Quality of samples retrieved from great depth and its influence on consolidation properties

2002 ◽  
Vol 39 (6) ◽  
pp. 1288-1301 ◽  
Author(s):  
Hiroyuki Tanaka ◽  
Fusao Ritoh ◽  
Naoki Omukai
Keyword(s):  
Void Ratio ◽  
Volumetric Strain ◽  
Great Depth ◽  
Sampling Depth ◽  
Osaka Bay ◽  
Oedometer Test ◽  
Preconsolidation Pressure ◽  
Constant Rate ◽  
Sample Disturbance

Pleistocene sediments deposited in Osaka Bay have been extensively investigated to depths of up to 400 m. Consolidation properties, especially preconsolidation pressure, are somewhat scattered with depth. The quality of samples retrieved from great depths has been evaluated based on the indices calculated from the volumetric strain or the void ratio changes in the recompression process. The study reveals that these indices do not simply increase with an increase in sampling depth. The potential for sample disturbance during sample setting in the constant rate of strain (CRS) oedometer was also investigated. These tests have revealed that the preconsolidation pressure, as measured in the laboratory, is not influenced significantly by swelling. In addition, preconsolidation pressures indicate that the sediments are slightly overconsolidated, with a departure from normally consolidated behaviour that could be explained by cementation.Key words: sampling, preconsolidation pressure, sample disturbance, oedometer test, Pleistocene clay, great depth.

scholarly journals Laboratory and field determination of preconsolidation pressures at Gloucester

1983 ◽  
Vol 20 (3) ◽  
pp. 477-490 ◽  
Author(s):  
S. Leroueil ◽  
L. Samson ◽  
M. Bozozuk
Keyword(s):  
Test Site ◽  
Test Methods ◽  
Strain Rate Effects ◽  
Oedometer Test ◽  
Undisturbed Samples ◽  
Preconsolidation Pressure ◽  
Constant Rate ◽  
Rate Effects

In recent literature several special test methods have been proposed to measure the preconsolidation pressure of a compressible clay soil. Five methods, in addition to the conventional oedometer test, were applied to the marine clays from the Gloucester test site. The preconsolidation pressures measured using these laboratory tests were compared with that mobilized in situ below the centre of a test embankment. The investigation showed that the preconsolidation pressure is directly related to the rate of strain and that special techniques such as constant rate of strain, controlled gradient, single-stage loading, and anisotropic triaxial consolidation tend to overestimate the in-situ preconsolidation pressure. The conventional oedometer test using a load increment ratio of 0.5 and a reloading schedule of 24 h applied to good-quality undisturbed samples produced preconsolidation pressures that compared best with the in-situ values. Keywords: preconsolidation pressure, laboratory, in situ, strain rate effects, disturbance.

Studies to Evaluate the Safety of Constant Rate Infusions of Dexmedetomidine, Ketamine and Lidocaine Alone or in Combination during Isoflurane Anesthesia in Horses

2021 ◽  
Author(s):  
Aswathy Gopinathan ◽  
Kiranjeet Singh ◽  
Sherin B. Sarangom ◽  
V. Ramya ◽  
P. Sangeetha ◽  
...  
Keyword(s):  
Significant Decline ◽  
Constant Rate Infusion ◽  
Anesthetic Depth ◽  
Isoflurane Anesthesia ◽  
Anesthetic Agents ◽  
Constant Rate ◽  
Sparing Effect ◽  
Rate Infusion ◽  
Operative Quality

Background: Horses mount a huge stress response to anesthesia when compared to other animals, hence are risky candidates for anesthesia. Inhalant anesthetic agents offer more control to anesthetic depth and facilitate rapid recovery, hence are considered to be safer than intravenous agents for surgical procedures requiring more than an hour, however, newer drug combinations are being explored to minimize the undesired consequences and dose rate of inhalant agents. The present study explored the safety of dexmedetomidine, ketamine and lidocaine constant rate infusion alone or as a combination along with Isoflurane for safer anesthesia in horses.Methods: The study was conducted on 28 horses divided into S, D, DK and DKL groups having 7 animals in each. Xylazine (1 mg/kg) and butorphanol (0.05mg/kg) were given intravenously for premedication. Ketamine (2 mg/kg) and midazolam (0.2 mg/kg) were used for induction and anesthesia was maintained with isoflurane. Normal saline (1000ml/hour), Dexmedetomidine (2µg/kg/hr), Dexmedetomidine and ketamine (2 µg/kg/hr and 2 mg/kg/hr) and Dexmedetomidine, ketamine and lidocaine (2 µg/kg/hr, 2 mg/kg/hr and 2 mg/kg/h) were given as CRI in groups S, D, DK and DKL, respectively. Thiopentone sodium (250mg bolus, 5%) was given as a fast intravenous bolus whenever required. Anesthetic efficacy was evaluated based on clinical, haemato-biochemical, hemodynamic, and endocrine variables.Result: A significant decline in mean arterial pressure was noticed in group DKL but changes in CVP and SpO2 in different groups were non-significant. Higher Blood glucose and low Insulin levels were seen in group DK during 45-60 min. Constant rate infusions of Dexmedetomidine, Ketamine and Lidocaine alone or in combination produced a significant sparing effect on Isoflurane and thiopentone while they improved peri-operative quality of anesthesia in horses.

