Thick Targets
Mostrando 1-8 de 8 artigos, teses e dissertações.
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1. Patina Study and Characterization on Copper and Bronze with PIXE and ED-XRF Techniques. / Estudo e caracterização de pátinas em cobre e bronze com técnicas PIXE e ED-XRF
No acervo que compõem o patrimônio cultural, há muitos utensílios, obras de arte, monumentos, etc., que são feitos de metais. Mas dentre os diversos metais existentes, o cobre possui uma posição de destaque na história, pois este foi o primeiro utilizado pela humanidade. Os metais quando expostos à atmosfera podem sofrer processos de corrosão, o qu
Publicado em: 2010
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2. Medida de uma curva contínua do poder de freamento de partículas alfa em Al na região do pico de Bragg / Mensure of the stopping power continuous curve for alpha particles in Al foils around the Bragg peak energy
We present in this work experimental energy loss curves for alpha particles in Al foils around the Bragg peak energy. Our method is based on an integration of the energy spectrum, combining elastic scattering in thick targets with transmission method, providing an almost continuous energy loss curve with $2-3\%$ precision. To achieve this precision we perfor
Publicado em: 2008
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3. SR-TXRF detection limit reduction using thin polymer film substrates
Three different substrates for the analysis of liquid samples by Total Reflection X-Ray Fluorescence with Synchrotron Radiation (SR-TXRF) were investigated and compared: Lucite (Perspex), Kimfoil and Mylar. Dry targets were prepared by pipetting 5 mul aliquotes of the liquid samples (synthetic standards and fresh water samples) on the different substrates. A
Brazilian Journal of Physics. Publicado em: 2004-09
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4. Visual assessment of infants: vernier targets for the Catford drum.
Targets comprising a horizontal black line 5' thick offset by 1' were printed on strips to stick to the drums of the Catford Visual Acuity Apparatus. The 'vernier' targets so produced corresponded to the different sizes of Snellen letters from 6/6 to 2/60 when presented at 50 cm. Twenty-five children between the ages of 3 and 12 years with known amblyopia (m
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5. Oblique section 3-D reconstruction of relaxed insect flight muscle reveals the cross-bridge lattice in helical registration.
In this work we examined the arrangement of cross-bridges on the surface of myosin filaments in the A-band of Lethocerus flight muscle. Muscle fibers were fixed using the tannic-acid-uranyl-acetate, ("TAURAC") procedure. This new procedure provides remarkably good preservation of native features in relaxed insect flight muscle. We computed 3-D reconstruction
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6. Segregation and convergence of specialised pathways in macaque monkey visual cortex.
At the level of cortical area V2, the various visual inputs to the cortex have reorganised to form 3 distinct channels. Anatomically these are embodied in the thick and thin dark stripes, and paler interstripes characteristic of cytochrome oxidase architecture. Do the outputs of these compartments remain segregated at higher levels of processing, or are they
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7. Growth and differentiation of cerebellar suspensions transplanted into the adult cerebellum of mice with heredodegenerative ataxia.
Cell suspensions from cerebellar primordia of 12-day mouse embryos were grafted into the cerebellum of 4-month-old Purkinje cell degeneration (pcd) mutant mice and examined 2-3 months later. In contrast to those of nontreated mutants, all of the grafted cerebella exhibited Purkinje cells that had migrated into the molecular layer, where they were clustered o
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8. Semaphorin 3F, a chemorepulsant for endothelial cells, induces a poorly vascularized, encapsulated, nonmetastatic tumor phenotype
Melanoma is the most lethal skin cancer. Most deaths from melanoma result from metastases. Semaphorins have been shown to inhibit neuronal and endothelial cell migration, but the effects of semaphorins on tumor metastasis have not been documented. We found that semaphorin 3F (SEMA3F) was markedly downregulated in highly metastatic human cell lines in vitro a
American Society for Clinical Investigation.