Multi-scale pore characterization of Barakar shale in the Mand-Raigarh Basin, India: scientific upshots from geochemical approaches and imaging techniques

Heterogeneous catalysts can be of varying complexity ranging from single or double phase systems to complicated mixtures of metals and oxides with additives to help promote chemical reactions, extend the life of the catalysts, prevent poisoning etc. Although catalysis occurs on the surface of most systems, detailed descriptions of the microstructure and chemistry of catalysts can be helpful for developing an understanding of the mechanism by which a catalyst facilitates a reaction. Recent years have seen continued development and improvement of various TEM, STEM and AEM techniques for yielding information on the structure and chemistry of catalysts on the nanometer scale. Here we review some quantitative approaches to catalyst characterization that have resulted from new developments in instrumentation.HREM has been used to examine structural features of catalysts often by employing profile imaging techniques to study atomic details on the surface. Digital recording techniques employing slow-scan CCD cameras have facilitated the use of low-dose imaging in zeolite structure analysis and electron crystallography. Fig. la shows a low-dose image from SSZ-33 zeolite revealing the presence of a stacking fault.

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Coherent electron nanodiffraction from clean silver nano particles in a UHV STEM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010015112x ◽

1993 ◽

Vol 51 ◽

pp. 1058-1059

Author(s):

J. Liu ◽

M. Pan ◽

G. E. Spinnler

Keyword(s):

Supported Catalysts ◽

Imaging Techniques ◽

Nano Particles ◽

Metal Particles ◽

Shape Structure ◽

Dynamical Simulations ◽

Small Metal Particles ◽

Extract Information

Small metal particles have peculiar chemical and physical properties as compared to bulk materials. They are especially important in catalysis since metal particles are common constituents of supported catalysts. The structural characterization of small particles is of primary importance for the understanding of structure-catalytic activity relationships. The shape and size of metal particles larger than approximately 5 nm in diameter can be determined by several imaging techniques. It is difficult, however, to deduce the shape of smaller metal particles. Coherent electron nanodiffraction (CEND) patterns from nano particles contain information about the particle size, shape, structure and defects etc. As part of an on-going program of STEM characterization of supported catalysts we report some preliminary results of CEND study of Ag nano particles, deposited in situ in a UHV STEM instrument, and compare the experimental results with full dynamical simulations in order to extract information about the shape of Ag nano particles.

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Integrated, Multi-Scale Characterization of Imbibition and Wettability Phenomena Using Magnetic Resonance and Wide-Band Dielectric Measurements

10.2172/927607 ◽

2007 ◽

Author(s):

Mukul M. Sharma ◽

Steven L. Bryant ◽

Carlos Torres-Verdin ◽

George Hirasaki

Keyword(s):

Magnetic Resonance ◽

Wide Band ◽

Dielectric Measurements ◽

Multi Scale ◽

Scale Characterization

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Characterization of Steel Slag Filler and Its Effect on Aging Resistance of Asphalt Mastic with Various Aging Methods

Materials ◽

10.3390/ma14040869 ◽

2021 ◽

Vol 14 (4) ◽

pp. 869

Author(s):

Minghua Wei ◽

Shaopeng Wu ◽

Haiqin Xu ◽

Hechuan Li ◽

Chao Yang

Keyword(s):

Particle Size ◽

Surface Characterization ◽

Steel Slag ◽

Self Healing ◽

Limestone Filler ◽

Asphalt Mastic ◽

Pore Characterization ◽

Asphalt Mastics ◽

Healing Property

Steel slag is the by-product of the steelmaking industry, the negative influences of which prompt more investigation into the recycling methods of steel slag. The purpose of this study is to characterize steel slag filler and study its feasibility of replacing limestone filler in asphalt concrete by evaluating the resistance of asphalt mastic under various aging methods. Firstly, steel slag filler, limestone filler, virgin asphalt, steel slag filler asphalt mastic and limestone filler asphalt mastic were prepared. Subsequently, particle size distribution, surface characterization and pore characterization of the fillers were evaluated. Finally, rheological property, self-healing property and chemical functional groups of the asphalt mastics with various aging methods were tested via dynamic shear rheometer and Fourier transform infrared spectrometer. The results show that there are similar particle size distributions, however, different surface characterization and pore characterization in the fillers. The analysis to asphalt mastics demonstrates how the addition of steel slag filler contributes to the resistance of asphalt mastic under the environment of acid and alkaline but is harmful under UV radiation especially. In addition, the pore structure in steel slag filler should be a potential explanation for the changing resistance of the asphalt mastics. In conclusion, steel slag filler is suggested to replace limestone filler under the environment of acid and alkaline, and environmental factor should be taken into consideration when steel slag filler is applied to replace natural fillers in asphalt mastic.

