Cério: propriedades catalíticas, aplicações tecnológicas e ambientais

Cerium based-compounds have great importance in a wide range of technological applications, such as: fuel cell devices development; metallurgic processes, petroleum refining; glass and ceramic production. Recently, its catalytic properties have been also explored for environmental applications, especially those to prevent or to control atmospheric and water pollution. Subjects covered in this work include a brief description of the fundaments of cerium catalytic properties and some relevant technological applications. Special attention is given to its photocatalytic activity and its ability to degrade pollutants. Recent results and future prospect about these applications are also evaluated.

Chemical treatment of papaya seeds aiming at long-term storage and control of damping off

Damping off is a nursery disease of great economic importance in papaya and seed treatment may be an effective measure to control. The aim of this work was to evaluate the quality of papaya seeds treated with fungicides and stored under two environmental and packaging conditions. Additionally, the efficiency of fungicide treatments in the control of damping-off caused by Rhizoctonia solani was evaluated. Papaya seeds were treated with the fungicides Captan, Tolylfluanid and the mixture Tolylfluanid + Captan (all commercial wettable powder formulations). Seeds of the control group were not treated. The seeds were stored for nine months in two conditions: packed in aluminum coated paper and kept at 7 ± 1ºC and in permeable kraft paper and kept in non-controlled environment. At the beginning of the storage and every three months the seed quality (germination and vigor tests), emergence rate index, height, dry mass and damping of plants in pre and post-emergence (in contaminated substrate and mycelia-free substrate) were analyzed. Both storage conditions as well as the fungicide treatments preserved the germination and seed vigor. In the infested substrate, seedling emergence was favored by fungicides, but in post-emergence, fungicides alone did not control the damping off caused by R. solani. Symptoms of damping off were not observed in the clean substrate. The results showed that the fungicide treatments may be used to pretreat papaya seed for long-term storage and commercialization.

Silicon in plant disease control

All essential nutrients can affect the incidence and severity of plant diseases. Although silicon (Si) is not considered as an essential nutrient for plants, it stands out for its potential to decrease disease intensity in many crops. The mechanism of Si action in plant resistance is still unclear. Si deposition in plant cell walls raised the hypothesis of a possible physical barrier to pathogen penetration. However, the increased activity of phenolic compounds, polyphenol oxidases and peroxidases in plants treated with Si demonstrates the involvement of this element in the induction of plant defense responses. The studies examined in this review address the role of Si in disease control and the possible mechanisms involved in the mode of Si action in disease resistance in plants.

Postharvest biological control of brown rot in peaches after cold storage preceded by preharvest chemical control 1

ABSTRACT Pathogenic fungi cause skin darkening and peach quality depreciation in post harvest. Therefore, alternative techniques to chemical treatment are necessary in order to reduce risks to human health. The aim of this study was to evaluate the effect of the application of Trichoderma harzianum in association with different fungicides applied before harvest to 'Eldorado' peaches for brown rot control and other quality parameters during storage. The treatments consisted of five preharvest fungicide applications (control, captan, iprodione, iminoctadine and tebuconazole) associated with postharvest application of T. harzianum, after cold storage (with and without application), in three evaluation times (zero, two and four days at 20 °C), resulting in a 5x2x3 factorial design. The application of T. harzianum only brought benefits to the control of brown rot when combined with the fungicide captan, at zero day shelf life. After two days, there was a greater skin darkening in peaches treated with T. harzianum compared with peaches without the treatment, except for peaches treated with the fungicide iprodione and T. harzianum The application of T. harzianum during postharvest showed no benefits for the control of brown rot, however, the association with fungicides reduced the incidence of Rhizopus stolonifer during the shelf life.

Monitoração do ambiente externo: uma necessidade para as organizações tecnológicas

Vários sinais evidentes no mundo de hoje indicam que a organização moderna, funcionando na fronteira da tecnologia, não pode mais confiar em métodos intuitivos e não-sistemáticos de agrupar e analisar informação necessária para o gerenciamento estratégico de suas operações. Enquanto os padrões de sinais que levam a esta conclusão estão se tornando mais evidentes todos os dias, a resposta organizacional a este desafio ainda é altamente irregular e freqüentemente irracional. A grande maioria das organizações só pratica a forma não-estruturada de observação (Monitoração Panorámica Informal), para monitorar seu ambiente externo. A recente onda de atividades em empresas tecnológicas, institutos de P&D e órgãos governamentais, para melhor acompanhar as mudanças bruscas e rápidas em seu ambiente externo, é indicativa da crescente tendência de se praticarem formas mais sofisticadas de MA. O objetivo deste trabalho foi o de desenvolver a conceituação do processo de MA dentro do contexto de planejamento estratégico e indicar, com base em uma revisão da literatura e na experiência do autor, como esta atividade pode ser estruturada dentro da organização. Devido à ampla gama de variáveis organizacionais influenciando o desenvolvimento de um sistema de MA, apenas diretrizes gerais puderam ser apresentadas. Entretanto, espera-se que este material venha a ajudar organizações interessadas a entenderem as opções disponíveis e derivarem uma solução compatível com suas atividades e recursos.

A contribuição da área produtiva no processo de inovações tecnológicas

Não há dúvida de que as inovações tecnológicas estão entre as principais fontes de vantagens compe­titivas para uma quantidade crescente de empresas industriais. A primeira parte deste trabalho apresenta breves considerações sobre o processo de inovação tecnológica à medida que diferencia a inovação radical da incrementai, dois tipos diferentes porém complementares de inovações. Na segunda parte é fcita uma distinção conccitual entre duas abordagens para implementar inovações incrementais. Por último, discute-se o papel das atividades operacionais e das técnicas de gestão da produção no processo de inovação tecnológica, levando em considera­ção a nova abordagem relacionada com o movimento da qualidade total.