Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-06-28T14:29:11Z No. of bitstreams: 1 damiaodesousavieirajunior.pdf: 10265456 bytes, checksum: 8b1ceaeb4c4be0e91a46c2d30add7349 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-08-07T21:17:55Z (GMT) No. of bitstreams: 1 damiaodesousavieirajunior.pdf: 10265456 bytes, checksum: 8b1ceaeb4c4be0e91a46c2d30add7349 (MD5) / Made available in DSpace on 2017-08-07T21:17:55Z (GMT). No. of bitstreams: 1 damiaodesousavieirajunior.pdf: 10265456 bytes, checksum: 8b1ceaeb4c4be0e91a46c2d30add7349 (MD5) Previous issue date: 2016-02-03 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O contínuo desenvolvimento das técnicas de fabricação de estruturas em escala nanométrica, com considerável precisão e reprodutibilidade, tem permitido e estimulado a investigação científica em torno das propriedades básicas e novas aplicações tecnológicas desses sistemas. Especialmente a partir dos anos 90, é crescente o interesse da comunidade científica no comportamento de sistemas magnéticos nano-estruturados. Nestes, a quebra da simetria espacial devido às pequenas dimensões faz com que exibam comportamentos completamente distintos dos observados em amostras macroscópicas. A anisotropia de forma resultante das interações clássicas entre os dipolos magnéticos permite a formação de estruturas magnéticas exóticas em nanomagnetos como vórtices, skyrmions, paredes de domínio individuais e, até mesmo, excitações topológicas similares a monopolos magnéticos. A compreensão e controle do comportamento magnético estático e dinâmico dessas estruturas é fundamental para o desenvolvimento de novos dispositivos tecnológicos baseados em spintrônica. Neste trabalho foram estudadas nanopartículas planares, alongadas na forma elíptica, de material ferromagnético macio, especificamente o Permalloy-79. Tais nanopartículas tem atraído atenção devido ao seu potencial de aplicação prática no desenvolvimento de novos sensores, dispositivos de lógica, mídias de armazenamento de dados de alta densidade e dispositivos MRAM (Magnetic Random Access Memory). Pelo viés do interesse científico básico, tais nano-ilhas ferromagnéticas são a unidade fundamental em arranjos magnéticos bidimensionais geometricamente frustrados, como sistemas de gelo de spin artificiais. Nestes sistemas o arranjo geométrico das ilhas quebra a degenerescência do estado fundamental da rede, caracterizando um estado de frustração geométrica que permite excitações de comportamento análogo ao de monopólos magnéticos. Sob tais aspectos, é essencial caracterizar as configurações magnéticas no estado fundamental e os processos de reversão da magnetização em nanopartículas individuais. A forma elíptica planar gera uma forte anisotropia magnética, definindo duas configurações fundamentais para a magnetização do estado fundamental das nanopartículas: o estado de vórtice ou o estado alinhado ao longo do maior eixo — estado tipo C. A partir de uma razão de aspecto limite, a magnetização do estado fundamental é confinada no plano e ao longo do eixo maior de cada nano ilha, definindo um nanomagneto monodomínio com dois estados degenerados de magnetização, útil às aplicações previamente descritas. Partindo desse intuito estudamos inicialmente, através de simulação por dinâmica de spin, a competição entre os estados de vórtice e os estados alinhados tipo C como uma função da forma de cada nano-ilha elíptica, construindo um diagrama de fases de estados vórtice - tipo C. Cada nanopartícula magnética é modelada por momentos magnéticos que interagem via interação de troca entre primeiros vizinhos e por interação dipolar clássica de longo alcance. Nossos resultados mostram que é possível fabricar nano-ilhas alongadas com estado fundamental alinhado tipo C em razões de aspecto menores que dois. Este é um resultado interessante do ponto de vista tecnológico, pois permite usar ilhas menores que as atuais em pesquisas com gelos de spin e MRAM. Geralmente, os arranjos experimentais são feitos com nanopartículas de razão de aspecto próximas a três para garantir o estado fundamental alinhado da magnetização. Acrescentando ao modelo um termo de interação Zeeman com um campo magnético externo, estudamos o comportamento da reversão da magnetização nas nanopartículas. Consideramos espessuras diferentes e duas razões de aspecto distintas: uma do tamanho experimental usual e outra menor proposta a partir de nossos resultados. Aplicando campo magnético senoidal em diferentes frequências e em direções distintas no plano das nanoilhas, observou-se a dependência dos processos de reversão em função da espessura das partículas e com a direção e frequência do campo aplicado. Os resultados permitem traçar linhas gerais acerca do comportamento da reversão da magnetização nas nanopartículas individuais sob campo magnético externo. Evidentemente para o desenvolvimento das possíveis aplicações tecnológicas, inclusive o controle de excitações como monopólos magnéticos em gelos de spin, é crucial entender os processos ultra rápidos de reversão da magnetização, o que envolve a aplicação de campo externo de alta frequência em direções cuidadosamente definidas. Com esse objetivo, também estudamos a reversão da magnetização nas nano-ilhas por pulsos curtos de campo magnético (da ordem de nanosegundos) aplicados em diferentes direções. Observamos uma forte dependência da coerência da reversão da magnetização com a direção do campo aplicado e uma significante diferença na dependência angular da coercividade em relação ao observado em trabalhos prévios para campos aplicados na condição