Dissertations / Theses on the topic 'Seep gas'

Thesis (Ph. D.)--University of North Carolina at Chapel Hill, 2007.
Title from electronic title page (viewed Dec. 18, 2007). "... in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Department of Marine Sciences." Discipline: Marine Sciences; Department/School: Marine Sciences.

A deep-sea time-lapse camera and several temperature probes were deployed on the Gulf of Mexico continental shelf at a biological community associated with a gas hydrate outcropping to study topographic and hydrologic changes over time. The deployment site, Bush Hill (GC 185), is located at 27°47.5' N and 91°15.0' W at depths of ~540m. The digital camera recorded one still image every six hours for three months in 2001, every two hours for the month of June 2002 and every six hours for the month of July 2002. Temperature probes were in place at the site for the entire experimental period. The data recovered provide a record of processes that occur at gas hydrate mounds. Biological activity was documented by identifying the fauna observed in the time-lapse record and recording the number of individuals and species in each image. 1,381 individual organisms representing 16 species were observed. Sediment resuspension and redistribution were regular occurrences during the deployment periods. By digitally analyzing the luminosity of the water column above the mound and plotting the results over time, the turbidity at the site was quantified. A significant diurnal pattern can be seen in both luminosity and temperature records, indicating a possible tidal or inertial component to deep-sea currents in this area. Contrary to expectations, there was no major change in shape or size of the gas hydrate outcrop at this site on the time frame of this study. This indicates that this particular mound was more stable than suggested by laboratory studies and prior in situ observations. The stable topography of the gas hydrate mound combined with high bacterial activity and sediment turnover appears to focus benthic predatory activity in the mound area. The frequency and recurrence of sediment resuspension indicates that short-term change in the depth and distribution of surface sediments is a feature of the benthos at the site. Because the sediment interface is a critical environment for hydrocarbon oxidation and chemosynthesis, short-term variability and heterogeneity may be important characteristics of these settings.

Thesis (Ph. D.)--School of Biology, Georgia Institute of Technology, 2005. Directed by Patricia Sobecky.
Frank Loeffler, Committee Member ; Roger Wartell, Committee Member ; Joseph Montoya, Committee Member ; Thomas DiChristina, Committee Member ; Patricia Sobecky, Committee Chair. Vita. Includes bibliographical references.

Saline aquifers and depleted hydrocarbon fields situated beneath the North Sea are currently being proposed as storage repositories for anthropogenic CO2 captured from point source emitters in the UK and mainland Europe. Two experimental sites are already operating successfully offshore Norway: Sleipner since 1996 and Snøhvit since 2007, collectively storing several million tonnes of CO2/year in the sub-surface. Despite the apparent success of these current projects, one of the major public and scientific concerns is the ability of storage sites to retain CO2 on the millennial timescales required for CO2 plume stabilisation and dissolution. Some areas of the North Sea are also known to contain palaeo-gas seepage pathways within overburden sediments that overlie deeper hydrocarbon reservoirs (e.g. Witch Ground Graben). These areas either need to be avoided for CO2 storage or rigorously assessed in terms of leakage risk. Since the Sleipner storage site lies within such a province, this thesis delivers a detailed evaluation of the Nordland Group overburden and a critical assessment of its long-term sealing capability for CO2. From interpretation and detailed mapping of a baseline 3D seismic dataset (acquired before CO2 injection operations commenced in 1996), we have identified numerous palaeo-migration pathways and high-amplitude seismic anomalies within the Nordland Group overburden sediments deposited above the Sleipner CO2 storage site. We attributed these features to thermogenic or biogenic gas migration, accumulation and bio-degradation over geological time. We also mapped a complex network of sand-filled, glacial channels and tunnel valleys distributed within a few hundred metres below seabed and highlighted their significance as potential fluid migration networks and/or secondary storage containment for leaking CO2. Of further significance, we confirmed that these overburden features also create spatial density variations that impact on the accuracy of seismic time-depth conversions, resulting in the probability of topographic distortions being propagated into seismic interpretations and models. To the best of our knowledge no such detailed mapping of the Nordland Group overburden at Sleipner has been undertaken previously. To determine whether the top layer of the CO2 plume at Sleipner might encounter these relict pathways as it ascends and migrates laterally beneath the caprock, we evaluated the critical column heights required for a CO2 accumulation to enter such a pathway under a range of storage conditions for a CH4/CO2/brine system; assuming that these pathways currently contain methane gas. Risking scenarios were based on a range of phase saturation, pressure, temperature, density, viscosity, interfacial tension and wettability conditions likely to be encountered at depths commensurate with the caprock at Sleipner. We concluded that given certain conditions at the caprock, CO2 could leak more easily into palaeo-migration pathways than CH4 (i.e. at lower entry pressures and therefore smaller column heights), assuming that brine densities and, most importantly, pore radii have not changed significantly over geological time (i.e. no cementation or dissolution has taken place). To further understand the dynamic significance of these palaeo-migration pathways, channels and tunnel valleys, including their ability to form inter-connected leakage/migration networks, we constructed a series of high-resolution 3D models of the Sleipner storage site and overburden, then used stochastic basin modelling and simulation techniques to investigate the processes involved during the introduction of CO2 into the storage site over a prolonged time period. Models were populated with geological, stratigraphic and structural information derived from our seismic interpretation. Flow simulations were calibrated to published data and matched to the present-day plume distribution. The absence of observational reservoir pressure and temperature data from Sleipner introduces significant uncertainty to model outcomes with respect to CO2 density and column height estimates and to surmount this difficulty we constrained the caprock temperature to CO2 density estimates obtained from the most recent gravity data observations at Sleipner. We concluded that the overburden heterogeneity is significant and palaeo-migration pathways, highpermeability channels and tunnel valleys at Sleipner may become potential migration pathways for CO2 as the plume continues to spread laterally over the coming decade, but the possible storage response is difficult to quantify given the absence of sufficient overburden rock property information and accurate pressure and temperature data for the storage site. The overall conclusion from this work is that insufficient information was collected within the Sleipner area prior to storage site development and too many significant studies which should have been performed as a pre-requisite (e.g. obtaining a caprock sample for laboratory testing of potential seal capacity), were actually performed some years after CO2 injection operations had already commenced. The pressure and temperature conditions at the caprock depth for the Sleipner storage site are also marginal in terms of maintaining CO2 above critical point conditions in dense phase and thus maximising storage efficiency. Most significantly, no rigorous overburden mapping and risking was performed for Sleipner (such as the work described in this thesis), thus the fact that no leakage has been detected at Sleipner is more due to good fortune than following best practices. Hopefully, our work has highlighted these key deficiencies so that future CO2 storage site feasibility and development studies will be performed more diligently.

