Intracavity intensity noise suppression in the inverse Compton scattering source BriXSinO exploiting carrier-envelope offset manipulation

We report on a technique that exploits the control of the carrier -envelope offset to suppress the frequency-to-intensity noise conversion in the locking of a mode-locking laser against a high-finesse optical enhancement resonator. A proper combination of the laser carrier-envelope offset and the resonator finesse allows the improvement of the signal-to-noise ratio of the optical intensity trapped into the optical resonator. In this paper, we show the application of this technique in the laser system of the inverse Compton scattering source BriXSinO, currently under development in Milan, Italy, demonstrating the possibility of achieving an intracavity intensity noise reduction of a factor of 20

Carrier-envelope offset frequency measurement by means of an external optical resonator

A general-purpose method based on the implementation of the asymmetric Pound-Drever-Hall (PDH) technique is proposed to measure the carrier-envelope offset (CEO) frequency of a mode-locked laser using an external optical cavity. By analyzing the synchronously demodulated signal of the spectrally filtered cavity reflection when the optical resonator is locked to the mode-locked laser, a discriminating signal depending on the relative frequency offset between the mode-locked and optical cavity comb-like spectra is obtained. For a given geometry and group delay dispersion (GDD) of the cavity parameters (i.e., a known cavity mode offset), this signal can be used to retrieve the laser CEO. This approach turns out to be advantageous in terms of setup complexity with respect to other well-known techniques that rely on non-linear frequency generation, such as f-2f interferometers. In addition, this method can be used to precisely determine the laser-cavity spectral coupling, which is an important topic in cavity-enhanced spectroscopy and non-linear optics applications. After the theoretical description of the generalized asymmetric PDH signal, an experimental validation of the proposed method is reported using an Er-doped fiber frequency comb source centered at 1,550 nm, with a repetition rate of 250 MHz, locked to a linear optical cavity with a 1 GHz free spectral range. The theoretical effect of the GDD is confirmed experimentally using different cavity configurations. Moreover, the comparison with the CEO frequency values measured using an f-2f interferometer demonstrates the feasibility of the proposed method

Design and Optimization of a Pneumatic Clamping System for Direct-Driven Rotary Tables

Modern direct-driven and high-speed rotary tables with torque motor are optimally suited for all handling and assembly applications that require the shortest indexing times and flexible positioning. The following paper is devoted to the study, the design, and the optimization of an innovative table clamping system (brake for accurate positioning) actuated by pneumatic energy, working at a maximum clamping pressure of 6 bar. The challenge for the aforementioned application is related to developing a solution able to provide a maximum tangential torque (with clamping actuated) in the range of thousands of Nm without leveraging the use of high-pressure hydraulic energy. The optimization of the proposed solution is based on the precise calculation of the stresses in order to perform a fatigue assessment and on the elastic deformation of the clamps in order to set the correct tolerances between the mating parts. Eventually, an experimental campaign is carried out in order to tune the numerical model, which is then used to validate the proposed design solution

Medicine expenses and obesity in Brazil: an analysis based on the household budget survey

Abstract\ud \ud Background\ud Obesity can be considered a global public health problem that affects virtually all countries worldwide and results in greater use of healthcare services and higher healthcare costs. We aimed to describe average monthly household medicine expenses according to source of funding, public or private, and to estimate the influence of the presence of obese residents in households on total medicine expenses.\ud \ud \ud Methods\ud This study was based on data from the 2008–2009 Brazilian Household Budget Survey, with a representative population sample of 55,970 households as study units. Information on nutritional status and medicines acquired and their cost in the past 30 days were analyzed. A two-part model was employed to assess the influence of obesity on medicine expenses, with monthly household medicine expenses per capita as outcome, presence of obese in the household as explanatory variable, and adjustment for confounding variables.\ud \ud \ud Results\ud Out-of-pocket expenses on medicines were always higher than the cost of medicines obtained through the public sector, and 32 % of households had at least one obese as resident. Monthly household expenses on medicines per capita in households with obese was US$ 20.40, 16 % higher than in households with no obese. An adjusted model confirmed that the presence of obese in the households increased medicine expenses.\ud \ud \ud Conclusion\ud Obesity is associated with additional medicine expenses, increasing the negative impact on household budgets and public expenditure.We are grateful to the the Fundação de Amparo à Pesquisa do Estado de\ud São Paulo (FAPESP) for the research grant (process number 2012/17977-4)\ud and to the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior\ud (CAPES) for the doctoral scholarship to DSC

Superconducting RFQs

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Intra-uterine treatment for infections in cows.

Edição dos resumos da 20ª Reunião Anual da Sociedade Brasileira de Tecnologia de Embriões, Araxá, 2006

Chirality scenario of the spin-glass ordering

Detailed account is given of the chirality scenario of experimental spin-glass transitions. In this scenario, the spin glass order of weakly anisotropic Heisenberg-like spin-glass magnets including canonical spin glasses are essentially chirality driven. Recent numerical and experimental results are discussed in conjunction with this scenario.Comment: Submitted to J. Phys. Soc. Japan "Special Issue on Frustration

Brixsino High-Flux Dual X-Ray and THz Radiation Source Based on Energy Recovery Linacs

We present the conceptual design of a compact light source named BriXSinO. BriXSinO was born as demonstrator of the Marix project, but it is also a dual high flux radiation source Inverse Compton Source (ICS) of X-ray and Free-Electron Laser of THz spectral range radiation conceived for medical applications and general applied research. The accelerator is a push-pull CW-SC Energy Recovery Linac (ERL) based on superconducting cavities technology and allows to sustain MW-class beam power with almost just one hundred kW active power dissipation/consumption. ICS line produces 33 keV monochromatic X-Rays via Compton scattering of the electron beam with a laser system in Fabry-Pérot cavity at a repetition rate of 100 MHz. The THz FEL oscillator is based on an undulator imbedded in optical cavity and generates THz wavelengths from 15 to 50 micron

Whey block freeze concentration aiming a functional fermented lactic beverage with the addition of probiotic and guabiroba pulp (Campomanesia xanthocarpa O. Berg), a native Brazilian fruit.

Abstract. The scientific importance involved in this study was the use of whey, a co-product of the cheese industry, and its performance during the freeze concentration process. Moreover, the best-concentrated whey from the freeze concentration process, about the total solids, proteins, and mineral contents, was used to prepare two functional fermented lactic beverages. Therefore, whey was subjected to the freeze concentration in blocks with gravitational thawing. Process performance indicated better yields and efficiency for the second stage of freeze concentration. Concentrated whey 2 was used to prepare two fermented lactic beverages added with probiotics: one without adding guabiroba pulp (control) and a beverage incorporated with 10% guabiroba pulp. Containing guabiroba pulp was not enough to modify the total solids, proteins, and mineral contents. However, it decreased pH values, changed the color to an orange hue, and decreased luminosity. The fermented lactic beverage added with probiotic and 10% guabiroba pulp showed 1.61× more phenolic compounds and an increase of 164% for each evaluated carotenoid content compared with the control beverage