Dissertations / Theses on the topic 'Fragmentation science'

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Political Science, 2010.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. 658-681).
The internal unity and discipline of insurgent groups helps us understand the military effectiveness of armed groups, patterns of violence against civilians, and the ability of insurgent organizations to negotiate and demobilize, but the causes of insurgent cohesion and fragmentation have not been systematically or comparatively examined. This study offers a theory to explain why some armed groups are more cohesive and controlled than others. It argues that the trajectories of insurgent organizations can be substantially explained by focusing on two variables: the structure of the social networks and institutions upon which the organization is built, and the organization's access to material resources from outside the war zone. First, the structure of the core networks upon which an organization is constructed determines the internal social environment of the group: its social base shapes its organizational form. The denser the core networks, and more tightly they pull together local communities, the more robust will be the organization that emerges. Social embeddedness can therefore be more important than mass political popularity, public goods provision, or ideology in providing the basis for enduring organizational cohesion. Organizations built around coalitions of localized pockets of collective action or leaders operating among populations with whom they lack social ties will face severe problems of internal control - regardless of organizational blueprints or ethnic and class appeals. Second, external material support from states and diasporas tends to centralize internal control and to enhance insurgent military power. Rather than encouraging looting and thuggishness, resource-wealth can fuel highly cohesive and disciplined armed organizations. The interaction of social bases and external support generates empirically distinct trajectories of organizational cohesion. Mechanisms explaining change over time are derived from the structural underpinnings of this argument. This theory is tested with a study of 26 armed groups in nine civil wars. The primary research design is a set of within-conflict comparisons of insurgent organizations in civil wars in Kashmir, Northern Ireland, and Sri Lanka. Within each war there is dramatic variation across groups within a shared structural context. Fieldwork, primary sources, and secondary sources are used to trace out the different trajectories of militancy and their origins. An external validity check is provided by a study of Southeast Asia, relying on a cross-national comparison of communist insurgents in Malaya, Vietnam, and the Philippines, a sub-national, cross-conflict comparison of armed groups in Aceh and East Timor, and a within-conflict comparison of separatists in the southern Philippines. These comparisons reveal strong support for the theory relative to its competitors while also uncovering new mechanisms of change and evolution.
by Paul Stephen Staniland.
Ph.D.

During the nineties, Colombia experienced a two-fold process of restructuring. First, the political system underwent a process of constitutional reform in order to strengthen the state and increase its legitimacy, surpass the exclusionary character of the political regime, and achieve greater equity in the distribution of social resources. Second, the economy made the transition from a Keynesian development strategy to a strategy of "opening" or liberalization and internationalization of the economy, in order to increase the economic efficiency by reducing the “size” of the state and its regulatory role. The purpose of this dissertation is to analyze the interplay and contradictions of economic and political factors in the restructuring of the Colombian politico-economic system. The main finding of this dissertation is that the simultaneous adoption of a neoliberal economic strategy and of the Political Constitution of 1991, have had a contradictory relationship: while the “political opening” has produced favorable conditions for fostering programs of democratization and social integration, the “economic opening” has counteracted that possibility given that it implies a social exclusionary process. This tension has aggravated the problems o f political and social integration that have traditionally characterized Colombian society. This crucial tension has also been characteristic o f Latin America in the nineties. However, it has been neglected and undertheorized in most of the democratization studies of American comparative politics. Most of them lack consideration of structural aspects. According to those studies, the cause of regime change is determined by the strategic elections of actors. Contrary to these approaches, I develop a structural perspective. I consider that social phenomena are partly determined by structural factors, and scientific research should, assign them decisive importance, since a fundamental basis for social action and transformation is to be found in the dynamics o f relationships between individuals and structures and the development of contradictions within structures.

Thesis: Ph. D., Massachusetts Institute of Technology, Department of Political Science, May, 2020
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 260-279).
Political science research devotes considerable attention to the impact of political risk on multinational companies' (MNCs') behavior. However, this body of research suffers from two main oversights: (1) a disproportionate focus on MNCs' investment decisions, and (2) an assumption that political risk takes a common, centralized form across countries. In this dissertation, I redirect, attention to the political determinants of MNCs' supply chain linkages. I argue that these linkages represent a risk-mitigating strategy for MNCs, and one that is particularly well suited for dealing with environments where the sources of political risk are spread throughout the state apparatus -- which I refer to as fragmented political risk. To test this theory, I draw on both cross-sectional survey data of MNCs in Sub-Saharan Africa and firm-level panel data from Indonesia -- a country that experienced a profound fragmentation in the structure of political risk. The principal finding of this research is that fragmented political risk causes MNCs to increase their use of local suppliers, with particularly strong effects among those that are (1) more vulnerable to political risk, and (2) have a greater capacity to adopt linkages, in general. These findings qualify research on the political determinants of FDI by showing that MNCs, and not merely states, are capable of resolving political risk in the host country.
by Nicholas Intscher.
Ph. D.
Ph.D. Massachusetts Institute of Technology, Department of Political Science

This research showed that data and events involving alliance formation and political fragmentation in the Arab world and particularly the Gulf Cooperation Council (GCC) from 1945-1990 were not treated sufficiently in the general theoretical works surveyed. A host of new propositions dealing with the dichotomy of alliances and their fragmentation are contributed herein to the body of general knowledge regarding alliance formation. The eleven categories of hypotheses, from the most represented in the literature to the least, dealt with national attributes, war and alliances, economic systems, political fragmentation, balance of power, foreign aid, bandwagoning strategy, integrative process, gaming and alliances, balance of threats, and chain-gang and buck-passing strategies. Using the GCC as a case study, a total of 145 propositions were examined; 45 (31%) were operationalized. The national attributes category was the most applicable followed by balancing strategies, indicating that commonality among states and expediency are essential to GCC alliance formation. Whereas war and alliances is the next important category in the literature, balance of threats is more applicable because GCC members are disadvantaged in their military capabilities. A balancer was required to protect the status quo, a role which was fulfilled by the United States. Economic variables are fairly represented in the theoretical operationalization, indicating that the Arab Gulf states were utility maximizers. They employed oil, their sole significant collective good, to fulfill national objectives, internally as well as externally. In addition, the six states were among the leading countries in their gifts of economic aid. But the relationship between aid and alliance formation in the Gulf exhibits a stronger association with other states in the world, not among themselves. The GCC is an elitist undertaking, as measured by the high level of summits and ministerial meetings, with little popular participation and a lack of citizen contribution to the progress of the organization. This, in effect, slowed down the integrative process, which was the ultimate objective behind the creation of the Council. While political feuds and territorial claims have threatened to fragment the Council, the framers' overriding concerns about security and self-preservation have acted as unifying factors, guaranteeing the endurance of the GCC alliance to date.

Thesis (PhD)--Stellenbosch University, 2004.
ENGLISH ABSTRACT: The study presented in this dissertation had as primary aim to develop pathways to heterogeneous aqueous polymerizations that had living characteristics. To this end, the reversible addition fragmentation chain transfer (RAFT) process was investigated in predispersed and ab initio emulsions as well as homogeneous media. The synthesis of RAFT agents was carried out. The compounds prepared provided varied behaviour in reaction. In situ IH nuclear magnetic resonance (NMR) increased understanding of homogeneous RAFT mediated polymerizations. The early behaviour of RAFT mediated polymerizations led to the definition of initialization; a period before pre-equilibrium in a polymerization where degenerate behaviour occurs. Stable miniemulsion preparation methods were developed that provided living polymer latexes using high surfactant concentrations. The effect of surfactant concentration on particle size and latex stability was investigated. Living polymer characteristics were shown by the use of size exclusion chromatography, and 2- dimensional chromatography conclusively showed block polymer formation. In situ NMR spectroscopy of emulsions in deuterated water was used to provide evidence on the role of initiator solubility in polymerization. Secondary nucleation in high surfactant concentration miniemulsions systems was investigated using both particle size and molar mass analysis techniques and a means of eliminating secondary particle nulceation was shown through the use of aqueous phase radical traps. The role of the RAFT agent used in the polymerization was shown to be significant in determining the extent to which multiple polymer distributions formed in the polymerization in that radical exit from particles was affected. Finally, a new form of emulsion polymerization, which has been termed proto-seeded emulsion, has been developed. The proto-seed latex is formed by using a monomer whose polymer has chain length dependent water solubility. This process allows ab initio RAFT mediated emulsion polymerization to be conducted successfully without transport of RAFT agents in heterogeneous media.
AFRIKAANSE OPSOMMING: Die primerê doel in hierdie dissertasie is die ontwikkeling van roetes na heterogene water-gebaseerde polimerisasies met lewende eienskappe. Om hierdie doel te bereik is die omkeerbare addisie fragmentasie ketting oordrag proses (eng reversible addition fragmentation chain transfer (RAFT)) ondersoek in vooraf verspreide en direkte emulsies sowel as homogene media. Die sintese van RAFT agente is uitgevoer. Die verbindings wat voorberei is het verskillende einskappe in reaksies getoon. In situ IH kern magnetiese resonansie (KMR) het die kennis en begrip van homogene RAFT polimerisasies uitgebrei. Die vroeë gedrag van RAFT polimerisasies het tot die definisie van inisialisasie gelei; 'n periode voor die pre-ekwilibrium in 'n polimerisasie waartydens "degenerate" gedrag plaasvind. Stabiele miniemulsie voorbereidings metodes is ontwikkel wat lewende polimeer latekse verskaf het met gebruik van hoë seep konsentrasies. Die effek van seep konsentrasie op partikel grootte en lateks stabilitiet is ondersoek. Lewende polimeer eienskappe is bewys deur gebruik te maak van grootte-uitsluiting vloeistof chromatografie, en 2-dimensionele chromatografie het duidelik blok-polimeer vorming gewys. In situ KMR spektroskopie van emulsies in gedeutereerde water is gebruik om bewys te lewer van die rol van initieerder-oplosbaarheid in polimerisasie. Sekondêre nukleasie in hoë seep konsentrasie miniemuisie sisteme is ondersoek met die gebruik van beide partikel grootte sowel as molêre massa analise tegnieke. 'n Metode om sekondêre partikels te verhoed is verskaf deur gebruik te maak van waterfase radikaal lokvalle. Die rol van die RAFT agent in die polimeerisasie is beduidend in die graad van vorming van meer as een polimeer distribusie in die sin dat radikal uitgang van partikels beinvloed was. Ten slotte is 'n nuwe vorm van emulsie polimeerisasie ontwikkel wat proto-gesaaide emulsie genoem is. Die proto-gesaaide lateks is gevorm deur gebruik te maak van 'n monomeer waarvan die polimeer water-oplosbaarheid afhanklik is van die kettinglengte. Die proses laat ab initio RAFT emulsie polimerisasie toe om suksesvol uitgevoer te word sonder die vervoer van RAFT agente in heterogene media.

