Twenty years after overcoming Apartheid, South Africa still suffers from poverty and inequality. Recent data (Income and Expenditure Survey 2011) indicates that one third of the population lives on less than USD 0.70 per day while the upper tercile has USD 28 available. The country also faces other complex challenges, including high levels of unemployment, a resource-biased economy and low levels of education, and structural reforms are much needed to put the economy on a path of sustained growth. However, structural reforms require a broad consent within society, and inequality, clearly, is a major hindrance to this. By choosing how to collect revenue and how to spend it, South Africa's government has two instruments at their disposal in order to alleviate inequality and facilitate reform. Like most modern economies, South Africa is increasingly relying on indirect taxation. The combined revenue generated by VAT, excise taxes, and the fuel and gas levy, make up 35% of total revenue. In the light of growing income inequality, this development is remarkable as wealthy individuals tend to spend a smaller proportion of their income on consumption. Indirect taxation thus potentially places a relatively higher burden on the poor. To counteract an aggravation of income inequality, a range of commodities, held to be important for the poor, are currently zero-rated under South Africa's VAT system. And some studies find that this policy measure is partly effective in reducing the regressive effect (Fourie and Owen, 1993; Jansen et al., 2012). However, while studies on the regressive effect of VAT are potentially valuable, they are certainly non-conclusive in appraising the welfare consequences of zero-ratings. Increasing the rates on such commodities would not only entail an increased burden on the poor, but also an increase in governmental revenues. Depending on the redistribution of such additional revenues, the poor could either benefit or not from this reform and the conclusion would be fairly independent from the overall regressiveness of the system. In this paper, we re-evaluate the effectiveness of zero-rating as a measure to alleviate poverty in South Africa and extend earlier work by incorporating both sides of fiscal action in our analysis. We clarify the interlink between welfare effects and consumption taxation by retracing a simple model developed by Keen (2013), in Section 2, which we then apply to the South African case. In doing so, we employ data from the most recent Income and Expenditure survey to derive distributions of household spending and governmental spending in Section 3. We conclude in Section 4. (authors' abstract) / Series: WU International Taxation Research Paper Series

If interpreted in a strict legal sense, beneficial ownership rules in tax treaties would have no effect on conduit companies because companies at law own their property and income beneficially. Conversely, a company can never own anything in a substantive sense because economically a company is no more than a congeries of arrangements that represents the people behind it. Faced with these contradictory considerations, people have adopted surrogate tests that they attempt to employ in place of the treaty test of beneficial ownership. An example is that treaty benefits should be limited to companies that are both resident in the states that are parties to the treaty and that carry on substantive business activity. The test is inherently illogical. The origins of the substantive business activity test appear to lie in analogies drawn with straw company and base company cases. Because there is no necessary relationship between ownership and activity, the test of substantive business activity can never provide a coherent surrogate for the test of beneficial ownership. The article finishes with a Coda that summarises suggestions for reform to be made in work that is to follow. (authors' abstract) / Series: WU International Taxation Research Paper Series

Cette thèse a été financée par l’équipementier automobile Cooper Standard afin de développer des éléments de pièces automobiles en polypropylène (PP) renforcés par des fibres végétales. Son objectif majeur est d’identifier les paramètres clés permettant l’obtention de composites performants pour ensuite les développer industriellement. Une grande diversité de parois végétales a été testée mécaniquement, étape primordiale pour l’analyse du comportement des composites. Les fibres sélectionnées ont ensuite été mélangées au PP et l’étude du compoundage a mis en évidence son impact sur les propriétés des futurs composites et la difficulté de mélanger des fibres végétales dans une matrice fondue. Les compounds PP/fibres végétales ont ensuite été transformés par extrusion et les travaux menés ont permis de développer des composites renforcés par des fibres de bois respectant le cahier des charges de Cooper Standard. Une comparaison entre l’injection et l’extrusion a souligné l’effet de la mise en œuvre sur les propriétés mécaniques et la microstructure des composites. Des composites modèles unidirectionnels renforcés par des fibres longues ont permis de comprendre les mécanismes de renforcement d’une matrice polypropylène par des fibres végétales de jute et de lin, et ont mis en évidence l’importance des propriétés mécaniques des constituants. Au contraire des composites injectés et renforcés par des fibres courtes de lin et de jute ont, eux, montré la prépondérance de la microstructure, par rapport aux performances des fibres, sur les propriétés mécaniques des pièces / This thesis was funded by the automotive supplier Cooper Standard to develop auto parts in polypropylene (PP) reinforced with plant fibers. Its major objective is to identify key parameters for obtaining high performance composites and then develop industrially. A great variety of plant cell walls was tested mechanically, critical step for the composite behavior analysis. The selected fibers were then mixed in PP and the study of compounding highlighted its impact on the properties of future composite and the difficulty of mixing plant fibers into a molten matrix. The compounds PP / vegetal fibers were then processed by extrusion and the work carried out has allowed the development of composite reinforced with wood fibers respecting the specifications of Cooper Standard. A comparison between extrusion molding and injection molding has showed the effect of molding process on mechanical properties and microstructure of composites. Unidirectional composites models reinforced with long fibers helped to understand the mechanisms of strengthening of a polypropylene matrix with jute and flax fibers, and highlighted the importance of constituents’ mechanical properties. Unlike injected composites and reinforced by short jute and flax fibers have them, showed the predominance of microstructure, compared with the performance of the fibers, on the mechanical properties of the parts.

