Test Specimens For High Resolution Scanning Electron Microscopy

1973 ◽  
Vol 31 ◽  
pp. 238-239
Author(s):  
Raymond T. Greer
Keyword(s):  
Electron Microscopy ◽  
Test Specimen ◽  
Low Cost ◽  
Silica Spheres ◽  
High Quality ◽  
Low Contrast ◽  
Long Term Stability ◽  
Closest Packing ◽  
Scanning Electron

A useful resolution specimen for day-to-day SEM instrument standardization should exhibit uniform, periodic microstructure of hundreds to thousands of angstroms, show low contrast, have low cost, be easily prepared, and demonstrate long term stability.Opal (Figure 1) is particularly useful as a resolution specimen; however, several aspects of sample preparation should be emphasized. A high quality gem opal chip a few millimeters in diameter is sufficient for carefully controlled etching in, for example, 10% HF for 30 seconds. The choice of test specimen microstructure size is established by the maximum wavelength of color observed under white light. The iridescence effect is dictated by the microstructure of uniform silica spheres arranged in a cubic closest packing array.

scholarly journals In Vitro Comparison of the Efficacy of Peri-Implantitis Treatments on the Removal and Recolonization of Streptococcus gordonii Biofilm on Titanium Disks

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2484 ◽  
Author(s):  
Selena Toma ◽  
Catherine Behets ◽  
Michel C. Brecx ◽  
Jerome F. Lasserre
Keyword(s):  
Electron Microscopy ◽  
Control Group ◽  
Streptococcus Gordonii ◽  
Long Term Stability ◽  
Dental Biofilm ◽  
Clinical Procedures ◽  
Scanning Electron ◽  
In Vitro Comparison

Objective: To compare the efficacy of four commonly used clinical procedures in removing Streptococcus gordonii biofilms from titanium disks, and the recolonization of the treated surfaces. Background: Successful peri-implantitis treatment depends on the removal of the dental biofilm. Biofilm that forms after implant debridement may threaten the success of the treatment and the long-term stability of the implants. Methods: S. gordonii biofilms were grown on titanium disks for 48 h and removed using a plastic curette, air-abrasive device (Perio-Flow®), titanium brush (TiBrush®), or implantoplasty. The remaining biofilm and the recolonization of the treated disks were observed using scanning electron microscopy and quantified after staining with crystal violet. Surface roughness (Ra and Rz) was measured using a profilometer. Results: S. gordonii biofilm biomass was reduced after treatment with Perio-Flow®, TiBrush®, and implantoplasty (all p < 0.05), but not plastic curette (p > 0.05), compared to the control group. Recolonization of S. gordonii after treatment was lowest after Perio-Flow®, TiBrush®, and implantoplasty (all p < 0.05 vs. control), but there was no difference between the plastic curette and the control group (p > 0.05). Ra and Rz values ranged from 1–6 µm to 1–2 µm and did not differ statistically between the control, plastic curette, Perio-Flow, and TiBrush groups. However, the implantoplasty group showed a Ra value below 1 µm (p < 0.01, ANOVA, Tukey). Conclusions: Perio-Flow®, TiBrush®, and implantoplasty were more effective than the plastic curette at removing the S. gordonii biofilm and preventing recolonization. These results should influence the surgical management of peri-implantitis.

Fluxless Microjoining by Au-In-Ni Isothermal Solidification

1999 ◽  
Vol 605 ◽  
Author(s):  
M. Waelti ◽  
N. Schneeberger ◽  
O. Brand ◽  
H. Baltes
Keyword(s):  
Electron Microscopy ◽  
Bonding Temperature ◽  
Optical Filter ◽  
High Strength ◽  
Isothermal Solidification ◽  
High Thermal Stability ◽  
Reflow Soldering ◽  
Long Term Stability ◽  
Scanning Electron

AbstractA reliable, fluxless microjoining technique based on isothermal solidification is reported. The Au-In-Ni system has been chosen for bonding, because gold is often applied for wafer bumping, and Ni is commonly used for substrate plating. To demonstrate the potential of this microjoining scheme, optical filter have been directly attached to a smart CMOS thermoelectric IR system. Since further packaging of the microsystem includes SMT assembly, the bond has to withstand subsequent SnPb reflow-soldering.The influence of bonding time and temperature on the bond was investigated. Phase formation and transformation were analyzed by light and scanning electron microscopy (SEM). Bonding performed at temperatures below 200°C remained stable even after multiple soldering cycles with peak temperatures of 235°C. The shear strength of the bonds was found to be more than 70 MPa. Long term stability was confirmed by extended anneal at 160°C. The method is generally well suited for processes involving sequences of joining steps, and for bonds demanding high strength and high thermal stability at low bonding temperature.

