scholarly journals Improved Method for Measuring the Permeability of Nanoporous Material and Its Application to Shale Matrix with Ultra-Low Permeability

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1567 ◽  
Author(s):  
Taojie Lu ◽  
Ruina Xu ◽  
Bo Zhou ◽  
Yichuan Wang ◽  
Fuzhen Zhang ◽  
...  
Keyword(s):  
High Pressure ◽  
Fluid Transport ◽  
Effective Means ◽  
Clean Energy ◽  
Nanoporous Materials ◽  
Environmental Research ◽  
Low Permeability ◽  
Matrix Permeability ◽  
Wide Range ◽  
The Matrix

Nanoporous materials have a wide range of applications in clean energy and environmental research. The permeability of nanoporous materials is low, which affects the fluid transport behavior inside the nanopores and thus also affects the performance of technologies based on such materials. For example, during the development of shale gas resources, the permeability of the shale matrix is normally lower than 10−3 mD and has an important influence on rock parameters. It is challenging to measure small pressure changes accurately under high pressure. Although the pressure decay method provides an effective means for the measurement of low permeability, most apparatuses and experiments have difficulty measuring permeability in high pressure conditions over 1.38 MPa. Here, we propose an improved experimental method for the measurement of low permeability. To overcome the challenge of measuring small changes in pressure at high pressure, a pressure difference sensor is used. By improving the constant temperature accuracy and reducing the helium leakage rate, we measure shale matrix permeabilities ranging from 0.05 to 2 nD at pore pressures of up to 8 MPa, with good repeatability and sample mass irrelevance. The results show that porosity, pore pressure, and moisture conditions influence the matrix permeability. The permeability of moist shale is lower than that of dry shale, since water blocks some of the nanopores.

A Novel Coreflood Test to Evaluate EOR Potential of Wettability-Altering Surfactants in Oil-Wet Heterogeneous Carbonate Reservoirs

2021 ◽  
Author(s):  
Yue Shi ◽  
Kishore Mohanty ◽  
Manmath Panda
Keyword(s):  
Oil Recovery ◽  
Carbonate Reservoirs ◽  
Wettability Alteration ◽  
Low Permeability ◽  
High Permeability ◽  
Matrix Permeability ◽  
Rock Heterogeneity ◽  
The Matrix ◽  
Flow Through ◽  
Main Factors

Abstract Oil-wetness and heterogeneity (i.e., existence of low and high permeability regions) are two main factors that result in low oil recovery by waterflood in carbonate reservoirs. The injected water is likely to flow through high permeability regions and bypass the oil in low permeability matrix. In this study, systematic coreflood tests were carried out in both "homogeneous" cores and "heterogeneous" cores. The heterogeneous coreflood test was proposed to model the heterogeneity of carbonate reservoirs, bypassing in low-permeability matrix during waterfloods, and dynamic imbibition of surfactant into the low-permeability matrix. The results of homogeneous coreflood tests showed that both secondary-waterflood and secondary-surfactant flood can achieve high oil recovery (>50%) from relatively homogenous cores. A shut-in phase after the surfactant injection resulted in an additional oil recovery, which suggests enough time should be allowed while using surfactants for wettability alteration. The core with a higher extent of heterogeneity produced lower oil recovery to waterflood in the coreflood tests. Final oil recovery from the matrix depends on matrix permeability as well as the rock heterogeneity. The results of heterogeneous coreflood tests showed that a slow surfactant injection (dynamic imbibition) can significantly improve the oil recovery if the oil-wet reservoir is not well-swept.

scholarly journals Emerging Technologies for Food Safety: High Pressure Processing (HPP) and Cold Plasma Technology (CPT) for Decontamination of Foods

2019 ◽  
Vol 36 (1) ◽  
pp. 35-43
Author(s):  
Farahnaaz Feroz ◽  
Showshan Nafisa ◽  
Rashed Noor
Keyword(s):  
High Pressure ◽  
Effective Means ◽  
High Pressure Processing ◽  
Plasma Technology ◽  
Natural Gases ◽  
Food Borne Pathogens ◽  
Food Borne ◽  
Wide Range ◽  
Reactive Gases ◽  
Thermal Food Processing

