Penetrability of microfine cement grouts: experimental investigation and fuzzy regression modeling

2015 ◽  
Vol 52 (7) ◽  
pp. 868-882 ◽  
Author(s):  
Ioannis N. Markou ◽  
Dimitrios N. Christodoulou ◽  
Basil K. Papadopoulos
Keyword(s):  
Injection Pressure ◽  
Fuzzy Regression ◽  
Test Results ◽  
Penetration Length ◽  
Injection Process ◽  
Ordinary Regression ◽  
Microfine Cement ◽  
Cement Grouts ◽  
Microfine Cements ◽  
Sand Grain Size

One-dimensional injection tests were conducted on sand columns with a height of 134 cm for the penetrability evaluation of microfine cement grouts. Three ordinary cement types were pulverized to obtain microfine cements having nominal maximum grain sizes of 20 and 10 μm, and these cements were used in the present investigation. Suspensions with water to cement (W/C) ratios of 1, 2, and 3, by weight, were injected into 13 clean sands with d15 ranging from 0.17 to 2.25 mm and Cu ranging from 1.19 to 6.67. Pulverization of the ordinary cements to produce microfine cements extends the range of groutable sands to “medium-to-fine”. Cement fineness; suspension W/C ratio and apparent viscosity; and sand grain size, gradation, and relative density are very important parameters, as they substantially affect both grout penetration and maximum injection pressure. The penetration length of cement grouts was correlated to parameters pertinent to the suspension, sand, and injection process by performing fuzzy and ordinary linear regression analyses of the injection test results. The resultant fuzzy regression models provided successful penetration length predictions for the majority of the cases analyzed, while the best ordinary regression model exhibited a correlation coefficient not higher than 0.363.

scholarly journals Numerical Approach for the Assessment of Micro-Textured Walls Effects on Rubber Injection Moulding

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1739
Author(s):  
María García-Camprubí ◽  
Carmen Alfaro-Isac ◽  
Belén Hernández-Gascón ◽  
José Ramón Valdés ◽  
Salvador Izquierdo
Keyword(s):  
Surface Texturing ◽  
Injection Pressure ◽  
Numerical Approach ◽  
High Viscosity ◽  
Reduced Order ◽  
Flow Perturbation ◽  
Injection Process ◽  
Elastomeric Materials ◽  
Ring Seal ◽  
Elastomeric Seals

Micro-surface texturing of elastomeric seals is a validated method to improve the friction and wear characteristics of the seals. In this study, the injection process of high-viscosity elastomeric materials in moulds with wall microprotusions is evaluated. To this end, a novel CFD methodology is developed and implemented in OpenFOAM to address rubber flow behaviour at both microscale and macroscale. The first approach allows analyzing the flow perturbation induced by a particular surface texture and generate results to calculate an equivalent wall shear stress that is introduced into the macroscale case through reduced order modelling. The methodology is applied to simulate rubber injection in textured moulds in an academic case (straight pipe) and a real case (D-ring seal mould). In both cases, it is shown that textured walls do not increase the injection pressure and therefore the manufacturing process is not adversely affected.

scholarly journals Experimental Study on the Effects of Stress Variations on the Permeability of Feldspar-Quartz Sandstone

Geofluids ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
Fugang Wang ◽  
Zhaoxu Mi ◽  
Zhaojun Sun ◽  
Xufeng Li ◽  
Tianshan Lan ◽  
...  
Keyword(s):  
Injection Pressure ◽  
Confining Pressure ◽  
Repeated Loading ◽  
Micropore Structure ◽  
Injection Process ◽  
Reservoir Permeability ◽  
Stress Changes ◽  
Cyclic Variations ◽  
Loading And Unloading ◽  
Stress Variations