L’existence de fluides géologiques riches en hydrogène (H2) doit nécessairement faire l’objet de travaux d’exploration afin de statuer sur le potentiel énergétique de cette éventuelle ressource décarbonée. Depuis plus d’un siècle de nombreuses exhalations naturelles d’H2 ont été mis en évidence. Or à ce jour il n’existe aucun guide d’exploration basé sur une méthodologie et sur des indicateurs robustes. La détection d’occurrence gazeuse en surface correspond bien évidemment à l’approche la plus efficace et la plus rapide à mettre en œuvre pour identifier des flux. Il n’en reste pas moins qu’un flux ne constitue pas une ressource pour autant, puisqu’à ce jour, l’homme n’exploite que les stocks de ressources énergétiques fossiles. Il sera donc important de développer un guide d’exploration non pas orienté uniquement sur une problématique de surface, mais aussi sur des considérations géologiques profondes intégrant le système hydrogène dans son entier de la source au piège ou à la fuite dans l’atmosphère.Au cours de ce travail de thèse nous proposons d’utiliser le cadre géologique du piémont nord Pyrénéen pour élaborer un guide d’exploration. La compilation des données bibliographiques a révélé un contexte prometteur pour un système H2 du fait d’un lien entre sources profondes, chemins de migration crustale, dynamique de circulation de fluides, et pièges sédimentaires. En effet le nord-ouest des Pyrénées et plus particulièrement le Bassin Mauléon est caractérisé par la présence i) d’un corps mantellique (<10 km) où les conditions pression-température sont favorables à la serpentinisation ; ii) d’accidents structuraux majeurs tels que le Chevauchement Frontal Nord Pyrénéens (CFNP) constituant des drains collecteurs de grande ampleur, iii) des gradients hydrauliques, conjugués à des gradients de température et de pressions qui permettent la mise en mouvement des fluides ; iv) des formations sédimentaires imperméables ou de couvertures comme les évaporites ou les argiles consitutant des pièges pour accumuler l’H2.Suite à cette étude préalable, nous avons mis en place une campagne d’analyses des gaz du sol (H2, CO2, 222Rn, O2, CH4) à l’échelle régionales. Cette campagne d’analyse réalisée sur plus de 7500 km2 a très vite permis de mettre en évidence une zone à très fortes anomalies en H2, CO2, et 222Rn sur le pourtour du Bassin de Mauléon. Cette découverte nous a permis de resserrer rapidement le maillage de prospection sur la partie nord du bassin de Mauléon. Une campagne d’analyses géochimiques et géophysiques a été réalisée à Sauveterre-de-Béarn afin de déterminer l’origine et le parcours des gaz à l’origine de cette anomalie. Sur la base de l'analyse des gaz du sol et des levés électromagnétiques, nous avons confirmé l'existence d'une faille drainant les fluides profonds. De plus, l’étude des données historiques des forages entrepris dans la région il y a plus de 50 ans, conjugué à une mise en perspective des dernières connaissances géologiques et géophysiques de la région, nous a permis de mettre en évidence des zones où l’H2 pourrait s’accumuler.Enfin une partie expérimentale de broyage de quartz et de roches de la région a été menée afin d’explorer de nouveaux mécanismes de production d’H2 le long des failles. Nous avons mis en évidence une très forte influence du rapport eau/roche (W/R) et du pH sur la production d’H2. Ces découvertes apportent un éclairage nouveau sur les mécanismes mécano-radicalaires de production d’H2 où la spéciation des sites des surface des minéraux sont des paramètres clés contrôlant la production d’H2. Nous révélons pour la première fois que le broyage du quartz en présence de solutions carbonatés induit la formation d’espèces carboxylates (formate, acétate, oxalate). En plus de produire de l’H2, les mécanismes mécano-radicalaires permettent donc de produire des espèces réduites du carbones pouvant constituer une source d’énergie pour les écosystèmes microbiens lithotrophe de subsurface
The existence of geological fluids rich in hydrogen (H2) rise the question about the energy potential of this carbon-free resource. For more than a century and throughout the world, numerous natural H2 seepages have been discovered. However, to date there is no exploration approach based on robust methodologies and pathfinders. The detection of H2 seepages at the surface is known to be the most ecient and straight forward approach to identify H2 flows. However, a gas flow does not necessarily constitute a resource, since to date, mankind only exploit reservoirs of fossil energy resources. Therefore, it is important to develop an exploration guide that is not only focusing on surface gas monitoring, but also considering a deep geological approach integrating the entire hydrogen system from source to trap or leakage into the atmosphere. Here, we propose to use the geological framework of the North Pyrenean foothills as a case study to develop this exploration guide. A literature review of the area revealed a promising geological setting for a H2 system due to a strong link between putative deep H2 sources, crustal-scale migration pathways, fluid circulation dynamics, and sedimentary traps. Indeed, the northwestern Pyrenees and particularly the Maul´eon Basin is characterised by the presence of i) an ultramafic mantle body located less than 10 km depth and under pressure-temperature conditions favourable to serpentinisation ; ii) major faults such as the North Pyrenean Frontal Thrust (NPFT) constituting large-scale flow convergence and drainage, iii) hydraulic gradients due to the presence of strong reliefs, combined with temperature and pressure gradients that trigger fluids ; iv) impermeable sedimentary formations or caprocks such as evaporites or claystones overlying porous reservoir rocks that can constitute traps for accumulating H2.Following this preliminary geological survey, we set up a soil gas exploration campaign (H2, CO2, 222Rn, O2, CH4) at the regional scale. These field measurments, carried out over more than 7,500 km2, revealed several hotspots with very high H2, CO2 and 222Rn concentrations anomalies around the Maul´eon Basin. This discovery allowed us to refine the mesh of the prospecting grid to the northern part of the Maul´eon Basin around the locality of Sauveterre-de-Béarn. Geochemical and geophysical measurements were carried out at Sauveterre-de-B´earn to determine the source and migration path of the gases at the origin of this anomaly. Based on soil gas analysis and electromagnetic surveys, we confirmed the existence of a fault draining deep fluids. In addition, the study of historical data from drilling carried out in the region more than fifty years ago, combined with the latest geological and geophysical knowledge of the region, enabled us to highlight zones where H2 could accumulate.Finally, an experimental part of comminution of quartz and rocks from the region was carried out in order to explore the reaction mechanisms of H2 production in active fault zones. We reveal the very strong influence of the water/rock ratio (W/R) and pH on H2 production. These findings shed new light on the mechano-radical mechanisms of H2 production where the efficiency of grinding as well as the speciation of mineral surface sites are key parameters controlling H2 production. We reveal for the first time that grinding of quartz in the presence of carbonate solutions induces the formation of carboxylate species (formate, acetate, oxalate). In addition to producing H2, the mechano-radical mechanisms thus allow the production of reduced carbon species that can constitute an energy source for subsurface lithotrophic microbial ecosystems

An extensive experimental programme tested an l-SEP unit with air and water. This provided data on the separation efficiency and pressure drop across the l- SEP, as they varied with changing inlet conditions, geometry and outlet restrictions. The main conclusion from this work is that the resistance on the outlets directly affects the efficiency of the separator. Although it is possible to optimise the performance by changing 'the geometry, a small change in inlet conditions, common in oil and gas applications, causes the performance to change. _By using an identified relationship between the differential pressure and the operating conditions, an optimum performance over a much wider range of inlet conditions can be achieved. This work has contributed to the field of gas/liquid separation in axial-flow cyclones by demonstrating that manipulating the differential pressure between the outlets can control the separation efficiency. The relationship developed between the optimum differential pressure and the inlet conditions has not been identified in any of the literature available at the time of this work.

An extensive experimental programme tested an l-SEP unit with air and water. This provided data on the separation efficiency and pressure drop across the l- SEP, as they varied with changing inlet conditions, geometry and outlet restrictions. The main conclusion from this work is that the resistance on the outlets directly affects the efficiency of the separator. Although it is possible to optimise the performance by changing 'the geometry, a small change in inlet conditions, common in oil and gas applications, causes the performance to change. _By using an identified relationship between the differential pressure and the operating conditions, an optimum performance over a much wider range of inlet conditions can be achieved. This work has contributed to the field of gas/liquid separation in axial-flow cyclones by demonstrating that manipulating the differential pressure between the outlets can control the separation efficiency. The relationship developed between the optimum differential pressure and the inlet conditions has not been identified in any of the literature available at the time of this work.

Increasing energy demand, coupled with the recent emphasis on domestic production, has resulted in an increase in natural gas exploration and pipeline construction in the central Appalachian region. Very little is known about the effects of natural gas pipeline construction on sediment production. The goals of this project were to measure erosion and examine the effects of vegetation and precipitation characteristics on erosion on a newly constructed pipeline in the Fernow Experimental Forest in West Virginia. The study explored whether seed rate, slope class, or aspect, influenced erosion. The cross country pipeline was buried beneath the surface on study hillslopes ranging from 30-68% and beneath a less steep segment with slopes ranging from 18-26%. A mixture of native herbaceous-plant seeds and straw mulch were applied following construction. Two different seeding rates were applied to compare vegetative recovery and to determine if increasing the seed rate would decrease erosion. A 1-time seed rate, or the normal Forest Service application rate, and a 3-time seed rate (1-time + twice that rate) were tested. Two aspects (northwest-facing and southeast-facing) and four precipitation variables (30-minute maximum intensity, duration, total rainfall amount, and time since last event) were defined. Sediment concentrations were compared for differences between two slopes, two seed rates, and two aspect classes. Precipitation variables were analyzed to identify those that could explain significant amounts of the variability in erosion from the pipeline. The 1-time seed rate sections produced less sediment than the 3-time seed rate sections, but this was probably more a function of subsurface flow differences associated with the sections seeded with the lighter rate and the water bar construction. Precipitation intensity explained the most variability in erosion. Study sites with gentler slopes produced less sediment than the steeper sections, as expected. As vegetation became established, sediment concentrations decreased for all study sections and reached low and relatively constant levels by approximately the end of August 2009.

Natural hydrocarbon seeps harbor distinctive geological, chemical, and biological features in the marine environment. This thesis verified remote sensing signatures of seeps using in-situ observation and repeated collections of satellite imagery. Bubble streams in the Gulf of Mexico water column from four natural seep sites on the upper continental slope were imaged by a side-scan sonar, which was operated from a submarine near the seafloor, and by acoustic profilers, which were operated from surface ships. These data were correlated with sea surface slicks imaged by Synthetic Aperture Radar (SAR) on the RADARSAT satellite. Comparing non-oily bubble streams from rapidly venting mud volcanoes with oily bubble streams from shallow deposits of gas hydrate showed that they produced notably different signatures. Non-oily bubbles produced high backscatter on the side-scan sonar records, but were difficult to detect with the acoustic profilers. Oily bubbles from hydrate deposits produced acoustic shadows on the side-scan sonar records. The oily bubbles generated clear signatures extending from the seafloor to the near surface on the acoustic profile records. RADARSAT SAR images verified the presence of surface oil slicks over the hydrate deposits, but not over the mud volcanoes. This indicates that SAR imagery will not be able to capture every oil and gas seep in a region because non-oily bubble streams do not create surface oil slicks. A total of 113 natural oily seep sources were identified based on surface slicks in eleven SAR images collected over the northern continental slope. A persistence analysis verified that SAR is a dependable tool for capturing oil slicks because 93.5% of the slick sources identified in the 2001 images were corroborated with slicks in the 2002 images. The sources ranged in depth from 100 to 2000 m and 79% of the sources were in 900 meters or greater of water. Seventy-six percent of the seep sources were associated with salt less than 1500 m below the seafloor and none of the sources were located in the bottom of salt withdrawal basins. Geographical Information Systems (GIS) proved to be a useful tool in these analyses.

Background: Growth oriented entrepreneurial businesses need funding for the development of their idea, technology, product etc. However, for the businesses in the very earliest stages of development, access to funding is very limited. Growing young ventures are important job creators and positively affect growth in an economy. Bridging the gap of funding to these companies is therefore on the agenda of governments around the world.

Purpose: To describe the situation facing seed stage investing venture capitalists. I will emphasize difficulties and evaluate venture capitalists ability in addressing them. Effects of the difficulties in form of access to financing for entrepreneurs and a possible need for government intervention will be examined.

Method: Empirical information from seed stage investing venture capital organizations have been collected in the form of face-to-face interviews, email- questionnaires and a telephone interview. Organizations from Sweden, Denmark and Germany are included in the study.

