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STRATIGRAPHIC, GEOCHEMICAL, AND GEOCHRONOLOGICAL ANALYSIS OF THE WOLFCAMP-D INTERVAL, MIDLAND BASIN, TEXASPerlman, Zachary S. 01 January 2017 (has links)
Subsurface data derived from ~388 ft of drill core from Martin County (TX) were used to understand the depositional setting of the Wolfcamp-D, a petroleum producing interval in the Midland Basin. Elemental geochemistry collected via x-ray fluorescence revealed a highly variable depositional history marked by the deposition of diverse siliciclastic and carbonate lithofacies. Integration of multiple datasets resulted in the interpretation of nine lithofacies, whose deposition appears cyclical. Correlations between molybdenum and total organic carbon indicate slow recharge of bottom waters and anoxic/euxinicconditions within the basin. The presence of phosphatic nodules coinciding with siliceous black mudrocks suggested high levels of primary productivity driven by upwelling. High-frequency sea level variability, driven by far-field glaciation and regional paleoclimate, were key controls on both the chemostratigraphy and lithofacies. Along-strike variability is seen throughout the basin due to paleobathymetry, proximity and connections to paleochannels, and localized structures. Rhenium-osmium (Re/Os) geochronology was conducted on siliceous mudrocks with high total organic carbon. A depositional age of 300 ± 18 Ma was obtained, partially confirming previous correlations to shelf biostratigraphic data. Scatter in the Re/Os data is likely due to mixing in the basin or non-hydrogenous Os incorporated into the analysis due to the method of preparation.
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Global Spillover Effects from Unconventional Monetary Policy During the CrisisSolís González, Brenda January 2015 (has links)
This work investigates the international spillover effects and transmission channels of Unconventional Monetary Policy (UMP) of major central banks from United States, United Kingdom, Japan and Europe to Latin-American countries. A Global VAR model is estimated to analyze the impact on output, inflation, credit, equity prices and money growth on the selected countries. Results suggest that indeed, there are international spillovers to the region with money growth, stock prices and international reserves as the main transmission channels. In addition, outcomes are different between countries and variables implying not only that transmission channels are not same across the region but also that the effects of the monetary policy are not distributed equally. Furthermore, it is found evidence that for some countries transmission channels may have transformed due to the crisis. Finally, effects of UMP during the crisis were in general positive with exception of Japan indicating that policies from this country brought more costs than benefits to the region. Keywords Zero Lower Bound, Unconventional Monetary Policy, International Spillovers, Global VAR, GVAR.
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Estudo da supercondutividade nos sistemas intermetálicos não-centrossimétricos de composição YCo1-xC2 e Lu1-xThxNiC2 / Analysis of the superconductivity in the intermetallic noncentrosymmetric systems YCo1-xC2 and Lu1-xThxNiC2Velazquez, Orlando Cigarroa 20 November 2015 (has links)
Recentemente, os compostos não-centrossimétricos têm sido intensamente estudados devido à grande variedade de comportamentos magnéticos, os quais são induzidos pela ausência de centro de simetria na sua estrutura cristalográfica. Esta assimetria induz uma modificação na estrutura de bandas, causando um acoplamento spin-orbita antissimétrico quem é responsável por mecanismos de interação magnética inusuais. A supercondutividade em este tipo de compostos apresenta propriedades que divergem do comportamento esperado pela teoria BCS. Neste trabalho será apresentado um estudo sobre a investigação de supercondutividade em dois sistemas ternários, Y-Co-C e Lu-Ni-C particularmente nos compostos YCo1-xC2 e Lu1-xThNiC2. Estes compostos cristalizam na estrutura CeNiC2 de simetria ortorrômbica é do grupo espacial 38 Amm2 que não possui centro de inversão. As técnicas de caracterização usadas neste trabalho incluem medidas de magnetização, resistividade e calor especifico como funções da temperatura, assim como magnetização como função do campo magnético aplicado. O composto YCo0.7C2 é supercondutor com Tc = 4 K e exibe um comportamento que diverge da teoria BCS. As medidas realizadas neste trabalho sugerem que este material é um forte candidato como supercondutor não convencional, onde poderia existir uma mistura de contribuições nos canais singleto e tripleto. No caso do sistema Lu1-xThxNiC2 os resultados preliminares indicam claramente supercondutividade nos compostos dopados com Th, onde a composição Lu0.6Th0.4NiC2 apresenta uma Tc= 8 K. / In recent years, non-centrosymmetric compounds have attracted a great interest because of their wealth variety of topical behaviors, induced by the lack of the inversion center on the crystallographic structure. This asymmetry leads to a strong modification in the band structures, causing an antisymmetric spin-orbit coupling which is responsible for unusual magnetic interaction mechanisms. Superconductivity in compounds whose crystal structure lacks inversion symmetry are known to display intriguing properties that deviate from conventional BCS superconducting behavior. Here we report the analysis of the ternary systems Y-Co-C and Lu-Ni-C, We focused our analysis in the intermetallic compounds YCo1-xC2 and Lu1-xThxNiC2. Magnetization, resistivity, and heat capacity measurements on polycrystalline samples of noncentrosymmetric YCo0.7C2, showing clear evidence of bulk superconductivity with a critical temperature of Tc =4 K. Interestingly the specific heat of the superconducting state deviates from conventional exponential temperature dependence, which is suggestive of possible unconventional superconducting behavior in YCo0.7C2, similar to that seen in the isostructural and isoelectronic superconductor LaNiC2. Besides, these results strongly suggest that this material is a strong candidate of multiband superconductivity. In the case of the system Lu1- xThxNiC2 our results showed a clear superconducting signal in the Th doped samples, where the composition Lu0.6Th0.4NiC2 has a Tc= 8 K.
