<p> Orientations of deformation lamellae in quartz and C-axes of quartz grains containing lamellae were measured at seven locations across a gently folded bed of the Oriskany Sandstone, central Pennsylvania. Lamellae so measured have an average inclination of 20°-30° to the basal plane, and are therefore categorized as "subbasal".</p> <p> Fabrics of poles to deformation lamellae and corresponding C-axis orientations suggest a paleostress field for the fold which had the arrangement; σ1 bedding parallel, σ3 bedding perpendicular, and σ2 fold axis subparallel. Relative magnitudes of the stresses were given by the condition σ1 > σ3. σ2 is believed to have varied in magnitude between σ1 and σ3 during fold development.</p> <p> Exact timing of formation of lamellae is uncertain. Textural evidence shows that they predate a later generation of compressional and tensional microfractures associated with the deformation. The best explanation is that they formed in early stages of layer parallel compaction when compressive stresses in all zones of the fold were greatest. Stress refraction may or may not have been operative.</p> / Thesis / Bachelor of Science (BSc)

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Submitted by (edna.saturno@ufrpe.br) on 2016-12-14T15:53:11Z No. of bitstreams: 1 Alison Van Der Linden de Almeida.pdf: 1873549 bytes, checksum: d2a79be9c753493a5173b287d1cdc143 (MD5) / Made available in DSpace on 2016-12-14T15:53:11Z (GMT). No. of bitstreams: 1 Alison Van Der Linden de Almeida.pdf: 1873549 bytes, checksum: d2a79be9c753493a5173b287d1cdc143 (MD5) Previous issue date: 2014-07-08 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / In the meridional agreste of Pernambuco, the Regolithic Neosoil are used in various agricultural activities, which includes the production of beans. The productive potential of these soils may be different between the municipalities of occurrence due to the physicalhydric behavior exhibited by these soils, or the occurrence of lamellae in some areas, which may contribute to greater production. The objective of this study was to investigate the morphological, chemical and hydro-physical characteristics of Regolithic Neosoil located in the meridional agreste of Pernambuco in order to understand the behavior of water in these soils. Morphological, physical, chemical, water, mineralogical and micromorphological attributes of three profiles, being P1 (Caetés), P2 (Paranatama) and P3 (São João) were analyzed. Lamellae were found in horizons C1 and C2 of P3, which may be related to an increase in water retention profile. The morphological and chemical characteristics showed no differences to justify a differential productive bean between profiles. The micromorphology and hydric study showed that P3 has greater capacity to retain water, better distribution of pore diameters, and has a porosity and packaging material that promotes increased water retention than P1 and P2, mainly in C2 horizons and C4. The characteristics of P3 make this profile presents a higher yield potential than the profiles P1 and P2. / No Agreste Meridional de Pernambuco os Neossolos Regolíticos são utilizados em diversas atividades agrícolas, onde se destaca a produção de feijão. O potencial produtivo desses solos pode ser diferente entre os municípios de ocorrência em virtude do comportamento físico-hídrico apresentado por esses solos, ou pela ocorrência de lamelas em algumas áreas, que podem contribuir para uma maior produção. Objetivou-se no presente estudo analisar as características morfológicas, químicas e físico-hídricas de Neossolos Regolíticos localizados no Agreste Meridional de Pernambuco com a finalidade de se entender o comportamento da água nesses solos. Foram analisados os atributos morfológicos, físicos, químicos, hídricos, mineralógicos e micromorfológicos de três perfis, sendo P1 (Caetés), P2 (Paranatama) e P3 (São João). Foram encontradas lamelas nos horizontes C1 e C2 do P3, que podem estar ligadas a um aumento da retenção de água nesse perfil. Os atributos morfológicos e químicos não mostraram diferenças que justificassem um diferencial produtivo de feijão entre os perfis. O estudo hídrico e micromorfológico mostrou que o P3 apresenta maior capacidade de retenção de água, melhor distribuição dos diâmetros de poros, além de possuir uma porosidade e empacotamento do material que favorece uma maior retenção de água que os P1 e P2, principalmente nos horizontes C2 e C4. Essas características do P3 fazem com que esse perfil apresente um maior potencial produtivo que os perfis P1 e P2.

