Quality characteristics of white wine: The short- and long-term impact of high power ultrasound processing

This research aimed to analyze the effects of ultrasound on the quality characteristics of white wine when processed by two different systems, i.e., ultrasonic bath and ultrasonic probe. In this regard, the multivariate statistical analysis and artificial neural network (ANN) techniques were used. Additionally, the efficiency of high power ultrasound (HPU) combined with sulfite and glutathione (GSH) treatments was explored during 18 months of bottle storage. Regarding ultrasonic bath experiment, the higher bath temperature caused the degradation of volatile compounds, precisely esters and higher alcohols, while the ultrasound effect on phenolic composition was much less pronounced. Interestingly, a combination of larger probe diameter and higher ultrasound amplitude showed a milder effect on phenolic and volatile composition in ultrasonic probe experiment. Both, ultrasonic bath and probe experiments did not cause great changes in the color properties. Moreover, implemented ANN models for flavan-3-ols, higher alcohols and esters resulted in the highest prediction values. HPU processing after 18 months of storage did not affect wine color. However, it modified phenolic and volatile composition, with greater effect in wines with lower concentration of antioxidants. In addition, there was no significant difference in the phenolic and volatile composition among sonicated low-sulfite-GSH wine and the one with standard-sulfite content. Therefore, a combined HPU and low-sulfite-GSH treatment might be a promising method for production of low-sulfite wines.     

Initiating a Mexican wave: An instantaneous collective decision with both short- and long-range interactions

An interesting example for collective decision-making is the so-called Mexican wave during which the spectators in a stadium leap to their feet with their arms up and then sit down again following those to their left (right) with a small delay. Here we use a simple, but realistic model to explain how the combination of the local and global interactions of the spectators produces a breaking of the symmetry resulting in the replacement of the symmetric solution—containing two propagating waves—by a single wave moving in one of the two possible directions. Our model is based on and compared to the extensive observations of volunteers filling out the related questionnaire we have posted on the Internet. We find that, as a function of the parameter controlling the strength of the global interactions, the transition to the single-wave solution has features reminiscent of discontinuous transitions. After the spontaneous symmetry breaking the two directions of propagation are still statistically equivalent. We also investigate how this remaining symmetry is broken in real stadia by a small asymmetrical term in the perception of spectators.     

An ergodic algorithm for long-term coverage of elliptical orbits

This paper deals with the coverage analysis problem of elliptical orbits. An algorithm based on ergodic theory, for long-term coverage of elliptical orbits, is proposed. The differential form of the invariant measure is constructed via the perturbation on mean orbital elements resulted from the $J_{2}$ term of non-spherical shape of the earth. A rigorous proof for this is then given. Different from the case of circular orbits, here the flow and its space of the dynamical system are defined on a physical space, and the real-value function is defined as the characteristic function on station mask. Therefore, the long-term coverage is reduced to a double integral via Birkhoff--Khinchin theorem. The numerical implementation indicates that the ergodic algorithm developed is available for a wide range of eccentricities.     

An ergodic algorithm for long-term coverage of elliptical orbits

This paper deals with the coverage analysis problem of elliptical orbits. An algorithm based on ergodic theory, for long-term coverage of elliptical orbits, is proposed. The differential form of the invariant measure is constructed via the perturbation on mean orbital elements resulted from the J2 term of non-spherical shape of the earth. A rigorous proof for this is then given. Different from the case of circular orbits, here the flow and its space of the dynamical system are defined on a physical space, and the real-value function is defined as the characteristic function on station mask. Therefore, the long-term coverage is reduced to a double integral via Birkhoff-Khinchin theorem. The numerical implementation indicates that the ergodic algorithm developed is available for a wide range of eccentricities.     

An evaluation method for nanoscale wrinkle

In this paper, a spectrum-based wrinkling analysis method via two-dimensional Fourier transformation is proposed aiming to solve the difficulty of nanoscale wrinkle evaluation. It evaluates the wrinkle characteristics including wrinkling wavelength and direction simply using a single wrinkling image. Based on this method, the evaluation results of nanoscale wrinkle characteristics show agreement with the open experimental results within an error of 6%. It is also verified to be appropriate for the macro wrinkle evaluation without scale limitations. The spectrum-based wrinkling analysis is an effective method for nanoscale evaluation, which contributes to reveal the mechanism of nanoscale wrinkling.     

