Characterization of Type B Carbonate Apatite Sintered Bodies

2011 ◽  
Vol 1301 ◽  
Author(s):  
N. Watanobe ◽  
T. Yoshioka ◽  
T. Ikoma ◽  
T. Kuwayama ◽  
T. Higaki ◽  
...  
Keyword(s):  
Dissolution Kinetics ◽  
Carbonate Apatite ◽  
Artificial Bone ◽  
Type B ◽  
Desorption Process ◽  
Different Temperatures ◽  
Acidic Conditions ◽  
Kinetics Of ◽  
Potential Use

ABSTRACTThe dissolution kinetics of type B carbonate apatite (CAp) disks sintered at different temperatures were investigated under acidic conditions similar to an osteoclastic desorption process in bone remodeling. The type B CAp disks, which were uniaxially pressed at 98MPa and sintered at temperatures of 600 to 700 ºC, showed single crystalline phase and a high relative density of 60-62 % compared to the stoichiometric density of 3.16g/cm3 of hydroxyapatite (HAp). The dissolution rate of type B CAp disks sintered at 650 ºC was 3.5 times faster than that of HAp disks at 650 ºC. These results indicate that the Type B CAp sintered disks show potential use as a biodegradable material for artificial bone.

Dissolution kinetics of IMX-101 and IMX 104 : Operating Procedure series : characterization of IMX dissolution

2016 ◽  
Author(s):  
Christian McGrath ◽  
Beth Porter ◽  
Jonathon Brame ◽  
Mark Chappell ◽  
Amber Russell
Keyword(s):  
Operating Procedure ◽  
Dissolution Kinetics ◽  
Kinetics Of

scholarly journals Application of the Shrinking-Core Models for Determination of Dissolution Kinetics of Mn and Zn from Spent Zinc–Carbon Battery Powder in Organic Acid Solution

2019 ◽  
Vol 27 (1) ◽  
pp. 99-109 ◽  
Author(s):  
Tevfik Agacayak ◽  
Hasan Ali Taner
Keyword(s):  
Acetic Acid ◽  
Acid Solution ◽  
Acetic Acid Solution ◽  
Dissolution Kinetics ◽  
Kinetic Studies ◽  
Product Layer ◽  
Different Temperatures ◽  
Shrinking Core ◽  
Kinetics Of Dissolution ◽  
Kinetics Of

Abstract In this study, dissolution kinetics of manganese and zinc from spent zinc–carbon batteries in acetic acid solution was investigated. To determine the kinetics of dissolution of manganese and zinc, shrinking core model was applied to dissolution recoveries obtained at different temperatures. As a result of kinetic studies, it was determined that manganese and zinc were dissolved in acetic acid solution by diffusion from product layer and then activation energies (Ea) were calculated.

scholarly journals Oligomerization Profile of Human Transthyretin Variants with Distinct Amyloidogenicity

Molecules ◽  
2020 ◽  
Vol 25 (23) ◽  
pp. 5698
Author(s):  
Ana Frangolho ◽  
Bruno E. Correia ◽  
Daniela C. Vaz ◽  
Zaida L. Almeida ◽  
Rui M. M. Brito
Keyword(s):  
Early Stage ◽  
Clinical Manifestations ◽  
Attr Amyloidosis ◽  
Amyloid Fibril Formation ◽  
Acidic Conditions ◽  
Novel Therapeutic Strategies ◽  
Amyloid Diseases ◽  
Kinetics Of ◽  
Identification And Characterization

