Análise da influência do efeito esteira de aerogeradores no microclima na superfície do solo: o caso do parque eólico piloto de Macau/RN

This study aimed to evaluate the microclimate changes surrounding the wind farm Macau Pilot / RN, present in the municipality of the same name. To achieve this goal made use of remote sensing techniques using Landsat - 5 TM and 7 ETM +, from which made it possible evaluation of temperature changes on the surface, this around the park in periods prior to its implementation, to the today. For evaluation of the temperature data that has been generated by applying a template was performed its correlation with field data collection and evaluated the degree of correlation, in order to confirm the validity of the data acquired by satellite. Also held was a characterization of the climate of the region based on the data of this climatological station in Macau. Once collected this data made possible the evaluation of climate change policy in the study region. After validation of the temperature models, an analysis of the generated temperature histograms was performed visually could not identify any significant change. However when analyzing the temperature data at a higher level of detail, a data pattern of behavior was detected for both periods evaluated, yet could not see a distinction between the periods of pre-operation of the park, and post-operation . From this result was levantas hypotheses to explain the behavior of the data, the first of which is the presence of moisture in the soil, and the second to the soil composition. In order to validate the hypotheses were applied PDI techniques, involving a combination of different RGB bands of Landsat 5 and the implementation of Reason bands procedure that might show the elements present on the soil surface.

Oceanographic investiations from the Sea of Ochotsk

The Sea of Okhotsk is a marginal sea of the Pacific Ocean, which is characterized by strong variations in the productivity and sediment supply due to sea ice transport and river input. Furthermore the variations in the hydrological cycle determine the formation of the SOIW (Sea of Okhotsk Intermediate Water) which plays an important role in the ventilation processes in the intermediate water of the N-Pacific. Isotope data measured on planktonic and benthic foraminifera, sedimentological and geochemical studies of sediment cores and surface samples from the Sea of Okhotsk are used to reconstruct the paleoceanography during the past 350.000 years. The dating and correlation of the sediments are based on oxygen isotope stratigraphy, absolute ages, magnetic susceptibility as well as a detailled tephrachronology of the entire basin. The sedimentation rates are characterized by temporal and spatial variations. The maximum sedimentation rate takes place at the continental slope off Sakhalin due to the input of the Amur River, the sea ice drift and the high productivity. The sedimentation rate in the eastern part of the Sea of Okhotsk is generelly high because of the influence of the nutrient-rich Kamchatka Current. In the central and northern parts of the Sea of Okhotsk, areas with low productivity and reduced terrestrial supply, the sedimentation rate is the lowest. The analyses of the surface sediment samples make it possible to characterize the (sub)- recent sediment supply and transportation processes. The bulk sediment measurements, isotope data and the accumulation rate of ice-rafted debris (IRD) show a dominant sea ice cover and a region with a high productivity as well as a high Amur River input in the western part of the sea. The eastern part of the Sea of Okhotsk, however, is marked by the predominance of warm and nutrient-rich water masses coming from the Kamchatka Current which restricts the sea ice cover. This is reflected in low content of ice-rafted debris and high productivity proxies as well as in isotope data. The deposits of the Sea of Okhotsk are characterized by terrestrial, biogenic and volcanogenic sediment input which varies temporally and spatially. Here, the sedimentation pattern is dominated by the terrestrial input. Bulk sediment measurements and sample analyses of the > 63 micron particle input make it possible to distinguish glacial and interglacial fluctuations. The sedimentation processes during glacial times are determined by a high content of ice-rafted debris, whereas the primary production is higher during interglacial periods. During the last glacial/interglacial cycle the IRD-distribution pattern indicates a strong sea ice transport in the western part and in large areas of the open sea in the eastern part of the Sea of Okhotsk with a relatively constant ice-drift system. The IRD flux in sediments of the oxygen isotope Stage 6 reflects a new sedimentation pattern in the eastern part of the sea. This high IRD accumulation rate indicates ice advances beyond the shelf margin and an iceberg transport from NE-E direction into the Sea of Okhotsk. The several large, brief, negative anomalies in d13C values of Neogloboquadrina pachyderma (s) show releases of methane from basin sediments which correspond to periods of relative sea level falls. The high sedimentation rates on the Sakhalin slope allow insights into the climatic history in Holocene and indicate shorter-scale variations oscillation in Stage 3, which correlate with the global climatic changes. These variations are described as Dansgaard-Oeschger cycles in Greenland ice cores and as Heinrich-Events in several marine sediment cores from the N-Atlantic.