Foods may become contaminated from a variety of sources, therefore it is imperative to understand and discover easy, cheap and effective means of decontaminating foods. Heat, although effective, economical and easily available, has been reported to produce undesirable effects on food such as loss of taste and nutrition. High Pressure Processing can inactivate the cells of the food borne pathogens and organisms responsible for food spoilage regardless of the temperature without making changes to the texture, color or flavor. Equipment involved in HPP includes a pressure vessel, pumps generating high hydrostatic pressure or intensifiers. Its success depends on certain factors such as pressure of water, temperature used during the treatment, and the properties and state of the food and categories of microorganisms found in food.Cold Plasma Technology (CPT) is a novel, non-thermal food processing technology that uses energetic and reactive gases to inactivate contaminating microorganisms in food products. CPT is environmentally friendly that uses natural gases such as nitrogen, argon, air, hydrogen, and oxygen. Depending on the plasma type, it can inactivate a wide range of microorganisms including food borne pathogens and spoilage organisms. This technology hasa low running cost (Cost of natural gases and electricity).Both HPP and CPT can spread and work on the entire food sample, regardless of shape and size. These methods serve as an alternative to some methods which were previously used. Bangladesh J Microbiol, Volume 36 Number 1 June 2019, pp 35-43

The State versus the People

2020 ◽  
Author(s):  
Matthew Rendle
Keyword(s):  
French Revolution ◽  
Effective Means ◽  
State Control ◽  
Scarce Resources ◽  
Soviet State ◽  
The People ◽  
Wide Range ◽  
Complex Picture ◽  
The Military

This book provides the first detailed account of the role of revolutionary justice in the early Soviet state. Law has often been dismissed by historians as either unimportant after the October Revolution amid the violence and chaos of civil war or even, in the absence of written codes and independent judges, little more than another means of violence. This is particularly true of the most revolutionary aspect of the new justice system, revolutionary tribunals—courts inspired by the French Revolution and established to target counter-revolutionary enemies. This book paints a more complex picture. The Bolsheviks invested a great deal of effort and scarce resources into building an extensive system of tribunals that spread across the country, including into the military and the transport network. At their peak, hundreds of tribunals heard hundreds of thousands of cases every year. Not all ended in harsh sentences: some were dismissed through lack of evidence; others given a wide range of sentences; others still suspended sentences; and instances of early release and amnesty were common. This book, therefore, argues that law played a distinct and multifaceted role for the Bolsheviks. Tribunals stood at the intersection between law and violence, offering various advantages to the Bolsheviks, not least strengthening state control, providing a more effective means of educating the population on counter-revolution, and enabling a more flexible approach to the state’s enemies. All of this adds to our understanding of the early Soviet state and, ultimately, of how the Bolsheviks held on to power.

scholarly journals Influence of Alumina Nanofibers Sintered by the Spark Plasma Method on Nickel Mechanical Properties

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 548 ◽  
Author(s):  
Leonid Agureev ◽  
Valeriy Kostikov ◽  
Zhanna Eremeeva ◽  
Svetlana Savushkina ◽  
Boris Ivanov ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Elastic Modulus ◽  
Strength Properties ◽  
Alumina Nanoparticles ◽  
Metal Powders ◽  
Wide Range ◽  
The Matrix ◽  
Spark Plasma ◽  
Average Size

The article presents the study of alumina nanoparticles’ (nanofibers) concentration effect on the strength properties of pure nickel. The samples were obtained by spark plasma sintering of previously mechanically activated metal powders. The dependence of the grain size and the relative density of compacts on the number of nanofibers was investigated. It was found that with an increase in the concentration of nanofibers, the average size of the matrix particles decreased. The effects of the nanoparticle concentration (0.01–0.1 wt.%) on the elastic modulus and tensile strength were determined for materials at 25 °C, 400 °C, and 750 °C. It was shown that with an increase in the concentration of nanofibers, a 10–40% increase in the elastic modulus and ultimate tensile strength occurred. A comparison of the mechanical properties of nickel in a wide range of temperatures, obtained in this work with materials made by various technologies, is carried out. A description of nanofibers’ mechanisms of influence on the structure and mechanical properties of nickel is given. The possible impact of impurity phases on the properties of nickel is estimated. The tendency of changes in the mechanical properties of nickel, depending on the concentration of nanofibers, is shown.

scholarly journals Estimating the number of usability problems affecting medical devices: modelling the discovery matrix

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Vincent Vandewalle ◽  
Alexandre Caron ◽  
Coralie Delettrez ◽  
Renaud Périchon ◽  
Sylvia Pelayo ◽  
...  
Keyword(s):  
Medical Devices ◽  
Market Access ◽  
Real Life ◽  
Usability Testing ◽  
Probability Of Detection ◽  
Usability Problems ◽  
Usability Problem ◽  
Wide Range ◽  
The Matrix ◽  
Problem Detection