scholarly journals Wittichenite semiconductor of Cu3BiS3 films for efficient hydrogen evolution from solar driven photoelectrochemical water splitting

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Dingwang Huang ◽  
Lintao Li ◽  
Kang Wang ◽  
Yan Li ◽  
Kuang Feng ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Water Splitting ◽  
Low Cost ◽  
Solar Hydrogen ◽  
Onset Potential ◽  
Term Stability ◽  
Long Term Stability ◽  
Solar Water Splitting ◽  
Current Densities

AbstractA highly efficient, low-cost and environmentally friendly photocathode with long-term stability is the goal of practical solar hydrogen evolution applications. Here, we found that the Cu3BiS3 film-based photocathode meets the abovementioned requirements. The Cu3BiS3-based photocathode presents a remarkable onset potential over 0.9 VRHE with excellent photoelectrochemical current densities (~7 mA/cm2 under 0 VRHE) and appreciable 10-hour long-term stability in neutral water solutions. This high onset potential of the Cu3BiS3-based photocathode directly results in a good unbiased operating photocurrent of ~1.6 mA/cm2 assisted by the BiVO4 photoanode. A tandem device of Cu3BiS3-BiVO4 with an unbiased solar-to-hydrogen conversion efficiency of 2.04% is presented. This tandem device also presents high stability over 20 hours. Ultimately, a 5 × 5 cm2 large Cu3BiS3-BiVO4 tandem device module is fabricated for standalone overall solar water splitting with a long-term stability of 60 hours.

scholarly journals Digital Imaging: When Should One Take The Plunge?

1997 ◽  
Vol 5 (4) ◽  
pp. 14-15
Author(s):  
John F. Mansfield
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Optical Microscopy ◽  
Digital Imaging ◽  
High Quality ◽  
Storage Devices ◽  
Major Benefit ◽  
Transmission Electron ◽  
Scanning Electron

The current imaging trend in optical microscopy, scanning electron microscopy (SEM) or transmission electron microscopy (TEM) is to record all data digitally. Most manufacturers currently market digital acquisition systems with their microscope packages. The advantages of digital acquisition include: almost instant viewing of the data as a high-quality positive image (a major benefit when compared to TEM images recorded onto film, where one must wait until after the microscope session to develop the images); the ability to readily quantify features in the images and measure intensities; and extremely compact storage (removable 5.25” storage devices which now can hold up to several gigabytes of data).

scholarly journals Solvothermal Synthesis of Mn3O4Nanoparticle/Graphene Sheet Composites and Their Supercapacitive Properties

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Y. F. Liu ◽  
G. H. Yuan ◽  
Z. H. Jiang ◽  
Z. P. Yao
Keyword(s):  
Electron Microscopy ◽  
Graphene Sheet ◽  
Low Cost ◽  
High Specific Capacitance ◽  
Ethanol Solution ◽  
Diffraction Field ◽  
Electrochemical Performances ◽  
One Pot ◽  
Long Term Stability ◽  
Transmission Electron

Mn3O4nanoparticle/graphene sheet (GM) composites were synthesized via a one-pot and low-cost solvothermal process in an ethanol solution. The as-prepared materials were characterized by X-ray diffraction, field emission scanning electron microscopy, and transmission electron microscopy. Results showed that the nanosized Mn3O4particles had tetragonal hausmannite structure and were successfully loaded on the graphene sheets. Moreover, the electrochemical performances of GM composites produced by different mass percents of Mn2+/graphite oxide (GO) were evaluated by means of cyclic voltammetry and galvanostatic charge-discharge studies. The composite prepared with Mn2+/GO mass percent of 10 : 90 showed a high specific capacitance of 245 F/g at 5 mV/s in the 6 M KOH solution and better long-term stability along with 81% of its initial capacitance after 1200 cycles at 0.5 A/g.

scholarly journals Preparation and Characterization of PEBAX-5513/AgBF4/BMIMBF4 Membranes for Olefin/Paraffin Separation

Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1550 ◽  
Author(s):  
So Young Kim ◽  
Younghyun Cho ◽  
Sang Wook Kang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Poor Performance ◽  
Amide Group ◽  
Stabilizing Effect ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene ◽  
Scanning Electron

In this study, we investigated a poly(ether-block-amide)-5513 (PEBAX-5513)/AgBF4/1-butyl-3-methylimidazolium tetrafluoroborate (BMIMBF4) composite membrane, which is expected to have a high stabilizing effect on the Ag+ ions functioning as olefin carriers in the amide group. Poly(ethylene oxide) (PEO) only consists of ether regions, whereas the PEBAX-5513 copolymer contains both ether and amide regions. However, given the brittle nature of the amide, the penetration of BMIMBF4 remains challenging. The nanoparticles did not stabilize after their formation in the long-term test, thereby resulting in a poor performance compared to previous experiments using PEO as the polymer (selectivity 3; permeance 12.3 GPU). The properties of the functional groups in the polymers were assessed using Fourier transform infrared spectroscopy, scanning electron microscopy, and thermogravimetric analysis, which confirmed that the properties endowed during the production of the film using the ionic liquid can impact the performance.

Synthesis of Trilaminar Core–Shell Au/α-Fe2O3@SnO2Nanocomposites and their Application for Nonenzymatic Dopamine Electrochemical Sensing

NANO ◽  
2019 ◽  
Vol 14 (11) ◽  
pp. 1950138 ◽  
Author(s):  
Sai Zhang ◽  
Shijun Yue ◽  
Jiajia Li ◽  
Jianbin Zheng ◽  
Guojie Gao
Keyword(s):  
Electron Microscopy ◽  
High Sensitivity ◽  
Electrochemical Sensing ◽  
Synthesis Process ◽  
Core Shell ◽  
X Ray Diffraction ◽  
X Ray ◽  
Long Term Stability ◽  
Transmission Electron

Au nanoparticles anchored on core–shell [Formula: see text]-Fe2O3@SnO2 nanospindles were successfully constructed through hydrothermal synthesis process and used for fabricating a novel nonenzymatic dopamine (DA) sensor. The structure and morphology of the Au/[Formula: see text]-Fe2O3@SnO2 trilaminar nanohybrid film were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The electrochemical properties of the sensor were investigated by cyclic voltammetry and amperometry. The experimental results suggest that the composites have excellent catalytic property toward DA with a wide linear range from 0.5[Formula: see text][Formula: see text]M to 0.47[Formula: see text]mM, a low detection limit of 0.17[Formula: see text][Formula: see text]M (S/[Formula: see text]) and high sensitivity of 397.1[Formula: see text][Formula: see text]A[Formula: see text]mM[Formula: see text][Formula: see text]cm[Formula: see text]. In addition, the sensor exhibits long-term stability, good reproducibility and anti-interference.

scholarly journals Taxonomic synthesis of the eastern North American millipede genus Pseudopolydesmus (Diplopoda: Polydesmida: Polydesmidae), utilizing high-detail ultraviolet fluorescence imaging

2019 ◽  
Vol 187 (1) ◽  
pp. 117-142 ◽  
Author(s):  
Petra Sierwald ◽  
Derek A Hennen ◽  
Xavier J Zahnle ◽  
Stephanie Ware ◽  
Paul E Marek
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Fluorescence Imaging ◽  
North American ◽  
Type Material ◽  
High Quality ◽  
Subjective Synonym ◽  
Scanning Electron

Abstract The species of the eastern North American millipede genus Pseudopolydesmus are reviewed. Synonyms and comprehensive literature citations are provided for each of the eight recognized species. Diagnostic morphology of the genus, including clarification of male gonopod terminology, is reviewed and defined using scanning electron microscopy and high-quality macrophotographic images, including those in which ultraviolet fluorescence was induced to produce detailed images of morphological structures. Based on the examination of available type material, the following eight species are recognized: (1) Pseudopolydesmus erasus; (2) Pseudopolydesmus canadensis; (3) Pseudopolydesmus collinus; (4) Pseudopolydesmus pinetorum; (5) Pseudopolydesmus minor; (6) Pseudopolydesmus caddo; (7) Pseudopolydesmus paludicolus; and (8) Pseudopolydesmus serratus. The species names Polydesmus neoterus and Polydesmus euthetus are here placed as junior subjective synonyms of Ps. minor (both syn. nov.), and Polydesmus natchitoches is placed as a junior subjective synonym of Ps. pinetorum (syn. nov.).

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