Chemistry of potassium halides and their role in corrosion in biomass and waste firing

Compared to the use of traditional fossil fuels (coal, oil, natural gas), combustion of biomass and waste fuels has several environmental and economic advantages for heat and power generation. However, biomass and waste fuels might contain halogens (Cl, Br, F), alkali metals (Na, K) and heavy metals (Zn, Pb), which may cause harmful emissions and corrosion problems. Hightemperature corrosion occurs typically on furnace waterwalls and superheaters. The corrosion of the boiler tube materials limits the increase of thermal efficiency of steam boilers and leads to costly shutdowns and repairs. In recent years, some concerns have been raised about halogen (Cl, Br, and F)-related hightemperature corrosion in biomass- and waste-fired boilers. Chlorine-related high-temperature corrosion has been studied extensively. The presence of alkali chlorides in the deposits is believed to play a major role in the corrosion observed in biomass and waste fired boilers. However, there is much less information found in literature on the corrosion effect of bromine and fluorine. According to the literature, bromine is only assumed to play a role similar to chlorine; the role of fluorine is even less understood. In this work, a series of bubbling fluidized bed (BFB) bench-scale tests were carried out to characterize the formation and sulfation behaviors of KCl and KBr in BFB combustion conditions. Furthermore, a series of laboratory tests were carried out to investigate the hightemperature corrosion behaviors of three different superheater steels (10CrMo9-10, AISI 347 and Sanicro 28) exposed to potassium halides in ambient air and wet air (containing 30% H2O). The influence of H2O and O2 on the high-temperature corrosion of steels both with and without a salt (KCl) in three gas atmospheres (2% H2O-30% O2-N2, 2% H2O-2% O2-N2 and 30% H2O-2% O2-N2) was also studied. From the bench-scale BFB combustion tests, it was found that HBr has a clearly higher affinity for the available K forming KBr than HCl forming KCl. The tests also indicated that KCl has a higher tendency for sulfation than KBr. From the laboratory corrosion tests in ambient air (also called “dry air” in Paper III and Paper IV), it was found that at relatively low temperatures (≤ 550 °C) the corrosivity of KBr and KF are similar to KCl. At 600 °C, KF showed much stronger corrosivity than KBr and KCl, especially for 10CrMo9-10 and AISI 347. When exposed to KBr or KF, 10CrMo9-10 was durable at least up to 450 °C, while AISI 347 and Sanicro 28 were durable at least up to 550 °C. From the laboratory corrosion tests in wet air (30% H2O), no obvious effect of water vapor was detected at 450 °C. At 550 °C, the influence of water vapor became significant in some cases, but the trend was not consistent. At 550 °C, after exposure with KBr, 10CrMo9-10 suffered from extreme corrosion; after exposure with KF and KCl, the corrosion was less severe, but still high. At 550 °C, local deep pitting corrosion occurred on AISI 347 and Sanicro 28 after exposure with KF. Some formation of K2CrO4 was observed in the oxide layer. At 550 °C, AISI 347 and Sanicro 28 suffered from low corrosion (oxide layer thickness of < 10 μm) after exposure with KBr and KCl. No formation of K2CrO4 was observed. Internal oxidation occurred in the cases of AISI 347 with KBr and KCl. From the laboratory corrosion tests in three different gas atmospheres (2% H2O-30% O2-N2, 2% H2O-2% O2-N2 and 30% H2O-2% O2-N2), it was found that in tests with no salt, no corrosion occurred on AISI 347 and Sanicro 28 up to 600 °C in both the “O2-rich” (2% H2O-30% O2-N2) and “H2O-rich” (30% H2O-2% O2-N2) gas atmospheres; only 10CrMo9-10 showed increased corrosion with increasing temperature. For 10CrMo9-10 in the “O2-rich” atmosphere, the presence of KCl significantly increased the corrosion compared to the “no salt” cases. For 10CrMo9-10 in the “H2O-rich” atmosphere, the presence or absence of KCl did not show any big influence on corrosion. The formation of K2CrO4 was observed only in the case with the “O2-rich” atmosphere. Considering both the results from the BFB tests and the laboratory corrosion tests, if fuels containing Br were to be combusted, the corrosion damage of superheaters would be expected to be higher than if the fuels contain only Cl. Information generated from these studies can be used to help the boiler manufacturers in selecting materials for the most demanding combustion systems.

