Optical properties of sea ice doped with black carbon – an experimental and radiative-transfer modelling comparison

Radiative-transfer calculations of the light reflectivity and extinction coefficient in laboratory-generated sea ice doped with and without black carbon demonstrate that the radiative-transfer model TUV-snow can be used to predict the light reflectance and extinction coefficient as a function of wavelength. The sea ice is representative of first-year sea ice containing typical amounts of black carbon and other light-absorbing impurities. The experiments give confidence in the application of the model to predict albedo of other sea ice fabrics. <br><br> Sea ices,  ∼  30 cm thick, were generated in the Royal Holloway Sea Ice Simulator ( ∼  2000 L tanks) with scattering cross sections measured between 0.012 and 0.032 m² kg⁻¹ for four ices. Sea ices were generated with and without  ∼  5 cm upper layers containing particulate black carbon. Nadir reflectances between 0.60 and 0.78 were measured along with extinction coefficients of 0.1 to 0.03 cm⁻¹ (<i>e</i>-folding depths of 10–30 cm) at a wavelength of 500 nm. Values were measured between light wavelengths of 350 and 650 nm. The sea ices generated in the Royal Holloway Sea Ice Simulator were found to be representative of natural sea ices. <br><br> Particulate black carbon at mass ratios of  ∼  75,  ∼  150 and  ∼  300 ng g⁻¹ in a 5 cm ice layer lowers the albedo to 97, 90 and 79 % of the reflectivity of an undoped <q>clean</q> sea ice (at a wavelength of 500 nm)

FIRST REPORT OF NECTAR ROBBING BY SWORD-BILLED HUMMINGBIRDS ENSIFERA ENSIFERA

A growing number of hummingbird species are known to practice nectar robbing. Hummingbirds that rob nectar tend to have short bills and to rob flowers with long, tubular corollas that prevent the birds from accessing nectar through its openings. We document that Sword-billed Hummingbirds Ensifera ensifera, which have the longest bills of any hummingbird species, are secondary nectar robbers on flowers of the red angel’s trumpet Brugmansia sanguinea, which have long tubular corollas and are regularly pollinated by Sword-billed Hummingbirds. When obtaining nectar through the floral opening of B. sanguinea, Sword-billed Hummingbirds' heads may be completely enveloped by the flower, severely limiting their vision. Sword-billed Hummingbirds might be at a lower risk of predation when they rob nectar than when they insert their heads into the floral opening. Thus, nectar robbing in this species might function to reduce predation risk, although we have no data to support this speculation

The Uniform Commercial Code Survey: Introduction

The survey that follows highlights the most important developments of 2018 dealing with domestic and international sales of goods, personal property leases, payments, letters of credit, documents of title, investment securities, and secured transactions

The Uniform Commercial Code Survey: Introduction

The survey that follows highlights the most important developments of 2015 dealing with domestic and international sales of goods, personal property leases, payments, letters of credit, documents of title, investment securities, and secured transactions. Along with the usual descriptions of interesting judicial decisions in these areas, which are highlighted in the survey, there has also been important legislative progress. The 2010 amendments to U.C.C. Article 9 have been adopted in all fifty states, the District of Columbia, and Puerto Rico. Those revisions were summarized in the Introduction to the 2009 survey. Additionally, the 2012 amendments to U.C.C. Article 4A, which address issues related to the implementation of the Dodd-Frank Wall Street Reform and Consumer Protection Act of 2010, have been adopted by forty-four states and the District of Columbia, and introduced in Connecticut, Delaware, and Oklahoma

Melting and Equilibrium Shape of Icosahedral Gold Nanoparticles

We use molecular dynamics simulations to study the melting of gold icosahedral clusters of a few thousand atoms. We pay particular attention to the behavior of surface atoms, and to the equilibrium shape of the cluster. We find that although the surface of the cluster remains ordered up to the melting T_m, the increasing mobility of vertex and edge atoms significantly soften the surface structure, leading to inter- and intra-layer diffusion, and shrinking of the average facet size, so that the average shape of the cluster is nearly spherical at melting.Comment: 4 pages, 4 figures - replaced with final published versio

The Uniform Commercial Code Survey: Introduction

The survey that follows highlights the most important developments of 2019 dealing with domestic and international sales of goods, personal property leases, payments, letters of credit, documents of title, investment securities, and secured transactions

The Impact of the COVID-19 Recovery on California Transportation Revenue: A Scenario Analysis through 2040

The COVID-19 public health emergency has affected every aspect of life in California, reducing social and economic activity. Less activity translates to less travel, and less travel leads to less revenue generated from taxes on motor fuels. As California emerges from the COVID-19 crisis and returns to more normal levels of activity, the state must plan transportation system operations and maintenance in the context of deep uncertainty regarding future revenue. To help decision makers navigate that uncertainty, we used spreadsheet models to estimate the impacts of different economic recovery scenarios from the COVID-19 pandemic on state-generated transportation revenue. Because it is not possible to anticipate future economic conditions, travel volumes, and vehicle markets with certainty, we created six potential economic recovery scenarios and projected future transportation revenue in California through 2040 under each. Scenarios cannot foretell which conditions will predominate in future decades, but scenario analysis helps state officials assess the impact of different economic futures and policy choices, including policies to change the rates of adoption of alternative-fueled vehicles. Key findings include: The projections from the six scenarios demonstrate that California transportation revenue by 2040 could range widely, from as little as $6.5 billion to as much as$10.9 billion, if the assumptions and conditions used to create particular scenarios are realized over time. The cumulative revenue raised between 2020 and 2040 varies by more than $40 billion across the scenarios, from$153 billion to $195 billion. In 2020, taxes on fuels will generate roughly three-quarters of state-generated transportation revenue. By 2040, however, taxes on fuels will generate a much smaller percentage of overall revenue. For example, in four of the six scenarios they generate less than a quarter of revenues

William Schuman's wind band setting of "Be Glad Then, America" (1975): Its history, analysis, and orchestration.

This document seeks to reconcile Be Glad Then, America to the wind band community for consideration in repertoire, particularly in combination with When Jesus Wept and Chester. It contains errata lists for the score and individual parts, and suggestions for alternative scoring to moderate the use of high register in the wind sections. Biographies of Schuman and Billings are provided, along with a history of New England Triptych and Be Glad Then, America. Further, the document includes an analysis of the work, illustrated with score excerpts that correlate its themes to Mourn, Mourn.The historical background, analysis, errata lists, and alternative scoring suggestions provide tools to assist any conductor who wishes to program Be Glad Then, America.The restless energy and exuberant melodies of the first movement made it an attractive repertory prospect for wind band conductors. While the initial response to the publication of Be Glad Then, America was enthusiastic, it was soon apparent that it was considerably less accessible compared to When Jesus Wept and Chester. The score and individual parts contained a large number of errors, and the upper ranges of the wind instruments were over-employed, affecting intonation, balance, and individual stamina. As a result, the piece is rarely programmed.Be Glad Then, America is the wind band setting of the first movement of William Schuman's New England Triptych, an orchestral work published in 1956. Its second and third movements, When Jesus Wept and Chester, were rewritten for band and published in 1957. Schuman published Be Glad Then, America nearly twenty years later at the request of band directors who wished to program all three movements of New England Triptych.New England Triptych was Schuman's tribute to composer William Billings. Like Billings, Schuman valued melody above all other compositional elements. The first movement was based on melodies from the Billings anthem Mourn, Mourn. New England Triptych tied together themes from selected Billings tunes, connecting each section with timpani and snare drum solos