Carbon Nanotube Doped Tellurite Glasses

In the past it was observed that buck ball doped glasses showed enhanced optical nonlinearities. However, carbon nanotubes are much more stable than buck ball and should be a better choice for that purpose. Therefore we decided to investigate the possibility to produce carbon nanotubes doped tellurite glasses and measured their optical nonlinearities. Tellurite glasses already have a larger nonlinearity compared to silica, and other, glasses. We produced TeO 2-ZnO tellurite family glasses doped with multi wall Carbon Nanotube (CNT). The CNTs acquired from Carbolex were vigorously mechanically mixed with the tellurite glass precursors and melted in platinum crucible around 650°C in a controlled atmosphere inside an electrical induction furnace. We used the lowest temperature possible and controlled atmosphere to avoid the CNT oxidation. The glass melt was cast in a stainless steel and thermally treated at 300°C for 5 hours to relieve internal stresses. The samples were than cutted and polished to perform the optical characterization. We measured refractive index and thermo physical properties, such as vitreous transition Tg, crystallization onset Tx and melting Tf temperatures. Raman spectroscopy showed the possible presence of CNTs.6890Iijima, S., (1991) Nature, 354, p. 56http://www.ati.surrey.ac.uk/news/n, onlinearDiMaio, J., Rhyne, S., Yang, Z., Fu, K., Czerw, R., Xu, J., Webster, S., Ballato, J., (2003) Information Sciences, 149, p. 69Aoki, Y., Okubo, S., Kataura, H., Nagasawa, H., Achiba, Y., (2005) Chem. Lett, 34 (4), p. 562Misra, S.K., Watts, P.C.P., Valappil, S.P., Silva, S.R.P., Roy, I., Boccaccini, A.R., (2007) Nanotechnology, 18, p. 07570

Use Of Cscl To Enhance The Glass Stability Range Of Tellurite Glasses For Er3+ Doped Optical Fiber Drawing

Tellurite glasses are important as a host of Er3+ ions because of their great solubility and because they present broader gain bandwidths than Er3+-doped silica, with promise to increase the bandwidth of communication systems. However, the small glass stability range (GSR) of tellurite glasses compromises the quality of the optical fibers. We show that the addition of CsCl to tellurite glasses can increase their GSR, making it easier to draw good quality optical fibers. CsCl acts as a network modifier in glass systems, weakening the network by forming Te-Cl bonds. We show that the thermal expansion coefficient mismatch is in the right direction for optical fiber fabrication purposes and that the Bi2O3 content can be used to control the refractive index of clad and core glasses. Single-mode and multi-mode Er3+-doped optical fibers were produced by the rod-in-tube method using highly homogeneous TeO2-ZnO-Li 2O-Bi2O3-CsCl glasses. Far infrared spectra of the glass samples exhibit absorption bands of the Te-Cl bond.6469Mori, A., Ohishi, Y., Sudo, S., Erbium-doped tellurite glass fibre laser and amplifier (1997) Electron. Lett, 33 (10), pp. 863-864Sekiya, T., Mochida, N., Ohtsuka, A., Tonokawa, M., Raman-spectra of Mo-TeO2 (M = Mg, Sr, Ba and Zn) glasses (1994) J. Non-Cryst. Solids, 168, pp. 1-2,106-114Bindra, K.S., Bookey, H.T., Kar, A.K., Wherrette, B.S., Liu, X., Jha, A., Nonlinear optical properties of chalcogenide glasses: Observation of multiphoton absorption (2001) Appl. Phys. Lett, 79 (13), pp. 1939-1941Wang, J.S., Vogel, E.M., Snitzer, E., Jackel, J.L., da Silva, V.L., Silbergerg, Y., 1.3 μm emission of neodymium and praseodymium in tellurite-based glasses (1994) J. Non-Cryst. Solids, 178, pp. 109-113Shen, S., Jha, A., Zhang, E., Wilson, S.J., Compositional effects and spectroscopy of rare earths (Er3+, Tm3+, and Nd 3+) in tellurite glasses (2002) C.R. Chim, 5 (12), pp. 921-938Yamada, M., Mori, A., Ono, H., Kobayashi, K., Kanamori, T., Ohishi, Y., Broadband and gain-flattened Er3+-doped tellurite fibre amplifier constructed using a gain equaliser (1998) Electron. Lett, 34 (4), pp. 370-371Mori, K., Kobayashi, M., Yamada, T., Kanamori, K., Oikawa, Y., Nishida, Y., Ohishi, Y., Low noise broadband tellurite-based Er3+-doped fibre amplifiers (1998) Electron. Lett, 34 (9), pp. 887-888Snitzer, E., Vogel, E.M., Wang, J.S., Tellurite glass and fiber amplifier (1993), US Patent 5,251,062Aitken, B.G., Ellison, A.J.G., Tellurite glasses and optical components (2001), US Patent 6,194,334Ding, Y., Jiang, S., Hwang, B.C., Luo, T., Peyghambarian, N., Himei, Y., Ito, T., Miura, Y., Spectral properties of erbium-doped lead halotellurite glasses for 1.5 μm broadband amplification (2000) Opt. Mater, 15 (2), pp. 123-130Keiser, G., (1999) Optical Fiber Communication, , Mac-Graw Hill, New YorkBarbosa, L.C., Cesar, C.L., Mazali, I.O., Barbosa, L.C., Alves, O.L., Spectroscopic and thermal properties of Ga2S 3-Na2S-CsCl glasses (2006) J. Am. Ceram. Soc, 89 (3), pp. 1037-1041Mazali, I.O., Barbosa, L.C., Alves, O.L., Preparation and characterization of new niobophosphate glasses in the Li2O-Nb 2O5-CaO-P2O5 system (2004) J. Mater. Sci, 39 (6), pp. 1987-1995El-Kheshen, A.A., Zawrah, M.F., Sinterability, microstructure and properties of glass/ceramic composite (2003) Ceram. Int, 29 (3), pp. 251-257A. Hruby, Evaluation of glass-forming tendency by means of DTA, Czech. J. Phys. B, B22 1187-& (1972)Burger, H., Vogel, W., Kozhukharov, V., IR transmission and properties of glasses in the TeO2-[RNOM, RNXM, RN(SO4)M, RN(PO3)M and B2O3] systems (1985) Infr. Phys, 25 (1-2), pp. 395-409Higazy, A.A., Bridge, B., Infrared-Spectra of the vitreous system CO 3O4-P2O5 and their interpretation (1985) Jour. Mat. Sci, 20 (7), pp. 2345-2358Bridge, B., Round, R., Computation of the bulk modulus of the high temperature ceramic superconductor YBa2Cu3O7-X from unit-cell data (1988) Jour. Mat. Sci. Lett, 7 (1), pp. 63-65Reynoso, V.C.S., Barbosa, L.C., Alves, O.L., Aranha, N., César, C.L., Preparation and characterization of heavy-metal oxide glasses - Bi2O3-PbO-B2O3-GeO 2 system (1994) J. Mater. Chem, 4 (4), pp. 529-532Canale, J.E., Condrate, R.A., Nassau, K., Cornilsen, B.C., Characterization of various glasses in the binary PbO-GeO2 and Bi2O3-GeO2 systems (1986) J. Can. Ceram. Soc, 55, pp. 50-56Adams, D.M., Lloyd, M.H., Far-Infrared reflectance spectra of some hexachlorotellurates and other hexachlorometallates (1971) Jour. Chem. Soc. A.-Inorganic Phys Theor, 7, p. 878Gloge, D., Weakly guiding fibers (1971) Appl. Opt, , 10 [10] 2252-