Abstract Background Usability testing of medical devices are mandatory for market access. The testings’ goal is to identify usability problems that could cause harm to the user or limit the device’s effectiveness. In practice, human factor engineers study participants under actual conditions of use and list the problems encountered. This results in a binary discovery matrix in which each row corresponds to a participant, and each column corresponds to a usability problem. One of the main challenges in usability testing is estimating the total number of problems, in order to assess the completeness of the discovery process. Today’s margin-based methods fit the column sums to a binomial model of problem detection. However, the discovery matrix actually observed is truncated because of undiscovered problems, which corresponds to fitting the marginal sums without the zeros. Margin-based methods fail to overcome the bias related to truncation of the matrix. The objective of the present study was to develop and test a matrix-based method for estimating the total number of usability problems. Methods The matrix-based model was based on the full discovery matrix (including unobserved columns) and not solely on a summary of the data (e.g. the margins). This model also circumvents a drawback of margin-based methods by simultaneously estimating the model’s parameters and the total number of problems. Furthermore, the matrix-based method takes account of a heterogeneous probability of detection, which reflects a real-life setting. As suggested in the usability literature, we assumed that the probability of detection had a logit-normal distribution. Results We assessed the matrix-based method’s performance in a range of settings reflecting real-life usability testing and with heterogeneous probabilities of problem detection. In our simulations, the matrix-based method improved the estimation of the number of problems (in terms of bias, consistency, and coverage probability) in a wide range of settings. We also applied our method to five real datasets from usability testing. Conclusions Estimation models (and particularly matrix-based models) are of value in estimating and monitoring the detection process during usability testing. Matrix-based models have a solid mathematical grounding and, with a view to facilitating the decision-making process for both regulators and device manufacturers, should be incorporated into current standards.

The Application of Fluoresced Gel for the First Alkali Silica Reaction Evidence in Thailand

2011 ◽  
Vol 368-373 ◽  
pp. 613-616 ◽  
Author(s):  
Suvimol Sujjavanich ◽  
Krit Won-In ◽  
Wacharakorn Wongkhamchan ◽  
Pisutti Dararutana
Keyword(s):  
Uv Light ◽  
Effective Means ◽  
Accelerated Expansion ◽  
Alkali Silica Reaction ◽  
Interface Zone ◽  
Expansion Test ◽  
Existing Structures ◽  
Coarse Aggregates ◽  
The Matrix ◽  
Cracked Structures

The study of the first alkali silica reaction (ASR) case in Thailand was conducted on fluoresced gel under UV light technique. It was done on ten random cored samples from different cracked structures of ten year-aged project and the other three cored samples from no-crack structure of one building and two bridges, ages older than 40 years. It was study on areas of suspected ASR gel in the interface zone (ITZ), aggregates and paste in the vicinity. The results of reflected area indicated the evidence of ASR gel at aggregate’s rim and the nearly areas as well as in some cracks in the matrix of 9 in 11 samples of the first set. The amount of reactive coarse aggregates was found in the range of 5-90% of total coarse aggregate content, which was supported by the expansion results of same cored samples from previous study. The results of this study indicated that the fluoresced gel technique provided the satisfied results which confirmed the accelerated expansion test from previous study. They can be used as an effective means for ASR screening test of existing structures both in the field and in laboratory.

Ni Content Surface Layer Produced by Laser Surface Treatment on Amorphisable Cu Base Alloy

2010 ◽  
Vol 649 ◽  
pp. 101-106
Author(s):  
Mária Svéda ◽  
Dóra Janovszky ◽  
Kinga Tomolya ◽  
Jenő Sólyom ◽  
Zoltán Kálazi ◽  
...  
Keyword(s):  
Surface Layer ◽  
Surface Treatment ◽  
Laser Cladding ◽  
Base Alloy ◽  
Laser Surface ◽  
Laser Alloying ◽  
Laser Surface Treatment ◽  
Ni Content ◽  
Wide Range ◽  
The Matrix

The aim of our research was to comparatively examine Ni content surface layers on amorphisable Cu base alloy produced by different laser surface treatments. Laser surface treatment (LST) techniques, such as laser surface melting, laser alloying and laser cladding, provide a wide range of interesting solutions for the production of wear and corrosion resistant surfaces. [1,2] With LST techniques, the surface can be: i) coated with a layer of another material by laser cladding, ii) the composition of the matrix can be modified by laser alloying. [3] Two kinds of laser surface treatment technologies were used. In the case of coating-melting technology a Ni content surface layer was first developed by galvanization, and then the Ni content layer was melted together with the matrix. In the case of powder blowing technology Ni3Al powder was blown into the layer melted by laser beam and Argon gas. LST was performed using an impulse mode Nd:YAG laser. The laser power and the interaction time were 2 kW and 20÷60 ms. The characterization of the surface layer microstructure was performed by XRD, scanning electron microscopy and microhardness measurements.