The Quality of U100 Sampling

1986 ◽  
Vol 2 (1) ◽  
pp. 419-423
Author(s):  
I. L. Whyte
Keyword(s):  
Particle Size ◽  
Moisture Content ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
General Purpose ◽  
Volume Changes ◽  
Sample Quality ◽  
Class 1 ◽  
Sample Disturbance

AbstractThe origins and development of the U100 (U4) thick-walled open-drive sampler are reviewed. The requirements of CP 2001 and BS 5930 are examined in relation to sample quality, and these are shown to be too favourable. Causes of sample disturbance are considered, particularly those due to volume changes, and shown to depend on moisture content, plasticity and particle size distribution. Quality classes possible with conventional U100 samples are suggested, and Classes 3 or 4 are to be generally expected. Class 1 samples are improbable. It is recommended that a general purpose sampler such as the U100 should have a maximum inside clearance of 1% and not ‘about 1%’ as recommended in BS 5930.

scholarly journals Ozonated water in the post-harvest treatment of coffee fruits

2016 ◽  
Vol 20 (9) ◽  
pp. 862-866 ◽  
Author(s):  
Fernando J. B. Brandão ◽  
Marco A. M. Biaggioni ◽  
Felipe C. S. Sperotto ◽  
Erika Fujita ◽  
Paula L. Santos ◽  
...  
Keyword(s):  
Sensory Quality ◽  
Reducing Sugars ◽  
Water System ◽  
Quality Analysis ◽  
Partial Reduction ◽  
Negative Results ◽  
Constant Rate ◽  
Recirculating Water System ◽  
Ozonated Water

ABSTRACT Ozone is used in many countries for the treatment of effluents, becoming a viable alternative in sanitation of coffee wastewater. However, the strong ozone oxidation, responsible for its germicidal effect, can also compromise grain and beverage quality. The objective of this study was to evaluate the quality of Arabica coffee in different periods of treatment with ozonated water and its effect after drying. Coffee fruits were subjected to ozonation at regular intervals of 0, 5, 10, 20, and 30 min, with continuous stirring promoted by a recirculating water system at constant rate of 1 ppm of solubilized ozone. The design was completely randomized with five treatments and four replicates. After obtaining the data, the analysis of variance was performed and means were compared by Tukey test (p ≤ 0.05). The results showed a partial reduction of fungi after washing with ozonated water, but the same effect was not observed after drying. For coffee quality analysis, the longest times of exposure to the solubilized gas in the water produced some negative results in electrical conductivity and total and reducing sugars. However, the sensory quality of the beverage was maintained.

scholarly journals Evolution of the soil water retention curve based on plastic volumetric strain

2020 ◽  
Vol 195 ◽  
pp. 02016
Author(s):  
J. Kodikara ◽  
C. Jayasundara
Keyword(s):  
Soil Water ◽  
Unsaturated Soils ◽  
Water Retention ◽  
Void Ratio ◽  
Volumetric Strain ◽  
Water Retention Curve ◽  
Soil Water Retention Curve ◽  
Soil Water Retention ◽  
Retention Curve ◽  
Plastic Volumetric Strain

The water retention behaviour of soil can be defined as the relationship between the degree of saturation (or water content) and suction at a constant temperature, which characterises the hydraulic behaviour of unsaturated soils, normally represented as the soil water retention curve (SWRC). The SWRC is commonly measured at nominal net stress by initially saturating a soil specimen and then subjecting it to drying and wetting paths, resulting in major drying and wetting curves. However, there is evidence that during these major drying and wetting paths and initial saturation, soil can undergo volumetric deformation with changes in void ratio, sometimes plastically. Therefore, for coupling the SWRC with mechanical behaviour, the dependency of SWRC on other state variables such as void ratio has been proposed. In this paper, an approach to defining SWRC for a particular plastic volumetric strain is presented within the generalised MPK model. The SWRC evolves as soil is subjected to wet/dry cycles, eventually approaching drying and wetting curves relevant to an environmentally-stabilised state. The performance of this model is demonstrated by the simulation of the loading/unloading/drying/wetting paths followed in a laboratory experiment. In addition, the evolution of the commonly-considered major drying and wetting curves is simulated, highlighting key features of the environmentally-stabilised line..

