scholarly journals Theoretical and experimental analysis of multifunctional high performance cement mortar matrices reinforced with varying lengths of carbon fibers

2018 ◽  
Vol 68 (332) ◽  
pp. 172
Author(s):  
R. A. Khushnood ◽  
S. Muhammad ◽  
S. Ahmad ◽  
J. M. Tulliani ◽  
M. U. Qamar ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Carbon Fibers ◽  
High Performance ◽  
Cement Mortar ◽  
Substantial Improvement ◽  
Fracture Properties ◽  
Plastic Shrinkage ◽  
Conducting Mechanism ◽  
Long Carbon Fibers ◽  
Scanning Electron

An effective scheme to formulate high performance and multifunctional cement based mortar composites reinforced with varying lengths of carbon fibers has been devised. The detailed investigations pertaining to the fracture response of composites in cracks initiation and progression phases, their conducting mechanism and volumetric stability were performed with varying loads of 6mm and 12mm long carbon fibers at two different w/c ratios i.e. 0.45 and 0.50. The experiments concluded that an optimum addition of carbon fibers results in substantial improvement of fracture properties alongside significant reduction in electrical resistivity and total plastic shrinkage. The field emission scanning electron microscopy of the cryofractured specimen revealed crack arresting actions of uniformly distributed carbon fibers through successful crack bridging and branching phenomenon.

The bright future of digital imaging in scanning electron microscopy

1993 ◽  
Vol 51 ◽  
pp. 768-769
Author(s):  
M. T. Postek ◽  
A. E. Vladar
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Digital Imaging ◽  
High Speed ◽  
High Performance ◽  
Mass Storage ◽  
Analog To Digital ◽  
Central Processing ◽  
Digital Imaging Technology ◽  
Scanning Electron

One of the major advancements applied to scanning electron microscopy (SEM) during the past 10 years has been the development and application of digital imaging technology. Advancements in technology, notably the availability of less expensive, high-density memory chips and the development of high speed analog-to-digital converters, mass storage and high performance central processing units have fostered this revolution. Today, most modern SEM instruments have digital electronics as a standard feature. These instruments, generally have 8 bit or 256 gray levels with, at least, 512 × 512 pixel density operating at TV rate. In addition, current slow-scan commercial frame-grabber cards, directly applicable to the SEM, can have upwards of 12-14 bit lateral resolution permitting image acquisition at 4096 × 4096 resolution or greater. The two major categories of SEM systems to which digital technology have been applied are:In the analog SEM system the scan generator is normally operated in an analog manner and the image is displayed in an analog or "slow scan" mode.

scholarly journals Boosting the Adhesivity of π-Conjugated Polymers by Embedding Platinum Acetylides towards High-Performance Thermoelectric Composites

Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 593 ◽  
Author(s):  
Tao Wan ◽  
Xiaojun Yin ◽  
Chengjun Pan ◽  
Danqing Liu ◽  
Xiaoyan Zhou ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Conjugated Polymers ◽  
High Performance ◽  
Single Walled Carbon Nanotubes ◽  
Strong Interactions ◽  
Transmission Electron ◽  
Higher Power ◽  
Walled Carbon Nanotubes ◽  
Scanning Electron

Single-walled carbon nanotubes (SWCNTs) incorporated with π-conjugated polymers, have proven to be an effective approach in the production of advanced thermoelectric composites. However, the studied polymers are mainly limited to scanty conventional conductive polymers, and their performances still remain to be improved. Herein, a new planar moiety of platinum acetylide in the π-conjugated system is introduced to enhance the intermolecular interaction with the SWCNTs via π–π and d–π interactions, which is crucial in regulating the thermoelectric performances of SWCNT-based composites. As expected, SWCNT composites based on the platinum acetylides embedded polymers displayed a higher power factor (130.7 ± 3.8 μW·m−1·K−2) at ambient temperature than those without platinum acetylides (59.5 ± 0.7 μW·m−1·K−2) under the same conditions. Moreover, the strong interactions between the platinum acetylide-based polymers and the SWCNTs are confirmed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) measurements.

scholarly journals The Bright Future of Digital Imaging in Scanning Electron Microscopy

1994 ◽  
Vol 2 (4) ◽  
pp. 19-20 ◽  
Author(s):  
M.T. Postek ◽  
A.E. Vladar
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Digital Imaging ◽  
High Speed ◽  
High Performance ◽  
Mass Storage ◽  
Analog To Digital ◽  
Central Processing ◽  
Digital Imaging Technology ◽  
Scanning Electron

One of the major advancements applied to scanning electron microscopy (SEM) during the past 10 years has been the development and application of digital imaging technology. Advancements in technology, notably the availability of less expensive, high-density memory chips and the development of high speed analog-to-digital converters, mass storage and high performance central processing units have fostered this revolution. Today, most modern SEM instruments have digital electronics as a standard feature. These instruments, generally have 8 bit or 256 gray levels with, at least, 512 X 512 pixel density operating at TV rate. In addition, current slow-scan commercial frame-grabber cards, directly applicable to the SEM, can have upwards of 12-14 bit lateral resolution permitting image acquisition at 4096 X 4096 resolution or greater.

