bluuebunny/crossref_metadata_2025_split huggingface dataset:
Melatonin accelerates metamorphosis in Xenopus laevis
Authors: Rose Matthew F. , Rose Susan R. 
Published: February 2007

Rose MF, Rose S.R. Melatonin accelerates metamorphosis in Xenopus laevis. J. Pineal Res. 1998; 24:90–95. © Munksgaard, CopenhagenAbstractDelayed metamorphosis associated with large body size has been observed in Woodhousei fowleri tadpoles reared in continuous dark (DD). To evaluate the mechanism by which DD delayed metamorphosis, light‐cycle exposure was controlled and thyroxine (T4), melatonin, or drugs that alter prolactin (Prl) concentrations were given to Xenopus laevis tadpoles. It was hypothesized that exogenous melatonin would delay metamorphosis and increase body size, and that elevation of Prl concentrations would have effects similar to melatonin exposure. Xenopus laevis tadpoles were randomized to three light conditions [light/dark (LD, 12 h/12 h), DD, and continuous light (LL)] and subgroups in each light condition were treated with T4, melatonin, bromocriptine (Bro), haloperidol (Hal), or no drug. Each subgroup included 12 tadpoles. Drugs were administered in the water either continuously or daily from 07.00 to 19.00 h (Intermittent). Measurements of total length, leg length, and stage of metamorphosis were obtained at regular intervals. DD resulted in delayed metamorphosis, while LL did not. T4 accelerated metamorphosis as expected, countering the delaying effects of DD. In contrast to the hypothesis, melatonin accelerated metamorphosis and impaired body size compared to controls. Intermittent Hal also accelerated metamorphosis, while Bro delayed it. In DD, both T4 and melatonin led to increased tadpole size in contrast to their counterparts in LD or LL. Delayed metamorphosis in DD is not caused by increased melatonin production. Melatonin and Hal (as given in this study) accelerate metamorphosis. Melatonin acceleration of metamorphosis may occur through alteration of the concentration of prolactin.
Altered circadian melatonin secretion patterns in relation to sleep in patients with chronic sleep‐wake rhythm disorders
Authors: Rodenbeck Andrea , Huether Gerald , Rüther Eckart , Hajak Goran 
Published: February 2007

Rodenbeck A, Huether G, Rüther E, Hajak G. Altered circadian melatonin secretion patterns in relation to sleep in patients with chronic sleep‐wake rhythm disorders. J. Pineal Res. 1998; 25:201–210. © Munksgaard, CopenhagenAbstractHuman well‐being depends on the entrainment of endogenous circadian rhythms of biological functions and the sleep‐wake rhythm. Although the incidence of otherwise healthy subjects with chronically altered sleep‐wake rhythms is rather low, the investigation of these patients provides new sights into circadian entrainment mechanisms. We therefore examined the circadian rhythm of circulating melatonin and the sleep‐wake rhythm in five patients with chronic sleep‐wake rhythm disorders and ten age‐matched healthy controls. All patients showed altered circadian melatonin rhythm parameters in relation to their sleep‐wake cycle compared to age‐matched controls. These alterations were random, i.e., independent of the type, the duration, and the age of onset of the disorder. The melatonin onset to sleep onset interval varied between the patients and the melatonin acrophase to sleep offset interval was prolonged in four patients. These findings indicate individual phase relations between the circadian melatonin rhythm and the sleep‐wake cycle in patients with chronic sleep‐wake rhythm disorders. Since the prolonged melatonin acrophase to sleep offset interval was the most consistent finding independent of aetiological origins, this abnormality may be one possible maintaining factor in chronic sleep‐wake rhythm disorders due to reduced phase‐resetting properties of the circadian pacemaker. Furthermore, rather low circadian melatonin amplitudes and a subsensitivity to daylight may maintain the disorder in at least some patients.
ENGINEERING ANALYSIS OF SOY DOUGH RHEOLOGY IN EXTRUSION
Authors: JAO Y. C. , CHEN A. H. , LEWANDOWSKI D. , IRWIN W. E. 
Published: February 2007

