Factors affecting arsenic mobility from hydrothermally altered rock in impoundment-type in situ experiments

Understanding seed germination and seedling recruitment is important for managing long-lived plant species, particularly palms that are transplanted from the wild and where regeneration is suppressed by seed predators and exotic herbivores. Seed viability, the timing of germination, and the factors influencing germination were investigated for the cabbage tree palm, Livistona australis (R.Br.) Mart. Greenhouse studies were combined with in situ experiments conducted on the Australian mainland and on a nearby mammal-free island. Under greenhouse conditions, >90% of seed germinated within 4 months. In the field, burial rather than surface sowing of seed increased germination success. Seed without mesocarp and in sunlight had increased germination when compared with fruits in shade on the island, whereas neither presence/absence of mesocarp or light levels had any effect on the mainland. Germination success was substantially lower on the mainland, primarily because of high seed predation from the native bush rat, Rattus fuscipes. When caged to exclude vertebrates, 44% of seed were damaged over time by pathogens and invertebrates, with losses greater in sunlight than in shade. Results from the present study indicate that freshly buried seed with the mesocarp removed would have the greatest potential success in promoting the restoration of L. australis at degraded sites.

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An in situ and ex situ TEM study of the formation of thin cobalt silicide films by molecular beam epitaxy on the silicon (100) surface

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010010648x ◽

1988 ◽

Vol 46 ◽

pp. 884-885

Author(s):

D. Loretto ◽

J. M. Gibson ◽

S. M. Yalisove ◽

R. T. Tung

Keyword(s):

Molecular Beam Epitaxy ◽

Molecular Beam ◽

Defect Density ◽

High Vacuum ◽

Ultra High Vacuum ◽

Ex Situ ◽

Metal Base ◽

In Situ Experiments ◽

Potential Applications

The cobalt disilicide/silicon system has potential applications as a metal-base and as a permeable-base transistor. Although thin, low defect density, films of CoSi2 on Si(111) have been successfully grown, there are reasons to believe that Si(100)/CoSi2 may be better suited to the transmission of electrons at the silicon/silicide interface than Si(111)/CoSi2. A TEM study of the formation of CoSi2 on Si(100) is therefore being conducted. We have previously reported TEM observations on Si(111)/CoSi2 grown both in situ, in an ultra high vacuum (UHV) TEM and ex situ, in a conventional Molecular Beam Epitaxy system.The procedures used for the MBE growth have been described elsewhere. In situ experiments were performed in a JEOL 200CX electron microscope, extensively modified to give a vacuum of better than 10-9 T in the specimen region and the capacity to do in situ sample heating and deposition. Cobalt was deposited onto clean Si(100) samples by thermal evaporation from cobalt-coated Ta filaments.

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Electron and ion irradiation-induced dissolution of mechanical twins in the intermetalic U3Si: An in situ HVEM study

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100155232 ◽

1989 ◽

Vol 47 ◽

pp. 652-653

Author(s):

Charles W. Allen ◽

Robert C. Birtcher

Keyword(s):

Elevated Temperatures ◽

Ion Irradiation ◽

Ion Beam ◽

National Laboratory ◽

Argonne National Laboratory ◽

Heavy Ion ◽

High Energy ◽

Mechanical Twinning ◽

In Situ Experiments

The uranium silicides, including U3Si, are under study as candidate low enrichment nuclear fuels. Ion beam simulations of the in-reactor behavior of such materials are performed because a similar damage structure can be produced in hours by energetic heavy ions which requires years in actual reactor tests. This contribution treats one aspect of the microstructural behavior of U3Si under high energy electron irradiation and low dose energetic heavy ion irradiation and is based on in situ experiments, performed at the HVEM-Tandem User Facility at Argonne National Laboratory. This Facility interfaces a 2 MV Tandem ion accelerator and a 0.6 MV ion implanter to a 1.2 MeV AEI high voltage electron microscope, which allows a wide variety of in situ ion beam experiments to be performed with simultaneous irradiation and electron microscopy or diffraction.At elevated temperatures, U3Si exhibits the ordered AuCu3 structure. On cooling below 1058 K, the intermetallic transforms, evidently martensitically, to a body-centered tetragonal structure (alternatively, the structure may be described as face-centered tetragonal, which would be fcc except for a 1 pet tetragonal distortion). Mechanical twinning accompanies the transformation; however, diferences between electron diffraction patterns from twinned and non-twinned martensite plates could not be distinguished.