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Current Trends in Non-Invasive Imaging of Interactions in the Liver Tumor Microenvironment Mediated by Tumor Metabolism

Cancers ◽

10.3390/cancers13153645 ◽

2021 ◽

Vol 13 (15) ◽

pp. 3645

Author(s):

Isabel Theresa Schobert ◽

Lynn Jeanette Savic

Keyword(s):

Tumor Microenvironment ◽

Liver Cancer ◽

Cancer Cells ◽

Imaging Techniques ◽

Treatment Strategies ◽

Tumor Metabolism ◽

Resistance Mechanisms ◽

Metabolic Reprogramming ◽

Non Invasive

With the increasing understanding of resistance mechanisms mediated by the metabolic reprogramming in cancer cells, there is a growing clinical interest in imaging technologies that allow for the non-invasive characterization of tumor metabolism and the interactions of cancer cells with the tumor microenvironment (TME) mediated through tumor metabolism. Specifically, tumor glycolysis and subsequent tissue acidosis in the realms of the Warburg effect may promote an immunosuppressive TME, causing a substantial barrier to the clinical efficacy of numerous immuno-oncologic treatments. Thus, imaging the varying individual compositions of the TME may provide a more accurate characterization of the individual tumor. This approach can help to identify the most suitable therapy for each individual patient and design new targeted treatment strategies that disable resistance mechanisms in liver cancer. This review article focuses on non-invasive positron-emission tomography (PET)- and MR-based imaging techniques that aim to visualize the crosstalk between tumor cells and their microenvironment in liver cancer mediated by tumor metabolism.

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Magnetoencephalography in the Detection and Characterization of Brain Abnormalities Associated with Traumatic Brain Injury: A Comprehensive Review

Medical Sciences ◽

10.3390/medsci9010007 ◽

2021 ◽

Vol 9 (1) ◽

pp. 7

Author(s):

Geoffrey W. Peitz ◽

Elisabeth A. Wilde ◽

Ramesh Grandhi

Keyword(s):

Traumatic Brain Injury ◽

Brain Injury ◽

Imaging Techniques ◽

Brain Connectivity ◽

Functional Brain Imaging ◽

Original Research ◽

High Temporal Resolution ◽

Post Traumatic Stress ◽

Clinical Role

Magnetoencephalography (MEG) is a functional brain imaging technique with high temporal resolution compared with techniques that rely on metabolic coupling. MEG has an important role in traumatic brain injury (TBI) research, especially in mild TBI, which may not have detectable features in conventional, anatomical imaging techniques. This review addresses the original research articles to date that have reported on the use of MEG in TBI. Specifically, the included studies have demonstrated the utility of MEG in the detection of TBI, characterization of brain connectivity abnormalities associated with TBI, correlation of brain signals with post-concussive symptoms, differentiation of TBI from post-traumatic stress disorder, and monitoring the response to TBI treatments. Although presently the utility of MEG is mostly limited to research in TBI, a clinical role for MEG in TBI may become evident with further investigation.

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The Use of Imaging Techniques in Chronic Kidney Disease-Mineral and Bone Disorders (CKD-MBD)—A Systematic Review

Diagnostics ◽

10.3390/diagnostics11050772 ◽

2021 ◽

Vol 11 (5) ◽

pp. 772

Author(s):

Ana Pimentel ◽

Jordi Bover ◽

Grahame Elder ◽

Martine Cohen-Solal ◽

Pablo Antonio Ureña-Torres

Keyword(s):

Computed Tomography ◽

Chronic Kidney Disease ◽

Magnetic Resonance ◽

Kidney Disease ◽

Imaging Techniques ◽

Quantitative Computed Tomography ◽

Vertebral Fracture Assessment ◽

Vascular Calcifications ◽

Ckd Stage

Although frequently silent, mineral and bone disease (MBD) is one of the most precocious complication of chronic kidney disease (CKD) and is omnipresent in patients with CKD stage 5. Its pathophysiology is complex, but basically, disturbances in vitamin D, phosphate, and calcium metabolism lead to a diverse range of clinical manifestations with secondary hyperparathyroidism usually being the most frequent. With the decline in renal function, CKD-MBD may induce microstructural changes in bone, vascular system and soft tissues, which results in macrostructural lesions, such as low bone mineral density (BMD) resulting in skeletal fractures, vascular and soft tissue calcifications. Moreover, low BMD, fractures, and vascular calcifications are linked with increased risk of cardiovascular mortality and all-cause mortality. Therefore, a better characterization of CKD-MBD patterns, beyond biochemical markers, is helpful to adapt therapies and monitor strategies as used in the general population. An in-depth characterization of bone health is required, which includes an evaluation of cortical and trabecular bone structure and density and the degree of bone remodeling through bone biomarkers. Standard radiological imaging is generally used for the diagnosis of fracture or pseudo-fractures, vascular calcifications and other features of CKD-MBD. However, bone fractures can also be diagnosed using computed tomography (CT) scan, magnetic resonance (MR) imaging and vertebral fracture assessment (VFA). Fracture risk can be predicted by bone densitometry using dual-energy X-ray absorptiometry (DXA), quantitative computed tomography (QTC) and peripheral quantitative computed tomography (pQTC), quantitative ultrasound (QUS) and most recently magnetic resonance micro-imaging. Quantitative methods to assess bone consistency and strength complete the study and adjust the clinical management when integrated with clinical factors. The aim of this review is to provide a brief and comprehensive update of imaging techniques available for the diagnosis, prevention, treatment and monitoring of CKD-MBD.

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