All-fiber fast acousto-optic temporal control of tunable optical pulses

We demonstrate a new all-fiber electrically tunable modulation method which significantly reduces the response time of a Bragg grating acousto-optic modulator. A 4 cm long device is fabricated with a 1 cm grating inscribed in a suspended core fiber. An acoustic pulse train is switched out of phase along the fiber, damping unwanted natural resonant vibrations inside the grating. The device rise time is decreased from 56 to 9 µs by tuning the duty cycle of the driven electrical signal, contributing to achieve the shortest switching time of 15.6 µs. This tunable temporal response reveals unique features to change the profile of optical pulses. High pulse modulation depths are achieved employing a compact acousto-optic modulator, pointing to fast switching of all-fiber photonic devices

Zoneamento agroclimático de nogueira-macadâmia para o Brasil

A noz-de-macadâmia tem grande potencial de mercado, mas ainda é pouco explorada no Brasil. As condições de clima e solo de uma região têm grande influência na fenologia, qualidade, produtividade e sustentabilidade do cultivo. O objetivo deste trabalho foi realizar o zoneamento agroclimático da nogueira-macadâmia para o Brasil. Para tanto, foram utilizadas informações que relacionassem o desenvolvimento da planta e suas necessidades climáticas para estabelecimento de classes de aptidão e posterior mapeamento das regiões aptas, marginais e inaptas para o cultivo. Foram utilizados dados médios de 30 anos de temperatura do ar e precipitação mensal de 1.073 estações climatológicas no Brasil. Como resultado, observou-se que São Paulo, Rio de Janeiro, Espírito Santo, sul de Minas Gerais, leste de Mato Grosso do Sul e oeste do Paraná apresentam condições favoráveis para o cultivo de macadâmia

Risk profiles and one-year outcomes of patients with newly diagnosed atrial fibrillation in India: Insights from the GARFIELD-AF Registry.

BACKGROUND: The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective noninterventional registry, which is providing important information on the baseline characteristics, treatment patterns, and 1-year outcomes in patients with newly diagnosed non-valvular atrial fibrillation (NVAF). This report describes data from Indian patients recruited in this registry. METHODS AND RESULTS: A total of 52,014 patients with newly diagnosed AF were enrolled globally; of these, 1388 patients were recruited from 26 sites within India (2012-2016). In India, the mean age was 65.8 years at diagnosis of NVAF. Hypertension was the most prevalent risk factor for AF, present in 68.5% of patients from India and in 76.3% of patients globally (P < 0.001). Diabetes and coronary artery disease (CAD) were prevalent in 36.2% and 28.1% of patients as compared with global prevalence of 22.2% and 21.6%, respectively (P < 0.001 for both). Antiplatelet therapy was the most common antithrombotic treatment in India. With increasing stroke risk, however, patients were more likely to receive oral anticoagulant therapy [mainly vitamin K antagonist (VKA)], but average international normalized ratio (INR) was lower among Indian patients [median INR value 1.6 (interquartile range {IQR}: 1.3-2.3) versus 2.3 (IQR 1.8-2.8) (P < 0.001)]. Compared with other countries, patients from India had markedly higher rates of all-cause mortality [7.68 per 100 person-years (95% confidence interval 6.32-9.35) vs 4.34 (4.16-4.53), P < 0.0001], while rates of stroke/systemic embolism and major bleeding were lower after 1 year of follow-up. CONCLUSION: Compared to previously published registries from India, the GARFIELD-AF registry describes clinical profiles and outcomes in Indian patients with AF of a different etiology. The registry data show that compared to the rest of the world, Indian AF patients are younger in age and have more diabetes and CAD. Patients with a higher stroke risk are more likely to receive anticoagulation therapy with VKA but are underdosed compared with the global average in the GARFIELD-AF. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362

Thermal tunability of photonic bandgaps in photonic crystal fibers selectively filled with nematic liquid crystal

We address the bandgap effect and the thermo-optical response of high-index liquid crystal (LC) infiltrated in photonic crystal fibers (PCF) and in hybrid photonic crystal fibers (HPCF). The PCF and HPCF consist of solid-core microstructured optical fibers with hexagonal lattice of air-holes or holes filled with LC. The HPCF is built from the PCF design by changing its cladding microstructure only in a horizontal central line by including large holes filled with high-index material. The HPCF supports propagating optical modes by two physical effects: the modified total internal reflection (mTIR) and the photonic bandgap (PBG). Nevertheless conventional PCF propagates light by the mTIR effect if holes are filled with low refractive index material or by the bandgap effect if the microstructure of holes is filled with high refractive-index material. The presence of a line of holes with high-index LC determines that low-loss optical propagation only occurs on the bandgap condition. The considered nematic liquid crystal E7 is an anisotropic uniaxial media with large thermo-optic coefficient; consequently temperature changes cause remarkable shifts in the transmission spectrums allowing thermal tunability of the bandgaps. Photonic bandgap guidance and thermally induced changes in the transmission spectrum were numerically investigated by using a computational program based on the beam propagation method. © 2010 SPIE.Instituto de Estudos Avançados - IEAv, São José dos Campos-SP, 12228-001Instituto Tecnológico de Aeronáutica - ITA, São José dos Campos-SP, 12228-900Universidade Estadual Paulista Júlio de Mesquita Filho, Guaratinguetá-SP, 12516-410Universidade Estadual Paulista Júlio de Mesquita Filho, Guaratinguetá-SP, 12516-41

Macrobending SMS fiber-optic anemometer and flow sensor

CNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIORWe report a simple, high sensitivity, good resolution and low-cost fiber-optic anemometer and flow sensor based on reflective single mode-multimode-single mode structure bent by air flow. The dragging force on the multi-mode section causes it to bend resulting in multimodal interference (MMI) effects which are related to the fluid velocity and flow rate. Bending effects on the output power profile are investigated and numerical simulation combined with experimental data demonstrate that the output power intensity may increase or decrease with the rise of curvature, depending on MMI conditions and field deformation. The sensor behavior with air flow velocity is evaluated by spectral analysis using a variety of methods as wavelength shifting of a selected peak and output power intensity of selected wavelength and output power intensity of selected points. Experimental tests using air stream inside a wind tunnel provided a reliable dynamic range from 4 to 10 m/s. Peak sensitivities of 435.13 pm/(m/s) with resolution of 17.4x10(-3) m/s for wavelength shifting and 2.62 dB/(m/s) for output power intensity are obtained. These results assure that the sensor can be effectively used in a wide variety of applications, such as anemometer and flow rate meter.5219CNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIORCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIORSem informaçãoSem informaçã