Scanning electron microscopy and molecular dynamics of surfaces of growing and ablating hexagonal ice crystals

Abstract. We present the first clearly resolved observations of surfaces of growing and ablating hexagonal ice crystals using variable-pressure scanning electron microscopy. The ice surface develops trans-prismatic strands, separated from one another by distances of 5–10 μm. The strands are present at a wide range of supersaturations, but are most pronounced at temperatures near the frost point. Pyramidal facets consistent with Miller-Bravais indices of 1011, and possibly also 2021, are associated with ice growth under these conditions. A molecular-dynamics model of a free-standing ice Ih nanocolumn containing 8400 water molecules does not develop trans-prismatic strands, suggesting these features originate at larger spatial or temporal scales. The possible relevance of these surface features to cirrus ice is discussed.

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Scanning electron microscopy and molecular dynamics of surfaces of growing and ablating hexagonal ice crystals

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-9-20739-2009 ◽

2009 ◽

Vol 9 (5) ◽

pp. 20739-20763 ◽

Cited By ~ 1

Author(s):

W. C. Pfalzgraff ◽

R. M. Hulscher ◽

S. P. Neshyba

Keyword(s):

Electron Microscopy ◽

Molecular Dynamics ◽

Scanning Electron Microscopy ◽

Climate Models ◽

Growth Conditions ◽

Ice Crystals ◽

Variable Pressure ◽

Radiative Balance ◽

Hexagonal Ice ◽

Scanning Electron

Abstract. Optical properties of cirrus ice clouds play an important role in regulating Earth's radiative balance. It has been hypothesized that the surfaces of cirrus ice crystals may be characterized by mesoscopic (micrometer-scale) texturing, or roughness, in order to explain discrepancies between theoretical and observed light-scattering properties. Here, we present the first clearly resolved observations of surfaces of hexagonal ice crystals, using variable-pressure scanning electron microscopy. During growth conditions, the ice surface develops trans-prismatic strands, separated from one another by distances of 5–10 μm. These strands become more pronounced during ablation, and exhibit a wider range of separations. Under re-growth conditions, faceting is re-established initially at prismatic edges. Molecular dynamics studies of a free-standing ice Ih nanocolumn showed no trans-prismatic strands at the atomistic level, suggesting that these strands originate at a spatial scale greater than 10 nm. The observed surface roughness could be used to construct more realistic representations of cirrus clouds in climate models, and constrain theories of ice crystal growth and ablation.

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Studying Ice with Environmental Scanning Electron Microscopy

Molecules ◽

10.3390/molecules27010258 ◽

2021 ◽

Vol 27 (1) ◽

pp. 258

Author(s):

Elzbieta Pach ◽

Albert Verdaguer

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Imaging Technique ◽

Environmental Scanning Electron Microscopy ◽

Ice Nucleation ◽

Ice Crystals ◽

Environmental Scanning ◽

Ice Dynamics ◽

Hexagonal Ice ◽

Scanning Electron

Scanning electron microscopy (SEM) is a powerful imaging technique able to obtain astonishing images of the micro- and the nano-world. Unfortunately, the technique has been limited to vacuum conditions for many years. In the last decades, the ability to introduce water vapor into the SEM chamber and still collect the electrons by the detector, combined with the temperature control of the sample, has enabled the study of ice at nanoscale. Astounding images of hexagonal ice crystals suddenly became real. Since these first images were produced, several studies have been focusing their interest on using SEM to study ice nucleation, morphology, thaw, etc. In this paper, we want to review the different investigations devoted to this goal that have been conducted in recent years in the literature and the kind of information, beyond images, that was obtained. We focus our attention on studies trying to clarify the mechanisms of ice nucleation and those devoted to the study of ice dynamics. We also discuss these findings to elucidate the present and future of SEM applied to this field.

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Scanning electron microscopy of plant cells using a variable-pressure SEM and cryogenic techniques

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100147144 ◽

1993 ◽

Vol 51 ◽

pp. 260-261

Author(s):

M. Yamada ◽

K. Ueda ◽

K. Kuboki ◽

H. Matsushima ◽

S. Joens

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Saturated Vapor ◽

Plant Cells ◽

Variable Pressure ◽

Specimen Preparation ◽

Operating Pressure ◽

Vapor Pressures ◽

Low Temperature Microscopy ◽

Scanning Electron

Use of variable Pressure SEMs is spreading among electron microscopists The variable Pressure SEM does not necessarily require specimen Preparation such as fixation, dehydration, coating, etc which have been required for conventional scanning electron microscopy. The variable Pressure SEM allows operating Pressure of 1˜270 Pa in specimen chamber It does not allow microscopy of water-containing specimens under a saturated vapor Pressure of water. Therefore, it may cause shrink or deformation of water-containing soft specimens such as plant cells due to evaporation of water. A solution to this Problem is to lower the specimen temperature and maintain saturated vapor Pressures of water at low as shown in Fig. 1 On this technique, there is a Published report of experiment to have sufficient signal to noise ratio for scondary electron imaging at a relatively long working distance using an environmental SEM. We report here a new low temperature microscopy of soft Plant cells using a variable Pressure SEM (Hitachi S-225ON).

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Microscopy Methods for Biofilm Imaging: Focus on SEM and VP-SEM Pros and Cons

Biology ◽

10.3390/biology10010051 ◽

2021 ◽

Vol 10 (1) ◽

pp. 51

Author(s):

Michela Relucenti ◽

Giuseppe Familiari ◽

Orlando Donfrancesco ◽

Maurizio Taurino ◽

Xiaobo Li ◽

...

