Spectra of ultrabroadband squeezed pulses and the finite-time Unruh-Davies effect

We study spectral properties of quantum radiation of ultimately short duration. In particular, we introduce a continuous multimode squeezing operator for the description of subcycle pulses of entangled photons generated by a coherent-field driving in a thin nonlinear crystal with second order susceptibility. We find the ultrabroadband spectra of the emitted quantum radiation perturbatively in the strength of the driving field. These spectra can be related to the spectra expected in an Unruh-Davies experiment with a finite time of acceleration. In the time domain, we describe the corresponding behavior of the normally ordered electric field variance.Comment: 11 pages, 5 figure

A Capacidade de rebrota das castanheiras.

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Efeito da aplicação do lodo de esgoto (Biossólido) sobre a produção e decomposição do folhedo de Eucalyptus grandis e sobre o retorno de nutrientes ao solo, em Itatinga-SP.

O tratamento do esgoto urbano gera um resíduo denominado lodo de esgoto que pode ser utilizado para aumentar a produtividade de culturas agrícolas e florestais. Este artigo apresenta o efeito que a aplicação de doses crescentes de biossólido (O a 40 tlha), produzido na ETE de Barueri da SABESP - SP, provocou sobre o retorno de nutrientes ao solo, através da produção de folhedo (derrubada de folhas senescentes das árvores) e também sobre a taxa de decomposição do folhedo acumulado sobre o solo (manta orgânica) em um talhão experimental de Eucalyptus grandis, localizado na Estação Experimental de Ciências Florestais da ESALQ/USP em Itatinga - SP. Após três anos de coleta mensal do folhedo, o tratamento onde foram aplicadas 40 t ha-1 de biossólido, depositou 4.828 kg ha-1 de folhedo a mais do que o testemunha, devolvendo ao solo cerca de cinco vezes mais Ca, duas vezes mais N e três vezes mais P. Foi registrado também um aumento de 40% na taxa de decomposição do folhedo, quando comparado com o tratamento testemunha. Os vários resultados obtidos na Estação Experimental de Ciências Florestais da ESALQ/USP em Itatinga, confirmam a hipótese de que a aplicação do biossólido altera os padrões de ciclagem dos nutrientes, intensificando o retorno de nutrientes e acelerando sua incorporação ao solo

Bidirectionality in multisensory perception: Examining the mutual influences between audition and taste

Previous research suggests that people reliably associate sounds and tastes. One important and often-cited implication of these crossmodal correspondences is the modulatory effect of sound on taste perception. In contrast, the potential impact of gustatory sensations on auditory perception has received less empirical attention. This paper presents the results of three experiments examining how listening to a sweet (vs. bitter) soundtrack shapes the sensory perception of bittersweet chocolate (Experiments 1a and 1b) and how the sweet (vs. bitter) taste of chocolate affects the perception of congruent sensory and hedonic attributes of a “bittersweet” soundtrack (Experiment 2). Experiment 1a manipulated the soundtrack type between participants and found no significant effect of music on taste perception. Experiment 1b followed a similar procedure but with a within-participants design. Here, the chocolate sample was perceived as sweeter and more positive when paired with the sweet soundtrack. In Experiment 2, tasting sweet chocolate shifted the evaluation of the bittersweet soundtrack toward higher sweetness and pleasantness and lower bitterness ratings. These findings suggest that sound-taste correspondences may have bidirectional effects on gustatory and auditory stimuli perception. However, the effects of audition on taste may depend on the direct contrast between soundtracks with different crossmodal profiles. These findings contribute to a better understanding of multisensory interactions between audition and taste. The implications for future research and the challenges to real-world interventions are discussed.info:eu-repo/semantics/publishedVersio

Subcycle squeezing of light from a time flow perspective

Light as a carrier of information and energy plays a fundamental role in both general relativity and quantum physics, linking these areas that are still not fully compliant with each other. Its quantum nature and spatio-temporal structure are exploited in many intriguing applications ranging from novel spectroscopy methods of complex many-body phenomena to quantum information processing and subwavelength lithography. Recent access to subcycle quantum features of electromagnetic radiation promises a new class of time-dependent quantum states of light. Paralleled with the developments in attosecond science, these advances motivate an urgent need for a theoretical framework that treats arbitrary wave packets of quantum light intrinsically in the time domain. Here, we formulate a consistent time domain theory of the generation and sampling of few-cycle and subcycle pulsed squeezed states, allowing for a relativistic interpretation in terms of induced changes in the local flow of time. Our theory enables the use of such states as a resource for novel ultrafast applications in quantum optics and quantum information.Comment: 24 pages, 7 figures (including supplementary information