[EN] The injection process is a very important part of the manufacture of thermoplastics. They are used for the fabrication of a wide variety of products because they comply perfectly with the overall objectives of low cost, precise size and almost the complete elimination of defects in the finished product. Many publications and scientific studies have been completed about the determination and control of the set of variables that affect the above-mentionned technological process. There are more and more applications for thermoplastics in a variety of areas such as the automotive and sports sectors. This thesis researches if computer programs can predict the behavior of materials that are used in the injection process. The quality of the predictive data depends on the properties of the materials injected, the variables of the tests and the mathematic models that can be used to simulate the behavior. Thanks to the simulation process, results can be combined and ordered so they can be used for comparison in real trials and they can be analyzed in order to confirm the conclusions on the behavior. / [ES] Dentro de los procesos de conformado de los termoplásticos destaca por su importancia industrial el proceso de Inyección. Se emplea para la fabricación de una gran diversidad de productos debido a que cumple perfectamente con los objetivos globales de minimización de costes económicos, errores dimensionales finales y práctica desaparición de defectos en las piezas terminadas. Se han realizado muchas publicaciones y estudios científicos para la determinación y control del conjunto de variables que afectan a dicho proceso de transformación. Este estudio busca dar un paso más en la generación de conocimiento, ya que se han detectado posibilidades de empleo de materiales termoplásticos bimateriales en el sector deportivo y en el de accesorios de automoción, siendo necesario el estudio y determinación de las posibilidades reales de empleo de programas informáticos de simulación en este tipo de piezas coinyectadas para la predicción del comportamiento mecánico en este tipo de procesos específicos. La calidad predictiva de las informaciones técnicas obtenidas depende de las propiedades de los materiales a coinyectar, variables de los ensayos y de los modelos matemáticos susceptibles de empleo para la simulación del comportamiento. Permitirá aglutinar de forma ordenada los resultados obtenidos mediante el proceso simulado, para su comparación con los ensayos reales para su análisis y obtención de conclusiones. / [CAT] Dins dels processos de conformat dels termoplàstics destaca per la seva importancia industrial el procés de Injecció. S'utilitza per a la fabricació d'una gran diversitat de productes donat que compleix perfectament amb els objectius globals de minimització de costos econòmics, errors dimensionals finals i pràctica desaparició de defectes en les peces acabades. S'han realitzat moltes publicacions i estudis científics per a la determinació i control del conjunt de variables que afecten aquest procés de transformació. Aquest estudi busca donar un pas més enllà a la generació de coneixement, ja que s'han detectat possibilitats d'ocupació de materials termoplàstics constituïts per dos materials al sector esportiu i al d'accessoris d'automoció. Es fá, per tant, necessari l'estudi i determinació de les possibilitats reals d'ocupació de programes informàtics de simulació en aquest tipus de peces coinyectadas per a la predicció del comportament mecànic en aquest tipus de processos específics. La qualitat predictiva de les informacions tècniques obtingudes depèn de les propietats dels materials a coinyectar, variables dels assajos i dels models matemàtics susceptibles d'ocupació per a la simulació del comportament. Ens permetrà aglutinar de forma ordenada els resultats obtinguts mitjançant el procés simulat, per la seva comparació amb els assajos reals per a la seva anàlisi i obtenció de conclusions. / Martínez Sanz, AV. (2016). Modelado y verificación experimental del comportamiento a traccion de probetas bimaterial termoplasticas. (PP-PE y ABS-HIPS) [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/61970 / TESIS

No description available.

