One-dimensional Cylinder Research Articles

Температурные изменения в мясных изделиях при жарке в пароконвекционных печах

Combination steam ovens, or combi steamers, have entered all spheres of food production, including the meat industry. Their rational use requires a scientific and practical foundation. This research featured the changes in mean volume temperature and temperature gradient that occur in meat products (one-dimensional bodies with different nutrient compositions) during heat treatment in dry air and a steam-air mix.
 The research involved two samples of meat products with different moisture and fat contents. The chicken fillet sample had a moisture content of 74.5% and a fat content of 1.9% while the pork shoulder sample had a moisture content of 55.1% and a fat content of 29.4%. Shaped as a one-dimensional cylinder and a plate, the samples were subjected to heating at the temperature range of 160–240°C in a Unox-203G steam-convection oven (Italy). Dry air and a steam-air mix with a humidity of 80–85% served as a heating medium. The temperature was measured using thermocouples attached to a Sosna-004 meter.
 The research revealed some patterns in the mean volume temperature and temperature gradient. The temperature gradient involved three stages during processing in a steam-air mix and four stages when treated with dry air. The change in the mean volume temperature for the steam-air mix could be described by a power law equation; the dry air treatment was described using a linear equation. When heated in dry air, the rate of change in the temperature gradient was constant at first but started to decrease at a certain stage. The change rate in the mean volume temperature remained low for 5 min and started to increase onwards, maintaining its value until the end of the process. When heated in a steam-air mix, the change rate in the temperature gradient dropped to its minimum in 4–5 min and started to grow. The mean volume temperature demonstrated a high change rate during the first 5 min and went down. The chicken fillet with its low fat content warmed up faster by 13–26% when processed in a steam-air mix and by 9–23% when treated in dry air. The plate-shaped products needed longer heat treatment. The composition and form had no significant effect on the nature of the change in the temperature gradient and mean volume temperature.
 The obtained dependencies made it possible to select the optimal temperature and humidity conditions for convective frying of meat products.

An open-source project for wind instrument modeling using digital waveguides

Digital waveguide methods for time-domain modeling of acoustic structures comprised of interconnected piece-wise one-dimensional cylinders, cones and toneholes have been well reported in the past. In this work, an open-source Matlab class is presented that can be used to model arbitrary wind instrument air column structures, defined by length, radii and hole geometric parameters, using digital waveguide methods. Fractional-delay filtering can be enabled or disabled, with support for both Thiran and Lagrange filter types of specified order. Thermoviscous losses can be modeling using either a discrete-time least squares or a shelf-filter fit, both of arbitrary order. Three different tonehole model options are provided (two-port, three-port or wave digital filter). End boundary conditions include closed, anechoic, ideally open, open flanged and open unflanged. The class object can be used either in single-sample iterative contexts (for example, with an attached excitation model) or with arbitrarily-sized input signals (for example, to compute a reflection function or impedance). The modeled geometry can be constructed manually by iteratively adding segments or holes, or a complete geometry can be specified in a file. This project is bundled together with a parallel and previously reported open-source project for frequency-domain transfer matrix modeling of air columns (https://github.com/garyscavone/acmt).

The rate of temperature increase in the inner layers of meat products during heat treatment in steam-air environments

Studies have been conducted to study the rate of temperature increase in the subcortical and central layers of meat products with a different ratio of moisture/fat content when heated in steam-air environments. Skinless chicken fillet (wet fat- free sample) was selected as the objects of research SBI, humidity – 74.5%, fat content – 1.4%) and the meat of the shoulder part of the pork carcass (low-moisture, greasy sample), humidity – 55.1%, fat content - 29.4%). The products were molded in the form of a one-dimensional cylinder and plate. Heating was carried out in an environment of dry air and a vapor–air mixture with a moisture content of 80-85% at coolant temperatures of 160 ... 240 °С. Measurements were carried out in the subcortical layer (upper moist) and in the center (inner moist). The general rates of temperature increase in the studied layers are determined, the observed patterns are described. For a more complete description, the process was divided into periods of heating and bringing to readiness; a variant of separation by heating rate was selected, which was carried out based on the results of an analysis of changes in excess temperature over time. To analyze the presented data, the ratios of the rates of temperature increase were calculated depending on the type of coolant and the sample. It is shown that the rate of temperature increase increases with an increase in the temperature of the coolant at both treatment periods for all the studied variants. At the initial stage, a higher rate of temperature increase is observed when heated in a vapor–air mixture (due to the predominant heat transfer due to condensation), at the main stage - in the air (due to the predominant heat transfer due to convection). For the subcortical layer, at the initial stage, a higher temperature increase is observed for the low-moisture, greasy sample, at the main stage – for the wet fat- free sample (due to the evaporative capacity of the material). For the center, a higher increase is observed for the wet fat- free sample in both periods (due to the inhibitory effect of the fat melt of the low-moisture, greasy sample).