(Table 1) Age determination on monospecies planktonic foraminifera of sediment core AN25-934

Reconstruction of regional climate and the Okhotsk Sea (OS) environment for the Last Glacial Maximum (LGM), deglaciation and Holocene were performed on the basis of high-resolution records of ice rafted debris (IRD), CaCO3, opal, total organic carbon (TOC), biogenic Ba (Ba_bio) and redox sensitive element (Mn, Mo) content, and diatom and pollen results of four cores that form a north-southern transect. Age models of the studied cores were earlier established by AMS 14C data, oxygen - isotope chronostratigraphy and tephrochronology. According to received results, since 25 ka the regional climate and OS environmental conditions have changed synchronously with LGM condition, cold Heinrich event 1, Bølling -Allerød (BA) warming, Younger Dryas (YD) cooling and Pre-Boreal (PB) warming recorded in the Greenland ice core, North Atlantic sediment, and China cave stalagmites. Calculation of IRD MAR in sediment of north-south transect cores indicate an increase of sea ice formation several times in the glacial OS as compared to the Late Holocene. Accompanying ice formation, increased brine rejection and the larger potential density of surface water at the north shelf due to a drop of glacial East Asia summer monsoon precipitation and Amur River run off, led to strong enhancement of the role of the OS in glacial North Pacific Intermediate Water (NPIW) formation. The remarkable increase in OS productivity during BA and PB warming was probably related with significant reorganisation of the North Pacific deep water ventilation and nutrient input into the NPIW and OS Intermediate Water (OSIW). Seven Holocene OS millennial cold events based on the elevated values of the detrended IRD stack record over the IRD broad trend in the sediments of the studied cores have occurred synchronously with cold events recorded in the North Atlantic, Greenland ice cores and China cave stalagmites after 9 ka. Diatom production in the OS were mostly controlled by sea ice cover changes and surface water stratification induced by sea-ice melting; therefore significant opal accumulation in sediments of this basin begin from 4-6 ka ago simultaneously with a remarkable decrease of sea ice cover.

Design rationnel de nanothermomètres programmables à base d’ADN

Développer de nouveaux nanomatériaux, interrupteurs et machines nanométriques sensibles à de petites variations de température spécifiques devrait être de grande utilité pour une multitude de domaines œuvrant dans la nanotechnologie. De plus, l’objectif est de convaincre le lecteur que les nanotechnologies à base d’ADN offrent d’énormes possibilités pour la surveillance de température en temps réel à l’échelle nanométrique. Dans la section Résultats, nous exploitons les propriétés de l’ADN pour créer des thermomètres versatiles, robustes et faciles à employer. En utilisant une série de nouvelles stratégies inspirées par la nature, nous sommes en mesure de créer des nanothermomètres d’ADN capables de mesurer des températures de 25 à 95°C avec une précision de <0.1°C. En créant de nouveaux complexes d’ADN multimériques, nous arrivons à développer des thermomètres ultrasensibles pouvant augmenter leur fluorescence 20 fois sur un intervalle de 7°C. En combinant plusieurs brins d’ADN avec des plages dynamiques différentes, nous pouvons former des thermomètres montrant une transition de phase linéaire sur 50°C. Finalement, la vitesse de réponse et la précision des thermomètres développés et leur réversibilité sont illustrées à l’aide d’une expérience de surveillance de température à l’intérieur d’un unique puits d’un appareil de qPCR. En conclusion, les applications potentielles de tels nanothermomètres en biologie synthétique, imagerie thermique cellulaire, nanomachines d’ADN et livraison contrôlée seront considérées.

