scholarly journals Model of the solutes transfer during osmotic dehydration of vegetal matrices: a proposal

2018 ◽  
Author(s):  
Lilia Leticia Méndez-Lagunas ◽  
Sahylin Muñiz-Becerá ◽  
Juan Rodríguez-Ramírez ◽  
Sadoth Sandoval-Torres
Keyword(s):  
Reynolds Number ◽  
Layer Thickness ◽  
Osmotic Dehydration ◽  
Bulk Flow ◽  
Mathematical Writing ◽  
Schmidt Numbers ◽  
Convective Resistance ◽  
C 30 ◽  
C 50 ◽  
And Diffusion

Osmotic dehydration of apple was modeled considering the mechanisms involved in the solutes transfer within the plant matrix: impregnation and diffusion. The model mathematical writing includes the impregnation layer thickness, the diffusion thickness, a water bulk flow and the convective resistance. Apple cylinders were dehydrated at 30, 50 ° C and 30, 50 ° Brix and a motion of 0.15 m/s. The Reynolds number was of 250 for 30°C-30°Bx and 500 for 50°C-50°Bx. Schmidt numbers was of 4000 for 30 ° C-30 ° Bx and 4200 for 50 ° C-50 ° Bx.Keywords: transfer; solute; impregnation; osmotic dehydration. 

Annulus Wall Boundary-Layer Measurements in a Four-Stage Compressor

1986 ◽  
Vol 108 (1) ◽  
pp. 2-6 ◽  
Author(s):  
N. A. Cumpsty
Keyword(s):  
Boundary Layer ◽  
Reynolds Number ◽  
Layer Thickness ◽  
Boundary Layers ◽  
Boundary Layer Thickness ◽  
Tip Clearance ◽  
The Other ◽  
Wall Boundary Layer ◽  
Multistage Compressors ◽  
Full Design

There are few available measurements of the boundary layers in multistage compressors when the repeating-stage condition is reached. These tests were performed in a small four-stage compressor; the flow was essentially incompressible and the Reynolds number based on blade chord was about 5 • 104. Two series of tests were performed; in one series the full design number of blades were installed, in the other series half the blades were removed to reduce the solidity and double the staggered spacing. Initially it was wished to examine the hypothesis proposed by Smith [1] that staggered spacing is a particularly important scaling parameter for boundary layer thickness; the results of these tests and those of Hunter and Cumpsty [2] tend to suggest that it is tip clearance which is most potent in determining boundary-layer integral thicknesses. The integral thicknesses agree quite well with those published by Smith.

scholarly journals Impact of Sediment Layer on Longitudinal Dispersion in Sewer Systems

Water ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 3168
Author(s):  
Marek Sokáč ◽  
Yvetta Velísková
Keyword(s):  
Reynolds Number ◽  
Layer Thickness ◽  
Dispersion Coefficient ◽  
Longitudinal Dispersion ◽  
Low Flow ◽  
Pipe Diameter ◽  
Sediment Layer ◽  
Pollution Transport ◽  
Sewer Pipes ◽  
Hydraulic Conditions

Experiments focused on pollution transport and dispersion phenomena in conditions of low flow (low water depth and velocities) in sewers with bed sediment and deposits are presented. Such conditions occur very often in sewer pipes during dry weather flows. Experiments were performed in laboratory conditions. To simulate real hydraulic conditions in sewer pipes, sand of fraction 0.6–1.2 mm was placed on the bottom of the pipe. In total, we performed 23 experiments with 4 different thicknesses of sand sediment layers. The first scenario is without sediment, the second is with sediment filling 3.4% of the pipe diameter (sediment layer thickness = 8.5 mm), the third scenario represents sediment filling 10% of the pipe diameter (sediment layer thickness = 25 mm) and sediment fills 14% of the pipe diameter (sediment layer thickness = 35 mm) in the last scenario. For each thickness of the sediment layer, a set of tracer experiments with different flow rates was performed. The discharge ranges were from (0.14–2.5)·10−3 m3·s−1, corresponding to the range of Reynolds number 500–18,000. Results show that in the hydraulic conditions of a circular sewer pipe with the occurrence of sediment and deposits, the value of the longitudinal dispersion coefficient Dx decreases almost linearly with decrease of the flow rate (also with Reynolds number) to a certain limit (inflexion point), which is individual for each particular sediment thickness. Below this limit the value of the dispersion coefficient starts to rise again, together with increasing asymmetricity of the concentration distribution in time, caused by transient (dead) storage zones.