Writing Violence: the legal, moral and aesthetic Implications of creative non-fiction.

This essay began as a hybrid critical/creative paper that was presented as part of an all-female panel discussing the intersections between writing and extreme violence. My own paper was on the relationship between my creative nonfiction novel The Museum of Atheism and the real life murder of six-year-old beauty queen, JonBenet Ramsey. This essay is an attempt to represent the writing process of the creative nonfiction author, and to consider the ways in which critical theory can be used to highlight, or conversely obscure, fictional writing. In addition to considering the effect of using a real story, a true crime, as the basis for a semi-fictional work, this essay will also consider the relationship I had as a writer to my publisher, editor and agent, and their interventions in the writing process to ensure that facts were deliberately skewed or warped in order to avoid litigation. Finally, I will consider my own relationship to the material, and the impact that this had on the writing process.

Crime and Punishment.

The study of Victorian crime and punishment is a rich area of research that has attracted the interest not only of literary scholars but also of social historians, legal historians, and criminologists. Related scholarship therefore often situates itself at the intersection of traditional disciplinary boundaries, facilitating interdisciplinary conversation. Crime and punishment was a pressing issue for the Victorians and provoked a wealth of responses from contemporaneous commentators in literature, culture, and science. As a new phase of industrialization brought immense wealth for some and abject poverty for others, Victorian urban centers in particular were afflicted by crime. Without an effective system of social welfare in place, social inequality and deprivation drove women, men, and children into petty crime and more serious offenses, resulting in severe punishment ranging from incarceration via penal transportation to hanging. Public executions, not abolished until 1868, attracted huge crowds of spectators, including authors such as Charles Dickens and William Thackeray, who wrote about these experiences. A forerunner of the popular press, street literature conveyed and illustrated these events for a broad audience. Execution broadsides of famous cases, printing the alleged last lamentations of convicts on the scaffold in verse, are estimated to have sold by the million. As the legal system was undergoing reform (comprising changes in legal evidence procedure, divorce law, women’s property rights, and punishment for sexual offenses, for example), sensational trials caused furor and stimulated commentary in literature and the media. Crime and punishment was discussed in a range of literary and popular genres, poetry, and reformist writing. The “Newgate School” of fiction was accused of glamorizing crime, and the popular penny dreadfuls were feared to corrupt public morals. Sensational fiction in the 1860s, which often drew on real-life criminal cases and newspaper reports, depicted the supposedly respectable middle-class family home as a center of transgression. Similarly, detective fiction typically focused on crime in the world of the middle classes. For the student new to the subject of crime and punishment, this area’s interdisciplinary nature can pose an initial challenge.

Recurrent gallstone ileus: case report and literature review

The gallstone ileus is a rare complication of cholelithiasis and it represents the 1-4% of small intestinal mechanical obstruction. Gallstone is generally wedged in the terminal ileum, even if unusual locations have been described. The literature reports a very high morbidity and mortality, often because misdiagnosis or delayed diagnosis. There is no unique opinion in literature about the choice between one-stage and two-stage surgery. We report a clinical case that summarizes the diagnostic and therapeutic difficulties of gallstone ileus.