Interpretation of overconsolidation ratio from in situ tests in Recent clay deposits in Singapore and Malaysia

1991 ◽  
Vol 28 (2) ◽  
pp. 210-225 ◽  
Author(s):  
M. F. Chang
Keyword(s):  
Site Investigation ◽  
Test Methods ◽  
In Situ Tests ◽  
Stress History ◽  
Overconsolidation Ratio ◽  
Clay Deposits ◽  
Preconsolidation Pressure ◽  
Pressure Stress ◽  
Sample Disturbance

The stress history as indicated by the profile of overconsolidation ratio (OCR) of a soil deposit is one of the most dominant factors that influence the engineering behaviour of the soil. Its assessment, which is traditionally based on the laboratory oedometer test, is not often satisfactory. The problem arises from inevitable sample disturbance and the high cost of a detailed investigation. These difficulties can be overcome by the use of in situ tests. The field vane test, the piezocone test, and the dilatometer test are three such methods that provide indirect means for the estimation of the OCR for clay deposits. A number of empirical correlations are available for this purpose. Calibration of these correlations against results of site investigation in Singapore and Malaysian marine clays reveals the usefulness of these test methods in profiling the OCR for Recent clay deposits. Key words: clay, in situ test, overconsolidation ratio, preconsolidation pressure, stress history.

scholarly journals Method to Determine the Constitutive Permeability Parameters of Non-Linear Consolidation Models by Means of the Oedometer Test

Mathematics ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 2237
Author(s):  
Gonzalo García-Ros ◽  
Iván Alhama
Keyword(s):  
Inverse Problem ◽  
Hydraulic Conductivity ◽  
Void Ratio ◽  
Linear Models ◽  
Constitutive Relations ◽  
Laboratory Data ◽  
Permeability Index ◽  
Oedometer Test ◽  
Non Linear ◽  
Constitutive Parameters

This paper presents an easy-to-apply methodology that allows obtaining the permeability index and the initial hydraulic conductivity of clayey soils, basic constitutive parameters in non-linear models of consolidation, based on the laboratory oedometer test. For this, the data of the void ratio, compressibility index and characteristic consolidation time are taken from the test and, as an inverse problem, the constitutive permeability parameters sought are determined by applying the universal solutions of the characteristic time for a general non-linear consolidation model with constitutive relations void ratio-effective soil stress and hydraulic conductivity-void ratio of logarithmic type. The application protocol of the inverse problem is described in detail and illustrated by a series of applications carried out on real laboratory data belonging to two different soils. The influence that errors in laboratory parameter measurements can have on the final values of the permeability index and initial hydraulic conductivity is studied, showing the maximum deviations that may appear and, by last, the precision of the results obtained.

scholarly journals Effects of low temperature drying processing on longan fruit

2018 ◽  
Vol 192 ◽  
pp. 03024
Author(s):  
Thadchapong Pongsuttiyakorn ◽  
Pachareeporn trusphimai ◽  
Pitikhate Sooraksa ◽  
Pimpen Pornchaloempong
Keyword(s):  
Drying Rate ◽  
Suitable Model ◽  
Moisture Removal ◽  
Browning Index ◽  
Air Temperatures ◽  
Constant Rate ◽  
Drying Techniques ◽  
Rate Period ◽  
Low Temperature Drying

In this study, the single-stage drying in tray dryer at air temperatures of 40, 50, 60, 70 and 80°C is modelled and investigated. The longan fruits, E-dor variety, are peeled and seeded before testing. The drying rate is significantly influenced by the drying techniques and temperatures. Drying rats are initialized adjustment constant rate periods at 60 70 and 80°C. The rate of moisture removal is rapidly changed drastically during the falling rate period. The Midilli model with high R2 and low χ2 and RMSE is the most suitable model for predictability of longan drying. Variation rates of quality of the water activity, the shrinkage, and the browning index are also reported.

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