Result: Several factors make seed stage investing unattractive compared to later stages. Important difficulties are higher risks, high costs for fund management, goal incongruence in the investor – venture capitalist relation and lack of bargaining power for seed venture capitalists. Environmental factorsthat have an impact on seed investing are the deal flow, the investment climate and access to soft funding. Seed stage investing is a very challenging business and the difficulties are to a large extent hard to overcome. The investors more likely have to accept them and I conclude that long term profitability of seed funds is unlikely, at least in absence of government support in form of soft funding towards the entrepreneurial businesses.

Livestock (cattle and sheep) were examined as seed disseminators for reseeding degraded Intermountain rangelands. "Hycrest" crested wheatgrass [Agropyron desertorum (Fisch. ex Link) Schult. X A. cristatum (L.) Gaert.] seed was fed to yearling Holstein steers and Suffolk ewes. Dw1g was collected from each animal type and deposited on plots of high and low densities of an annual [cheatgrass (Bromus tectorum L.)] and perennial [squirreltail (Sitanion hystrix Nutt.)] grass species. The experiment evaluated the ability of the dung to suppress the resident vegetation, and the recruitment and establishment of Hycrest seedlings emerging from the dung. Sheep dung had little suppressive effect on resident vegetation and did not provide Hycrest with a favorable microsite for germination and establishment. Cattle dung provided favorable conditions for germination of Hycrest on all plots, but seedlings were unable to compete with either high or low densities of cheatgrass. Hycrest seedlings emerging from cattle dung were more successful in establishing on squirreltail plots, and most successful in establishing on the control plots (bare ground). Cheatgrass plants located near cattle and sheep dung benefited from an input of nutrients and a gapformation (with cattle dung), which translated into greater plant height, weight, and fecundity. The squirreltail plants did not show any noticable advantages gained from adjacent dung deposition. Even though cheatgrass was suppressed by cattle dung on the surface, its roots proliferated in the soil profile immediately under the cattle dungpat to levels equal to that found in other areas within the plots.

L'objectif principal de mon travail de thèse est de comprendre les processus qui agissent sur la poussière pendant le couplage entre le milieu interstellaire galactique et le milieu intra-amas. Ce processus est d'intérêt particulier dans les phénomènes violents comme les interactions galaxie-galaxie ou le "Ram Pressure Stripping" causé par la chute d'une galaxie vers le centre de l'amas.Initialement, je me suis concentré sur le problème de la destruction de la poussière et le processus de chauffage, en re-visitant les modèles présents en littérature. J'ai particulièrement insisté sur les cas des environnements extrêmes comme le gaz chaud de type coronale (e.g., IGM, ICM, HIM) et les chocs interstellaires générés par les supernovae. Sous ces conditions les petits grains sont détruits rapidement et les gros grains sont chauffés par les collisions avec les électrons énergétiques, en rendent la distribution spectral d'énergie de la poussière très différente de ce qu'on observe dans le milieu interstellaire diffus.Pour tester nos modèles j'ai les appliqués au cas d'une galaxie en interaction, NGC 4438. Les données Herschel de cette galaxie indiquent la présence de la poussière avec une température plus élevée de ce qu'on s'attendait.Avec une analyse à plusieurs longueurs d'onde on montre que cette poussière chaude semble être dans un gaz ionisé et chaud et donc subir à la fois le chauffage collisionnel et la destruction des petits grains.De plus, je me suis focalisé sur l'énigme de longue date à propos de la différence entre les échelles de temps de destruction et formation de la poussière dans la Voie Lactée. Basées sur l'efficacité de destruction de la poussière dans les chocs interstellaires, les estimations précédentes portent à une durée de vie de la poussière plus courte que l'échelle de temps typique de sa formation dans les étoiles AGB. En utilisant un modèle de poussière récent et les dernières estimations pour l'évolution de la poussière, on a réévalué la durée de vie de la poussière dans notre Galaxie. Finalement, j'ai tourné mon attention au phénomène de "Ram Pressure Stripping''. La galaxie ESO 137-001 représente un des meilleurs cas pour étudier cet effet. Sa longue queue H2 intégrée dans une queue de gaz chaud et ionisé soulève des questions sur son possible arrachement de la galaxie ou sa formation en aval dans la queue. Basé sur des récentes simulations numériques, j'ai montré que la formation des molécules de H2 sur la surface des grains dans la queue est un scénario viable
The main goal of my PhD study is to understand the dust processing that occurs during the mixing between the galactic interstellar medium and the intracluster medium. This process is of particular interest in violent phenomena such as galaxy-galaxy interactions or the "Ram Pressure Stripping'' due to the infalling of a galaxy towards the cluster centre.Initially, I focus my attention to the problem of dust destruction and heating processes, re-visiting the available models in literature. I particularly stress on the cases of extreme environments such as a hot coronal-type gas (e.g., IGM, ICM, HIM) and supernova-generated interstellar shocks. Under these conditions small grains are destroyed on short timescales and large grains are heated by the collisions with fast electrons making the dust spectral energy distribution very different from what observed in the diffuse ISM.In order to test our models I apply them to the case of an interacting galaxy, NGC 4438. Herschel data of this galaxy indicates the presence of dust with a higher-than-expected temperature.With a multi-wavelength analysis on a pixel-by-pixel basis we show that this hot dust seems to be embedded in a hot ionised gas therefore undergoing both collisional heating and small grain destruction.Furthermore, I focus on the long-standing conundrum about the dust destruction and dust formation timescales in the Milky Way. Based on the destruction efficiency in interstellar shocks, previous estimates led to a dust lifetime shorter than the typical timescale for dust formation in AGB stars. Using a recent dust model and an updated dust processing model we re-evaluate the dust lifetime in our Galaxy. Finally, I turn my attention to the phenomenon of "Ram Pressure Stripping''. The galaxy ESO 137-001 represents one of the best cases to study this effect. Its long H2 tail embedded in a hot and ionised tail raises questions about its possible stripping from the galaxy or formation downstream in the tail. Based on recent hydrodynamical numerical simulations, I show that the formation of H2 molecules on the surface of dust grains in the tail is a viable scenario

Marine geological surveys in Asköfjärden in the southern Stockholm Archipelago hasrevealed step like features in the sediments on the Baltic sea floor. The aim of this project is toanalyse the steps and possible formation processes from the survey data. The data used aretaken from the acoustic instruments multibeam echosunder and Chirp sonar sediment profiler.The multibeam reveal the seafloor topography and can detect water column features. TheChirp sonar produce sub-bottom profiles showing the sediments down to some tens of metersunderneath the sea floor. The multibeam data show multiple crescent shaped steps as well aselliptically shaped “pockmarks”. Water column data show what could be interpreted as seepsfrom the sea floor under these features. The sub bottom profile show deformation and fluidsignatures under the steps. Gas signatures and what could be other fluids are present. Theinterpretation concludes that the formation could be from either gas or groundwater seeps. Nodefinitive conclusions can be made from the data available for the present study, andapetrophysical or geochemical study of the study area cold provide further understanding ofthe formation of the steps.

Background: The usage of AI is becoming increasingly necessary in almost every industry, including marketing and branding. AI can help managers, marketers and designers in the marketing and branding sectors to overcome realistic and practical challenges by providing data-driven results. These results could be used in making decisions. Nevertheless, implementing AI systems and the acceptance of it varies widely across different industries, with building brands is still behind.  Purpose: This research aims to develop a deeper understanding of why AI systems are not yet commonly used in the branding industry with emphasis on how it could be useful. As a result, the main opportunities and threats to the usage of AI in branding as seen by branding- and IT specialists are explored and expressed.  Method: To achieve the purpose of this study, a qualitative study was conducted. Semi-structured interviews were used as means to collect primary data and in total 15 interviews with branding and IT specialists were carried out. The data was transcribed and analyzed according to thematic analysis which emerged in four main themes.  Conclusion: The results show that AI is capable of creating brand elements, with limitations to mostly non-visual brand elements due to the lack of creativity and emotions in AI solutions. The findings indicate that the perceived possibilities of implementing AI in branding mostly are cost- and time-related since AI tends to be capable of solving tasks which are cost- and time-consuming. Furthermore, the perceived threats mainly involve i) losing a job or ii) intrude on the roles of branding professionals.