ABSTRACTEffects of moisture level, temperature and shear rate on the rheological properties of defatted soy dough during extrusion were studied on a Brabender laboratory extruder. Entrance pressure loss through the extruder capillary die as well as viscosity of the cooked and compressed soy dough were expressed as a function of added moisture, shear rate and temperature through multiple regression analysis. Process conditions involved in this study were (a) temperature from 100 to 160°C; (b) added moisture from 22 to 32% and (c) shear rate from 50 to 10,500 sec−1. Data were collected at steady state. It was found that in the shear rate range of 50 to 1,000 sec−1 and temperature range of 100 to 160°C the viscosity of the cooked and compressed soy dough with 32%, 25% and 22% added moisture ranged from 10,000 to 500 poise and 20,000 to 200 poise and 20,000 to 1,000 poise respectively.
THE EFFECTS OF DESIGN AND OPERATING CONDITIONS ON PARTICLE MORPHOLOGY FOR SPRAY‐DRIED FOODS
Authors: GREENWALD C. GAIL , KING C. JUDSON 
Published: February 2007

ABSTRACTAn experimental program was carried out in order to provide insight into the effects of the design and operating conditions of spray drying on the morphological behavior of the product. Single streams of uniform‐size drops fell through a column in which air temperature profiles could be monitored and manipulated. Scanning electron microscopy and optical microscopy were used to measure shrinkage (or expansion) and to observe physical characteristics. The effects of varying the type of feed, the feed concentration, initial drop size, and air temperature history were investigated. Results are compared with previous investigations related to bulk density.
EFFECTS OF RECOVERY METHODS ON THE FUNCTIONALITY OF PROTEIN CONCENTRATES FROM FOOD PROCESSING WASTES1
Authors: KNORR D. 
Published: February 2007

ABSTRACTThe multiple effects of the method of protein recovery on food protein functionality are presented. The results indicate the influence of method of protein coagulation (heat coagulation versus coagulation at room temperature) and type of coagulant (HCl, FeCl3, Al2(SO4)3, citric acid) on protein solubility, water binding capacity and baking properties. Dehydration conditions such as air inlet/outlet temperature (120‐125/42‐42° C to 190‐195/70‐72°C) or pH of the protein coagulate (pH 4 to 8) as well as methods of dehydration (freeze‐, spray‐, drum‐drying) affected the water binding capacity and protein solubility of plant protein concentrates. Insignificant correlations (P < 0.01) existed between solubility values and water binding capacity data. Marked effects of the interactions between method of dehydration, protein source or dehydration temperature and pH of the coagulate on protein functionality were found.Based on the data presented it is proposed to develop processes for the production of protein concentrates with “tailored” functionality by selecting specific protein recovery processes and by mixing differently processed protein concentrates.
A REVIEW ON PREDICTING FREEZING TIMES OF FOODS
Authors: RAMASWAMY H. S. , TUNG M. A. 
Published: February 2007

ABSTRACTHeat transfer during freezing of a food material involves a complex situation of simultaneous phase transition and changing thermal properties. Models for predicting freezing times range from relatively simple analytical equations based on a number of assumptions and approximations, to the more versatile numerical methods which require the use of a sophisticated computer. The necessity for having a consistent definition for freezing time, the nature of the freezing process, different prediction models and thermo‐physical properties of importance are discussed in view of the mathematics of freezing time computations. In this review, attention has been focused on established analytical models which can be solved without resorting to computer techniques. The review points out the need for further refinement of the existing Plank‐type models to facilitate accurate freezing time estimations under a wide range of practical conditions.
MODELING HEAT AND MASS TRANSFER DURING THE OVEN ROASTING OF MEAT
Authors: SINGH NEERA , AKINS R. G. , ERICKSON L. E. 
Published: February 2007

ABSTRACTThe roasting (baking) of meat involves both heat and mass transfer. A mathematical model which describes the roasting process as it occurs in a conventional oven is presented. Numerical solutions are presented for several different roasting conditions and the results are compared to available experimental results. A significant fraction of the energy required for roasting is associated with the evaporation of water and this needs to be considered in modeling the roasting process. Water losses due to mass transfer from the product depend on oven humidity and temperature. The mathematical model considers the variation of oven humidity with time during roasting. The implicit alternating direction finite difference method is used to obtain the numerical solutions.
HEAT TRANSFER COEFFICIENTS to NEWTONIAN LIQUIDS IN AXIALLY ROTATED CANS
Authors: SOULÉ CARLOS LUCIO , MERSON RICHARD L. 
Published: February 2007