quase-estática. Finalmente, baseado em nossos resultados, propomos um método para o controle da reversão coerente da magnetização de nanopartículas individuais em matrizes quadradas de gelos de spin artificiais. Acreditamos que nossos resultados poderão ser úteis no desenvolvimento ulterior de arranjos magnéticos artificiais geometricamente frustrados e no controle das excitações topológicas destes sistemas. / The continuous development of structures fabrication techniques at the nanometer scale with considerable precision and reproducibility has allowed and encouraged scientific research around the basic properties and new technological applications of these systems. Especially from the 90's, there is growing interest of the scientific community in the behavior of nanostructured magnetic systems. In these, the breaking of spatial symmetry due to small dimensionality causes quite different behaviors from those observed in the bulk. The resulting shape anisotropy of the classical interaction between magnetic dipoles allows the formation of exotic magnetic structures in nanomagnets as vortices, skyrmions, single domain walls and even topological excitations similar to magnetic monopoles. The understanding and control of static and dynamic magnetic behavior of these structures is essential for the development of new technological devices based on spintronics. In this work we studied planar elongated nanoparticles in the elliptical shape of soft ferromagnetic material, specifically the Permalloy-79. Such nanoparticles have attracted attention because of their potential to practical application in the development of new sensors, logic devices, high density data storage media and MRAM (Magnetic Random Access Memory) devices. By the bias of basic scientific interest, such ferromagnetic nano-islands are the fundamental unit in two-dimensional magnetic arrangements geometrically frustrated as artificial spin ice systems. In these systems, the geometric arrangement of islands break the degeneracy of the network ground state featuring a state of geometrical frustration that allows excitations with analogous behavior of magnetic monopoles. Under these aspects, it is essential to characterize the magnetic configurations in the ground state and the magnetization reversal processes in individual nanoparticles. The elliptical planar shape generates a strong magnetic anisotropy which defines two basic configurations for the magnetization of the ground state of the nanoparticles: the vortex state or the aligned state along the major axis - type C state. As from an aspect ratio limit value, the magnetization of the ground state is confined in the plane and along the major axis of each nano-island defining mono-domain nanomagnet with two degenerate states of magnetization, useful for the applications previously described. Starting from this purpose we study initially, through simulation by spin dynamics, the competition between the vortex states and aligned type C states as a function of the shape of each elliptical nano-island to build a states diagram. Each magnetic nanoparticle is modeled by magnetic moments that interact by exchange interaction between nearest neighbors and by the classical long-range dipolar interaction. Our theoretical results indicate the possibility to manufacture elongated nano-islands with ground state like aligned C state for aspect ratios less than two. This is an interesting result from the technological point of view because it will be possible to use smaller islands in researches on spin ice and MRAM. Generally, the experimental arrangements are made with nanoparticles of aspect ratio close to three to ensure aligned magnetization in the ground state. Adding to the model a Zeeman interaction term between the magnetic moments and an external magnetic field we study the behavior of the magnetization reversal in nanoparticles. We consider different thickness and two different aspect ratios: one in the usual experimental size and a smaller proposed from our results. Applying sinusoidal magnetic field at different frequencies along the anisotropy axis in directions of ten and forty-five degrees from this, we observed the dependence of the reversal processes on the thickness of the particles and with the direction and frequency of the applied field. The results allow to establish general guidelines about the magnetization reversal behavior of the individual nanoparticles under external magnetic field. Evidently, for the development of possible technological applications, including the control of excitation like magnetic monopoles in spin ice, it is crucial to understand the ultrafast magnetization reversal processes which involves the application of high frequency magnetic fields in carefully defined directions. With this aim, we also studied the magnetization reversal of the nano-islands by short pulses of magnetic field (of the nanosecond order) applied in different directions. We observed a strong dependence on the coherence of the magnetization reversal with the direction of the applied field and a significant difference in the angular dependence of the coercivity compared to those seen in previous studies with applied magnetic fields in quasistatic conditions. Finally, based on our results we propose a method for the control of the coherent magnetization reversal of individual nanoparticles in square artificial spin ice arrays. We believe that our results may be useful in further developments of geometrically frustrated magnetic artificial arrangements and in the control of the topological excitations of these systems.

