Application of amorphous carbon based materials as antireflective coatings on crystalline silicon solar cells

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)We report on the investigation of the potential application of different forms of amorphous carbon (a-C and a-C:H) as an antireflective coating for crystalline silicon solar cells. Polymeric-like carbon (PLC) and hydrogenated diamond-like carbon films were deposited by plasma enhanced chemical vapor deposition. Tetrahedral amorphous carbon (ta-C) was deposited by the filtered cathodic vacuum arc technique. Those three different amorphous carbon structures were individually applied as single antireflective coatings on conventional (polished and texturized) p-n junction crystalline silicon solar cells. Due to their optical properties, good results were also obtained for double-layer antireflective coatings based on PLC or ta-C films combined with different materials. The results are compared with a conventional tin dioxide (SnO(2)) single-layer antireflective coating and zinc sulfide/magnesium fluoride (ZnS/MgF(2)) double-layer antireflective coatings. An increase of 23.7% in the short-circuit current density, J(sc), was obtained using PLC as an antireflective coating and 31.7% was achieved using a double-layer of PLC with a layer of magnesium fluoride (MgF(2)). An additional increase of 10.8% was obtained in texturized silicon, representing a total increase (texturization + double-layer) of about 40% in the short-circuit current density. The potential use of these materials are critically addressed considering their refractive index, optical bandgap, absorption coefficient, hardness, chemical inertness, and mechanical stability. (C) 2011 American Institute of Physics. [doi:10.1063/1.3622515]1104Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Brazilian financial research agency MCTConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Treatment Patterns and Use of Resources in Patients With Tuberous Sclerosis Complex: Insights From the TOSCA Registry

Tuberous Sclerosis Complex (TSC) is a rare autosomal-dominant disorder caused by mutations in the TSC1 or TSC2 genes. Patients with TSC may suffer from a wide range of clinical manifestations; however, the burden of TSC and its impact on healthcare resources needed for its management remain unknown. Besides, the use of resources might vary across countries depending on the country-specific clinical practice. The aim of this paper is to describe the use of TSC-related resources and treatment patterns within the TOSCA registry. A total of 2,214 patients with TSC from 31 countries were enrolled and had a follow-up of up to 5 years. A search was conducted to identify the variables containing both medical and non-medical resource use information within TOSCA. This search was performed both at the level of the core project as well as at the level of the research projects on epilepsy, subependymal giant cell astrocytoma (SEGA), lymphangioleiomyomatosis (LAM), and renal angiomyolipoma (rAML) taking into account the timepoints of the study, age groups, and countries. Data from the quality of life (QoL) research project were analyzed by type of visit and age at enrollment. Treatments varied greatly depending on the clinical manifestation, timepoint in the study, and age groups. GAB Aergics were the most prescribed drugs for epilepsy, and mTOR inhibitors are dramatically replacing surgery in patients with SEGA, despite current recommendations proposing both treatment options. mTOR inhibitors are also becoming common treatments in rAML and LAM patients. Forty-two out of the 143 patients (29.4%) who participated in the QoL research project reported inpatient stays over the last year. Data from non-medical resource use showed the critical impact of TSC on job status and capacity. Disability allowances were more common in children than adults (51.1% vs 38.2%). Psychological counseling, social services and social worker services were needed by <15% of the patients, regardless of age. The long-term nature, together with the variability in its clinical manifestations, makes TSC a complex and resource-demanding disease. The present study shows a comprehensive picture of the resource use implications of TSC

Clinical Characteristics of Subependymal Giant Cell Astrocytoma in Tuberous Sclerosis Complex

BACKGROUND: This study evaluated the characteristics of subependymal giant cell astrocytoma (SEGA) in patients with tuberous sclerosis complex (TSC) entered into the TuberOus SClerosis registry to increase disease Awareness (TOSCA). METHODS: The study was conducted at 170 sites across 31 countries. Data from patients of any age with a documented clinical visit for TSC in the 12 months preceding enrollment or those newly diagnosed with TSC were entered. RESULTS: SEGA were reported in 554 of 2,216 patients (25%). Median age at diagnosis of SEGA was 8 years (range, 18 years. SEGA were symptomatic in 42.1% of patients. Symptoms included increased seizure frequency (15.8%), behavioural disturbance (11.9%), and regression/loss of cognitive skills (9.9%), in addition to those typically associated with increased intracranial pressure. SEGA were significantly more frequent in patients with TSC2 compared to TSC1 variants (33.7 vs. 13.2 %, p < 0.0001). Main treatment modalities included surgery (59.6%) and mammalian target of rapamycin (mTOR) inhibitors (49%). CONCLUSIONS: Although SEGA diagnosis and growth typically occurs during childhood, SEGA can occur and grow in both infants and adults

Newly Diagnosed and Growing Subependymal Giant Cell Astrocytoma in Adults With Tuberous Sclerosis Complex: Results From the International TOSCA Study

The onset and growth of subependymal giant cell astrocytoma (SEGA) in tuberous sclerosis complex (TSC) typically occurs in childhood. There is minimal information on SEGA evolution in adults with TSC. Of 2,211 patients enrolled in TOSCA, 220 of the 803 adults (27.4%) ever had a SEGA. Of 186 patients with SEGA still ongoing in adulthood, 153 (82.3%) remained asymptomatic, and 33 (17.7%) were reported to ever have developed symptoms related to SEGA growth. SEGA growth since the previous scan was reported in 39 of the 186 adults (21%) with ongoing SEGA. All but one patient with growing SEGA had mutations in TSC2. Fourteen adults (2.4%) were newly diagnosed with SEGA during follow-up, and majority had mutations in TSC2. Our findings suggest that surveillance for new or growing SEGA is warranted also in adulthood, particularly in patients with mutations in TSC2

