Linewidth characteristics of Raman-shifted dye laser output at 720 and 940 nm

Existing DIAL systems for water vapor measurements in the troposphere operate at wavelengths near 720 nm. The use of stronger water vapor absorption lines in the range 930 to 960 nm will significantly improve DIAL measurements in the upper troposphere and lower stratosphere where water vapor concentrations are low. The generation of light at 940 nm using a frequency doubled Nd:YAG pumped dye laser is inefficient due to the small absorption if infrared dyes at the pump wavelength. However, 940 nm generation utilizing stimulated Raman scattering of dye lasers is attractive because of a potentially high conversion efficiency plus the possibility of retaining the narrow linewidth available from some dye lasers. The Raman conversion efficiency and line broadening are presented for first Stokes operation at 720 and 940 nm using hydrogen and deuterium as the Raman media

President Higdon\u27s 91st Commencement Address

President Lee Higdon told the 2009 graduates You are graduating at a pivotal time in US history – indeed, in the history of the world. In a global economic upheaval, traditional companies and organizations seek to redefine themselves and the work they do. Increasingly, they will look to your generation, and specifically to liberal arts graduates, for answers

President Higdon\u27s 2008 Commencement Address

President Leo I. Higdon, Jr. tells the Class of 2008 that they have impressed him with their intelligence and talents, their compassion and integrity, and their engagement in the world around them through community service in New London and across the world

President Higdon\u27s 94th Commencement Address

President Higdon urges the graduates, Continue to embrace learning in all its forms. Continue to cross boundaries and to make connections that others don’t see. Continue to live the values of the Honor Code and to respect and value equity and inclusiveness as part of your life-long learning

Interstellar turbulence, random density variations, and scintillation measurements

The presence of random electron variations suggests that the ionized interstellar medium is turbulent. In the interstellar plasma the presence of power spectra of such variations extending to spatial scales much less than a Coulomb mean free path, Lambda sub c, is required by analyses of measurements of scintillation and angular broadening of pulsar radio signals. The existence of corresponding variations in magnetic field strength could efficiently scatter cosmic rays and thus constrain cosmic-ray propagation. Unfortunately both the origin of the electron density variations and mechanisms by which these variations couple to fluctuations in magnetic field strength are unknown. It is conjectured that the small-scale density variations are generated by the convective distortion of initially large-scale isobaric entropy structures in the turbulent interstellar plasma. An investigation of the spectra of turbulent entropy structures, velocity, and magnetic fields at small spatial scales is made. The modifier small is employed to characterize length scales much less than the dimension, L, containing the bulk of the turbulent energy

Diffuse galactic annihilation radiation from supernova nucleosynthesis

The propagation of MeV positrons in the outer ejecta of type I supernovae was investigated. It was found that the positrons created at times of approx 100 days propagated along magnetic field lines in the outer ejecta without any appreciable pitch-angle scattering or excitation of hydromagnetic waves. The lack of significant pitch-angle scattering is well consistent with models of wave excitation and scattering by resonant interactions. This occurs because time periods to scatter the particles or to excite waves are significantly longer than escape times. Thus it is expected that, when positrons are not coupled to the ejecta by Coulomb collisions, they escape from the relatively cold, dense ejecta and reside predominantly in the tenuous, hotter, shock-heated interstellar gas. In the tenuous shock-heated gas the positron lifetime against annihilation is much greater than lifetimes in the dense ejectra. Thus the production of steady-state diffuse annihilation radiation by some fraction of these escaped positrons seems probable

Redshifts from Spitzer Spectra for Optically Faint, Radio Selected Infrared Sources