Thesis (PhD)--Stellenbosch University, 2004.
ENGLISH ABSTRACT: To comply with the ever growing demands for materials with better properties and complex architectures, polymer chemistry has resorted to the use of living free radical polymerization techniques. Despite the structural control some of these techniques offer, major disadvantages do exist. For example, most require ultra-pure reagents, hence only a small fraction of the monomers used in industry can be polymerized in this way. This rendered these new living techniques less advantageous from a commercial point of view. Recently, a revolutionary new living free radical process, namely the reversible addition-fragmentation chain transfer process, or RAFT process, was developed that combines the control over the polymer produced with the robustness and versatility of a free radical process. However, the RAFT process is not without its problems. In some dithioester mediated polymerizations, significant inhibition and rate retardation effects have been observed. Two main opposing opinions have been proposed in recent literature to explain these phenomena observed. The main point of difference between these two groups is the fate of the formed intermediate RAFT radicals, i.e., slow fragmentation of the formed intermediate radicals together with possible reversible intermediate RAFT radical termination, or fast fragmentation of the formed intermediate radicals together with possible irreversible intermediate RAFT radical termination. Between these opposing two groups, there is a difference of six orders of magnitude for the rate of fragmentation of the formed intermediate RAFT radicals. The work presented in this thesis is an attempt to clarify some of the mysteries, i.e., inhibition and rate retardation observed in some RAFT polymerizations. Experimental evidence to support or contradict the theories of the above mentioned two opposing groups was investigated. The concentration-time evolution of the intermediate radical concentration (cy), for styrene and butyl acrylate polymerizations mediated by cumyl dithiobenzoate (COB) at 70°C and 90 °C, was followed via in situ electron spin resonance spectroscopy (ESR). The concentration-time evolution profiles observed were ascribed to the formation of very short chains during the early stages of the reaction. It was also found that the RAFT process is not particularly sensitive to oxygen. The intermediate and propagating radical (cp) concentrations (and their ratio) for the cumyl dithiobenzoate mediated styrene polymerizations were examined by ESR spectroscopy and kinetics. The system showed strong chain length effects in kinetics, assuming all chains were of similar number average molar mass (Mn). However, unusual behavior with respect to existing mechanistic knowledge was observed in other aspects of the system. The central equilibrium "constant" (Keq) was found to be dependent on both temperature and initial reactant concentrations. The observed intermediate radical concentrations were not consistent with predictions based on existing literature models. It was also found that the time dependence of the intermediate radical concentration varies significantly with the type of RAFT agent used. Unexpectedly, intermediate radicals were detected at very long reaction times in the virtual absence of initiator, enhancing the belief of possible reversible termination reactions involving the intermediate radicals. An extra radical (nonpropagating or intermediate) species was observed (via ESR spectroscopy) to form during some reactions. Its concentration increased with time. The combination of data from several analytical techniques provided evidence for the formation of dead chains by the termination of intermediate radicals in the free radical polymerization of styrene, mediated by a cumyl dithiobenzoate RAFT agent, at 84°C. Experiments done focused on the early stages of the reactions, targeting very low final number average molar mass values, with high initiator concentrations. The formation of these terminated chains did not occur to a significant extent until a large fraction of the chains reached a degree of polymerization greater than unity. This corresponded to the occurrence of a maximum in intermediate radical concentration. In situ 1H nuclear magnetic resonance (NMR) and electron spin resonance spectroscopy was used to directly investigate the processes that occur during the early stages (typically the first few monomer addition steps) of an AIBN-initiated reversible addition fragmentation chain transfer polymerization of styrene, in the presence of a cyanoisopropyl dithiobenzoate and cumyl dithiobenzoate RAFT agent, at 70°C and 84 °C respectively. 1H NMR spectroscopy allowed the investigation of the change in concentration of important dithiobenzoate species as a function of time. Identification and concentrations of the radicals present in the system could be inferred from corresponding ESR spectroscopy data. An apparent "inhibition" effect was observed in both the cyanoisopropyl and cumyl dithiobenzoate mediated polymerizations. This effect could be reduced by increasing the reaction temperature to 84 °C. However, the use of cumyl dithiobenzoate as RAFT agent prolonged this effect. This apparent "inhibition" effect was attributed to selective fragmentation of the formed intermediate radicals during the early stages of the reaction, and to different propagation rate coefficients (kp) of the resulting (different) radicals. A change in the equilibrium coefficient for the systems investigated was ascribed to possible progressively decreasing addition and fragmentation rate coefficients of propagating and intermediate radicals formed during the reaction. The increase in intermediate radical concentration, and thus possible intermediate radical termination, was shown to also be a probable cause of the rate retardation observed in the RAFT mediated systems investigated. To conclude, probable causes of the observed inhibition and rate retardation in some dithiobenzoate mediated systems were investigated. It was found that intermediate RAFT radical termination does occurs, albeit reversibly or irreversibly. A maximum in the intermediate radical concentration, and thus possible intermediate radical termination, was seen to occur during the observed rate retardation. An apparent inhibition effect observed was ascribed to a possible change in termination kinetics, the formation of terminated intermediate radical products and a rapidly changing kp of the propagating radicals.
AFRIKAANSE OPSOMMING: Om te voldoen aan die ewig groeiende aanvraag vir materiale met beter eienskappe en komplekse samestellings, is in die polimeerchemie lewende vry-radikaal polimerisasietegnieke ontwikkel. Ten spyte van die feit dat party van die polimerisasie tegnieke die strukuur van die gevormende polimere kan beheer, bestaan daar tog nadele. Die meeste polimerisasie tegnieke benodig ultra suiwer reagense, dus kan net 'n klein fraksie van die monomere wat deur die industrie gebruik word op so 'n manier gepolimeriseer word. Dus, vanuit 'n komersieële oogpunt, is die nuwe lewende polimerisasietegnieke minder voordelig. Onlangs is 'n revolusionere nuwe lewende vry-radikaal polimerisasieproses, naamlike die RAFT-(eng. reversible addition-fragmentation chain transfer process) proses ontwikkel, wat die beheer oor die geproduseerde polimere, kombineer met die robuustheid en veelsydigheid van 'n vry-radikaalproses. Die RAFT proses is egter nie sonder probleme nie. Beduidende inhibisie en vertraging van die polimerisasie tempo is in sommige dithioester-bemiddelde polimerisasies opgemerk. Daar is hoofsaaklik twee opponerende opinies oor die redes vir die inhibisie en vertragings effekte. Die grootste verskil tussen die twee groepe lê in die lot van die gevormde intermediêre radikaal, m.a.w. stadige fragmentasie van die gevormende intermediêre radikale tesame met moontlike onveranderlike intermediêre radikaalterminasie, of vinnige fragmentasie tesame met moontlike omkeerbare intermediêre radikaalterminasie. Tussen die twee groepe, is daar 'n verskil van ses ordegrotes vir die groote van die tempo van fragmentasie van die gevormende intermediêre radikaal. Die werk wat in die tesis weergee word, is 'n poging om sommige van die geheime van die RAFT proses, m.a.w. inhibisie en vertraging van die polimerisasietempo, op te los. Die ondersoek was gerig op eksperimetele bewyse om die teorieë van die twee opponerede groepe of te bevestig of teen te spreek. Die konsentrasie tyd-verandering van die intermediêre radikaal konsentrasie vir stireen- en butielakrilaatpolimerisasie, bemiddeled deur CDB (eng cumyl dithiobenzoate) by 70 oe and 90 oe, is gevolg deur middel van in situ (lat. vir in die oorspronklike plek, m.a.w. binne-in die ESR masjien) elektronspin-resonans (ESR) spektroskopie. Die vorm van die konsentrasie tyd-profiele is toegeskryf aan die vorming van baie kort polimeerkettings gedurende die vroeë reaksietye. Dit is ook bepaal dat die RAFT-proses nie besonder sensitief was vir suurstof nie. Die intermediêre en die propagerende radikaalkonsentrasie (en hulle verhouding) vir die CDB bemiddelde stireen polimerisasies, is bepaal deur middel van elektronspin-resonans spektroskopie en die kinetika van die sisteem. Die kinetika van die sisteem toon 'n sterk afhanklikheid teenoor die lengte van die polimeerkettings, as aanvaar word dat al die kettings dieselfde numeriese gemiddelde molêre massa het. Des nieteenstaande, is egter onverwagte gedrag in ander aspekte van die sisteem opgemerk. Dit was ook gevind dat die sentrale ewewigs-"konstante" (Keq) afhanklik was van die temperatuur en die oorspronklike reaktant konsentrasie. Die bepaalde intermediêre radikaalkonsentrasie het verskil van voorspelde waardes gebaseer op literatuur modelle. Dit is ook gevind dat die intermediêre radikaalkonsentrasie afhanklik is van die tipe RAFT agent wat in die polimerisasie reaksies gebruik word. Intermediêre radikale is onverwags gevind na baie lang reaksietye, wanner verwag is dat die konsentrasie van die afsetter, en dus ook die intermediêre radikale, baie klein sou wees. Dit het die verwagting dat omkeerbare intermediêre radikaalterminasie kan plaasving, versterk. 'n Ekstra radikale spesie, wat gedurende die reaksie vorm en waarvan die konsentrasie groter word met tyd, is ook deur ESR-spektroskopie geidentifiseer. 'n Kombinasie van verskillende skeikundige tegnieke is gebruik om bewyse te kry vir die vorming van dooie kettings wat ontstaan deur middel van intermediêre radikale terminasiereaksies, in die vry-radikaalpolimerisasie van stireen, wat deur 'n CDB RAFT-agent bemiddeled word by 84°C. Eksperimente is gedoen om die reaksie tydens vroeë reaksietye te ondersoek. Baie hoë afsetter konsentrasies is ook gebruik, wat tot uiters lae numeriese gemiddelde molêre massas van die polimeerkettings gelei het. Beduidende konsentrasies van die dooie kettings is eers gevind nadat 'n graad van polimerisasie van groter as een bereik is. Dit het ooreengestem met 'n maksimum in die konsentrasie van die intermediêre radikale. In situ 1H kern magnetiese-resonans (KMR) en electronspin-resonans spektroskopie was gebruik om 'n RAFT proses, wat gedurende die vroeë reaksie tye (tipies gedurende die eerste paar monomeer toevoegingstappe) te bestudeer, wat deur AIBN (eng azo bis(isobutyronitrile)) afgeset word en bestaan uit stireen en CIDB (eng cyanoisopropyl dithiobenzoate) en CDB RAFT agente onderskeidelik, en by 70°C and 84 °C reageer. 1H KMRspektroskopie was gebruik om die veranderinge in die konsentrasie van die belangrike spesies te bepaal. Die identifikasie en konsentrasie van die radikale kon bepaal word deur middel van ESR data. 'n Skynbare 'inhibisie-effek' is waargeneem in die reaksies wat bemiddeled word deur CIDB en CDB. Die effek is verminder toe die reaksietemperatuur verhoog is na 84°C. Die gebruik van CDB as RAFT agent het egter die effek vergroot. Die skynbare 'inhibisie effek' was toegeskryf aan die selektiewe fragmentasie van die intermediêre radikale gedurende die vroeë reaksietye, en aan verskillende propagasie tempokoëffisiënte (kp) van die verskillende radikale. Die veranderlike sentrale ewewigskoëffisiënte is toegeskryf aan die toevoegings en fragmentasie tempokoëffisiënte van die propagerende en intermediêre radikale wat toenemend afneem. Die is ook getoon dat die toename in die konsentrasie van die intermediêre radikale en dus moontlike intermediêre radikale terminasie, 'n oorsaak kan wees van die vertraging van die polimerisasietempo in die RAFT-bemiddelde reaksies. Ter samevatting, die waarskynlike oorsake vir inhibisie en die polimerisasietempo vertraging opgemerk in sekere dithiobenzoaat-bemiddelde sisteme, is ondersoek. Dit was gevind dat intermediêre radikaalterminasie wel kan gebeur, of dit nou omkeerbaar of onveranderlik gebeur. 'n Maksimum in die konsentrasie van die intermediêre radikale, en dus moontlike intermediêre radikaalterminasie, het voorgekom tesame met 'n vertraging in die polimerisasietempo. Die skynbare inhibisie-effek wat opgemerk was kan toegeskryf word aan 'n moontlike verandering in die terminasie kinetika, die formasie van getermineerde intermediêre radikale en 'n vinnig veranderende propagasie tempokoëffisiënt.