SPECTRAL EVIDENCE FOR A DIRECTIONAL MOLECULAR ROTATION IN INTER-MOLECULAR HYDROGEN-BONDED LIQUIDS

64110811

THE SHAPE OF THE REFRACTIVE-INDEX VERSUS COMPOSITION CURVES FOR HYDROGEN-BONDED LIQUID-MIXTURES

73APR15916

Purification of metallurgical silicon by horizontal zone melting

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)In this study, we aimed at systematically determining the potential of the zone melting (ZM) technique to remove impurities from Metallurgical Grade Silicon (MG- Si) in an Electron Beam Furnace (EBF), using a water-cooled copper crucible. Our focus was on obtaining solar grade silicon, with the purity between Electronic Grade Silicon (EG-Si) and MG-Si, at lower cost than the silicon obtained by the Siemens process. The MG- Si (99.855% purity in mass, or 1,450 ppm of impurities) was processed by 1 and 2 passes of ZM at speed of 1 mm/min and 10 mm/min. The ZM process reduced in 98% the total amount of impurities present in the MG-Si, increasing the purity from 99% to 99.999%, an intermediate stage to achieve the electronic grade (> 99.9999%). Boron remained near the same after the ZM due to its vapor pressure be lower than the pressure of the furnace chamber and due its distribution coefficient in silicon be near the unit. Carbon and oxygen in the MG-Si were reduced from 106 to 35 ppm and from 30 ppm to 5 ppm, respectively, after ZM, and these values are very close to the levels in the electronic grade silicon. The electrical resistivity showed to be dependent on the boron concentration, but not on the phosphorus or the total amount of impurities. All ingots processed by ZM exhibited p-type characteristics, and it means that boron was really the dominant dopant. (C) 2011 Elsevier B.V. All rights reserved.98233239Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Determination of the effective distribution coefficient (K) for silicon impurities

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)For the production of photovoltaic cells, the silicon purity can be intermediate between metallurgical grade silicon (MG-Si, 98%-99.9% pure) and electronic grade silicon (>99.9999% pure). This silicon, with intermediate purity and that still meets solar cell requirements, is called upgraded metallurgical grade silicon (UMG-Si). One method of producing UMG-Si is applying a controlled solidification process, like unidirectional solidification (heat exchange method), zone melting (or zone refining), or Czochralski growth to MG-Si. These processes use the impurities solubility difference in solid and liquid silicon known as effective distribution coefficient (K). For these reasons, to study the solidification process, it is necessary to determine K for silicon impurities, which is the objective of this study. MG-Si (99.85% purity or 1500 ppm of impurities) was processed by 1 pass of zone melting at 1 mm/min using an electron beam furnace with water cooled copper crucible. The effective distribution coefficient (K) for impurities with Ko <= 10(-1) was found to follow the relation K = 0.03 Ko(-0.063). For boron, K = 0.8. Impurities with Ko between 10(-3) and 10(-8) presented similar effective distribution coefficients (K = 0.07 +/- 0.02), meaning that the effective distribution coefficient of a specific impurity depends on the total amount of impurities. The measured impurities profiles in silicon were compared with those obtained by Pfann's equations using the effective distribution coefficients and showed comparative results. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4739759]44Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Electronic and structural effects in muscular relaxants: Riparin I and Riparin III

Two muscular relaxants (MR), methyl ethers of N-benzoyl tyramine (Riparin 1) and N-(1,6-dihydroxybenzoyl) tyramine (Riparin 111) were studied with X-ray diffraction (XRD), optical spectroscopy and semi-empirical calculations. The XRD data show that the C=O group in Riparin I is 34 degrees out of plane from the closest benzene ring. The abinitio calculations using RHF/6-31G* suggest that the dihydroxybenzoyl (DHB) group in Riparin III forms intramolecular hydrogen bond between the H of the O-H group and the 0 of the C=O group, and gives a relatively planar structure between DHB group and C=O group. The spectral analysis together with the excitation energy calculations using the ZINDO program showed that the absorption band at 309 nm in Riparin III, absence in Riparin 1, is assigned to the pi-pi* transition associated mainly from the DHB. A long range charge-transfer (CT) transition, as the low-lying excited electronic state, S, has been calculated for both relaxants involving the non-bonding electron on carbonyl and/or amine group and the antibonding orbitals of aromatic ring. The planar structure of Riparin III and its extensive electron delocalization may have an important role on the pharmacological action mode and on the potency this MR as compared to those of Riparin I. (c) 2005 Elsevier B.V. All rights reserved.75341699132

Structural, surface, and thermomechanical properties of intrinsic and argon implanted tetrahedral amorphous carbon

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The structural, surface, and thermomechanical properties of intrinsic and argon incorporated tetrahedral amorphous carbon films deposited using the filtered cathodic vacuum arc process are reported. Argon atoms were simultaneously incorporated during the deposition of the films using an argon ion gun in the energy range of 0-180 eV. Contact angle measurements revealed that all of the deposited films are hydrophobic, regardless of the substrate bias voltage that was applied during the depositions. Thermal desorption spectroscopy measurements revealed that high argon bombarding energy favors films that are structurally more compact and thermally more stable. An investigation unbinding the mechanism of argon effusion and intrinsic stress relief is presented. (C) 2013 American Vacuum Society. [http://dx.doi.org/10.1116/1.4774326]312Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)INES/MCTFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FAPESP [10/51246-1, 2005/53926-1