PRECIOUS MANGROVE: AN ETHNOGRAPHY OF ENVIRONMENTAL RESILIENCE

The Seri indigenous people of Mexico have been living in the desert along the Sea of Cortés for thousands of years. Their territory includes the northern most mixed mangrove estuary in Mexico. After reviewing previous literature about the Seri and the estuary, I developed a set of questions and visited their villages for interviews and a field trip. The interview topics included how their family groups are defined, what the name was of the group that used to live near the estuary, the status of who is allowed to perform songs and explain traditions, and what environmental changes they have seen at the estuary. Theories about the connection between oral history, oral tradition, and historical events, provided a framework to examine what they told me. To provide another view of this estuary, I created a Normalized Data Vegetation Index using satellite imagery from the years 2000 to 2018 that provides information about the mangrove vegetation. Instead of only being research subjects, the communities in which anthropologists engage can be considered partners. Since some of the Seri are trained paraecologists, this vegetation index will be presented to them to help in their environmental observations

Green aromatics for a bio-based economy - Valorization of biomass derived model compounds over zeolites studied by online analysis

In the strive towards sustainable chemical production, its carbon-based products can no longer be produced from fossil resources but need to be manufactured from a renewable feedstock. Simple aromatic building blocks like benzene, toluene and xylenes (BTX) can be obtained by catalytic valorization of biomass derived platform molecules such as furans provided efficient catalysts can be formulated. To evaluate catalysts for the conversion of furans to BTX and study the involved catalytic reactions, advanced analytical methods are needed. The observation of dynamic responses in catalytic activity and selectivity necessitates time-resolved analysis of rather complex hydrocarbon (HC) streams. In this work, an online analysis method combining Fourier transform infrared spectroscopy and ion molecule reaction mass spectrometry has been developed for the direct monitoring of the effluent stream during conversion of furans over zeolite catalysts. The sampling frequency is shown to be at least 4 per minute, which is considerably higher compared to that of separation-based methods operating on time scales of several minutes. A wide range of HCs and other smaller molecules is identified and individual species quantified simultaneously. The carbon balance of around 90% shows that the vast majority of the complex HC stream is indeed analysed. The developed online analysis has been applied to catalytic step-response experiments, where different zeolites were exposed to concentration steps of 2,5-dimethylfuran at steady temperatures. It is found that the HC stream consists of a range of olefins and aromatics, including BTX. Most interestingly, 2,5-dimethylfuran is isomerized to 2,4-dimethylfuran as well as 2- and 3-methyl-2-cyclopenten-1-one. The formation of BTX is linked to the availability of olefins, which is supported by temperature programmed desorption experiments.Furthermore, to build understanding of the catalytic mechanisms, surface species were characterised in situ by use of diffuse reflectance infrared Fourier transform spectroscopy. It is clear that upon adsorption, 2,5-dimethylfuran interacts with the zeolite structure and undergoes transforming reactions to olefins and aromatics upon temperature increase, but further studies are necessary to comprehend how the rather low selectivity towards BTX can be increased by catalyst design

Green Aromatics: Catalytic Valorisation of bio-derived 2,5-dimethylfuran over Zeolites and Zeotypes

This thesis discusses the use of biomass as a potentially green feedstock for the chemical industry in the urgent shift away from fossil resources. I elaborate on reasons why we cannot afford to burn virgin biomass for energy production, among them a variety of ecosystem services that forests and other lands provide. In addition, the utilisation of biomass should be focused on products that sequester and lock away carbon for more extended periods, e.g. timber, materials and chemicals. In particular, biomass can be used as an alternative "carbon neutral" feedstock for the chemical industry, where we can preserve the already existing chemical complexity in the bio-based molecules. One example is the upgrading of furans to benzene, toluene and xylene (BTX) aromatics with the help of zeolite catalysis. These aromatics are important commodity chemicals, where the shift to a bio-based resource could make use of already existing knowledge, catalyst and production infrastructure. However, research is necessary to understand these new feedstock molecules and their interaction with the catalysts and to enable the design of applicable catalysts.In order to study the interaction of the furans, in particular 2,5-dimethylfuran (2,5-dmf), I describe and discuss the development of an analytical methodology that utilises infrared spectroscopy and mass spectrometry for the on-line identification and quantification of product molecules during catalytic reactions.This on-line analysis method is then applied to the catalytic conversion of 2,5-dmf to aromatics over a range of zeolite and zeotype catalysts. In-depth studies with ammonia as a probe molecule of the catalytic active acid sites, as well as temperature programmed experiments with ammonia and 2,5-dmf give insights into product distribution, selectivity changes and deactivation of the catalyst. For example, olefins and aromatics are initially preferred products, while with increasing time on stream, the isomerisation of 2,5-dmf becomes dominant. The incorporation of Ga into the zeotype framework, resulting in a Ga-Silicate, shows how targeted catalyst design can increase overall aromatics production. This catalyst is also suitable for selective isomerisation of 2,5-dmf to 2,4-dimethylfuran, which has a rare substitution pattern. Finally, itwas found that the most valuable of BTX,\ua0p-xylene, can be produced more selectively when 2,5-dmf is pre-adsorbed onto zeolite ZSM-5 and then released during a temperature programmed product desorption

Extracorporeal Membrane Oxygenation (ecmo) In Adults In The United States From 2006-2011

Objective: Recent studies have shown the benefits of extracorporeal membrane oxygenation (ECMO) in supporting adults with severe respiratory or cardiac failure refractory to conventional treatments. The purpose of this investigation was to analyze the utilization of ECMO in adults to identify recent trends within the United States. Methods: In a serial cross-sectional study, the utilization rate of ECMO in adults in the United States from 2006 to 2011, as well as the survival rates and costs of hospitalization were analyzed using the Nationwide Inpatient Sample (NIS) from the Healthcare Cost and Utilization Project (HCUP). The survival rates were further analyzed by grouping the hospitals by size, type, or volume of adult ECMO cases. Results: The rate of ECMO cases per million adult discharges increased 433% from 11.4 (95% CI, 6.1-16.8) in 2006 to 60.9 (95% CI, 28.1-93.7) in 2011 (p for trend = 0.001). Throughout this six-year period, there were no statistically significant changes in the survival rates (p for trend = 0.14), costs per day (p for trend = 0.07), or total costs per patient (p for trend = 0.87). Hospitals that were small, nonteaching, or had few adult ECMO cases were more likely to transfer their patients to other acute care hospitals. Conclusion: From 2006 to 2011, there was a huge increase in the utilization of ECMO in adults with no significant changes in survival rates or hospitalization costs. ECMO as a therapeutic modality should be given consideration in critically ill patients with reversible cardio-respiratory collapse

Panel 14 Is What We Know About Top Management Support Practically Useful? A Challenge to the Conventional Wisdom

The conventional wisdom deriving from practice is that top management support is an unmitigated good for IS projects — so good, in fact, that the textbooks and research literature do not say what constitutes top management support, what function it serves, or how to obtain it