One of the molecular hallmarks of amyloidoses is ordered protein aggregation involving the initial formation of soluble protein oligomers that eventually grow into insoluble fibrils. The identification and characterization of molecular species critical for amyloid fibril formation and disease development have been the focus of intense analysis in the literature. Here, using photo-induced cross-linking of unmodified proteins (PICUP), we studied the early stages of oligomerization of human transthyretin (TTR), a plasma protein involved in amyloid diseases (ATTR amyloidosis) with multiple clinical manifestations. Upon comparison, the oligomerization processes of wild-type TTR (TTRwt) and several TTR variants (TTRV30M, TTRL55P, and TTRT119M) clearly show distinct oligomerization kinetics for the amyloidogenic variants but a similar oligomerization mechanism. The oligomerization kinetics of the TTR amyloidogenic variants under analysis showed a good correlation with their amyloidogenic potential, with the most amyloidogenic variants aggregating faster (TTRL55P > TTRV30M > TTRwt). Moreover, the early stage oligomerization mechanism for these variants involves stepwise addition of monomeric units to the growing oligomer. A completely different behavior was observed for the nonamyloidogenic TTRT119M variant, which does not form oligomers in the same acidic conditions and even for longer incubation times. Thorough characterization of the initial steps of TTR oligomerization is critical for better understanding the origin of ATTR cytotoxicity and developing novel therapeutic strategies for the treatment of ATTR amyloidosis.

scholarly journals Characterization of Native and Graft Copolymerized Albizia Gums and Their Application as a Flocculant

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
T. Adeniyi Afolabi ◽  
Daniel G. Adekanmi
Keyword(s):  
Graft Copolymerization ◽  
Cold Water ◽  
Dissolution Kinetics ◽  
Steady Increase ◽  
Flocculation Efficiency ◽  
Emulsion Capacity ◽  
Albizia Saman ◽  
Kinetics Of ◽  
Oil Binding

The functional properties and flocculation efficiency of purified Albizia saman (AS) and Albizia glaberrima (AG) gum exudates modified by graft copolymerization with acrylamide were investigated. The grafting efficiency of AS and AG was 54 and 58%, respectively. The cold water-insoluble gel of native AS and AG was 38.23 and 35.55%, which increased to 39.75 and 40.55% after graft copolymerization. Graft copolymerization of AS and AG gums reduced their oil binding and emulsion capacity from 4.89 and 3.44% to 3.69 and 2.40%, respectively. The dissolution kinetics of the native gums between 40 and 90°C and 0 and 150 min revealed a steady increase in solubility of the native gums from 6.05 to 9.53 g/L (AS) and 5.90 to 8.78 g/L (AG). The flocculation efficiency of the native AS and AG gums at 50 ppm concentration was 74.30 and 74.73%, which increased to 98.46% and 98.29% in the graft copolymerized gums, respectively.

Preparation of modified sorbents from rehydrated clay materials

Clay Minerals ◽  
2012 ◽  
Vol 47 (2) ◽  
pp. 251-258
Author(s):  
M. Lhotka ◽  
V. Machovič ◽  
B. Doušová
Keyword(s):  
Chemical Properties ◽  
Solution Ph ◽  
Adsorption Capacities ◽  
Modification Method ◽  
Different Temperatures ◽  
Kinetics Of ◽  
Modified Sorbents ◽  
Highly Porous ◽  
Clay Materials

AbstractThe use of clay materials as selective sorbents for different contaminants requires very efficient methods. A natural kaolinite was calcined to metakaolinite and than rehydrated at different temperatures to produce a highly porous sorbent. The kinetics of this process were measured, with subsequent IR characterization of the phases formed. The surface and pore distribution of new phases were also assigned. In addition, the kaolinite obtained was pre-treated with Fe3+ ions to improve its sorption affinity for anionic particles. The rehydrated kaolinite and its Fe-modification were used for the adsorption of toxic cations (Zn, Cd, Pb) and anions (As, Se). Adsorption capacities depending on the physical chemical properties of the initial solution (pH, concentration of toxic ions) and the surface properties of the sorbent (specific surface area, modification method) were investigated. The adsorption properties of the sorbents were defined by the Langmuir model.

scholarly journals Dissolution kinetics of synthetic and natural meta-autunite minerals,X3−n(n)+[(UO2)(PO4)]2· xH2O, under acidic conditions

