4,332 research outputs found

    Initial investigation of the wavelength dependence of optical properties measured with a new multi-pass Aerosol Extinction Differential Optical Absorption Spectrometer (AE-DOAS)

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    Atmospheric aerosols directly affect climate by scattering and absorbing radiation. The magnitude of the impact is dependent upon the wavelength of light, but is often estimated near 550 nm. When light scattering and absorption by aerosols is approximated, the wavelength dependence of the refractive index for speciïŹc components is lost. As a result, climate models would have inherent uncertainties for aerosol contributions to radiative forcing when considering the entire solar spectrum. An aerosol extinction differential optical absorption spectrometer has been developed to directly measure aerosol extinction at mid-ultraviolet to near infrared wavelengths. The instrument consists of a spectrometer coupled to a closed White-type multi-pass gas cell with an adjustable path length of up to approximately 20 m. Laboratory measurements of various gases are compared with known absorption cross sections. Additionally, the extinction of monodisperse samples of polystyrene latex spheres are measured and compared to Mie theory generated with refractive index values from the literature to validate the new instrument. The polystyrene experiments also emphasize the ability of the new instrument to retrieve the wavelength dependent refractive index, especially in the ultraviolet wavelength regions where variability is expected. The spectrometer will be a signiïŹcant advancement for determining wavelength dependent complex refractive indices in future laboratory studies as well as provide the ability to monitor ambient aerosol light extinction

    The Toll for Traveling Students: Durational-Residence Requirements for In-State Tuition after \u3cem\u3eSaenz v. Roe\u3c/em\u3e

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    After the excitement of getting into the college of her choice wears off, a student may soon wonder how she will pay for her newfound prize. Though higher education is almost always a sound investment given its potentially tremendous return and importance in getting a good job, the cost is daunting- sometimes even prohibitive-for many students. Public undergraduate and graduate schools are an attractive option for many students because of lower tuitions. Yet state universities deny many students the full measure of this benefit. Public universities usually charge significantly higher tuition rates to out-of-state students than in-state students. A nonresident student may find herself paying as much as three times what her resident counterparts pay. Consequently, a student\u27s classification as a resident or nonresident may determine whether she can afford higher education. State statutes and school regulations often require that students have resided in the state for at least a year before they can be classified as residents for tuition purposes. As a result, state colleges frequently deny many students the benefit of lower tuition for at least a year, regardless of their intentions to make the state their permanent home. These sorts of waiting periods, which require that a person have resided in a state for a particular period of time before she is entitled to a benefit, are called durational-residence requirements. Durational-residence requirements raise a red flag for many constitutional law scholars because the Supreme Court has struck down many-though not all-of them. It is therefore unsurprising that many lawyers and scholars have argued that durational-residence requirements for in-state tuition are unconstitutional. Nevertheless, no court has found these requirements unconstitutional. Despite that no challenge has succeeded, this Note contends that durational-residence requirements for in-state tuition at public colleges and universities do indeed violate the fundamental right to travel. Part I argues that Saenz\u27s portability distinction is illusory and should not preclude the decision\u27s reasoning from applying to requirements for college tuition. Part II then asserts that because Saenz has moved from a severe-penalties rule to a nondiscrimination rule, courts should apply strict scrutiny in evaluating durational-residence requirements for in-state tuition. Furthermore, this movement undoes the reasoning behind pre-Saenz precedent that declined to apply heightened scrutiny. Finally, Part III argues that these requirements should fail strict scrutiny because either the state interests are not compelling or the means are not narrowly tailored to those interests

    The Toll for Traveling Students: Durational-Residence Requirements for In-State Tuition after \u3cem\u3eSaenz v. Roe\u3c/em\u3e