CoordenaÃÃo de AperfeiÃoamento de NÃvel Superior
A pesquisa foi conduzida em casa de vegetaÃÃo no Campus do Pici da Universidade Federal do CearÃ, no perÃodo de janeiro a marÃo de 2006, com o objetivo de estudar a resposta das culturas da mamona (Ricinus communis L.), gergelim (Sesamum indicum L.) e amendoim (Arachis hypogaea L.) a ciclos de deficiÃncia hÃdrica na fase de crescimento vegetativo. Foi avaliado o comportamento de duas cultivares de cada espÃcie, a saber: amendoim, cultivares PI 165317 (grupo âSpanishâ) e 57422 (grupo VirgÃnia); gergelim, cultivares CNPA-G3 e CNPA-G4 e mamona, cultivares Mirante e BRS 149 Nordestina. As sementes foram semeadas em tubos de PVC com 100 cm de comprimento e 15 cm de diÃmetro, em solo de textura arenosa. As cultivares foram submetidas a dois regimes hÃdricos - irrigaÃÃo diÃria e ciclos de deficiÃncia hÃdrica. Foram determinadas variÃveis relativas Ãs condiÃÃes hÃdricas da planta, trocas gasosas, crescimento da parte aÃrea e crescimento e estratificaÃÃo do sistema radicular. A colheita das plantas ocorreu aos 50, 55, 56 dias apÃs o plantio para as culturas do gergelim, amendoim e mamona, respectivamente. As variÃveis potencial hÃdrico, conteÃdo relativo de Ãgua, transpiraÃÃo foliar, fotossÃntese foliar e condutÃncia estomÃtica foram reduzidas nas trÃs culturas em resposta aos ciclos de deficiÃncia hÃdrica. A relaÃÃo entre a temperatura foliar e a ambiente aumentou em resposta ao estresse aplicado. O uso eficiente de Ãgua nÃo foi alterado nas culturas da mamona e amendoim, apresentando reduÃÃo significativa no gergelim em resposta ao dÃficit hÃdrico. A matÃria seca da parte aÃrea, das raÃzes e total, bem assim o volume radicular foram reduzidos em todas as espÃcies em resposta ao dÃficit hÃdrico. A relaÃÃo raiz/parte aÃrea aumentou em resposta ao estresse hÃdrico nas culturas do amendoim e gergelim, enquanto na mamona essa relaÃÃo permaneceu inalterada. O amendoim apresentou a menor partiÃÃo de matÃria seca para as raÃzes; o gergelim ficou numa posiÃÃo intermediÃria e a mamona destinou a maior proporÃÃo de biomassa para as raÃzes. O amendoim apresentou a maior modificaÃÃo da estratificaÃÃo do sistema radicular em resposta ao dÃficit hÃdrico, com um maior aprofundamento das raÃzes. A mamona apresentou a menor resposta e o gergelim ficou numa posiÃÃo intermediÃria. Independentemente do regime hÃdrico as trÃs culturas apresentaram maior proporÃÃo do sistema radicular nos primeiros 25 cm de solo. O nÃmero de folhas e a Ãrea foliar foram reduzidos nas trÃs espÃcies em resposta ao dÃficit hÃdrico.
A greenhouse research was carried out at the Universidade Federal do CearÃ, Campus do Pici, from January to March 2006, with the objectives of studying the response of castorbean (Ricinus communis L.), sesame (Sesamum indicum L.) and peanut (Arachis hypogaea L.) to cycles of water deficit in the early vegetative growth phase. The following cultivars for each crop were evaluated: peanut cultivars PI 165317 (group Spanish) and 57422 (group Virginia); sesame CNPA G3 and CNPA G4; and castorbean Mirante and BRS 149 Nordestina. The seeds were planted in PVC tubes 100 cm log and 10 cm wide, filled with sand soil. The cultivars received two water regime treatments: daily irrigation and cycles of water stress. Several variables were determined relative to plant water status, gas exchange, top and root growth and root system distribution in the soil profile. Plant harvest was accomplished at 50, 55 and 56 days after planting for sesame, peanut and castorbean, respectively. The variables water potential, relative water content, leaf transpiration, leaf photosynthesis and stomatal conductance were reduced in all three crops in response to water stress. The relation between leaf and ambient temperature increased in response to water stress. The water use efficiency was not affected by the stress imposed in castorbean and peanut. On the other hand, in sesame this variable decreased in response to water stress. Tops, roots and total dry matter as well as the root system volume were reduced in all species in response to water stress. Root shoot ratio increased in response to water stress for sesame and peanut, while for castorbean this relation remained unchanged. Among the crops studied, peanut plants had the smallest dry matter partition to the roots; sesame stayed in an intermediary position and castorbean partitioned the higher proportion of dry matter to roots. Peanut showed a large modification in the root system stratification in response to the water stress, with the increase of proportion of the root system in the deep soil. Castorbean showed the smaller response as far as deepening of the root system and sesame retained an intermediary position. All three crops, no matter the water regime was, had the most proportion of the root system in the first 25 cm layer of soil. The leaf number and leaf area were reduced in the three species in response to water stress.

Agribusiness leaders in emerging economies require effective business model innovation strategies to succeed in closing innovation gaps and increasing market share in the growing smallholder farmers' market. Small agribusiness seed companies in Malawi, Zambia, and Zimbabwe in southern Africa often face the challenge of closing the innovation gap in the smallholders' market, resulting in small-scale seed companies missing 90% of the smallholder farmers' seed market segment. The purpose of this multiple case study was to explore strategies that small agribusiness seed company leaders used to close innovation gaps in smallholders' markets. The conceptual framework was based on the business model innovation(BMI). Ten agribusiness seed company executives selected for their innovations in smallholder markets shared their experiences with and insights into strategies that they successfully designed and implemented in closing innovation gaps in the smallholders' market. Data were collected using semistructured interviews. The data analysis process followed De Massis and Kotlar 5-phase analysis cycle: from interview responses analysis to member checking and a review of documents on seed businesses and BMI. Three themes emerged from the data analysis: seed production model, product and market differentiation, and value chain partnerships. The implications of this study for social change are that the results could improve food and nutrition security for more than 51 million impoverished smallholder farmers throughout Sub-Saharan Africa.

Kleine, flache Gewässer gelten als sogenannte „hotspots“ der Primärproduktion und Kohlenstoffbindung. Diese Doktorarbeit zielt darauf ab, die Primärproduktion verschiedener kleiner Gewässer zu quantifizieren sowie die Mechanismen, die den Kohlenstoffkreislauf dieser Systeme beeinflussen, zu analysieren. Der Fokus liegt dabei auf dem Einfluss globaler Veränderungen, die diese Mechanismen verändern können Im ersten Abschnitt wurde die Primärproduktion (PP) in kleinen, temporären Söllen untersucht, die sehr anfällig für Störungen sind. Ich konnte zeigen, dass die PP der Sölle im Sommer außergewöhnlich hoch ist, was hauptsächlich auf eine hohe Makrophytenproduktion zurückzuführen ist Im zweiten Teil analysiere ich die Ergebnisse eines Experiments zum Einfluss erhöhter Temperaturen auf die benthische PP kleiner Gewässer im Frühjahr. Acht Mesokosmen wurden bei normalen und um 4°C erhöhten Wassertemperaturen gemäßigter Breiten betrieben. In der ersten Hälfte des Experiments konnte ich eine erhöhte benthische PP in den erwärmten Mesokosmen feststellen, die auf direkte Temperatureffekte und indirekte Auswirkungen einer höheren Nährstoffverfügbarkeit zurückzuführen war. Anfang Juni stieg jedoch der Einfluss der Makroinvertebraten auf das Periphyton in den erwärmten Mesokosmen, so dass keine Unterschiede in der PP mehr auftraten. Schließlich, untersuche ich die Resilienz eines Sees gegenüber einem plötzlichen Eintrag gelösten organischen Kohlenstoffs (DOC) aus dem terrestrischen Umland, der zu einer starken Braunfärbung des Wassers führte. Der Fokus liegt dabei auf Veränderungen der Wasserqualität und der aquatischen PP des Sees, nachdem sich die DOC-Konzentration verfünffacht hatte. Drei Jahren nach Erreichen der maximalen DOC- und Gesamt-Phosphor im See sanken diese signifikant, lagen jedoch noch immer 1,5- bzw. 2-fach oberhalb der Ausgangskonzentrationen vor dem DOC-Eintrag. Die benthische PP zeigte eine teilweise Erholung, erreichte jedoch ebenfalls nicht die Ausgangswerte.
Small, shallow freshwater ecosystems are now considered hotspots of primary production & carbon sequestration. Yet till recently they’ve been mostly neglected. This thesis aims at explaining the underlying mechanisms affecting carbon cycling in these systems, particularly focusing on how contemporary global changes alter ecological equilibria. In the first section, using a compartmental approach, I study primary production in small, temporary ponds (kettle holes) within agricultural fields that are highly susceptible to environmental & anthropogenic disturbances. I show that summertime gross primary production (GPP) in kettle holes is exceptionally high, mostly driven by a strong macrophyte production. In winter, periphyton contributes to the majority of the systems’ GPP. High summertime deposition, correlated to GPP, and low sediment mineralization rates, signified a high potential for carbon burial. In the second experiment, I test the impact of increased temperatures on periphyton production during spring. I use eight mesocosms running at normal & +4°C temperatures. Initially, I recorded elevated periphyton GPP in the warmed treatment driven by direct temperature effects & indirect effects of higher nutrient availability. By late spring, the trend is reversed due to increased grazing pressure in the warm treatment. In the third study, I investigate a lake’s resilience to a sudden brownification event: A 5-fold increase in dissolved organic carbon (DOC) concentrations. Within three years after peak brownification, the lake DOC & total phosphorous concentrations dropped significantly but seem to have plateaued at 1.5 & 2-fold their pre-brownification levels, respectively. Consequently, benthic GPP, which had collapsed due to light limitation at peak brownification, marked only a partial recovery, while phytoplankton (& whole-lake) GPP remained higher than pre-brownification levels. Phytoplankton & periphyton exhibited an inverse response to DOC & TP concentrations.

