Chemical reactions with accelerated ions. Chemical effects following interaction between chromium ions and solid oxyanion systems

1966 ◽  
Vol 62 (0) ◽  
pp. 3427-3439 ◽  
Author(s):  
T. Andersen ◽  
G. Sørensen
Keyword(s):  
Chemical Reactions ◽  
Chromium Ions ◽  
Chemical Effects

Impact of EGR on the surface functional groups of diesel engine particles based on NEXAFS

RSC Advances ◽  
2016 ◽  
Vol 6 (62) ◽  
pp. 57363-57370 ◽  
Author(s):  
Y. Zhao ◽  
Z. Wang ◽  
G. J. Xu ◽  
M. D. Li
Keyword(s):  
Diesel Engine ◽  
Functional Groups ◽  
Chemical Reactions ◽  
Surface Functional Groups ◽  
Chemical Effects ◽  
Physical And Chemical ◽  
Thermal Dilution

The thermal, dilution and chemical effects of EGR result in relatively significant changes in the formation environment, in the physical and chemical reactions of particles and in the functional groups of the matter that constitutes the particles.

THE PROPERTIES OF SALT-CLAY ROAD-SURFACING MIXTURES

1936 ◽  
Vol 14b (1) ◽  
pp. 41-46
Author(s):  
A. F. Gill
Keyword(s):  
Beneficial Effect ◽  
Chemical Reactions ◽  
Drying Shrinkage ◽  
Field Trials ◽  
Complete Elimination ◽  
Salt Treatment ◽  
Chemical Effects ◽  
Physical Chemical ◽  
Road Surfaces ◽  
Main Effect

This paper describes experiments designed to throw light on the mechanism underlying the beneficial effect that had been observed in field trials of salt treatment of clay road surfaces. Data are presented which show that no chemical reactions are involved, and that physical-chemical effects are of negligible importance. The results indicate that the main effect of salt additions to the clay is a greatly decreased rate of drying, together with, under ideal conditions, complete elimination of drying shrinkage.

What Is Really Happening When Parent and Child Wells Interact?

2021 ◽  
Vol 73 (11) ◽  
pp. 28-31
Author(s):  
Trent Jacobs
Keyword(s):  
Fiber Optics ◽  
Chemical Reactions ◽  
Fracture Network ◽  
Technical Conference ◽  
Data Sets ◽  
Physical Mechanisms ◽  
Chemical Effects ◽  
Parents And Children ◽  
Fracture Models ◽  
Rich Data

When trying to understand the well-to-well events known as frac hits and fracture-driven interactions (FDIs), the first idea to embrace is this: they are not all the same. “And the key physical mechanisms are not the same,” said Mark McClure, who added that, “Until you’ve really dialed in on what those are, you’re really in the dark.” McClure is the cofounder and CEO of ResFrac Corp. In March, the modeling firm began a multiclient study to diagnose the relationships between parent and child wells—or what many consider to be the ultimate subsurface challenge facing the shale sector. Participating operators are Marathon Oil, Hess Corp., Pioneer Resources, Arc Resources, Birchcliff Energy, SM Energy, and Ovintiv Inc. These independent E&Ps represent a cross section of some of the most active plays in North America: the Midland and Delaware basins and the Bakken and Montney shales. But what makes the study unique, McClure said, is that it involves 10 rich data sets from well pads that were subjected to a number of cross-validating diagnostics: tracers, pressure/interference monitoring, geochemistry, and fiber optics. ResFrac has been using that data to calibrate its coupled reservoir-fracture models to see what knobs clients might want to turn in the future to improve well economics. The study is also trying to unearth some firm answers about what is really happening during offset stimulations, why it is happening, and what can be done to mitigate negative outcomes. ResFrac and its clients expect to wrap up this part of the study by the year’s end and to submit an abstract for an SPE technical conference in 2022. As the study nears an end, McClure offered some of his key observations that he noted are supported by previous research found within industry literature. So, What’s the Worst That Can Happen? A growing chorus of subsurface experts consider unwanted chemical reactions in the fracture network as one of the major damage mechanisms resulting from FDIs. McClure is not only among them, he said chemical effects represent the “worst” that can happen when parents and children interact. “This is where you see wells get hit, they lose 80% of their production, and it doesn’t come back,” he explained. Some in the industry have taken to calling the byproduct of these chemical reactions “shmoo” or “gunk.” For answers as to why this is happening, McClure points to two technical papers in particular.

scholarly journals The Influence of Physical and Chemical Reactions on Water Leakage in a Multiarch Tunnel

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Jian-Xun Shi ◽  
Zhao-Hui Li ◽  
Yong-Qiang He ◽  
Guo-Ming Zhang ◽  
Ming-Qiang Wei
Keyword(s):  
Chemical Reactions ◽  
Concrete Lining ◽  
Chemical Components ◽  
Water Leakage ◽  
Chemical Effects ◽  
Under Construction ◽  
And Control ◽  
Physical And Chemical ◽  
The Relationship ◽  
Spontaneous Reaction