Grain and seed protein functionality

Editado por Jiménez-López, José Carlos (CSIC

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time, and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space. While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes, vast areas of the tropics remain understudied. In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity, but it remains among the least known forests in America and is often underrepresented in biodiversity databases. To worsen this situation, human-induced modifications may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge, it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Parâmetros genéticos para características de crescimento e reprodutivas em bovinos Nelore no Brasil

To know the genetic and phenotypic progress of a population is important to evaluate the outcome of the adopted selection programmes and as guiding elements of future actions. The objective was to estimate genetic parameters, genetic and phenotypic trends of weights at 205 (W205) 365 (W365) 550 (W550) days of age, age at first calving (AFC), scrotal circumference (SC) and calving interval (CI) of 175.231 Nellore, born in the period 1967-2011 in the Northeast region of Brazil. The components of (co) variance and breeding values were obtained by restricted maximum likeli-hood methodology. Estimates of heritability coefficients for growth traits were of a low to moderate magnitude. Direct selection will provide greater genetic gains for W550. For reproductive traits, the heritability estimate was low for ACF and close to zero for CI. However, for the SC heritability was moderate, indicating its use as selection criteria. Direct genetic trends for W205, W365, W550 and ACF indicate small genetic gains over the years. Phenotypic progress shows that the features are improving with the years, mainly because of environmental improvements.Conhecer o progresso genético e fenotípico de uma população é importante para se avaliar o resultado dos programas de seleção adotados e como elementos norteadores de ações futuras. Assim, objetivou-se estimar parâmetros genéticos, tendências genéticas e fenotípicas dos pesos aos 205 (P205), 365 (P365) e 550 (P550) dias de idade, idade ao primeiro parto (IPP), circunferência escrotal (CE) e intervalos de partos (IDP) de 175.231 bovinos Nelore, nascidos no período de 1967 a 2011 na região Nordeste do Brasil. Os componentes de (co) variância e valores genéticos foram obtidos por meio da metodologia da máxima verossimilhança restrita. As estimativas dos coeficientes de herdabilidades para as características de crescimento foram de baixa a moderada magnitude. A seleção direta proporcionará maiores ganhos genéticos para P550. Para as características reprodutivas, a estimativa de herdabilidade foi baixa para IPP e próxima a zero para IDP. Contudo, para a CE a herdabilidade foi moderada, indicando seu uso como critério de seleção. As tendências genéticas diretas para P205, P365, P550 e IPP, indicam pequenos ganhos genéticos ao longo dos anos. Os progressos fenotípicos evidenciam que as características estão melhorando com o decorrer dos anos, principalmente em decorrência da melhoria ambiental