Cet ouvrage à pour objet l'analyse des facteurs socio-politiques ayant influence la réorientation des discours officiels entourant la politique canadienne de multiculturalisme au début des années 1990. Tel que dénoté par Houle (1999), les discours du gouvernement fédéral touchant directement ou indirectement la politique canadienne de multiculturalisme au cours des années 1990 furent caractérisés par l'importance accordée au partage de valeurs communes et à l'unité nationale. Selon le gouvernement fédéral, cette réorientation des discours aurait visé à corriger les incompréhensions des Canadiens vis-à-vis de la nature véritable du multiculturalisme et à apaiser les inquiétudes des Canadiens croyant que la politique canadienne de multiculturalisme permette aux minorités ethnoculturelles de ne pas s'intégrer aux valeurs de la société canadienne. Une analyse statistique des résultats de l'enquête sur les attitudes multiculturelles et ethniques des Canadiens de 1991 vise à étudier les deux éléments de cette affirmation, à savoir l'inquiétude des Canadiens à l'endroit des conséquences de la politique canadienne de multiculturalisme et la non-intégration effective des minorités ethnoculturelles aux valeurs dites "canadiennes." (Abstract shortened by UMI.)

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1997.
Includes bibliographical references (leaves 110-111).
by Jung-Taik Hwang.
M.Eng.

Thesis (MSc)--Stellenbosch University, 2001.
ENGLISH ABSTRACT: A novel approach to conducting controlled free radical polymerization in aqueous systems using Reversible Addition-Fragmentation Chain Transfer (RAFT) has been studied. When conducting RAFT in aqueous systems, reaction conditions must be chosen such that monomer transport across the aqueous-phase is either eliminated or facilitated. This is to prevent the formation of the red layer associated with RAFT in emulsions. The formation of the red layer is ascribed to the inability of waterinsoluble, dithiobenzoate-endcapped oligomers to be sufficiently transported across the aqueous phase. The novel approach in this study focussed on eliminating monomer transport and comprises two fundamental steps: the synthesis of dithiobenzoate-encapped oligomers in bulk followed by miniemulsification of these oligomers to yield a polymerizable miniemulsion. Dithioesters that act as chain transfer agents in the RAFT -process were synthesized in situ, thereby eliminating laborious and time-consuming organic purification procedures of dithioesters. In situ formation of the RAFT-agents involved conducting the reaction between di(thiobenzoyl) disulfide and conventional azo-initiators of differing structures in the presence of monomer. The structure of the chosen azo-initiator played a role in the efficiency of the RAFT process when the reaction was conducted in the presence of monomer to control the free radical polymerization process. Synthesis of the oligomers was performed by heating di(thiobenzoyl) disulfide and a selected azo-initiator, in the presence of monomer for a specific reaction duration in bulk. After the reaction was stopped, these oligomers were then miniemulsified by adding water, surfactant and cosurfactant, followed by the application of shear to form the resulting mini emulsion. The free radical polymerization of the dithiobenzoate-endcapped oligomers in the miniemulsion proceeded in a controlled manner with molecular weight increasing in a linear fashion with increasing conversion, while polydispersities remained low. The familiar red layer formation associated with RAFT polymerization in conventional emulsions was not observed under these conditions. The effects of changing the cosurfactant (hydrophobe) as well as changing the degree of polymerization of the emulsified oligomers were also investigated and described.
AFRIKAANSE OPSOMMING: Hierdie studie is geloods om 'n nuwe benadering tot die beheerde vry-radikaal polimerisasie in water gebaseerde sisteme te ondersoek. Daar is spesifiek gekyk na die uitvoer van die RAFT (Reversible Addition-Fragmentation Chain Transfer) proses in emulsies. Wanneer RAFT in emulsies toegepas word, moet die toestande waaronder die reaksie uitgevoer word, versigtig opgestel word. Die toestande moet so gekies word dat die vervoer van monomere deur die waterfase óf geëlimineer word óf gefasiliteer word. Dit word gedoen om die faseskeiding in die vorm van 'n rooi laag, wat so kenmerkend van RAFT -polimerisasie in emulsies is, te voorkom. Hierdie faseskeiding vind plaas omdat die vervoer van ditiobensoaat endgroep-bevattende oligomere deur die waterfase tydens interval II, moeilik is a.g.v. hulle oplosbaarheid in water. Die nuwe benadering wat hier bestudeer is, het twee basiese stappe. Eerstens word die ditiobensoaat endgroep-bevattende oligomere in bulk gesintetiseer. Dit word gevolg deur die emulsifisering van die oligomere. Hierna vind verdere polimerisasie van die oligomere plaas deur die dormante oligomere te heraktiveer. Die ditio-esters wat as kettingoordrag agente optree in die RAFT proses, word in situ gesintetiseer. Hierdie modifikasie sny tydrowende organiese suiweringsmetodes uit. Die in situ RAFT agente word gesintetiseer deur di(tiobensoïel) disulfied met verskillende konvensionele azo-inisieerders te laat reageer. Die struktuur van die spesifieke azoinisieerder het wel 'n rol gespeel in die effektiwiteit van die RAFT proses om molekulêre massa te beheer as bg. reaksie in die teenwoordigheid van monomere uitgevoer is. Die sintese van die oligomere is gedoen deur di(tiobensoïel) en 'n azo-inisieerder te verhit in die teenwoordigheid van monomere. Die reaksie is gedoen in bulk en die graad van polimerisasie van die oligomere is beheer deur die reaksie te stop by verskillende tydstippe. Nadat die bulk reaksie gestop is, is hierdie oligomere ge-emulsifiseer deur die oligomere te meng met 'n seep, hidrofoob en water. Hierdie mengsel word dan onderwerp aan 'n vermengingskrag om 'n polimeriseerbare mini-emulsie te vorm. Die voortsetting van die polimerisasie van die oligomere in die mini-emulsie het op 'n beheerde wyse verloop, m.a.w. molekulêre massa wat linieêr toeneem met stygende omsetting. Polidispersiteit indekse van die polimere het deurentyd laag gebly in die stabielste sisteme. Onder hierdie toestande was daar geen kenmerkende rooi laagvorming te bespeur nie. Die effekte wat die verandering van die hidrofoob, asook die verandering van die graad van polimerisasie van die oligomere op die sisteem gehad het, is onder andere ook ondersoek en beskryf.

