement to the Cloud target categorization applied already in the measurements. Our results demonstrate that the developed mask is capable to identify complex stratifications with different aerosol and cloud types and even aerosol layers of low signal.
Aerosol Typing Based on Multiwavelength Lidar Observations and Meteorological Model Data
Authors: Mylonaki Maria , Giannakaki Elina , Papayannis Alexandros , Floca Elena , Komppula Mika
Published: July 2020

Three different aerosol classification methods have been used to characterize lidar observations: Mahalanobis distance automatic aerosol type classification, Neural Network Aerosol Typing Algorithm (NATALI) and Source and Analysis (SCAN) aerosol classification. The data selection has been made through the EARLINET database depending on the 3b+2a+1δ optical property availability. One hundred aerosol layers from four EARLINET stations (Bucharest, Kuopio, Leipzig and Potenza) have been classified. We present a typical case study of aerosol characterization observed by the MUSA system over Potenza on the 11th of April 2016 (20:30-21:30 UTC).
Monitoring Ice Crystals Clouds: Investigation of the Lidar Depolarization Ratios
Authors: Voudouri Kalliopi – Artemis , Giannakaki Elina , Komppula Mika , Gialitaki Anna , Natsis Athanasios , Balis Dimitris
Published: July 2020

A cirrus cloud dataset from a groundbased lidar in a sub-arctic station is analyzed in terms of the particle depolarization ratio. The depolarization values -δ- showed a broad distribution, ranging between 0.25 and 0.7, with a mean value of 0.38 ± 0.07. This variability is examined in correlation with temperature dependencies and the cirrus optical depth. Depolarization values greater than 0.45 are observed from temperatures between -60oC and -40oC, where horizontally oriented planar ice crystals are to be expected. Two case studies are also, discussed and analyzed in terms of depolarization height dependence.
Optical Properties of Canadian Biomass Burning Particles Over Europe Observed with Calipso and Ground-Based Lidar Systems
Authors: Papanikolaou Christina-Anna , Giannakaki Elina , Papayannis Alex , Tombrou Maria , Mylonaki Maria , Soupiona Ourania
Published: July 2020

A long-lasting biomass burning event affected Europe from 27 August to 3 September 2018. The biomass burning aerosol layers were observed with ground- and space-based lidars in heights ranged between 2-7 km (a.s.l.). The mean backscatter coefficient for the ground-based stations ranged between 0.29 and 1.51 Mm-1sr-1, while the CALIPSO retrieved values ranged between 0.43 and 1.83 Mm-1sr-1. Moreover, the mean Ångström exponent (AEb) values, relevant to backscatter, ranged from 0.83 to 1.04 for the aforementioned lidar stations. At the same time, the mean AEb values obtained from CALIPSO ranged between 0.17 and 1.89. The mean particle depolarization ratio ranged between 0.037 and 0.080.
Retrieval of Aerosol Optical Properties Based on High Spectral Resolution Lidar
Authors: Xiao Da , Zhong Tianfen , Shen Xue , Wang Nanchao , Rong Yuhang , Liu Chong , Zhang Yupeng , Liu Dong
Published: July 2020

The detection of clouds and aerosols is important for climate research. Lidar has been widely used in atmospheric remote sensing research because of its high spatial and temporal resolution and ability to detect profiles. High spectral resolution lidar (HSRL) accurately calculates the optical properties of aerosols and clouds without relying on any assumptions. Based on the 532nm iodine HSRL system, the lidar ratio of the urban aerosol in Hangzhou is 40-50sr, and the average lidar ratio of the cirrus is 24.79sr, demonstrating that the HSRL system and retrieval algorithms accurately obtain the optical properties of clouds and aerosols.
The Depolarization Properties of Cirrus Cloud by Lidar: Observation and Model Match
Authors: Wang Zhenzhu , Borovoi Anatoli , Matvienko Gennady , Liu Dong , Xie Chenbo , Wang Yingjian , Konoshonkin Alexander , Kustova Natalia
Published: July 2020

