bluuebunny/crossref_metadata_2025_split huggingface dataset:
COMPUTING OPTIMAL DYNAMIC EXPERIMENTS FOR MODEL CALIBRATION IN PREDICTIVE MICROBIOLOGY
Authors: BALSA‐CANTO E. , ALONSO A.A. , BANGA J.R. 
Published: February 2008

ABSTRACT The potential of mathematical models describing the microbial behavior during food processing and storage largely depends on their predictive capabilities and, in this concern, model calibration plays a crucial role. Unfortunately, model calibration may only be performed successfully if the sources of information are sufficiently rich. Therefore, a careful experimental design is required. This contribution formulated the optimal experimental design (OED) problem as a general dynamic optimization problem where the objective was to optimize a certain criterion depending on the Fisher information matrix. This formulation allows for more flexibility in the experimental design, including initial conditions, sampling times, experimental durations, time‐dependent manipulable variables and number of experiments as degrees of freedom. Moreover, the use of robust confidence regions for the parameter estimates was suggested as an alternative to evaluate the quality of the proposed experimental schemes. The OED for the calibration of the thermal death time and Ratkowsky‐type secondary models was considered for illustrative purposes, showing how the usually disregarded E‐optimality criterion results in the experimental schemes offering the best compromise precision/decorrelation among the parameters.PRACTICAL APPLICATIONSThis work addresses a general methodology for designing optimal dynamic experiments for the purpose of model calibration. This methodology is general in the sense that it may be applied to any type of food processing model, being particularly relevant for predictive microbiology and quality assessment as the experimentation is both time consuming and expensive.The main advantages of the proposed technique are twofold: on one hand, it is able to significantly reduce the overall experimental burden, contributing not only to simplify the experimental planning, devising the most adequate experiments, but also minimizing the number of experiments, and on the other hand, the resultant experiments provide the maximum quantity and quality of information to improve the predictive capabilities of the models under consideration, of key importance for process design, optimization and control.
EFFECTIVE DIFFUSION COEFFICIENTS BEHAVIOR IN OSMOTIC DEHYDRATION OF APPLE SLICES CONSIDERING SHRINKING AND LOCAL CONCENTRATION DEPENDENCE
Authors: RODRIGUES ALAN EDUARDO , MAURO MARIA APARECIDA 
Published: February 2008

ABSTRACT The mass transfer during osmotic dehydration of apple slices immersed in 40, 50 and 60% (w/w) aqueous sucrose solutions was investigated to evaluate the influence of solution concentration on diffusivities. In the mathematical model, the diffusion coefficients were functions of the local water and sucrose concentration. The mass transfer equations were, simultaneously, solved for water and sucrose using an implicit numerical method. Material coordinates following the shrinkage of the solid were used. The predicted concentration profiles were integrated and compared to experimental data, showing a reasonable agreement with the measured data. On average, the effective diffusion coefficients for water and sucrose decreased as the osmotic solution concentration increased; that is the behavior of the binary coefficients in water–sucrose solutions. However, the diffusivities expressed as a function of the local concentration in the slices varied between the treatments. Water diffusion coefficients showed a remarkable variation throughout the slice and unusual behavior, which was associated to the cellular structure changes observed in tissue immersed in osmotic solutions. Cell structure changes occurred in different ways: moderate plasmolysis at 40%, accentuated plasmolysis at 50% and generalized damage of the cells at 60%. Intact vacuoles were observed after a long time of exposure (30 h) to 40 and 50% solutions. Effects of the concentration on tissue changes make it difficult to generalize the behavior of diffusion coefficients. PRACTICAL APPLICATIONSThe main innovation introduced in this study is represented by the model formulation that allows simulation of the concentration profiles during osmotic dehydration with a reasonable degree of accuracy. The model is useful for the design and control of this process and of further operations such as convective drying, as nonhomogeneous initial conditions can be established. In addition, the diffusivities expressed as a function of the local concentration in the slices allows interpretation of some of the physical changes in plant tissues exposed to concentrated solutions.
SHELF LIFE OF WHEY PROTEIN‐COATED PISTACHIO KERNEL (PISTACIA VERA L.)
Authors: JAVANMARD MAJID 
Published: February 2008