Thesis (MSc)--Stellenbosch University, 2000.
ENGLISH ABSTRACT: This work involves the study of the effects of Reversible Addition-Fragmentation Chain Transfer (RAFT) agents on the emulsion polymerization of styrene. The feasibility of RAFT as a method for obtaining controlled radical polymerizations in emulsion systems is also investigated. Both seeded and ab initio systems were studied with three RAFT agents of varying structure. Inhibition and retardation effects on addition of various amounts of the RAFT agents to the emulsion systems were observed and the trends noticed. The effect of the RAFT agents on the average number of radicals per latex particle was calculated from reaction rates. The effect of the RAFT agent on the molecular weight and the molecular weight distribution was monitored by gel permeation chromatography. Exit of free radicals from the latex particles proves to be a major feature in the studied RAFT emulsion systems. Fragmentation of the RAFT agent in the latex particles, gives rise to free radical species that can exit from the particle and enter other particles where they can either terminate instantaneously or propagate. The exit and termination processes presumably result in both the inhibition and retardation of the emulsion polymerizations. A linear increase in Mn with conversion is observed, however the low concentration of RAFT agent in the latex particles is responsible for the obtained number average molecular weights being much higher than predicted. The low concentrations of RAFT agents in the latex particles is also responsible for the broad molecular weight distributions that are obtained. Reaction conditions for RAFT experiments should to be chosen so that the effects of exit processes are minimized and that the RAFT agent is primarily situated in the latex particles. These conditions must be met if the RAFT process is to be successful as a method of controlled radical polymerization in emulsions.
AFRIKAANSE OPSOMMING: Hierdie navorsing behels die studie van die effek van In bygevoegde addisie-fragmentasie kettingsoordragsreagent (RAFT1) op die emulsie polimerisasie van stireen. Die uitvoerbaarheid van RAFT as 'n metode om gekontroleerde radikale polimerisasies in emulsiesisteme te verkry is ook ondersoek. Eksperimente met drie RAFTkettingoordragsreagente van gevarieerde strukture is uitgevoer in beide seeded en ab initia sisteme. Die effek van die RAFT-reagent op die inhibisie en vertraging van die emulsie polimerisasie is waargeneem en die invloed van RAFT op die gemiddelde aantal radikale per partikel is bepaal. Die ontwikkeling van die molekulêre massa en die molekulêre massadistribusie is waargeneem deur middel van gel permeasie- kromatografiese tegnieke. Die ontsnapping van vrye radikale vanuit die partikels was 'n belangrike faktor in RAFT emulsiesisteme wat ondersoek is. Hierdie radikale is gegenereer deur die fragmentasie van die oorspronklike RAFT-reagent. Fragmentasie van die RAFT-reagent in die lateks partikels lei tot die vorming van vrye radikale spesies wat uit een partikel kan ontsnap en ander partikels kan binnedring waar dit onmiddellik kan termineer of propageer. Die ontsnappings- en terminasieprosesse van vrye radikale lei oënskynlik tot die inhibering en vertraging van die emulsie polimerisasie. 'n Lineêre verhoging in die gemiddelde molekulêre massa tydens konversie is waargeneem, alhoewel die Mn-waardes baie hoër was as wat verwag is. Die verskil kan toegeskryf word aan die klein hoeveelhede van die RAFT-reagent wat in die partikels teenwoordig is. Hierdie lae RAFT-konsentrasies is ook verantwoordelik vir die breë molekulêre massa distribusie wat waargeneem is. Vir die RAFT-proses om suksesvol te wees in gekontroleerde radikale polimerisasies in emulsies, moet reaksie kondisies so gekies word dat die ontsnapping van vrye radikale tot 'n minimum beperk word en die RAFT-reagent hoofsaaklik in die lateks partikels teenwoordig is.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Political Science, 1991.
Includes bibliographical references (leaves 276-334).
by Richard Hyland Phillips.
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Political Science, 1991.

Since the 1980s, the American federal government has devolved a wide array of crucial policy decisions - from transportation to welfare initiatives - to the state and local levels. With a decrease in federal aid and an increase in the number of tools available to lower tiers of government, scholars of American urban politics have suggested that cooperation among metropolitan jurisdictions could help address critical political and policy challenges, including inequities in municipal resources and unfettered suburban sprawl. This dissertation argues that metropolitan political segregation|that is, geographically-based political divisions - represents a serious obstacle to these partnerships and remains poorly understood. This project thus has two goals: to explain variations in metropolitan political segregation and explore their consequences for regional coalition-building. I first present a theory connecting America's unique racial geography to political segregation. I contend that racially segregated metropolitan areas with large minority population concentrations will experience more political segregation than their more homogenous peers. These political divisions will in turn hinder coalition-building surrounding critical metropolitan policies. Marshaling 1988 and 2000 precinct-level electoral data for every metropolitan area in the country, I find that racial demographics almost exclusively explain variations in political segregation, with more racially segregated, heavily black and Latino metropolitan areas exhibiting greater geographic political divisions. These rifts in turn have a potent impact on metropolitan policy outcomes. Taking advantage of an array of qualitative and quantitative data on mass transportation and affordable housing policy-making, I discover that greater political segregation constrains metropolitan coalition-building and spurs more fragmented policy outcomes. These findings have a disturbing implication: those regions with concentrated pockets of poverty - places most in need of metropolitan cooperation in the contemporary, heavily localized political climate - are the least able to forge partnerships around shared local policy goals.

Impact phenomena shaped our solar system. From the accretion of the planetesimals 4.6 billion years ago to the comparatively recent spallations of meteorites from their parent bodies, which take them to Earth, this ceaseless process has left no bit of solid matter untouched. As usual for most solar system processes, the scales are far different than we can address directly in the laboratory. Impact velocities are often much higher than we can achieve, sizes are often vastly larger, and most impacts take place in an environment where the only gravitational force is self-gravity. Laboratory studies, by contrast, are limited to disruptive impacts with typical velocities ∼3 km/s, involving targets smaller than a kilogram in an imposed terrestrial gravitational environment. We must extrapolate from these data by twenty orders of magnitude before we reach the mass range of asteroids, comets and planetesimals. The complexity of fragmentation phenomena, and the role both strength and gravity play in most interesting catastrophic impacts, make numerical models of catastrophic disruption the most viable research tools. But numerical models must be subject to careful scrutiny regarding numerical accuracy and the proper representation of physics. For this reason two very different code models of fragmentation and catastrophic disruption are presented here. They not only are both good predictors of laboratory outcomes, but they also largely agree about predictions involving large-scale extrapolation. A simple analytical model for fragment size distributions in the strength regime is also presented. Each of these models is suited to a particular class of problem, depending on the complexity and the sophistication required. It is hoped that the ideas and models developed in these pages will contribute to a better understanding of fracture and fragmentation events with regard to the evolution of solar systems and planets.

This thesis studies the positions of the political groups in the European Parliament by examining the debates, focusing on the question of migration and more specifically on the policy of relocation of migrants. With the increasing number of people migrating into Europe, migration is an important question to study in the context of the European Union. The European Parliament consists of 200 different national parties composed in eight different political groups trying to agree upon common policies for legislation, which makes the political battle taken place in the Parliament even more interesting.    This thesis seeks to describe the positions of the groups within the Parliament by using dimensions and categories of state security vs. human security and EU-integration vs. state sovereignty. The study finds that a majority of the party groups in the Parliament emphasises further integration, however there is a more evident difference between seeing the issue of migration as a state security or a human security matter between the political groups. These findings are interesting, demonstrating that even in a sensitive issue as migration, related to states’ sovereignty, a majority seems to emphasise cooperation between states, indicating that further cooperation may be taken in other policy areas as well.    Key words: European Union, European Parliament, European integration, Migration, Security, Securitization, Human security, Human rights, State sovereignty, Dimension analysis.

Les entrepôts de données XML forment une base intéressante pour les applications décisionnelles qui exploitent des données hétérogènes et provenant de sources multiples. Cependant, les Systèmes de Gestion de Bases de Données (SGBD) natifs XML actuels présentent des limites en termes de volume de données gérable, d'une part, et de performance des requêtes d'interrogation complexes, d'autre part. Il apparaît donc nécessaire de concevoir des méthodes pour optimiser ces performances.

Pour atteindre cet objectif, nous proposons dans ce mémoire de pallier conjointement ces limitations par fragmentation puis par répartition sur une grille de données. Pour cela, nous nous sommes intéressés dans un premier temps à la fragmentation des entrepôts des données XML et nous avons proposé des méthodes qui sont à notre connaissance les premières contributions dans ce domaine. Ces méthodes exploitent une charge de requêtes XQuery pour déduire un schéma de fragmentation horizontale dérivée.

Nous avons tout d'abord proposé l'adaptation des techniques les plus efficaces du domaine relationnel aux entrepôts de données XML, puis une méthode de fragmentation originale basée sur la technique de classification k-means. Cette dernière nous a permis de contrôler le nombre de fragments. Nous avons finalement proposé une approche de répartition d'un entrepôt de données XML sur une grille. Ces propositions nous ont amené à proposer un modèle de référence pour les entrepôts de données XML qui unifie et étend les modèles existants dans la littérature.

Nous avons finalement choisi de valider nos méthodes de manière expérimentale. Pour cela, nous avons conçu et développé un banc d'essais pour les entrepôts de données XML : XWeB. Les résultats expérimentaux que nous avons obtenus montrent que nous avons atteint notre objectif de maîtriser le volume de données XML et le temps de traitement de requêtes décisionnelles complexes. Ils montrent également que notre méthode de fragmentation basée sur les k-means fournit un gain de performance plus élevé que celui obtenu par les méthodes de fragmentation horizontale dérivée classiques, à la fois en terme de gain de performance et de surcharge des algorithmes.

American cities have proliferated in the post-War era. More than 2,000 new cities were founded between 1950 and 2000. While the history of the local government boom has been documented, research into urban fragmentation has explored why there is no consolidation of metropolitan areas rather than exploring why Americans chose fragmentation initially. This dissertation proposes that individuals create new jurisdictions because individuals prefer to have governments which give them the services individuals desire, even if they could have similar (but not perfect) services cheaper in a larger jurisdiction. Individuals, however, must balance the benefit they get from better fitting cities with the price they must pay to live within the small cities. In the first part of the dissertation, I synthesize the literatures on urban governance and fragmentation with the literature on interest groups. This synthesis builds the argument for conceiving cities as interest groups and contributes a theory of urban behavior as the behavior of organized interest groups. I argue that urban fragmentation should exist anywhere there are urban areas –not only metropolises –and that fragmentation is produced by diversity in the population and constrained by the resources available for the formation of cities. In the second part of the dissertation, I analyze the fragmentation of both metropolitan and non-metropolitan areas to determine what drives fragmentation. I use Poisson regression on 2-period panel data from 1992 and 2002 collected from various public sources. I find that there are differences in the forms of fragmentation in the metropolis and the non-metropolis. In both types of urban settlement, fragmentation is driven by political and population diversity and available resources for forming cities. Legal authority and intergovernmental revenue are particularly important. Finally, I turn my attention to cities’ interactions with each other. I use a survey of Kentucky mayors, fielded with the Kentucky League of Cities, to determine why mayors of different cities to communicate with each other. Using specialized network methods I find that mayor-to-mayor contact is not based on goal and interest similarities as expected, but rather depends on sharing an organization which encourages communication –an Area Development District.

