A modified approach for determination of nonlinear properties in seismic response analyses for 200 m high core rock-fill dams

2008 ◽  
Vol 45 (8) ◽  
pp. 1064-1072 ◽  
Author(s):  
Hongjun Li ◽  
Shichun Chi ◽  
Gao Lin ◽  
Hong Zhong
Keyword(s):  
Site Response ◽  
Confining Pressure ◽  
In Situ Stress ◽  
Nonlinear Properties ◽  
Rock Fill ◽  
Equivalent Linear ◽  
Wide Range ◽  
Confining Pressures ◽  
The Impact

Equivalent linear analyses are widely used for estimation of site response and safety status of rock-fill dams subjected to strong earthquakes. However, the average normalized curves incorporated in the equivalent-linear iterative process cannot precisely depict the variations of dynamic parameters with shearing strain for one type of soil material under a wide range of confining pressures. Thus, a modified approach for the determination of nonlinear properties for soil elements confined under a broad range of effective pressures in site response analyses for high rock-fill dams (>200 m) is proposed. In this approach, the normalized confining-pressure-interpolating curves (CPI curves) of each soil element under different effective stress are obtained by linearly interpolating or extrapolating by its in situ stress. By comparing the results obtained by equivalent linear analyses incorporating the average curves and the CPI curves, respectively, the impact of utilizing the recommended curves when determining nonlinear soil properties on site response analyses of high rock-fill dams (>200 m) is discussed. It is shown that the refinement in the determination of nonlinear properties during site response can be utilized in the near future by incorporating the results of this study in practice.

scholarly journals Study on the impact of confining pressure on gas permeability of tight sandstone cores

2021 ◽  
Vol 2076 (1) ◽  
pp. 012006
Author(s):  
Jianxiang Tong ◽  
Hengyang Wang ◽  
Yuyi Wang ◽  
Ya Zhang ◽  
Xiaohe Huang
Keyword(s):  
Power Function ◽  
Rate Coefficient ◽  
Gas Permeability ◽  
Confining Pressure ◽  
Experimental Sample ◽  
Tight Sandstone ◽  
Change Rate ◽  
Shengli Oilfield ◽  
Confining Pressures ◽  
The Impact

Abstract Taking the tight sandstone core of Shengli Oilfield as the experimental sample, this paper studies the permeability variation of the tight sandstone under different confining pressures. The experimental results show that when the pore pressure is constant, the measured gas permeability of core decreases with the increase of confining pressure. Power function is more reasonable to describe the influence of confining pressure on permeability of tight sandstone between power function and exponential function. Analyze the impact of confining pressure on gas permeability of tight sandstone cores by using permeability change rate coefficient D and coefficient S.

scholarly journals Determination of sources of sulfur dioxide in confectionery

2019 ◽  
Vol 80 (4) ◽  
pp. 203-208
Author(s):  
N. B. Kondratyev ◽  
E. V. Kazantsev ◽  
M. V. Osipov ◽  
O. S. Rudenko ◽  
E. N. Krylova
Keyword(s):  
Sulfur Dioxide ◽  
Raw Materials ◽  
Customs Union ◽  
White Sand ◽  
Wide Range ◽  
Confectionery Products ◽  
Definition Of ◽  
The Impact ◽  
Technological Methods

Sulfur dioxide is used to ensure the safety of fruit raw materials and semi-finished products used for the production of confectionery. This preservative has allergenic properties. In accordance with the Technical Regulations of the Customs Union TR CU 022/2011 "Food products in terms of their labeling" the content of sulfur dioxide must be specified when labeling confectionery products, if its content exceeds 10 mg per kg. The definition of this preservative in raw materials, semi-finished products and confectionery in accordance with the current GOST 26811 “Confectionery. The iodometric method for determining the mass fraction of total sulfuric acid is often difficult because of the complexity of confectionery products, the formation of intensive staining of the solutions under study and the ability of sulfur dioxide to react with other components of the objects under study. Therefore, the task of developing methods with the optimization of the sample preparation stage of the samples under study, which allow one to fully determine sulfur dioxide in confectionery products, semi-finished products and raw materials, is relevant. The purpose of this work was to develop methods for determining sulfur dioxide in raw materials, semi-finished products and various names of confectionery products, as well as assessing the impact of these types of raw materials and semi-finished products on the content of sulfur dioxide in confectionery products. The results showed that sulfur dioxide is present in many raw materials. In mg per 1 kg of sugar in white sand from 1 to 9, molasses from 25 to 52, wheat flour from 9 to 15, starch from 3 to 17. In fruit raw materials from 5 to 545 mg per kg. In confectionery: marshmallow and marshmallow from 8 to 29, gingerbread from 6 to 25, biscuits from 0 to 16, chocolate from 8 to 13. Based on the data obtained, it can be concluded that the content of sulfur dioxide in raw materials and semi-finished confectionery products is a very wide range, which makes it necessary to control the quality of all raw materials entering the production. Sulfur dioxide, used as a preservative for fruit raw materials, can significantly increase the content of this allergen in confectionery made using such raw materials. Ensuring the level of sulfur dioxide less than 10 mg / kg is achieved using raw materials with low content of sulfur dioxide and technological methods.

