scholarly journals Fiber statistics of nonwoven materials by SEM images - influence of number of images

2021 ◽  
Vol 7 (2) ◽  
pp. 652-655
Author(s):  
Andreas Götz ◽  
Niels Grabow ◽  
Sabine Illner ◽  
Volkmar Senz
Keyword(s):  
Electron Microscopy ◽  
Fiber Diameter ◽  
Edge Length ◽  
Sem Images ◽  
Nonwoven Materials ◽  
Gaussian Fit ◽  
Image Area ◽  
Sem Imaging ◽  
Minimum Surface Area ◽  
Scanning Electron

Abstract Electrospun nonwovens are widely applied in biomedicine and various other fields. For control of the manufacturing process and quality assurance Scanning electron microscopy (SEM) imaging is one standard practice. In this study, statistical datasets of 60 SEM images of three nonwoven samples were evaluated using Gaussian fit to obtain numerical results of their fiber diameter distributions. The question of how much effort is required for acceptable imaging and processing is being discussed. As determined here, for reliable statistics, a minimum surface area of the nonwoven has to be evaluated. The fiber diameter should be in a range of approximately 2 - 3% of the edge length of the square equivalent of the evaluated image area, using sufficiently magnified SEM images, in which the fiber diameter is imaged over at least 30 pixels.

scholarly journals Automated Fiber Diameter and Porosity Measurements of Plasma Clots in Scanning Electron Microscopy Images

Biomolecules ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1536
Author(s):  
Ali Daraei ◽  
Marlien Pieters ◽  
Stephen R. Baker ◽  
Zelda de Lange-Loots ◽  
Aleksander Siniarski ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Fiber Diameter ◽  
Structural Features ◽  
Fibrin Clot ◽  
Depth Of Field ◽  
Pixel Size ◽  
Sem Images ◽  
Highly Correlated ◽  
Scanning Electron

Scanning Electron Microscopy (SEM) is a powerful, high-resolution imaging technique widely used to analyze the structure of fibrin networks. Currently, structural features, such as fiber diameter, length, density, and porosity, are mostly analyzed manually, which is tedious and may introduce user bias. A reliable, automated structural image analysis method would mitigate these drawbacks. We evaluated the performance of DiameterJ (an ImageJ plug-in) for analyzing fibrin fiber diameter by comparing automated DiameterJ outputs with manual diameter measurements in four SEM data sets with different imaging parameters. We also investigated correlations between biophysical fibrin clot properties and diameter, and between clot permeability and DiameterJ-determined clot porosity. Several of the 24 DiameterJ algorithms returned diameter values that highly correlated with and closely matched the values of the manual measurements. However, optimal performance was dependent on the pixel size of the images—best results were obtained for images with a pixel size of 8–10 nm (13–16 pixels/fiber). Larger or smaller pixels resulted in an over- or underestimation of diameter values, respectively. The correlation between clot permeability and DiameterJ-determined clot porosity was modest, likely because it is difficult to establish the correct image depth of field in this analysis. In conclusion, several DiameterJ algorithms (M6, M5, T3) perform well for diameter determination from SEM images, given the appropriate imaging conditions (13–16 pixels/fiber). Determining fibrin clot porosity via DiameterJ is challenging.

scholarly journals Development of a New cryo-S(T)EM Technique Allowing Simultaneous STEM and SEM Imaging and its Application to Biological Samples

2021 ◽  
Author(s):  
Jiro Usukura ◽  
Akihiro Narita ◽  
Tomoharu Matsumoto ◽  
Eiji Usukura ◽  
Takeshi Sunaoshi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Surface Scanning ◽  
Sem Images ◽  
Cryo Electron Microscopy ◽  
Transmission Electron ◽  
Em Method ◽  
New Type ◽  
Sem Imaging ◽  
Spatial Architecture ◽  
Scanning Electron

Abstract A new type of cryo-electron microscopy (cryo-S(T)EM) technique made possible by installing a new cryo-transfer holder and an anti-contamination trap on a scanning electron microscope (Hitachi SU9000) allowed simultaneous collection of both transmission (transmission electron microscopy, TEM) images and surface (scanning electron microscopy, SEM) images at -180°C. The ultimate temperatures of the cryo-transfer holder and the anti-contamination trap reached − 190°C and − 210°C, respectively, by applying a liquid nitrogen slush. The TEM images obtained by the new cryo-S(T)EM method showed quality equal or superior to that of images obtained by conventional 100 kV TEM, although the resolution did not improve at -180°C due to slight drifting of the sample stage. Cryo-S(T)EM also had the unexpected advantage of enabling observations of intracellular structures in thick frozen cells by accelerating the sublimation of ice surrounding the specimens. The spatial architecture of the cytoskeleton, poly-ribosome-chains, endoplasmic reticulum (ER), mitochondria, etc., became visible in thick frozen cells via sufficient (deep) sublimation of ice in combination with the unroofing method. In particular, it should be noted that the ER appeared as a wide and flat structure beneath the cell membrane while forming a large spatial network together with tubular ER.