The Polarization Lidar has been developed for cirrus cloud optical properties measurement. The Nd-YAG laser is employed as emitting linear source and two channels are used for detecting back-scattering signals from cirrus cloud including two 532 nm Orthogonal Polarization channels. Measurements were carried out from December 2010, to February 2013. In this work, we consider the only linear depolarization ratio measured at a wavelength of 532 nm. The dependences of depolarization ratios on both the size of ice crystals and the distribution of their distortion angles were also calculated. These results were compared with each other and used for retrieving the microphysical parameters of cirrus clouds observed in Hefei.
Two Parameter-Retrieval Algorithms of Aircraft Wake Vortex with Doppler Lidar in Clear Air
Authors: Shen Chun , Li Jianbing , Gao Hang
Published: July 2020

Aircraft wake is a pair of strong counter-rotating vortices generated behind an aircraft, which might be very hazardous to a flowing aircraft and the detection of which has attracted much attention in aviation safety field. This conference paper introduces two parameter-retrieval algorithms, i.e., Optimization method and Max-min method. They have been integrated into a toolbox and can retrieve the parameters of wake vortex efficiently and robustly.
Processing of high-grade zeolite nanocomposites from solid fuel combustion by-products as critical raw materials substitutes
Authors: Boycheva Silviya , Zgureva Denitza , Lazarova Hristina , Lazarova Katerina , Popov Cyril , Babeva Tsvetanka , Popova Margarita
Published: July 2020

High-grade zeolite nanocomposites are synthesized utilizing solid by-products from combustion of coal for energy production in Thermal Power Plants applying alkaline aging, hydrothermal and fusion-hydrothermal activation procedures. The obtained coal ash zeolites were studied with respect to their chemical and phase composition, morphology, surface parameters and thermal properties. It was found that they are distinguished in nanocrystalline morphology and significant content of iron oxide nanoparticles (γ-Fe2O3, α-Fe2O3, γ-Fe3O4) and doping elements (Cu, Co, Mn, V, W, etc.) transferred from the raw coal ash, and therefore they are assumed as nanocomposites. Coal fly ash zeolite nanocomposites are characterized by a mixed micro-mesoporous texture, significant concentration of acidic Brønsted centers due to their high surface insaturation, high chemical and thermal stabilty. This unique combination of compositional and textural properties predetermines the application of these materials as catalysts for thermal oxidation processes, anticorrosion barrier coatings, carbon capture adsorbents, matrices for hosting functional groups, detergents etc. Examples for coal fly ash zeolite applications for substitution of critical raw materials in practice are provided.
Ängste im Umgang mit suizidalen Patient/innen: Eine
vergleichende Untersuchung von approbierten Psychotherapeut/innen und
Psychotherapeut/innen in Ausbildung
Authors: Conrad Katharina , Teismann Tobias , Rath Dajana , Forkmann Thomas
Published: July 2020

Theoretischer Hintergrund Ein Patient/innensuizid stellt die
am häufigsten genannte, berufsbezogene Befürchtung von
Psychotherapeut/innen dar. In der vorliegenden Untersuchung sollen
Ängste im Umgang mit suizidalen Patient/innen spezifiziert
werden – sowohl bei approbierten Psychotherapeut/innen (aPT)
als auch bei Psychotherapeut/innen in Ausbildung (PiA). Die
Ergebnisse sollen zudem mit einer analogen Erhebung von 1996 verglichen
werden.