ABSTRACTOverall heat transfer coefficients to water and silicone fluids in cans rotating in a steam retort were correlated by (Eq. A):

image

where the Reynolds number, pND2/μ, based on the rotational speed of the can, was varied over the range 12 < Re <44,000, the Prandtl number c0μ/k was tested between 2.2 and 2300, the can length to diameter ratio was varied over 1.11 < L/D<1.61, and the ratio of bulk to wall viscosities, μb/μw, was varied between 1.22 and 1.79. All fluid properties were evaluated at the arithmetic average of the initial and final temperatures of the can wall. Data for 106 trials were correlated with a multiple regression correlation coefficient of R’= 0.916. Internal film coefficients were about 7% higher than U values and can be calculated by h = (1.07 ± 0.04) U.
QUANTITATIVE ANALYSIS OF TEXTURE CHANGE IN COD MUSCLE DURING FROZEN STORAGE
Authors: KIM YOON J. , HELDMAN DENNIS R. 
Published: February 2007

ABSTRACTThe textural deterioration of cod muscle during frozen storage was investigated by objective measurement using the Instron Universal Testing Machine. The rates of texture change as a function of storage time revealed that the increased toughness and decreased cohesiveness could be described by a first‐order relationship. Higher storage temperatures resulted in more rapid rates of textural deterioration. Larger activation energy constants for toughness of cod muscle as compared to cohesiveness indicated that toughening was more temperature dependent than cohesiveness. The increased toughness and the decreased cohesiveness of frozen‐stored fish appeared to be related to the protein denaturation of the cod muscle and the loss of water‐holding capacity, respectively.
ACTIVITY COEFFICIENTS of AROMA COMPOUNDS and WATER ACTIVITY IN MODEL SYSTEMS
Authors: VOILLEY A. 
Published: February 2007

ABSTRACTOne aim of this work was to measure the activity of water and aroma compounds in aqueous solutions simultaneously.The volatilities of aroma substances at infinite dilution in aqueous solutions of polyethylene‐glycols (PEG) were studied. the activity coefficients (γi∞) of volatile compounds were measured by gas stripping (exponential dilution). This dynamic method also allowed the measurement of the water activity of these solutions. the results showed that:

the influence of polyethylene‐glycols on γi∞ depended most strongly on the PEG mass fraction in the solution. the effect of the PEG molecular weight was not significant.
γi∞ increased as molecular weight and length increased for the homologous series of alcohols tested. This can be explained by entropic effects. Probably, the same effect occurs for other homologous series.
γi∞ for 2‐propanone increased as temperature increased. Based on this relation, molar partial excess enthalpies of mixing were calculated for 2‐propanone in an aqueous solution.
EFFECTS of FEED MOISTURE and BARREL TEMPERATURE ON the RHEOLOGICAL PROPERTIES of EXTRUDED COWPEA MEAL1
Authors: KENNEDY M. B. , PHILLIPS R. D. , RAO V. N. M. , CHINNAN M. S. 
Published: February 2007

ABSTRACTDecorticated cowpea meal was adjusted to 20, 30, and 40% moisture and extruded in a Wayne pilot‐scale extruder at barrel temperatures of 150, 175 and 200°C. the resulting products were subjected to rheological evaluation using the Instron Universal Testing Machine equipped with standard tensile jaws, the Warner‐Bratzler shear device and the Kramer Shear Press. Regression equations relating rheological properties to feed moisture and barrel temperature were computed from the data, and response surfaces were generated from these models. Tensile strength of extrudates was greatest for the dense products produced in the low moisture‐low temperature region and declined at higher moistures and temperatures. Shear strength as determined by either the Warner‐Bratzler or Kramer devices exhibited a ridge of high values extending from 20%‐150°C to 30%‐200°C, and declined for brittle, expanded products made at low moisture and high temperature and for soft products made at high moisture.
SCRAPED SURFACE HEAT EXCHANGERS
Authors: HÄRRÖD MAGNUS 
Published: February 2007