Electromagnetic diffraction properties of randomly aligned one-dimensional cylinders.

A new approach to electromagnetically analyzing random structures is proposed. By increasing a grating period consisting of a deterministic random structure, optical performance of the element approaches a certain converged value. Thus, characterizing random structures becomes possible in a single-run computation without a statistical procedure. We demonstrate the performance of this method using one-dimensional cylinder arrays.

Conjugated Polymer Chains Confined in Vertical Nanocylinders of a Block-Copolymer Film: Preparation, Characterization, and Optoelectronic Function

Hybrid materials composed of phase-separated block copolymer films and conjugated polymers of the phenylenevinylene family (PPV) are prepared. The PPV chains are embedded in vertical cylinders of nanometer diameter in the block-copolymer films. The cylinders span continuously the whole film thickness of 70 nm. Incorporation of the PPV chains into the one-dimensional cylinders leads to modified photoluminescence spectra and to large absorption anisotropy. The hybrid films show electroluminescence from the PPV chains in a simple light-emitting device at minute doping concentrations, and also exhibit a factor of 19 increase in electron transport efficiency along the single PPV chains.

A novel one-dimensional silver cylinder stabilized by mixed 2-mercaptobenzoic acid and ethylenediamine ligands

A novel infinite one-dimensional silver cylinder, namely poly[μ-ethylenediamine-μ(5)-(2-sulfanidylbenzoato)-μ(4)-(2-sulfanidylbenzoato)-tetrasilver(I)], [Ag(4)(C(7)H(4)O(2)S)(2)(C(2)H(8)N(2))](n), has been synthesized by one-pot reaction of equivalent molar silver nitrate and 2-mercaptobenzoic acid (H(2)mba) in the presence of ethylenediamine (eda). One Ag atom is located in an AgS(2)NO four-coordinated tetrahedral geometry, two other Ag atoms are in an AgS(2)O three-coordinated T-shaped geometry and the fourth Ag atom is in an AgSNO coordination environment. The two mba ligands show two different binding modes. The μ(2)-N:N'-eda ligand, acting as a bridge, combines with mba ligands to extend the Ag(I) ions into a one-dimensional silver cylinder incorporating abundant Ag···Ag interactions ranging from 2.9298 (11) to 3.2165 (13) Å. Interchain N-H···O hydrogen bonds extend the one-dimensional cylinder into an undulating two-dimensional sheet, which is further packed into a three-dimensional supramolecular framework by van der Waals interactions; no π-π interactions were observed in the crystal structure.

Formation of layered fracture and outburst during gas hydrate dissociation

Hydrate dissociation in marine sediments may cause large hazards. Two types of new hazard phenomena, outburst and layered fracture, are observed in laboratory experiments and the initiation mechanism is discussed. Experiments are carried out in a two-dimensional rectangular box and a one-dimensional cylinder, respectively. It is shown that layered fracture and outburst can appear after hydrate dissociation and are related closely to dissociation speed, permeability, strength of hydrate-bearing sediment and over-layered stratum. Outburst often occurs at low permeability, high strength of over layered stratum and high pore pressure, while layered fracture is just on the contrary.

An Angular Leakage Correction for Modeling a Hemisphere, Using One-Dimensional Spherical Coordinates

A radially dependent, angular leakage correction was applied to a one-dimensional, multigroup neutron diffusion theory computer code to accurately model hemispherical geometry. This method allows the analyst to model hemispherical geometry, important in nuclear criticality safety analyses, with one-dimensional computer codes, which execute very quickly. Rapid turnaround times for scoping studies thus may be realized. This method uses an approach analogous to an axial leakage correction in a one-dimensional cylinder calculation. The two-dimensional Laplace operator was preserved in spherical geometry using a leakage correction proportional to 1/r2, which was folded into the one-dimensional spherical calculation on a mesh-by-mesh basis. Hemispherical geometry is of interest to criticality safety because of its similarity to piles of spilled fissile material and accumulations of fissile material in process containers. A hemisphere also provides a more realistic calculational model for spilled fissile material than does a sphere.

Flux buildup in field reversed configurations using rotating magnetic fields

Rotating magnetic field (RMF) current drive is a very attractive method for both increasing the flux and sustaining the current in field reversed configurations (FRC). It has been demonstrated in low temperature, low field rotamaks, and will now be applied to a new translation, confinement, and sustainment (TCS) experiment attached to the LSX/mod (Large s field-reversed configuration Experiment) facility [Hoffman et al. Fusion Technol. 23, 185 (1993)]. Previous RMF calculations have been concerned primarily with the plasma currents and particle orbits produced in one-dimensional cylinders with the rotating field strength of near equal magnitude to the confining axial field. Both fluid current and particle orbits are calculated here in the more interesting regime appropriate to TCS and reactors where the confinement field far exceeds the rotating field strength. New insight is gained into both the flux buildup requirements for two-dimensional equilibria and into the limits on ion rotation in this high confinement field regime.