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A computer-control program for TEM in situ fatigue experiments

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100155074 ◽

1989 ◽

Vol 47 ◽

pp. 620-621

Author(s):

Kenneth S. Vecchio ◽

John A. Hunt

Keyword(s):

Slow Crack Growth ◽

Computer Control ◽

Control Program ◽

Video Tape ◽

Computer Control System ◽

Transmission Electron ◽

In Situ Experiments ◽

Tremendous Amount ◽

And Control

In-situ experiments conducted within a transmission electron microscope provide the operator a unique opportunity to directly observe microstructural phenomena, such as phase transformations and dislocation-precipitate interactions, “as they happen”. However, in-situ experiments usually require a tremendous amount of experimental preparation beforehand, as well as, during the actual experiment. In most cases the researcher must operate and control several pieces of equipment simultaneously. For example, in in-situ deformation experiments, the researcher may have to not only operate the TEM, but also control the straining holder and possibly some recording system such as a video tape machine. When it comes to in-situ fatigue deformation, the experiments became even more complicated with having to control numerous loading cycles while following the slow crack growth. In this paper we will describe a new method for conducting in-situ fatigue experiments using a camputer-controlled tensile straining holder.The tensile straining holder used with computer-control system was manufactured by Philips for the Philips 300 series microscopes. It was necessary to modify the specimen stage area of this holder to work in the Philips 400 series microscopes because the distance between the optic axis and holder airlock is different than in the Philips 300 series microscopes. However, the program and interfacing can easily be modified to work with any goniometer type straining holder which uses a penrmanent magnet motor.

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Coliform transport in a pristine reservoir: modeling and field studies

Water Science & Technology ◽

10.2166/wst.1998.0124 ◽

1998 ◽

Vol 37 (2) ◽

pp. 137-144 ◽

Cited By ~ 11

Author(s):

Elisa Garvey ◽

John E. Tobiason ◽

Michael Hayes ◽

Evelyn Wolfram ◽

David A. Reckhow ◽

...

Keyword(s):

Model Development ◽

Fate And Transport ◽

Field Studies ◽

Meteorological Conditions ◽

Reservoir Modeling ◽

Vertical Circulation ◽

Quality Model ◽

Circulation Patterns ◽

In Situ Experiments

This paper reports on field studies and model development aimed at understanding coliform fate and transport in the Quabbin Reservoir, an oligotrophic drinking water supply reservoir. An investigation of reservoir currents suggested the importance of wind driven phenomena, and that both lateral and vertical circulation patterns exist. In-situ experiments of coliform decay suggested dependence on light intensity and yielded an appropriate decay coefficient to be used in CE-QUAL-W2, a two-dimensional hydrodynamic and water quality model. Modeling confirmed the sensitivity of reservoir outlet concentration to vertical variability within the reservoir, meteorological conditions, and location of coliform source.

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Upscaling THM modeling from small-scale to full-scale in-situ experiments in the Callovo-Oxfordian claystone

International Journal of Rock Mechanics and Mining Sciences ◽

10.1016/j.ijrmms.2020.104582 ◽

2021 ◽

Vol 144 ◽

pp. 104582

Author(s):

D.M. Seyedi ◽

C. Plúa ◽

M. Vitel ◽

G. Armand ◽

J. Rutqvist ◽

...

Keyword(s):

Full Scale ◽

Small Scale ◽

In Situ Experiments

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Memory Effect on a LDH/zeolite A Composite: An XRD In Situ Study

Materials ◽

10.3390/ma14092102 ◽

2021 ◽

Vol 14 (9) ◽

pp. 2102

Author(s):

Breno G. P. Bezerra ◽

Lindiane Bieseki ◽

Mariele I. S. de Mello ◽

Djalma R. da Silva ◽

Cristiane B. Rodella ◽

...