Giant cell tumor of tendon sheath: study of 64 cases and review of literature

The giant cell tumor of tendon sheath (GCTTS) is the most common benign neoplasm in the hand after the ganglion cyst. Several hypotheses were formulated about the etiological factors of these tumors, but still there is not a common opinion on etiology, prognostic factors and recurrence rate. This article presents a review of literature of the last 15 years about GCTTS to assess the demographic, clinical and histological profile. We compared the information obtained from literature with our experience of 64 cases between 2000 and 2012. Our study showed similar results to those reported in literature, except for the recurrence rate: only 3 cases (4.7%) of 64 patients reported recurrence (versus about 15% on average in literature). Among the various possible factors that predispose to recurrence, it is necessary that the surgeon ensures complete excision of the tumor and removal of any residual satellite nodules. Although the marginal excision is the treatment of choice, it is often difficult to perform due to for the location and the strict adherence of the tumor to the tendon or neurovascular bundles. We used in all cases a magnifying loupe to help a careful research of satellite lesions and to respect surrounding structures.

'Day number': a promoter routine of flexibility and conceptual understanding

This paper is part of the Project “Adaptive thinking and flexible computation: Critical issues”. In this paper we discuss different perspectives of flexibility and adaptive thinking in literature. We also discuss the idea of proceptual thinking and how this idea is important in our perspective of adaptive thinking. The paper analyses a situation developed with a first grade classroom and its teacher named the day number. It is a daily activity at the beginning of the school day. It consists on to look for the date number and to think about different ways of writing it using the four arithmetic operations. The analyzed activity was developed on March 19, so the challenge was to write 19 in several ways. The data show the pupils’ enthusiasm and their efforts to find different ways of writing the number. Some used large numbers and division, which they were just starting to learn. The pupils presented symbolic expressions of 19, decomposing and recomposing it in a flexible manner.

SPINNING NARRATIVES ACROSS POLITICAL DIVIDES: HARNESSING THE CULTURAL POWER OF A STORY WELL-TOLD

This dissertation explores how two American storytellers, considered by many in their to be exemplary in their craft, rely on narrative strategies to communicate to their audiences on divisive political topics in a way that both invokes feelings of pleasure and connection and transcends party identification and ideological divides. Anna Quindlen, through her political columns and op-eds, and Aaron Sorkin, through his television show The West Wing, have won over a politically diverse fan base in spite of the fact that their writing espouses liberal political viewpoints. By telling stories that entertain, first and foremost, Quindlen and Sorkin are able to have a material impact on their audiences on both dry and controversial topics, accomplishing that which 19th Century writer and activist Harriet Farley made her practice: writing in such a way to gain the access necessary to “do good by stealth.” This dissertation will argue that it is their skilled use of storytelling elements, which capitalize on the cultural relationship humans have with storytelling, that enables Quindlen and Sorkin to achieve this. The dissertation asks: How do stories shape the beliefs, perspectives, and cognitive functions of humans? How do stories construct culture and interact with cultural values? What is the media’s role in shaping society? What gives stories their power to unite as a medium? What is the significance of the experience of reading or hearing a well-told story, of how it feels? What are the effects of Quindlen’s and Sorkin’s writing on audience members and the political world at large? What is lost when a simplistic narrative structure is followed? Who is left out and what is overlooked? The literature that informs the answers to these questions will cross over and through several academic disciplines: American Studies, British Cultural Studies, Communication, Folklore, Journalism, Literature, Media Studies, Popular Culture, and Social Psychology. The chapters will also explore scholarship on the subjects of narratology and schema theory.

The Mary Carleton narratives, 1663-1673, a missing chapter in the history of the English novel,

The singular life and curious biographies of Mary Carleton.--The Carleton publications of 1663.--The minor publications of 1673.--"The counterfeit lady," a fiction.--The narrative technique of "The counterfeit lady."--The historical significance of "The counterfeit lady."--The current doctrine of the rise of the English novel.--Bibliographical difficulties.