scholarly journals Investigation of the Fiber, Bulk, and Surface Properties of Meltblown and Electrospun Polymeric Fabrics

2004 ◽  
Vol os-13 (3) ◽  
pp. 1558925004os-13
Author(s):  
Peter P. Tsai ◽  
WeiWei Chen ◽  
J. Reece Roth
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Fiber Diameter ◽  
Electrospinning Process ◽  
Electrospun Fibers ◽  
Microscopic Structure ◽  
Electrospun Nanofiber ◽  
Sem Images ◽  
Nylon Fabric ◽  
Scanning Electron

We measured and compared the properties of meltblown and electrospun fabrics made of nylon and polyurethane (PU). Properties of interest included surface energy/wettability, strength, fiber diameter, and microscopic structure as revealed by scanning electron microscopy (SEM). We also report new data on the diameters of electrospun fibers measured from digitized SEM images of electrospun nylon, polyurethane (PU), polyacrylonitrile (PAN), polycaprolactone (PCL), and polycarbonate (PC) fabrics. The electrospinning process produced fibers with diameters in the range from 10 nm to several microns. It was found that the strength per unit areal weight of electrospun nanofiber nylon fabric was up to ten times that of the meltblown material, and for polyurethane (PU) fabric, from 2.5–3 times that of the melt-blown material.

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

Biology ◽  
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.

scholarly journals Apolar Bioactive Fraction ofMelipona scutellarisGeopropolis onStreptococcus mutansBiofilm

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Marcos Guilherme da Cunha ◽  
Marcelo Franchin ◽  
Lívia Câmara de Carvalho Galvão ◽  
Bruno Bueno-Silva ◽  
Masaharu Ikegaki ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Biofilm Formation ◽  
Microbial Population ◽  
Ethanolic Extract ◽  
Vehicle Control ◽  
Sem Images ◽  
Killing Assay ◽  
Bioactive Fraction ◽  
Biofilm Matrix ◽  
Scanning Electron

The aim of this study was to evaluate the influence of the bioactive nonpolar fraction of geopropolis onStreptococcus mutansbiofilm. The ethanolic extract ofMelipona scutellarisgeopropolis was subjected to a liquid-liquid partition, thus obtaining the bioactive hexane fraction (HF) possessing antimicrobial activity. The effects of HF onS. mutansUA159 biofilms generated on saliva-coated hydroxyapatite discs were analyzed by inhibition of formation, killing assay, and glycolytic pH-drop assays. Furthermore, biofilms treated with vehicle control and HF were analyzed by scanning electron microscopy (SEM). HF at 250 μg/mL and 400 μg/mL caused 38% and 53% reduction in the biomass of biofilm, respectively, when compared to vehicle control (P<0.05) subsequently observed at SEM images, and this reduction was noticed in the amounts of extracellular alkali-soluble glucans, intracellular iodophilic polysaccharides, and proteins. In addition, theS. mutansviability (killing assay) and acid production by glycolytic pH drop were not affected (P>0.05). In conclusion, the bioactive HF of geopropolis was promising to control theS. mutansbiofilm formation, without affecting the microbial population but interfering with its structure by reducing the biochemical content of biofilm matrix.

A New Methodology to Analyze Instabilities in SEM Imaging

2014 ◽  
Vol 20 (6) ◽  
pp. 1625-1637 ◽  
Author(s):  
Catalina Mansilla ◽  
Václav Ocelík ◽  
Jeff T. M. De Hosson
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Digital Image Correlation ◽  
Field Emission ◽  
Digital Image ◽  
Image Correlation ◽  
Ion Milling ◽  
Sem Imaging ◽  
Successive Generations ◽  
Scanning Electron

AbstractThis paper presents a statistical method to analyze instabilities that can be introduced during imaging in scanning electron microscopy (SEM). The method is based on the correlation of digital images and it can be used at different length scales. It consists of the evaluation of three different approaches with four parameters in total. The methodology is exemplified with a specific case of internal stress measurements where ion milling and SEM imaging are combined with digital image correlation. It is concluded that before these measurements it is important to test the SEM column to ensure the minimization and randomization of the imaging instabilities. The method has been applied onto three different field emission gun SEMs (Philips XL30, Tescan Lyra, FEI Helios 650) that represent three successive generations of SEMs. Important to note that the imaging instability can be quantified and its source can be identified.