Finite-Dimensional Distributions and Tail Behavior in Stationary Interval-Valued Probability Models

We consider the relationship between the finite-dimensional distributions of a stationary time series model and its asymptotic behavior in the framework of interval-valued probability (IVP), a simple generalization of additive probability measures. By Caratheodory's theorem, the specification of a countably additive probability measure on the algebra of cylinders $\mathscr{C}$ uniquely defines its behavior on $\sigma(\mathscr{C})$ (containing the tail events). If the measure is stationary, then the ergodic theorem indicates that its extension assigns zero probability to the tail event consisting of all sequences for which the time averages diverge (the divergence event). This link between the marginals and the tail behavior is no longer valid in IVP, and we can reconcile arbitrary finite-dimensional distributions and tail behavior for stationary IVP-based models. The linking mechanism between the marginals of a time series model and its asymptotic behavior turns out to be continuity, not stationarity or even additivity. We prove that any stationary finitely additive probability (charge) defined on cylinders has a stationary charge extension that can assign the divergence event any prescribed probability. Moreover, on the space of binary sequences, we consider IVP models that incorporate: (i) Stationarity. (ii) Continuity along $\mathscr{C}$. (iii) Almost sure support for divergence. (iv) Estimability of the divergence event from cylinders. (v) Nearly additive finite-dimensional distributions. We enhance the previous constructions of IVP's satisfying (i)-(iv) so that they satisfy (v) by agreeing with a stationary measure either exactly on one-dimensional cylinders or arbitrarily closely on a given class of bounded-dimensional cylinders. Our time series constructions follow from the observation that the algebra of cylinders and the tail $\sigma$-algebra are mutually nonsingular. We use the same idea to prove the existence of joints for general marginal IVP's. These constructions have implications for frequentist interpretations of probability.

Effect of linear-anisotropic scattering on spectral emission from cylindrical plumes

The corresponding integral form of the equation of radiative transfer in absorbing, emitting, linear-anisotropic scattering media is used to compute the spectral hemispherical and the spectral plume emissivities of a onedimensional cylinder. The solution is based on using power series representations of the temperature and incident radiation profiles. The expansion coefficients for the temperature are assumed known, whereas the expansion coefficients for the incident radiation are solved for by the application of a collocation strategy based on the zeros of the Chebyshev polynomials. The method of solution is employed to study primarily the interaction between an absorbing/emitting gas phase and an absorbing/emitting/scattering particle phase. The numerical results indicate that the plume emissivity is enhanced by as much as 20% by the presence of purely scattering particles.

Fundamental Mode Decay Constants for Small Two- and Three-Dimensional Pulsed Neutron Moderator Assemblies

A method has been developed to calculate the fundamental mode decay constants in two- and three-dimensional pulsed neutron moderator assemblies using the separable form of the scattering kernel in the transport equation. The method uses the Fourier transform of the integral transport equation and is an extension of the method developed by Sahni to treat monoenergetic criticality problems for two- and three-dimensional geometries. The new kernel of the integral transform equation is factored into components depending on only one of the dimensions of the assembly. This property is further exploited by use of a single Fourier mode approximation in one or more dimensions while the kernels in the remaining dimensions are retained in their respective forms. In our numerical work, three simple forms of the scattering cross section are used for calculating the matrix elements of the relevant equations accurately. Numerical results are presented for the asymptotic decay constant in a one-dimensional slab, a one-dimensional cylinder, two-dimensional infinite rectangular prisms, and three finite cylinders of different height-to-diameter ratios. The relation between the asymptotic decay constant and the geometrical buckling in the transport and diffusion approximations are also calculated for interpreting the results in terms of extrapolation lengths.

Some considerations on neutron instrumentation requirements for malfunction diagnosis in power reactors using noise analysis techniques

To determine the response of a neutron detector to local perturbations in a typical fast breeder reactor detailed numerical calculations of space-dependent source transfer functions were performed for the German prototype reactor SNR 300. The small local reactivity perturbations considered here were replaced by a neutron source modulation for simplicity reasons. The source transfer function was obtained from the Laplace transform of the time-dependent inhomogeneous diffusion equation. The 26 groups KFK INR cross section set and one-dimensional cylinder geometry were used for the numerical solution of the diffusion equation in the frequency domain. The detector was treated as an integral part of the reactor. The detector materials B-10, U-235 and Pu-239 were chosen for comparison. The positions of source and detector were independently varied within the core and blanket of the reactor. From the space-dependent transfer function of the reactor-detector system and the general theory, relating power spectral densities of neutron detector signals and reactivity perturbations for the point reactor model, the neutron instrumentation requirements for detecting local perturbations in a fast reactor were deduced. It was found that in the present class of fast breeder prototype reactors no in-core neutron detectors will be needed for a continuous inspection using noise analysis techniques to detect local perturbations.