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[en] PRESSURE-TEMPERATURE-COMPOSITION PHASE DIAGRAM OF THE HEAVY FERMION COMPOUND CE2RH(1−X)IR(X)IN8 / [pt] DIAGRAMA DE FASES PRESSÃO-COMPOSIÇÃO-TEMPERATURA DO COMPOSTO FÉRMION PESADO CE2RH(1−X)IR(X)IN8EDUARDO NOVAES HERING 11 January 2007 (has links)
[pt] Compostos férmions pesados se distinguem dos metais típicos
em baixas temperaturas, onde fenômenos decorrentes da alta
correlação entre os elétrons de condução e os elétrons f
dos íons da rede se tornam evidentes. Fatores como uma
massa eletrônica efetiva centenas de vezes maior que
a massa do elétron livre e a coexistência de ordem
magnética com um estado supercondutor atraem interesse
crescente para estes materiais. A aplicação de pressão
torna possível sintonizar a temperatura de transição
antiferromagnética em alguns destes compostos até o zero
absoluto, onde flutuações qüânticas se tornam relevantes e,
dependendo do composto, um estado supercondutor não
convencional pode se manifestar. Neste trabalho,
resultados de medidas de resistência elétrica sob pressão
realizadas nos compostos Ce2Rh1−xIrxIn8 são apresentados em
diagramas de fases do tipo pressão-temperatura para cada
valor de x estudado, e em diagramas do tipo composição-
temperatura para algumas pressões representativas. Duas
fases supercondutoras são identificadas nos compostos, uma
delas induzida, e a outra suprimida pela pressão aplicada.
A primeira das fases parece estar relacionada com
flutuações magnéticas, enquanto a origem da segunda
pode estar relacionada com flutuações de valência. Outras
características interessantes podem ser observadas nos
diagramas obtidos, como uma possível fase supercondutora
reentrante em x = 0.25 e a brusca supressão
de supercondutividade em valores de x maiores que 0,8. / [en] Heavy fermion compounds behave differently from typical
metals at low temperatures, where the phenomena that arise
due to the correlation between conduction electrons and the
f ions of the lattice become evident.
An increased effective electronic mass that can reach
values as high as hundreds of times the free electron mass
and the coexistence of magnetic order
with a superconducting state attract growing interest to
these materials. When external pressure is applied on some
of those systems, the antiferromagnetic transition
temperature can be tuned towards absolute zero, where
quantum critical fluctuations become relevant and,
depending on the compound studied, an unconventional
superconducting state can manifest itself. In this work,
measurements of electrical resistance were made on the
compounds Ce2Rh1−xIrxIn8 and the results were expressed as
pressure-temperature phase diagrams for each value of x
studied. Temperature-composition phase diagrams for
representative pressures were also built. Two
superconducting phases can be identified on the
Ce2Rh1−xIrxIn8 system, one of them induced and the other
supressed by applied pressure. The first one seems to be
related to magnetic spin fluctuations while the second
one can be related to valence fluctuations. Other
interesting features can be observed on the obtained
diagrams, like a possible reentrant superconducting
phase at x = 0.25 and the abrupt supression of
supercunductivity on values above x = 0.8.