Study the Effect of HAp Content in PLA/HAp Microsphere on the Efficiency of Drug (Clindamycin) Loading Process

2013 ◽  
Vol 834-836 ◽  
pp. 559-562 ◽  
Author(s):  
Juntima Pradid ◽  
Wirunya Keawwattana ◽  
Siree Tangbunsuk
Keyword(s):  
Electron Microscopy ◽  
Thermal Process ◽  
High Performance ◽  
Core Shell ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ultrasound Field ◽  
Sample Characterization ◽  
Core Shell Structure ◽  
Scanning Electron

An ultrasound field was applied to obtain Polylactic acid (PLA)/Hydroxyapatite (HAp) biocomposite microspheres with the specific core-shell structure to be applied as a carrier of a drug. The hydroxyapatite was obtained from crocodile bone by thermal process. Sample characterization was achieved by powder X-ray diffraction (XRD), Energy-dispersive X-ray spectroscopy (EDX) Scanning electron microscopy (SEM) and High Performance Liquid Chromatography (HPLC). As the result, the PLA/HAp loading clindamycin with different polymer-to-ceramic part wt.% ratio (100:0, 90:10, 80:20, and 70:30) showed the agglomeration of sphere-like particles. In addition, the loading efficiency of clindamycin increased with increasing HAp content up to 20%.

Effect of Latex Film Distributions on Flexibility of Redispersible Polymer Powders Modified Cement Mortar Evaluated by SEM

2015 ◽  
Vol 1129 ◽  
pp. 331-338 ◽  
Author(s):  
Guo Rong Zhao ◽  
Pei Ming Wang ◽  
Guo Fang Zhang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cement Mortar ◽  
Film Formation ◽  
Latex Film ◽  
Single Particles ◽  
Cement Pastes ◽  
Scanning Electron ◽  
Polymer Powders

Effect of latex film distributions on flexibility of redispersible polymer powders modified cement mortar were evaluated by scanning electron microscopy (SEM). Latex film distributions such as forming interpenetrated networks embedded in cement pastes, covering cement hydrates locally, bonding cement hydrates together, bridging aggregates were all beneficial for the improvement of flexibility of cement mortar. Latex film distributions such as remaining single particles in cement mortar, completing film formation unsuccessfully, film formation on surfaces of aggregates, bonding cement minerals to surfaces of aggregates may contribute little to the improvement of flexibility of cement mortar.

scholarly journals Synthesis and Characterization Molecularly Imprinted Polymers for Analysis of Dimethylamylamine Using Acrylamide as Monomer Functional

2018 ◽  
pp. 76-84
Author(s):  
Saeful Amin ◽  
Sophi Damayanti ◽  
Slamet Ibrahim
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
High Performance ◽  
Size Structure ◽  
Imprinted Polymer ◽  
Morphological Form ◽  
Molecularly Imprinted ◽  
Scanning Electron

A selective separation techniques with Molecularly Imprinted Polymer (MIP) for High-Performance Liquid Chromatography (HPLC) has been developed for the assay of Dimethylamylamine (DMAA) doping compounds. Molecular imprinted polymer (MIP) is a technique to produce a polymer having the cavity due to the disposal of the templates, in which the cavity serves to recognize the molecules of the same size, structure, chemical and physical properties. The selectivity and affinity of the templates itself will increase, while the concentration value is increasing. MIP is made by DMAA as template, acrylamide as functional monomer, ethylene glycol dimethacrylate (EGDMA) as cross linking, azobisisobutyronitrile (AIBN) as the initiator and chloroform as a porogen solvent; using bulk method. The aim of research are conduct the MIP for the DMAA compound analysis, then the formed MIP is characterized by using Fourier Transform Infra Red (FTIR) and Scanning Electron Microscopy (SEM) to find out the polymer complexes formed and the morphological form of the MIP. The MIP formed then was analyzed by using High-Performance Liquid Chromatography (HPLC) to know the amount of the DMAA, the adsorption capacity, and the adsorption condition found in the MIP. The result of analysis on the content of DMAA in the MIP by using UV-Vis Spectrophotometer is 1.957 mg. Scanning Electron Microscopy (SEM) shows that the MIP has irregular and rough morphological structure; while the NIP has irregular morphology structures and smooth surfaces shape

scholarly journals Wettability of Copper Coated Carbon Fibers

1994 ◽  
Vol 3 (4) ◽  
pp. 096369359400300
Author(s):  
G. Carotenuto ◽  
A. Gallo ◽  
L. Nicolais
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Carbon Fiber ◽  
Carbon Fibers ◽  
Solid Surface ◽  
Fiber Surface ◽  
Wetting Kinetics ◽  
Coated Carbon ◽  
Kinetics Of ◽  
Scanning Electron

The wetting kinetics of a solid surface by a molten metal decrease with increase of its roughness. The topography of the growing copper coating, produced on carbon fiber surface by electroplating from a sulphat bath, has been studied by scanning electron microscopy. The smoothes surface is produced after 200÷300 milliampere-hour of plating.

High resolution Scanning Electron Microscopy

1989 ◽  
Vol 47 ◽  
pp. 6-7
Author(s):  
David C. Joy
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
High Resolution ◽  
High Performance ◽  
Secondary Electron ◽  
Wide Energy Range ◽  
Wide Energy ◽  
Electron Microscopes ◽  
Electron Imaging ◽  
Scanning Electron

High resolution scanning electron microscopy is still a relatively new and unfamiliar concept because in the early days of the SEM it was expected, that secondary electron imaging would be limited to a resolution of between 5 and 10nm at best. Now, however, because of improvements in instrumentation and technique based on advances in the understanding of electron beam interactions with solids current SEMs can demonstrate spatial resolutions below 1nm, rivaling those obtained by transmission instruments.High performance scanning electron microscopes always incorporate two advanced items of instrumentation. Firstly they use field emission guns (FEGs). The high brightness, low energy spread, and small source size of the FEG makes it possible to produce an electron probe of sub-nanometer size which contains sufficient current for secondary electron imaging (i.e 10-12 amps or more) and which can maintain this performance over a wide energy range (3 to 30keV). Secondly, the new high performance instruments place the specimen within a high excitation, immersion, probe forming lens.

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