Equity crowdfunding (ECF) is the smallest of four main types of crowdfunding (CF) and has emerged as a new form of investment, where investors receive equity of a company in return for capital. Over the past years, the development of CF has given entrepreneurs the option to seek funding from a new source, instead of relying solely on venture capital (VC) and other sources of funding (Mollick, 2013). However, the implementation of regulations for ECF has not yet developed enough to make such investing equally consistent for everyone.   Equity crowdfunded ventures can potentially attract a large number of investors that can possibly create corporate governance issues between the entrepreneur and investors. Additionally, individual investors might both lack the competence or incentive to extensively research and assess a venture and make an investment. Due to the growth in ECF and the lack of knowledge of it, the purpose of this thesis was to discover the perceptions of Swedish fund managers (FMs) regarding the nature of ECF and their interest in it.   In order to fulfill the purpose of this study, previous studies were carefully examined to gain a thorough understanding of the area of study. Furthermore, the empirical findings were gathered through a course of seven semi-structured interviews of Swedish FMs.   Empirical findings suggested that ECF has remained as a means of providing only seed-stage funding for ventures and that it is a marginal phenomenon in Sweden. ECF was believed to potentially disturb the VC industry if it grew and moved to a later stage. Additionally, ECF was found to be a good option for companies that were unable to receive funding from traditional funding methods. Risks of fraud and other scandals should be prevented for ECF to maintain its popularity. The findings implied that the future of ECF remains uncertain. Based on the perceptions of Swedish FMs, ECF neither would replace nor be a threat to traditional methods.

Thesis (Ph. D. Agric. (Plant Production)) --University of Limpopo, 2019
Moringa oleifera is a multipurpose fast growing tree which is widely cultivated in tropical and subtropical regions of the world due to its numerous benefits. The benefits include medicinal use, industrial use, soil fertility, water purification, climate change mitigation as well as of nutritional value for humans and livestock. Recently, many areas globally have been rendered vulnerable to climate change as well as food insecurity. Climate change increases irregularities of rainfall and temperature patterns in semi-arid conditions. One practical way to address this challenge in the agricultural sector is to introduce more trees crop species which are found to be more tolerant than annual crops under harsh growing conditions. Moringa is one species that could be considered under variable climatic conditions for positive outcomes through climate change adaptation and mitigation as well as life sustenance against food insecurity threats. Production of moringa in South Africa is exclusively for leaf processing and consumption. To date, there is no documented information available about seed and oil yield production of moringa mainly in the Limpopo Province of South Africa. The aim of the study was to generate knowledge on moringa growth, nutritional composition, seed and oil yield production as well as its response to drought through gaseous exchange parameters, as influenced by plant density under diverse agro-ecological locations in Limpopo Province. The study was conducted in the Limpopo Province, South Africa, from November 2013 to January 2016. The study area falls within the semi-region which is characterized by low and erratic rainfall which predominately falls in summer as well as extremely low or high temperatures. A survey was conducted from November 2013 to September 2014 in five districts of the Limpopo Province. Focus group discussion, questionnaires and field observations were used for data collection. A total of 150 moringa growers formed part of the focus group and a questionnaire was administered to only thirty-one farmers, who constitute the population of farmers producing moringa within an area of 0.25 ha or more. A second study was conducted at two experimental sites in the Limpopo Province of northern part of South Africa to evaluate for the first time, the effect of plant density and cutting interval on biomass production and chemical composition of moringa grown under two diverse climatic conditions. Four different planting densities (435 000, 300 000, 200 000 and 100 000 plants/ha) were arranged in a randomized complete block design and experimental samples were replicated four times. A third study was conducted over two years to achieve additional objectives which included evaluation of gaseous exchange, biomass, seed, and oil yield. Untreated seeds of Moringa oleifera were used for establishing the trial at densities of 5 000, 2 500, 1 667 and 1 250 plants ha-1, with eight replicates. The same study was used to achieve the objective on gaseous exchange in comparison with other two naturally growing tree species of mopane (Colophospermum mopane) and marula (Sclerocarya birrea) trees growing within the moringa trial vicinity. The study was further used to evaluate the effect of planting density on biomass, grain, oil yield production and nutritional composition of Moringa oleifera trees. The last part of the study was carried out in the five districts of the Limpopo Province to determine the influence of soil physical and chemical properties on the nutritional composition of moringa leaves. The farms that were identified during the survey were also used to achieve other objectives of the study. In order to determine soil and leaf nutritional composition, soil samples were collected and analyzed for physical and chemical properties. The harvested leaves were dried at room temperature and their nutritional compositions were determined using standard methods. Findings from the studies revealed the following: The survey indicated that there are potential moringa farmers in all the districts of the province, with the intention to commercialize the tree. Majority of farmers grow moringa on 0.251.0 ha and have been producing the crop for the past 2 years. The study on planting density and cutting frequency revealed satisfactory nutritional composition in the leaves across the cutting frequencies and that, an increase in the plant density led to enhanced biomass production. The study on the monthly and seasonal gaseous exchange revealed significant differences in net photosynthetic rate, transpiration, sub-stomatal CO2 and stomatal conductance. However, planting densities of Moringa oleifera had no significant effect on all the gaseous exchange parameters measured. In a comparison of moringa with other tree species growing in the vicinity of moringa, the results differed significantly in gaseous exchange. The highest activity in photosynthetic rate (A), stomatal conductance (gs), transpiration rate (E) and sub-stomatal CO2 (Ci), as well as higher stomatal density, was found in moringa. The findings from the biomass, seed yield and oil yield study showed that the increase in measured biomass, seed and oil yield increased with increasing planting density. However, seed oil concentration was non-significant. Findings from the ecology study revealed that moringa improved soil nutritional composition; mainly in areas where the trees were more than three years old as compared to control soils where moringa had not been planted. The soil nutritional composition differed with soil textural classes with the clay soils recording higher nutrient ion values. The study revealed that moringa can be produced in many locations of the Limpopo Province without negatively affecting leaf nutritional composition. Moringa leaves contain high level of nutrients even under marginal production areas irrespective of the planting density. A population of 5000 plants ha-1 can be used for seed and oil yield production where temperatures are favourable for improved farmers’ livelihoods. The results strongly showed with no doubt, the superiority of moringa in capturing more carbon among the three species. Moringa maintained good leaf yield even under drought condition, which is an indication of its potential to act as a good sink for carbon dioxide absorption. It can, therefore, be recommended for many parts of Limpopo Province for climate change mitigation and adaptation strategies and food security. KEY CONCEPTS: agro-ecology, biomass, climate change, commercialization, drought, food security, gas exchange, leaf chemical composition, location, Moringa oleifera, oil, seed, soil textural class, survey, trees, weather, yield

The diploma thesis deals with the possibilities of using the optimization modelling software system GAMS in risk management. According to the assignment, emphasis is placed on a detailed approach to the program for those, who are interested in its use in the field of risk engineering applications. The first part of the thesis contains the knowledge to understand what the GAMS program is and what it is used for. The next part of the work provides instructions on how to download, install, activate the program and what the user interface of the program looks like. Thanks to mathematical programming, it will be explained on a project on the distribution of lung ventilators, what basic approaches may be used in risk modelling in the GAMS program on a deterministic model. The following are more complex wait-and-see models, which contains the probability parameters and here-and-now models, where we work with demand scenarios and verify whether if they meets the requirements of other scenarios or calculate costs for the highest demands. The two-stage model is also one of the here-and-now models, but it is significantly more complex in its size and range of input data, it includes additional price parameters for added or removed pieces of lung ventilators from the order.