La tentation est grande de proclamer qu’aujourd’hui toute imprévisibilité a disparu. Dès lors qu’un fait s’est produit, il semble rétrospectivement acquis qu’il était prévisible avant même sa réalisation. Puisque l’on doit s’attendre à tout, rien ne peut être considéré comme imprévisible ; ni une crise économique, ni une catastrophe naturelle, ni un simple accident, dont on sait qu’ils peuvent survenir à n’importe quel moment, frapper n’importe où et n’importe qui. L’imprévisibilité, privée de consistance et d’effets, se voit alors inexorablement écartée du domaine du droit.Pourtant, l’imprévisibilité demeure une réalité, dès lors que l’on est incapable de prévoir le moment, le lieu, l’intensité ou la victime du fait. Admettre l’existence de l’imprévisibilité sans renoncer à l’encadrer, voilà le défi qui est lancé au droit. Les moyens d’y répondre sont nombreux mais épars, et leur application souffre souvent d’une mauvaise identification de la notion. L’ambition de cette étude est de démontrer que l’imprévisibilité du fait innerve l’ensemble du droit privé contemporain, et de dessiner les contours de l’attitude de ce dernier à son égard. Une réception ordonnée et délimitée d’une imprévisibilité irréductible n’est à ce titre pas incompatible avec une attitude plus active du droit pour canaliser cette imprévisibilité. Identifier ses effets de droit, construire une définition, démontrer les ressorts et les possibilités de l’anticiper ou de la maintenir, tels sont les éléments indispensables à apporter à la réflexion juridique pour que le droit puisse faire face le plus sereinement possible à l’imprévisibilité d’un fait. / Nowadays, one could be tempted to state that the concept of unpredictability has disappeared. Indeed, if some event actually occurs, it is likely to be deemed predictable retrospectively, even before its taking place. As any event can occur, no event can be deemed unpredictable any longer : neither an economic crisis, nor natural disaster, nor the most banal accident. It is common knowledge that such events may occur at any time, strike anybody, anywhere. In this way, unpredictability is deprived of its legal purpose and effects and discarded by law. However, unpredictability remains a reality, when one is unable to foresee the moment, the place, the intensity or the victim caused by the event. The challenge laid down by law shall consist in recognizing the existence of unpredictability in order for law to be able to frame this concept. There are many ways to reach this goal, and the solutions and their implementation remain dispersed owing to the difficulty to clearly identifying the concept of unpredictability. The purpose of this study is to demonstrate that the notion of unpredictability invigorates the whole scope of contemporary private law, and to show how this concept shall be apprehended by law. A defined and specific implementation of the irreductible aspects of the concept of unpredictability by law will not be incompatible with a more active approach, in order for unpredictability to be captured by law. Identifying legal effects, creating a definition, demonstrating the means and the abilities to anticipate unpredictability or to maintain it, will remain essential steps in the legal constructing, so that law shall be able to face unpredictability serenely.

No description available.

Uměle vytvořené systémy spinového ledu jsou vhodným nástrojem pro zkoumání neobvyklých jevů, které se v přírodě dají jen těžko pozorovat. Speciálním případem umělého spinového ledu je kagome mřížka, která umožňuje zkoumat kolektivní chování spinů v látce. Tento systém má řadu předpovězených exotických magnetických fází, které zatím nebyly změřeny a prozkoumány v reálném prostoru. V rámci této práce se zabýváme úpravou kagome mřížky tak, aby mohla být využita ke zkoumání exotických stavů v reálném prostoru. Experimenty provedené na naší upravené mřížce ukazují, že jsme schopni detekovat nízko i vysoko energiové stavy, a tedy, že námi navržená úprava kagome mřížky je vhodná pro zkoumání exotických stavů v reálném prostoru.