L'actine est une protéine abondante dans le cytosquelette des eucaryotes qui se polymérise pour former des filaments. Ces filaments jouent un rôle fondamental dans de nombreux processus biologiques (contraction musculaire, division et motilité cellulaire, etc...). La dynamique d'assemblage et de désassemblage des filaments est sous le contrôle de plusieurs protéines associées à l'actine, en particulier l'ADF/cofiline. Cette protéine s'associe aux filaments et les fragmente, accélérant ainsi le désassemblage du cytosquelette d'actine. Au cours de cette thèse, nous avons développé des modèles mathématiques pour étudier l'effet de l'ADF/cofiline sur le cytosquelette d'actine. Dans un premier temps, nous nous sommes intéressés à la cinétique d'assemblage des filaments en présence d'ADF/Cofiline. Des simulations basées sur l'algorithme de Gillespie ont mis en évidence un équilibre dynamique dans lequel la polymérisation des filaments est contrebalancée par la fragmentation. Nous avons pu caractériser cet équilibre et comparer nos prédictions à des données in vitro obtenues dans le cadre d'une collaboration avec l'équipe de Laurent Blanchoin (CEA/iRTSV/LPCV, Grenoble). Dans un second temps, nous nous sommes penchés sur la mécanique des polymères d'actine pour expliquer les bases physiques de la fragmentation. Un modèle mésoscopique du filament a permis de prouver l'existence d'un couplage entre les déformations en flexion et en torsion dans le filament. Ce couplage permet de convertir les fluctuations thermiques en un effort qui cisaille la section du filament, entraînant ainsi la fragmentation. Les résultats extraits de ces modèles ont donc permis d'améliorer notre compréhension de l'action d'ADF/cofiline sur le cytosquelette d'actine.

Dynamic memory management required by allocation-intensive (i.e., Object Oriented and linked data structured) applications has led to a large number of research trends. Memory performance due to the cache misses in these applications continues to lag in terms of execution cycles as ever increasing CPU-Memory speed gap continues to grow. Sophisticated prefetcing techniques, data relocations, and multithreaded architectures have tried to address memory latency. These techniques are not completely successful since they require either extra hardware/software in the system or special properties in the applications. Software needed for prefetching and data relocation strategies, aimed to improve cache performance, pollutes the cache so that the technique itself becomes counter-productive. On the other hand, extra hardware complexity needed in multithreaded architectures decelerates CPU's clock, since "Simpler is Faster." This dissertation, directed to seek the cause of poor locality behavior of allocation--intensive applications, studies allocators and their impact on the cache performance of these applications. Our study concludes that service functions, in general, and memory management functions, in particular, entangle with application's code and become the major cause of cache pollution. In this dissertation, we present a novel technique that transfers the allocation and de-allocation functions entirely to a separate processor residing in chip with DRAM (Intelligent Memory Manager). Our empirical results show that, on average, 60% of the cache misses caused by allocation and de-allocation service functions are eliminated using our technique.

Civil wars are inherently complex and often feature a myriad of actors, whose interactions influence the intensity, duration and outcome of the conflict. The larger the number of actors involved in a conflict, the more complex it gets. While civil wars are often portrayed as a dyadic interaction between the government and a single rebel group, this is far from the reality. Between 1946 and 2015, more than half of those countries that experienced civil wars saw two or more active rebel groups. Understanding multiparty conflicts better is important, as they are deadlier, more difficult to solve and more dangerous for civilians. This dissertation studies the causes and consequences of multiparty civil wars. It suggests that all actors in a conflict system with several actors influence each other, which impacts conflict dynamics. Four essays shed light on different aspects of these civil wars. Essay I studies the differences in formation rates of rebel groups across the states of Northeast India. It finds that potential rebel groups will only form when rebellion is perceived as a legitimate way to address grievances and when competition from already existing groups is not too high. Essay II looks at rebel group splintering: It focusses on relationships within rebel groups and finds that both vertical and horizontal relations affect the likelihood of splintering. Essay III studies violent interactions between rebel groups and investigates how different conflict dynamics influence interrebel fighting. It demonstrates that interrebel fighting is more likely when one of the rebel groups is more successful against the government and when negotiations are ongoing. Finally, Essay IV widens the scope of conflict actors by studying why rebels decide to fight against UN peacekeeping operations. It shows that only relatively strong rebel groups are likely to attack blue helmets. Taken together, this dissertation furthers our understanding of the causes and consequences of multiparty civil wars. It highlights the intricate web of relations that form between actors and that influence civil war dynamics. These relations matter not only for studying civil wars, but also for preparing negotiations or planning a peacekeeping mission.

Les sociologues des sciences "antidifférenciationnistes" annoncent ou décrivent l'effacement des frontières entre science et industrie. La figure archétypale de cette nouvelle science hétéronome serait le "chercheur-entrepreneur", imprégné d'un "esprit d'entreprise" qui lui permettrait de mieux communiquer avec le monde marchand, idée que l'on retrouve sous la forme d'une doxa dans certains discours politiques. Cet antidifférenciationnisme, très proche du constructivisme social, repose sur une radicalité épistémologique fort controversée qui s'offre en réponse aux échecs du fondationnalisme. L'objet de ce travail est de penser l'autonomie de la science en neutralisant les querelles métaphysiques qui découlent de cette radicalité. Il débouche sur la production d'une série de concepts que je mobilise pour l'analyse d'une enquête menée auprès de 81 chercheurs créateurs d'entreprises (complétée par une série d'études de cas), ce qui m'amène à nuancer les thèses antidifférenciationnistes.

Thesis (DSc)--Stellenbosch University, 2012.
ENGLISH ABSTRACT: Examples of the use of NMR spectroscopy in the study of radical polymerization processes have been described. The studies presented have made a significant contribution to the understanding of the fundamental mechanistic processes in these polymerization systems. It is pointed out that NMR in conventional radical polymerization is of limited use due to the concurrent occurrence of all elementary reactions (initiation, propagation and termination). Conversely, for living radical polymerization, NMR has great value. In that case, the elementary reactions are somewhat more restricted to specific times of the polymerization process. This allows for example the detailed study of the early stages of chain growth in Reversible Addition-­‐Fragmentation Chain Transfer (RAFT) mediated polymerization. Two different studies are described. The first is related to the early stages of RAFT-­‐mediated polymerization. A process for which we coined the name initialization was studied via in situ 1H NMR spectroscopy. It is shown that in many cases, there is a selective reaction that converts the original RAFT agent into its single monomer adduct. A few different examples and their mechanistic interpretation are discussed. It is also shown that NMR spectroscopy can be a valuable tool for the assessment of a RAFT agent in conjunction with a specific monomer and polymerization conditions. In the second study, 15N NMR, 31P NMR and 1H NMR are used for two different types of experiments. The first is a conventional radical copolymerization in which the growing chains are trapped by a 15N labeled nitroxide to yield a stable product. In the second experiment, a similar copolymerization is conducted under nitroxide-­‐mediated conditions. The nitroxide of choice contains phosphorous, which enables the quantification of the terminal monomer in the dormant chains. Each of the experiments individually provides interesting information on conventional radical copolymerization and nitroxide-­‐mediated copolymerization, respectively. Combination of the experimental data reveals an interesting discrepancy in the ratio of terminal monomer units in active chains and dormant chains. Although not unexpected, this result is interesting and useful from a mechanistic as well as a synthetic point of view. In terms of future perspectives, it is expected that the advanced analytical techniques as described here will remain crucial in polymer science. Present developments in radical polymerization, such as investigations into monomer sequence control, rely on accurate knowledge of kinetic and mechanistic details of elementary reactions. It is expected that such detailed studies will be a main challenge for the next decade of polymer research.
AFRIKAANSE OPSOMMING: Voorbeelde van die gebruik van KMR-­‐spektroskopie in die studie van radikaalpolimerisasies word beskryf. Hierdie studies het ʼn beduidende bydrae gelewer tot die verstaan van die fundamentele meganistiese prosesse in hierdie polimerisasiesisteme. Dit het daarop gewys dat KMR beperkte gebruike het in konvensionele radikaalpolimerisasies as gevolg van die gelyktydige voorkoms van alle basiese reaksies (afsetting, voortsetting en beëindiging). Aan die anderkant het KMR groot waarde vir lewende radikaalpolimerisasie. In hierdie geval is die elementêre reaksies ietwat meer beperk tot spesifieke tye van die polimerisasieproses. Gedetailleerde studies kan byvoorbeeld van die vroeë stadiums van die kettinggroei in Omkeerbare Addisie-­‐Fragmentasie-­‐ KettingOordrag (OAFO)-­‐bemiddelde polimerisasie gedoen word. Twee verskillende studies is beskryf. Die eerste het betrekking op die vroeë stadiums van die OAFO-­‐bemiddelde polimerisasie. 'n Proses wat “inisialisering” genoem is, is bestudeer deur middel van in situ 1H KMR-­‐spektroskopie. Dit is bewys dat daar in baie gevalle 'n selektiewe reaksie is wat die oorspronklike OAFO-­‐agent in sy enkelmonomeeradduk verander voor polimerisasie. 'n Paar ander voorbeelde en hul meganistiese interpretasie is bespreek. Dit is ook bewys dat KMR-­‐spektroskopie 'n waardevolle hulpmiddel kan wees vir die assessering van 'n OAFO-­‐agent in samewerking met 'n spesifieke monomeer en polimerisasie toestande. In die tweede studie is 15N KMR, 31P KMR en 1H KMR gebruik vir twee verskillende tipes van die eksperiment. Die eerste is 'n konvensionele radikaalkopolimerisasie waarin die groeiende kettings vasgevang word deur 'n 15N-­‐gemerkte nitroksied om 'n stabiele produk te lewer. In die tweede eksperiment is 'n soortgelyke kopolimerisasie gedoen onder nitroksied-­‐ bemiddelde toestande. Die gekose nitroksied bevat fosfor wat die kwantifisering van die terminale monomeer in die dormante kettings moontlik maak. Elkeen van die individuele eksperimente lewer interessante inligting oor konvensionele radikale kopolimerisasie en nitroksied-­‐bemiddelde kopolimerisasie, onderskeidelik. ʼn Kombinasie van die eksperimentele data toon 'n interessante verskil aan in die verhouding van die terminale monomeereenhede in die aktiewe en sluimerende kettings. Alhoewel dit nie onverwags is nie, is die resultate interessant en van waarde vanuit 'n meganistiese-­‐ sowel as 'n sintetiese oogpunt. In terme van toekomstige perspektiewe word daar verwag dat gevorderde analitiese tegnieke soos hier beskryf, belangrik sal bly in polimeerwetenskap. Huidige ontwikkelinge in radikaalpolimerisasie, soos ondersoeke na die beheer van monomeervolgorde, maak staat op akkurate kennis van kinetiese en meganistiese besonderhede van die basiese reaksies. Daar word verwag dat sulke gedetailleerde studies ʼn uitdaging sal bied vir die volgende dekade van polimeernavorsing.

