Enhanced spectral sensitivity of fibre long period gratings to refractive index of aqueous solutions utilising copper patterned coatings

A set of long period grating devices have been fabricated in photosensitive single mode fibre coated with a series of copper rings (period of 380μm, 50% duty cycle and length of 4cm). The long period gratings were inscribed with a uniform UV-laser exposure across the entire length of the copper ring patterned coating. The devices ranged in copper thickness from 0.5μm to 1.5μm. In addition, a control long period grating was fabricated in the same type of fibre with the same period for comparison. The refractive index and temperature spectral sensitivity of these devices were investigated and it was found that the index and temperature sensitivity is a function of the thickness of the copper rings, as supported by theoretical modelling. Furthermore, the index sensitivity of these devices in the 1.333 index region is greater than the control long period grating. The patterned 0.5μm coated long period grating gave a sensitivity of Δλ/Δn = -74 nm leading to a resolution of 1.4×10-3 compared to the control which had a sensitivity of Δλ/Δn = -32 nm with a resolution of 3.2×10-3 in the index region of 1.320 to 1.380 (aqueous solution regime). This demonstrates a two fold increase in the sensitivity. This novel fibre long period grating device shows potential for increasing the resolution of measurements of the index of aqueous solutions.

Mechanisms of a change in the refractive index of an intensely pumped Yb:YAG crystal

Mechanisms of a change in the refractive index appearing in an intensely diode-pumped Yb:YAG-laser disk element are studied with the help of polarisation interferometry and dynamic grating testing. It is found that changes in the electronic component of the refractive index arising upon changing the populations of electronic levels of Yb ions (the ground F state and the upper F level of the laser transition) and caused by the difference in the polarisability of these levels are an order of magnitude greater than thermal changes in the refractive index. It is shown that the difference Δp in the polarisability at the probe wavelength of 633 nm is 1.9 × 10 cm and at the laser transition wavelength of 1029 nm is 1.6 × 10 cm. ©2006 Kvantovaya Elektronika and Turpion Ltd.

A New Method for Computing the Eccentric Connectivity Index of Fullerenes

ACM Computing Classification System (1998): G.2.2, G.2.3.

The role of neighborhood organizations in the production of gentrifiable urban space: The case of Wynwood, Miami's Puerto Rican barrio

Partnerships between government and community-based actors and organizations are considered the hallmark of contemporary governance arrangements for the revitalization and gentrification of economically distressed, inner city areas. This dissertation uses historical, narrative analysis and ethnographic methods to examine the formation, evolution and operation of community-based governance partnerships in the production of gentrifiable urban space in the Wynwood neighborhood of Miami, FL between 1970 and 2010. This research is based on more than four years of participant observation, 60 in-depth interviews with respondents recruited through a purposive snowball sample, review of secondary and archival sources, and descriptive, statistical and GIS analysis. This study examines how different organizations formed in the neighborhood since the 1970s have facilitated the recent gentrification of Wynwood. It reveals specifically how partnerships between neighborhood-based government agencies, nonprofit organizations and real estate developers were constructed to be exclusionary and lead to inequitable economic development outcomes for Wynwood residents. The key factors conditioning these inequalities include both the rationalities of action of the organizations involved and the historical contexts in which their leaders’ thinking and actions were shaped. The historical contexts included the ethnic politics of organizational funding in the 1970s and the “entrepreneurial” turn of community-based economic development and Miami urban politics since the 1980s. Over time neighborhood organizations adopted highly pragmatic rationalities and repertoires of action. By the 2000s when Wynwood experienced unprecedented investment and redevelopment, the pragmatism of community-based organizations led them to become junior partners in governance arrangements and neighborhood activists were unable to directly challenge the inequitable processes and outcomes of gentrification.

delta Deuterium of alkenone and BIT index of sediment core 64PE304-80 samples

Reconstructing past ocean salinity is important for assessing paleoceanographic change and therefore past climatic dynamics. Commonly, sea water salinity reconstruction is based on foraminifera oxygen isotope ratio values combined with sea surface temperature reconstruction. However, the approach relies on multiple proxies, resulting in relatively large uncertainty and, consequently, relatively low accuracy of salinity estimates. An alternative tool for past ocean salinity reconstruction is the hydrogen isotope composition of long chain (C37) alkenones (dDalkenone). Here, we applied dDalkenone to a 39 ka long coastal sediment record from the Eastern South African continental shelf in the Mozambique Channel, close to the Zambezi River mouth. Despite changes in global sea water dD related to glacial - interglacial ice volume effects, no clear changes were observed in the dDalkenone record throughout the entire 39 ka. The BIT index record from the same core showed high BIT values during the glacial and low values during the Holocene. This indicates a more pronounced freshwater influence at the core location during the glacial, resulting in alkenones depleted in deuterium during that time and, thereby, explains the lack of a clear glacial-interglacial alkenone dD shift. Correlation between the BIT index and dDalkenone during the glacial period suggests that increased continental runoff potentially changed the growth conditions of the alkenone producing haptophytes, promoting coastal haptophyte species with generally more enriched dDalkenone values. We therefore suggest that the application of dDalkenone for reconstructing past salinity in coastal settings may be complicated by changes in the alkenone producing haptophyte community.