ABSTRACTIn this literature survey flow patterns, mixing effects, heat transfer and power required for rotation in scraped surface heat exchangers (SSHE) are thoroughly discussed, with the emphasis on assumptions and results, while the principal design of different SSHEs are only briefly discussed.The flow patterns control the desired radial mixing and the undesired axial mixing. the flow in a SSHE can be regarded as the sum of an axial flow and a rotational flow. the axial flow is laminar and the rotational flow is laminar or vortical.With laminar flow the radial mixing is poor, which causes poor heat transfer and allows the axial flow profile to control the residence time distribution. the precise onset of vortical flow in a SSHE is hard to predict. the vortical flow makes the radial mixing very efficient, giving good heat transfer and perhaps plug flow behavior. However, vortical flow also causes axial mixing which reduces the apparent heat transfer coefficient and increases the residence time distribution.The power required to rotate the shaft and blades is mainly determined by the design of the blades.
AVERAGE SPECIFIC CAKE RESISTANCE DETERMINED IN the PRESENCE of SEDIMENTATION to FILTRATION of STARCH SLURRY UNDER CONSTANT PRESSURE
Authors: TAKAI RIKUO , ABE HIROSHI , WATANABE HISAHIKO , HASEGAWA HIROSHI , SAKAI YOSHIO 
Published: February 2007

ABSTRACTAn equation for predicting filtration flow rates in the presence of sedimentation at constant pressure drop was developed. It was applied to determine the average specific cake resistance infiltration of starch slurries at 18.8 to 115 kPa pressure drop range. At these conditions, corn, potato and sweet potato starch filter cakes were incompressible but wheat starch cake was compressible.
EXPERIMENTAL VERIFICATION and USE of PRESSURIZED CAN MODELS
Authors: BREWBAKER PHILIP L. , HENDERSON JERALD M. 
Published: February 2007

ABSTRACTThe results of an experimental investigation of the strength characteristics of pressurized food cans are compared with existing models of thin‐walled cylinders as they pertain to the common unbeaded can. After using the data to establish the empirical quantities in the models, good agreement was found between theory and experiment. the models were then used to predict strength characteristics of hypothetical cans.
METHODS to DISTINGUISH BETWEEN LAMINAR and VORTICAL FLOW IN SCRAPED SURFACE HEAT EXCHANGERS
Authors: HÄRRÖD MAGNUS 
Published: February 2007

ABSTRACTThe transition between laminar and vortical flow has been investigated in scraped surface heat exchangers (SSHEs), using new methods based on viscosity and temperature measurements.The transition occurred close to the critical Reynolds number for annular flow of Newtonian fluids. Thus, the methods used to predict the viscosity can be successfully applied to SSHEs despite the very complex flow behaviour of the products, the complex geometry of the SSHEs, and the heat transfer in the SSHEs.In industrial applications, the transition can be detected using the new method based on temperature measurements at the outlet of the SSHEs together with some calculations. This is a very important result, since with this “sensor” the flow pattern can be controlled towards the optimal flow pattern in SSHEs, which in turn is a fundamental requirement when the taste of aseptic products containing particulates are to be improved by the introduction of continuous sterilization.
NATURAL CONVECTION HEAT TRANSFER BETWEEN NON‐NEWTONIAN FLUIDS and an IRREGULAR SHAPED PARTICLE1
Authors: ALHAMDAN A. , SASTRY S.K. 
Published: February 2007

ABSTRACTNatural convection heat transfer was investigated between aqueous solutions of sodium carboxymethylcellulose (modeled as power law fluids) and a mushroom shaped particle, under transient conditions, with various initial temperature differences. Convective heat transfer coefficients (h) were observed to decrease over time due to thermal equilibration. the average value of h was significantly higher for heating (75 to 310 w/m2‐C) than for cooling (22 to 153 w/m2. C), and decreased with increasing viscosity (CMC concentration). For the lower viscosity ranges, h increased significantly with increasing initial temperature difference. Correlations were developed between Nusselt number and generalized Rayleigh and Fourier numbers.
AN APPROACH to STUDY and MODEL the HYDRODYNAMIC CLEANING EFFECT
Authors: BERGMAN BERT‐OVE , TRAGARDH CHRISTIAN 
Published: February 2007

ABSTRACTA sensor has been developed for continuous measurements of the removal of deposit. the sensor, which was based on heat transfer measurements, was also able to measure the wall shear stress.The device was used to study the mechanical effect during cleaning. It was found that the removal rate of deposits, at a surface, could be scaled by the mean wall shear stress. Measurements were performed under both laminar and turbulent flow conditions. the turbulent fluctuations did not influence the removal rate.
PARTICLE RESIDENCE TIME DISTRIBUTIONS IN A MODEL HORIZONTAL SCRAPED SURFACE HEAT EXCHANGER1
Authors: LEE JUN H. , SINGH RAKESH K. 
Published: February 2007