The multistage and discontinuous nature of the injection process used in the geological storage of CO2 causes reservoirs to experience repeated loading and unloading. The reservoir permeability changes caused by this phenomenon directly impact the CO2 injection process and the process of CO2 migration in the reservoirs. Through laboratory experiments, variations in the permeability of sandstone in the Liujiagou formation of the Ordos CO2 capture and storage (CCS) demonstration project were analyzed using cyclic variations in injection pressure and confining pressure and multistage loading and unloading. The variation in the micropore structure and its influence on the permeability were analyzed based on micropore structure tests. In addition, the effects of multiple stress changes on the permeability of the same type of rock with different clay minerals content were also analyzed. More attention should be devoted to the influence of pressure variations on permeability in evaluations of storage potential and studies of CO2 migration in reservoirs in CCS engineering.

scholarly journals Formulating Intuitionistic Fuzzy Regression Models: A Mathematical Programming Approach

2021 ◽  
Author(s):  
Sheng-Hsing Nien ◽  
Liang-Hsuan Chen
Keyword(s):  
Mathematical Programming ◽  
Regression Models ◽  
Fuzzy Regression ◽  
Distance Measures ◽  
Programming Approach ◽  
Mathematical Programming Problem ◽  
Explanatory Variables ◽  
Intuitionistic Fuzzy ◽  
Mathematical Programming Approach ◽  
Ordinary Regression

Abstract This study develops a mathematical programming approach to establish intuitionistic fuzzy regression models (IFRMs) by considering the randomness and fuzziness of intuitionistic fuzzy observations. In contrast to existing approaches, the IFRMs are established in terms of five ordinary regression models representing the components of the estimated triangular intuitionistic fuzzy response variable. The optimal parameters of the five ordinary regression models are determined by solving the proposed mathematical programming problem, which is linearized to make the resolution process efficient. Based on the concepts of randomness and fuzziness in the formulation processes, the proposed approach can improve on existing approaches’ weaknesses with establishing IFRMs, such as the limitation of symmetrical triangular membership (or non-membership) functions, the determination of parameter signs in the model, and the wide spread of the estimated responses. In addition, some numerical explanatory variables included in the intuitionistic fuzzy observations are also allowed in the proposed approach, even though it was developed for intuitionistic fuzzy observations. In contrast to existing approaches, the proposed approach is general and flexible in applications. Comparisons show that the proposed approach outperforms existing approaches in terms of similarity and distance measures.

Fabrication of Ultra Low-Density Binderless Sandwiching Materials by Rapid Steam Injection

2016 ◽  
Vol 852 ◽  
pp. 1482-1487
Author(s):  
Fan Cheng ◽  
Yu Hao Jiang ◽  
Jin Bo Chen ◽  
Peng Bo Lu ◽  
Ling Feng Su ◽  
...  
Keyword(s):  
Thermal Insulation ◽  
Sound Absorption ◽  
Building Materials ◽  
Bending Strength ◽  
Injection Pressure ◽  
Steam Injection ◽  
Low Density ◽  
Absorption Property ◽  
Injection Process ◽  
Injection Technology

Eco-friendly building materials with perfect thermal insulation & sound absorption property have become intriguing and eye-catching in recent years. In this work, the ultra low-density binderless sandwiching materials were firstly fabricated with ultra low-density of 60-80 kg/m3 by self-designed rapid steam injection technology. The main experimental factor of density, holding time, transmission time, steam injection pressure and fiber’s dimension was respectively investigated to their effects on formation of the new building materials. IR, Py GC-MS and AFM analysis were performed to study the mechanism of binderless sandwiching materials under steam injection process. The bending strength, thermal insulation & sound absorption property of the new materials were also studied. This new building material with no resin use and no formaldehyde release is expected to be reserved as the sandwich for designing thermal insulation & noise reduction building materials.