Design rationnel de nanothermomètres programmables à base d’ADN

Développer de nouveaux nanomatériaux, interrupteurs et machines nanométriques sensibles à de petites variations de température spécifiques devrait être de grande utilité pour une multitude de domaines œuvrant dans la nanotechnologie. De plus, l’objectif est de convaincre le lecteur que les nanotechnologies à base d’ADN offrent d’énormes possibilités pour la surveillance de température en temps réel à l’échelle nanométrique. Dans la section Résultats, nous exploitons les propriétés de l’ADN pour créer des thermomètres versatiles, robustes et faciles à employer. En utilisant une série de nouvelles stratégies inspirées par la nature, nous sommes en mesure de créer des nanothermomètres d’ADN capables de mesurer des températures de 25 à 95°C avec une précision de <0.1°C. En créant de nouveaux complexes d’ADN multimériques, nous arrivons à développer des thermomètres ultrasensibles pouvant augmenter leur fluorescence 20 fois sur un intervalle de 7°C. En combinant plusieurs brins d’ADN avec des plages dynamiques différentes, nous pouvons former des thermomètres montrant une transition de phase linéaire sur 50°C. Finalement, la vitesse de réponse et la précision des thermomètres développés et leur réversibilité sont illustrées à l’aide d’une expérience de surveillance de température à l’intérieur d’un unique puits d’un appareil de qPCR. En conclusion, les applications potentielles de tels nanothermomètres en biologie synthétique, imagerie thermique cellulaire, nanomachines d’ADN et livraison contrôlée seront considérées.

Accumulation rates of plant-wax-derived long-chain C25 to C35 odd-numbered n-alkanes and d13C values of the n-C31 alkane of ODP Hole 175-1077B

The dominant forcing factors for past large-scale changes in vegetation are widely debated. Changes in the distribution of C4 plants-adapted to warm, dry conditions and low atmospheric CO2 concentrations (Collatz et al., 1998, doi:10.1007/s004420050468) -have been attributed to marked changes in environmental conditions, but the relative impacts of changes in aridity, temperature (Pagani et al., 1999, doi:10.1126/science.285.5429.876; Huang et al., 2001, doi:10.1126/science.1060143) and CO2 concentration (Cerling et al., 1993, doi:10.1038/361344a0; Kuypers et al., 1999, doi:10.1038/20659) are not well understood. Here, we present a record of African C4 plant abundance between 1.2 and 0.45 million years ago, derived from compound-specific carbon isotope analyses of wind-transported terrigenous plant waxes. We find that large-scale changes in African vegetation are linked closely to sea surface temperatures in the tropical Atlantic Ocean. We conclude that, in the mid-Pleistocene, changes in atmospheric moisture content - driven by tropical sea surface temperature changes and the strength of the African monsoon - controlled aridity on the African continent, and hence large-scale vegetation changes.

Alkenone unsaturation index and alkenones in ODP Hole 161-977A

A number of essential elements closely related to each other are involved in the Earth's climatic system. The temporal and spatial distribution of insolation determines wind patterns and the ocean's thermohaline pump. In turn, these last two are directly linked to the extension and retreat of marine and continental ice and to the chemistry of the atmosphere and the ocean. The variability of these elements may trigger, amplify, sustain or globalize rapid climatic changes. Paleoclimatic oscillations have been identified in this thesis by using fossil organic compounds synthesized by marine and terrestrial flora. High sedimentation rate deposits at the Barents and the Iberian peninsula continental margins were chosen in order to estimate the climatic changes on centennial time resolution. At the Barents margin, the sediment recovered was up to 15,000 years old (unit ''a'', from latin ''annos'') (M23258; west of the Bjørnøya island). At the Iberian margin, the sediment cores studied covered a wide range of time spans: up to 115,000 a (MD99-2343; north of the Minorca island), up to 250,000 a (ODP-977A; Alboran basin) and up to 420,000 a (MD01-2442, MD01-2443, MD01-2444, MD01-2445; close to the Tagus abyssal plain). At the northern site, inputs containing marine, continental and ancient reworked organic matter provided a detailed reconstruction of climate history at the time of the final retreat of the Barents ice sheet. At the western Barents continental slope, warm climatic conditions were observed during the early Holocene (~from 8,650 a to 5,240 a ago); in contrast, an apparent long-term cooling trend occurred in the late Holocene (~from 5,240 a to 760 a ago), in consistence with other paleoarchives from northern and southern European latitudes. The Iberian margin sites, which were never covered with large ice sheets, preserved exceptionally complete sequences of rapid events during ice ages hitherto not studied in such great detail: during the last glacial (~from 70,900 a to 11,800 a ago), the second glacial (~from 189,300 a to 127,500 a ago), the third ice age (~from 278,600 a to 244,800 a ago) and the fourth (~from 376,300 a to 337,500 a ago). In this thesis, crucial research questions were brought up concerning the severity of different glacial periods, the intensity and rates of the recorded oscillations and the long distance connections related to rapid climate change. The data obtained provide a sound basis to further research on the mechanisms involved in this rapid climate variability. An essential point of the research was the evidence that, over the past 420,000 a, at the whole Iberian margin, warm and stable long periods similar to the Holocene always ended abruptly in few centuries after a gradual deterioration of climate conditions. The detailed estimate of past climate variability provides clues to the natural end of the present warm period. Returning to an ice age in European lands would be exacerbated by a number of factors: a lack of differential solar heating between northern and southern north Atlantic latitudes, enhanced evaporation at low latitudes, and an increase in snowfall or iceberg discharges at northern regions. It must be emphasized that all climatic oscillations observed in this thesis were caused by forces of nature, i.e. the last two centuries were not taken into consideration.