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Meandros da interpretação: os textos e seus leitores / Meanders in interpretation: texts and their readersPereira, Carolina de Jesus 14 September 2016 (has links)
Esta dissertação explora ocorrências de leitura não convencional, deslizes cometidos por leitores ao entrar em contato com textos. Mesmo fugindo de uma abordagem moralista e classificatória, foi levada em conta a diferença entre o trabalho realizado por sujeitos que já podem ser considerados leitores competentes daquele empreendido por leitores que carecem de maior aprofundamento em sua educação. Isso posto, é preciso esclarecer que as ocorrências de deslizes foram consideradas parte do processo de construção de conhecimento (ESTEBAN, 2000, 2001; SUASSUNA, 2004), razão por que nossa tentativa de interpretar as formulações desviantes e suas causas visava romper com a lógica do fracasso e, em seu lugar, buscar uma problematização que pudesse resultar na criação de novos saberes. O corpus foi constituído por materiais de duas naturezas: a) notícias; e b) textos publicados na internet e os comentários a respeito deles publicados pelos leitores. Com base em um referencial teórico que contemplava diferentes vertentes do estudo da leitura (GREIMAS, 1979; MARCUSCHI, 1985; FREIRE, 1991; GERALDI, 1993, 1996; SOLÉ, 1998; BRANDÃO, 1998; CARDOSO, 1999; POSSENTI, 2002, 2009; SMITH, 2003; BARZOTTO, 2009; MARCUSCHI, 2009; RIOLFI, 2015), buscou-se recuperar o percurso que levou alguém a ler de modo não convencional. Algumas das fontes de leituras não convencionais que se tornaram visíveis com o aprofundamento da análise foram elementos linguísticos como incompreensão de temporalidade e conjugação verbal, dificuldade de partilhar ironia, atribuição inexata de sentidos a palavras polissêmicas e desconhecimento dos efeitos de sentido gerados por conjunções e locuções conjuntivas. Entre os elementos extratextuais, destacamos o alheamento ao conteúdo do texto, quando o leitor parece tirar conclusões com base em manchetes; o viés de confirmação, quando a pessoa só lê para confirmar o que já estava procurando, e a interferência de crenças, experiências e ideias individuais. Concluímos que, para evitar que as leituras desviantes coloquem em risco a própria elaboração intelectual, como alertou Riolfi (2015), é urgente que, na escola, tome-se a leitura como objeto prioritário. Em vista disso, cabe aos professores instruir seus alunos de modo a ressignificar a relação entre textos e leitores e, assim, redefinir os meandros da interpretação. / This investigation focuses on unconventional reading occurrences, slips committed by readers when reading texts. Even though we avoid a moralistic and classificatory approach, we took into account the difference between the work performed by individuals who may already be considered competent readers and the one performed by readers who lack a deepening in their education. The idea that these slips in reading are considered part of the knowledgebuilding process (ESTEBAN, 2000, 2001; SUASSUNA, 2004) is essential to this study. Thats the reason why our attempt to interpret the deviant formulations and their causes is intended to break with the logic the failure and, instead, seek a questioning that can result in the creation of new knowledge. The corpus consisted of two kinds of materials: a) news; and b) texts published on the Internet and comments about them posted by readers. Based on a theoretical framework which included different theories about Reading (GREIMAS, 1979; MARCUSCHI, 1985; FREIRE, 1991; GERALDI, 1996; SOLÉ, 1998; BRANDÃO, 1998; CARDOSO, 1999; POSSENTI, 2002, 2009; Smith, 2003; BARZOTTO 2009; MARCUSCHI, 2009; RIOLFI, 2015), we sought to recover the path that led a person to read as they did. Some of the causes of unconventional readings that became visible in the analysis were linguistic elements such as incomprehension of verb conjugation, difficulty to understand irony, inaccurate attribution of meanings to polysemous words and unfamiliarity with the meanings created by conjunctions. Among extra-textual elements, we highlight the aloofness regarding the content of the text, when the reader seems to draw conclusions based on headlines; the confirmation bias, when one reads only to confirm what they already thought about something, and the interference of beliefs, experiences and individual ideas. We concluded that, in order to prevent that deviant readings put intellectual development in danger, as Riolfi (2015) suggested, it is urgent that schools take reading as a priority. Therefore, teachers must instruct their students so that the relationship between texts and readers can be reframed, which will thus redefine the meanders of interpretation.
