Papers by Keyword: Microscopic Observation

Abstract: The study was to find low costs and superior performance immobilized carrier for microorganism cells using in industry. Ca-alginate , Agar , Gelatin-glutaraldehyde and polyvinyl alcohol (PVA) were investigated to immobilize Saccharomyces cerevisiae cells, and immobilized cells’ production capacity for ethanol, contents of ethanol and mechanical strength were also studied. Then, optical microscope picture and scanning electronic microscope pictures were given to research its microenvironment. Finally, Batch and Continuous fermentation with PVA immbiolized Saccharomyces cerevisiae were experimented. The PVA immobilized method is the best in the four methods with concentration of 8%, microscopic observation also offered a proof that PVA material was fit for immobilizing cells with the traits of polycellular and reticulate. At last, the production capacity for ethanol and reactivity were superior to free cells in batch and continuous fermentation. This research could provide important information on the commercial utilization immobilized-cells for biotransformation.

Abstract: Growth kinetics of TBAB semiclathrate forming from 32wt% aqueous solution at 10±1°C and atmospheric pressure was studied through macro concentration determination and microscopic observation. The varied concentration from which the hydrate formed was measured in the range of 32wt% ~ 24wt% by means of weighting method, based on which three-stage hydration process was proposed. The morphology of TBAB hydrate crystals and growing velocity were then investigated based on a microscopic observation system. Coexistent morphology of TBAB semiclathrate hydrate crystals was obtained for the first time, with the single crystals in tetragonous, hexagonous, and octagonous columnar shapes. In the kinetics analysis, the growth velocity of TBAB semiclathrate hydrate crystals was calculated. Equation of the crystal growth for tetragonous and octagonous columnar crystals was worked out in combination of the varied concentration and the growth velocity. And to our best knowledge, no kinetics formula has been reported on the two shapes of TBAB semiclathrate hydrate crystals.

Abstract: The present paper investigates relationships between the macroscopic viscoplasticity and the surface morphological changes at room temperature for commercially pure titanium (CP-Ti) and austenitic stainless steel (SUS316L). Pure tensile test and tension-intermittent creep test are conducted. Both CP-Ti and SUS316L are deformed up to 16% of inelastic strain with a few unloading, and surface conditions are observed during pure tension test and tension-intermittent creep test. Qualitative surface observations and quantitative surface roughness measurements are made for the unloaded specimens. The surface roughness measurement shows that the curves plotted between surface roughness and inelastic strains are almost linear for all the present experiments. The slopes of curves depend, however, on material and type of tests, and this tendency agrees well with the qualitative surface observations by an optical microscope. The experimental results for CP-Ti suggest that different deformation mechanisms during tensile loading and creep contribute to different surface morphological changes.

Abstract: Surface microgrinding of the nanostructured WC/12Co coatings have been undertaken with diamond wheels under various conditions. Nondestructive and destructive approaches were utilized to assess damage in ground nanostructured coatings. Different surface and subsurface configurations were observed by scanning electron microscopy. This paper investigates the effects of microgrinding conditions on damage formation in the surface and subsurface layers of the ground nanostructured WC/12Co coatings. And the material-removal mechanism has been discussed.