Sea surface temperatures, alkenones and sedimentation rate from ODP Hole 161-977A

A continuous high-resolution Western Mediterranean sea surface temperature (SST) alkenone record spanning the past 250,000 years shows that abrupt changes were more common at warming than at cooling. During marine isotope stage (MIS) 6, SST oscillated following a stadial-interstadial pattern but at lower intensities and rates of change than in the Dansgaard/Oeschger events of MIS 3. Some of the most prominent events occurred over MISs 5 and 7, after prolonged warm periods of high stability. Climate during the whole period was predominantly maintained in interglacial-interstadial conditions, whereas the duration of stadials was much shorter.

Age model and chemistry of sediment core STK7 from Steisslinger See

Stable isotope records for carbon and oxygen in bulk carbonates, carbon in bulk organic matter, and for total and chromium-reducible sulfur in a lacustrine sediment core from Lake Steisslingen (Southwest Germany) show several distinct and abrupt shifts during the last 15,000 years. Variations in the isotopic composition of authigenic carbonates indicate two major phases in the lake history. In the pre-Holocene, the hydrological budget of the lake was apparently stable. Variations of delta18O values of authigenic carbonates were, therefore, dominantly controlled by temperature changes. A decrease in the delta18Ocarb values of about 2 per mil at the Allerød/Younger Dryas transition is interpreted as a drop in mean annual air temperatures of approximately 5°C. An abrupt temperature increase of a similar magnitude is inferred at the Younger Dryas/Preboreal boundary. Throughout most of the Holocene, the isotopic composition of authigenic carbonates was influenced by marked changes in the hydrological budget of the lake. A major positive excursion in the delta13Ccarb and delta18Ocarb values at the beginning of the Atlantic and a smaller one in the Preboreal were related to evaporation effects, which indicate that dry climatic conditions must have prevailed at that time. A simultaneous increase in delta13C values of bulk organic matter at the beginning of the Atlantic suggests a high level of productivity in the lake. As a consequence, aqueous sulfate became limited as indicated by variations in the delta34S values of total and chromium-reducible sedimentary sulfur. Therefore, we conclude that the beginning of the Atlantic was characterized not only by dry but also by warm climatic conditions, which triggered a higher productivity in the lake. In the Subatlantic sediments, large variations in carbon, oxygen, and sulfur isotope ratios were observed as a result of human activities, causing considerable perturbations in the biogeochemical element cycling of Lake Steisslingen. Results obtained by the study of the continuous 15 ka record of Lake Steisslingen document clearly that isotopic proxy data from lacustrine sediments can provide useful information on environmental and climatic changes of local, regional, and in the case of the Younger Dryas event, of even hemispherical significance.

Late Holocene diatom abundaces in sediment core HC-11

The study of diatoms in core HC11 collected from the southwestern part of Chukchi Sea, allowed to distinguish 3 diatoms ecological zones, reflecting paleoenvironmental changes during the last 2300 years. The sediment age was based on the sedimentation rates, determined by 210Pb and radiocarbon dating of mollusk shells. The environmental changes of Chukchi Sea revealed by examination of diatoms correlates with global climate changes - the warming of the early and middle Subatlantic and cooling of the late Subatlantic (Little Ice Age). Warming early and middle Subatlantic in the Chukchi Sea was probably stronger than the warming of the late 20th century and was not accompanied by significant changes in sea level.