Yes / The structural formation and development of isotactic polypropylene (iPP) upon the micro-injection molding process was investigated at different mold temperatures and molecular weights utilizing a real-time synchrotron radiation small angle X-ray scattering (SAXS) technique combined with a customized micro-injection molding apparatus. Shish-kebab structure and parent-daughter lamellae were found to be formed during micro-injection molding for all iPP samples. In the case of kebab lamellae, a considerable growth in the long period and in the average thickness of lamellar crystallites and amorphous domains is observed at initial stages of crystallization for samples molded at varying temperatures. This effect is caused by the successive formation of thin lamellae in the outer layer and thick lamellae in the inner layer during the manufacturing process as evidenced by the spatial distribution of the crystalline lamellae across the thickness. In addition, the length of the shish formation increases remarkably at the onset of crystallization, the extent of which is dependent on the mold temperature. Despite the large changes of the lamellar stacks and the shish misorientation, the final length of the shish remains essentially unchanged when varying mold temperature. Since there is a critical orientation molecular weight above which the chains are stretched and oriented to form stable shish, the iPP sample with a low molar mass exhibits an overall decrease in the scattering intensity of SAXS patterns compared to the high molecular weight polypropylene. / This work is financially sponsored by the National Key R&D Program of China (2018YFB0704200), National Natural Science Foundation of China (21674119, 21790342 and 51525305), and Royal Society Newton Advanced Fellowship, United Kingdom (NA150222).

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The specific surface area reduction and pore size distribution coupled with N2 adsorption-desorption hysteresis isotherm were studied in the temperature range of 1400-1550¢J for periclase MgO powder having 0.1£gm in size and with face-centered cubic structure. The apparent activation energy of such a rapid coarsening-coalescence process for MgO powder was estimated as 181¡Ó3kJ/mol. The minimum temperature for sintering/coarsening/coalescence of submicron MgO particles was estimated to be near 1300¢J based on the extrapolation of steady specific surface area reduction rates to zero. Pulsed laser ablation (PLA) of periclase MgO powders in water was conducted under Q-switch mode and specified water height and water depth (10 mm) for an accumulation time of 5 and 20 minutes at 10 Hz. Such a PLA process has successfully synthesized nanosized and protonated MgO particles from Mg(OH)2 and lamellar precusors, implying the three phases may co-exist at high pressure and temperature conditions upon dynamic shock loading. A significant internal compressive stress up to 10 GPa was built up for the MgO but not the readily relaxed Mg(OH)2 nanocondensates. The lamellae-derived Mg(OH)2 tended to undergo a dehydroxylation process to become MgO following a specific crystallographic relationship, i.e. lamellar basal layer parallel to Mg(OH)2(0001) and MgO(111). The minimum band gap of the colloidal solution of MgO/Mg(OH)2/lamellae was lowered to ca. 5.2eV after the PLA process.