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A representação gráfica da oralidade em blogs idol japoneses / The graphical representation of orality in Japanese idol blogsAizawa, Erina Akemi 28 September 2016 (has links)
O objetivo do presente trabalho é fazer um estudo sobre as formas de representação da língua falada japonesa nos textos de blogs do gênero idol e as estratégias utilizadas por suas escreventes na sua redação. Para isso, foi utilizado como corpus de análise os dados linguísticos presentes nas postagens desses blogs. Destaque-se que, para a produção de textos em língua japonesa, os escreventes encontram disponíveis quatro sistemas de escrita (o hiragana, o katakana, o kanjie o rmaji), além dos elementos suprassegmentais(sinais de pontuação, diacríticos etc.)que, juntos, oferecem uma variedade de recursos estilísticos e expressivos, os quais são amplamente aproveitados dentro dos textos. Utilizando-se dos blogs idol como cerne, serão feitas discussões acerca da representação da forma oral em seus textos para, em seguida, por meio da análise dos excertos das postagens, descrever os procedimentos linguísticos que resultam em uma língua falada por escrito na língua japonesa. / This work proposes to make a study about the forms of representation found in the Japanese spoken language on idol blog texts and the strategies used in theircomposition. For that purpose, blogs posts will be used as analytical corpus linguistic data. It is noteworthy that the writers have four writing systems at disposal to produce texts in Japanese language (hiragana, katakana, kanji and roomaji), in addition to supra-segmental elements (punctuation marks, diacritics etc.) which together offer a variety of stylistic and expressive resources that are widely used in texts. Using the idol blogs as basis, discussions will be made about the representation of the oral form in it\'s writings by analyzing the excerpts from posts to then describe the linguistic procedures that result in a \"spoken language in writing\" in Japanese.
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Essais sur l'impact des mesures de politique monétaire non conventionnelle dans la zone euro / Essays on the impact of unconventional monetary policies in the euro areaKanga, Kouamé Désiré 25 January 2017 (has links)
La crise financière et ´économique a remis en cause les modalités de mise en œuvre et de fonctionnement de la politique monétaire. Avant la crise, la politique monétaire était simplement retranscrite par une règle de taux d’intérêt. Désormais, les instruments et les canaux de transmission sont devenus complexes et les effets incertains. Dans cette perspective, cette thèse propose une évaluation théorique et empirique des politiques monétaires non conventionnelles dans l’environnement hétérogène qu’est la zone euro. Le chapitre 1 analyse les effets de ces politiques sur le coût du crédit aux entreprises. Nous montrons que les effets directs ont été limités. Néanmoins, les mesures non conventionnelles ont été efficaces dans l’accompagnement de la politique de taux zéro (effets indirects). Le chapitre 2 porte sur l’impact de ces politiques sur la courbe des taux et la prime souveraine. Nous montrons que ces mesures ont permis de réduire les primes. Toutefois, leur transmission est hétérogène entre les pays et dans le temps, suivant la perception des investisseurs. Nous ´étudions au chapitre 3 les conséquences macro-économiques et financières de ces politiques. Il ressort qu’elles se transmettent à l’économie par une hausse du prix des actifs suivie d’une baisse des taux d’intérêt. De ce fait, les conditions de crédit se sont assouplies, ce qui a relancé l’activité de financement bancaire. Ces politiques ont amélioré la compétitivité, stimulé la demande et augmenté le taux d’inflation. Néanmoins, leurs effets sur l’activité et les conditions d’offre et de demande de crédit sont lents dans certains pays. Dans le chapitre 4, nous montrons avec un modèle DSGE, qu’une forte capitalisation bancaire et un secteur bancaire en bonne santé renforcent la transmission des politiques non conventionnelles conformément à ce qui avait ´été trouvé empiriquement dans la première partie de la thèse. / The financial and economic crisis has challenged the implementation and the transmission channels ofthe monetary policy. Before the crisis, monetary policy was conducted through a simple interest rate rule.Now, instruments and channels of transmission have become complex and uncertain. In this perspective, thisthesis focuses on theoretical and empirical evaluation of unconventional monetary policies in the heterogeneousenvironment that is the euro area. Chapter 1 analyses the effects of these policies on the cost of credit toenterprises. We show that the direct effects have been limited. Nevertheless, unconventional policies havebeen effective in supporting the zero interest rate policy (indirect effects). Chapter 2 focuses on the effects ofthese policies on the yield curve and the sovereign premium. We point out that these policies have reducedpremiums. Their transmission is strongly influenced by the market expectations and heterogeneous acrosscountries and over time. We discuss in Chapter 3 the macroeconomic and financial implications of thesepolicies. We show that they increased asset prices and lowered interest rates. As a result, credit conditionswere relaxed, which boosted bank lending. These policies have improved the competitiveness of the country,increased output and inflation. However, their effects on the real activity, the credit standard and the creditdemand is slow in some countries. By using a DSGE model in Chapter 4, we find that a strong bankcapitalization and a healthy banking sector enhance the transmission of unconventional policies, in accordancewith what has been found empirically in the first part of the thesis.