Coupling of magnetic, strain and electric polarization fields in the structure of multiferroic material

The comprehensive study on the coupling of magnetism, electrical polarization and the crystalline lattice with the off-stoichiometric effects in self-doped multiferroic hexagonal h-LuMnxO3±δ (0.92≤x≤1.12) ceramic oxides was carried out for the PhD work. There is a complex coupling of the three ferroic degrees. The cancelation of the magnetic moments of ions in the antiferromagnetic order, electric polarization with specific vortex/antivortex topology and lattice properties have pushed researchers to find out ways to disclose the underlying physics and chemistry of magneto-electric and magneto-elastic couplings of h-RMnO3 multiferroic materials. In this research work, self-doping of Lu-sites or Mn-sites of h-LuMnxO3±δ ceramics prepared via solid state route was done to pave a way for deeper understanding of the antiferromagnetic transition, the weak ferromagnetism often reported in the same crystalline lattices and the ferroelectric properties coupled to the imposed lattice changes. Accordingly to the aim of the PhD thesis, the objectives set for the sintering study in the first chapter on experimental results were two. First, study of sintering off-stoichiometric samples within conditions reported in the bibliography and also extracted from the phase diagrams of the LuMnxO3±δ, with a multiple firings ending with a last high temperature step at 1300ºC for 24 hours. Second, explore longer annealing times of up to 240 hours at the fixed temperature of 1300 ºC in a search for improving the properties of the solid solution under study. All series of LuMnxO3±δ ceramics for each annealing time were characterized to tentatively build a framework enabling comparison of measured properties with results of others available in literature. XRD and Rietveld refinement of data give the evolution the lattice parameters as a function to x. Shrinkage of the lattice parameters with increasing x values was observed, the stability limit of the solid solution being determined by analysis of lattice parameters. The evolution of grain size and presence of secondary phases have been investigated by means of TEM, SEM, EDS and EBSD techniques. The dependencies of grain growth and regression of secondary phases on composition x and time were further characterized. Magnetic susceptibility of samples and magnetic irreversibility were extensively examined in the present work. The dependency of magnetic susceptibility, Neel ordering transition and important magnetic parameters are determined and compared to observation in other multiferroics in the following chapter of the thesis. As a tool of high sensitivity to detect minor traces of the secondary phase hausmannite, magnetic measurements are suggested for cross-checking of phase diagrams. Difficulty of previous studies on interpreting the magnetic anomaly below 43 K in h-RMnO3 oxides was discussed and assigned to the Mn3O4 phase, with supported of the electron microscopy. Magneto-electric coupling where AFM ordering is coupled to dielectric polarization is investigated as a function of x and of sintering condition via frequency and temperature dependent complex dielectric constant measurements in the final chapter of the thesis. Within the limits of solid solubility, the crystalline lattice of off-stoichiometric ceramics was shown to preserve the magneto-electric coupling at TN. It represents the first research work on magneto-electric coupling modified by vacancy doping to author’s knowledge. Studied lattices would reveal distortions at the atomic scale imposed by local changes of x dependent on sintering conditions which were widely inspected by using TEM/STEM methods, complemented with EDS and EELS spectroscopy all together to provide comprehensive information on cross coupling of distortions, inhomogeneity and electronic structure assembled and discussed in a specific chapter. Internal interfaces inside crystalline grains were examined. Qualitative explanations of the measured magnetic and ferroelectric properties were established in relation to observed nanoscale features of h-LuMnxO3±δ ceramics. Ferroelectric domains and topological defects are displayed both in TEM and AFM/PFM images, the later technique being used to look at size, distribution and switching of ferroelectric domains influenced by vacancy doping at the micron scale bridging to complementary TEM studies on the atomic structure of ferroelectric domains. In support to experimental study, DFT simulations using Wien2K code have been carried out in order to interpret the results of EELS spectra of O K-edge and to obtain information on the cation hybridization to oxygen ions. The L3,2 edges of Mn is used to access the oxidation state of the Mn ions inside crystalline grains. In addition, rehybridization driven ferroelectricity is also evaluated by comparing the partial density of states of the orbitals of all ions of the samples, also the polarization was calculated and correlated to the off-stoichiometric effect.