This thesis investigates and documents the existence of preposition stranding in a dialect of Canadian French. The French spoken in the small Franco-Ontarian town of Lafontaine (LFF) allows prepositions to be stranded (i.e. without a following overt complement) in various scenarios. Taking bona fide P-stranding to be derivable only via leftward movement of prepositional complements, I show that LFF has true P-stranding equivalent to that observed in English. I argue that although LFF parallels Standard French in having orphan prepositions–where this phenomenon is best analyzed as non-movement derived P-stranding with the gap following the preposition being the instantiation of a null pronoun (Authier 2016; Zribi-Hertz 1984)–it is incontrovertible that P-stranding takes place under syntactic movement in LFF (e.g. wh-movement). Following Abels (2003b, 2012), I assume that prepositions constitute phase heads and their complements cannot be extracted without violating the principle of anti-locality. My central argument in this thesis is that in order to void violations of anti-locality, PPs in P-stranding languages must contain an extra layer of structure between prepositions and their complements in order to allow extraction. Evidence for this extra layer of structure is found in LFF in the form of the invariant morpheme de-nwhich appears on the prepositions dans, sur and sous when these are used in stranding constructions (e.g. dedans). Again, following Abels (2012), I label the de- element that appears on these prepositions under stranding as a ‘DR-morpheme’; this morpheme constitutes the head of a DRP which intervenes between prepositions and their complements, allowing extraction. I further show that evidence for the existence of bona fide P-stranding in LFF comes in the form of the ability to strand prepositions under ellipsis in this dialect. LFF, like English, allows prepositions to be stranded in swiping constructions, where swiping is a sub form of sluicing wherein a prepositions and its wh-complement surface in inverse order (e.g. `who from’/qui de) as the sole remnants of ellipsis. Given the existence of swiping in LFF, I discuss certain ramifications this has for current theories of sluicing and swiping, ultimately arguing that swiping in LFF is best analyzed as being derived via deleting prosodically redundant material between a wh-phrase which has moved to the left periphery, and its selecting preposition which has been left stranded in its base position.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Neste trabalho foram preparados nanocompósitos de elastômeros termoplásticos à base de PP/EPDM/argila organofílica. Foram utilizados como agentes interfaciais polipropileno e terpolímero de etileno-propileno-dieno ambos modificados com grupos anidrido maleico, PP-MA e EPDM-MA, respectivamente. Dois tipos de argila organofílica, que se diferenciam pela estrutura química do surfactante e conseqüentemente pela estabilidade térmica, foram empregados como carga inorgânica. Os nanocompósitos foram preparados pela técnica de intercalação por fusão em câmara interna de mistura e a incorporação da argila foi feita pela adição de masterbatches previamente preparados. Foram investigadas as propriedades de tração, reométricas e ainda a morfologia (cristalinidade e estrutura obtida) dos nanocompósitos a fim de estabelecer a influência do tipo e quantidade de argila organofílica e agente interfacial. Os resultados mostraram que a adição de agente interfacial melhorou a dispersão da argila organofílica na matriz de PP/EPDM, particularmente o PP-MA. Foram obtidos nanocompósitos com estruturas mistas intercaladas e esfoliadas, que resultaram em maiores valores de módulo de elasticidade e manutenção dos valores de deformação. As propriedades reométricas confirmaram o maior grau de dispersão da argila organofílica em nanocompósitos contendo PP-MA. Teores crescentes de argila reduziram a cristalinidade dos nanocompósitos, os quais quando reprocessados, mantiveram as características inerentes ao TPE de origem. Por fim, a estrutura do surfactante presente / In this work it was prepared nanocomposites based in PP/EPDM thermoplastic elastomer and organoclay. Maleinized polypropylene and ethylene-propylene-diene rubber, PP-MA and EPDM-MA, respectively, were employed as interfacial agents. Also two kinds of