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Estudo da supercondutividade nos sistemas intermetálicos não-centrossimétricos de composição YCo1-xC2 e Lu1-xThxNiC2 / Analysis of the superconductivity in the intermetallic noncentrosymmetric systems YCo1-xC2 and Lu1-xThxNiC2Orlando Cigarroa Velazquez 20 November 2015 (has links)
Recentemente, os compostos não-centrossimétricos têm sido intensamente estudados devido à grande variedade de comportamentos magnéticos, os quais são induzidos pela ausência de centro de simetria na sua estrutura cristalográfica. Esta assimetria induz uma modificação na estrutura de bandas, causando um acoplamento spin-orbita antissimétrico quem é responsável por mecanismos de interação magnética inusuais. A supercondutividade em este tipo de compostos apresenta propriedades que divergem do comportamento esperado pela teoria BCS. Neste trabalho será apresentado um estudo sobre a investigação de supercondutividade em dois sistemas ternários, Y-Co-C e Lu-Ni-C particularmente nos compostos YCo1-xC2 e Lu1-xThNiC2. Estes compostos cristalizam na estrutura CeNiC2 de simetria ortorrômbica é do grupo espacial 38 Amm2 que não possui centro de inversão. As técnicas de caracterização usadas neste trabalho incluem medidas de magnetização, resistividade e calor especifico como funções da temperatura, assim como magnetização como função do campo magnético aplicado. O composto YCo0.7C2 é supercondutor com Tc = 4 K e exibe um comportamento que diverge da teoria BCS. As medidas realizadas neste trabalho sugerem que este material é um forte candidato como supercondutor não convencional, onde poderia existir uma mistura de contribuições nos canais singleto e tripleto. No caso do sistema Lu1-xThxNiC2 os resultados preliminares indicam claramente supercondutividade nos compostos dopados com Th, onde a composição Lu0.6Th0.4NiC2 apresenta uma Tc= 8 K. / In recent years, non-centrosymmetric compounds have attracted a great interest because of their wealth variety of topical behaviors, induced by the lack of the inversion center on the crystallographic structure. This asymmetry leads to a strong modification in the band structures, causing an antisymmetric spin-orbit coupling which is responsible for unusual magnetic interaction mechanisms. Superconductivity in compounds whose crystal structure lacks inversion symmetry are known to display intriguing properties that deviate from conventional BCS superconducting behavior. Here we report the analysis of the ternary systems Y-Co-C and Lu-Ni-C, We focused our analysis in the intermetallic compounds YCo1-xC2 and Lu1-xThxNiC2. Magnetization, resistivity, and heat capacity measurements on polycrystalline samples of noncentrosymmetric YCo0.7C2, showing clear evidence of bulk superconductivity with a critical temperature of Tc =4 K. Interestingly the specific heat of the superconducting state deviates from conventional exponential temperature dependence, which is suggestive of possible unconventional superconducting behavior in YCo0.7C2, similar to that seen in the isostructural and isoelectronic superconductor LaNiC2. Besides, these results strongly suggest that this material is a strong candidate of multiband superconductivity. In the case of the system Lu1- xThxNiC2 our results showed a clear superconducting signal in the Th doped samples, where the composition Lu0.6Th0.4NiC2 has a Tc= 8 K.
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Contribution à létude de lalimentation de la pintade locale au Bénin, et perspectives daméliorations à laide de ressources non conventionnelles/Contribution to the study of local guinea fowl feeding in Benin and prospects for improvements with unconventional feedstuffsDahouda, Mahamadou 19 June 2009 (has links)
Cette étude propose des voies damélioration de lalimentation de la pintade locale à laide de ressources alimentaires non-conventionnelles au Bénin.
La première partie de ce travail fait le point sur lutilisation des ressources alimentaires non-conventionnelles et particulièrement des graines de Mucuna spp. dans lalimentation de la volaille. Elle envisage le contexte de leur utilisation, leurs valeurs nutritionnelles ainsi que les contraintes liées à leur valorisation avant denvisager les effets des diverses techniques de traitement sur la réduction des teneurs en diverses substances toxiques et sur leur composition chimique.
