- K75000 Service Groups (x)
- Search results
Search results
Show moreThe first hyperpolarizability of several Λ-like chromophores including Malachite Green and Brilliant Green were measured by means of Kleinman-disallowed hyper-Rayleigh (harmonic light) scattering (KD-HRS). Such chromophores are of interest as components of a new class of chiral and axial macroscopic materials. Light scattering measurements were carried out in both the non-resonant and the anomalous dispersion regime in order to compare experimental results with a two-level model that indicates that B-symmetry excited states will contribute. Large hyperpolarizabilities were observed in all cases and evidence that the lowest-lying excited state has B-symmetry was found in some molecules. © 2001 Elsevier Science B.V.
Show less
Show moreThe interactions of 604 MeV π- mesons in a hydrogen bubble chamber have been systematically analyzed. In 33 000 pictures a total of 8052 usable events were found, corresponding to cross sections of 18.9±1.3 mb for σ(elastic), 4.98±0.54 mb for σ(π-pπ0), 7.87±0.91 mb for σ(π-nπ+), 14.0±1.0 mb for σ(neutrals), with σ(two-pion production)<0.2 mb, for a total cross section of 45.9±1.9 mb at this energy. The angular distribution for elastic scattering was fitted with a fifth-order polynomial in cosθ which gave a value of dσ/dΩ(0°) consistent with dispersion theory. The pion-pion effective-mass distributions for both single-pion-production channels showed pronounced peaking at high mass values, strongly inconsistent with simple isobar-production kinematics. Simple one-pion exchange does not appear to play a significant role.
http://link.aps.org/doi/10.1103/PhysRev.135.B232
Phys. Rev. 135, B232–B240 (1964)
Show less
Show moreTotal cross sections, angular, and mass distributions for the reaction π-p→π0π0n have been measured for pπ-(lab)=7–140 MeV/c above threshold. The threshold amplitude was used to determine a value for the chiral-symmetry-breaking parameter, ξ, of -0.98±0.52. The ππ scattering lengths aI for isospin I=0 and 2 are derived from this result, together with a current-algebra sum rule. The results are a0=(0.207±0.028)mπ-1 and a2=(-0.022±0.011)mπ-1. These values are consistent with chiral symmetry broken by the Weinberg ππ interaction and the effects of the f0(975) scalar meson.
Phys. Rev. C 44, 956–965 (1991)
http://link.aps.org/doi/10.1103/PhysRevC.44.956
Show less
Show moreππ scattering amplitudes have been determined in the energy range 0.6 to 1.42 GeV. The amplitudes have been extracted in the framework of an absorption-modified one-pion-exchange model with certain energy-dependent assumptions.
Phys. Rev. D 10, 2070–2079 (1974)
http://link.aps.org/doi/10.1103/PhysRevD.10.2070
Show less
Show morePublic policies supporting market-oriented strategies to develop mixed-income communities have become ascendant in the United States and a number of other countries around the world. Although framed as addressing both market goals of revitalization and social goals of poverty deconcentration and inclusion, these efforts at ‘positive gentrification’ also generate a set of fundamental tensions — between integration and exclusion, use value and exchange value, appropriation and control, poverty and development — that play out in particular concrete ways on the ground. Drawing on social control theory and the ‘right to the city’ framework of Henri Lefebvre, this article interrogates these tensions as they become manifest in three mixed-income communities being developed to replace public housing complexes in Chicago, focusing particularly on responses to competing expectations regarding the use of space and appropriate normative behavior, and to the negotiation of these expectations in the context of arguments about safety, order, what constitutes ‘public’ space, and the nature and extent of rights to use that space in daily life.
Show less
Show moreHealthcare workers have been on the front lines throughout the COVID-19 pandemic, treating affected patients and navigating overwhelmed healthcare systems. Emotional connection has been associated with resilient outcomes following collective trauma. This qualitative study examined how healthcare workers define emotional connectedness during the COVID-19 pandemic and their adaptive emotional connection strategies. Data were gathered through the first wave of the online COVID-19 Pandemic and Emotional Well-Being study, a prospective panel study of the psychological impact of COVID-19 on frontline workers and the general public. This study focused on three extended-response questions about definitions of and strategies for emotional connectedness. Data were analyzed using reflexive thematic analysis. Participants conceptualize emotional connectedness as having empathy and value, help and support, presence, and vulnerability. They also describe emotionally connected relationships as being characterized by mutuality and frequent contact. Participants identify current behavioral strategies for cultivating emotional connectedness, such as using technology, providing instrumental help or sending gifts via mail, and building quality time within their households. They also report challenges in maintaining these connections. Future research must contribute knowledge about effective interventions for essential healthcare workers in the aftermath of COVID-19. Specific recommendations for social work practitioners are also discussed.
Show less
Show moreNonprofit leaders are frequently passionate about their organizations, many having devoted their lives and sacrificed significant material benefits for the sake of their causes. Often, though, this intense devotion unconsciously engenders an attitude of ownership towards their organizations (“This is my cause,” “I know best,” “No one else could possibly care/know/do as much as I do.”), rather than an attitude of stewardship (“We must welcome the best and all work in partnership together to address this great cause, and see that it continues addressing this need long after we are gone.”). This ethnographic study examined one nonprofit organization that espoused and essentially practiced the value of stewardship, to discover the attributes that created and perpetuated that culture. We uncovered critical organizational/systemic and personal/leadership traits that stimulate or obstruct stewardship in nonprofit organizations, which inform both governance and human resource practice.
Doctorate of Management Programs
Show less