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Ion Beam ◽

Ruthenium Red ◽

Variable Pressure ◽

Sem Images ◽

Advantages And Disadvantages ◽

Pros And Cons ◽

Microscopy Techniques ◽

Scanning Electron

Several imaging methodologies have been used in biofilm studies, contributing to deepening the knowledge on their structure. This review illustrates the most widely used microscopy techniques in biofilm investigations, focusing on traditional and innovative scanning electron microscopy techniques such as scanning electron microscopy (SEM), variable pressure SEM (VP-SEM), environmental SEM (ESEM), and the more recent ambiental SEM (ASEM), ending with the cutting edge Cryo-SEM and focused ion beam SEM (FIB SEM), highlighting the pros and cons of several methods with particular emphasis on conventional SEM and VP-SEM. As each technique has its own advantages and disadvantages, the choice of the most appropriate method must be done carefully, based on the specific aim of the study. The evaluation of the drug effects on biofilm requires imaging methods that show the most detailed ultrastructural features of the biofilm. In this kind of research, the use of scanning electron microscopy with customized protocols such as osmium tetroxide (OsO4), ruthenium red (RR), tannic acid (TA) staining, and ionic liquid (IL) treatment is unrivalled for its image quality, magnification, resolution, minimal sample loss, and actual sample structure preservation. The combined use of innovative SEM protocols and 3-D image analysis software will allow for quantitative data from SEM images to be extracted; in this way, data from images of samples that have undergone different antibiofilm treatments can be compared.

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Investigation of metal exudates from tobacco glandular trichomes under heavy metal stresses using a variable pressure scanning electron microscopy system

Plant Biotechnology ◽

10.5511/plantbiotechnology.25.407 ◽

2008 ◽

Vol 25 (4) ◽

pp. 407-411 ◽

Cited By ~ 16

Author(s):

Emiko Harada ◽

Yong-Eui Choi

Keyword(s):

Electron Microscopy ◽

Heavy Metal ◽

Scanning Electron Microscopy ◽

Glandular Trichomes ◽

Variable Pressure ◽

Scanning Electron

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Ambient Variable Pressure Field Emission Scanning Electron Microscopy for Trichome Profiling of Plectranthus tomentosa by Secondary Electron Imaging

Applied Microscopy ◽

10.9729/am.2013.43.1.34 ◽

2013 ◽

Vol 43 (1) ◽

pp. 34-39 ◽

Cited By ~ 4

Author(s):

Ki Woo Kim

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Field Emission ◽

Secondary Electron ◽

Pressure Field ◽

Variable Pressure ◽

Electron Imaging ◽

Scanning Electron

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Delamination Behavior of Cu-Low-k Stack Under Different Slurries

MRS Proceedings ◽

10.1557/proc-767-f7.3 ◽

2003 ◽

Vol 767 ◽

Author(s):

A. K. Sikder ◽

S. Thagella ◽

P. B. Zantye ◽

Ashok Kumar

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Chemical Mechanical Polishing ◽

Wear Behavior ◽

Polished Surface ◽

Cu Metallization ◽

Wide Range ◽

Low K ◽

Delamination Behavior ◽

Scanning Electron

AbstractLower mechanical strength, reduced cohesive strength and lack of compatibility with other interconnect materials, are the major challenges involved in chemical mechanical polishing (CMP) of Cu metallization with ultra low-k materials as interlayer dielectrics. In this study we have investigated the polishing behavior of patterned Cu samples with underneath different low-k materials using two different slurries and a wide range of machine parameters. CMP micro tribometer was used to polish the samples with different rotations of platen (50 to 250 RPM) and down forces (1-6 PSI). Friction co-efficient and wear behavior were also investigated at different conditions. Optical and scanning electron microscopy was used to investigate the polished surface. It was observed that the two different Cu slurries used for polishing have marked effects on the polishing of Cu-low-k stack with respect to wear and delamination.

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Asbestos fiber identification in liver from cholangiocarcinoma patients living in an asbestos polluted area: a preliminary study

Tumori Journal ◽

10.1177/0300891619839305 ◽

2019 ◽

Vol 105 (5) ◽

pp. 404-410 ◽

Cited By ~ 2

Author(s):

Federica Grosso ◽

Alessandro Croce ◽

Roberta Libener ◽

Narciso Mariani ◽

Massimo Pastormerlo ◽

...

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Asbestos Exposure ◽

Optical Microscope ◽

Variable Pressure ◽

Chrysotile Asbestos ◽

Neoplastic Tissue ◽

Asbestos Fibers ◽

Preliminary Study ◽

Scanning Electron

Purpose: To assess whether asbestos fibers may be observed in liver tissue of patients with cholangiocarcinoma (CC) with environmental or working asbestos exposure. Methods: Detection of fibers was performed directly on histologic sections of liver from 7 patients with CC using optical microscope and variable pressure scanning electron microscopy equipped with energy-dispersive spectroscopy (VP-SEM/EDS). All patients were from Casale Monferrato, Italy, a highly asbestos-polluted town. Due to ethical constraints, observers were blinded to patients’ clinical features. Results: Fibers/bundles of fibers of chrysotile were detected in 5 out of 7 patients (71%). The boundary between healthy and neoplastic tissue or the fibrocollagen tissue produced by the neoplasia were identified as areas of fiber incorporation. Conclusions: This study is the first report about the detection of chrysotile asbestos fibers in the liver of patients with CC. Further studies on larger cohorts are needed to corroborate our preliminary findings.

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