Traffic and nucleation events as main sources of ultrafine particles in high-insolation developed world cities

Road traffic emissions are often considered the main source of ultrafine particles (UFP, diameter smaller than 100 nm) in urban environments. However, recent studies worldwide have shown that - in high-insolation urban regions at least - new particle formation events can also contribute to UFP. In order to quantify such events we systematically studied three cities located in predominantly sunny environments: Barcelona (Spain), Madrid (Spain) and Brisbane (Australia). Three long term datasets (1-2 years) of fine and ultrafine particle number size distributions (measured by SMPS, Scanning Mobility Particle Sizer) were analysed. Compared to total particle number concentrations, aerosol size distributions offer far more information on the type, origin and atmospheric evolution of the particles. By applying k-Means clustering analysis, we categorized the collected aerosol size distributions in three main categories: “Traffic” (prevailing 44-63% of the time), “Nucleation” (14-19%) and “Background pollution and Specific cases” (7-22%). Measurements from Rome (Italy) and Los Angeles (California) were also included to complement the study. The daily variation of the average UFP concentrations for a typical nucleation day at each site revealed a similar pattern for all cities, with three distinct particle bursts. A morning and an evening spike reflected traffic rush hours, whereas a third one at midday showed nucleation events. The photochemically nucleated particles burst lasted 1-4 hours, reaching sizes of 30-40 nm. On average, the occurrence of particle size spectra dominated by nucleation events was 16% of the time, showing the importance of this process as a source of UFP in urban environments exposed to high solar radiation. On average, nucleation events lasting for 2 hours or more occurred on 55% of the days, this extending to >4hrs in 28% of the days, demonstrating that atmospheric conditions in urban environments are not favourable to the growth of photochemically nucleated particles. In summary, although traffic remains the main source of UFP in urban areas, in developed countries with high insolation urban nucleation events are also a main source of UFP. If traffic-related particle concentrations are reduced in the future, nucleation events will likely increase in urban areas, due to the reduced urban condensation sinks.

Effect of nonuniform seismic input on arch dams

Standard earthquake analyses of civil engineering structures use uniform ground motions even though considerable variations in both amplitude and phase can occur along the foundation interface for long-span bridges and large dams. The objective of this thesis is to quantify the effect that these nonuniformities have on the structural response.

The nonuniform, free-field motions of the foundation interface are assumed to be caused by incident plane body waves. The medium in which these waves travel is a linear, elastic half-space containing a canyon of uniform cross section in which the structure is placed. The solutions for the free-field motions that are due to incident SH, P and SV waves are calculated using the boundary element method.

An analysis of Pacoima (arch) dam located near Los Angeles, California, is performed for both uniform and nonuniform excitations. The important effect of nonuniformities in the free-field motions, sometimes leading to a decrease in the dam response and sometimes to an increase, is quantified.

Reunion of Hesperian College alumni, 1951

Reunion of Hesperian College alumni, held on the Chapman College Vermont campus, Los Angeles, California, in 1951.

Charles Clarke Chapman, 1942

Studio portrait of Charles Clarke Chapman, taken by the Edwards-Hostetler studio, Los Angeles, California, 1942. Signed on photo mount "Sincerely Yours, Charles C. Chapman."

Samuel James Chapman, Arthur Chapman, and Anna Chapman, 1905

Portrait of Samuel James Chapman, George Arthur Chapman, and Anna Chapman, about 1905, taken by the Mushet Studio, Los Angeles, California.

Portrait of Ruth Knox Dowling Chapman, 1922

Portrait of Ruth Knox Dowling Chapman, Los Angeles, California, 1922. Wife of George Arthur Chapman, Sr. Signature of photographer hard to read--Yartel Howlett?

Procesos de privatización del agua en América Latina: análisis y seguimiento de la interacción estratégica entre movimientos sociales versus multinacionales en Bolivia, Uruguay y México. Período 2000 – 2006

El presente escrito, constituye una aproximación a los procesos de privatización del agua en América Latina. Lo anterior, en el marco de la acción colectiva, específicamente de los movimientos sociales y su interacción estratégica con oponentes como las compañías multinacionales, las organizaciones financieras internacionales y el Estado. Tomando como referencia las luchas ocurridas en Bolivia, Uruguay y México, con especial énfasis en La Guerra del Agua en Cochabamba (Bolivia).

Burning Skies: A Novella

Burning Skies is a seventy-page novella completed as an Honors Thesis in Creative Writing. The story is set in Los Angeles, California, during the 1992 riots surrounding the controversy over the beating of Rodney King by four white police officers. The story is toldthrough the perspectives of the four main characters: Erin, a woman who is four months pregnant with a baby she desperately wants; her husband David, who has moved the couple out to California so that he can pursue his dream of being a cinematographer; Abby, David’s deeplyreligious younger sister who has unexpectedly flown out to Los Angeles from her home in Indiana after discovering her husband’s infidelity; and Cameron, a black man training to be a pastor who Abby has befriended through her years of missionary work in Los Angeles.The novella follows the events of the riots as they break out all across the city and the personal dramas of each of the four main characters, looking at how the public interacts with theprivate and examining the ways in which explosions in the public and political sphere can ricochet into our private and personal lives. It is a story about the political and racial climate in Los Angeles in the early 1990s, but it is also a story about four human beings, about their needs and their desires, about their struggles to survive in an unpredictable world. The novella showcases the skills and techniques the author has learned after four years of studying fiction at Bucknell University; it can best be described as a work of realistic fiction.

Geriatric Pain Measure short form: development and initial evaluation

OBJECTIVES: To develop and evaluate a short form of the 24-item Geriatric Pain Measure (GPM) for use in community-dwelling older adults. DESIGN: Derivation and validation of a 12-item version of the GPM in a European and an independent U.S. sample of community-dwelling older adults. SETTING: Three community-dwelling sites in London, United Kingdom; Hamburg, Germany; Solothurn, Switzerland; and two ambulatory geriatrics clinics in Los Angeles, California. PARTICIPANTS: European sample: 1,059 community-dwelling older persons from three sites (London, UK; Hamburg, Germany; Solothurn, Switzerland); validation sample: 50 persons from Los Angeles, California, ambulatory geriatric clinics. MEASUREMENTS: Multidimensional questionnaire including self-reported demographic and clinical information. RESULTS: Based on item-to-total scale correlations in the European sample, 11 of 24 GPM items were selected for inclusion in the short form. One additional item (pain-related sleep problems) was included based on clinical relevance. In the validation sample, the Cronbach alpha of GPM-12 was 0.92 (individual subscale range 0.77-0.92), and the Pearson correlation coefficient (r) between GPM-12 and the original GPM was 0.98. The correlation between the GPM-12 and the McGill Pain Questionnaire was 0.63 (P<.001), similar to the correlation between the original GPM and the McGill Pain Questionnaire (Pearson r=0.63; P<.001). Exploratory factor analysis indicated that the GPM-12 covers three subfactors (pain intensity, pain with ambulation, disengagement because of pain). CONCLUSION: The GPM-12 demonstrated good validity and reliability in these European and U.S. populations of older adults. Despite its brevity, the GPM-12 captures the multidimensional nature of pain in three subscales. The self-administered GPM-12 may be useful in the clinical assessment process and management of pain and in pain-related research in older persons.