Doutoramento em Bioquímica
Os polissacarídeos são os componentes maioritários dos grãos de café verde e torrado e da bebida de café. Os mais abundantes são as galactomananas, seguindo-se as arabinogalactanas. Durante o processo de torra, as galactomananas e arabinogalactanas sofrem modificações estruturais, as quais estão longe de estar completamente elucidadas devido à sua diversidade e à complexidade estrutural dos compostos formados. Durante o processo de torra, as galactomananas e arabinogalactanas reagem com proteínas, ácidos clorogénicos e sacarose, originando compostos castanhos de alto peso molecular contendo nitrogénio, designados de melanoidinas. As melanoidinas do café apresentam diversas atividades biológicas e efeitos benéficos para a saúde. No entanto, a sua estrutura exata e os mecanismos envolvidos na sua formação permanecem desconhecidos, bem como a relação estrutura-atividade biológica. A utilização de sistemas modelo e a análise por espectrometria de massa permitem obter uma visão global e, simultaneamente, detalhada das modificações estruturais nos polissacarídeos do café promovidas pela torra, contribuindo para a elucidação das estruturas e mecanismos de formação das melanoidinas. Com base nesta tese, oligossacarídeos estruturalmente relacionados com a cadeia principal das galactomananas, (β1→4)-Dmanotriose (Man3), e as cadeias laterais das arabinogalactanas, (α1→5)-Larabinotriose (Ara3), isoladamente ou em misturas com ácido 5-Ocafeoilquínico (5-CQA), o ácido clorogénico mais abundante nos grãos de café verde, e péptidos compostos por tirosina e leucina, usados como modelos das proteínas, foram sujeitos a tratamento térmico a seco, mimetizando o processo de torra. A oxidação induzida por radicais hidroxilo (HO•) foi também estudada, uma vez que estes radicais parecem estar envolvidos na modificação dos polissacarídeos durante a torra. A identificação das modificações estruturais induzidas por tratamento térmico e oxidativo dos compostos modelo foi feita por estratégias analíticas baseadas principalmente em espectrometria de massa, mas também em cromatografia líquida. A cromatografia de gás foi usada na análise de açúcares neutros e ligações glicosídicas. Para validar as conclusões obtidas com os compostos modelo, foram também analisadas amostras de polissacarídeos do café obtidas a partir de resíduo de café e café instantâneo. Os resultados obtidos a partir dos oligossacarídeos modelo quando submetidos a tratamento térmico (seco), assim como à oxidação induzida por HO• (em solução), indicam a ocorrência de despolimerização, o que está de acordo com estudos anteriores que reportam a despolimerização das galactomananas e arabinogalactanas do café durante a torra. Foram ainda identificados outros compostos resultantes da quebra do anel de açúcares formados durante o tratamento térmico e oxidativo da Ara3. Por outro lado, o tratamento térmico a seco dos oligossacarídeos modelo (individualmente ou quando misturados) promoveu a formação de oligossacarídeos com um maior grau de polimerização, e também polissacarídeos com novos tipos de ligações glicosídicas, evidenciando a ocorrência de polimerização através reações de transglicosilação não enzimática induzidas por tratamento térmico a seco. As reações de transglicosilação induzidas por tratamento térmico a seco podem ocorrer entre resíduos de açúcares provenientes da mesma origem, mas também de origens diferentes com formação de estruturas híbridas, contendo arabinose e manose como observado nos casos dos compostos modelo usados. Os resultados obtidos a partir de amostras do resíduo de café e de café instantâneo sugerem a presença de polissacarídeos híbridos nestas amostras de café processado, corroborando a ocorrência de transglicosilação durante o processo de torra. Além disso, o estudo de misturas contendo diferentes proporções de cada oligossacarídeo modelo, mimetizando regiões do grão de café com composição distinta em polissacarídeos, sujeitos a diferentes períodos de tratamento térmico, permitiu inferir que diferentes estruturas híbridas e não híbridas podem ser formadas a partir das arabinogalactanas e galactomananas, dependendo da sua distribuição nas paredes celulares do grão e das condições de torra. Estes resultados podem explicar a heterogeneidade de estruturas de melanoidinas formadas durante a torra do café. Os resultados obtidos a partir de misturas modelo contendo um oligossacarídeo (Ara3 ou Man3) e 5-CQA sujeitas a tratamento térmico a seco, assim como de amostras provenientes do resíduo de café, mostraram a formação de compostos híbridos compostos por moléculas de CQA ligadas covalentemente a um número variável de resíduos de açúcar. Além disso, os resultados obtidos a partir da mistura contendo Man3 e 5-CQA mostraram que o CQA atua como catalisador das reações de transglicosilação. Por outro lado, nas misturas modelo contendo um péptido, mesmo contendo também 5-CQA e sujeitas ao mesmo tratamento, observou-se uma diminuição na extensão das reações transglicosilação. Este resultado pode explicar a baixa extensão das reações de transglicosilação não enzimáticas durante a torra nas regiões do grão de café mais ricas em proteínas, apesar dos polissacarídeos serem os componentes maioritários dos grãos de café. A diminuição das reações de transglicosilação na presença de péptidos/proteínas pode dever-se ao facto de os resíduos de açúcares redutores reagirem preferencialmente com os grupos amina de péptidos/proteínas por reação de Maillard, diminuindo o número de resíduos de açúcares redutores disponíveis para as reações de transglicosilação. Além dos compostos já descritos, uma diversidade de outros compostos foram formados a partir dos sistemas modelo, nomeadamente derivados de desidratação formados durante o tratamento térmico a seco. Em conclusão, a tipificação das modificações estruturais promovidas pela torra nos polissacarídeos do café abre o caminho para a compreensão dos mecanismos de formação das melanoidinas e da relação estrutura-atividade destes compostos.
Polysaccharides are the major components of green and roasted coffee beans, and coffee brew. The most abundant ones are galactomannans, followed by arabinogalactans. During the roasting process, galactomannans and arabinogalactans undergo structural modifications that are far to be completely elucidated due to their diversity and complexity of the compounds formed. During the roasting process, galactomannans and arabinogalactans react with proteins, chlorogenic acids, and sucrose, originating high molecular weight brown compounds containing nitrogen, known as melanoidins. Several biological activities and beneficial health effects have been attributed to coffee melanoidins. However, their exact structures and the mechanisms involved in their formation remain unknown, as well as the structure-biological activity relationship. The use of model systems and mass spectrometry analysis allow to obtain an overall view and, simultaneously, detailed, of the structural modifications in coffee polysaccharides promoted by roasting, contributing to the elucidation of the structures and formation mechanisms of melanoidins. Based on this thesis, oligosaccharides structurally related to the backbone of galactomannans, (β1→4)-D-mannotriose, and the side chains of arabinogalactans, (α1→5)-Larabinotriose, alone or in mixtures with 5-O-caffeoylquinic acid, the most abundant chlorogenic acid in green coffee beans, and dipeptides composed by tyrosine and leucine, used as models of proteins, were submitted to dry thermal treatments, mimicking the coffee roasting process. The oxidation induced by hydroxyl radicals (HO•) was also studied, since these radicals seem to be involved in the modification of the polysaccharides during roasting. The identification of the structural modifications induced by thermal and oxidative treatment of the model compounds was performed mostly by mass spectrometry-based analytical strategies, but also using liquid chromatography. Gas chromatography was used in the analysis of neutral sugars and glycosidic linkages. To validate the conclusions achieved with the model compounds, coffee polysaccharide samples obtained from spent coffee grounds and instant coffee were also analysed. The results obtained from the model oligosaccharides when submitted to thermal treatment (dry) or oxidation induced by HO• (in solution) indicate the occurrence of depolymerization, which is in line with previous studies reporting the depolymerization of coffee galactomannans and arabinogalactans during roasting. Compounds resulting from sugar ring cleavage were also formed during thermal treatment and oxidative treatment of Ara3. On the other hand, the dry thermal treatment of the model oligosaccharides (alone or when mixed) promoted the formation of oligosaccharides with a higher degree of polymerization, and also polysaccharides with new type of glycosidic linkages, evidencing the occurrence of polymerization via non-enzymatic transglycosylation reactions induced by dry thermal treatment. The transglycosylation reactions induced by dry thermal treatment can occur between sugar residues from the same origin, but also of different origins, with formation of hybrid structures, containing arabinose and mannose in the case of the model compounds used. The results obtained from spent coffee grounds and instant coffee samples suggest the presence of hybrid polysaccharides in these processed coffee samples, corroborating the occurrence of transglycosylation during the roasting process. Furthermore, the study of mixtures containing different proportions of each model oligosaccharide, mimicking coffee bean regions with distinct polysaccharide composition, subjected to different periods of thermal treatment, allowed to infer that different hybrid and non-hybrid structures may be formed from arabinogalactans and galactomannans, depending on their distribution in the bean cell walls and on roasting conditions. These results may explain the heterogeneity of melanoidins structures formed during coffee roasting. The results obtained from model mixtures containing an oligosaccharide (Ara3 or Man3) and 5-CQA and subjected to dry thermal treatment, as well as samples derived from spent coffee grounds, showed the formation of hybrid compounds composed by CQA molecules covalently linked to a variable number of sugar residues. Moreover, the results obtained from the mixture containing Man3 and 5-CQA showed that CQA acts as catalyst of transglycosylation reactions. On the other hand, in the model mixtures containing a peptide, even if containing 5-CQA and subjected to the same treatment, it was observed a decrease in the extent of transglycosylation reactions. This outcome can explain the low extent of non-enzymatic transglycosylation reactions during roasting in coffee bean regions enriched in proteins, although polysaccharides are the major components of the coffee beans. The decrease of transglycosylation reactions in the presence of peptides/proteins can be related with the preferential reactivity of reducing residues with the amino groups of peptides/proteins by Maillard reaction, decreasing the number of reducing residues available to be directly involved in the transglycosylation reactions. In addition to the compounds already described, a diversity of other compounds were formed from model systems, namely dehydrated derivatives formed during dry thermal treatment. In conclusion, the identification of the structural modifications in coffee polysaccharides promoted by roasting pave the way to the understanding of the mechanisms of formation of melanoidins and structure-activity relationship of these compounds.

Understanding the formation conditions of seep carbonate is crucial to better constrain the dynamic fluid flow and chemical fluxes associate with cold seeps on the seafloor. Rare earth element (REE) in seep carbonates collected from modern cold seeps of Gulf of Mexico, Black Sea, Congo Fan, ancient seeps of Beauvoisin (Oxfordian, J3, Southeastern France) and Marmorito (Miocene, Northern Italy) were studied. Our focus has been on 5% HNO3-treated solution (authigenic carbonate minerals) of carbonates. Several crystalline forms of carbonate minerals have been selected for analysis. Total REE (ΣREE) contents in seep carbonates varies widely, from 0.068 to 43.655 ppm, but the common trend is that the ΣREE in microcrystalline phases is highest and lowest of in sparite, suggesting that the ΣREE of seep carbonates may be a function of diagenesis. The shale-normalized REE patterns of the seep carbonates show varied Ce anomalies across several seep sites and even within one site, suggesting that the formation condition of seep carbonate is variable and complex. Overall, our results show that apart from anoxic, oxic formation condition is also common at hydrocarbon seep environments.

A high-resolution seismic reflection survey was conducted during the NT07-05 cruise over the Formosa Ridge offshore southwestern Taiwan where strong and continuous bottom simulating reflections (BSR) have been observed. Previous seafloor pictures taken from a deep-towed camera indicate that there are some chemosynthetic colonies. During the NT07-05 cruise, not only large and dense chemosynthetic communities were confirmed at the plume site, ROV Hyper-Dolphin has also discovered that both deep-sea mussel Bathymodiolus platifrons, and galatheid crab Shinkaia crosnieri are vigorously populated at this site. By integrating swatch bathymetry, multichannel seismic and high-resolution seismic reflection data, we now have a better understanding on the structural characters of the cold seep site. The cold seep is situated at the summit of the Formosa Ridge southern peak. Submarine canyons that incised continental slope on both sides of the ridge are the controlling factors of the ridge formation. The sedimentary strata are generally flat lying but have been deformed by mass wasting processes. Strong BSR is observed 400 to 500 ms below the seafloor of the ridge, with many bright reflections beneath it. There is a narrow vertical blanking zone raising from BSR to the crest of the ridge. This narrow zone is interpreted to be the fluid conduit of the seep site. BSR may form a good cap to trap gas below, and this “gas reservoir” is shallower than the canyon floors on either side of the ridge. We suggest that this “ridge type” gas reservoir configuration enables the cold sea water to get into the fluid system, and forms a special kind of “hydrothermal” circulation that feeds the unusual chemosynthetic communities observed at the Formosa Ridge cold seep site.