ABSTRACTResidence times and their distribution characteristics of potato cubes with aqueous solutions of sodium carboxymethyl cellulose (CMC), simulating non‐Newtonian fluid foods, in a horizontal scraped surface heat exchanger (SSHE) were investigated. Minimum and maximum normalized particle residence times (NPRTs) and standard deviations of mean values were not significantly affected by the particle concentration while mean NPRTs of up to 10% particle concentration were signficantly lower than those of 20–40% particle concentrations (P < 0.05). Mean NPRTs were significantly influenced by process parameters including concentration of carrier, viz., viscosity, mutator speed and particle size (P< 0.001) as well as 2‐way interactions among flow rate, mutator speed and particle size (P < 0.05 or 0.001). Furthermore, most of the individual particle residence time distributions in a horizontal SSHE flow could be described by either normal or gamma distribution models.
ELECTRICAL CONDUCTIVITIES of SELECTED SOLID FOODS DURING OHMIC HEATING1
Authors: PALANIAPPAN SEVUGAN , SASTRY SUDHIR K. 
Published: February 2007

ABSTRACTElectrical conductivities of three vegetable and two meat samples were determined by subjecting them to a constant voltage power supply in a static ohmic heating device. Conductivities of vegetable samples were increased by soaking them in salt solutions, while soaking in water resulted in reduced conductivity due to leaching of electrolytes. Conductivities under ohmic heating conditions increased linearly with temperature. When field strengths were decreased, the conductivity‐temperature curve gradually became nonlinear, and under conventional heating conditions, a sharp transition was observed.
MATHEMATICAL MODELING and EXPERIMENTAL STUDIES ON OHMIC HEATING of LIQUID‐PARTICLE MIXTURES IN A STATIC HEATER1
Authors: SASTRY SUDHIR K. , PALANIAPPAN SEVUGAN 
Published: February 2007

ABSTRACTUnderstanding of the ohmic heating of liquid‐particle mixtures requires preliminary study and model development within a static heater. A mathematical (3D finite element) model was developed for prediction of temperatures of mixtures of liquids and multiple particles within a static heater. Experiments were conducted using cubic potato particles within sodium phosphate solutions, for various particle sizes, orientations, concentrations, and liquid conductivities. the mathematical model was found to yield satisfactory prediction of experimental trends. Critical parameters affecting the relative heating rates of particles and liquid were the conductivities of the two phases, and the volume fraction of each phase. Ohmic heating appears most promising with high‐solids concentration mixtures.
A MODEL FOR HEATING of LIQUID‐PARTICLE MIXTURES IN A CONTINUOUS FLOW OHMIC HEATER1
Authors: SASTRY SUDHIR K. 
Published: February 2007

ABSTRACTDesign of safe thermal processes in a continuous flow ohmic heater requires mathematical model development, since temperature monitoring of particles in continuous flow is not presently possible. A mathematical model previously developed and verified for a static heater was modified to predict temperatures of fluids and particles within a continuous heater with high particle concentration suspensions. Results for constant voltage simulations indicate that the presence of large populations of low electrical conductivity particles results in slow heating of the entire mixture rather than a single phase alone. In all these cases, particles tend to heat faster than the liquid. However, if isolated low‐conductivity particles enter the system, the danger of underprocessing exists; hence particle conductivity is a critical control point. Simulations also indicate the role played by residence time distribution and liquid‐particle heat transfer coefficients in the above cases.
CONCENTRATION OF ONION JUICE VOLATILES BY REVERSE OSMOSIS AND ITS EFFECTS ON SUPERCRITICAL CO2 EXTRACTION
Authors: NUSS JEFFREY S. , GUYER DANIEL E. , GAGE DOUGLAS A. 
Published: February 2007

ABSTRACTSupercritical carbon dioxide extraction of onion oil at moderate temperatures produces aproduct which is characteristic of the fresh flavor of onions. It was attempted to improve extraction efficiency by concentrating the onion juice by reverse osmosis prior to supercritical CO2 extraction. Reverse osmosis was carried out for all combinations of 600, 700, and 800 psi feed pressure and 25 and 35C. The juice was concentrated to 18 oBtix and then subjected to supercritical CO2 extraction. The effect of concentration on the extraction process was evaluated by comparing the yields of extracts from concentrated juice with that of single strength juice. Concentration of onion juice by reverse osmosis improved the efficiency of supercritical CO2 extraction of onion oil and did not alter its characteristic fresh aroma.