Advances in imaging THGEM-based detectors

The thick GEM (THGEM) [1] is an "expanded" GEM, economically produced in the PCB industry by simple drilling and etching in G-10 or other insulating materials (fig. 1). Similar to GEM, its operation is based on electron gas avalanche multiplication in sub-mm holes, resulting in very high gain and fast signals. Due to its large hole size, the THGEM is particularly efficient in transporting the electrons into and from the holes, leading to efficient single-electron detection and effective cascaded operation. The THGEM provides true pixilated radiation localization, ns signals, high gain and high rate capability. For a comprehensive summary of the THGEM properties, the reader is referred to [2, 3]. In this article we present a summary of our recent study on THGEM-based imaging, carried out with a 10x10 cm^2 double-THGEM detector.Comment: 3 pages, 3 figures. Presented at the 10th Pisa Meeting on Advanced Detectors; ELBA-Italy; May 21-27 200

Optimal configuration of microstructure in ferroelectric materials by stochastic optimization

An optimization procedure determining the ideal configuration at the microstructural level of ferroelectric (FE) materials is applied to maximize piezoelectricity. Piezoelectricity in ceramic FEs differ significantly from that of single crystals because of the presence of crystallites (grains) possessing crystallographic axes aligned imperfectly. The piezoelectric properties of a polycrystalline (ceramic) FE is inextricably related to the grain orientation distribution (texture). The set of combination of variables, known as solution space, which dictates the texture of a ceramic is unlimited and hence the choice of the optimal solution which maximizes the piezoelectricity is complicated. Thus a stochastic global optimization combined with homogenization is employed for the identification of the optimal granular configuration of the FE ceramic microstructure with optimum piezoelectric properties. The macroscopic equilibrium piezoelectric properties of polycrystalline FE is calculated using mathematical homogenization at each iteration step. The configuration of grains characterised by its orientations at each iteration is generated using a randomly selected set of orientation distribution parameters. Apparent enhancement of piezoelectric coefficient $d_{33}$ is observed in an optimally oriented BaTiO$_3$ single crystal. A configuration of crystallites, simultaneously constraining the orientation distribution of the c-axis (polar axis) while incorporating ab-plane randomness, which would multiply the overall piezoelectricity in ceramic BaTiO$_{3}$ is also identified. The orientation distribution of the c-axes is found to be a narrow Gaussian distribution centred around ${45^\circ}$. The piezoelectric coefficient in such a ceramic is found to be nearly three times as that of the single crystal.Comment: 11 pages, 7 figure

The taste & affect music database: Subjective rating norms for a new set of musical stimuli

Music is a ubiquitous stimulus known to influence human affect, cognition, and behavior. In the context of eating behavior, music has been associated with food choice, intake and, more recently, taste perception. In the latter case, the literature has reported consistent patterns of association between auditory and gustatory attributes, suggesting that individuals reliably recognize taste attributes in musical stimuli. This study presents subjective norms for a new set of 100 instrumental music stimuli, including basic taste correspondences (sweetness, bitterness, saltiness, sourness), emotions (joy, anger, sadness, fear, surprise), familiarity, valence, and arousal. This stimulus set was evaluated by 329 individuals (83.3% women; Mage = 28.12, SD = 12.14), online (n = 246) and in the lab (n = 83). Each participant evaluated a random subsample of 25 soundtracks and responded to self-report measures of mood and taste preferences, as well as the Goldsmiths Musical Sophistication Index (Gold-MSI). Each soundtrack was evaluated by 68 to 97 participants (Mdn = 83), and descriptive results (means, standard deviations, and confidence intervals) are available as supplemental material at osf.io/2cqa5. Significant correlations between taste correspondences and emotional/affective dimensions were observed (e.g., between sweetness ratings and pleasant emotions). Sex, age, musical sophistication, and basic taste preferences presented few, small to medium associations with the evaluations of the stimuli. Overall, these results suggest that the new Taste & Affect Music Database is a relevant resource for research and intervention with musical stimuli in the context of crossmodal taste perception and other affective, cognitive, and behavioral domains.info:eu-repo/semantics/acceptedVersio