organoclays, differing about surfactant chemical structure and as consequence thermal stability, were investigated as inorganic filler. Nanocomposites were prepared by melt intercalation in an internal chamber mix and organoclay was incorporated by masterbatches addition, which ones were previously made. It was investigated the influence of amount and kind of organoclay and interfacial agent on tensile properties, rheology and morphology (crystallinity and structure type) of nanocomposites obtained. The results showed that interfacial agents addition promoted a better dispersion degree of organoclay platelets in PP/EPDM matrix, mainly PP-MA. Nanocomposites with both intercalated and exfoliated structures were obtained. These exhibited higher Young modulus and kept their elongation values. The better dispersion degree of clay platelets in nanocomposites containing PP-MA was confirmed by rheology measurements. Increasing amounts of organoclay lowered the crystallinity degree of nanocomposites but the reprocessability was maintained similar to that of pure TPE. Finally, the chemical structure of surfactants did not change the intercalation/exfoliation process due to the similarity of organoclay basal spacing and moderated TPE processing temperature.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Neste trabalho foram preparados nanocompósitos de elastômeros termoplásticos à base de PP/EPDM/argila organofílica. Foram utilizados como agentes interfaciais polipropileno e terpolímero de etileno-propileno-dieno ambos modificados com grupos anidrido maleico, PP-MA e EPDM-MA, respectivamente. Dois tipos de argila organofílica, que se diferenciam pela estrutura química do surfactante e conseqüentemente pela estabilidade térmica, foram empregados como carga inorgânica. Os nanocompósitos foram preparados pela técnica de intercalação por fusão em câmara interna de mistura e a incorporação da argila foi feita pela adição de masterbatches previamente preparados. Foram investigadas as propriedades de tração, reométricas e ainda a morfologia (cristalinidade e estrutura obtida) dos nanocompósitos a fim de estabelecer a influência do tipo e quantidade de argila organofílica e agente interfacial. Os resultados mostraram que a adição de agente interfacial melhorou a dispersão da argila organofílica na matriz de PP/EPDM, particularmente o PP-MA. Foram obtidos nanocompósitos com estruturas mistas intercaladas e esfoliadas, que resultaram em maiores valores de módulo de elasticidade e manutenção dos valores de deformação. As propriedades reométricas confirmaram o maior grau de dispersão da argila organofílica em nanocompósitos contendo PP-MA. Teores crescentes de argila reduziram a cristalinidade dos nanocompósitos, os quais quando reprocessados, mantiveram as características inerentes ao TPE de origem. Por fim, a estrutura do surfactante presente / In this work it was prepared nanocomposites based in PP/EPDM thermoplastic elastomer and organoclay. Maleinized polypropylene and ethylene-propylene-diene rubber, PP-MA and EPDM-MA, respectively, were employed as interfacial agents. Also two kinds of organoclays, differing about surfactant chemical structure and as consequence thermal stability, were investigated as inorganic filler. Nanocomposites were prepared by melt intercalation in an internal chamber mix and organoclay was incorporated by masterbatches addition, which ones were previously made. It was investigated the influence of amount and kind of organoclay and interfacial agent on tensile properties, rheology and morphology (crystallinity and structure type) of nanocomposites obtained. The results showed that interfacial agents addition promoted a better dispersion degree of organoclay platelets in PP/EPDM matrix, mainly PP-MA. Nanocomposites with both intercalated and exfoliated structures were obtained. These exhibited higher Young modulus and kept their elongation values. The better dispersion degree of clay platelets in nanocomposites containing PP-MA was confirmed by rheology measurements. Increasing amounts of organoclay lowered the crystallinity degree of nanocomposites but the reprocessability was maintained similar to that of pure TPE. Finally, the chemical structure of surfactants did not change the intercalation/exfoliation process due to the similarity of organoclay basal spacing and moderated TPE processing temperature.