Urea transport across dog intestinal mucosa in vitro

1964 ◽  
Vol 206 (6) ◽  
pp. 1315-1320 ◽  
Author(s):  
A. A. Hakim ◽  
Nathan Lifson
Keyword(s):  
Small Intestine ◽  
Water Transport ◽  
Water Flow ◽  
Intestinal Mucosa ◽  
Bulk Flow ◽  
Urea Transport ◽  
The Relationship ◽  
And Diffusion ◽  
Isotopic Water

Mucosal membranes from the small intestine of the dog were stripped and mounted for study between two bathing fluids, as previously described. The relationship between urea and water transport, including uphill movement of urea in the direction of water flow, was that expected from a combination of bulk flow and diffusion. If sieving was present, it was minor. Results for downhill movement of D2O, the isotopic water treated as a solute, were comparable to those for urea.

Effect of separated layer thickness on magnetoresistance and magnetic properties of Co/Dy/Co and Ni/Dy/Ni film systems

2018 ◽  
Vol 32 (01) ◽  
pp. 1750275 ◽  
Author(s):  
T. M. Shabelnyk ◽  
O. V. Shutylieva ◽  
S. I. Vorobiov ◽  
I. M. Pazukha ◽  
A. M. Chornous
Keyword(s):  
Magnetic Properties ◽  
Layer Thickness ◽  
Phase State ◽  
Diffusion Processes ◽  
Hysteresis Loops ◽  
Before And After ◽  
Beam Sputtering ◽  
Diffraction Patterns ◽  
20 Nm ◽  
And Diffusion

Co(5 nm)/Dy(t[Formula: see text])/Co(20 nm)/S and Ni(5 nm)/Dy(t[Formula: see text])/Ni(20 nm)/S trilayer films are prepared by electron-beam sputtering to investigate the influence of dysprosium layer thickness (t[Formula: see text]) and thermal annealing on the crystal structure, magnetoresistance (MR) and magnetic properties of thin films. The thickness of Dy layer changed in the range from 1 nm to 20 nm. The samples annealed for 20 min at 700 K. Electron diffraction patterns reveal that the as-deposited and annealed systems Co/Dy/Co and Ni/Dy/Ni had fcc-Co + hcp-Dy and fcc-Ni + hcp-Dy phase state, respectively. It is also shown that at the t[Formula: see text] = 15 nm the transition from amorphous to crystalline structures of Dy layer is observed. An increase in the Dy layer thickness results in changes in the MR and magnetic properties of the trilayer systems. It is shown that MR is most thermally stable against annealing to 700 K at t[Formula: see text] = 15 nm for Co/Dy/Co as well as for Ni/Dy/Ni. For t[Formula: see text] = 15 nm the, value of MR for both system increases by two times compared to those of pure ferromagnetic (FM) samples. The coercivity (B[Formula: see text]), remanent (M[Formula: see text]) and saturation (M[Formula: see text]) magnetization of the in-plain magnetization hysteresis loops are related to the Dy layer thickness too. The coercivity depends on the FM materials type and diffusion processes at the layer boundary. Accordingly, M[Formula: see text] and M[Formula: see text] are reduced with t[Formula: see text] increasing before and after annealing for both trilayer systems.

scholarly journals Muscle fatigue examined at different temperatures in experiments on intact mammalian (rat) muscle fibers

2009 ◽  
Vol 106 (2) ◽  
pp. 378-384 ◽  
Author(s):  
H. Roots ◽  
G. Ball ◽  
J. Talbot-Ponsonby ◽  
M. King ◽  
K. McBeath ◽  
...  
Keyword(s):  
Muscle Fatigue ◽  
Power Output ◽  
Force Depression ◽  
Output Force ◽  
Different Temperatures ◽  
Force Velocity ◽  
C 30 ◽  
C 50 ◽  
Shortening Contractions

In experiments on small bundles of intact fibers from a rat fast muscle, in vitro, we examined the decline in force in repeated tetanic contractions; the aim was to characterize the effect of shortening and of temperature on the initial phase of muscle fatigue. Short tetanic contractions were elicited at a control repetition rate of 1/60 s, and fatigue was induced by raising the rate to 1/5 s for 2–3 min, both in isometric mode (no shortening) and in shortening mode, in which each tetanic contraction included a ramp shortening at a standard velocity. In experiments at 20°C ( n = 12), the force decline during a fatigue run was 25% in the isometric mode but was significantly higher (35%) in the shortening mode. In experiments at different temperatures (10–30°C, n = 11), the tetanic frequency and duration were adjusted as appropriate, and for shortening mode, the velocity was adjusted for maximum power output. In isometric mode, fatigue of force was significantly less at 30°C (∼20%) than at 10°C (∼30%); the power output (force × velocity) was >10× higher at 30°C than at 10°C, and power decline during a fatigue run was less at 30°C (∼20–30%) than at 10°C (∼50%). The finding that the extent of fatigue is increased with shortening contractions and is lower at higher temperatures is consistent with the view that force depression by inorganic phosphate, which accumulates within fibers during activity, may be a primary cause of initial muscle fatigue.

scholarly journals Fruit dragée formulated with reused solution from pineapple osmotic dehydration