Experimental and Numerical Investigation of the Influence of Cutting Speed and Feed Rate on Forces in Turning of Steel

2016 ◽  
Vol 862 ◽  
pp. 270-277 ◽  
Author(s):  
János Kundrák ◽  
Gergely Szabó ◽  
Angelos P. Markopoulos
Keyword(s):  
Finite Elements ◽  
Feed Rate ◽  
Cutting Speed ◽  
Cutting Conditions ◽  
Strain Rates ◽  
Wide Range ◽  
Speed Range ◽  
The Impact ◽  
Cutting Speeds

The impact of cutting speeds and feed rates on the components of the forces exerted on a 16MnCr5 steel workpiece is experimentally measured, when turning with PCBN tool. The cutting speed range of the tests varies between 90 to 240 m/min while the feed rate is between 0.05 and 0.25 mm/rev for each cutting speed, allowing for the determination of the influence of cutting conditions on forces. Additionally, finite elements models for the simulation of the aforementioned experiments are provided. The proposed models exhibit good correlation of their results on cutting forces and chip formation with the measurements and observations of the experiments. Furthermore, the models can provide a wide range of additional parameters, i.e. plastic strain rates and temperatures within the workpiece. Results of the presented analysis can be used for an efficient process planning for the turning of steels under cutting conditions used in the industry.

scholarly journals A parametric study on cyclic strength of coastal sand of Digha in West Bengal, India

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Pinak Ray ◽  
Ramendu Bikas Sahu
Keyword(s):  
West Bengal ◽  
Confining Pressure ◽  
Cyclic Stress ◽  
Cyclic Strength ◽  
Triaxial Tests ◽  
Cyclic Stress Ratio ◽  
Confining Pressures ◽  
Coastal Sand ◽  
Number Of Cycles

AbstractStress controlled cyclic triaxial tests have been carried out on coastal sand of Digha, West Bengal, India at different frequencies, confining pressures, relative densities and number of loading cycles for determination of influence of these parameters on cyclic strength (expressed in terms of cyclic stress ratio) and initial liquefaction of Digha sand. The test results provide evidence that increasing density of sand increases liquefaction potential, though it has been found that increase in effective confining pressure reduces cyclic strength of sand. Cyclic strength of sand decreases with increase of number of loading cycles at a specific density and a particular confining pressure. It has been observed that frequency of loading cycles does have any significant influence on the number of cycles for initial liquefaction of Digha sand. An empirical correlation has been developed on cyclic strength of sand based on these parameters and it has been found that this correlation fits quite well with the observed experimental results.

scholarly journals Impacto, em curto prazo, dos antibióticos amoxicilina e doxiciclina na qualidade microbiana de um Latossolo Vermelho-amarelo (Short-term impact of the antibiotics amoxicillin and doxycycline on the microbial quality of a Red-yellow Latosol)

2019 ◽  
Vol 12 (4) ◽  
pp. 1340
Author(s):  
Luiz Gustavo Paulon Rezende ◽  
Márcia Matiko Kondo ◽  
Rogério Melloni
Keyword(s):  
Microbial Activity ◽  
Soil Microorganisms ◽  
Microbial Quality ◽  
Environmental Matrices ◽  
Short Term ◽  
Wide Range ◽  
Keywords Antibiotics ◽  
The Impact