Made available in DSpace on 2016-03-15T19:36:30Z (GMT). No. of bitstreams: 1 Tiago Martinez Regis.pdf: 4801138 bytes, checksum: 5f81ded531050d67c7062c6e5ce4a899 (MD5) Previous issue date: 2011-02-08 / The main objective of this work was study the possibility of using a fillers hybrid consisting of calcium carbonate, and micronized rubber waste obtained from discarded tires after use, dispersed in the matrix of recycled polypropylene. The composites were prepared with different concentrations of loads: 30% of rubber waste + 10% CaCO3 20% waste rubber + 7.5% CaCO3, 10% of waste rubber + 5% CaCO3; only 20% CaCO3, and only 20% of rubber waste. The composites were characterized by rheological tests, by measurements of flow index (ASTM D 1238) and dynamic-mechanical analysis (DMA), for mechanical tests of tensile strength (ASTM D 638), three point bending (ASTM D 790), Izod impact (ASTM D 256) and Shore D hardness (ASTM D 2240), heat deflection temperature under load (ASTM D 648), Vicat softening point (ASTM D 1525). Were also made images of the fracture surface by MEV (scanning electron microscope). Comparing the results of tensile strength tests, was observed that the use of these different loads, occurred a decrease of the tensile strength until failure. The flow index showed a considerable decrease with addition of loads, both in the composites as in the hybrids. The elastic modulus increased with the addition of calcium carbonate, the material became more rigid. The addition of rubber made the modulus decreased considerably, the material became less rigid. The images obtained by MEV could confirm the poor adhesion between polymer matrix and the particles of CaCO3 and waste rubber. The work showed that with the hybrid composites from different concentrations, occurred significant changes in the composites and hybrids properties. About the cost analysis, the study showed that the use of hybrid loads in recycled polypropylene thermoplastic resin becomes advantageous when the cost difference between the recycled resin, without charge, and the hybrid composites, is considerable. In point of view of environment preserving, the use of recyclable materials as raw for the production of new products, becomes a practical solution to obtain compatibility and harmony between development and environmental quality, in other words, sustainable development. / Este trabalho teve por objetivo estudar a possibilidade de utilizar-se um híbrido de cargas, constituído pela carga mineral carbonato de cálcio e por resíduos de borracha micronizada obtidos a partir de pneus descartados após uso, dispersas na matriz de polipropileno reciclado. Os compósitos obtidos foram preparados com diferentes concentrações de cargas: 30% de resíduos de borracha + 10 % de CaCO3; 20% de resíduos de borracha + 7,5% de CaCO3; 10% de resíduos de borracha + 5% de CaCO3; somente 20% de CaCO3, e somente 20% de resíduos de borracha. Os compósitos obtidos foram caracterizados, através de ensaios reológicos, por medidas de índice de fluidez (ASTM D 1238) e análise dinâmico-mecânica (DMA); por ensaios mecânicos de resistência a tração (ASTM D 638), flexão em três pontos (ASTM D 790), resistência ao impacto Izod (ASTM D 256) e dureza shore D (ASTM D 2240); por ensaios térmicos como, deflexão térmica ao calor sob carga (ASTM D 648) e ponto de amolecimento vicat (ASTM D 1525). Também foram feitas imagens da superfície de fratura das amostras através do MEV (microscópio eletrônico de varredura). Comparando-se os resultados dos ensaios de resistência a tração das amostras, observou-se que com a utilização dessas diferentes cargas, ocorreu uma diminuição da resistência à tração na ruptura. O índice de fluidez apresentou considerável diminuição em seus índices com o aumento da adição das cargas, tanto nos compósitos quanto nos híbridos. O módulo elástico das amostras carregadas aumentou com a adição de carbonato de cálcio, tornou o material mais rígido, a adição de borracha fez com que o módulo de elasticidade das amostras diminuísse consideravelmente, tornou o material menos rígido. As imagens obtidas através do MEV puderam comprovar a pouca adesão entre a matriz polimérica e as partículas de CaCO3 e de resíduo de borracha. O trabalho mostrou que com a formação de compósitos híbridos a partir das diferentes concentrações das cargas utilizadas, ocorreram alterações significativas nas propriedades dos compósitos e dos híbridos, obtidos. Com relação à análise de custos, o trabalho mostrou que a utilização de cargas híbridas na resina termoplástica de polipropileno reciclado torna-se vantajosa quando a diferença de custos entre a resina reciclada, sem carga, e os compósitos híbridos, seja considerável. Do ponto de vista da conservação do Meio Ambiente, a utilização de materiais recicláveis como matérias-primas, para a produção de novos artefatos, torna-se uma solução prática para obter compatibilidade e harmonia entre desenvolvimento e a qualidade do meio ambiente, ou seja, desenvolvimento sustentável.