Inre motivation som konceptualiseras inom Self Determination Theory (SDT) (Deci & Ryan, 2000) har en viktig roll i att främja fortsatt idrottande och välmående. Till vilken grad en individ upplever inre motivation kan ses utifrån faktorerna behovstillfredsställelse och behovsfrustration. Motivationen påverkas även av omgivningen genom så kallat behovsstöd och behovshindrande. Denna studie syftade till att undersöka om det fanns något samband mellan svenska badmintonspelares upplevelse av behovstillfredsställelse/-frustration och behovsstöd/-hindrande och deras intention att fortsätta med badminton i framtiden. 133 aktiva svenska badmintonspelare, i åldern 15-66 år och äldre deltog i studien. Intentionen att fortsätta spela badminton uppvisade ett statistiskt signifikant positivt samband med variablerna behovsstöd och behovstillfredsställelse. Inget samband hittades mellan Intentionen att fortsätta spela badminton och variablerna behovshindrande och behovsfrustration. Intentionen att fortsätta spela badminton var även högre ju äldre spelaren var, ju fler år spelaren spelat badminton och ju fler år med nuvarande huvudtränare de haft.  Behovsstöd och behovstillfredsställelse förefaller således vara områden att fokusera på inom idrottsföreningar med syfte att bidra till ett långsiktigt idrottande, även inom andra idrotter än badminton. / Studies have shown the importance of intrinsic motivation and Self Determination Theory (SDT) (Deci & Ryan, 2000) when it comes to promoting sport participation and well-being. The amount of intrinsic motivation experienced by an individual can be estimated using the factors Need Satisfaction and Need Frustration and also be influenced by the surrounding people through Need Support and Need Thwarting. This study aimed to investigate whether a correlation between the experience of Need Satisfaction/-Frustration and Need Support/-Thwarting in Swedish badminton players and their intention to continue with badminton in the future existed. 133 active Swedish badminton players participated in the study, age 15 to 66 and older. The intention to continue playing badminton indicated a statistically significant positive correlation with the variables Need Support and Need Satisfaction. No correlation was found between the intention to continue playing badminton and the variables Need Thwarting and Need Frustration. The higher the age, more years as an active badminton player and more years with their current coach, the higher was also the intention to continue with badminton in the future. Need Support and Need Satisfaction can therefore be important areas of interest within sport clubs to promote long-term sport participation, in badminton as well as other sports.