scholarly journals Annealing of Al-Zn-Mg-Cu Alloy at High Pressures: Evolution of Microstructure and the Corrosion Behavior

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2076
Author(s):  
Chuanjun Suo ◽  
Pan Ma ◽  
Yandong Jia ◽  
Xiao Liu ◽  
Xuerong Shi ◽  
...  
Keyword(s):  
High Pressure ◽  
High Pressures ◽  
Electrochemical Impedance ◽  
Extrusion Direction ◽  
Corrosion Properties ◽  
Cu Alloy ◽  
The Matrix ◽  
Annealing Pressure ◽  
Corrosion Pits ◽  
Evolution Of Microstructure

Extruded Al-Zn-Mg-Cu alloy samples with grains aligned parallel to the extrusion direction were subjected to high-pressure annealing. The effects of annealing pressure on the microstructure, hardness, and corrosion properties (evaluated using potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS)) were investigated. Phase analysis showed the presence of MgZn2 and α-Al phases, the MgZn2 phase dissolved into the matrix, and its amount decreased with the increasing annealing pressure. The recrystallization was inhibited, and the grains were refined, leading to an increase in the Vickers hardness with increasing the annealing pressure. The corrosion resistance was improved after high-pressure treatment, and a stable passivation layer was observed. Meanwhile, the number of corrosion pits and the width of corrosion cracks decreased in the high-pressure annealed samples.

Using CFD to Enhance the Preliminary Design of High-Pressure Steam Turbines

2013 ◽  
Author(s):  
Juri Bellucci ◽  
Federica Sazzini ◽  
Filippo Rubechini ◽  
Andrea Arnone ◽  
Lorenzo Arcangeli ◽  
...  
Keyword(s):  
High Pressure ◽  
Steam Turbine ◽  
Design Tool ◽  
Tip Clearance ◽  
Large Set ◽  
Preliminary Design ◽  
Steam Turbines ◽  
High Pressure Steam ◽  
Wide Range ◽  
Pressure Steam

This paper focuses on the use of the CFD for improving a steam turbine preliminary design tool. Three-dimensional RANS analyses were carried out in order to independently investigate the effects of profile, secondary flow and tip clearance losses, on the efficiency of two high-pressure steam turbine stages. The parametric study included geometrical features such as stagger angle, aspect ratio and radius ratio, and was conducted for a wide range of flow coefficients to cover the whole operating envelope. The results are reported in terms of stage performance curves, enthalpy loss coefficients and span-wise distribution of the blade-to-blade exit angles. A detailed discussion of these results is provided in order to highlight the different aerodynamic behavior of the two geometries. Once the analysis was concluded, the tuning of a preliminary steam turbine design tool was carried out, based on a correlative approach. Due to the lack of a large set of experimental data, the information obtained from the post-processing of the CFD computations were applied to update the current correlations, in order to improve the accuracy of the efficiency evaluation for both stages. Finally, the predictions of the tuned preliminary design tool were compared with the results of the CFD computations, in terms of stage efficiency, in a broad range of flow coefficients and in different real machine layouts.

Synthesize Ti3SiC2 and Ti3SiC2-Diamond Composites at High Pressure and High Temperature

2012 ◽  
Vol 512-515 ◽  
pp. 671-675 ◽  
Author(s):  
Ai Guo Zhou ◽  
Liang Li ◽  
Tai Chao Su ◽  
Shang Sheng Li
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Intermediate Products ◽  
Diamond Particles ◽  
Ternary Carbide ◽  
The Matrix

Ti3SiC2, a ternary carbide, was proposed at this paper to use as the binder of polycrystalline diamonds to overcome the weaknesses of traditional metal binders and ceramic binders. Ti3SiC2was first reported to be in-situ synthesized under high pressure (4GPa) and at high temperature (1400°C) (HPHT) from the mixtures of Ti, Si and graphite powders or the mixture of Ti, SiC and graphite powders. Ti3SiC2-damond composites were also made at HPHT from the previous mixtures and diamond particles. TiCx, Ti5Si3Cxand TiSi2were main impurities and/or intermediate products of Ti3SiC2samples synthesized at HPHT. Ti3SiC2content increased as synthesized time increased from 10 min to 60 min. For as-synthesized composites, diamond particles were evenly distributed in matrix. The diamond particles are bonded well with the matrix by three types of interface.

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