Concentrações residuais de antibióticos de uso compartilhado pela terapia médica humana e veterinária são cada vez mais frequentes nos mais variados tipos de matrizes ambientais; no entanto, pouco se sabe sobre o impacto que esses fármacos podem acarretar aos microrganismos do solo. Sendo assim, perturbações relacionadas à exposição da microbiota de um latossolo vermelho-amarelo brasileiro a dois antibacterianos, a amoxicilina (AMOX) e a doxiciclina (DOX), foram investigadas por meio da determinação de atividade (mg CO2) e biomassa (Cmic) microbianas, juntamente com o quociente metabólico (qCO2), em amostras de solo que receberam as seguintes concentrações desses compostos: 0,03, 0,3, 3,0, 30 e 300 mg L-1. Os resultados mostraram diferentes efeitos sobre a microbiota e de forma específica para cada antibiótico. A AMOX mostrou-se mais impactante para os microrganismos do solo, com redução da biomassa e aumento do qCO2, enquanto que a DOX reduziu a atividade microbiana, mas sem efeito na biomassa e qCO2.A B S T R A C TThe residual concentrations of antibiotics used by human and veterinary medical therapy are increasingly common in a wide range of environmental matrices, nevertheless little is known about the impact of these drugs on to the soil microorganisms. Therefore, disturbances related to the exposure of the microbiota of a Brazilian Red-yellow Latosol to two antibacterials, amoxicillin (AMOX) and doxycycline (DOX), were investigated through the determination of the microbial activity (mg CO2) and biomass (Cmic), among with the metabolic quotient (qCO2), using soil samples spiked with: 0,03, 0,3, 3,0, 30 and 300 mg L-1 of each drug. The results showed different effects on the microbiota and in a specific way for each antibiotic. The AMOX showed higher impact impacting for the soil microorganisms, with reduction of the biomass and increase of the qCO2, whereas the DOX reduced the microbial activity, but showed no effect in the biomass and qCO2.Keywords: Antibiotics. Amoxicillin. Doxycycline. Bioindicators. Latosols.

scholarly journals Appraising and developing ST-X field determination of uncertainties by DST analysis

2016 ◽  
Vol 19 (1) ◽  
pp. 27-34
Author(s):  
Hung Viet Vu ◽  
Lan Cao Mai
Keyword(s):  
Numerical Approach ◽  
Low Permeability ◽  
Full Field ◽  
Field Development ◽  
Wide Range ◽  
Drilling Cost ◽  
Project Objectives ◽  
Flow Boundaries ◽  
The Impact

A subsurface uncertainties is a possible future event, which, if occurs, would affect project objectives either negatively or positively. For any given model or event, the uncertainty is the range of variation of the component parts and possible outcomes. It could be quantified approximately by either analytical model or in a more cumbersome one such as numerical approach. This paper summarizes thedetermination ofuncertainties by DST analysis in appraising and developing the ST-X gas condensate field, which is offshore Vietnam in Block 15-1O. Drill Stem Test (DST) results show that the S field has moderate to low permeability, multiple flow boundaries/barriers, and at least 2 PVT regions. To understand the impact of these and other important reservoir parameters on ultimate gas and condensate recovery and well count, the uncertainties has to be well evaluated and understood. The study demonstrates that there is a wide range of possible ultimate gas and condensate recoveries and well counts. The top causes for this wide range are permeability and flow boundaries/barriers. In addition to the subsurface risks, drilling cost of a ST-X well is very high. The high well cost in combination with the field being offshore, having low permeability and possibly numerous reservoir compartments dramatically increase the risk of a full field development.

Dynamic elastic properties of coal

Geophysics ◽  
2010 ◽  
Vol 75 (6) ◽  
pp. E227-E234 ◽  
Author(s):  
Anyela Morcote ◽  
Gary Mavko ◽  
Manika Prasad
Keyword(s):  
Elastic Properties ◽  
High Pressures ◽  
Confining Pressure ◽  
Acoustic Properties ◽  
Coal Rank ◽  
S Wave ◽  
Wide Range ◽  
Confining Pressures ◽  
Intrinsic Anisotropy ◽  
Dynamic Elastic Properties

Laboratory ultrasonic velocity measurements of different types of coal demonstrate that their dynamic elastic properties depend on coal rank and applied effective pressure. In spite of the growing interest in coal beds as targets for methane production, the high abundance in sedimentary sequences and the strong influence that they have on seismic response, little data are available on the acoustic properties of coal. Velocities were measured in core plugs parallel and perpendicular to lamination surfaces as a function of confining pressure up to [Formula: see text] in loading and unloading cycles. P- and S-wave velocities and dry bulk and dry shear moduli increase as coal rank increases. Thus, bituminous coal and cannel show lower velocities and moduli than higher ranked coals such as semianthracite and anthracite. The [Formula: see text] relationship for dry samples is linear and covers a relatively wide range of effective pressures and coal ranks. However, there is a pressure dependence on the elastic properties of coal for confining pressures below [Formula: see text]. This pressure sensitivity is related to the presence of microcracks. Finally, the data show that coal has an intrinsic anisotropy at confining pressures above [Formula: see text], the closing pressure for most of the microcracks. This intrinsic anisotropy at high pressures might be due to fine lamination and preferred orientation of the macerals.

scholarly journals Studies on the Efficiency of the Impact of Paraffin Inhibitors on Lowering the WAT Temperature and Reducing the Amount of Paraffin Deposit