L’expérience ALICE a pour principal objectif l’étude et la caractérisation du plasma de quarks et de gluons (QGP), un état de la matière nucléaire dans lequel les quarks et les gluons sont déconfinés. Les quarkonia constituent l’une des plus intéressantes sondes (des états liés d’un quark lourd Q et de son anti-quark Q) du QGP. De plus, l’étude de la production des quarkonia est très intéressante puisqu’elle peut contribuer à une meilleure compréhension de la Chromodynamique Quantique, la théorie décrivant l’interaction forte. La formation d’états de quarkonia lors de collisions hadroniques n’est pas bien comprise. Les deux principales approches théoriques décrivant la production d’états de quarkonia, le ‘Color Singlet Model’ (CSM) et la QCD non-relativiste (NRQCD), ont montré des difficultés à décrire simultanément la section efficace de production et la polarisation de tels états. Expérimentalement, les mesures de la polarisation des quarkonia n’ont pas toujours été compatibles entre elles. Ainsi, que ce soit du point de vue expérimental ou théorique, l’étude des quarkonia est restée inachevée. De nouvelles méthodes récemment proposées ont souligné la nécessité de mesurer tous les paramètres de la polarisation, dans les différents systèmes de référence. Dans ce contexte, de nouvelles mesures peuvent améliorer les contraintes actuelles, voire apporter de nouvelles contraintes sur les prédictions. ALICE a mesuré la polarisation du J/ψ lors de collisions pp à √8 = 7 TeV. La plus grande statistique des données à 8 TeV par rapport aux données à 7 TeV permet d’étendre les mesures à une gamme de pT plus large. Cette thèse présente une mesure complète de la polarisation de J/ψ, i.e. les trois paramètres de polarisation, dans deux systèmes de référence différents: le système Collins-Soper et le système d’hélicité. Les résultats ne montrent aucune polarisation significative pour le J/ψ dans le domaine cinématique étudié : 2.5 < y < 4.0 et 2 < pT < 15 GeV/c. Le paramètre invariant λ a également été mesuré afin d’écarter le risque d’un biais dans la procédure d’analyse. La comparaison de ces résultats avec les prédictions théoriques montre que la production de quarkonia n’est pas encore correctement décrite. Aucun de ces modèles théoriques n’est capable de décrire à la fois les mesures de sections efficaces et de polarisation. / The main purpose of the ALICE experiment is the study and characterization of the Quark Gluon Plasma (QGP), a state of nuclear matter in which quarks and gluons are deconfined. Quarkonia (bound states of a heayvy quark Q and its anti-quark Q) constitute one of the most interesting probes of the QGP. Besides this motivation, the study of quarkonium production is very interesting since it can contribute to our understanding of Quantum Chromodynamics, the theory of strong interactions. The formation of quarkonium states in hadronic collisions is not yet completely understood. The two main theoretical approaches to describe the production of quarkonium states, the Color Singlet Model and the Non-Relativistic QCD framework (NRQCD), have historically presented problems to simultaneously describe the production cross section and polarization of such states. On the experimental side, quarkonium polarization measurements have not always been complete and consistent between them. So, neither from the theoretical nor from the experimental point of view the situation was clear.Improved methods for the measurement of quarkonium polarization have been recently proposed, highlighting the necessity to perform the measurements of all polarization parameters with respect to different reference axes. In this context, new measurements could help to improve and set new constraints to the calculations. ALICE has measured the J/ψ polarization in pp collisions at √8= 7 TeV. The higher statistics of the 8 TeV data with respect to the 7 TeV data allows to extend the pT range of the measurements. This thesis presents a complete measurement of J/ψ polarization, i.e. the three polarization parameters, in two polarization frames : the Collins-Soper and Helicity frames. The results show no significant J/ψ polarization in the kinematic domain studied: 2.5 < y < 4.0 and 2 < pT < 15 GeV/c. The measurement of a frame invariant parameter λ, was also performed to ensure that no bias was present in the analysis procedure. The comparison with different theoretical predictions shows that there is not yet a satisfactory description of quarkonium production. None of the present theoretical approaches is able to describe both, the cross section and polarization measurements.