Temporal variations in gas hydrate related geochemical signatures under different deposition conditions are the primary purposes of this study. Accreted wedge located offshore Southwestern Taiwan receives high terrigenous river materials, 100 MT/yr, at present time. It is not clear how seep environment varied during the past glacial. A 25 meters long piston core was taken offshore Southwestern Taiwan on r/v Marion DuFresne. Short piston cores and box cores were also taken on r/v OR-1. Samples were analyzed for pore water dissolved sulfide, sulfate, methane, chloride, del O18, calcium, magnesium, alkalinity, pH, and sediment AVS, pyrite, inorganic carbon, del O- 18, C13. Changes in deposition environment play a major role in the study area. Three stages of geochemical processes are identified in the 25 meters long core, interchange between reduce and oxic depositional environments, with reducing condition in the top 10 m, oxic in between 10-20 meter and reducing below the 20 meter. High concentrations of dissolved sulfide, rapid sulfate depletion, increase of methane, decrease of calcium were found in pore water in the top 10 m of sediments together with high concentrations of pyrite, relatively higher proportion of coarsegrained sediment. Concentrations of pyrite were very low in sediments between 15 to 20 meters but increased rapidly from 20 to 25 meters with a maximum concentration at 400 umol/g. Chloride concentrations also increased to a maximum concentration of 630 mM at 20 m. The rapid increase of chloride indicated gas hydrate formation at this depth. Authigenic carbonate nodules were found in sediments below 20 m. The carbonate content also increased rapidly beneath this depth. Stable isotopic carbon composition of the carbonate varied rapidly beneath 20 m with a low at -28 per mil. The existence of oxic/reducing alterations indicates that methane seep may vary in the past in the study area.

Using the NEPTUNE-Canada cable-linked ocean-floor observatory we plan continuous, real-time monitoring of the gas hydrate-associated, “Bullseye” cold vent offshore Vancouver Island. Our group inferred the presence of a massive gas hydrate deposit there, based on the significant resistivity anomaly in our controlled-source electromagnetic (CSEM) dataset, as well as anomalously heightened shear moduli, from seafloor compliance data. This interpretation was confirmed by drilling by IODP expedition 311 (site U1328), which indicated a 40 m thick gas hydrate layer near the surface. Sporadic venting and variations in blanking in yearly single-channel seismic surveys suggest the system is evolving in time. We are preparing two stationary semi-permanent imaging experiments: a CSEM and a seafloor compliance installation. These are designed not only to assess the extent of the gas hydrate deposit, but also for long-term monitoring of the gas hydrate/free gas system. The principle of the CSEM experiment is to input a particular electromagnetic signal at a transmitter (TX) dipole on the seafloor, and to record the phase and amplitude of the response at several seafloor receiver (RX) dipoles, at various TX-RX separations. The data are sensitive to the underlying resistivity, which is increased when conductive pore water is displaced by electrically-insulating gas hydrate. The experiment is controlled onshore, and can be expanded to include a downhole TX. Repeated soundings at this site, over several years, will allow measurement of minute changes in resistivity as a function of depth, and by inference, changes in gas hydrate or underlying free gas distribution. Similarly, the displacement of pore fluids by solid gas hydrate will affect elastic parameters. Thus, seafloor compliance data, the transfer function between pressure and seafloor displacement time series, most sensitive to shear modulus as a function of depth, will be gathered continuously to monitor the evolution of the gas hydrate distribution.

碩士
國立中興大學
化學工程學系所
104
Bitter melon seed oil (BMSO) is rich in α-eleostearic acid (α-ESA) that is known for suppressing both obesity and tumor growth. However, this fatty acid is relatively unstable and easily oxidized. The process of particles from gas-saturated solution (PGSS) was often employed in oil encapsulation. This research therefore employed PGSS for the encapsulation of BMSO to improve the stability of the target fatty acid. Supercritical carbon dioxide extraction was used to acquire BMSO under a pressure of 330 bar, a temperature of 40 oC and a solvent-to-solid ratio of 100. The process yielded 647 mg of α-ESA per gram of BMSO. PGSS process using polyethylene glycol (PEG 8000) as a carrier was then used to encapsulate BMSO to create a micro-level powder. In the PGSS pre-test, pressure, temperature and PEG / BMSO ratio in the feed were used as the variables to investigate how they affected total yield (TY) of the encapsulated material, α-ESA concentration (Cen-ESA), encapsulation efficiency (EE) and α-ESA recovery (R). Results of the pre-test showed that the temperature change does not significantly affect the dependent variables investigated. A 2-factor and 3-level design was employed with pressures at 130, 145, and 160 bar and PEG / BGSO feed ratio at 1, 1.5, and 2. Experimental results were then subject to response surface methodology (RSM) to investigate how these 2 factors affected TY, Cen-ESA, EE and R. Results of the RSM test showed that TY was positively correlated with pressure, while Cen-ESA, EE and R were affected by both pressure and feed ratio. When pressure was set to 160 bar and feed ratio set to 1.5, the result was: Cen-ESA = 322.1 mg/g, EE = 65.3%, and R = 44.2%. RSM results predicted an optimal condition of a pressure of 159 bar and feed ratio of 1.65 to obtain TY = 34.8%, Cen-ESA = 317.6 mg/g, EE = 64.8%, and R = 44.8%. Actual experiment under these conditions gave similar results with TY = 35.2%、 Cen-ESA = 317.9 mg/g、 EE = 65.1%、R = 45.2%. Products were then exposed to room temperature for 25 days. α-ESA concentration for the encapsulated material was higher than that of un-encapsulated extract, demonstrating that the PGSS encapsulation of BMSO did indeed help delay the oxidation of α-ESA.

博士
臺灣大學
地質科學研究所
98
This study has successfully set up Taiwan’s first gas hydrate synthesizing apparatus which has the capability for recording experimental temperature and pressure. A large (at least 100 grams) methane-saturated (more than 99%) solid hydrate sample can be produced by simply introducing highly pressurized methane gas into the reactor that contains an ice-seed sample (Otherwise called an Ice Seed Method experiment). The appearance and texture of manufactured hydrates remain the same as those of the original ice-seed samples. Also, by this system, we can prepare a variety of samples mixed with different sediments for meeting the needs of follow-up studies. The process of the “Ice Seed Method” can be divided into two main stages, "Pressurization" and "Heating". Firstly, we investigated the influence of different experimental parameters (Initial temperature, pressure, and fabric of ice-seed sample, etc.) on ice-to-hydrate converting rates and total hydrate yields during the pressurization stage. This study has shown for the first time that before the second heating stage, a certain amount of gas hydrate (For example, 12% of ice can be converted to hydrate within 47 min from an ice-seed sample with a porosity of 66%) can be produced after introducing highly pressurized methane gas into the reactor while the texture of sample remains constant. We found that the amount of methane hydrates produced is inversely proportional to the initial temperature; the lower the temperature, the larger the amount of formed hydrate. The converting rates can be even faster in experiments with a slow pressurization procedure or samples mixed with sediments. A 25% conversion can be achieved in a slowly pressurized run within 1042 min. We also found that if there are more hydrates formed during the pressurization stage, the cost of energy and time can be cut down dramatically during the succeeding heating stage for the purpose of making a completely saturated methane hydrate sample. By analyzing experimental data along with some SEM work, this study proposed a simple schematic model to reasonably explain some unique characteristics of the “Ice Seed Method”, such as why hydrate samples can be manufactured with different degrees of cementation, or why the appearance and texture of samples can be maintained after the heating stage. By adjusting some experimental parameters properly, hydrate samples with different features can be manufactured by the guideline obtained from this study. Although there were some previous researches concentrated on how to promote or retard the formation of gas hydrates in a liquid system by adding different additives, no report about how to improve the conversion efficiency of the “Ice Seed Method” can be found. This study found out that the total amount of methane or carbon dioxide hydrates formed during the “Pressurization” stage can substantially increase as some alcohol vapor (methanol, ethanol and 1-propanol) is added into the system. The one that has the best promoting effect is ethanol while the initial system temperature is set at 270.2K. Nearly 91% of ice seed can be converted into methane hydrates during pressurization stage. The discovery may have considerable practical value for the transportation and storage of natural gas. The preliminary hypothesis for this promoting effect is that the presence of these trace gaseous alcohol is able to slow down the formation rate of hydrates and prevent the generation of impervious hydrate film covering the ice core in the early stage. Instead, the formed hydrates are permeable because of a different texture so the inner ice can keep converting into hydrates by continuously interacting with methane molecules. Maybe the catalytic efficiency has a relationship with the alcohol vapor pressure which changes with the temperature. According to our experimental data, the best catalytic efficiency for each kind of alcohol may be achieved at different temperatures when the vapor pressures are all around 10mmHg.