Climate Change or Urbanization? Impacts on a Traditional Coffee Production System in East Africa over the Last 80 Years

Global environmental changes (GEC) such as climate change (CC) and climate variability have serious impacts in the tropics, particularly in Africa. These are compounded by changes in land use/land cover, which in turn are driven mainly by economic and population growth, and urbanization. These factors create a feedback loop, which affects ecosystems and particularly ecosystem services, for example plant-insect interactions, and by consequence agricultural productivity. We studied effects of GEC at a local level, using a traditional coffee production area in greater Nairobi, Kenya. We chose coffee, the most valuable agricultural commodity worldwide, as it generates income for 100 million people, mainly in the developing world. Using the coffee berry borer, the most serious biotic threat to global coffee production, we show how environmental changes and different production systems (shaded and sun-grown coffee) can affect the crop. We combined detailed entomological assessments with historic climate records (from 1929-2011), and spatial and demographic data, to assess GEC's impact on coffee at a local scale. Additionally, we tested the utility of an adaptation strategy that is simple and easy to implement. Our results show that while interactions between CC and migration/urbanization, with its resultant landscape modifications, create a feedback loop whereby agroecosystems such as coffee are adversely affected, bio-diverse shaded coffee proved far more resilient and productive than coffee grown in monoculture, and was significantly less harmed by its insect pest. Thus, a relatively simple strategy such as shading coffee can tremendously improve resilience of agro-ecosystems, providing small-scale farmers in Africa with an easily implemented tool to safeguard their livelihoods in a changing climate.

Amidos crioulos: caracterização fundamental e influência de biopolímeros nas propriedades funcionais do amido

O trabalho apresentado nesta tese focou-se no estudo do amido, nomeadamente na avaliação das características físico-químicas, morfológicas, térmicas e reológicas do amido de seis variedades de milho crioulo, preservadas no estado de Santa Catarina (Brasil), com o intuito de contribuir para a valorização e preservação de variedades locais que são cultivadas em sistemas de produção orgânica, também conhecidas como variedades crioulas. Estas sementes são importantes quer para a preservação da biodiversidade quer para os pequenos produtores que as conservam e as produzem fazendo uso de uma agricultura sustentável e independente comercialmente. Para além da caracterização dos amidos crioulos foram também analisadas as alterações que ocorrem nos processos de gelatinização e retrogradação do amido quando realizados na presença de outros biopolímeros, nomeadamente a quitosana e galactomananas. No Capítulo I é apresentada uma breve revisão do conhecimento científico sobre o amido e sobre a quitosana e galactomananas, os outros biopolímeros utilizados. Igualmente é feita uma sucinta abordagem sobre as principais técnicas analíticas que foram utilizadas: reologia fundamental, calorimetria diferencial de varrimento, microscopia eletrónica de varrimento e espectroscopia de infravermelho médio. No capítulo II apresenta-se o isolamento dos amidos das seis variedades de milho crioulo e a sua caracterização junto com um amido comercial usado como modelo de comparação. Os amidos apresentaram genericamente características físicoquímicas semelhantes e o amido extraído das variedades crioulas MT e MPA 01 apresentaram menor temperatura de gelatinização e maior percentagem de retrogradação, respetivamente. Os efeitos da adição da quitosana e de três galactomananas (goma guar, goma de alfarroba e goma cassia) em sistemas mistos com o amido são analisados nos Capítulos III e IV respetivamente. A adição dos biopolímeros aos amidos resultou no aumento das temperaturas de gelatinização, na alteração da retrogradação do amido pelas galactomananas e na alteração das propriedades viscoeláticas dos géis formados. Os dados de infravermelho esclareceram que nos sistemas com quitosana, o amido formou complexos com o ácido acético usado para dissolver a quitosana e que esta por sua vez formou acetato de quitosana. O comportamento durante a gelatinização do amido comercial quando comparado com o amido do milho crioulo MPA na sua interação com as galactomananas é diferenciado.