In many tunnels in China, the groundwater is acidic and carbonated, causing in challenges in the prevention and control of leakages of the existing tunnels and tunnels under construction. Research on tunnel leakage and the physical and chemical effects of water due to water-rock interactions is a trending topic. In addition, there is a big difference between the waterproof and drainage of multiarch tunnels and separate tunnels. In this study, the mechanism of the interaction between the groundwater and the surrounding rock of a multiarch tunnel were analyzed. The relationship between the leakage of a multiarch tunnel and the interaction between the surrounding rocks and groundwater was determined by analyzing the interaction between the chemical components in the groundwater, rocks, and the concrete lining. A mathematical model was established based on the physical and chemical reactions in the rock surrounding the tunnel, and the RNCDX.FOR program was compiled using the simplex Monte Carlo method. The total free energy in the entire system varied significantly, and the value of objective function (J) reflected the trend of the system's spontaneous reaction. As J decreased, the reaction power of the system increased. The more significant the erosion of the rocks was by the groundwater, the more channels were created by the groundwater in the rock, and the more likely the water leakage was.

Surface reactions observed by photoemission electron microscopy (PEEM)

1992 ◽  
Vol 50 (1) ◽  
pp. 286-287
Author(s):  
H.H. Rotermund
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Work Function ◽  
Chemical Reactions ◽  
Reaction Diffusion ◽  
Dynamic Processes ◽  
Clean Surface ◽  
Crystal Surfaces ◽  
Single Crystal Surfaces ◽  
Photoemission Electron

Chemical reactions at a surface will in most cases show a measurable influence on the work function of the clean surface. This change of the work function δφ can be used to image the local distributions of the investigated reaction,.if one of the reacting partners is adsorbed at the surface in form of islands of sufficient size (Δ>0.2μm). These can than be visualized via a photoemission electron microscope (PEEM). Changes of φ as low as 2 meV give already a change in the total intensity of a PEEM picture. To achieve reasonable contrast for an image several 10 meV of δφ are needed. Dynamic processes as surface diffusion of CO or O on single crystal surfaces as well as reaction / diffusion fronts have been observed in real time and space.

Microwaves: Application in Electron Microscopy

1990 ◽  
Vol 48 (3) ◽  
pp. 140-141
Author(s):  
Anthony S-Y Leong ◽  
David W Gove
Keyword(s):  
Electron Microscopy ◽  
Light Microscopy ◽  
Chemical Reactions ◽  
Electromagnetic Waves ◽  
Tissue Fixation ◽  
Primary Method ◽  
Dipolar Molecules ◽  
Wide Range ◽  
Time Required ◽  
Cryostat Sections

Microwaves (MW) are electromagnetic waves which are commonly generated at a frequency of 2.45 GHz. When dipolar molecules such as water, the polar side chains of proteins and other molecules with an uneven distribution of electrical charge are exposed to such non-ionizing radiation, they oscillate through 180° at a rate of 2,450 million cycles/s. This rapid kinetic movement results in accelerated chemical reactions and produces instantaneous heat. MWs have recently been applied to a wide range of procedures for light microscopy. MWs generated by domestic ovens have been used as a primary method of tissue fixation, it has been applied to the various stages of tissue processing as well as to a wide variety of staining procedures. This use of MWs has not only resulted in drastic reductions in the time required for tissue fixation, processing and staining, but have also produced better cytologic images in cryostat sections, and more importantly, have resulted in better preservation of cellular antigens.

Fine structure and properties of defects in naturally occurring silicates and oxides

1990 ◽  
Vol 48 (4) ◽  
pp. 460-461
Author(s):  
David R. Veblen
Keyword(s):  
Chemical Reactions ◽  
High Resolution Electron Microscopy ◽  
Extended Defects ◽  
Single Chain ◽  
Naturally Occurring ◽  
Resolution Electron ◽  
Fine Structures ◽  
Image Simulations ◽  
Similar Crystal Structure

Extended defects and interfaces control many processes in rock-forming minerals, from chemical reactions to rock deformation. In many cases, it is not the average structure of a defect or interface that is most important, but rather the structure of defect terminations or offsets in an interface. One of the major thrusts of high-resolution electron microscopy in the earth sciences has been to identify the role of defect fine structures in reactions and to determine the structures of such features. This paper will review studies using HREM and image simulations to determine the structures of defects in silicate and oxide minerals and present several examples of the role of defects in mineral chemical reactions. In some cases, the geological occurrence can be used to constrain the diffusional properties of defects.The simplest reactions in minerals involve exsolution (precipitation) of one mineral from another with a similar crystal structure, and pyroxenes (single-chain silicates) provide a good example. Although conventional TEM studies have led to a basic understanding of this sort of phase separation in pyroxenes via spinodal decomposition or nucleation and growth, HREM has provided a much more detailed appreciation of the processes involved.

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