Mechanical and Microstructural Changes of Biocemented Sand Subjected to an Acid Solution

Author(s):  
Christian Geindreau ◽  
Fabrice Emeriault ◽  
Abdelali Dadda ◽  
Olatounde Yaba ◽  
Lorenzo Spadini ◽  
...  
Author(s):  
E. P. Abrahamson II ◽  
M. W. Dumais

In a transmission microscopy study of iron and dilute iron base alloys, it was determined that it is possible to preserve specimens for extended periods of time. Our specimens were prepunched from 5 to 8 mil sheet to microscope size and annealed for several hours at 700°C. They were then thinned in a glacial acetic-12 percent perchloric acid solution using 10 volts and 20 milliamperes, at a temperature of 8 to 14°C.It was noted that by the use of a cold stage, the same specimen can be observed for periods up to one week without excess contamination. When removal of the specimen from the column becomes necessary, it was observed that a specimen may be kept for later observation in 1,2 dichloroethene or methanol for periods in excess of two weeks.


Author(s):  
E. U. Lee ◽  
P. A. Garner ◽  
J. S. Owens

Evidence for ordering (1-6) of interstitial impurities (O and C) has been obtained in b.c.c. metals, such as niobium and tantalum. In this paper we report the atomic and microstructural changes in an oxygenated c.p.h. metal (alpha titanium) as observed by transmission electron microscopy and diffraction.Oxygen was introduced into zone-refined iodide titanium sheets of 0.005 in. thickness in an atmosphere of oxygen and argon at 650°C, homogenized at 800°C and furnace-cooled in argon. Subsequently, thin foils were prepared by electrolytic polishing and examined in a JEM-7 electron microscope, operated at 100 KV.


Author(s):  
Michio Ashida ◽  
Yasukiyo Ueda

An anodic oxide film is formed on aluminum in an acidic elecrolyte during anodizing. The structure of the oxide film was observed directly by carbon replica method(l) and ultra-thin sectioning method(2). The oxide film consists of barrier layer and porous layer constructed with fine hexagonal cellular structure. The diameter of micro pores and the thickness of barrier layer depend on the applying voltage and electrolyte. Because the dimension of the pore corresponds to that of colloidal particles, many metals deposit in the pores. When the oxide film is treated as anode in emulsion of polyelectrolyte, the emulsion particles migrate onto the film and deposit on it. We investigated the behavior of the emulsion particles during electrodeposition.Aluminum foils (99.3%) were anodized in either 0.25M oxalic acid solution at 30°C or 3M sulfuric acid solution at 20°C. After washing with distilled water, the oxide films used as anode were coated with emulsion particles by applying voltage of 200V and then they were cured at 190°C for 30 minutes.


Author(s):  
B. J. Hockey ◽  
S. M. Wiederhorn

ATEM has been used to characterize three different silicon nitride materials after tensile creep in air at 1200 to 1400° C. In Part I, the microstructures and microstructural changes that occur during testing were described, and consistent with that description the designations and sintering aids for these materials were: W/YAS, a SiC whisker reinforced Si3N4 processed with yttria (6w/o) and alumina (1.5w/o); YAS, Si3N4 processed with yttria (6 w/o) and alumina (1.5w/o); and YS, Si3N4 processed with yttria (4.0 w/o). This paper, Part II, addresses the interfacial cavitation processes that occur in these materials and which are ultimately responsible for creep rupture.


1967 ◽  
Vol 18 (01/02) ◽  
pp. 057-065 ◽  
Author(s):  
G Zbinden

SummaryIntravenous injection of 0.5% lauric acid solution into rabbits caused moderate to marked thrombocytopenia. With small doses (2.5 mg/kg) this thrombocyte decrease was reversible and microscopically demonstrable thrombosis in the lungs was only seen or suspected in a small number of rabbits 10 to 30 min after lauric acid injection. High doses were followed by partly reversible thrombocytopenia and by moderate to marked, sometimes lethal, thrombosis in the lungs still demonstrable 24 hrs after injection. Repeated administration of small doses of lauric acid did not lead to a depletion of the circulating thrombocytes. Thrombocytopenic response, however, appeared to be less pronounced after the second and subsequent injections. Studies with Cr51-labeled platelets indicate that during the reversible thrombocytopenia following a small intravenous dose of lauric acid platelets are retained in various organs, particularly the lungs.


2014 ◽  
Vol 52 (9) ◽  
pp. 721-729
Author(s):  
Seul Gi Hwang ◽  
Jeong Hyun Jo ◽  
Shang shu Kim ◽  
Young ho Lee ◽  
Jae Kwan Ku

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