ABSTRACT The vicuña is an emblematic species of fauna conservation in Peru. The vicuña population recovered after several years of timely measures for their conservation, moving to appendix II of CITES. Currently there are vicuñas that are kept free (silvestry) and populations kept enclosed in permanent fences (captivity). During 2018, 58 programmed captures (known as Chacus) were done in the Cusco Region, capturing 6777 animals, corresponding to 3229 and 3548 heads for silvestry and captivity, respectively. The age distribution in the case of juveniles was higher in silvestry (18.08%) with respect to the captivity system (7.2%), which would be evidence of the existence of higher mortality in this population. The 2012 national census indicated a higher proportion of female vicuñas in the general population of the Cusco Region; however, in this work similar populations were found by sex in both rearing systems. The proportion of vicuñas sheared with respect to those captured was 52.95 and 30.21% for silvestry and captivity, respectively, while fibre production was 172.4 and 156.7 g per animal on average for silvestry and captivity, respectively. These results lead to the possibility of rethinking the use of permanent fences in the breeding of vicuñas in captivity to produce fibre, considering the lower productive levels obtained in this management system.

RESUMEN La vicuña es una especie emblemática de la conservación de fauna en el Perú. La población de vicuñas se recuperó después de varios años de medidas oportunas para su conservación, pasando al apéndice II del CITES. En la actualidad existen vicuñas que se mantienen libres (silvestría) y poblaciones mantenidas encerradas en cercos permanentes (cautiverio). Durante 2018 se realizaron 58 capturas programadas (llamadas Chacus) en la Región Cusco, capturando 6777 animales, correspondiendo 3229 y 3548 cabezas para silvestría y cautividad, respectivamente. La distribución etaria en el caso de juveniles fue mayor en silvestría (18.08%) con respecto al sistema de cautividad (7.2%), lo cual estaría evidenciando la existencia de mayor mortalidad en esta población. El censo nacional de 2012 indica una mayor proporción de hembras en la población general de la Región Cusco; sin embargo, en este trabajo se encontraron poblaciones similares por sexo en ambos sistemas de crianza. La proporción de vicuñas esquiladas respecto a las capturadas fue de 52.95 y 30.21% para silvestría y cautividad, respectivamente, en tanto que la producción de fibra fue de 172.4 y 156.7 g por animal en promedio para silvestría y cautividad, respectivamente. Estos resultados conllevan a la posibilidad de replantear el uso de cercos permanentes en la crianza de vicuñas en cautiverio para la producción de fibra, considerando los menores niveles productivos obtenidos en este sistema de manejo.

Foram moídas duas séries de vidros silicatos para a obtenção de partículas com dimensões nas faixas micrométrica, submicrométrica e nanométrica, utilizando três tipos distintos de processos de moagem: moagem em moinho de esferas, em atritor, e de alta energia. Foram investigados os efeitos do tempo e do tipo do meio de moagem no tamanho de partícula, em suspensões aquosas e em isopropanol. Foram utilizados um granulômetro com o princípio de difração de laser e um microscópio eletrônico de varredura para a determinação do tamanho de partícula. A distribuição de tamanho de partículas com o menor tamanho médio de partícula igual a 0,3 µm foi obtida para vidros submetidos ao processo de cominuição em duas etapas, utilizando um moinho de alta energia.

Two series of silicate glasses were processed to micron-size, sub-micron size, and nanoparticles using three different milling systems: ball milling, attrition, and high-energy milling. The effect of milling time and media size on particle size and contamination were investigated in aqueous and isopropanol suspensions. The particle size was determined using a laser-diffraction particle size analyzer and scanning electron microscopy. The smallest glass particles with a median particle size of 0.3 µm were achieved by a two-step comminution process in a high energy mill.

Metas para pesquisas em andamento e futuras em nosso laboratório incluem o estudo de ataque químico em refratários em contacto com vidro, bem como os refratários da abóbada de tanques de fusão de vidro sob condições de queima gas/ar ou óleo/oxigênio. Ênfase em avaliação e caracterização de parâmetros críticos serão considerados em refratários comerciais, tais como microestrutura, porosidade e propriedades mecânicas. Um segundo foco é a avaliação do desempenho de refratários alternativos às abóbodas tradicionais e refratários de superestruturas, incluindo seus aspectos físicos, desenho de abóboda e qualidade de juntas.

Current and future research goals in our laboratories include the study of the attack of glass-contact refractories and of crown refractories in glass tank melters, under either air-gas or oxyfuel conditions. There is an emphasis on evaluation and characterization of critical parameters of commercial refractories such as microstructure, porosity and mechanical properties. A second focus is the evaluation of the performance of refractory alternatives to traditional crown and superstructure refractories including their physical aspects, crown design, and joint quality.

The degradation of refractories used in the construction of glass melting furnaces, whether caused by the action of molten glass, vaporized melt constituents, products of fuel combustion, or by batch dusts and vapors, can normally only be assessed after a campaign when the furnace is partially or completely disassembled. Corrosion tests to predict degradation usually employs small specimens exposed to accelerated working conditions which might not be simulative. The current testing procedures are discussed in terms of advantages/disadvantages. Three different tests seem to be needed to simulate the critical processes occurring in glass tank melters: flux-line corrosion, throat corrosion and crown corrosion. A pilot-size laboratory testing facility is being built for simulating corrosion attack under different conditions.