Made available in DSpace on 2016-12-23T14:36:48Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-10-24
The Homo Oeconomics society, which actions react from the market laws and the cartesian ideas, is often criticized by us. It is the society that is oriented by the spheres of legality, of morality and of all fights in favor of survival. This paper is a humanist denounce of philosophical, scientific and political aspect in favor of life. It explains how the process of fragmentation of Knowledge and scientific, legitimised by the public politics, happens in this moral society that does not favor ethics. Based on that, we defend the necessity of the resurrection of ethics, according to Spinoza, for the construction of a society made by the development of man s potential capacities that are still castrated by the sciences and governmental politics. The economic dictatorship promoted by the race to growth and development has hindered man to be in the center of these politics, propagating states of misery and social chaos.
Criticamos a sociedade do Homo Oeconomicus, cujas ações regem-se pelas leis do mercado e pelo pensamento cartesiano. É a sociedade que se orienta pelas esferas da legalidade, da moralidade e de todas as lutas em favor da sobrevivência. O trabalho é uma denúncia humanista, de cunho filosófico, científico e político, em favor da vida. Explicamos como o processo de fragmentação do conhecimento e das ciências, legitimado pelas políticas públicas, engendram-se nessa sociedade moral que não favorece a ética. Defendemos, com isso, a necessidade da ressurreição da ética, a partir de Spinoza, para a construção de uma sociedade formada pelo desenvolvimento das capacidades potenciais do homem que ainda são castradas pelas ciências e pelas políticas governamentais. A ditadura econômica promovida pela corrida ao crescimento e ao desenvolvimento tem impedido que o homem esteja no centro dessas políticas, perpetuando estados de misérias e caos social.

Il tema dell’unità/unificazione della scienza è radicato nella storia e nella teoria dell’epistemologia del XX secolo. Il presente lavoro riprende tale tema e lo applica alla psicologia in generale e alla psicologia clinica in particolare, con un approccio sia teorico sia empirico. In particolare, la discussione sulla frammentazione della psicologia ha radici nella riflessione filosofica relativa all’unità o pluralità del metodo scientifico e a temi contigui, quali il linguaggio scientifico, le leggi e gli oggetti d’indagine della scienza. In questa cornice di riferimento, viene analizzato dettagliatamente il fenomeno della frammentazione della psicologia tramite l’esposizione critica delle proposte avanzate nella letteratura per la sua unificazione. Quindi, vengono evidenziati alcuni problemi centrali che riguardano diversi livelli di analisi, da quello socio-istituzionale a quello metodologico, in riferimento alla psicologia generale e alla psicologia clinica. E’ entro questo scenario che si situa la ricerca empirica, realizzata al fine di esplorare la rappresentazione emozionale della disciplina, in quanto scienza e professione, da parte degli psicologi italiani. La comparazione tra la disamina teorica e i risultati della ricerca empirica portano a concludere che per la psicologia è fondamentale riappropriarsi di quegli strumenti concettuali che possano meglio coordinare i rapporti tra dati, teorie e applicazioni pratiche.
The issue of the unity/unification of science has its roots in the history and theory of 20th Century epistemology. The present research addresses this issue and implements it in psychology and in clinical psychology, with both a theoretical and empirical approach. In particular, the topic of the fragmentation of psychology is connected to the philosophical reflection regarding the unity or plurality of the scientific method and to contiguous issue as the scientific language, the laws and science’s objects of interest. Within such a framework, the phenomenon of psychology’s fragmentation is examined in detail through the critical analysis of the proposals proposed in the unification literature. Then, some key problems regarding different levels of analysis, from socio-institutional to methodological, are highlighted, with regards to general psychology and clinical psychology. In this scenario, the empirical research is aimed to explore the emotional representations of Italian psychologist about their own discipline, as a science and as a profession. The comparison between the theoretical examination and the outcomes of the empirical research lead to the conclusion that is crucial for psychology to manage those conceptual tools which are able to better coordinate the relationships between data, theories and practical applications.

In a world where authoritarian states are taking a bigger place in the global arena, it’s important to learn from democracies and how a strong democracy can be upheld. The objective of this essay is to explain how Mongolia, a country with two giant authoritarian geographical neighbors in China and Russia still upholds a strong consolidated democracy. How did Mongolia develop from a history of communism to a free open country? This essay aims to explain Mongolia’s democratization after the collapse of the USSR in 1990 through the national internal factors of Larry Diamonds democratization theory; the development of authoritarian fragmentation and the development of civil society. The result illustrates that the development of authoritarian fragmentation led to competition between the elites, hard-liners vs soft-liners which in turn turned out in liberalization improvements. While the outcome of the development of civil society led to mobilization, protests and manifestations towards change and NGO’s got established which in turn lead to liberal reforms and economic improvement. The conclusion of the essay argues that the development of authoritarian fragmentation and civil society played a big role in Mongolia’s democratization in the 1990s.

Les sociologues des sciences "antidifférenciationnistes" annoncent ou décrivent l'effacement des frontières entre science et industrie. La figure archétypale de cette nouvelle science hétéronome serait le "chercheur-entrepreneur", imprégné d'un "esprit d'entreprise" qui lui permettrait de mieux communiquer avec le monde marchand, idée que l'on retrouve sous la forme d'une doxa dans certains discours politiques. Cet antidifférenciationnisme, très proche du constructivisme social, repose sur une radicalité épistémologique fort controversée qui s'offre en réponse aux échecs du fondationnalisme. L'objet de ce travail est de penser l'autonomie de la science en neutralisant les querelles métaphysiques qui découlent de cette radicalité. Il débouche sur la production d'une série de concepts que je mobilise pour l'analyse d'une enquête menée auprès de 81 chercheurs créateurs d'entreprises (complétée par une série d'études de cas), ce qui m'amène à nuancer les thèses antidifférenciationnistes
Antidifferenciationnist sociology of science proclaims or describes the collapse of boundaries between science and industry. The archetype of this new heteronomical science would be the "entrepreneur researcher", whose "entrepreneurial spirit" would allow better communication with the economic world. Translated into the political sphere, this idea becomes a common "doxa". In reaction against the failure of foundationalist forms of philosophy, this antidifferenciationnism, often overlapping with social constructivism, relies on a radical and controversial epistemology. The aim of this work is to bypass this kind of metaphysical dispute, in order to permit a fruitful discussion of the question of science's autonomy. I propose several concepts whiçh are then used for analysis of data collected for 81 entrepreneur-researchers (supplemented by case studies). This empirical study demonstrates the limits of antidifferenciationnist theory

La thèse a porté sur l'étude de peptides et d'oligonucléotides par fragmentation dans la source électrospray d'un Quattro II (Micromass). L'instrument a d'abord été évalué en mode positif avec des peptides thioester modèles puis en mode négatif avec des oligodésoxynucléotides bromés dont la fragmentation de la base modifiée permet sa localisation dans la séquence. La fragmentation de peptides acétal et diol (aldéhyde hydraté) conduit à un même ion final cyclique. L'hydratation de peptides aldéhyde a été étudiée en solution par RMN et en phase gazeuse par fragmentation dans la source. Les informations issues de ce travail ont permis une meilleure compréhension du mécanisme de la réaction d'oximation.

Nous visons à travers cette thèse à proposer un ensemble d'approches permettant d'optimiser les entrepôts de données et d'aider l'AED à bien mener cette optimisation. Nos approches d'optimisation reposent sur l'utilisation de trois techniques d'optimisation : la fragmentation horizontale primaire, dérivée et les index de jointure binaires (IJB). Nous commençons par proposer une approche de fragmentation qui prend en considération à la fois la performance (réduction du coût d'exécution) et la manageabilité (contrôle du nombre de fragments générés). Nous proposons ensuite une approche gloutonne de sélection d'IJB. L'utilisation séparée de la fragmentation horizontale (FH) et des IJB ne permet pas d'exploiter les similarités existantes entre ces deux techniques. Nous proposons une approche de sélection conjointe de la FH et des IJB. Cette approche peut être utilisée pour le tuning de l'entrepôt. Nous avons mené plusieurs expériences pour valider nos différentes approches. Nous proposons par la suite un outil permettant d'aider l'AED dans ses tâches de conception physique et de tuning.
Mots clés : Conception physique, Tuning, Techniques d'optimisation, Fragmentation Horizontale, Index de Jointure Binaires.