An evaluation scheme for nanotechnology policies

Dozens of countries are executing national nanotechnology plans. No rigorous evaluation scheme for these plans exists, although stakeholders—especially policy makers, top-level agencies and councils, as well as the society at large—are eager to learn the outcome of these policies. In this article, we recommend an evaluation scheme for national nanotechnology policies that would be used to review the whole or any component part of a national nanotechnology plan. In this scheme, a component at any level of aggregation is evaluated. The component may be part of the plan’s overarching policy goal, which for most countries is to create wealth and improve the quality of life of their nation with nanotechnology. Alternatively, the component may be a programme or an activity related to a programme. The evaluation could be executed at different times in the policy’s life cycle, i.e., before the policy is formulated, during its execution or after its completion. The three criteria for policy evaluation are appropriateness, efficiency and effectiveness. The evaluator should select the appropriate qualitative or quantitative methods to evaluate the various components of national nanotechnology plans.     

An acoustic head simulator for hearing protector evaluation. I: Design and construction

As an alternative to subjective methods, an acoustic head simulator was constructed for hearing protector evaluation. The primary purpose of the device is for hearing protector testing and research under high-level steady-state and impulse noise environments. The design is based on the KEMAR manikin and therefore approximates the physical dimensions and the acoustical eardrum impedance of the median human adult. The head simulator includes a mechanical reproduction of the human circumaural and intraaural tissues with a silicone rubber material. A compliant head-neck system was constructed to approximate the vibrational characteristics of the human head in a sound field in order to simulate the inertia effect of earmuffs. The bone-conducted sounds are not mechanically reproduced in the design. Applications for the device are reported in a companion article [C. Giguère and H. Kunov, J. Acoust. Soc. Am. 85, 1197-1205 (1989)].     

An efficient method for evaluation of the complex probability function: The Voigt function and its derivatives

An efficient method is developed to evaluate the function w(z)=e^-z2(1+(2i/√π)∫^z₀e^t2dt) for the complex argument z = x + iy. The real part of w(z) is the Voigt function describing spectral line profiles; the imaginary part can be used to compute derivatives of the spectral line shapes, which are useful, e.g. in least-squares fitting procedures. As an example of the method a simple and fast FORTRAN subroutine is listed in the Appendix from which w(z) in the entire y ? 0 half-plane can be calculated, the maximum relative error being less than 2 × 10^-6 and 5 × 10^-6 for the real and imaginary parts, respectively.     

MRI assisted treatment planning for radiation therapy of the head and neck

Improved visualization of head and neck tumors has been demonstrated with the use of magnetic resonance imaging (MRI). Using standard plastic radiation therapy immobilization casts and an MR positive surface marker system developed in this institution, we have utilized MRI as an adjunct to the simulation of complex radiation treatments for tumors of the head and neck. This technique includes an indirect display of field margins and/or isodose curves over selected MR images. The lack of induced artifact from the immobilization cast, improved delineation of tumor extension from normal anatomy and the ability to image in arbitrary planes without changing patient positioning favor the use of MR over CT for radiation therapy planning in the head and neck, while ensuring reproducibility of the treatment plan at subsequent therapy sessions.     

An automatic evaluation system for NTA film neutron dosimeters

At CERN, neutron personal monitoring for over 4000 collaborators is performed with Kodak NTA films, which have been shown to be the most suitable neutron dosimeter in the radiation environment around high-energy accelerators. To overcome the lengthy and strenuous manual scanning process with an optical microscope, an automatic analysis system has been developed. We report on the successful automatic scanning of NTA films irradiated with ²³⁸Pu---Be source neutrons, which results in densely ionised recoil tracks, as well as on the extension of the method to higher energy neutrons causing sparse and fragmentary tracks. The application of the method in routine personal monitoring is discussed.     

Effect of short- and long-range forces on the structure of water: temperature and density dependence

The individual effects of short-range and long-range forces on the structure of water, a prerequisite for developing a perturbation theory, are assessed using a decomposition of realistic water—water potential models into trial potentials. Computer simulations for one typical liquid density and a number of temperatures ranging from the freezing temperature up to supercritical ones, and for several densities on a supercritical isotherm were performed. The trial potentials were constructed from the ST2 and TIP4P potentials and it is shown that for both potentials the results are practically identical. It is shown that (i) regardless of the thermo-dynamic conditions and potential models used, the structure of water and the mutual orientational arrangement of water molecules, given by a set of site—site correlation functions, are determined nearly exclusively only by the short range forces, and (ii) for high density states the effect of the short range electrostatic part of the intermolecular potential on the spatial arrangement of the water molecules rapidly decreases with increasing temperature but does not become negligible.     