    Get PDF
    After the excitement of getting into the college of her choice wears off, a student may soon wonder how she will pay for her newfound prize. Though higher education is almost always a sound investment given its potentially tremendous return and importance in getting a good job, the cost is daunting- sometimes even prohibitive-for many students. Public undergraduate and graduate schools are an attractive option for many students because of lower tuitions. Yet state universities deny many students the full measure of this benefit. Public universities usually charge significantly higher tuition rates to out-of-state students than in-state students. A nonresident student may find herself paying as much as three times what her resident counterparts pay. Consequently, a student\u27s classification as a resident or nonresident may determine whether she can afford higher education. State statutes and school regulations often require that students have resided in the state for at least a year before they can be classified as residents for tuition purposes. As a result, state colleges frequently deny many students the benefit of lower tuition for at least a year, regardless of their intentions to make the state their permanent home. These sorts of waiting periods, which require that a person have resided in a state for a particular period of time before she is entitled to a benefit, are called durational-residence requirements. Durational-residence requirements raise a red flag for many constitutional law scholars because the Supreme Court has struck down many-though not all-of them. It is therefore unsurprising that many lawyers and scholars have argued that durational-residence requirements for in-state tuition are unconstitutional. Nevertheless, no court has found these requirements unconstitutional. Despite that no challenge has succeeded, this Note contends that durational-residence requirements for in-state tuition at public colleges and universities do indeed violate the fundamental right to travel. Part I argues that Saenz\u27s portability distinction is illusory and should not preclude the decision\u27s reasoning from applying to requirements for college tuition. Part II then asserts that because Saenz has moved from a severe-penalties rule to a nondiscrimination rule, courts should apply strict scrutiny in evaluating durational-residence requirements for in-state tuition. Furthermore, this movement undoes the reasoning behind pre-Saenz precedent that declined to apply heightened scrutiny. Finally, Part III argues that these requirements should fail strict scrutiny because either the state interests are not compelling or the means are not narrowly tailored to those interests

    Reducing the Effects of Unequal Number of Games on Rankings

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    Ranking is an important mathematical process in a variety of contexts such as information retrieval, sports and business. Sports ranking methods can be applied both in and beyond the context of athletics. In both settings, once the concept of a game has been defined, teams (or individuals) accumulate wins, losses, and ties, which are then factored into the ranking computation. Many settings involve an unequal number of games between competitors. This paper demonstrates how to adapt two sports rankings methods, the Colley and Massey ranking methods, to settings where an unequal number of games are played between the teams. In such settings, the standard derivations of the methods can produce nonsensical rankings. This paper introduces the idea of including a super-user into the rankings and considers the effect of this fictitious player on the ratings. We apply such techniques to rank batters and pitchers in Major League baseball, professional tennis players, and participants in a free online social game. The ideas introduced in this paper can further the scope that such methods are applied and the depth of insight they offer

    Neutron Transfer Studied with a Radioactive beam of 24Ne, using TIARA at SPIRAL

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    A general experimental technique for high resolution studies of nucleon transfer reactions using radioactive beams is briefly described, together with the first new physics results that have been obtained with the new TIARA array. These first results from TIARA are for the reaction 24Ne(d,p)25Ne, studied in inverse kinematics with a pure radioactive beam of 100,000 pps from the SPIRAL facility at GANIL. The reaction probes the energies of neutron orbitals relevant to very neutron rich nuclei in this mass region and the results highlight the emergence of the N=16 magic number for neutrons and the associated disappearance of the N=20 neutron magic number for the very neutron rich neon isotopes.Comment: Proceedings of the Carpathian Summer School of Physics, Mamaia-Constanta, Romania, 13-24 June 200

    Long-distance Propagation of 162 MHz Shipping Information Links Associated with Sporadic E

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    This is a study of anomalous long-distance (\u3e1000 km) radio propagation that was identified in United States Coast Guard monitors of automatic identification system (AIS) shipping transmissions at 162 MHz. Our results indicate this long-distance propagation is caused by dense sporadic E layers in the daytime ionosphere, which were observed by nearby ionosondes at the same time. This finding is surprising because it indicates these sporadic E layers may be far more dense than previously thought

    A micropillar for cavity optomechanics

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    We present a new micromechanical resonator designed for cavity optomechanics. We have used a micropillar geometry to obtain a high-frequency mechanical resonance with a low effective mass and a very high quality factor. We have coated a 60-Ό\mum diameter low-loss dielectric mirror on top of the pillar and are planning to use this micromirror as part of a high-finesse Fabry-Perot cavity, to laser cool the resonator down to its quantum ground state and to monitor its quantum position fluctuations by quantum-limited optical interferometry

    High-precision measurement of the half-life of 62^{62}Ga

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    The beta-decay half-life of 62Ga has been studied with high precision using on-line mass separated samples. The decay of 62Ga which is dominated by a 0+ to 0+ transition to the ground state of 62Zn yields a half-life of T_{1/2} = 116.19(4) ms. This result is more precise than any previous measurement by about a factor of four or more. The present value is in agreement with older literature values, but slightly disagrees with a recent measurement. We determine an error weighted average value of all experimental half-lives of 116.18(4) ms.Comment: 9 pages, 5 figures, accepted for publication in PR
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