Methode N=271 Psycholog/innen, davon n=90 aPT
und n=181 PiA, nahmen an einer Onlinebefragung teil. Erfasst wurden
Ängste im Umgang und berufliche Erfahrungen mit suizidalen
Patienten/innen anhand des Fragebogens zur Erfassung von
Therapeutenängsten von Dorrmann (2016). Zudem wurde mithilfe eines
selbstkonstruierten Tests suizidbezogenes Wissen erfragt. Folgende
Hypothesen wurden überprüft: (1) aPT haben weniger
Ängste im Umgang mit suizidalen Patienten/innen als PiA, (2)
PiA und aPT unterscheiden sich im Hinblick auf ihr Wissen und ihre Erfahrung
zum Thema Suizidalität, (3) die Ergebnisse der aktuellen Befragung
ergeben weniger Ängste bei Psychotherapeut/innen als die
Ergebnisse einer vergangenen Befragung von Dorrmann (1996).
Schließlich wurde folgende explorative Fragestellung untersucht: Hat
der Status (aPT vs. PiA) Auswirkungen auf die Ängste vermittelt
über die Erfahrung sowie das Wissen?

Ergebnisse Die folgenden Ängste werden von
Therapeut/innen am häufigsten berichtet: Angst vor
Schuldgefühlen/Selbstvorwürfen nach einem
Suizidversuch/Suizid, Angst vor Fehleinschätzungen und den
damit verbundenen Konsequenzen, Angst vor juristischen Konsequenzen nach
einem Suizidversuch/Suizid, Angst vor Vorwürfen durch Andere
(Angehörige des Patient/innen/Kolleg/innen)
nach einem Suizidversuch/Suizid. PiA berichten stärkere
Ängste im Umgang mit suizidalen Patient/innen als aPT. Die
berufliche Erfahrung mediiert den Zusammenhang zwischen beruflichem Status
und Ängsten. Im Vergleich berichten Therapeut/innen heute
von weniger Ängsten als vor 20 Jahren.

Schlussfolgerung Therapeut/innen fürchten sich
v. a. vor den Folgen eines Suizidversuchs/Suizids. Insgesamt
sind Ängste jedoch nur in moderater Form vorhanden und scheinen
heute geringer ausgeprägt zu sein als vor 20 Jahren. Es
lässt sich mutmaßen, dass eine zunehmende
Professionalisierung des therapeutischen Umgangs mit suizidalen Patienten zu
einer Reduktion von Therapeutenängsten beigetragen hat.
kurz & bündig
Authors: Kroggel Lena
Published: July 2020

Tai Chi kann als achtwöchiges Achtsamkeitstraining die Kernsymptome von Schulkindern mit ADHS reduzieren.
„Bitte hören Sie nicht auf, sich für Ihre Interessen zu engagieren“ – Dr. Achim Kessler zum Gesundheitssystem in Deutschland
Authors: Kessler Achim , Mischner Julia
Published: July 2020

Als Mitglied des Gesundheitsausschusses im Bundestag setzt sich Dr. Achim Kessler von DIE LINKE dafür ein, dass sich die Gesundheitsversorgung hierzulande vor allem an den Bedürfnissen der Menschen orientiert. Dabei setzt er sich auch für die Anliegen der Heilmittelerbringer ein.
Proximalized Total Arch Replacement Can Be Safely Performed by Trainee
Authors: Nakanishi Sentaro , Wakabayashi Naohiro , Ise Hayato , Kitahara Hiroto , Hirofuji Aina , Ishikawa Natsuya , Kamiya Hiroyuki
Published: July 2020

Background The aim of the present study was to validate safety of total arch replacement (TAR) using a novel frozen elephant trunk device, operated by trainees as surgical education.

Methods Sixty-four patients including 19 patients (29.6%) with acute aortic dissection type A (AADA) underwent TAR in our institute between April 2014 and March 2019 were retrospectively analyzed. Twenty-nine patients were operated by trainees (group T) and 35 patients were operated by attending surgeons (group A).