Die Arbeit befasst sich mit der Elektronenspinresonanz (ESR) stark korrelierter Elektronensysteme mit ferromagnetischen Wechselwirkungen. Es wurden dafür Messungen an den Kondogitter-Systemen CeRuPO und CeOsPO, der Dotierungsreihe CeFeAs1-xPxO, den niederdimensionalen frustrierten Quadratgittern AA’VO(PO4)2 sowie in dem schwach ferromagnetischen Metall Nb1-yFe2+y durchgeführt. Alle Verbindungen zeigen entweder eine ferromagnetische Ordnung oder befinden sich in der Nähe einer ferromagnetischen Instabilität, die die Eigenschaften des stark korrelierten Systems beeinflusst.:Abkürzungsverzeichnis xi Einleitung 1 1 Theoretische Modelle 5 1.1 Auswirkungen des Kristallfeldes 1.2 Phasenübergänge, Landau-Ginzburg Theorie und Quantenphasenübergänge 1.3 Physik Niederdimensionaler Spin-Systeme 1.3.1 Das zweidimensionale XY-Modell 1.3.2 Das J1-J2-Modell auf dem Quadratgitter 1.4 4f-Magnetismus, Kondoeffekt und Kondogitter 1.4.1 Vom freien Elektronengas zur Landau-Fermi-Flüssigkeit 1.4.2 Kondo-Effekt, RKKY-Wechselwirkung und Schwere Fermionen Systeme 1.4.3 Cer: 4f-Magnetismus 1.5 Schwach magnetische Metalle 1.5.1 Pauli-Suszeptibilität und spontan aufgespaltene Bänder 1.5.2 Spinfluktuationen in itineranten Magneten und marginale Fermiflüssigkeit 1.6 Dichtefunktionaltheorie 2 Grundlagen der Elektronenspinresonanz 31 2.1 Prinzip der magnetischen Resonanz und ESR Parameter 2.1.1 Linienform 2.1.2 Intensität 2.1.3 g-Faktor 2.1.4 Linienbreite und Spin-Relaxation 2.2 Experimenteller Aufbau 2.3 ESR in niederdimensionalen Systemen 2.4 ESR an Metallen und Kondogitter Systemen 2.4.1 Auswirkungen der Wechselwirkungen zwischen lokalen Momenten und Leitungselektronen auf die ESR 2.4.2 ESR in Kondogittersystemen 2.5 Leitungselektronenspinresonanz 2.5.1 Linienform in der LESR 2.5.2 Elliot-Yafet Theorie und ihre Verallgemeinerung 2.6 ESR an magnetischen Phasenübergängen 3 ESR in CeTPO (T=Ru, Os) und CeFeAs1-xPxO 59 3.1 Die Eigenschaften von CeTPO (T=Ru, Os) & CeFeAs1-xPxO 3.1.1 Das ferromagnetische Kondogitter CeRuPO 3.1.2 Das antiferromagnetische Kondogitter CeOsPO 3.1.3 Die Dotierungsreihe CeFeAs1-xPxO 3.2 CeRuPO und CeOsPO: Die Bedeutung FM Fluktuationen für die Beobachtbarkeit der ESR in Kondo-Gitter Systemen 3.3 ESR an CeRuPO Einkristallen 3.3.1 Anisotropie und Temperaturverhalten des g-Faktors 3.3.2 Anisotropie und Temperaturverhalten der Linienbreite 3.4 Entwicklung der ESR in der Dotierungsreihe CeFeAs1-xPxO 3.4.1 CeFeAs0.7P0.3O - Supraleitung und Ferromagnetismus 3.5 Zusammenfassung ESR in CeTPO und CeFeAs1-xPxO 4 ESR in den frustrierten Quadratgittern AA’VO(PO4)2 97 4.1 Struktur und magnetische Eigenschaften AA’VO(PO4)2 4.2 ESR an polykristallinen SrZnVO(PO4)2 & BaCdVO(PO4)2 4.2.1 SrZnVO(PO4)2 4.2.2 BaCdVO(PO4)2 4.3 ESR an Pb2VO(PO4)2-Einkristallen 4.3.1 Anisotropie der Resonanz 4.3.2 Temperaturabhängigkeit 4.4 Zusammenfassung der ESR in den frustrierten Quadratgittern 7 4.4.1 Analyse der Linienbreitendivergenz am Phasenübergang 5 Leitungselektronenspinresonanz in Nb1-yFe2+y 125 5.1 Das magnetische Phasendigramm von Nb1-yFe2+y 5.2 LESR in polykristallinen Nb1-yFe2+y 5.2.1 Proben mit ferromagnetischer Ordnung 5.2.2 Proben mit SDW-Ordnung 5.2.3 Zusammenfassung polykristalline Proben 5.3 Bandstruktur und verallgemeinerte Elliot-Yafet-Theorie in NbFe2 5.4 LESR in einkristallinen Proben von Nb1-yFe2+y 5.4.1 Fe-reicher Einkristall: y=0.016 5.4.2 Stöchiometrischer Einkristall: NbFe2 5.4.3 Nb-reicher Einkristall: y=-0.008 5.5 Zusammenfassung LESR in Nb1-yFe2+y 6 Zusammenfassung und Ausblick Anhang A.1 Das zweite Moment der Dipol-Dipol-Wechselwirkung A.2 Untersuchte CeFeAs1-xPxO-Proben Literaturverzeichnis

No description available.