La seconde partie porte sur létude des élevages traditionnels et les compare à une forme délevage contrôlé en station. Au Bénin, comme dans la plupart des pays au Sud du Sahara, lélevage traditionnel de la volaille est caractérisé par un système extensif peu productif et divaguant, où les animaux se nourrissent essentiellement sur les parcours. Ils disposent dabris sommaires et exigus et ne bénéficient ni de programmes de prophylaxie sanitaire ni dune alimentation adaptée. Toutefois, certains éleveurs distribuent en supplément des céréales ou dautres ressources non conventionnelles. Dans ces conditions, les performances pondérales des pintades ont été de 1121 ± 100 g à six mois dâge. En milieu contrôlé, cest-à-dire où les animaux étaient logés en permanence, nourris à laide dune provende formulée, séparés par sexe et vermifugés, le poids moyen à âge identique des mâles a été de 1151 ± 108 g contre 1085 ± 74 g pour celui des femelles. Dans les élevages traditionnels, les animaux vermifugés ont présenté une supériorité pondérale (1221 ± 107 g) par rapport au groupe non traité (1007 ± 31 g). Les performances de croissance des oiseaux élevés en milieu contrôlé nont pas été meilleures comparativement aux pintades du milieu rural, bien que les aliments utilisés en milieu contrôlé aient été conformes aux normes de la littérature. Létude des performances de reproduction dans le milieu rural et en milieu contrôlé situe lâge des femelles à la première ponte entre 7 et 9 mois avec un poids moyen de 1220 ± 97 g. Les pontes sont hivernales et les couvées sont réalisées dans 95,5 % des cas par les poules avec un nombre moyen de 14 ± 4 ufs incubés par poule et un taux global déclosion de 70 % pour une durée moyenne dincubation de 26 jours. La chute de la probabilité de survie a été la plus importante durant les 50 premiers jours de vie au cours desquels un taux de mortalité de près de 50 % a été observé. Malgré donc son importance économique, nutritionnelle et sociale, lélevage traditionnel de pintade au Bénin reste peu productif en raison de nombreuses contraintes incluant une forte mortalité juvénile, diverses pathologies, la prédation, le climat, le logement et une alimentation inadéquate.
La troisième partie fait linventaire du régime alimentaire des animaux divaguant, par analyse du contenu de jabot. Elle a ainsi permis de préciser la composition de la ration journalière de ces animaux, y compris la complémentation reçue par les éleveurs afin doptimiser la production. Les ingrédients trouvés dans les jabots ont été identifiés et regroupés en six catégories principales à savoir : la supplémentation, les graines des végétaux de parcours, leurs feuilles, les produits animaux, les minéraux et les éléments non identifiés. La quantité et la proportion des suppléments et des graines des végétaux nétaient pas significativement différentes entre les saisons tandis que celles des feuilles de végétaux, des produits animaux et des minéraux étaient plus élevées au cours de la saison des pluies. Les suppléments, en occurrence le maïs et le sorgho, étaient les composants majoritaires au cours des deux saisons. Les graines de végétaux les plus consommés provenaient de Panicum maximum (saison des pluies) et de Rottboellia cochinchinensis (saison sèche). Les teneurs des contenus de jabot en matière organique, extractif non azoté, et en énergie métabolisable étaient plus élevées en saison sèche, par contre les concentrations des minéraux étaient plus élevées en saison pluvieuse. Aucune différence na été notée entre les deux saisons en termes de matière sèche, protéines brutes et en fibres brutes. Lidentification et la quantification des différents composants alimentaires, ainsi que la détermination de la composition chimique et de la valeur alimentaire des aliments ingérés par les pintades au cours de la divagation a mis en évidence des déficits structurels mais également conjoncturels liés aux variations saisonnières de la qualité, de la disponibilité ou de laccessibilité des aliments pendant certaines périodes de lannée. Des corrections adéquates pour améliorer la production de la pintade en milieu villageois ont ainsi pu être proposées. Les graines de mucuna, en raison de leur composition nutritive, ont été proposées comme élément de solution à ce problème.
La quatrième étude a été réalisée afin dévaluer leffet de deux traitements de base (chaleur humide et chaleur sèche) sur la teneur des facteurs anti-nutritionnels, la composition chimique et la digestibilité des graines de mucuna. Les traitements thermiques ont amélioré les teneurs en protéines tandis que les taux de fibres brutes ont été réduits. Les teneurs en L-dopa, principal élément toxique de la graine de mucuna, ont augmenté en fonction du taux dincorporation de la graine. Une réduction significative de 52 % du taux de la L-Dopa a été constatée dans les graines bouillies par rapport à celles qui ont été toastées. Le traitement thermique a influencé significativement la digestibilité des nutriments, excepté celle de la matière grasse. Il en a été conclu que les graines de mucuna traitées adéquatement peuvent être utilisées pour nourrir la pintade.
