Conceptual design of thermal energy storage systems for near term electric utility applications. Volume 1: Screening of concepts

Over forty thermal energy storage (TES) concepts gathered from the literature and personal contacts were studied for their suitability for the electric utility application of storing energy off-peak discharge during peak hours. Twelve selections were derived from the concepts for screening; they used as storage media high temperature water (HTW), hot oil, molten salts, and packed beds of solids such as rock. HTW required pressure containment by prestressed cast-iron or concrete vessels, or lined underground cavities. Both steam generation from storage and feedwater heating from storage were studied. Four choices were made for further study during the project. Economic comparison by electric utility standard cost practices, and near-term availability (low technical risk) were principal criteria but suitability for utility use, conservation potential, and environmental hazards were considered

Conceptual design of thermal energy storage systems for near term electric utility applications. Volume 2: Appendices - screening of concepts

Volume 2 of this 2 volume report is represented. This volume contains three appendices: (1) bibliography and cross references; (2) taxonomy - proponents and sources; and (3) concept definitions

An eight-month climatology of marine stratocumulus cloud fraction, albedo, and integrated liquid water

As part of the FIRE/Extended Time Observations (ETO) program, extended time observations were made at San Nicolas Island (SNI) from March to October, 1987. Hourly averages of air temperature, relative humidity, wind speed and direction, solar irradiance, and downward longwave irradiance were recorded. The radiation sensors were standard Eppley pyranometers (shortwave) and pyrgeometers (longwave). The SNI data were processed in several ways to deduce properties of the stratocumulus covered marine boundary layer (MBL). For example, from the temperature and humidity the lifting condensation level, which is an estimate of the height of the cloud bottom, can be computed. A combination of longwave irradiance statistics can be used to estimate fractional cloud cover. An analysis technique used to estimate the integrated cloud liquid water content (W) and the cloud albedo from the measured solar irradiance is also described. In this approach, the cloud transmittance is computed by dividing the irradiance measured at some time by a clear sky value obtained at the same hour on a cloudless day. From the transmittance and the zenith angle, values of cloud albedo and W are computed using the radiative transfer parameterizations of Stephens (1978). These analysis algorithms were evaluated with 17 days of simultaneous and colocated mm-wave (20.6 and 31.65 GHz) radiometer measurements of W and lidar ceilometer measurements of cloud fraction and cloudbase height made during the FIRE IFO. The algorithms are then applied to the entire data set to produce a climatology of these cloud properties for the eight month period

Modelling Bathymetric Uncertainty

Modelling depth measurement uncertainty during data collection and processing has become common practice since the release of S-44 4th Edition (IHO, 1998). Hydrographic Offices have also attempted to model uncertainty of legacy bathymetry in order to determine their fitness for various uses. Additional uncertainty can be introduced into representative bathymetry models by various gridding techniques that interpolate depths between measurements. This article reviews sources of measurement uncertainty, looks at methods for estimating uncertainty in legacy data sets and uncer-tainty that is introduced into bathymetry (digital elevation/depth) models (DEMs/DDMs) by gridding. Applications that could benefit from bathymetric/DEM/DDM uncertainty information include bridge risk management and tsunami inundation modelling.Keywords: bathymetry, uncertainty, digital elevation modelsLa modelización de la incertidumbre de las medidas de profundidad durante la recogida y el procesa-do de datos se ha convertido en una práctica común desde la publicación de la 4ª Edición de la S-44 (OHI, 1998). Los Servicios Hidrográficos han intentado también modelar la incertidumbre de la batimetría tradicional para determinar su idoneidad para varios usos. Puede introducirse una incerti-dumbre adicional en modelos de batimetría representativos mediante varias técnicas de reticulado que interpolan profundidades entre las medidas. Este artículo revisa las fuentes de incertidumbre en las medidas, estudia métodos para estimar la incertidumbre en las colecciones de datos tradicionales y la incertidumbre que se introduce en modelos de batimetría (elevación digital/profundidad) (DEMs/DDMs) mediante el reticulado. Las aplicaciones que podrían beneficiar de información relativa a una incertidumbre batimétrica/DEM/DDM incluyen la gestión de los riesgos de puente y la modelización de las inundaciones causadas por los tsunamis.Palabras clave: batimetría, incertidumbre, modelos de elevación digitales.La modélisation de l‘incertitude des mesures des profondeurs pendant la collecte et le traitement des données est devenue pratique commune depuis la publication de la 4ème Edition de la S-44 (OHI, 1998). Les Services hydrographiques se sont également efforcés de modéliser l’incertitude de la bathymétrie traditionnelle afin de déterminer leur aptitude à différentes utilisations. Une incertitude supplémentaire peut être introduite dans des modèles de bathymétrie représentatifs au moyen de différentes techniques de quadrillage qui interpolent les profondeurs entre les mesurages. Cet article passe en revue les sources d‘incertitude dans les mesurages, examine les méthodes d‘estimation de l‘incertitude dans les ensembles de données traditionnels et l‘incertitude introduite dans les modèles d‘élévation ou de profondeurs numériques (DEM/DDM) bathymétriques à l‘aide du quadrillage. Les applications qui pourraient bénéficier d‘informations sur l‘incertitude bathymétrique/DEM/DDM incluent la gestion des risques sur la passerelle et la modélisation des inondations en cas de tsunami.Mots clés : bathymétrie, incertitude, modèles d’élévation numérique