This study was undertaken to determine the extent of aggressive behaviour exhibited by secondary school learners. Many factors were considered when investigating the problem of aggressive behaviour. The problem was traced from the theorists' perspectives and factors related to the family, school and community. An extensive literature review showed that the above factors contribute to aggressive behaviour among adolescents. In order to support or reject the findings of the literature study, quantitative (questionnaire) research and qualitative research (interviews) were conducted. The results of the quantitative research concerning learners' aggressive behaviour in secondary schools were analysed and interpreted while at the same time a deeper understanding of aggressive behaviour was revealed through qualitative research. The results of the empirical research indicated that the more negative the family climate, school climate, community climate or influence of friends are, or the more negative the emotional self-concept of the adolescent is, the more aggressive the adolescent is, and vice versa. Based on these findings recommendations for the implementation of prevention programmes were made. / Educational Studies / D. Ed. (Socio-Education)

Text in Afrikaans / Executions were discontinued during November 1989. In February 1990 the State President announced a moratorium on executions. Since 27 July 1990 the Criminal Law Amendment Act, 1990 effected important changes to the substantive law and procedure regarding the death sentence. The "new" death sentence dispensation was applied by the courts and the moratorium would be lifted as soon as the new dispensation became effective. That never materialised. The death sentence issue was dealt with in a game of political compromise. Criminal law and the esteem of the Government suffered as a result. Judicial frustration and uncertainty developed regarding application of the death sentence. The opportunity was seized by the abolitionists to attain their ideal. The Constitutional Court declared the death sentence unconstitutional. Presently a final Constitution is being drafted which will probably finally do away with the death sentence. An effective process of denigration of the death sentence thus resulted from the moratorium on executions. / Teregstellings is gedurende November 1989 gestaak. Op 2 Februarie 1990 het die Staatspresident 'n moratorium op teregstellings afgekondig. Vanaf 27 Julie 1990 het die Strafregwysigingswet, 1990, belangrike verstellings aan die materiele en prosessuele reg met betrekking tot die doodvonnis gemaak. Die "nuwe" doodvonnisbedeling is deur die howe toegepas. Die moratorium sou opgehef word sodra die "nuwe bedeling" op dreef was. Dit het nie gebeur nie. 'n Spel van kornprornie-politiek random die doodvonniskwessie het horn afgespeel. Die strafregpleging en die Regering se aansien het daaronder gely. Regterlike frustrasie het posgevat en regsonsekerheid oar die toepassing van die doodvonnis het ontstaan. Die geleentheid is deur die afskaffers aangegryp om hul ideaal te verwesenlik. Die Konstitusionele Hof het die doodvonnis ongrondwetlik verklaar. Tans word 'n finale Grondwet geskryf wat waarskynlik die doodvonnis gaan afskaf. 'n Effektiewe proses van aftakeling van die doodvonnis het dus sedert die moratorium op teregstellings plaasgevind. / Criminal & Procedural Law / LL. M.

This thesis attempts to critically and comparatively analyse the doctrine of exemption/frustration /force majeure under the United Nations Convention on the Contract for International Sale of Goods (CISG) the UNIDRIOT Principles of International Commercial Contracts (UNIDROIT) and the English Law. The doctrine of exemption/frustration/force majeure is very important in the area of contract and commercial law, it is a doctrine deeply rooted in fairness and allows a party to be excused from performing an obligation in a contract if at the conclusion of the contract an inhibition beyond the foreseeable control of the party happens to render the performance of the contract impossible. However, it is not easy to effectively streamline this doctrine and properly determine its applications. It has been observed in this thesis that, the doctrines of exemption/frustration /force majeure are not exactly the same; this thesis explores in details severally and jointly the various differences and similarities in the interpretations and applications of these impossibility doctrines. For instance, the open and flexible use of words in the definition of this doctrine under the CISG and the UNIDROIT Principles left much to be desired. Thus, it is one of the succinct arguments of this thesis that couching international law in loose words will work against the uniformity of application of this law, due to the different interpretations national law courts will be subjecting it to. This among other issues retarded the growth and development of the doctrine of exemption and force majeure. Furthermore, English law stance on the doctrine of frustration which can be gleaned from both the Sale of Goods Act of 1979 and the Common law are far from being adequate and need to be updated. This thesis therefore incisively laid bare the applications, interpretations and way forward for the doctrine of exemption/frustration/force majeure under the legal instruments of focus of this work. The thesis also comparatively compares the relationship between the doctrine of frustration/force majeure/exemption and other related doctrines like mistake, termination, avoidance, risk, and hardship. The thesis is concluded with a Draft Model Frustration Clause (DMFC) which is an attempt to rise above the status quo doctrine of frustration in the extant laws and develop a frustration clause that will be able to provide answers to the many flaws that trail these laws.