Free cooling phase-diagram of hard-spheres with short- and long-range interactions

We study the stability, the clustering and the phase-diagram of free cooling granular gases. The systems consist of mono-disperse particles with additional non-contact (long-range) interactions, and are simulated here by the event-driven molecular dynamics algorithm with discrete (short-range shoulders or wells) potentials (in both 2D and 3D). Astonishingly good agreement is found with a mean field theory, where only the energy dissipation term is modified to account for both repulsive or attractive non-contact interactions. Attractive potentials enhance cooling and structure formation (clustering), whereas repulsive potentials reduce it, as intuition suggests. The system evolution is controlled by a single parameter: the non-contact potential strength scaled by the fluctuation kinetic energy (granular temperature). When this is small, as expected, the classical homogeneous cooling state is found. However, if the effective dissipation is strong enough, structure formation proceeds, before (in the repulsive case) non-contact forces get strong enough to undo the clustering (due to the ongoing dissipation of granular temperature). For both repulsive and attractive potentials, in the homogeneous regime, the cooling shows a universal behaviour when the (inverse) control parameter is used as evolution variable instead of time. The transition to a non-homogeneous regime, as predicted by stability analysis, is affected by both dissipation and potential strength. This can be cast into a phase diagram where the system changes with time, which leaves open many challenges for future research.     

The Joint Airborne IASI Validation Experiment: An evaluation of instrument and algorithms

The Joint Airborne IASI Validation Experiment (JAIVEx) was designed to investigate the absolute radiometric accuracy of the Infrared Atmospheric Sounding Interferometer (IASI) and test the radiative transfer algorithms on which applications using IASI radiances rely. Two comprehensively instrumented research aircraft participated in coordinated measurements co-aligned with overpasses on the IASI instrument, with airborne interferometers obtaining radiance observations alongside intensive measurements of the atmospheric state. The JAIVEx data set has been used to place an upper bound on the absolute radiometric accuracy of IASI radiances. Further, a set of clear air case studies have been used to test competing formulations of the CO₂ line shape, water vapor spectroscopic line parameters and continuum. The current state-of-the art performance of line-by-line models is established with implications for optimal use of IASI radiances in numerical weather prediction.     

An evaluation of molecular constants and transition probabilities for the NH free radical

Intense NH electronic emission spectra have been obtained from the low-density plume of an argon arc-jet ammonia introduced around the periphery. These spectra have been compared with spectra calculated by use of an IBM 360/50 computer from molecular constants, and the results of the computer comparison leading to a list of preferred molecular constants are included. Intensity measurements on emission spectra have yielded several previously unknown electronic-vibrational transition probabilities for different NH band systems. The electronic vibrational transition probabilities available from the literature are also included with an evaluation of the overlap of other band systems which apparently neglected in their original determination. The newly measured electronic-vibrational transition probabilities are as follows: A³Π → X³Σ^-A₀₁ = 1.30 × 10⁴sec^-1 A₁₀ = 0.5 × 10⁴ sec^-1 A₁₂ = 3.04 × 10⁴ sec^-1C¹Π → a¹δA₀₁ = 10.4 × 10⁴sec^-1C¹Π → b¹δ⁺A₀₀ = 7.45 × 10⁴sec^-1     

Depth-dependent mosaic tilt and twist in GaN epilayer:An approximate evaluation

An approach based on depth-sensitive skew-angle x-ray diffraction （SAXRD） is presented for approximately evalu- ating the depth-dependent mosaic tilt and twist in wurtzite c-plane GaN epilayers. It is found that （103） plane and （101） plane, among the lattice planes not perpendicular to the sample surface, are the best choices to measure the depth profiles of tilt and twist for a GaN epilayer with a thickness of less than 2 μm according to the diffraction geometry of SAXRD. As an illustration, the depth-sensitive （103）/（101） ω-scans of a 1.4-μm GaN film grown by metal-organic chemical vapor deposition on sapphire substrate are measured and analyzed to show the feasibility of this approach.