2007 ◽  
Vol 8 (11) ◽  
pp. n/a-n/a ◽  
Author(s):  
D. M. Wellman ◽  
K. M. Gunderson ◽  
J. P. Icenhower ◽  
S. W. Forrester
Keyword(s):  
Dissolution Kinetics ◽  
Acidic Conditions ◽  
Kinetics Of

scholarly journals Kinetics of dissolution of calcium phosphate (Ca-P) bioceramics

2008 ◽  
Vol 2 (1) ◽  
pp. 57-62 ◽  
Author(s):  
Lukas Brazda ◽  
Dana Rohanova ◽  
Ales Helebrant
Keyword(s):  
Calcium Phosphate ◽  
Dissolution Rate ◽  
Dissolution Kinetics ◽  
Weight Changes ◽  
Enhanced Dissolution ◽  
Different Temperatures ◽  
Sbf Solution ◽  
Kinetics Of Dissolution ◽  
Unexpected Findings ◽  
Kinetics Of

Hydroxyapatite (HAp) and ?-tricalcium phosphate (?-TCP) are widely used bioceramics for surgical or dental applications. This paper is dealing with dissolution kinetics of synthetically prepared ?-TCP and four types of HAp granules. Two groups of HAp, treated at different temperatures, each of them with two different granule sizes, were tested. Three corrosive solutions with different pH and simulated body fluid (SBF) were used for immersing of the samples. Changes in concentrations of calcium and phosphate ions, pH level and weight changes of the samples were observed. It was found that presence of TRIS buffer enhanced dissolution rate of the ?-TCP approximately two times. When exposed to SBF solution, calcium phosphate (most probably hydroxyapatite) precipitation predominates over ?-TCP dissolution. Results from HAp samples dissolution showed some unexpected findings. Neither heat treatment nor HAp particle size made any major differences in dissolution rate of the same mass of each HAp sample.

scholarly journals Processing and properties of pure antiferromagnetic h-YMnO3

2019 ◽  
Vol 13 (4) ◽  
pp. 427-434
Author(s):  
Milica Pocuca-Nesic ◽  
Zorica Marinkovic-Stanojevic ◽  
Patricia Cotic-Smole ◽  
Aleksandra Dapcevic ◽  
Nikola Tasic ◽  
...  
Keyword(s):  
Xrd Analysis ◽  
Complex Method ◽  
Ceramic Samples ◽  
Powder Samples ◽  
Different Temperatures ◽  
Citrate Precursors ◽  
Precursor Powders ◽  
Chemical Synthesis Route ◽  
Potential Use

Yttrium manganite (YMnO3) is widely investigated multiferroic material with potential use in many technological applications. In this paper, we report on the preparation and characterization of multiferroic hexagonal YMnO3 ceramics obtained by chemical synthesis route. Precursor powders were prepared by the polymerizable complex method from citrate precursors. After calcination at 900?C the powders contained mixture of Y-Mn-O phases which were further sintered at different temperatures. XRD analysis revealed that sintering at 1400?C resulted in the formation of pure hexagonal YMnO3. Density of the obtained ceramics was 96%TD. The ceramic samples proved to have multiferroic properties - they are antiferromagnetic below 42K with linear dependence of magnetization as a function of applied magnetic field. The ferroelectric measurements performed at room temperature showed remanent polarization of 0.21 ?C/cm2 and the coercive field of 6.0 kV/cm for the YMnO3 sample sintered at 1400?C. The magnetization curves measured at 2 and 5 K for the powder samples calcined at 900?C and ceramic samples sintered at 1300?C exhibited a hysteresis loop due to a small concentration of Mn3O4 in the samples.

An XPS study of the dissolution kinetics of chrysotile in 0.1 N oxalic acid at different temperatures

1977 ◽  
Vol 1 (4) ◽  
pp. 385-398 ◽  
Author(s):  
J. H. Thomassin ◽  
J. Goni ◽  
P. Baillif ◽  
J. C. Touray ◽  
M. C. Jaurand
Keyword(s):  
Oxalic Acid ◽  
Dissolution Kinetics ◽  
Different Temperatures ◽  
Xps Study ◽  
Kinetics Of
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