Papers by Keyword: Scanning Electron Microscope (SEM)

Abstract: This paper presents the cathodic protection of steel embedded concrete of aluminum based alloy in brackish mud. In this experiment, aluminum based alloys containing 5% zinc, 2% magnesium, and 0.5-2% stannum were fabricated. These elements were added because they produce heat treatable alloys, improved anti friction characteristics, fluidibility, and contain highest strengthening effect on aluminum alloys. These alloys were tested as sacrificial cathodic protection for the standard steel embedded concrete exposed to sea water and brackish mud. Surface morphology of the samples after subjected to corrosion was investigated through scanning electron microscopy (SEM) and anode capacity test (efficiency test). The results revealed that sample with the composition of 95.6% of aluminum, 3.83% of zinc, and 0.19% of stannum showed the best performance hence it was selected for cathodic protection in brackish mud.

Abstract: The effect of untreated and treated (chromium sulfate and sodium bicarbonate) kenaf (KNF) on the water uptake and morphological properties of linear low density polyethylene/poly(vinyl alcohol)/kenaf (LLDPE/PVOH/KNF) composites was studied. The composites were prepared by using an internal mixer (Haake Polydrive) at 150 °C and 50 rpm for 10 min. The results showed that the untreated composites tend to absorb greater amount of water compared to the treated composites. This shows that the chromium sulfate and sodium bicarbonate treatment on KNF had improved the interfacial adhesion between KNF and LLDPE/PVOH matrices. Consequently, the capability of water absorption by the treated composites was reduced. Scanning electron microscope (SEM) result shows that lesser traces of filler pull-out and better filler-matrix interfacial adhesion were observed in the tensile fractured surfaces of treated composites.

Abstract: The aim of this work is to study the influence of carbon nanotubes in the cement matrix of high performance concrete (HPC) on flexural and compressive strength. This paper describes the samples preparation for the flexural and compression experimental tests. In order to understand the effect of carbon nanotubes in the cement matrix, a scanning electron microscope (SEM) analysis was carried out. It was reported after experimental tests that an improper dispersion of nanoparticles can have a negative influence on the mechanical properties. The dispersion of carbon nanotubes in the cement matrix is the most important aspect in order to attain the predicated influence on the mechanical properties.

Abstract: Electron beam irradiation is a chemical technology which mainly applies to food irradiation preservation, radiation sterilization of medical supplies, radiation chemistry and so on. It can change the molecular structure by using the radioactive radiation. In this present study, soybean protein concentrate powder was treated by electron beam irradiation to investigate its effects on the DH, the peptide antioxidant activity and the microcosmic surface morphology. The results indicated that the electron beam irradiation did not have effect on the DH. However, the peptide antioxidant activity significantly increased when increasing the irradiation dose. The highest peptide antioxidant activity 56.84 % was obtained at 3.24 kGy. Scanning electron microscope (SEM) revealed that there were a number of changes to the microcosmic surface morphology after the electron beam irradiation. Not only the shape of the soybean protein concentrate powder particles was changed, but the surface state was changed as well.

Abstract: In this study, the brand name 35CS300 and 50CS400 electromagnetic steel with tensile and high cycle fatigue properties were investigated. The specimens were prepared in rolling and transverse directions. In the first, the material basic properties were built from tensile test. The high cycle fatigue was performed under stress ratio 0.1 and two sampling direction. The tensile result showed that the specimens in rolling direction (L) are slight greater than in transverse direction (T). About the fatigue test results, the 35CS300 and 50CS400 sampling direction had less effect in fatigue limit. The fracture mechanism was showed that 35CS300 has void and brush like pull out under ductile failure. But the results showed in the 50CS400 specimens had splitting fracture surface with brittle fractograph. The electromagnetic steel surface of the insulating layer under dynamic fatigue loading would cause fragmentation; if the electromagnetic steel for long-term use will reduce the efficiency.