Transfrontalité et perméabilité dans les genres de non-fiction : l’essai et la chronique

Partiendo de la noción de literatura de pensamiento, como conjunto heterogéneo y complejo de formas literarias con vocación argumentativa, el estudio que sigue pretende mostrar a la vez el valor paradigmático del ensayo, en el marco de estas escrituras, y la naturaleza transfronteriza de los géneros de no-ficción, entre los cuales el ensayo y la crónica periodística constituyen dos de las formas más próximas. En un primer momento, se analizan los rasgos característicos del ensayo, tal como Montaigne lo concibió, con el fin de determinar las líneas de fuerza de esta forma matricial, de la que procede hasta hoy toda una tradición de escritos asistemáticos y porosos de naturaleza personal y reflexiva. En un segundo momento, se estudian los rasgos específicos de la crónica periodística contemporánea, a la luz del modelo canónico, poniendo el énfasis en la perspectiva subjetiva de la mirada y en la noción de actualidad, como principales indicadores de la dimensión permeable e híbrida de este género.

Development of computer application for determination of chemical diffusion properties in biological tissues

The main objective of this work was to develop an application capable of determining the diffusion times and diffusion coefficients of optical clearing agents and water inside a known type of muscle. Different types of chemical agents can also be used with the method implemented, such as medications or metabolic products. Since the diffusion times can be calculated, it is possible to describe the dehydration mechanism that occurs in the muscle. The calculation of the diffusion time of an optical clearing agent allows to characterize the refractive index matching mechanism of optical clearing. By using both the diffusion times and diffusion of water and clearing agents not only the optical clearing mechanisms are characterized, but also information about optical clearing effect duration and magnitude is obtained. Such information is crucial to plan a clinical intervention in cooperation with optical clearing. The experimental method and equations implemented in the developed application are described in throughout this document, demonstrating its effectiveness. The application was developed in MATLAB code, but the method was personalized so it better fits the application needs. This process significantly improved the processing efficiency, reduced the time to obtain he results, multiple validations prevents common errors and some extra functionalities were added such as saving application progress or export information in different formats. Tests were made using glucose measurements in muscle. Some of the data, for testing purposes, was also intentionally changed in order to obtain different simulations and results from the application. The entire project was validated by comparing the calculated results with the ones found in literature, which are also described in this document.

Up-Link/Down-Link capacity Unbalance analysis in UMTS using a GIS based Planning Tool and MATLAB simulation

Capacity analysis using simulation is not a new thing in literature. Most of the development process of UMTS standardization have used simulation tools; however, we thing that the use of GIS planning tools and matrix manipulation capacity of MATLAB can show us different scenarios and make a more realistic analysis. Some work is been doing in COST 273 in order to have more realistic scenarios for UMTS planning. Our work initially was centered in uplink analysis, but we are now working in downlink analysis, specifically in two areas: capacity in number of users for RT and NRT services, and Node B power. In this work we will show results for up-link capacity and some results for downlink capacity and BS power consumption.

Changes in catches and biological characteristics of Nile tilapia (Oreochromis niloticus Linnaeus) in Lake Wamala (Uganda) under changing climatic conditions

There have been changes in catches and biological characteristics of the Nile Tilapia, Oreochromis niloticus (Linnaeus) in Lake Wamala (Uganda) since its introduction and establishment, but the factors which have contributed to these changes are not adequately understood. This study examined changes in catches and biological characteristics of Nile tilapia in relation to changes in temperature, rainfall and lake depth to provide an understanding of the role of changing climatic conditions. There was an increase in minimum, maximum and average temperature since 1980, but only minimum (0.021ºCyr-1) and average (0.018ºCyr-1) showed a significant trend (p < 0.05). Rainfall increased by 8.25 mmyr-1 since 1950 and accounted for 79.5% of the water input into the lake while evaporation accounted for 86.2% of the water loss from the lake. The lake depth was above 4 m during the years rainfall was above normal average of 1180 mm, except during the period 2011-2014. The contribution of Nile tilapia to total catch and CPUE changed with rainfall and lake depth up to 2000, after which they decreased despite increase in rainfall. There was a strong positive correlation between lake depth and average total length of Nile tilapia (r = 0.991, p < 0.001) and length at 50% maturity (r = 0.726, p < 0.001). The length-weight allometry between high and low lake depths was significantly different [t (6) = 3.225, p < 0.05], with Nile tilapia being heavier (for a given length) at high lake depth than at low lake depth. Fecundity of Nile tilapia was higher and egg diameter lower than what is reported in literature. Nile tilapia shifted from algal dominated diet during the wet season to include more insects during the dry season. The study showed that the catches and biological characteristics of Nile tilapia change with climate and hydrological factors and these need to be considered in management of the fisheries of Lake Wamala.

