Simulation of Time-Dependent Wellbore Stability in Shales Using A Coupled Mechanical-Thermal-Physico-Chemical Model

2003 ◽  
Author(s):  
R. Freij-Ayoub ◽  
C.P. Tan ◽  
S.K. Choi
Keyword(s):  
Wellbore Stability ◽  
Time Dependent ◽  
Chemical Model ◽  
Physico Chemical

scholarly journals Time-Dependent Changes in the Physico-Chemical Parameters and Growth Responses of Sedum acre (L.) to Waste-Based Growing Substrates in Simulation Extensive Green Roof Experiment

Agronomy ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 298
Author(s):  
Anna Krawczyk ◽  
Iwona Domagała-Świątkiewicz ◽  
Agnieszka Lis-Krzyścin
Keyword(s):  
Green Roof ◽  
Matter Content ◽  
Time Dependent ◽  
First Year ◽  
Chemical Parameters ◽  
Growing Media ◽  
Extensive Green Roof ◽  
Physico Chemical ◽  
Commercial Medium ◽  
Sedum Acre

Over the last decade, an increase in the use of locally available, recycled, and waste materials as growing media components have occurred in various regions of the world in extensive green roof technology. For eco-concept reasons, such a strategy appears to be appropriate, but can be problematic due to difficulties in obtaining proper parameters of growing substrate. The growing media should be properly engineered in order to enable the proper functioning of green roofs and provide suitable environment for ideal root growth. The aim of the study was to assess the utility of locally occurring waste materials for growing media composition and estimate plant- and time-dependent changes in the physico-chemical parameters of waste-based substrates in a simulated extensive green roof system during a two-year Sedum acre L. cultivation. Five different substrate compositions were prepared using silica waste, crushed brick, Ca- and Zn-aggregates, melaphyre, tuff, sand, muck soil, urban compost, spent mushroom, and coconut fibres. Optimal water capacity, particle-size distribution, pH and salts concentration were found in all substrates. A higher concentration of macronutrients (N, P, K, Mg) and trace elements (B, Cu, Fe, Mn, Zn, Cd, Ni, Pb, and Cr) was found in waste-based substrates than in the commercial medium. In comparison to the parameters determined before establish the experiment, bulk density of tested growing media decreased, except for the substrates where the source of organic matter was the rapidly mineralising spent mushroom. The organic matter content in substrates after the two-year vegetation increased in relation to the ready-made substrate, with the exception of the composition with spent mushroom. After two years of the experiment, all available macronutrients and trace elements (with the exception of mineral N, K, SO4-S, and B) concentration were higher than in 2014, while pH, salt concentration was lower. In general, plants grown in waste substrates had lower dry matter content and higher biomass. A significantly higher biomass of S. acre L. was found in the first year of the experiment. In the second year of the research, the plants grown in the commercial medium, the substrate with silica waste, and the substrate with spent mushroom produced higher biomass than in the first year. No symptoms of abnormal growth were observed, despite the higher trace element concentrations in plants collected from waste-based substrate. Waste-based growing media can be considered as a valuable root environment for S. acre L. in an extensive green roof system.

scholarly journals An improved physico-chemical model of hybridization on high-density oligonucleotide microarrays

2008 ◽  
Vol 24 (10) ◽  
pp. 1278-1285 ◽  
Author(s):  
N. Ono ◽  
S. Suzuki ◽  
C. Furusawa ◽  
T. Agata ◽  
A. Kashiwagi ◽  
...  
Keyword(s):  
High Density ◽  
Chemical Model ◽  
Oligonucleotide Microarrays ◽  
Physico Chemical

scholarly journals Influence of galactic arm scale dynamics on the molecular composition of the cold and dense ISM III. Elemental depletion and shortcomings of the current physico-chemical models