ABSTRACT Dried pistachio kernels were coated with whey protein concentrate (WPC)/glycerol (Gly) solutions. Accelerated rancidity tests of uncoated and coated nuts were performed. Lipid oxidation in pistachios results in “flavor‐fade” and off‐flavor development. WPC‐based coatings are excellent oxygen barriers and have the potential to be formed as coatings on pistachio kernels to extend their shelf life. Thus, I hypothesized that whey protein isolate films formed as coatings on pistachios would reduce the rate of peanut lipid oxidation. The objectives of this study were to determine coated and uncoated pistachio kernels' oxidation in pistachios stored at ambient conditions. Nine different formulations of WPC‐based coatings were used to coat the pistachios. Besides an uncoated pistachio kernel reference, controls were used to investigate the effects of other ingredients in the coating formulation. The pistachio samples were stored in duplicate at ambient conditions for up to 24 weeks and then analyzed peroxide value (PV) and sensory properties. The objective of this work was to evaluate how WPC/lipid‐based edible coatings affect the development of rancidity. Products resulting from lipid oxidation were measured by PV as an indicator of the formation of hydroperoxide, the primary initial product of lipid oxidation. The results indicate that the coated samples were oxidized significantly slower than the reference (uncoated pistachios); hence, the predicted shelf life is longer for the coated samples. The control samples also showed a delay in oxidation. The results also indicate that the WPC coatings, regardless of composition or thickness, provided a glossy appearance that made the coated nuts very distinctive from the uncoated nuts. In addition, coated nuts were slightly darker. PRACTICAL APPLICATIONSEdible films and coatings add value to their products, increase shelf life and/or reduce packaging. Applications of interest to the food industry include:

coating oxygen‐sensitive foods such as nuts to extend shelf life and reduce packaging;
coating nuts to prevent oil migration into surrounding food components (e.g., nuts in chocolate).
TREATMENT OF CULTIVATED HIGHBUSH BLUEBERRIES (VACCINIUM CORYMBOSUM L.) WITH ELECTRON BEAM IRRADIATION: DOSIMETRY AND PRODUCT QUALITY
Authors: MORENO M.A. , CASTELL‐PEREZ M.E. , GOMES C. , DA SILVA P.F. , KIM J. , MOREIRA R.G. 
Published: February 2008

ABSTRACT We determined the dose distribution within a tray of highbush blueberries (Vaccinium corymbosum L.) exposed to electron beam irradiation at medium levels (1.0–3.2 kGy) using Monte Carlo and computer tomography scanning technology. We also evaluated the quality of irradiated and nonirradiated (control) fruits stored at 5C and 70% relative humidity during 14 days by a series of chemical analyses. Blueberries packed in plastic clamshell containers (trays) were irradiated using a 10‐MeV linear accelerator with single‐beam fixture (top only). Irradiation of blueberries at 1.1 kGy had no significant (P > 0.05) effect on the fruit quality with the exception of ascorbic acid, which decreased by 17% by the end of storage. Irradiation had an enhancing effect on the total phenolic and tannin content of all the irradiated fruits (10–20% increases). The calculated dose distribution in a pack of blueberries confirmed that the dose is not uniformly distributed within the pack because of density inhomogeneities (flesh, skin air). Dose levels at the bottom of the trays were 18 (±8%) higher than at the top. These results suggest that careful dose distribution examination must be conducted prior to setting up of an irradiation run for the packed fruits. Excellent agreement was found between measured and calculated doses at different electron beam conveyor speeds.PRACTICAL APPLICATIONSLittle information is available on how electron beam irradiation penetrates a complex medium such as packed blueberries. This study presents unique results from a dose distribution calculation method using Monte Carlo simulation and computed tomography scanning techniques, which can be an effective tool for the development of proper irradiation treatment planning of packed fruits and other fresh produce. The suitability of using electron beam technology to preserve the quality characteristics and shelf life of packed blueberries was verified.
The effect of trilostane treatment on circulating thyroid hormone concentrations in dogs with pituitary‐dependent hyperadrenocorticism
Authors: Kenefick S. J. , Neiger R. 
Published: February 2008