Environmental effect on sunflower oil quality.

Sunflower is one of the most important oilseed crops and produces a high-quality edible oil. Balance of fatty acids in standard sunflower oil shows preponderance of linoleic rather than oleic acid, and conditions during seed development, such as temperature, changes the oleic/linoleic ratio of the oil. This work aimed to evaluate the environmental effect on fatty acid profile in a group of standard and high oleic varieties and hybrids. Seeds were produced during regular season crop and during off-season crop featuring different temperatures from anthesis to maturity. Fatty acid composition was determined by gas chromatography. Levels of oleic acid, in standard oil genotypes, raised as the crop developed in warmer environment while levels of linoleic acid decreased, and the opposite was observed when the crop was grown under lower temperature. High oleic genotypes were less sensitive to environment switching and showed lower variation on fatty acid composition.

Analyzing urban green adaptation opportunities: concepts, approaches, & strategies for existing neighborhoods

Over the last decades, the growing evidence of human-caused climate change has raised awareness of the consequences of exceeding global temperature by 2˚C. This awareness has led to a contemporary approach to the conceptualization and management of green adaptation policies in spatial planning. This thesis aims to develop a comprehensive methodology for assessing the adaptability of existing neighborhoods to green strategies. The reliability of the proposed method is examined in the cities of Bologna and Imola and proved to be applicable in other geoghraphical locations. This thesis integrates three key themes of conceptual and implementation principles for urban green adaptation. This thesis initially defines methods for narrowing uncertainties in urban planning energy forecasting modeling by exploring the roles of integrated energy planning. The second is by exploring green retrofitting strategies in building, this thesis examines the effects of various energy-saving factors in roofing scenarios including a green roof, rooftop greenhouse, and insolated roof. Lastly, this thesis analyzes green strategies in urban spaces to enhance thermal comfort through facing urban heat exposure related to urban heat island effects. The roles of integrated energy policies and green strategic thinking are discussed to highlight various aspects of green adaptation on the neighborhood scale. This thesis develops approaches by which cities can face the challenges of current green urban planning and connect the conceptual and practical aspects of green spatial planning. Another point that this thesis highlight is that due to the interdependency of individuals and places, it is difficult to assure whether all the adaptation policies on a large scale are enhancing the resiliency of the neighborhood or they are simply shuffling the vulnerability through the individuals and places. Besides, it asserts that neglecting to reflect on these reallocations of the effects generates serious complications, and will result in long-term dysfunctional consequences.

Coupled wellbore-reservoir simulation of thermal effects during multiphase CO2 injection

T2Well-ECO2M is a coupled wellbore reservoir simulator still under development at Lawrence Berkeley National Laboratory (USA) with the ability to deal with a mixture of H2O-CO2-NaCl and includes the simulation of CO2 phase transition and multiphase flow. The code was originally developed for the simulation of CO2 injection into deep saline aquifers and the modelling of enhanced geothermal systems; however, the focus of this research was to modify and test T2Well-ECO2M to simulate CO2 injection into depleted gas reservoirs. To this end, the original code was properly changed in a few parts and a dedicated injection case was developed to study CO2 phase transition inside of a wellbore and the corresponding thermal effects. In the first scenario, the injection case was run applying the fully numerical approach of wellbore to formation heat exchange calculation. Results were analysed in terms of wellbore pressure and temperature vertical profiles, wellhead and bottomhole conditions, and characteristic reservoir displacement fronts. Special attention was given to the thorough analysis of bottomhole temperature as the critical parameter for hydrate formation. Besides the expected direct effect of wellbore temperature changes on reservoir conditions, the simulation results indicated also the effect of CO2 phase change in the near wellbore zone on BH pressure distribution. To test the implemented software changes, in a second scenario, the same injection case was reproduced using the improved semi-analytical time-convolution approach for wellbore to formation heat exchange calculation. The comparison of the two scenarios showed that the simulation of wellbore and reservoir parameters after one year of continuous CO2 injection are in good agreement with the computation time to solve the time-convolution semi-analytical reduced. The new updated T2Well-ECO2M version has shown to be a robust and performing wellbore-reservoir simulator that can be also used to simulate the CO2 injection into depleted gas reservoirs.