Electrochemical Behavior of Magnetron-Sputtered Al–Cu Alloy Films in Sulfate Solutions

Model alloys, generated by magnetron sputtering, have been employed to understand the role of copper on the corrosion behavior of aluminum alloys. Binary Al–Cu alloys, with copper contents between 0 and 100 atom %, were synthesized with well-controlled compositions, embracing single-phase alpha and theta alloys together with multiphase alloys. Electrochemical measurements confirmed the stability of the thin alloy films and revealed that the corrosion behavior of the alpha, theta, and eta2 phases differed strongly in the cathodic region. Further, in the anodic region, phases of high copper content suffered pitting in sulfate solutions, while the alpha phase remained passive

The Development Of An Intervention To Increase Cervical Cancer Screening Among Guatemalan Women

Latin American women experience higher rates of cervical cancer, mainly due to lower rates of participation in cervical cancer screening. This study used community-based participatory research to create and implement a tailored lay health worker (LHW) outreach program to increase cervical cancer screening participation in a Guatemalan community. Surveys with Guatemalan women revealed that they would be more likely to participate in screening if they had more information and one of their main sources of information was their peers. An analysis of the existing resources showed that there was not a method of communicating accurate information through the social networks in the community, thus an LHW program met the needs of the community. This paper outlines the implementation of the LHW program in Guatemala and describes its components which may guide future LHW program development to increase cervical cancer screening in Latin America

Going North and West to Watch the Dragons Dance: Norse and Celtic Elements in Ursula Le Guin\u27s Earthsea Trilogy

Sees the world-view of Earthsea, as well as much of the symbolism, characteristic of pre-Christian Nordic and Celtic thought. Focus on present life rather than future is a significant theme

Species-specific patterns in bivalve larval supply to a coastal embayment

Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution February 2011Larval supply is an important process linking reproductive output to recruitment of benthic marine invertebrates. Few species-specific studies of bivalve larvae have been performed due to the lack of suitable methods for species identification. This thesis focused on applying a method to identify larvae from field samples from Waquoit Bay, MA using shell birefringence patterns. This method was then used to address variability in larval supply for three bivalve species on weekly, tidal, and hourly scales. Sampling weekly for six months during two years showed large variability in larval concentrations on this time scale. Abundances of most species were related to bay temperature, and species distributions among sampling sites were indicative of transport potential and population coherence. Greater growth of larvae in 2009 compared to 2007 was attributed to more wind-induced mixing and better food availability in 2009. Integrative samples over each tidal event for a 14-day period demonstrated that larvae were mostly constrained by water masses. During a period when there were sharp tidal signals in temperature and salinity, larval concentrations were higher in bay water compared to coastal waters on incoming tides. After a storm event, water mass properties were less distinct between tidal events and a semidiurnal signal in larval concentrations was no longer apparent. The timing of periods of high larval concentrations did not always coincide with periods of highest water mass flux reducing net export in some cases. On an hourly scale, the vertical distribution of larvae affected by water column stratification and strength of tidal flow. Strong currents and a fresh upper layer both prevented larvae from concentrating at the surface. There was little evidence of peaks in larval concentrations associated with a given tidal period. Species-specific data can provide new perspectives on larval transport. For the three species studied, Anomia simplex, Guekensia demissa, and Mercenaria mercenaria, different source areas, patterns for growth, and potential for export were observed. Applying species-specific identification methods to future studies of bivalve larval transport has the potential to relate larval abundance to settlement patterns, an important component of larval ecology and shellfish management.Funding for this thesis research was provided by an award to from NOAA Sea Grant to S. Gallager (grant NA06OAR417002), an award to S. Gallager and C. Mingione Thompson from the Estuarine Reserves Division, Office of Ocean and Coastal Resource Management, National Ocean Service, National Oceanic and Atmospheric Administration (grant NA07NOS42000024), the WHOI Academic Programs Office, a WHOI Coastal Ocean Institute student grant, the WHOI Biology Department, and the WHOI Ocean Life Institute

Simulating the galvanic coupling between S-Al2CuMg phase particles and the matrix of 2024 aerospace aluminium alloy

Study of the corrosion behaviour of a magnetron sputtered Al–Cu/Al–Cu–Mg model alloy couple in sulphate solutions has been undertaken to gain insight into the galvanic coupling between the matrix and SAl2CuMg particles in the 2024 aluminium alloy (AA2024). Polarisation curves and local electrochemical impedance spectroscopy measurements (LEIS) were performed on the individual alloys and on the model alloy couple. SEM enabled correlation of electrochemical phenomena to the observed damage. The corrosion behaviour of the sputtered alloys was shown to be representative of the AA2024, with the Al–Cu–Mg alloy part undergoing localised corrosion and the Al–Cu alloy part remaining passive