Submitted by Mario BC (mario@bc.ufrpe.br) on 2016-07-28T13:30:24Z No. of bitstreams: 1 Francis Henrique Tenorio Firmino.pdf: 4853310 bytes, checksum: 1fe150e845bd37deb7105c6799480a8b (MD5) / Made available in DSpace on 2016-07-28T13:30:24Z (GMT). No. of bitstreams: 1 Francis Henrique Tenorio Firmino.pdf: 4853310 bytes, checksum: 1fe150e845bd37deb7105c6799480a8b (MD5) Previous issue date: 2016-02-19 / The lamellae’s genesis in soils is related to geogenetics processes, pedogenetic or even pedogeogenetics. The presence and expression of this feature is important to crop production due to increased capacity and retention or reduction in evaporation of water from the soil. Even though the lamellae has common occurrence, little is known about its genesis in the Agreste of Pernambuco and how they vary in their properties (thickness, composition, distribution, etc.). Thus, the objective of this work is to identify and characterize the main mechanisms involved in the formation of lamellae along a litotoposequence in southern Pernambuco’s Agreste. For this we used collecting spots, with regular spacing between them, associated with an adaptation of the structural analysis of soil cover proposed by Boulet (1993), which provided an understanding of the distribution of horizons and lamellae along the slope. Augers were made to separate the segments within the litotoposequence, allowing allocation and collection of representative profiles to each segment. Morphological, chemical, physical, physical-hydric, sedimentological, mineralogical and micromorphological analysis were held in the profiles and in selected horizons. In general, it was observed that the formation of lamellae is pedogenetic, given the sieving clays promoted by more enclosed areas of fine sand grains resulting from the disintegration of quartz polycrystalline. The first formed lamellae were from the surface and the formation is controlled by the water flow. The thickness of the lamellae directly related to the spacing in the areas between lamellaes. Saturating Ca2+, Mg2+ and Al3+ bring upon the lamellae stability within the segments. The lamellae provide greater water retention and act as chemical filters, with high base saturation. The advance in depth is the result of moisture maintenance, and the aluminum saturation controls the non-development of new lamellae. The hillside has caulinitic domain, due to the good drainage of the soils. / A gênese de lamelas em solos está relacionada a processos geogenéticos, pedogenéticos, ou mesmo pedogeogenéticos. A presença e a expressividade dessa feição é importante para produção agrícola devido ao aumento da capacidade de retenção e, ou redução na evaporação da água do solo. Mesmo as lamelas tendo ocorrência comum, pouco se sabe sobre sua gênese no Agreste pernambucano e como elas variam em suas propriedades (espessura, composição, distribuição, etc.). Desta forma, o objetivo deste trabalho é identificar e caracterizar os principais mecanismos envolvidos na formação de lamelas ao longo de uma litotopossequência no Agreste meridional pernambucano. Para tanto foi utilizado pontos de amostragem com espaçamentos regulares, associados a uma adaptação da análise estrutural da cobertura pedológica proposta por Boulet (1993), que proporcionou o entendimento da distribuição dos horizontes e lamelas ao longo da vertente. Tradagens foram realizadas para separação dos segmentos dentro da litotopossequência, permitindo alocação e coleta dos perfis representativos a cada segmento. Análises morfológicas, químicas, físicas, físico-hídricas, sedimentológicas, mineralógicas e micromorfológicas foram realizadas nos perfis e em alguns horizontes selecionados. De forma geral, foram observados que a formação das lamelas é pedogenética, dado o peneiramento de argilas promovidos por zonas mais fechadas de grãos de areia finas oriundos da desintegração de quartzos policristalinos. As primeiras lamelas formadas foram as de superfície, e a formação é controlada pelo fluxo hídrico. A espessura das mesmas está diretamente relacionada com o espaçamento das zonas entre lamelas. A estabilidade das lamelas dentro dos segmentos é ocasionada pela saturação de Ca2+, Mg2+ e Al3+. As lamelas proporcionam uma maior retenção de água, e funcionam como filtros químicos, apresentando alta saturação por bases. O avanço em profundidade é consequência da manutenção da umidade, e a saturação por alumínio controla o não desenvolvimento de novas lamelas. A vertente apresenta domínio caulinítico, devido a boa drenagem desses solos.

Hybrid organic-inorganic materials represent a new class of materials having scientific and technological potential. In this thesis, Polyhedral Oligomeric Silsesquioxanes (POSS) are used as an inorganic building block which has been tethered to an organic polymer. POSS are silica precusors, having a well defined silsesquioxane cental core surrounded by an organic periphery which makes them compatible with monomers and possibly polymers. The objectives of this study are to (1) study the basic structures of POSS homopolymers, (2) to incorporate POSS building blocks by a bottomup approach into polymer chains and study the resulting morphologies, and (3) to study the thin film behavior of POSS block copolymers. PMA and styryl POSS homopolymers of different peripheries were synthesized by ATRP and mass spectrometry studies were carried out by MALDI-TOF and ESI. PMA POSS chains undergo a number of fragmentations while styrly POSS chains have a relatively robust backbone. Poly(ethylene-butylene-b-MAPOSS), AB type copolymers and poly(MAPOSS-b-styrene-b-MAPOSS), ABA type copolymers were synthesized by a combination of anionic and ATRP polymerization. Spheres, inverse cylinders, lamellar and crystalline lamellar morphologies were observed for the poly(ethylene-butylene-b- MAPOSS) copolymers. In the poly(MAPOSS-b-styrene-b-MAPOSS) copolymers, cylindrical, lamellar and perforated lamellar morphologies were obtained. Beyond the interaction parameter (χ), total degree of polymerization (N) and volume fraction (f), the conformational asymmetry (ε) also plays an important role in determining the morphology of these block copolymer. Crystallization of the POSS phase and better thermal properties were observed in the both block copolymers. Thin film studies of poly(MAPOSS-b-styrene-b-MAPOSS) copolymers showed that the microdomains can be oriented either parallel or perpendicular to the substrate depending upon the film thickness, morphology and relative volume fractions of the connecting blocks. By removal of the organic phase, ordered mesoporous low dielectric constant silica films were obtained. These hybrid block copolymers are a potential candidate for nanopatterning applications.

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No description available.