Objective:To assess thyroid hormone levels in hyperadrenocorticoid dogs before and after therapy with trilostane, a reversible inhibitor of steroidogenesis.Methods:Serum total thyroxine, free thyroxine and endogenous canine thyroid‐stimulating hormone concentrations were measured in 20 dogs with spontaneously occurring hyperadrenocorticism before and six months after successful treatment with trilostane.Results:Fourteen dogs demonstrated an increase in thyroxine following trilostane treatment; however, this was not significant (P=0·108). Fourteen dogs demonstrated an increase in canine thyroid‐stimulating hormone concentrations with trilostane therapy (P=0·006). Of the 14 dogs that demonstrated an increase in thyroxine concentrations following therapy, 10 also showed an increase in canine thyroid‐stimulating hormone concentrations. Before treatment, free thyroxine values were within, above and below the reference range in 10, six and two dogs, respectively. Sixteen of 18 dogs had free thyroxine values within the reference range after treatment, with 11 dogs showing a decrease in free thyroxine levels following therapy (P=0·029).ClinicalSignificance:While treatment with trilostane did not induce a significant change of thyroxine concentrations, there was a significant increase in canine thyroid‐stimulating hormone concentrations following treatment, a finding that supports thyroid‐stimulating hormone suppression as one of the factors that contributes to the effects of glucocorticoids on the hypothalamic‐pituitary‐thyroid axis. The significant elevation in free thyroxine values following treatment with trilostane was unexpected and did not support the findings of previous studies in this area.
Primary/Leakage Flow Interaction in a Pump Stage
Authors: Baskharone E. A. , Wyman N. J. 
Published: February 2008

Abstract
The finite-element analysis of the combined primary and leakage flow streams in a centrifugal pump is presented. To date, this computational model provides the most accurate “zeroth-order” flow field for rotordynamic calculations, short of analyzing the entire flow field on a fully three-dimensional basis. In formulating the problem, the shaft work is modeled via the angular momentum it imparts to the primary flow stream across the impeller blade region. In casting the boundary conditions, special attention is paid to the multi-connectivity of the newly-contoured computational domain in such a way to avoid over-specification of the problem. The analysis is applied to a typical pump stage with a face seal being part of the leakage passage. The numerical results are then compared to the outcome of the existing lower-order analysis where the impeller subdomain was totally extracted.
High Flux Rate Particle Filtration From Liquids
Authors: Chahine G. L. , Kalumuck K. M. , Aley Patrick D. , Frederick G. S. 
Published: February 2008

Abstract
A method for efficient solid particle removal from liquids using microporous tubes with flow swirl and flow interruption is presented. Experiments were performed using particle laden water obtained from an actual field project of high pressure water jet paint stripping. The flow rate, orientation, flow interruption, and swirl index were varied, and their effect on performance observed and measured as a function of time. Flux rate increases of a factor of 20 over a conventional microporous tube cross flow filtration were generated. Flux rates were found to increase both with increasing swirl and with moderate increases in the shear exerted on the tube wall. Results of independent testing by the US Navy at Port Hueneme of a small field unit demonstrate high flux rate performance with high permeate quality and turbidity removal.
Spatiotemporal Variability of Hourly Precipitation over the Eastern Contiguous United States from Stage IV Multisensor Analyses
Authors: Kursinski Ana L. , Mullen Steven L. 
Published: February 2008

Abstract
The statistical character of precipitation events from hourly stage IV analyses is documented for the eastern United States during the cool [December–February (DJF)] and the warm [June–August (JJA)] seasons for the four years of 2002–05. Isotropic e-folding distances and in situ e-folding times are computed for mesh sizes that vary from 4 km (the minimal stage IV pixel size) to 32 km for two thresholds: light (1 mm h−1) and heavy (5 mm h−1) precipitation rates. Marked seasonal variability characterizes the e-folding times. They typically run between 2 and 3 h during winter and 1 and 2 h during summer for light events, and they run an hour shorter for heavy rainfall during both seasons. Spatial decorrelation estimates also reveal considerable seasonal and geographical variability; e-folding distances typically lie between 60 and 180 km during the winter and between 30 and 60 km during the summer for light episodes, and they are approximately a factor of 2 to 3 shorter for heavy events. Anisotropic statistics are estimated by a simple geometric model. Hourly precipitation patterns show a preference for a southwest–northeast orientation during both seasons with greater elongation during the winter. Mean propagation velocities of precipitating systems are faster and are more closely aligned with the dilatation axis during the winter. These statistics should provide useful guidance for diagnosing and improving the spatiotemporal variance characteristics of precipitation for downscaling algorithms and numerical models of hydrometeorological prediction systems.
Probabilistic Quantitative Precipitation Forecast for Flood Prediction: An Application
Authors: Reggiani P. , Weerts A. H. 
Published: February 2008