An investigation of the clinical utility of preoperative cardiopulmonary exercise testing in patients undergoing major pancreatic surgery

Pancreaticoduodenectomy with or without adjuvant chemotherapy remains the only modality of possible cure in patients with cancer involving the head of the pancreas and the periampullary region. While mortality rates after pancreaticoduodenectomy have improved considerably over the course of the last century, morbidity remains high. Patient selection is of paramount importance in ensuring that major surgery is offered to individuals who will most benefit from a pancreaticoduodenectomy. Moreover, identifying preoperative risk factors provides potential targets for prehabilitation and optimisation of the patient's physiology before undertaking surgery. In addition to this, early identification of patients who are likely to develop postoperative complications allows for better allocation of critical care resources and more aggressive management high risk patients. Cardiopulmonary exercise testing is becoming an increasingly popular tool in the preoperative risk assessment of the surgical patient. However, very little work has been done to investigate the role of cardiopulmonary exercise testing in predicting complications after pancreaticoduodenectomy. The impact of jaundice, systemic inflammation and other preoperative clinicopathological characteristics on cardiopulmonary exercise physiology has not been studied in detail before in this cohort of patients. The overall aim of the thesis was to examine the relationships between preoperative clinico-pathological characteristics including cardiopulmonary exercise physiology, obstructive jaundice, body composition and systemic inflammation and complications and the post-surgical systemic inflammatory response in patients undergoing pancreaticoduodenectomy. Chapter 1 reviews the existing literature on preoperative cardiopulmonary exercise testing, the impact of obstructive jaundice, perioperative systemic inflammation and the importance of body composition in determining outcomes in patients undergoing major surgery with particular reference to pancreatic surgery. Chapter 2 reports on the role of cardiopulmonary exercise testing in predicting postoperative complications after pancreaticoduodenectomy. The results demonstrate that patients with V˙O2AT less than 10 ml/kg/min are more likely to develop a postoperative pancreatic fistula, stay longer in hospital and less likely to receive adjuvant therapy. These results emphasise the importance of aerobic fitness to recover from the operative stress of major surgery without significant morbidity. Cardiopulmonary exercise testing may prove useful in selecting patients for intensive prehabilitation programmes as well as for other optimisation measures to prepare them for major surgery. Chapter 3 evaluates the relationship between cardiopulmonary exercise physiology and other clinicopathological characteristics of the patient. A detailed analysis of cardiopulmonary exercise test parameters in jaundiced versus non-jaundiced patients demonstrates that obstructive jaundice does not impair cardiopulmonary exercise physiology. This further supports emerging evidence in contemporary literature that jaundiced patients can proceed directly to surgery without preoperative biliary drainage. The results of this study also show an interesting inverse relationship between body mass index and anaerobic threshold which is analysed in more detail in Chapter 4. Chapter 4 examines the relationship between preoperative cardiopulmonary exercise physiology and body composition in depth. All parameters measured at cardiopulmonary exercise test are compared against body composition and body mass index. The results of this chapter report that the current method of reporting V˙O2, both at peak exercise and anaerobic threshold, is biased against obese subjects and advises caution in the interpretation of cardiopulmonary exercise test results in patients with a high BMI. This is particularly important as current evidence in literature suggests that postoperative outcomes in obese subjects are comparable to non-obese subjects while cardiopulmonary exercise test results are also abnormally low in this very same cohort of patients. Chapter 5 analyses the relationship between preoperative clinico-pathological characteristics including systemic inflammation and the magnitude of the postoperative systemic inflammatory response. Obstructive jaundice appears to have an immunosuppressive effect while elevated preoperative CRP and hypoalbuminemia appear to have opposite effects with hypoalbuminemia resulting in a lower response while elevated CRP in the absence of hypoalbuminemia resulted in a greater postoperative systemic inflammatory response. Chapter 6 evaluates the role of the early postoperative systemic inflammatory response in predicting complications after pancreaticoduodenectomy and aims to establish clinically relevant thresholds for C-Reactive Protein for the prediction of complications. The results of this chapter demonstrate that CRP levels as early as the second postoperative day are associated with complications. While post-operative CRP was useful in the prediction of infective complications, this was the case only in patients who did not develop a post-operative pancreatic fistula. The predictive ability of inflammatory markers for infectious complications was blunted in patients with a pancreatic fistula. Chapter 7 summarises the findings of this thesis, their place in current literature and future directions. The results of this thesis add to the current knowledge regarding the complex pathophysiological abnormalities in patients undergoing pancreaticoduodenectomy, with specific emphasis on the interaction between cardiopulmonary exercise physiology, obstructive jaundice, systemic inflammation and postoperative outcomes. The work presented in this thesis lays the foundations for further studies aimed at improving outcomes after pancreaticoduodenectomy through the development of individualised, goal-directed therapies that are initiated well before this morbid yet necessary operation is performed.