National Council of Neighborhood Women conference (business women)

General note: Title and date provided by Bettye Lane.

National Council of Neighborhood Women conference (business women)

General note: Title and date provided by Bettye Lane.

Building an index of well-being for children living in Ireland: conceptual, measurement and policy considerations

This study conceptualised and measured children’s well-being in Ireland and considered how such conceptualisations and approaches to the measurement of well-being might inform social policy for children and families living in Ireland. This research explored what is meant by children’s well-being and how it can be conceptualised and measured so as to reflect the multi-dimensionality of the concept. The study developed an index of well-being that was both theoretically and methodologically robust and could be meaningfully used to inform social policy developments for children and their families. For the first time, an index of well-being for children was developed using an explicitly articulated unifying theory of children’s well-being. Moreover, for the first time an index of wellbeing was developed for 13-year old children living in Ireland using data from Wave 2 of the national longitudinal study of children. The Structural Model of Child Well-being (SMCW), the theoretical framework that underpins the development of this study’s index, offers a comprehensive understanding of well-being. The SMCW builds on, and integrates, a range of already-established theories concerning children’s development, their agency, rights and capabilities into a unifying theory that explains well-being in its entirety. This conceptualisation of well-being moves beyond the narrow focus on child development adopted in some recent studies of children’s well-being and which perpetuate individualised and self-responsibilising conceptualisations of well-being. This study found that the SMCW can be meaningfully applied, both theoretically and operationally, to the construction of an index of well-being for children. While it was not the purpose of this study to validate the SMCW, in the process of developing the index, I concluded that there was a theoretical ‘fit’ between the conceptual orientation of the SMCW and the wider children’s well-being literature. The ‘nested’ structure of the SMCW facilitated the identification of domains, sub-domains and indicators of well-being reflecting typical conventions of index construction. The findings from the resulting index, in both its categorical and continuous forms, demonstrated how a comprehensive theory of well-being can be used to illustrate how children are faring and which children are experiencing poorer or better well-being. Furthermore, this study demonstrated how the SMCW and the resultant index can be meaningfully used to support the implementation and review of the national policy framework for children and young people in Ireland.

Dissolution index of Globigerina bulloides in recent and Last Glacial Maximum sediments

The modern Atlantic Ocean, dominated by the interactions of North Atlantic Deep Water (NADW) and Antarctic Bottom Water (AABW), plays a key role in redistributing heat from the Southern to the Northern Hemisphere. In order to reconstruct the evolution of the relative importance of these two water masses, the NADW/AABW transition, reflected by the calcite lysocline, was investigated by the Globigerina bulloides dissolution index (BDX?). The depth level of the Late Glacial Maximum (LGM) calcite lysocline was elevated by several hundred metres, indicating a more corrosive water mass present at modern NADW level. Overall, the small range of BDX? data and the gradual decrease in preservation below the calcite lysocline point to a less stratified Atlantic Ocean during the LGM. Similar preservation patterns in the West and East Atlantic demonstrate that the modern west-east asymmetry did not exist due to an expansion of southern deep waters compensating for the decrease in NADW formation.

Stable isotope record and aklenonen index of MIS 11 sediments

The interglacial known as Marine Isotope Stage 11 has been proposed to be analogous to the Holocene, owing to similarities in the amplitudes of orbital forcing. It has been difficult to compare the periods, however, because of the long duration of Stage 11 and a lack of detailed knowledge of any extreme climate events that may have occurred. Here we use the distinctive phasing between seasurface temperatures and the oxygen-isotope records of benthic foraminifera in the southeast Atlantic Ocean to stratigraphically align the Holocene interglacial with the first half of the Marine Isotope Stage 11 interglacial optimum. This alignment suggests that the second half of Marine Isotope Stage 11 should not be used as a reference for 'pre-anthropogenic' greenhouse-gas emissions. By compiling benthic carbon-isotope records from sites in the Atlantic Ocean on a single timescale, we also find that meridional overturning circulation strengthened about 415,000 years ago, at a time of high orbital obliquity. We propose that this mechanism transported heat to the high northern latitudes, inhibiting significant ice-sheet build-up and prolonging interglacial conditions. We suggest that this mechanism may have also prolonged other interglacial periods throughout the past 800,000 years.

G. bulloides dissolution index of surface sediments

The Atlantic is regarded as a huge carbonate depocenter due to an on average deep calcite lysocline. However, calculations and models that attribute the calcite lysocline to the critical undersaturation depth (hydrographic or chemical lysocline) and not to the depth at which significant calcium carbonate dissolution is observed (sedimentary calcite lysocline) strongly overestimate the preservation potential of calcareous deep-sea sediments. Significant calcium carbonate dissolution is expected to begin firstly below 5000 m in the deep Guinea and Angola Basin and below 4400 m in the Cape Basin. Our study that is based on different calcium carbonate dissolution stages of the planktic foraminifera Globigerina bulloides clearly shows that it starts between 400 and 1600 m shallower depending on the different hydrographic settings of the South Atlantic Ocean. In particular, coastal areas are severely affected by increased supply of organic matter and the resultant production of metabolic CO2 which seems to create microenvironments favorable for dissolution of calcite well above the hydrographic lysocline.