Abstract
This paper outlines a methodology to produce probabilistic quantitative precipitation forecasts by means of a dedicated uncertainty processor for weather model output. The uncertainty processor is developed as a component of a Bayesian forecasting system for river flow prediction. In this context the quantitative precipitation forecast is envisaged as a mixed binary–continuous predictand. The processor is applied to the quantitative precipitation forecasts and to precipitation observations covering a 5-yr period, whereby the forecasted and observed relative air humidity are used as ancillary meteorological indicators. The application of the processor to the selected dataset highlights a significantly larger skill of the quantitative precipitation forecast in predicting event occurrence rather than event depth and provides an objective quantification of the forecast uncertainty. The methodology applied here remains restricted to small basins, in which spatial variability of precipitation can be considered negligible. The need for processing the uncertainty induced by spatial variability of rainfall is briefly addressed.
Correcting Errors in Streamflow Forecast Ensemble Mean and Spread
Authors: Wood Andrew W. , Schaake John C. 
Published: February 2008

Abstract
When hydrological models are used for probabilistic streamflow forecasting in the Ensemble Streamflow Prediction (ESP) framework, the deterministic components of the approach can lead to errors in the estimation of forecast uncertainty, as represented by the spread of the forecast ensemble. One avenue for correcting the resulting forecast reliability errors is to calibrate the streamflow forecast ensemble to match observed error characteristics. This paper outlines and evaluates a method for forecast calibration as applied to seasonal streamflow prediction. The approach uses the correlation of forecast ensemble means with observations to generate a conditional forecast mean and spread that lie between the climatological mean and spread (when the forecast has no skill) and the raw forecast mean with zero spread (when the forecast is perfect). Retrospective forecasts of summer period runoff in the Feather River basin, California, are used to demonstrate that the approach improves upon the performance of traditional ESP forecasts by reducing errors in forecast mean and improving spread estimates, thereby increasing forecast reliability and skill.
Characterization of Errors in a Coupled Snow Hydrology–Microwave Emission Model
Authors: Andreadis Konstantinos M. , Liang Ding , Tsang Leung , Lettenmaier Dennis P. , Josberger Edward G. 
Published: February 2008

Abstract
Traditional approaches to the direct estimation of snow properties from passive microwave remote sensing have been plagued by limitations such as the tendency of estimates to saturate for moderately deep snowpacks and the effects of mixed land cover within remotely sensed pixels. An alternative approach is to assimilate satellite microwave emission observations directly, which requires embedding an accurate microwave emissions model into a hydrologic prediction scheme, as well as quantitative information of model and observation errors. In this study a coupled snow hydrology [Variable Infiltration Capacity (VIC)] and microwave emission [Dense Media Radiative Transfer (DMRT)] model are evaluated using multiscale brightness temperature (TB) measurements from the Cold Land Processes Experiment (CLPX). The ability of VIC to reproduce snowpack properties is shown with the use of snow pit measurements, while TB model predictions are evaluated through comparison with Ground-Based Microwave Radiometer (GBMR), aircraft [Polarimetric Scanning Radiometer (PSR)], and satellite [Advanced Microwave Scanning Radiometer for the Earth Observing System (AMSR-E)] TB measurements. Limitations of the model at the point scale were not as evident when comparing areal estimates. The coupled model was able to reproduce the TB spatial patterns observed by PSR in two of three sites. However, this was mostly due to the presence of relatively dense forest cover. An interesting result occurs when examining the spatial scaling behavior of the higher-resolution errors; the satellite-scale error is well approximated by the mode of the (spatial) histogram of errors at the smaller scale. In addition, TB prediction errors were almost invariant when aggregated to the satellite scale, while forest-cover fractions greater than 30% had a significant effect on TB predictions.
The Seasonal Cycle of Gravity Wave Drag in the Middle Atmosphere
Authors: Pulido Manuel , Thuburn John 
Published: February 2008