Parametric Study of Channeling Flow in Low Permeability Reservoir with Mudstone Interlayer

2012 ◽  
Vol 524-527 ◽  
pp. 1190-1195
Author(s):  
Jian Jun Liu ◽  
Quan Shu Li ◽  
Gui Hong Pei
Keyword(s):  
High Pressure ◽  
Water Injection ◽  
Injection Pressure ◽  
Element Model ◽  
Low Permeability ◽  
Low Permeability Reservoir ◽  
Injection Process ◽  
Well Spacing ◽  
Pressure Water ◽  
Channeling Flow

Channeling flow frequently occurs during the high pressure water injection of low permeability reservoir. The injection process is complex and covers so many parameters of which the contribution to channeling flow is necessarily to be studied. In this paper, numerical simulation is combined with sensitivity analysis method to calculate the significance of the weight of parameters to the channeling flow. First the values of different parameters are produced by using Latin hypercube method; second, by using these parameters, finite element model have been established and simulated, and the quantity of channeling flow has been calculated; then Spearman rank relation is applied to measure the relation of parameters and channeling flow. The results states that, in 10 years continuous injection, the well spacing and injection pressure have significant impact on the channeling flow. This states that during the application of high pressure water injection, the pressure and well spacing should be controlled especially.

The Research of Variation Regularity of Coal Bed Methane Production in CO2 Flooding

2013 ◽  
Vol 868 ◽  
pp. 677-681
Author(s):  
Yang Liu ◽  
Di Wu
Keyword(s):  
Methane Production ◽  
Injection Pressure ◽  
Initial Pressure ◽  
Coal Bed ◽  
Coal Bed Methane ◽  
Mixed Gas ◽  
Methane Recovery ◽  
Factors Affecting ◽  
Gas Concentration ◽  
Injection Process

CO2flooding can increase coal bed methane production rate, enhance coal bed methane recovery and store CO2into underground. It has good application prospect for CBM development. This paper analyzes the adsorption-desorption law of mixed gas in the coal during the CO2injection process, as well as the diffusion and seepage law of gas in the coal seam. The sensitivity of factors affecting coal bed methane production is studied and then the coal bed methane production under different conditions is simulated numerically. The results show that methane concentration and coals permeability are the two key factors affecting the output of coal bed gas and their influence on productivity are even more significant than injection pressure and initial pressure. The higher injection pressure, coals permeability and gas concentration, the greater amount of methane the coal reservoirs will yield. When the coals permeability and the gas concentration in coal reservoirs increase, the growth rate of methane production accelerates accordingly.

Technology and Mechanical Properties of Samples Obtained by Injection From Arboform L, V3 Nature Reinforced With Aramid Fibers

2014 ◽  
Author(s):  
Dumitru Nedelcu ◽  
Constantin Carausu ◽  
Ciprian Ciofu
Keyword(s):  
Mechanical Properties ◽  
Injection Pressure ◽  
Mold Temperature ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
Aramid Fibers ◽  
Injection Process ◽  
Plastic Materials ◽  
Important Trend ◽  
Manufacturing Technologies

The use of recyclable materials has become an important trend in all activity areas, reason why material based on liquid wood called Arbofill, Arboblend and Arboform will replace plastic in different applications in the near future. The new materials are the main substances that have an important effect on company development and require some simple or complex manufacturing technologies. In case of Arboform L, V3 Nature the injected parts can be obtained using the same injection machines used for the injection of plastic materials. The technological injection parameters, such as: injection pressure, injection time, cooling time, mold temperature, etc., are different. The experimental research focused on tensile strength, friction coefficients, SEM analysis, XRD analysis and EDAX analysis. Considering all of these experimental results the Arboform L, V3 Nature reinforced with aramid fibers could replace the following plastic materials PA12, PVDF, ECTFE, PA66, PA12, PC, PP, PP GF 30, etc. Also taking into account all the results obtained, this material can replace plastic materials in many applications, such as: ornaments, including for cars, connectors, switches etc., electrical industry, different mobile accessories, computers, televisions, mobile phone cases, etc. The material obtained from Arboform reinforced with aramid fibers (5% percent) improved the injection process despite of easy decreasing of mechanical properties.

Sign in / Sign up

Export Citation Format

Share Document