Le cerveau des mammifères est composé de deux hémisphères. Bien qu'anatomiquement séparés, ceux-ci coopèrent l'un avec l'autre par l'intermédiaire de faisceaux de fibres qui constituent les commissures cérébrales. Parmi ces commissures, le corps calleux est la plus importante, tout au moins par le nombre de fibres qui la constitue (200 à 800 millions suivant les espèces). Bien que le rôle de cette commissure soit resté longtemps inconnu, il est maintenant bien établi qu'elle transporte des messages aussi divers que des messages visuels, limbiques, auditifs, somesthésiques et moteurs d'un hémisphère à l'autre. En conséquence, le corps calleux s'est révélé être impliqué dans des fonctions cognitives supérieures telles la perception sensorielle, l'apprentissage, la mémoire et la motricité. En dépit de l'établissement de ces concepts importants, la connaissance du corps calleux et de son rôle dans les fonctions cognitives supérieures restent encore extrêmement incomplètes que ce soit au cours du développement ou chez l'adulte. Or, ces questions sont essentielles puisqu'elles posent directement le problème du rôle de l'intégration interhémisphérique dans l'élaboration des fonctions cognitives dans les conditions normales; elles touchent également le problème du rôle de cette même intégration dans les processus de réorganisation et de compensation qui peuvent se développer dans les conditions pathologiques, conduisant à une restructuration des fonctions cognitives. Ce travail de thèse a été réalisé dans le contexte expérimental de C. Milleret et de ses collaborateurs qui étudient les caractéristiques anatomo-fonctionnelles et topographiques des cartes corticales calleuses localisées au niveau des aires visuelles corticales primaires 17 et 18 de chaque hémisphère chez le mammifère et qui sont associées au traitement de la région médiane verticale centrale du champ visuel. Cette région centrale du champ visuel est des plus stratégiques d'un point de vue perceptif puisqu'elle participe à la fusion des deux hémichamps visuels. En utilisant les techniques d'électrophysiologies in vivo et anatomiques (reconstructions 3D d'axones marqués à la biocytine), il a déjà été montré que ces connexions interhémisphériques sont presque exclusivement limitées à la bordure de transition entre les aires visuelle primaires A17 et A18. De plus, les neurones des aires visuels primaires qui sont activés par les axones interhémisphériques présentent des caractéristiques fonctionnelles bien précises. Certaines caractéristiques anatomo-fonctionnelles et topographiques des cartes corticales calleuses sont déjà bien identifiées mais elle se révèlent encore insuffisantes pour préciser le rôle du corps calleux dans les processus d'intégration visuelle interhémisphérique, en particulier en l'absence de données précises des caractéristiques dans les domaines temporels et spatiaux et la façon dont elles sont modifiées dans des conditions de développent visuel asymétriques. Ceci résulte aussi du faible nombre de travaux faisant appel à une approche computationnelle et la modélisation pour aborder ces questions. En particulier, les relations entre les caractéristiques morphologiques des axones calleux et les propriétés spatiales (cartes fonctionnelles) et temporelles (latences de transfert et propriétés spectrales) des populations neurales qu'elle mettent en relation sont encore très imprécises. Caractérisation quantitative des distributions des terminaisons d'axones calleux. Dans sa première partie, notre étude propose de préciser les extensions spatiales et les caractéristiques morphologiques des arborisations d'axones calleux obtenus dans les conditions de développement visuel normal (NR) et dans les conditions de déprivation monoculaire précoces (MD) afin de les différentier quantitativement. Dans cet objectif, deux groupes d'axones reconstruits en 3D sont tout d'abord décrits qualitativement par les méthodes conventionnelles d'anatomie. Cette méthode rencontre néanmoins des difficultés pour caractériser précisément les morphologies des axones, en particulier l'extension de leur terminaisons sur la surface du cortex, leur orientation et leur degré de fragmentation. Pour répondre à ces questions, deux méthodes computationnelles complémentaires et de complexité croissante ont été développées pour caractériser les distributions de terminaison axonales calleuses et mettre en évidences les différences entre les deux groupes. Celles-ci nous ont permis de montrer les plus grandes extensions spatiales ainsi que le plus grand degré de fragmentation des distributions des terminaisons des axones calleux du groupe MD. Dans un dernier chapitre, la simulation de propagation de potentiel d'action dans les structures axonales a permis de montrer que les différences morphologiques constatées dans le groupe MD, ne semblent pas se répercuter sur la dispersion temporelle du signal entre les terminaisons. Ainsi, la distribution temporelle du signal controlatéral demeure pour la grande majorité confinée dans un intervalle inférieur à 2ms, dispersion compatible avec des hypothèses de synchronisation. Développement de la technique d'imagerie optique par colorant sensibles au potentiels Avec la perspective d'explorer expérimentalement les propriétés spatio-temporelles de l'intégration visuelle interhémisphérique et afin de corroborer les résultats présenté dans la première partie de la thèse, la mise en place d'un poste expérimental d'imagerie optique au sein de notre laboratoire est présentée dans la deuxième partie. Cette méthode permet de visualiser in vivo les domaines d'activation spécifique à différents attributs au sein des cartes corticales calleuses et d'approcher certaines caractéristiques temporelles de l'activité neuronale. Réalisé en parallèle avec les travaux de modélisation des axones calleux, le montage complet du poste a montré d'abord permis de cerner les limitations du système initial. Dans un deuxième temps l'adaptation du système à la problématique interhémisphérique, réalisée au fils des mois, a montré d'importants progrès après plusieurs modifications spécifiques. La mise en place du poste expérimental a pu bénéficier de l'expertise en imagerie optique de l'équipe de recherche du Dr. S. Tanaka au RIKEN Brain Science Institute au Japon, où l'auteur a effectué plusieurs séjours au cours desquelles ont pu être initiées un certain nombres d'adaptation importantes comme le développement du protocole d'enregistrement en Voltage Sensitive Dye (VSD), permettant l'enregistrement de l'activité neurale avec un grande précision temporelle, ainsi que le développement de techniques de traitement des signaux appropriées. La mise en place du poste expérimental dans les locaux parisiens a pu être achevée fin 2006 avec l'obtention de données prometteuses pour la poursuite du programme expérimental, comme l'enregistrement à 3 ms/image de l'activation corticale bilatérale et ainsi que celle du transfert interhémisphérique. Ces résultats ouvrent les perspectives de recherche visant la combinaison des données anatomiques morphologiques avec les données d'enregistrement d'activations spatio-temporelles in vivo de l'intégration visuelle hémisphérique au sein des cortex visuels primaires.

Landscape metrics measure the composition and configuration of habitats within landscapes; often the goal is to measure fragmentation. While a variety of existing metrics characterize the connectivity and contiguity of habitat patches, most do not explicitly consider the fragmenting effects of roads in their formulations. This research develops a set of new landscape metrics that explicitly quantify how roads disconnect and break apart habitat patches. This research introduces the following four metrics to consider the fragmenting effects of transportation networks: (1) Number of Connected Patches, a measure of connectivity; (2) Euclidean Nearest Neighbor-Roads, a measure of proximity; (3) Road Density, a measure of dispersion, and (4) Distance to Roads, a measure of division. Each of these formulations explicitly considers the presence of roadways. The metrics are applicable at three spatial scales: patch, class, and landscape. Number of Connected Patches (NCP) provides a new roadway-sensitive measure of patch connectivity by computing the number of patches of identical cover type in a landscape that can be traversed on the shortest straight line distance between them without crossing a road. Euclidean Nearest Neighbor-Roads (ENNR) calculates the distance to the Euclidean nearest neighbor of a patch of the same cover type that is not separated by a roadway. Road Density (RD) leverages the ratio of total roadway network length intersecting a patch, class, or landscape versus respective total unit area. Distance to Roads (DR) provides a new measure of division by taking the shortest Euclidean distance in meters of any patch to the nearest roadway. The performance of the new metrics is evaluated using simulated landscape data with different transportation network structures and habitat patch configurations. This is accomplished by comparing output from the road-based metrics to existing metrics that quantify habitat density, isolation, dispersion, and division. The results of the study demonstrate that the new road-based landscape metrics provide an improved means of quantifying habitat fragmentation caused by transportation networks. This is especially evident as simulated transit network increases for each landscape; response of new metrics to increased road presence is linear and as expected given metric design. These metrics have successfully captured notable patch, class, and landscape level characteristics and their associated responses which are not available with treatment by conventional measures of landscape fragmentation.

L’occupation du sol en zone forestière de Yangambi dans la Cuvette centrale congolaise (RDC) change rapidement et la fragmentation forestière liée à l’agriculture itinérante sur brûlis est devenue l’un des processus dominant la dynamique paysagère. La présente étude s’est fixée comme objectif de suivre une approche microclimatique en transects pour déterminer la zone de lisière entre les jachères herbeuses et les forêts denses, et ce, afin de mieux comprendre les réponses des propriétés physico-chimiques du sol aux changements d’occupation du sol et à la fragmentation forestière. Deux zones les plus appréciées par les paysans pour leurs exploitations agricoles ont été choisies en fonction des unités pédologiques existantes :la série Yangambi et la série Yakonde. Des échantillons non perturbés du sol de 0-10, 10-20 cm, 20-30 cm et perturbés de 0-20 cm ont été prélevés dans les différentes occupations de sols après la détermination de la zone de lisière. Notre démarche a consisté à comparer les propriétés de sols identiques au plan de leur pédogenèse, sous jachère herbeuse, sous lisière et sous couvert forestier, de façon à quantifier l’effet de lisière sur les propriétés des sols, pour mieux connaître les conséquences édaphiques de la fragmentation des forêts par l’agriculture itinérante sur brûlis.

Les résultats obtenus ont montré que la zone de lisière entre les jachères et les forêts denses a une largeur de 70 m pour la série Yangambi et 68 m pour la série Yakonde. Les variations microclimatiques de la lisière en terme de température de l’air, sont intermédiaires (moyenne, minima et maxima) entre celles des jachères herbeuses et des forêts denses. La fragmentation des forêts par l’agriculture itinérante sur brûlis modifie profondément les propriétés physico-chimiques de sols dans les couches superficielles. Un des effets de changements d’occupation du sol et de la fragmentation est la présence d’horizons superficiels à texture sableuse au niveau des jachères herbeuses et des lisières forestières. La densité apparente et la conductivité hydraulique ont subit une importante dégradation sous les jachères herbeuses. A l’inverse, la lisière forestière assure une bonne structure conservatrice du sol (faible densité apparente et bonne conductivité hydraulique). Le sol des forêts denses présente des bonnes propriétés physiques et de ce fait, est pris comme référence à partir duquel les effets de dégradation physique du sol peuvent être appréciés.

Le potentiel chimique du sol (pH, phosphore assimilable, le taux de saturation en bases et la CECE) est meilleur au niveau des jachères herbeuses et des lisières forestières par rapport aux forêts denses suite à la pratique du brûlis qui permet de restituer au sol une fraction de la minéralomasse forestière par les cendres. Les teneurs en carbone et azote totaux du sol ont été significativement plus élevées sous les lisières forestières que sous les jachères herbeuses et les forêts denses. Les résultats de l’indice de Kamprath ont montré que, les lisières, en plus de contribuer à l’accroissement de carbone organique du sol, tendent à diminuer la toxicité aluminique de sols étudiés. A l’inverse, l’étude a mis en évidence une toxicité aluminique plus élevée sous la jachère herbeuse de la série Yangambi que sous la lisière. En parallèle, nous avons observé une baisse des teneurs en fer sous toutes les jachères et les lisières forestières.