Abstract
Using a variational technique, middle atmosphere gravity wave drag (GWD) is estimated from Met Office middle atmosphere analyses for the year 2002. The technique employs an adjoint model of a middle atmosphere dynamical model to minimize a cost function that measures the differences between the model state and observations. The control variables are solely the horizontal components of GWD; therefore, the minimization determines the optimal estimate of the drag. For each month, Met Office analyses are taken as the initial condition for the first day of the month, and also as observations for each successive day. In this way a three-dimensional GWD field is obtained for the entire year with a temporal resolution of 1 day. GWD shows a pronounced seasonal cycle. During solstices, there are deceleration regions of the polar jet centered at about 63° latitude in the winter hemisphere, with a peak of 49 m s−1 day−1 at 0.24 hPa in the Southern Hemisphere; the summer hemisphere also shows a deceleration region but much weaker, with a peak of 24 m s−1 day−1 centered at 45° latitude and 0.6 hPa. During equinoxes GWD is weak and exhibits a smooth transition between the winter and summer situation. The height and latitude of the deceleration center in both winter and summer hemispheres appear to be constant. Important longitudinal dependencies in GWD are found that are related to planetary wave activity; GWD intensifies in the exit region of jet streaks. In the lower tropical stratosphere, the estimated GWD shows a westward GWD descending together with the westward phase of the quasi-biennial oscillation. Above, GWD exhibits a semiannual pattern that is approximately out of phase with the semiannual oscillation in the zonal wind. Furthermore, a descending GWD pattern is found at those heights, similar in magnitude and sign to that in the lower stratosphere.
Mechanisms of Low Cloud–Climate Feedback in Idealized Single-Column Simulations with the Community Atmospheric Model, Version 3 (CAM3)
Authors: Zhang Minghua , Bretherton Christopher 
Published: February 2008

Abstract
This study investigates the physical mechanism of low cloud feedback in the Community Atmospheric Model, version 3 (CAM3) through idealized single-column model (SCM) experiments over the subtropical eastern oceans. Negative cloud feedback is simulated from stratus and stratocumulus that is consistent with previous diagnostics of cloud feedbacks in CAM3 and its predecessor versions. The feedback occurs through the interaction of a suite of parameterized processes rather than from any single process. It is caused by the larger amount of in-cloud liquid water in stratus clouds from convective sources, and longer lifetimes of these clouds in a warmer climate through their interaction with boundary layer turbulence. Thermodynamic effects are found to dominate the negative cloud feedback in the model. The dynamic effect of weaker subsidence in a warmer climate also contributes to the negative cloud feedback, but with about one-quarter of the magnitude of the thermodynamic effect, owing to increased low-level convection in a warmer climate.
Retrieval of Reflectivity in a Networked Radar Environment
Authors: Chandrasekar V. , Lim S. 
Published: February 2008

AbstractA system for reflectivity and attenuation retrieval for rain medium in a networked radar environment is described. Electromagnetic waves backscattered from a common volume in networked radar systems are attenuated differently along the different paths. A solution for the specific attenuation distribution is proposed by solving the integral equation for reflectivity and attenuation. The set of governing integral equations describing the backscatter and propagation of common resolution volume are solved simultaneously with constraints on total path attenuation. The proposed algorithm is evaluated based on simulated X-band radar observations synthesized from S-band measurements collected by the Colorado State University–University of Chicago–Illinois State Water Survey (CSU–CHILL) radar.Retrieved reflectivity and specific attenuation using the proposed method show good agreement with simulated reflectivity and specific attenuation. Preliminary demonstration of the network-based retrieval using data from the Center for Collaborative Adaptive Sensing of the Atmosphere (CASA) IP-1 radar network are also presented.