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4653
Author(s):  
Sławomir Szuflita ◽  
Michał Pajda ◽  
Jerzy Kuśnierczyk ◽  
Mirosław Wojnicki ◽  
Marcin Warnecki
Keyword(s):  
Crude Oil ◽  
Additional Data ◽  
Solid Phase ◽  
Temperature Drop ◽  
Equilibrium Conditions ◽  
Wax Precipitation ◽  
Solid Paraffin ◽  
Wide Range ◽  
The Impact

This paper discusses the issues of the impact of pressure and temperature on the precipitation of paraffin deposits from reservoir fluids in the presence of previously prepared paraffin inhibitors. Using a properly modified PVT apparatus, the temperature of the beginning of paraffin precipitation (wax appearance temperature—WAT) has been determined, below which the solid paraffin phase was captured on a specialized filter in various temperatures. Based on the conducted experiments, a boundary has been established separating the paraffin area (the presence of paraffins as their solid phase) from an area without paraffin. Measurements of the amount of paraffin using the filter allowed the determination of the WPC (wax precipitation curve), due to which additional data is provided regarding the amount of precipitated paraffin deposit below the WAT. The developed methodology enables to conduct the measurements within a wide range of pressures using the sample saturated with reservoir gas, which can test the crude oil sample that corresponds to the actual production conditions. Most known research methods do not allow such preparation of a sample and conducting the measurements under pressurized conditions; therefore, the produced results are subject to errors. The paper describes also the studies of efficiency and differences in the action of various paraffin inhibitors. Based on the performed research, a comparison was made involving the action of agents under the pressureless conditions of dead oil and pressurized crude oil samples saturated with gas. The performed studies allowed the determination of equilibrium conditions (in a pressure–temperature system), under which deposition of the solid paraffin phase occurs during the use of three various inhibitors. Based on the performed experiments, an area with a paraffin hazard was determined, along with an area without paraffins. Due to the separation of the precipitated solid paraffin phase, an increase in the mass of the paraffin deposit associated with a temperature drop was determined (wax precipitation curve), as well as the impact of the applied inhibitors on its course.

Numerical Simulation of SHPB Test for Concrete under Confining Pressure

2014 ◽  
Vol 580-583 ◽  
pp. 3144-3148 ◽  
Author(s):  
Hua Zhang ◽  
Ao Yu Xie ◽  
Yu Wei Gao
Keyword(s):  
Strain Rate ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Properties ◽  
Confining Pressure ◽  
Hopkinson Pressure Bar ◽  
Stress Strain ◽  
Confining Pressures ◽  
Stress States ◽  
Pressure Bar ◽  
The Impact

Using the HJC dynamic constitutive model, the Split Hopkinson Pressure Bar (SHPB) impact test with confining pressure for concrete was simulated in the software ANSYS/LS-DYNA. The confining pressure was simulated by applying constant pressure around the specimen. The triangle velocity wave, which has less diffusion, is used as loader in the simulation. The confining pressures used were 0MPa, 2MPa, 4MPa, 8MPa and 16MPa and the stress-strain curves were presented. The influence of confining pressure on the dynamic properties was analyzed by comparing the stress-strain curves of concrete under different stress states. The strain rate decreases sensitively as long as the confining pressure increases. By debugging the impact velocity, the stress-strain curves under the similar strain rate were obtained, which indicate the toughening and reinforcing effect with the increase of confining pressure.

EXTRACTION OF CO-BEHAVING GENES BY SIMILARITY ENSEMBLES

2017 ◽  
Vol 25 (03) ◽  
pp. 479-494
Author(s):  
MOSLEM MOHAMMADI-JENGHARA ◽  
HOSSEIN EBRAHIMPOUR-KOMLEH
Keyword(s):  
Gene Expression ◽  
Candidate Genes ◽  
Biological Information ◽  
Data Sets ◽  
Expression Data ◽  
Yeast Gene ◽  
Ensemble Technique ◽  
Wide Range ◽  
The Impact

Microarray technology is used as a source of data for a wide range of biology studies. Useful biological information can be extracted from the analysis of microarray data, namely, the impact of a particular gene expression on the expression of other genes or the determination of expressed genes under different conditions. The purpose of this paper is to find co-behavioral genes in different data sets for different times and conditions. In other words, genes with similar behavior, same increase or decrease, under different medical, stress, and time conditions in terms of expression are determined. Multi-valued discretization of expression data was used for extracting genes with identical behavior. The algorithm proposed in this study is based on data and methods ensemble. The data ensemble technique was used to extract candidate genes with identical behavior. Other methods were also applied on all the data sets; as a result, many co-behavioral candidate genes with different similarity and correlation values were identified. Finally, the ultimate output was created from the ensemble of different methods. By applying the algorithm on yeast gene expression data, meaningful relations among genes were extracted.

Sign in / Sign up

Export Citation Format

Share Document