La cinquième étude a porté sur lutilisation des graines de mucuna et des feuilles et cossettes de manioc sur les performances de croissance et la qualité de la viande des pintades. Des effets dépressifs sur la croissance des pintades et une réduction drastique de la consommation alimentaire ont été notés dans les groupes recevant des graines de mucuna crues. Le poids moyen de la carcasse ainsi que les différents morceaux de la découpe ont été significativement plus faibles que dans le groupe témoin. Cependant, la production de viande a été similaire entre les groupes témoin et ceux ayant reçu la graine de mucuna bouillie. Une augmentation significative du poids du gésier a été observée dans les lots ayant reçu les aliments contenant le mucuna traité, ainsi quune réduction du poids moyen des foies des animaux recevant des graine de mucuna crues. Lincorporation des graines dans la ration na toutefois pas modifié la qualité de la viande, les valeurs de pH et de capacité de rétention deau ayant été similaires dans les 3 groupes. Les analyses des foies, des reins et des muscles nont pas révélé la présence de L-dopa.
Par ailleurs, les performances enregistrées chez des animaux recevant des feuilles et cossettes de manioc ont été significativement plus faibles par rapport à celles observées dans le groupe témoin. Toutefois, aucune différence significative na été observée au niveau du poids des différents morceaux (blancs, ensemble cuisses-pilons, ailes) et du rendement de la carcasse, en fonction du lot. Aussi, la substitution du grain de maïs par les feuilles et les cossettes de manioc a permis de réduire le coût de production de la pintade. Ces ingrédients constituent aussi une opportunité pour réduire la concurrence entre lhomme et la volaille pour la consommation de maïs.
En conclusion, cette étude a montré quil est possible dutiliser avec succès certaines ressources non-conventionnelles telles que le mucuna qui constitue une opportunité pour les pays pauvres et qui pourrait contribuer à lamélioration de lautosuffisance alimentaire à partir de ressources locales/This study suggests ways of improvement of local guinea fowl feeding by unconventional resources in Benin.
The first part of this work reviews the use of unconventional feed resources, and particularly Mucuna spp. seeds, in poultry diets. This review focuses on the context of their use, their nutritional values as well as the constraints that hamper their upgrading before assessing the effects of various treatments on toxins levels and on chemical composition.
The second part of this study concerns the village poultry production systems, when compared to improved poultry production in station. In Benin, as in most of the countries in the South of Sahara, the village poultry production is characterized by an extensive system, in which birds have to scavenge to find most of their feed. They live in cramped houses and dont benefit either from disease prevention programs or from adapted feeding systems. However, farmers provide cereal grains or some unconventional resources. In these conditions, guinea fowl weight at six months was 1121 ± 100 g. In improved rearing, i.e. where animals were bred in houses, received complete diet, were separated by sex and received veterinary care, the mean weights at the same age were 1151±108 g for males versus 1085 ± 74 g for females. In village chickens, birds that received vermifuge treatments were significantly heavier when compared to untreated ones (1221 ± 107 vs 1007 ± 31 g). Growth performances in improved conditions were similar to that obtained with the guinea fowls reared in village, although they received complete diets that were in accordance with guinea fowl requirements. In rural area and in station, the study on reproductive performance indicated the onset of the first laying between 7 and 9 months of age with a mean weight of 1220 ± 97 g. Eggs laying occurred in rainy season, and broods were performed at 95.5 % level by hens, the mean number of eggs brooded by hen being 14 ± 4, with 70% hatching rate for 26 days of incubation duration. The decrease of cumulative survival probability was marked during the first 50 days of live during which a mortality rate of about 50 % was observed. In spite of its economic, nutritional and social importance, guinea fowl productivity in village area in Benin remains weak because of numerous constraints including keet mortality, diseases, predation, climate, housing and low feed supply.
The third part of the work studies scavenging guinea fowls crop contents, i.e., ingredients naturally found by the animals on the ground and supplement offered by the farmers. Ingredients found in crops were identified and divided in six main categories including supplemental feed, seeds, green forages, animal materials, minerals and unidentified material. Amounts and proportions of supplemental feed and seeds were not significantly different between seasons, whereas those of green forage, animal materials and mineral matter were higher in rainy season. Supplemental feed, especially maize and sorghum, was the largest component of the crop content in both seasons. The most represented grass seeds were Panicum maximum (rainy season) and Rottboellia cochinchinensis (dry season). Dietary concentrations of organic matter, non-nitrogen extract and metabolisable energy were higher in the dry season, while mineral concentrations were higher in the rainy season. There were no significant differences between the two seasons in dry matter, crude protein or crude fibre. The identification and quantification of various feed ingredients, as well as the determination of chemical composition and nutritive value of ingredients ingested by scavenging guinea fowl allowed highlighting the structural and short-term deficiencies due to seasonal variations of diets quality and availability during the year. Adequate corrections to improve guinea fowl production in village area were so able to be proposed. Mucuna seeds could solve this problem because of its leguminous-type feed value.