Keyword(s):

Memory Effect ◽

Inert Atmosphere ◽

Effect Study ◽

Physical Mixture ◽

Zeolite A ◽

Three Samples ◽

In Situ Experiments ◽

Double Hydroxide ◽

Rehydration Process

In this memory effect study, hydrotalcite-type compounds in the lamellar double hydroxide-like (LDH)/zeolite A composite material were analyzed using X-Ray Diffration XRD) in situ experiments. Three samples were analyzed: Al,Mg-LDH, Al,Mg-LDH/ZA composite, and a physical mixture (50/50 wt%) of zeolite A and Al,Mg-LDH. The Al,Mg-LDH sample was treated at 500 °C in an O2 atmosphere and subsequently rehydrated. The Al,Mg-LDH/ZA composites had three treatments: one was performed at 300 °C in a He atmosphere, and two treatments were performed with an O2 atmosphere at 300 and 500 °C. In the physical mixture, two treatments were carried out under O2 flow at 500 °C and under He flow at 300 °C. Both went through the rehydration process. All samples were also analyzed by energy dispersive spectroscopy (EDS) and scanning electron microscopy (SEM). The results show that the LDH phase in the Al,Mg-LDH/ZA compounds has memory effects, and thus, the compound can be calcined and rehydrated. For the LDH in the composite, the best heat treatment system is a temperature of 300 °C in an inert atmosphere.

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Fabrication of monodisperse polypyrrole/SBA-15 composite for the selective removal of Cr(Ⅵ) from aqueous solutions

New Journal of Chemistry ◽

10.1039/d1nj00717c ◽

2021 ◽

Author(s):

Liang Wang ◽

Peng Gao ◽

Mengxin Liu ◽

Ziqing Huang ◽

Shixia Lan ◽

...

Keyword(s):

Aqueous Solution ◽

Aqueous Solutions ◽

Adsorption Process ◽

In Situ Polymerization ◽

Selective Removal ◽

Factors Affecting

Monodisperse polypyrrole/SBA-15 composite (PPy/SBA-15) was fabricated by in-situ polymerization and used for Cr(Ⅵ) adsorption from aqueous solution. PPy/SBA-15 was characterized by numerous approaches. Factors affecting the Cr(Ⅵ) adsorption process included...

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Analysis of TBM Tunnel Behavior in Jointed Rock Mass

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.90-93.2033 ◽

2011 ◽

Vol 90-93 ◽

pp. 2033-2036 ◽

Cited By ~ 1

Author(s):

Jin Shan Sun ◽

Hong Jun Guo ◽

Wen Bo Lu ◽

Qing Hui Jiang

Keyword(s):

Rock Mass ◽

Numerical Models ◽

Jointed Rock ◽

In Situ Stress ◽

Jointed Rock Mass ◽

Joint Orientation ◽

Joint Spacing ◽

Factors Affecting ◽

Dip Angle

The factors affecting the TBM tunnel behavior in jointed rock mass is investigated. In the numerical models the concrete segment lining of TBM tunnel is concerned, which is simulated as a tube neglecting the segment joint. And the TBM tunnel construction process is simulate considering the excavation and installing of the segment linings. Some cases are analyzed with different joint orientation, joint spacing, joint strength and tunnel depth. The results show that the shape and areas of loosing zones of the tunnel are influenced by the parameters of joint sets and in-situ stress significantly, such as dip angle, spacing, strength, and the in-situ stress statement. And the stress and deformation of the tunnel lining are influenced by the parameters of joint sets and in-situ stress, too.

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Advanced experimental approaches to marine water-column biogeochemical processes

ICES Journal of Marine Science ◽

10.1093/icesjms/fsx146 ◽

2017 ◽

Vol 75 (1) ◽

pp. 30-42 ◽

Cited By ~ 6

Author(s):

Louis Legendre ◽

Richard B Rivkin ◽

Nianzhi Jiao

Keyword(s):

Water Column ◽

Numerical Models ◽

Free Water ◽

Sea Surface ◽

Biogeochemical Processes ◽

In Situ Experiments ◽

Technological Developments ◽

Approaches To Study ◽

Experimental Approaches

Abstract This “Food for Thought” article examines the potential uses of several novel scientific and technological developments, which are currently available or being developed, to significantly advance or supplement existing experimental approaches to study water-column biogeochemical processes (WCB-processes). After examining the complementary roles of observation, experiments and numerical models to study WCB-processes, we focus on the main experimental approaches of free-water in situ experiments, and at-sea and on-land meso- and macrocosms. We identify some of the incompletely resolved aspects of marine WCB-processes, and explore advanced experimental approaches that could be used to reduce their uncertainties. We examine three such approaches: free-water experiments of lengthened duration using bioArgo floats and gliders, at-sea mesocosms deployed several 100s m below the sea-surface using new biogeochemical sensors, and 50 m-tall on-land macrocosms. These approaches could lead to significant progress in concepts related to marine WCB-processes.

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