2,009 research outputs found

    Regulatory challenges in the move to a low-carbon environment

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    An outcome of the international climate conference in Copenhagen (COP 15, 2009) was that a number of governments have undertaken to reduce their nations\u27 greenhouse gas (GHG) emissions and some have provided targets and deadlines for the achievement of their stated goals. While the transition to a low-carbon environment has the potential to stimulate growth, create jobs and opportunities, and to bring benefits to the economy, there are many challenges in the process. This is an exploratory paper aimed at identifying the major regulatory and governance issues associated with the move to a low-carbon environment. In terms of business governance, CEOs and other executives responsible for corporate oversight will need to monitor, assess, and manage compliance with climate change and carbon-related regulation. In the transition period government regulation encouraging appropriate carbon costs classification and measurement, financial sustainability reporting and disclosure, and responsible carbon citizenship are expected to be predominant.<br /

    Electronic states and optical properties of PbSe nanorods and nanowires

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    A theory of the electronic structure and excitonic absorption spectra of PbS and PbSe nanowires and nanorods in the framework of a four-band effective mass model is presented. Calculations conducted for PbSe show that dielectric contrast dramatically strengthens the exciton binding in narrow nanowires and nanorods. However, the self-interaction energies of the electron and hole nearly cancel the Coulomb binding, and as a result the optical absorption spectra are practically unaffected by the strong dielectric contrast between PbSe and the surrounding medium. Measurements of the size-dependent absorption spectra of colloidal PbSe nanorods are also presented. Using room-temperature energy-band parameters extracted from the optical spectra of spherical PbSe nanocrystals, the theory provides good quantitative agreement with the measured spectra.Comment: 35 pages, 12 figure

    LOFAR Low-band Antenna Observations of the 3C 295 and Boötes Fields: Source Counts and Ultra-steep Spectrum Sources

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    We present Low Frequency Array (LOFAR) Low Band observations of the Boötes and 3C 295 fields. Our images made at 34, 46, and 62 MHz reach noise levels of 12, 8, and 5 mJy beam-1, making them the deepest images ever obtained in this frequency range. In total, we detect between 300 and 400 sources in each of these images, covering an area of 17-52 deg2. From the observations, we derive Euclidean-normalized differential source counts. The 62 MHz source counts agree with previous GMRT 153 MHz and Very Large Array 74 MHz differential source counts, scaling with a spectral index of -0.7. We find that a spectral index scaling of -0.5 is required to match up the LOFAR 34 MHz source counts. This result is also in agreement with source counts from the 38 MHz 8C survey, indicating that the average spectral index of radio sources flattens toward lower frequencies. We also find evidence for spectral flattening using the individual flux measurements of sources between 34 and 1400 MHz and by calculating the spectral index averaged over the source population. To select ultra-steep spectrum (α < -1.1) radio sources that could be associated with massive high-redshift radio galaxies, we compute spectral indices between 62 MHz, 153 MHz, and 1.4 GHz for sources in the Boötes field. We cross-correlate these radio sources with optical and infrared catalogs and fit the spectral energy distribution to obtain photometric redshifts. We find that most of these ultra-steep spectrum sources are located in the 0.7 lsim z lsim 2.5 range

    Form factors for B−−>πlνB-->\pi l\nu decay in a model constrained by chiral symmetry and quark model

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    The form factors for the B−−>πB-->\pi transition are evaluated in the entire momentum transfer range by using the constraints obtained in the framework combining the heavy quark expansion and chiral symmetry for light quarks and the quark model. In particular, we calculate the valence quark contributions and show that it together with the equal time commutator contribution simulate a B-meson pole q^2-dependence of form factors in addition to the usual vector meson B^{*}-pole diagram for B−−>πlνB --> \pi l\nu in the above framework. We discuss the predictions in our model, which provide an estimate of |V_{ub}|^2.Comment: 7 pages, Revtex, 5 figure, fig 3 is replaced and some text is adde

    Prospectus, September 21, 1977

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    ONLY 830.1 NIGHT STUDENTS? PARKLAND NIGHT CLASSES: GOING, GOING, GOING…; Activity Day today: music, food, games; Insurance for Parkland students now available; Parkland Events; Stoeber tops Jones for Stu-Go Vice-Prexy slot; Blue Angels at Willard Airport; Editorial: Who cares for people?; Scholarships are given to area persons; Counseling Service provided: each college division; Parkland news in brief; What to do with a bad case of ivy? Maybe Jack Frost can help; Holograms: three-D images or \u27miracles\u27; 100,000 children hurt each year; SSU invites students to Career Day; U. of I. to burn liquid radioactive wastes; Early books, manuscripts on display in U. of I. Library Rare Book Room; Home health care to be topic at CHI program; Animation Festival at T-Bird will end today; \u27Jazz, Blues and Langston Hughes\u27 to be topic of talk; Young are growing older, old are living longer; Classifieds; Women spikers trample Kankakee; Saskatoon Buzzsaws cut Al \u27Albino\u27 Catfish; Gymnasium: Tennis courts installed; LaBadie pleased with Cross Country team\u27s performance; Sigma Omega participate in walk; New rules this week: Mike O\u27Neill 12 for 12, wins Fast Freddy No. 2; Parkland golfers gracious hosts, finish at bottom in own tournament; Tennis anyone?; Maupin refractures ankle bone, sophomore\u27s status uncertain; Fishbein frys Cobras, first defeat of year; Fast Freddy Football Forecasthttps://spark.parkland.edu/prospectus_1977/1012/thumbnail.jp
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