scholarly journals Fabrication of Porous Bone Scaffolds Using Alginate and Bioactive Glass

2019 ◽  
Vol 10 (1) ◽  
pp. 15 ◽  
Author(s):  
Jonathan Hatton ◽  
Graham Roy Davis ◽  
Abdel-Hamid I. Mourad ◽  
Nizamudeen Cherupurakal ◽  
Robert G. Hill ◽  
...  
Keyword(s):  
Bioactive Glass ◽  
Pore Size ◽  
Composite Scaffold ◽  
Average Pore Size ◽  
Amorphous Structure ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Average Pore ◽  
X Ray ◽  
Novel Material

Porous composite scaffold using an alginate and bioactive glass ICIE16M was synthesized by a simple freeze-drying technique. The scaffold was characterized using compression testing, Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), X-ray diffraction (XRD), X-ray microtomography (XMT) and scanning electron microscopy (SEM). The bioactivity of the scaffold was evaluated by its ability to form apatite on its surface in simulated body fluid (SBF). The data collected showed evidence that the novel material produced had an appropriate pore size for osteoconduction, with an average pore size of 110 µm and maximum pore size of 309 µm. Statistical analysis confirmed that the glass filler significantly (P < 0.05) increased the collapse yield of the scaffolds compared with pure alginate scaffolds. The ICIE16M glass had an amorphous structure, favorable for bioactivity.

Obtaining Ceramic Filter from Rice Husk and Kaolinitic Clay

2014 ◽  
Vol 802 ◽  
pp. 232-238 ◽  
Author(s):  
R.P.A. Souza ◽  
F.V. Motta ◽  
R.G. Carvalho ◽  
W. Acchar ◽  
E. Harima ◽  
...  
Keyword(s):  
Pore Size ◽  
Rice Husk ◽  
Average Pore Size ◽  
Mercury Porosimetry ◽  
Standard Technique ◽  
Ceramic Filter ◽  
X Ray Diffraction ◽  
Average Pore ◽  
X Ray ◽  
Kaolinitic Clay

In this study, different compositions based on rice husk carbon and kaolinitic clay aimed at obtaining ceramic filter were studied. Three compositions of 40, 60 and 80% rice husk of the total mass were prepared. The specimens were uniaxially compressed in rectangular shape at pressure of 28 MPa and were sintered at temperatures of 1100oC, 1150oC and 1200oC for 1 h. The sintered samples were characterized according to standard technique for linear shrinkage, water absorption, apparent porosity and flexural strength. Scanning Electron Microscopy (SEM) was also performed to check the average pore size, and X-Ray Diffraction (XRD) to verify existing crystalline phases, chemical analysis and mercury porosimetry. The X-ray diffraction results showed mostly alpha quartz peaks and mullite after sintering. Mercury porosimetry showed porosity of 44.33% and average pore size of approximately 8.33 μm for sample with 60% rice husk sintered at 1200°C.

Polymer Embedded Nanocrystalline Titania Sorbent for 99Mo-99mTc Generator

2008 ◽  
Vol 8 (9) ◽  
pp. 4447-4452 ◽  
Author(s):  
Rubel Chakravarty ◽  
Rakesh Shukla ◽  
Shyamla Gandhi ◽  
Ramu Ram ◽  
Ashutosh Dash ◽  
...  
Keyword(s):  
Saline Solution ◽  
Average Pore Size ◽  
Average Crystallite Size ◽  
Activity Level ◽  
X Ray Diffraction ◽  
Average Pore ◽  
X Ray ◽  
Nano Crystalline ◽  
99Mtc Generator

A new sorbent material, polymer embedded nano crystalline titania (Titanium Polymer-TiP) has been developed, from titanium (IV) chloride and isopropyl alcohol, for the adsorption of 99Mo, which is a precursor to 99mTc, a workhorse in radio-pharmaceuticals. The infrared absorption spectra of the TiP showed peaks corresponding to Ti-O groups. X-ray diffraction pattern of the adsorbent corresponded to rutile TiO2. The surface area of this polymer was 30 m2/g with an average pore size of 40 nm. The average crystallite size of TiO2, embedded in polymer, was found to be 5 nm. TEM micrograph of the adsorbent revealed the networkof polymer with dispersed titania phase. Potential of this adsorbent for the preparation of 99Mo-99mTc generator has been explored. 99Mo could be adsorbed on to the adsorbent column containing TiP at pH 1 from which 99mTc could be eluted with normal (0.9%) saline solution with an elution yield of ∼80%. The quality of the 99mTcO−4 obtained was in accordance with the international specifications applicable for radiopharmaceutical use. A process demonstration run was carried out with 1.1 GBq (30 mCi) 99Mo activity level making use of the above adsorbent and consistent results were obtained over a period of one week, which is generally the shelf life of 99Mo-99mTc generator.