Results Patient characteristics did not differ between groups. Operative time (409.4 ± 87.8 vs. 468.6 ± 129.6 minutes, p = 0.034), cardiopulmonary bypass time (177.7 ± 50.4 vs. 222.9 ± 596.7 minutes, p = 0.019), and hypothermic circulatory arrest time (39.5 ± 13.4 vs. 54.5 ± 18.5 minutes, p = 0.001) were significantly shorter in group A than in group T, but aortic clamping time did not differ between groups (115.3 ± 55.7 vs. 114.2 ± 35.0 minutes, p = 0.924) because the rate of concomitant surgery was higher in group A (37.1 vs. 10.3%, p = 0.014). Thirty-day mortality was 3.1% in the entire cohort. Although operation time was longer in group T, there were no significant difference in postoperative results between the groups, and the experience levels of the main operator were not independent predictors for in-hospital mortality + major postoperative complications. There was no difference in late death and aortic events between groups.

Conclusions The present study demonstrated that TAR can be safely performed by trainees, and suggests TAR as a possible and safe educational operation.
Velocity jump processes: An alternative to multi-timestep methods for faster and accurate molecular dynamics simulations
Authors: Monmarché Pierre , Weisman Jérémy , Lagardère Louis , Piquemal Jean-Philip
Published: July 2020

We propose a new route to accelerate molecular dynamics through the use of velocity jump processes allowing for an adaptive time step specific to each atom–atom pair (two-body) interactions. We start by introducing the formalism of the new velocity jump molecular dynamics, ergodic with respect to the canonical measure. We then introduce the new BOUNCE integrator that allows for long-range forces to be evaluated at random and optimal time steps, leading to strong savings in direct space. The accuracy and computational performances of a first BOUNCE implementation dedicated to classical (non-polarizable) force fields are tested in the cases of pure direct-space droplet-like simulations and of periodic boundary conditions (PBC) simulations using Smooth Particle Mesh Ewald method. An analysis of the capability of BOUNCE to reproduce several condensed-phase properties is provided. Since electrostatics and van der Waals two-body contributions are evaluated much less often than with standard integrators using a 1 fs time step, up to a 400% direct-space acceleration is observed. Applying the reversible reference system propagator algorithms [RESPA(1)] to reciprocal-space (many-body) interactions allows BOUNCE-RESPA(1) to maintain large speedups in PBC while maintaining precision. Overall, we show that replacing the BAOAB standard Langevin integrator by the BOUNCE adaptive framework preserves a similar accuracy and leads to significant computational savings.
A novel abrasive water jet machining technique for rapid fabrication of three-dimensional microfluidic components
Authors: Azarsa Ehsan , Jeyhani Morteza , Ibrahim Amro , Tsai Scott S. H. , Papini Marcello
Published: July 2020

Microfluidic lab-on-a-chip devices are usually fabricated using replica molding, with poly(dimethylsiloxane) (PDMS) casting on a mold. Most common techniques used to fabricate microfluidic molds, such as photolithography and soft lithography, require costly facilities such as a cleanroom, and complicated steps, especially for the fabrication of three-dimensional (3D) features. For example, an often-desired 3D microchannel feature consists of intersecting channels with depth variations. This type of 3D flow focusing geometry has applications in flow cytometry and droplet generation. Various manufacturing techniques have recently been developed for the rapid fabrication of such 3D microfluidic features. In this paper, we describe a new method of mold fabrication that utilizes water jet cutting technology to fabricate free-standing structures on mild steel sheets to make a mold for PDMS casting. As a proof-of-concept, we use this fabrication technique to make a PDMS chip that has a 3D flow focusing junction, an inlet for the sample fluid, two inlets for the sheath fluid, and an outlet. The flow focusing junction is patterned into the PDMS slab with an abrupt, nearly stepwise change to the depth of the microchannel junction. We use confocal microscopy to visualize the 3D flow focusing of a sample flow using this geometry, and we also use the same geometry to generate water-in-oil droplets. This alternative approach to create microfluidic molds is versatile and may find utility in reducing the cost and complexity involved in fabricating 3D features in microfluidic devices.