2020 ◽  
Vol 497 (2) ◽  
pp. 2309-2319
Author(s):  
V Wakelam ◽  
W Iqbal ◽  
J-P Melisse ◽  
P Gratier ◽  
M Ruaud ◽  
...  
Keyword(s):  
Gas Phase ◽  
Molecular Form ◽  
Dense Medium ◽  
Chemical Model ◽  
Physical Conditions ◽  
Dense Cores ◽  
Chemical Models ◽  
Physico Chemical ◽  
Galactic Model ◽  
Elemental Depletion

ABSTRACT We present a study of the elemental depletion in the interstellar medium. We combined the results of a Galactic model describing the gas physical conditions during the formation of dense cores with a full-gas-grain chemical model. During the transition between diffuse and dense medium, the reservoirs of elements, initially atomic in the gas, are gradually depleted on dust grains (with a phase of neutralization for those which are ions). This process becomes efficient when the density is larger than 100 cm−3. If the dense material goes back into diffuse conditions, these elements are brought back in the gas phase because of photo-dissociations of the molecules on the ices, followed by thermal desorption from the grains. Nothing remains on the grains for densities below 10 cm−3 or in the gas phase in a molecular form. One exception is chlorine, which is efficiently converted at low density. Our current gas–grain chemical model is not able to reproduce the depletion of atoms observed in the diffuse medium except for Cl, which gas abundance follows the observed one in medium with densities smaller than 10 cm−3. This is an indication that crucial processes (involving maybe chemisorption and/or ice irradiation profoundly modifying the nature of the ices) are missing.

A physico-chemical model for polyelectrolyte enhanced ultrafiltration

2011 ◽  
Vol 376 (1-2) ◽  
pp. 142-152 ◽  
Author(s):  
Sourav Mondal ◽  
Sonia Ben Mlouka ◽  
Mahmoud Dhahbi ◽  
Sirshendu De
Keyword(s):  
Chemical Model ◽  
Physico Chemical

scholarly journals Distinct and Quantitative Validation for Predictive Process Modelling in Steam Distillation of Caraway Fruits and Lavender Flower Following a Quality-By-Design (QbD) Approach

Processes ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 594 ◽  
Author(s):  
Thorsten Roth ◽  
Lukas Uhlenbrock ◽  
Jochen Strube
Keyword(s):  
Quality By Design ◽  
Steam Distillation ◽  
Process Development ◽  
Model Development ◽  
Chemical Model ◽  
Maximum Information ◽  
Physico Chemical ◽  
Target Values ◽  
Different Types ◽  
Quantitative Validation

A quality by design (QbD) approach as part of process development in the regulated, pharmaceutical industry requires many experiments. Due to the large number, process development is time consuming and cost intensive. A key to modern process development to reduce the number of required experiments is a predictive simulation with a validated physico-chemical model. In order to expand the process expertise of steam distillation through maximum information, a model development workflow is used in this paper, which focuses on implementation, verification, parametrization and validation of a physico-chemical model. Process robustness and sensitivity of target values can be determined from the developed general model and design of experiments with statistical evaluations. The model validation is exemplified by two different types of plant systems, caraway fruits (Carum Carvi) and lavender flowers (Lavandula).

scholarly journals A Physico-chemical Model of Seepage Flows in Reservoirs during Alkaline Flooding

2011 ◽  
Author(s):  
Z. Zhang ◽  
J. C. Li ◽  
Jiachun Li ◽  
Song Fu
Keyword(s):  
Chemical Model ◽  
Seepage Flows ◽  
Physico Chemical

Applications of time-dependent pseudo-3D stress analysis in evaluating wellbore stability

1997 ◽  
Vol 34 (3-4) ◽  
pp. 1.e1-1.e16 ◽  
Author(s):  
Y. Abousleiman ◽  
L. Cui ◽  
S. Ekbote ◽  
M. Zaman ◽  
J.-C. Roegiers ◽  
...  
Keyword(s):  
Stress Analysis ◽  
Wellbore Stability ◽  
Time Dependent
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