Spectra have been obtained with the Infrared Spectrograph on the Spitzer Space Telescope for 18 optically faint sources (R > 23.9,mag) having f(nu) (24um) > 1.0,mJy and having radio detections at 20 cm to a limit of 115 microJy. Sources are within the Spitzer First Look Survey. Redshifts are determined for 14 sources from strong silicate absorption features (12 sources) or strong PAH emission features (2 sources), with median redshift of 2.1. Results confirm that optically faint sources of ~1 mJy at 24um are typically at redshifts z ~ 2, verifying the high efficiency in selecting high redshift sources based on extreme infrared to optical flux ratio, and indicate that 24um sources which also have radio counterparts are not systematically different than samples chosen only by their infrared to optical flux ratios. Using the parameter q = log[f(nu)(24um)/f(nu)(20 cm)] 17 of the 18 sources observed have values of 0<q<1, in the range expected for starburst-powered sources, but only a few of these show strong PAH emission as expected from starbursts, with the remainder showing absorbed or power-law spectra consistent with an AGN luminosity source. This confirms previous indications that optically faint Spitzer sources with f(nu)(24um) > 1.0mJy are predominately AGN and represent the upper end of the luminosity function of dusty sources at z ~ 2. Based on the characteristics of the sources observed so far, we predict that the nature of sources selected at 24um will change for f(nu)(24um) < 0.5 mJy to sources dominated primarily by starbursts.Comment: Accepted ApJ 20 February 2006, v638 2 issue, 10pages including 3 figure

Polygamous Marriage, Monogamous Divorce

Could the constitutional right to marry also encompass polygamy? That question, which has long intrigued legal scholars, has taken on even greater significance in the wake of Obergefell v. Hodges. This Article answers that question in a novel way by scrutinizing the practice of plural marriage through the lens of economic game theory, exploring the extreme harms that would befall the state should polygamy become law. More specifically, the Article delves into the ex ante consequences of legalization, not on practicing polygamists (as is typically the focus), but on sequential bigamists—that is, those who never intend to have more than one spouse at any given time but who nonetheless marry more than one person in their lifetime. The Article concludes that the state has a compelling economic interest in limiting marriage to two people. If polygamy were to become the law of the land, states could no longer prohibit bigamy. In turn, separating couples would lose one of the strongest incentives they currently have to choose formal divorce proceedings over the seemingly simpler option of mutual desertion: the threat of criminal charges for bigamy. In essence, a sequential bigamist could then marry multiple times in his lifetime without ever divorcing and, at the same time, without risking a criminal charge of bigamy. Such actions—dubbed “sequential polygamy”—would compromise the state’s interest in protecting its citizens from financial harms. After all, divorce proceedings provide the state with an opportunity to intercede into the process, thereby obtaining some assurance that those who are leaving a marriage are not doing so at their financial peril. With the legalization of polygamy, however, bigamy becomes a thing of the past, eroding the state’s ability to encourage divorce as a means of safeguarding the health and safety of its citizens. Most concerning is the impact this change would have on those living in poverty—the people likely to be hardest hit by any societal shift away from formal divorce. Finally, any attempts by the state to distinguish between bigamy and polygamy (for example, by permitting plural marriage but only if all spouses consent), would fail to ameliorate the resulting harm to its citizens

Identifying Catholic School Teachers Attitudes and Perceptions about Death and Grief

Death and grief are not frequently discussed with children as a normal part of life. Previous studies show that teachers are not comfortable discussing the subject in the classrooms. As a trusted source, school nurses are able to help school staff recognize potential signs and symptoms of death and grief with a student dealing with a loss, providing information, educational resources and support. The purpose of this study was to identify the attitudes and perceptions about death and grief of Catholic School teachers working among elementary school age children kindergarten through eighth grades. A convenience sample of 47 teachers from three Catholic schools located in Northern California were approached and participated in the project. Using a Likert type scale, an anonymous survey about death and grief attitudes and perceptions was given to teachers at a regular staff meeting. Results indicated that the teachers were comfortable discussing death and grief with their students, but were not completely confident in locating information about death and grief or integrating it into the classroom curriculum. In order to help children deal more effectively with death and loss, school nurses need to be more aware of how school staff deal with death and grief, and provide support and resources when needed