scholarly journals Analysis of the type material of Gomphosphenia tackei (Bacillariophyceae) and comparison to epizoic diatom populations on freshwater snails

2021 ◽  
Vol 154 (2) ◽  
pp. 257-263
Author(s):  
Mateusz Rybak ◽  
Łukasz Peszek ◽  
Anita Poradowska
Keyword(s):  
Electron Microscopy ◽  
Lymnaea Stagnalis ◽  
Morphological Characteristics ◽  
Small Cell ◽  
Type Material ◽  
Freshwater Snails ◽  
Sem Images ◽  
Small Cell Size ◽  
Type Population ◽  
Scanning Electron

Background and aims – Hustedt (1942) originally described Gomphosphenia tackei from Germany under the name Gomphonema tackei. Because of the small cell size and the lack of scanning electron microscopy (SEM) images from the type material, it is often confused with other species from this genus, especially with G. stoermeri. The aim of this paper was to present detailed morphological characteristics of G. tackei based on the analysis of the type material and of several epizoic populations from Central Europe. Material and methods – The material in this study was collected from the shells of the freshwater snails Lymnaea stagnalis, Planorbarius corneus, and Planorbis planorbis. Additionally, for an unambiguous species identification, the type material for Gomphosphenia tackei was analyzed using light and scanning electron microscopes.Key results – The presence of Gomphosphenia tackei was confirmed in the studied material. The largest population (up to 19%) was recorded on the shell surfaces of living snails, whereas on empty shells, the diatom did not seem to be present or only in very low numbers. Valves are typically clavate with rounded apices. Valves are frequently observed in girdle view, often joint together in pairs. The valves in the studied populations had a valve length of 7–29 µm, a valve width of 3–4 µm, and a stria density of 25–29 striae in 10 µm. In the type population, valve length ranged from 7.5 to 27 µm with a valve width of 3.0–4.0 µm and a stria density of 23–29 striae per 10 µm. Striae were composed of 2–4 elongated to rounded areolae per stria. At the apices, the striae were composed of one single areola. The cells were attached to the substratum by their footpole.Conclusion – Published illustrations of Gomphosphenia tackei do not always correctly represent this species. Individual cells are attached to the substratum by secreted mucilage, probably via their areolae or girdle band pores located on the footpole.

Fabrication of Ultra Thick Ferromagnetic Structures in Silicon

2004 ◽  
Author(s):  
Debbie G. Jones ◽  
Albert P. Pisano
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Scanning Electron Microscopy ◽  
Saturation Magnetization ◽  
Silicon Wafer ◽  
Fabrication Process ◽  
Sem Images ◽  
Deep Reactive Ion Etching ◽  
Scanning Electron

A novel fabrication process is presented to create ultra thick ferromagnetic structures in silicon. The structures are fabricated by electroforming NiFe into silicon templates patterned with deep reactive ion etching (DRIE). Thin films are deposited into photoresist molds for characterization of an electroplating cell. Results show that electroplated films with a saturation magnetization above 1.6 tesla and compositions of approximately 50/50 NiFe can be obtained through agitation of the electrolyte. Scanning electron microscopy (SEM) images show that NiFe structures embedded in a 500 μm thick silicon wafer are realized and the roughening of the mold sidewalls during the DRIE aids in adhesion of the NiFe to the silicon.

Biomimetic Crack Sensors Using Electrohydrodynamic Technology

2021 ◽  
Vol 21 (7) ◽  
pp. 3773-3778
Author(s):  
Keon-Young Kim ◽  
Se-Min Jeong ◽  
Chang-Yull Lee
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Crack Initiation ◽  
Health Monitoring ◽  
Grid Structure ◽  
Sem Images ◽  
Impact Tester ◽  
Microscopic Damage ◽  
Pet Substrate ◽  
Scanning Electron

This paper proposes a new mechanism for detecting microscopic damage of structures based on imitating the sensory organs of spiders. Therefore, it is essential to manufacture sensors that can react sensitively to the micro deformations of structures. Numerous cracks were intentionally generated to improve the sensitivity of the proposed sensor, and an increase in the gap of the crack was observed by scanning electron microscopy (SEM) observation. Electrohydrodynamic technology is used to detect deformations in a structure of depositing Ag nano paste on a polyethylene terephtha-late (PET) substrate. Ag nano lines are also observed by SEM images. The sensor is constructed as a grid structure, by forming layers patterned horizontally and vertically. An impact tester is used to verify the mechanism for structural health monitoring using the developed sensor. The resistance changes of the sensors are applied to estimate the structure’s damaged location. The intersections of the lines with varying resistance can be used to accurately detect crack initiation. The proposed mechanism is a powerful methodology for estimating and detecting microscopic deformations and damage to structures.

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