Sorption of Pu(III-IV) Onto Tio2: A Preliminary Study

2002 ◽  
Vol 757 ◽  
Author(s):  
M. Olsson ◽  
H. Nilsson ◽  
A. M. Jakobsson ◽  
Y. Albinsson

ABSTRACTA preliminary study of the sorption of reduced plutonium (III-IV) onto TiO2 has been done under anoxic conditions at varying pH and ionic strength. The first approach was to study tetravalent Pu, but the sorption decreases with time in this case. This is probably due to disproportionation of Pu(IV) at the TiO2 surface, which then acts as a catalyst. A further observation that supports this explanation is that the sorption of Pu(IV) onto the walls of the experimental equipment is in some cases higher than the sorption of (disproportioned) Pu onto the oxide.Pu(III) sorption onto the oxide was also investigated and showed similarities with the previously investigated sorption of Pm(III) in a similar system.

2010 ◽  
Vol 47 (5) ◽  
pp. 431-438 ◽  
Author(s):  
Yoshihisa IIDA ◽  
Tetsuji YAMAGUCHI ◽  
Tadao TANAKA ◽  
Shinichi NAKAYAMA

2019 ◽  
Vol 6 (3) ◽  
pp. 261-264
Author(s):  
F. Guo ◽  
Y. Zhang ◽  
Z. Wang ◽  
X. Wang ◽  
H. Gao

In order to analyze the making arc characteristics of AgSnO<sub>2</sub> contact, experiments were carried out with a self-developed experimental equipment. It was found that contact resistance had no obvious change with the increase of the number of experiments.In the later stage of the experiment, the contact bounces occurred during the contact closing process, which not only prolonged the making arc duration, but also increased making arc energy. When the contact was eroded to a certain extent by arc, making welding occurs.


Author(s):  
John H.L. Watson ◽  
John L. Swedo ◽  
R.W. Talley

A preliminary study of human mammary carcinoma on the ultrastructural level is reported for a metastatic, subcutaneous nodule, obtained as a surgical biopsy. The patient's tumor had responded favorably to a series of hormonal therapies, including androgens, estrogens, progestins, and corticoids for recurring nodules over eight years. The pertinent nodule was removed from the region of the gluteal maximus, two weeks following stilbestrol therapy. It was about 1.5 cms in diameter, and was located within the dermis. Pieces from it were fixed immediately in cold fixatives: phosphate buffered osmium tetroxide, glutaraldehyde, and paraformaldehyde. Embedment in each case was in Vestopal W. Contrasting was done with combinations of uranyl acetate and lead hydroxide.


Author(s):  
F. Thoma ◽  
TH. Koller

Under a variety of electron microscope specimen preparation techniques different forms of chromatin appearance can be distinguished: beads-on-a-string, a 100 Å nucleofilament, a 250 Å fiber and a compact 300 to 500 Å fiber.Using a standardized specimen preparation technique we wanted to find out whether there is any relation between these different forms of chromatin or not. We show that with increasing ionic strength a chromatin fiber consisting of a row of nucleo- somes progressively folds up into a solenoid-like structure with a diameter of about 300 Å.For the preparation of chromatin for electron microscopy the avoidance of stretching artifacts during adsorption to the carbon supports is of utmost importance. The samples are fixed with 0.1% glutaraldehyde at 4°C for at least 12 hrs. The material was usually examined between 24 and 48 hrs after the onset of fixation.


Author(s):  
H.D. Geissinger ◽  
C.K. McDonald-Taylor

A new strain of mice, which had arisen by mutation from a dystrophic mouse colony was designated ‘mdx’, because the genetic defect, which manifests itself in brief periods of muscle destruction followed by episodes of muscle regeneration appears to be X-linked. Further studies of histopathological changes in muscle from ‘mdx’ mice at the light microscopic or electron microscopic levels have been published, but only one preliminary study has been on the tibialis anterior (TA) of ‘mdx’ mice less than four weeks old. Lesions in the ‘mdx’ mice vary between different muscles, and centronucleation of fibers in all muscles studied so far appears to be especially prominent in older mice. Lesions in young ‘mdx’ mice have not been studied extensively, and the results appear to be at variance with one another. The degenerative and regenerative aspects of the lesions in the TA of 23 to 26-day-old ‘mdx’ mice appear to vary quantitatively.


Author(s):  
J.S. Wall ◽  
V. Maridiyan ◽  
S. Tumminia ◽  
J. Hairifeld ◽  
M. Boublik

The high contrast in the dark-field mode of dedicated STEM, specimen deposition by the wet film technique and low radiation dose (1 e/Å2) at -160°C make it possible to obtain high resolution images of unstained freeze-dried macromolecules with minimal structural distortion. Since the image intensity is directly related to the local projected mass of the specimen it became feasible to determine the molecular mass and mass distribution within individual macromolecules and from these data to calculate the linear density (M/L) and the radii of gyration.2 This parameter (RQ), reflecting the three-dimensional structure of the macromolecular particles in solution, has been applied to monitor the conformational transitions in E. coli 16S and 23S ribosomal RNAs in solutions of various ionic strength.In spite of the differences in mass (550 kD and 1050 kD, respectively), both 16S and 23S RNA appear equally sensitive to changes in buffer conditions. In deionized water or conditions of extremely low ionic strength both appear as filamentous structures (Fig. la and 2a, respectively) possessing a major backbone with protruding branches which are more frequent and more complex in 23S RNA (Fig. 2a).


Author(s):  
S. Trachtenberg ◽  
D. J. DeRosier

The bacterial cell is propelled through the liquid environment by means of one or more rotating flagella. The bacterial flagellum is composed of a basal body (rotary motor), hook (universal coupler), and filament (propellor). The filament is a rigid helical assembly of only one protein species — flagellin. The filament can adopt different morphologies and change, reversibly, its helical parameters (pitch and hand) as a function of mechanical stress and chemical changes (pH, ionic strength) in the environment.


Author(s):  
J P Cassella ◽  
V Salih ◽  
T R Graham

Left ventricular assist systems are being developed for eventual long term or permanent implantation as an alternative to heart transplantation in patients unsuitable for or denied the transplant option. Evaluation of the effects of these devices upon normal physiology is required. A preliminary study was conducted to evaluate the morphology of aortic tissue from calves implanted with a pneumatic Left Ventricular Assist device-LVAD. Two 3 month old heifer calves (calf 1 and calf 2) were electively explanted after 128 days and 47 days respectively. Descending thoracic aortic tissue from both animals was removed immediately post mortem and placed into karnovsky’s fixative. The tissue was subsequently processed for transmission electron microscopy (TEM). Some aortic tissue was fixed in neutral buffered formalin and processed for routine light microscopy.


2021 ◽  
Author(s):  
Hicham Zaroual ◽  
El Mestafa El Hadrami ◽  
Romdhane Karoui

This study examines the feasibility of using front face fluorescence spectroscopy (FFFS) to authenticate 41 virgin olive oil (VOO) samples collected from 5 regions in Morocco during 2 consecutive crop seasons.


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