Abstract: The electropolishing behavior of high-purity aluminum in perchloric acid ethanol electrolytes is studied by the electrochemical methods. The morphologies of electropolished surface are examined by SEM. The results of anodic polarization shows that the limiting current density was decreased with the 1,2-propylene glycol and perchloric acid volume ratio increasing and the temperature decreasing. The results of SEM show that A salt film with porous pores on the electropolishing surface was formed on high-purity aluminum in the mixed solution of 1, 2 propylene glycol and perchloric acid at the volume ratio of 4:1 and 6:1, porosity of film increases from 12.3 % to18.4%, and the pore diameter of film increases from 19 nm to 23 nm with the current density increased from 120 mAcm^-2 to 140 mAcm^-2.

Abstract: In the present study, the effect of N, Ta and Co addition to near-α Ti-Al-Sn-Zr based alloy, on mechanical properties and microstructure has been investigated. Mechanical properties were investigated based on compression test at room temperature and at 650°C. Microstructure was investigated using optical microscope and scanning electron microscope. The results showed that addition of N, Ta and Co improved room temperature compressive strength. The strength improvement is mainly due to precipitation hardening mechanisms. At 650°C, only N addition improved compressive strength. The results were discussed based on the microstructure observation.

Abstract: Recently, in pharmaceutical research and industry scientists widely have used polysaccharides and other cationic polymer which is one of the most extensive studies in the field of non-viral DNA carriers for gene delivery and therapy. As a purpose of present study variations of the final solution pH values and filtration were examined for their effects on the particle size and the tendency of particle formation. Chitosan nanoparticles were prepared based on the ionic gelatin of chitosan which hydroxyapatite will adsorb onto the chitosan nanoparticles to form complexes of chitosan and hydroxyapatite. The resulting nanoparticles had a size and positive electrical charge, which vary depending on the formulation conditions. The physicochemical properties of the nanoparticles were determined by scanning electron microscope (SEM). Besides of that, element and chemical characterization of samples were assessed by Energy-dispersive X-ray spectroscopy (EDX). The data revealed that the chitosan/DNA nanoparticles were successfully prepared with a nanosize range. Obtained complexes could be loaded by variants of DNA for further use in gene delivery applications.

Abstract: It’s quite often that dispensing a topping material like concrete crystalline penetration sealer materials onto the surface of a plastic substance such as concrete to extend its service life span by surface protections from outside breakthrough. When applied to concrete it reacts with calcium hydroxide and reduces the porosity and permeability of the concrete matrix. This serves to increase the hardness and chemical resistance which, in turn, increases the service life span of the surface. A series of tests, such as rapid chloride permeability test, scanning electron microscope, and mercury intrusion porosimetry, were performed on the concrete test samples to examine the durability, by taking the penetration depth of concrete crystalline penetration sealer materials as a characterization parameter describing the durability in relation to water resistance. The penetration depth is a critical property for concrete crystalline penetration sealer materials to function effectively. The deeper the penetration, the greater the thickness of concrete strengthened, thus improving wear resistance, the life span and durability. The desirable depth drawn from tests is about 10mm with a minimum of 5mm. However the regular attainment of such penetration will require considerable care in surface preparation and in assuring that the concrete is properly dry. The quality of the concrete will also be a major factor in the depth of penetration obtained. Penetration depths may be greater with poor quality porous concrete while a 10mm depth may not be possible with high-quality dense concrete. Other Factors affecting concrete sealer penetration depth are related to the process, such as coverage and application, a user who should understand how it works, and material itself, having its own image.

Abstract: CNC turning is one among the metal cutting process in which quality of the finished product depends mainly upon the machining parameters such as feed, speed, depth of cut, type of coolant used, types of inserts used etc. Similarly the work piece material plays an important role in metal cutting process. This study involves in indentifying the optimized parameters in CNC turning of Brass. To identify and measure the formation of burrs in the turned samples, are examined under scanning electron microscope (SEM). The optimization techniques used in this study are Response surface methodology, and Genetic algorithm. Several comparisons were made between cutting parameters with surface roughness. These optimization techniques are very helpful in indentifying the optimized control factors with high level of accuracy.