Perspectivas da bubalinocultura no Baixo Madeira no estado de Rondonia.

Estudo preliminar visando suprir deficiencia de carne e leite dos moradores das margens do Rio Madeira. Envolve aspectos relativos a bubalinocultura, operacoes que formam o sistema, producao de leite, instalacoes, comercializacao e sugestoes para o fomento da bubalinocultura.bitstream/item/55121/1/Circ.tecn-03-0001.pd

Characterization of microstructured multiwalled carbon nanotube/polydimethylsiloxane composites for piezoresistive sensing applications

Technological advancements in the field of flexible and printed electronics are creating a need for large-area sensors that can be embedded over different types of surfaces. Such sensors can be used to monitor physical signals over flexible, curved, or soft devices. Hence, it is herein proposed, a formulation to produce piezoresistive multiwalled carbon nanotube/polydimethylsiloxane (MWCNT/PDMS) composites with tunable electric properties for pressure sensing purposes. The composite is obtained through few manufacturing steps, avoiding the use of hazardous solvents. Different weight percentages of MWCNT dispersed in PDMS are evaluated and the results evidence that using 3.0 wt% of infill is sufficient to obtain highly sensitive sensors. To enhance the dispersion of the MWCNT and add microstructure to the composite, a system composed of a surfactant and foaming agent is used. Finally, pressure sensing units and arrays are printed and tested. The sensors present fast response, low hysteresis, repeatability, and a sensing range of 0–160 kPa. The composite is more sensitive to lower pressure and a maximum sensitivity of 8.0% kPa−1 is achieved for porous composites at pressure <10 kPa. Thanks to these characteristics, the sensors are successfully used in the development of a pressure sensing array and heartbeat sensor for proof of concept.This work has been supported by NORTE-06-3559-FSE-000018, integrated in the invitation NORTE-59-2018-41, aiming the Hiring of Highly Qualified Human Resources, co-financed by the Regional Operational Programme of the North 2020, thematic area of Competitiveness and Employment, through the European Social Fund (ESF), and by the scope of projects with references UIDB/05256/2020 and UIDP/05256/2020, financed by FCT—Fundação para a Ciência e Tecnologia, Portugal

Photocatalytic thin films coupled with polymeric microcapsules for the controlled-release of volatile agents upon solar activation

This work reports on the application of solar-activated photocatalytic thin films that allow the controlled-release of volatile agents (e.g., insecticides, repellents) from the interior of adsorbed polymeric microcapsules. In order to standardize the tests,a quantification of the inherent controlled-release of a particular volatile agent is determined by gas chromatography coupled to mass spectroscopy, so that an application can be offered to a wide range of supports from various industrial sectors, such as in textiles (clothing, curtains, mosquito nets). This technology takes advantage of the established photocatalytic property of titanium dioxide (TiO2) for the use as an active surface/site to promote the controlled-release of a specific vapor (volatile agentfrom within the aforementioned microcapsules.Portuguese FCT COMPETE scientific programs, with references NANO/NTec-CA/0046/2007 and PTDC/CTM-NAN/119979/201

Modeling stock markets' volatility using GARCH models with normal, Student's t and stable Paretian distributions

As GARCH models and stable Paretian distributions have been revisited in the recent past with the papers of Hansen and Lunde (J Appl Econom 20: 873–889, 2005) and Bidarkota and McCulloch (Quant Finance 4: 256–265, 2004), respectively, in this paper we discuss alternative conditional distributional models for the daily returns of the US, German and Portuguese main stock market indexes, considering ARMA-GARCH models driven by Normal, Student’s t and stable Paretian distributed innovations. We find that a GARCH model with stable Paretian innovations fits returns clearly better than the more popular Normal distribution and slightly better than the Student’s t distribution. However, the Student’s t outperforms the Normal and stable Paretian distributions when the out-of-sample density forecasts are considered.info:eu-repo/semantics/acceptedVersio

