Scanning electron microscope

The first scanning electron microscope (SEM) was invented by Manfred von Ardenne in 1937 (McMullan). However, further development of the SEM was accomplished by Charles Oatley and his colleagues at Cambridge University (McMullan; Egerton 17). He and his colleagues acquired their first images from the SEM in 1951 (Egerton 17). The SEM was developed because if a TEM is utilized, a specimen must be made extremely thin to prevent the electrons from dispersing inside the specimen and so the electrons are not absorbed. This was the foremost limitation of the TEM that truly motivated the development of the SEM (McMullan; Egerton 16, 17). The SEM displays the ultrastructure of the specimen, the images have a large depth of focus and shows the surface…

Technical Review of Hydrothermal Formation of Calcium Copper Tetrasilicate Introduction Scanning electron microscopy (SEM) is used to obtain close-up images of samples with depth enabling high quality, 3D depictions on a microscopic level. It has been historically used to identify samples of interest such as bacterial biofilm, microtexture surfaces, and even cancer cells for diagnosis.[1, 2, 3] The first high magnification SEM was reported in a journal in 1938 by Ardenne after developing the…

3.2 Analysis of chip formation Fig. 7 shows the chip forms obtained during milling of the Al7075 (a) and MMCs (b) using the uncoated carbide inserts at a feed rate of 0.1 mm/tooth, machining speed of 290 m/min and axial depth of cut of 1.3 mm. The Al7075 chips formed during milling exhibited a smooth and shiny surface, and were in a semicircular and parabolic trapezoidal wave with a small radius and a saw-tooth-form, as shown in Fig. 7 (a). Fig. 7 (b) shows the chip shapes formed during the…

The interior structure and size of the as-synthesized pure HA, Sr0.1HA, La0.1HA and La0.1Sr0.1HA nanoparticles are further confirmed from HRTEM analysis and the images are depicted in Fig. 5(a)-(d). The TEM results reveal that as-synthesized nanoparticles are formed spherical shaped nanoparticles ranging from 20 to 84nm. The interior morphology of La0.1Sr0.1HA (Fig. 5 (d)) is found to be clear spherical like with a size reduced to 20nm. Based on the micrograph of La/Sr-HA significantly reduced…

The diffraction pattern was scanned over 2 range of 3 to 50o at a scanning rate of 1o/min. The relative degree of crystallinity (RDC) was calculated to determine the degree of drug crystallinity in formulation compared to pure drug, by using the following equation18. (Maulvi et al., 2011) EXM…

2.4.1. Statistical Analyses: All the statistical analyses were done by using Design Expert© 9.0 (Stat-Ease, USA) software package program. Total 20 experimental studies were run to prepare porous scaffold and for each run % AP was calculated manually by use of Archimedes principle. The observed response values (% AP) then put into CCD model and generate a response surface image (Figure 2). After that, the numerical optimization was done by maintaining all parameter values “in range” and response…

weight of the powder sample was used to calculate the bulk density before tapping. Approximately after 100 taps/min (until no volume change) the volume was observed (tapped volume) and used to calculate the tapped density from powder weight. Moisture content by thermogravimetric analysis (TGA) The moisture contents of the supplied and spray-dried powders were determined using a thermogravimetric analyser (TA Instruments, New Castle, DE). After loading into a platinum sample pan, the powder…

Using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) images and spectra were obtained from various samples of silica and platinum on silica. Each sample contains unique structures which were prepared by etching the surface of silica in different conditions. A scanning electron microscope is a type of electron microscope that produces images of topography and composition by scanning a sample with a focused beam of electrons. Samples can be observed in high vacuum,…

proanthocyanidin extract (GSPE): Powdered grape seed proanthocyanidinextract (GSPE) commercially known as Noxylife was obtained from Pharco Pharmaceuticals (Alexandria, Egypt). -Sodium hydroxide, concentrated nitric acid, concentrated perchloric acid, Phosphate buffer 5mM and Dithionitrobenzoic acid 10 mM, (El-NASR, Pharmaceutical Chemicals Company, Cairo, Egypt). Thiobarbituric acid (TBA: 0.67%), Trichloroacetic acid (TCA: 20%), Tris/EDTA buffer 0.1M and Citrate buffer pH 6, N-butanol (Sigma,…

Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) are two very widespread techniques for examining various properties of substances in many fields of study. These fields can range from biology to chemistry to geology and several others (5). Both work by using the electromagnetic properties of the ways that electrons travel and interact with other atoms. Because electrons have a shorter wavelength of motion and a much higher energy than light, electron microscopy has a…