Les pratiques de jachères cultivées et d’agroforesterie s’avèrent incontournables pour enrichir ces sols en matière organique, limiter l’érosion liée au brûlis afin de freiner le lessivage des nutriments, éviter le compactage du sol et assurer le maintien à long terme d’une bonne structure conservatrice du sol.

In the forest zone of Yangambi, located in the Central Congo Basin (DRC), land use is changing rapidly and forest fragmentation due to slash and burn agriculture has become one of the dominant processes of landscape dynamics. This study's main goal is to apply a microclimatic approach in transects to determine the edge area between the fallow grasslands and dense forests, and, in order to better understand the responses of the soil physico-chemical properties to changes in land use and forest fragmentation. Two most popular areas used by farmers have been selected on the basis of the existing soil units: the Yangambi and Yakonde series. Undisturbed soil samples at depths of 0-10 cm, 10-20 cm, 20-30 cm and the disturbed at 0-20 cm were collected from different the land use types after detecting the edge area. Our approach was to compare the properties of identical soils based on their genesis, under grass fallow, edge and forest cover, so as to quantify the effect of edge on the soil properties, to better understand the edaphic consequences of the forest fragmentation by slash and burn shifting cultivation.

The results showed that the edge area between fallow and dense forests has a width of 70 m for the Yangambi series and 68 m for the Yakonde series. Microclimatic variations of the edge in terms of air temperature are intermediate (average, minimum and maximum) between grass fallows and dense forests. The fragmentation of forests by slash and burn shifting cultivation profoundly modifies the physico-chemical properties of soils in the surface layers. One of the effects of changes in land use and fragmentation was the presence of surface layers with more sandy texture in the fallow grassland and forest edges. Bulk density and hydraulic conductivity undergo an important degradation under grass fallows. In contrast, the forest edge ensures a maintenance of the soil structure (low bulk density and good hydraulic conductivity). Dense forest soil has thus good physical properties and therefore is taken as the reference from which the effects of soil physical degradation can be appreciated.

The chemical potential of the soil (based on pH, available phosphorus, base saturation and CECE) is better in the grass fallows and forest edges compared to dense forests due to the practice of slash and burn which allows restoration by adding nutrients to the soil through the ashes. The carbon and total nitrogen in the soil were significantly higher under forest edges than in fallow grasslands and dense forests. The results of the-Kamprath index shows the edges, in addition to contributing to an increase in soil organic carbon, tend to decrease the aluminium toxicity of studied soils. By contrast, the study revealed a higher aluminium toxicity under fallow grassland on the Yangambi series that under the edge and the forest. In parallel, we observed a decrease in iron contents in all fallow lands and forest edges.

The practices of cultivated fallows and agroforestry are proving unavoidable for enriching these soils in organic material, to reduce erosion related to slash and burn in order to curb the leaching of nutrients, to avoid soil compaction and to maintain a long-term well developed soil structure.

Doctorat en Sciences agronomiques et ingénierie biologique
info:eu-repo/semantics/nonPublished

I am interested in two spaces obverse to each other: open and closed. An open space develops organically based on how people inhabit it. Interacting with an open space is a dynamic, sporadic, multisensory, immersive, and subjective experience. In such spaces, we are confronted with an alternative aesthetic, one that is in conflict with the seamlessness of a closed space. A closed space is anchored on definite variables like structure, use and boundaries. While interaction between people and space is important, the space is tightly controlled and interaction is designed. Through this thesis project, I present a method that metaphorically transforms the experience of a walk through a closed space into an open-ended and immersive experience. When space develops as a response to our actions, it affords intimacy and a sense of belonging. It facilitates deeper expressiveness through engagement. By applying a method that uses fragmentation, recurrence and motion, I am metaphorically transforming an urban closed space to open. Through this transformation I am creating a fresh person-space dialogue that temporarily destabilizes perception and encourages physical sensation which allows for an intimate experience of the space. An immersive interaction with an open space transgresses the urban sterility of a closed space and is capable of creating a diversity of distinct experiences.

The decrease of semi-natural grasslands in Europe during the last decade has made several previously common species rare or declining in numbers. One of these species is the endangered field gentian Gentianella campestris, which has been proposed as an important indicator species for semi-natural grasslands. Previous studies have highlighted the importance of consistent management and shown how local conditions affect the species. Less is known about how the population is affected by isolation and changes in the surrounding landscape, both of which are potential consequences of habitat loss.This study utilized long term citizen science data on the population changes to explore if local and regional factors, such as connectivity could explain the rapid decline and local extinctions that the field gentian population in Östergötland, Sweden, has experienced since the beginning of the 1990’s. Generalized linear models showed that the declining field gentian population can partly be explained by changes in the surrounding landscape which has led to decreased connectivity of semi-natural grasslands. The study also indicate that there is a need for future management plans to consider the surrounding landscape on a distance of 1-3 km from field gentian localities as this scale seems to be the most important.

Les étoiles se forment dans les nuages moléculaires, lorsque ceux-ci s'effondrent et se fragmentent pour former ce que l'on appelle des coeurs denses protostellaires. Ces coeurs denses sont ensuite susceptibles de se contracter sous l'effet de leur propre masse, et de former de jeunes proto-étoiles, qui évoluent en accrétant leur matériel circumstellaire jusqu'à atteindre la séquence principale. L'objectif principal de cette thèse a été d'étudier la formation et la fragmentation des coeurs denses protostellaires. Pour cela, deux études principales, présentées dans ce manuscrit, ont été menées. La première a consisté à étudier la formation des coeurs protostellaires, en quantifiant l'influence des flots protostellaires sur la formation stellaire en amas. Grâce à une étude des flots protostellaires générés par les objets stellaires jeunes en formation dans le proto-amas NGC 2264-C, nous montrons que les flots protostellaires peuvent jouer un rôle important en tant que progéniteurs de turbulence dans les régions de formation stellaire en amas, bien qu'ils semblent incapables de modifier significativement les processus d'effondrement global à l'échelle de la plupart des clumps. Deuxièmement, nous nous sommes intéressés à la question de la formation des systèmes multiples par fragmentation des cœurs protostellaires, en sondant la multiplicité des proto-étoiles les plus jeunes. Notre étude suggère que le taux de multiplicité aux petites échelles des proto-étoiles augmente au cours de leur évolution, et favorise des scénarios dynamiques de formation des systèmes multiples. Enfin, nos résultats favorisent les scénarios magnétiques pour les stades précoces de la formation des proto-étoiles.

L'évolution rapide et les bouleversements successifs sont des traits caractéristiques du transport international aérien. Près de soixante-dix ans après la signature de la Convention de Chicago relative à l'aviation civile internationale, un constat s'impose : l'importance économique du transport aérien a considérablement augmenté. Qu'il s'agisse de transporter des marchandises, au soutien du commerce international, ou des individus, de plus en plus nombreux à avoir accès à ce mode de transport, une véritable prise de conscience de la part des Etats a révolutionné les paradigmes traditionnels du droit aérien ; ce dernier, initialement tourné vers les aspects de sécurité et sûreté des transports, ne peux plus délaisser la dimension économique du secteur. Parallèlement, la société internationale a connu un phénomène de complexification croissante. Cette évolution ne résulte pas seulement de l'apparition progressive, dans la période d'après guerre froide, d'un monde multipolaire, mais également d'un développement matériel du droit international aujourd'hui divisé en de multiples régimes juridiques indépendants aux légitimités politiques et juridiques égales. Ainsi a-t-on assisté au développement d'un droit international de l'environnement, d'un droit international du commerce, ou encore d'un droit international du développement. La présente étude a pour objet l'étude de l'évolution du droit international du transport aérien, historiquement associé à l'Organisation de l'Aviation Civile Internationale (OACI) et « ses » diverses conventions internationales, dans le contexte de la fragmentation du droit international. A travers cette démarche, l'évolution factuelle et juridique du droit associé au système de l'OACI sera mis en perspective dans ses rapprochement au système traditionnellement associé à la libéralisation du commerce international, celui de l'Organisation Mondiale du Commerce (OMC). Sera notamment souligné la « crise identitaire » actuellement traversée par le droit du transport aérien et les diverses pistes qui pourraient être explorées par les Etats pour favoriser le développement harmonieux du transport international aérien.
Fast evolution and successive dislocations are well known attributes of international air transportation. Nearly seventy years after the Chicago Convention has been signed, one must acknowledge the economic importance of international transportation has grown considerably. Focusing both on transportation of goods, supporting the development of international trade, and transportation of individuals, whose access to air transportation has constantly grown, States and their governments began to modernize, and thereby revolutionize air law's traditional paradigms; air law, initially focusing exclusively on safety and security aspects of transportation, must now integrate the economical dimensions of air transportation. At the same time, international society has become more and more complex in two different ways: firstly, in the Post-Cold War Area, a multi-polarized world began to emerge. Secondly, material developments of international law have resulted in the apparition of numerous independent legal systems of the same value such as environmental international law, international trade law or international development law. The main purpose of the following thesis is to study the recent evolutions of international air transportation law, historically based on the creation and development of the International Civil Aviation Organization (ICAO) and associated international conventions, within the framework of the fragmentation of international law. Through this study, both the legal and factual evolutions of IACO Law will be addressed in the perspective of its joined application with the World trade Organization (WTO) law. Particular attention will be given to the question of an "identity crisis" the air transportation law is said to suffer from, and to the different ways of thoughts that could be followed to support a healthy economic development on international air transportation.

Modern application are becoming more complex and demanding in terms of resource utilization. LTE network is part of those applications. Efficient memory utilization poses a great challenge to developers. The dynamic memory allocations and de allocations over the program execution time leads to a problem called memory fragmentation, which can eventually lead the system out of memory. Currently there are many allocators that are specifically designed for dynamic memory management. This thesis contains the study and analysis of three different allocators, ptmalloc2, tcmalloc and tlsf. The goal of the thesis is the evaluation of their performance in terms of memory fragmentation and cpu execution time. The allocators are tested against a real program tracing file, which contains a sequence of allocations and deallocations captured from an executing process.