CRIOCIRURGIA NO TRATAMENTO DE CANCRO CUTÂNEO NÃO-MELANOMA PALPEBRAL E PERIOCULAR – ANÁLISE RETROSPETIVA DE 78 CASOS

Introduction: Cryosurgery is a safe and effective treatment modality for non-melanoma skin cancers of the eyelids and periocular area, with a reported 5-year overall cure rate above 95%. Aim: Retrospective characterization of patients with non-melanoma skin cancer of eyelids and periocular regions diagnosed and treated with cryosurgery at our Department, between 1988 and 2004. Material and Methods: Review of the clinical records and statistical analysis of the following variables: age, sex, occupation, skin type, tumour characteristics, treatment modalities, aesthetic and functional outcomes and follow-up. Results: We treated 78 primary malignant neoplasms, in 78 Caucasian patients, 30 men and 48 women with a mean age of 75.5 years. Seventy-six of the seventy-eight tumours (97.4%) were nodular basal cell carcinoma (BCCs) and two were (2.6%) squamous cell carcinomas. More than half of the tumours were loca- ted in the inner canthus. Fractional cryosurgery was used in 52 cases (66.7%), conventional cryosurgery in 17 (21.8%) and segmental cryosurgery in nine (11.5%). The mean follow-up was 5 years with two relapses observed. There were no functional complications and the cosmetic results were excellent. The overall cure rate was of 97.4%. Conclusions: Fractional cryosurgery was the most used procedure. We achieved excellent functional and aesthetic results and a 97% five-year cure rate.KEYWORDS – Eyelid neoplasms; Cryosurgery; Carcinoma, Basal cell; Carcinoma, Squamous cell; Skin neoplasms. Introdução: A criocirurgia é um método seguro e eficaz no tratamento do cancro cutâneo não-melanoma das pálpebras e áreas perioculares, com uma taxa de cura aos 5 anos superior a 95%. Objetivo: Caracterização retrospetiva dos casos de cancro cutâneo não-melanoma palpebrais e perioculares diagnosticados e tratados com a criocirurgia no nosso Serviço, entre 1988 e 2004. Material e Métodos: Revisão dos processos clínicos e análise esta- tística das seguintes variáveis: idade, sexo, profissão, fototipo, características do tumor, modalidades de tratamento, resultados estéticos e funcionais e seguimento. Resultados: Foram tratados 78 neoplasias malignas primárias, em 78 pacientes, sendo 30 homens e 48 mulheres, com idade média de 75,5 anos. Setenta e seis dos tumores (97,4%) eram carcinoma de basocelular e dois (2,6%) carcinomas espinocelular. Mais de metade dos tumores localizava-se no canto interno do olho. A Criocirurgia fracionada foi usada em 52 casos (66,7%), a criocirurgia convencional em 17 (21,8%) e a criocirurgia segmentada em nove (11,5%). A média de seguimento foi de 5 anos, tendo ocorrido com duas recidivas locais. Não houve complicações funcionais e os resultados estéticos foram excelentes. A taxa de cura global foi de 97,4%. Conclusões: A criocirurgia fracionada foi o procedimento mais utilizado. Obtivemos excelentes resultados estéticos e funcionais e uma taxa de cura aos 5 anos de 97% cinco anos. PALAVRAS-CHAVE – Neoplasias das pálpebras; Criocirurgia; Carcinoma basocelular; Carcinoma espinocelular.

Percolation in binary mixtures of linkers and particles: chaining {\it {vs}} branching

Equilibrium gels of colloidal particles can be realized through the introduction of a second species, a linker that mediates the bonds between the colloids. A gel forming binary mixture whose linkers can self-assemble into linear chains while still promoting the aggregation of particles is considered in this work. The particles are patchy particles with $f_C$ patches of type $C$ and the linkers are patchy particles with $2$ patches of type $A$ and $f_B$ patches of type B. The bonds between patches of type $A$ ($AA$ bonds) promote the formation of linear chains of linkers. Two different ways (model A and model B) of bonding the linkers to the particles - or inducing branching - are studied. In model A, there is a competition between chaining and branching, since the bonding between linkers and particles is done through $AC$ bonds only. In model B linkers aggregate to particles through bonds $BC$ only, making chaining and branching independent. The percolation behaviour of these two models is studied in detail, employing a generalized Flory-Stockmayer theory and Monte Carlo simulations. The self-assembly of linkers into chains reduces the fraction of particles needed for percolation to occur (models A and B) and induces percolation when the fraction of particles is high (model B). Percolation by heating and percolation loops in temperature composition diagrams are obtained when the formation of chains is energetically favourable, by increasing the entropic gain of branching (model A). Chaining and branching are found to follow a model dependent relation at percolation, which shows that, for the same composition, longer chains require less branching for percolation to occur