How Polarized Have We Become? A Multimodal Classification of Trump Followers and Clinton Followers

Polarization in American politics has been extensively documented and analyzed for decades, and the phenomenon became all the more apparent during the 2016 presidential election, where Trump and Clinton depicted two radically different pictures of America. Inspired by this gaping polarization and the extensive utilization of Twitter during the 2016 presidential campaign, in this paper we take the first step in measuring polarization in social media and we attempt to predict individuals' Twitter following behavior through analyzing ones' everyday tweets, profile images and posted pictures. As such, we treat polarization as a classification problem and study to what extent Trump followers and Clinton followers on Twitter can be distinguished, which in turn serves as a metric of polarization in general. We apply LSTM to processing tweet features and we extract visual features using the VGG neural network. Integrating these two sets of features boosts the overall performance. We are able to achieve an accuracy of 69%, suggesting that the high degree of polarization recorded in the literature has started to manifest itself in social media as well.Comment: 16 pages, SocInfo 2017, 9th International Conference on Social Informatic

Ozone trends estimated from Umkehr observations made at Edmonton, Alberta, Canada

A Brewer Ozone Spectrophotometer has been in service at the Canadian ozone monitoring station at Stony Plain (53.55 deg N, 114.10 deg W), near Edmonton, Alberta, since 1984. During that time, the instrument has been operated in a fully automated mode that includes the collection of morning and evening Umkehr observations. Some 197 Umkehr observations have been analyzed to make an estimate of the temporal trend in ozone amount at high altitude over the station during the last 8 years. This work has shown that at 40 km the trend in the ozone concentration has been observed to be 0.14 plus or minus 0.10 percent per year

Chimpanzees do not take into account what others can hear in a competitive situation

Chimpanzees (Pan troglodytes) know what others can and cannot see in a competitive situation. Does this reflect a general understanding the perceptions of others? In a study by Hare et al. (2000) pairs of chimpanzees competed over two pieces of food. Subordinate individuals preferred to approach food that was behind a barrier that the dominant could not see, suggesting that chimpanzees can take the visual perspective of others. We extended this paradigm to the auditory modality to investigate whether chimpanzees are sensitive to whether a competitor can hear food rewards being hidden. Results suggested that the chimpanzees did not take what the competitor had heard into account, despite being able to locate the hiding place themselves by the noise

Airborne multiwavelength High Spectral Resolution Lidar (HSRL-2) observations during TCAP 2012 : Vertical profiles of optical and microphysical properties of a smoke/urban haze plume over the northeastern coast of the US

© Author(s) 2014. This work is distributed under the Creative Commons Attribution 3.0 License.We present measurements acquired by the world's first airborne 3 backscatter (β) + 2 extinction (α) High Spectral Resolution Lidar (HSRL-2). HSRL-2 measures particle backscatter coefficients at 355, 532, and 1064 nm, and particle extinction coefficients at 355 and 532 nm. The instrument has been developed by the NASA Langley Research Center. The instrument was operated during Phase 1 of the Department of Energy (DOE) Two-Column Aerosol Project (TCAP) in July 2012. We observed pollution outflow from the northeastern coast of the US out over the western Atlantic Ocean. Lidar ratios were 50-60 sr at 355 nm and 60-70 sr at 532 nm. Extinction-related Ångström exponents were on average 1.2-1.7, indicating comparably small particles. Our novel automated, unsupervised data inversion algorithm retrieved particle effective radii of approximately 0.2 μm, which is in agreement with the large Ångström exponents. We find good agreement with particle size parameters obtained from coincident in situ measurements carried out with the DOE Gulfstream-1 aircraft.Peer reviewedFinal Published versio

MMTF: The Maryland-Magellan Tunable Filter

This paper describes the Maryland-Magellan Tunable Filter (MMTF) on the Magellan-Baade 6.5-meter telescope. MMTF is based on a 150-mm clear aperture Fabry-Perot (FP) etalon that operates in low orders and provides transmission bandpass and central wavelength adjustable from ~5 to ~15 A and from ~5000 to over ~9200 A, respectively. It is installed in the Inamori Magellan Areal Camera and Spectrograph (IMACS) and delivers an image quality of ~0.5" over a field of view of 27' in diameter (monochromatic over ~10'). This versatile and easy-to-operate instrument has been used over the past three years for a wide variety of projects. This paper first reviews the basic principles of FP tunable filters, then provides a detailed description of the hardware and software associated with MMTF and the techniques developed to observe with this instrument and reduce the data. The main lessons learned in the course of the commissioning and implementation of MMTF are highlighted next, before concluding with a brief outlook on the future of MMTF and of similar facilities which are soon coming on line.Comment: 38 pages, 12 figures, 3 tables, now accepted for publication to the Astronomical Journa

Ultra-Slow Discharges That Precede Lightning Initiation

We report on ultra-slowly propagating discharge events with speeds in the range 1-13 km/s, much lower than any known lightning process. The propagation speeds of these discharges are orders of magnitude slower than leader or streamer speeds, but faster than the ion drift speed. For one particular event, a lightning leader forms about 40 ms later within 50 m of the discharge, likely within the same high field region. A second slow event forms 9 ms prior to the initiation, and leads into the negative leader. Most slow events appear to not be directly involved with lightning initiation. This suggests that the classic streamer cascade model of initiation is not always a definitive process. In this work we describe these discharge events displaying unique behavior, their relation to common lightning discharges, and their implications for lightning initiation