The fourth study was carried out to evaluate the effects of two basic treatments (cooking and toasting) on anti-nutrients factor contents, chemical composition and digestibility of mucuna seeds. Heat treatments improved proteins content whereas that of crude fibre was reduced. Contents of L-dopa, the main anti-nutritional factor in mucuna seeds, increased according to seed level incorporation. L-dopa content was significantly reduced by 52 % in cooked seeds while toasting had no effect. Heat treatment improved significantly seed nutrients digestibility excepted that of the ether extract. It was concluded that when mucuna seed is adequately treated, it could be used in guinea fowl diet.
The fifth study concerned the effects of mucuna seeds and cassava leafs and cossets on guinea fowl growth and meat quality. Crude mucuna seeds had depressive effects on guinea fowl growth and feed intake. Mean carcass and cut-parts weights were significantly lower in control group. However, meat yield was similar between control and cooked seeds groups. The gizzard weights were significantly increased in processed seeds diets groups and liver weight reduction was noticed in birds fed on raw Mucuna seed. Mucuna seed did not alter meat quality as assessed by the pH and water holding capacity measurements. L-Dopa analyses in liver, kidneys and breast muscle did not reveal the presence of any tissue residues.
Furthermore, growth performances recorded in birds receiving cassava leaves and cossets were significantly lower when compared to the control group. However, no difference was observed in cut-parts (breasts, thigh-drumsticks, wings) and in carcass yield between groups. So, maize substitution by cassava leaves and cossets allowed reducing feed cost. It can be then suggested that those feeds allow reducing competition for maize consumption between human and poultry.
In conclusion, it is possible to successfully use unconventional feed resources such as mucuna seeds which are an opportunity for developing country and could contribute to improve food security with local resources.
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Stretched Exponential Decline Model as a Probabilistic and Deterministic Tool for Production Forecasting and Reserve Estimation in Oil and Gas ShalesAkbarnejad Nesheli, Babak 2012 May 1900 (has links)
Today everyone seems to agree that ultra-low permeability and shale reservoirs have become the potentials to transform North America's oil and gas industry to a new phase.
Unfortunately, transient flow is of long duration (perhaps life of the well) in ultra-low permeability reservoirs, and traditional decline curve analysis (DCA) models can lead to significantly over-optimistic production forecasts without additional safeguards.
Stretched Exponential decline model (SEDM) gives considerably more stabilized production forecast than traditional DCA models and in this work it is shown that it produces unchanging EUR forecasts after only two-three years of production data are available in selected reservoirs, notably the Barnett Shale.
For an individual well, the SEDM model parameters, can be determined by the method of least squares in various ways, but the inherent nonlinear character of the least squares problem cannot be bypassed. To assure a unique solution to the parameter estimation problem, this work suggests a physics-based regularization approach, based on critical velocity concept. Applied to selected Barnett Shale gas wells, the suggested method leads to reliable and consistent EURs.
To further understand the interaction of the different fracture properties on reservoir response and production decline curve behavior, a series of Discrete Fracture Network (DFN) simulations were performed. Results show that at least a 3-layer model is required to reproduce the decline behavior as captured in the published SEDM parameters for Barnett Shale. Further, DFN modeling implies a large number of parameters like fracture density and fracture length are in such a way that their effect can be compensated by the other one. The results of DFN modeling of several Barnett Shale horizontal wells, with numerous fracture stages, showed a very good agreement with the estimated SEDM model for the same wells.
Estimation of P90 reserves that meet SEC criteria is required by law for all companies that raise capital in the United States. Estimation of P50 and P10 reserves that meet SPE/WPC/AAPG/SPEE Petroleum Resources Management System (PRMS) criteria is important for internal resource inventories for most companies. In this work a systematic methodology was developed to quantify the range of uncertainty in production forecast using SEDM. This methodology can be used as a probabilistic tool to quantify P90, P50, and P10 reserves and hence might provide one possible way to satisfy the various legal and technical-society-suggested criteria.
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