2017 ◽  
Vol 52 (9) ◽  
pp. 806-813
Author(s):  
Sílvia Pimentel Marconi Germer ◽  
Gisele Marcondes Luz ◽  
Lidiane Bataglia da Silva ◽  
Marta Gomes da Silva ◽  
Marcelo Antonio Morgano ◽  
...  
Keyword(s):  
Vitamin C ◽  
Purchase Intention ◽  
Osmotic Dehydration ◽  
Microbial Load ◽  
Ananas Comosus ◽  
Solution Properties ◽  
Sensory Acceptance ◽  
Osmotic Solution ◽  
C 30

Abstract: The objective of this work was to evaluate the reuse of sucrose syrup in pineapple (Ananas comosus) osmotic dehydration and the application of the spent solution in fruit dragée formulation. Osmotic dehydration trials were performed in five cycles (65° Brix/45°C/3 hours), directly reusing the osmotic solution, with only one intermediate reconditioning step. Variations in osmotic solution properties and in dehydration parameters were observed, as well as a low microbial load in the system. The spent solution was rich in vitamin C (30 mg 100 g-1). Pineapple dragée covered with red fruits and acai powders were obtained with the reconditioned spent solution used as an adhesion solution. The dragée presented high levels of vitamin C (176 mg 100 g-1), polyphenols (154 mg GAE 100-1 g), carotenoids (220 μg 100 g-1), and potassium (330 mg 100 g-1). The product showed good sensory acceptance and purchase intention. Reusing sucrose syrup is technically feasible during pineapple osmotic dehydration, as is the application of the spent solution as an ingredient in fruit dragée production.

scholarly journals Theoretical description of the ligand function for ionoselective electrodes reversible to metal anion complexes. 1. Lower detection limit and its determining factors

2020 ◽  
pp. 17-28
Author(s):  
Vladimir V. Egorov ◽  
Andrei V. Semenov ◽  
Andrei D. Novakovskii ◽  
Yauhen B. Akayeu
Keyword(s):  
Detection Limit ◽  
Layer Thickness ◽  
Diffusion Layer ◽  
Theoretical Description ◽  
Diffusion Layer Thickness ◽  
Thiocyanate Ion ◽  
Lower Detection Limit ◽  
Diffusion Parameters ◽  
Lower Detection ◽  
And Diffusion

Within the framework of the steady-state diffusion model, the theoretical description for the thiocyanate ion lower detection limit (LDL) by the tetrathiocyanatozincate selective electrode, has been presented. The main assumptions of this model are constancy of the ion exchanger concentration along the membrane, traditionally used in various phaseboundary potential diffusion models, and linear profiles of components’ concentrations in diffusion layers. Simple quantitative expressions have been obtained, connecting thiocyanate ion concentration in the solution surface layer (responsible for LDL value) with phase boundary extraction equilibria constants, stability constants for zinc thiocyanate complexes, and diffusion parameters in the membrane and solution phases. Calculated LDL values are in good agreement with experimental data provided in the literature. It has been shown that LDL can be reduced substantially by controlling such easily regulated diffusion parameters as diffusion layer thickness in the membrane phase, which is a function of time, and diffusion layer thickness of the sample solution, which is governed by stirring regime.

scholarly journals Estimasi Persentase Karbon Organik Di Hutan Mangrove Bekas Tambak, Perancak, Jembrana, Bali

2015 ◽  
Vol 1 (1) ◽  
pp. 14 ◽  
Author(s):  
I Gusti Agung Indah Mahasani ◽  
Nuryani Widagti ◽  
I Wayan Gede Astawa Karang
Keyword(s):  
Organic Carbon ◽  
Mangrove Forest ◽  
Mangrove Forests ◽  
Loss On Ignition ◽  
Vertical Variation ◽  
Average Percentage ◽  
Vertical Variations ◽  
C 30 ◽  
C 50 ◽  
Carbon Dioxide Co2

Mangrove forests in the coastal regions are very effective and efficient in reducing the concentration carbon dioxide (CO2) in the atmosphere, because mangroves can absorb CO2 through photosynthesis by diffusion through the stomata and then store carbon in the form of biomass. The purpose of this study, namely: (1) Determine the percentage of organic carbon in the soil in former mangrove forest ponds in Perancak and (2) Determine the vertical variation of the percentage of organic carbon stored in soils in former mangrove forest ponds in Perancak. The method used from this study is the loss on ignition (LOI). The average percentage of organic carbon in mangrove forest area of the former farm of 50.181 % C or 184.618 Mg/ha. The average vertical variations of each depth, that is: depth (0-15 cm) 50.487 % C, (15- 30 cm) 50.781 % C, (30-50 cm) 50.550 % C, (50- 100 cm) 51.689 % C, and (> 100 cm) 47.396 % C.

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