碩士
國立中興大學
化學工程學系所
103
In this study the method of supercritical particles from gas-saturated solution (PGSS) has been used for producing the micro-particles of bitter gourd seed oil (BGSO) coated by sucrose stearate (SS). During supercritical PGSS co-precipitation preliminary experiment, total yield, drug content of the coating have been investigated by changing the pressure, temperature, and feed ratio of BGSO and SS. And then the response surface methodology (RSM) experimental design based on the two variables of pressure (120 bar to 160 bar) and the feed ratio (0.5 to 1.5) of BGSO and SS has been implemented to investigate the impacts of the two variables on total yield, drug content, and α-eleostearic acid (α-ESA) recovery rate of the coating. The experimental results indicate the correlation of opposite trend between the total yield and drug content of the coating. The three responses predicted by RSM with optimal conditions of pressure at 120 bar, feed ratio at 1.5 are the total yield of coating at 45.96%, the drug content at 25.76%, and α-ESA recovery rate at 29.82%, all of which are similar to the experimental values. It has been revealed by the induction that the drug content of the coating has been significantly affected by the feed ratio. As for the stability test, keeping the PGSS coating in room temperature for 30 days can slow down the decline of α-ESA concentration. The bitter gourd seed oil coated by sucrose stearate produced by supercritical PGSS can indeed slow down the degradation of α-ESA, which can serve as a protection. Keywords: particles from gas-saturated solution, bitten melon, α-eleostearic acid, sucrose stearate, encapsulation

碩士
國立臺北藝術大學
傳統藝術研究所
95
This paper is based on the related studies of Nankuan percussion music found in Taiwan today. First, what we call Nankuan opera is directly related to the operas that are sang by Chiuan Chiang dialogue. Mainly, it includes Li-yuan, Marionette, Puppet and Gaojia Opera in Chiuan Chiang, and Chi-zi (Seven Children Opera) and Kaoka operas in Taiwan. This thesis primarily analyzes Li-yuan opera. First, the thesis starts with briefly discussion of Chjui-to, lyrics(lines), movements and distinct use of percussion music in Li-yuan Opera. Second, I will distinguish and compare the different tone qualities of percussion in Li-yuan and other popular traditional Chinese operas. Comparatively, the thesis will take Gao Wen Ju as a model to analyze how it is produced in Chi-zi Opera, Li-yuan opera and Kaoka opera by different percussion instruments. The relationship between Li-yuan and other Nankuan operas in percussion music is that they are both moderately connected to Chiuan Chiang. Toward the end of Ching dynasty, Li-yuan was further to absorb Peking Opera’s percussion music and blended it into its opera created what we call North percussion music today. Due to North percussion music’s popularity in Li-yuan opera, it will be discussed in this thesis. Furthermore, in order to illustrate the different tone qualities of percussion instruments in traditional Chinese operas, North and BaiGuan percussion music will also be demonstrated here. The main emphasis of this part will be on their physical characteristics, using spectra and figures to display how they would be sounded and constructed, as it will be consequently compared with Li-yuan percussion music.

This research explores a disability community’s success in drawing public attention to an unlawful development of policy, that community’s efforts in resistance, and the experiences of those individuals in relation to subsequent neoliberal silencing. Specifically, this study examines the experiences of people on disability assistance in British Columbia who successfully appealed the Ministry’s unjust denial of the Community Volunteer Supplement (CVS) and documents participants’ reactions to the government’s later repeal of the CVS program. Five individuals were interviewed about their experiences in resisting the Ministry of Social Development and Social Innovation’s practice to wait list CVS applicants, a benefit they were legislatively entitled to receive. Of the participants interviewed, three identified as women and two identified as men. Utilizing a post-structural feminist theory, influenced by critical disability theory and Foucault, a key finding of this research is that participants’ experiences with the CVS is connected to their experiences of poverty, resistance, and community.
Graduate
2017-08-01
0630
0452
0617
cwitkowskyj@gmail.com

碩士
國立屏東科技大學
水產養殖系
92
Abstracts The major dilemma of Taiwan fish seed industry is that the market is limited in sale. Besides, Taiwan has to compete with other Southeastern Asian countries especially after entering the WTO (World Trade Organization). So the breeders should endure more competitive pressure from the same industry production worldwide. To assess the possibility of establishing the fish seed area in Hong-mao-gan (Kaohsiung city) and Jia-dong (Pingtung county), this study employed the SWOT analysis to take a thorough interviewing those breeders in these two study area and then evaluated the international competitive strategy of fish seed industry in Taiwan. The results showed the Taiwan’s fish seed industry is full of competitiveness, and should, make efforts (1) to develop superior technique of transporting live fish to farther area; (2) to carry out the certificate system of fish seed to assure the quality; (3) to establish fish genetic resources bank and introduce or develop new species; (4) to pursue organization cooperation and unify the market expand and sale. With these efforts, one can make sure to establish the superior native fish seed and further to increase the Taiwan fish seed industry’s competitive ability and new technique development.

Salinity continues to be one of the world’s most serious environmental problems in agriculture. The increasing world population and urbanization are forcing farmers to utilize marginal lands as well as poor quality water. One of the strategies in dealing with salinity is growing salt tolerant plants and there has been increased need to understand the effects of salinity on crops. Owing to its high nutritive value and wide adaptability to diverse environments, amaranth is considered a promising crop for marginal lands and semiarid regions. The objective of the study was to investigate the response of amaranth to salinity stress and evaluate stress amelioration by calcium and seed priming. Salinity tolerance during germination and early seedling growth was examined for six genotypes of amaranth (Amaranthus species) at different salt concentrations ranging from 0 to 200 mM NaCl or Na2SO4. Enhancement of germination was observed at 25 mM, while increasing salt concentrations reduced the germination percentage as well as germination rate. A.tricolor and Accession ’83 were able to germinate in 200 mM NaCl while there was no germination at 200 mM Na2SO4 in all the genotypes. Overall, Accession ’83 was the most resistant and A. hybridus the most sensitive genotype, particularly at high salt concentrations. Inhibition of germination was greater in Na2SO4 than in NaCl salinity treatments. Amaranth was more salt tolerant at germination than at seedling growth. Seedling emergence, survival and growth were reduced by salinity and at much lower concentrations than at seed germination. Differences in salt tolerance were noted among the genotypes. Salinity stress was initiated at different growth stages (cotyledon stage, 2-leaf stage and 4-leaf stage) in order to determine whether tolerance of amaranth differs with the stage of development. The treatment either continued until termination of the experiment or for 14 days at each stage. Amaranth plants were less sensitive to salinity when the stress was initiated at the 4-leaf stage. Lower salt concentrations had less detrimental effects than higher concentrations when applied at the cotyledon stage. Application of low salt concentration at cotyledon stage for 14 days did not have any effect on plant growth. The results indicate that it is feasible to use saline water for growing amaranth with minimum yield losses if salt concentration, duration of exposure and time of salinization are carefully managed. Differences in salinity tolerance among amaranth genotypes were analyzed in terms of plant survival, growth, gas exchange, water use and leaf anatomical changes. A. hypochondriacus and A. cruentus showed greater tolerance to salinity since they survived in 200 mM NaCl treatment and the reduction in growth at 50 and 100 mM was lower than that of A. tricolor and Accession ’83. A. hypochondriacus and A. cruentus were more efficient water users and partitioned photosynthates towards shoot growth as opposed to the other two genotypes. Photosynthetic rate, stomatal conductance, stomatal density and apertures were reduced by salinity but were higher in A. tricolor than in A. cruentus. Salinity resulted in A. cruentus developing thicker leaves compared to A. tricolor. Productivity on saline soils can be increased by growing genotypes more tolerant to salinity. The interactive effect of salinity and water stress on amaranth plant growth was evaluated. It was found that the reduction in shoot growth was greater in plants submitted to water stress than in those submitted to salt or salt + water stress. Water use efficiency was increased while leaf water and osmotic potentials were reduced by the salinity stress treatments. In drying soil plants previously salinized had a greater degree of osmotic adjustment, so that plants were able to continue growth for a longer period compared to water stressed plants. The effect of calcium in ameliorating salt stress was investigated. Supplementary calcium, either as CaSO4 or CaCl2 ameliorated the negative effects of salinity on growth, gas exchange, membrane permeability and mineral uptake. In a separate experiment it was shown that it is feasible to mitigate the adverse effects of salinity on amaranth seed germination, seedling survival and growth by seed priming and that the positive effect of priming persisted to vegetative growth stage. Priming with CaSO4 + NaCl showed a greater positive response than priming with the individual salts.
Thesis (PhD (Plant Production andSoil Science))--University of Pretoria, 2007.
Plant Production and Soil Science
unrestricted

Seed addition experiment was conducted on the moisture gradient with aim to demonstrate that many species not accounted by current measures of species pools in a site should be included because they are in fact able to establish successfully if biotic filter is removed. Transplant experiment was established to compare the sensitivity of seedling recruitment and survival of transplants in the field. Recruitment of seedlings in field was observed and compared with germination of seeds under different chilling treatments in laboratory.

A study was conducted to determine what impact high white-tailed deer (Odocoileus virginianus) densities were having on the native grasslands of a tallgrass: aspen forest tract embedded within an agro-urban setting. Due to excessive spring moisture, row-crops were unavailable the first year. Using microhistological fecal analysis to determine dietary composition, deer were assessed to be placing the site’s favoured native plant species at risk of extirpation. Measuring woody stem abundance and height along and near the prairie: forest ecotone, deer were found to restructure woody growth but not directly influence encroachment rates. Indirectly, however, deer facilitated forest encroachment and prairie degradation through seed dispersal, nitrogen deposition, gap-dynamics, and trampling. Comparing dietary composition to nutritional data, deer grazed to maximize fitness, selecting foods high in IVDMD, minimizing energy expenditure, and optimizing CP. High crop CP was offset by intensively grazing particular native plants. ADF was an effective nutritional marker, not AIA.