Grito vagabundo : el exilio como alegoría de un trauma histórico en tres novelas latino-canadienses

Cette thèse étudie la façon dont trois romans latino-canadiens utilisent le trope de l’exil comme allégorie d’un trauma historique qui comprend plus que l’expérience individuelle de ses protagonistes : la transition forcée de l’État vers le Marché en Amérique latine effectuée par les dictatures. Cobro revertido (1992) de José Leandro Urbina; Le pavillon des miroirs (1994) Sergio Kokis; et Rojo, amarillo y verde (2003) de Alejandro Saravia, explorent divers aspects de ce processus à travers les exercices de mémoire de leurs personnages. L’exil oblige les protagonistes de ces oeuvres à se confronter aux limites des structures sémiotiques par lesquelles ils essaient de donner un fondement idéologique à leur existence sociale. Ils découvrent ainsi qu’il n’est pas possible de reproduire des hiérarchies, des valeurs, ni des relations de pouvoir de leur pays d’origine dans leur pays d’accueil, non seulement à cause des différences culturelles, mais aussi à cause d’un changement historique qui concerne la relation du sujet avec la collectivité et le territoire. Ces œuvres abordent l’expérience de ce changement par un dialogue avec différents genres littéraires comme le roman de fondation, la méta-fiction historique du Boom, le roman de formation et le testimonio, mis en relation avec divers moments historiques, de la période nationale-populaire aux transitions, en passant par les dictatures. Cela permet aux auteurs de réfléchir aux mécanismes narratifs que plusieurs œuvres latino-américaines du XXème siècle ont utilisé pour construire et naturaliser des subjectivités favorables aux projets hégémoniques des États nationaux. Ces exercices méta-narratifs comprennent le rôle de l’écriture comme support privilégié pour l’articulation d’une identité avec le type de communauté imaginaire qu’est la nation. Ils servent aussi à signaler les limites de l’écriture dans le moment actuel du développement technologique des médias et de l’expansion du capitalisme transnational. Ainsi, les auteurs de ces œuvres cherchent d’autres formes de représentation pour rendre visibles les traces d’autres histoires qui n’ont pas pu être incorporées dans le discours historique officiel.