Structure Evolution of La(OH)3 /Fe Composite during Ball Milling

2020 ◽  
Vol 65 ◽  
pp. 123-134
Author(s):  
Samira Lalaoua ◽  
Bouguerra Bouzabata ◽  
Safia Alleg ◽  
Abedelmalik Djekoun ◽  
David Shmool
Keyword(s):  
Ball Milling ◽  
Milling Time ◽  
Magnetic Measurements ◽  
Amorphous Structure ◽  
Structure Evolution ◽  
Vibrating Sample Magnetometer ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Composite Powders ◽  
X Ray

Fe-10wt% La (OH)3 composite powders have been fabricated by ball milling, under argon atmosphere for milling periods of 0, 5 and 10 h, respectively. Changes in structural, morphological, thermal and magnetic properties of the powders during mechanical alloying and during subsequent annealing have been examined by X-ray diffraction, scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and vibrating sample magnetometer (VSM). XRD results: showed the formation of new phases (Fe and LaFeO3 perovskite) created through the ball milling. The results showed that the crystalline size of ball milled powders decreased with increasing the milling time. In fact, after 10 h of ball milling, La (OH)3 changes from nanostructure in amorphous structure. The magnetic measurements display a distinct saturation magnetization and coercivity.

scholarly journals CELL-FREE TRANSMISSION IN ADULT SWISS MICE OF A DISEASE HAVING THE CHARACTER OF A LEUKEMIA

1957 ◽  
Vol 105 (4) ◽  
pp. 307-318 ◽  
Author(s):  
Charlotte Friend
Keyword(s):  
Pore Size ◽  
Average Pore Size ◽  
Splenic Tissue ◽  
Cell Suspensions ◽  
Average Pore ◽  
X Ray ◽  
Membrane Filters ◽  
Swiss Mice ◽  
Intramuscular Injections

A disease with the characteristics of a leukemia has been found to be serially transmissible in adult Swiss mice by means of cell-free filtrates. Thus far, the disease has been transmitted through twenty-six serial passages with filtrates as well as cell suspensions. The agent readily passes through Selas 03, Berkefeld N, and gradocol membrane filters—these last having an average pore size of 220 mµ. Filtrates remain stable when stored for long periods at –70°C. or when lyophilized. Splenic tissue containing the agent, which was subjected to massive doses of x-ray (50,000 r),—far more than sufficient to kill the cells,—show undiminished infectivity. The agent is inactivated by heating to 56°C. for 30 minutes and by exposure to ether or formalin. The disease can be transmitted to adult Swiss mice or DBA/2 mice, but not to adult PRI, C3H, A, C57B1/6, or F1(C58 x BALB) mice. Intraperitoneal, subcutaneous, intracerebral, and intramuscular injections are all effective.

Electrochemical Fabrication of Porous Interconnected Copper Foam

2021 ◽  
Vol 902 ◽  
pp. 9-14
Author(s):  
Mary Donnabelle L. Balela ◽  
Reginald E. Masirag ◽  
Francis O. Pacariem Jr. ◽  
Juicel Marie D. Taguinod
Keyword(s):  
Wall Thickness ◽  
Current Density ◽  
Pore Diameter ◽  
Average Pore Size ◽  
X Ray Diffraction ◽  
Average Pore ◽  
X Ray ◽  
Copper Foam ◽  
Electrochemical Fabrication ◽  
Cu Foam

An interconnected copper network or copper foam was successfully fabricated by electrochemical deposition using polyethylene glycol (PEG) and sodium bromide (NaBr) as additives. Both the amount of PEG and the current density were varied to obtain a Cu foam with the smallest pore diameter and wall thickness. The increasing amount of PEG resulted in a decrease in pore diameter. However, the wall thickness of the Cu network was increased. At 800 mg/L PEG and 20 mM NaBr, the average pore size of the foam was about 11.03 µm. Dendritic formation was also observed on the walls of the Cu foam. Further, higher current density resulted in increased dendritic growth. X-ray diffraction confirms that the Cu foam was spontaneously oxidized in air, leading to the formation of cuprous oxide (Cu2O).

scholarly journals Crystallization Process and Microstructural Evolution of Melt Spun Al-RE-Ni-(Cu) Ribbons

Metals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 443
Author(s):  
Francisco G. Cuevas ◽  
Sergio Lozano-Perez ◽  
Rosa María Aranda ◽  
Raquel Astacio
Keyword(s):  
Crystallization Process ◽  
Primary Crystallization ◽  
Amorphous Structure ◽  
Intermetallic Phases ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Transmission Electron ◽  
Melt Spun ◽  
The Stability

The crystallization process, both at the initial and subsequent stages, of amorphous Al88-RE4-Ni8 alloys (RE = Y, Sm and Ce) has been studied. Additionally, the consequences of adding 1 at.% Cu replacing Ni or Al were studied. The stability of the amorphous structure in melt spun ribbons was thermally studied by differential scanning calorimetry, with Ce alloys being the most stable. The effect of Cu to reduce the nanocrystal size during primary crystallization was analyzed by transmission electron microscopy. This latter technique and x-ray diffraction showed the formation of intermetallic phases at higher temperatures. A clear difference was observed for the Ce alloy, with a simpler sequence involving the presence of Al3Ni and Al11Ce3. However, for the Y and Sm alloys, a more complex evolution involving metastable ternary phases before Al19RE5Ni3 appears, takes place. The shape of the intermetallics changes from equiaxial in the Ce alloys to elongate for Y and Sm, with longer particles for Sm and, in general, when Cu is added to the alloy.

Characterization of Glass Forming Alloy Fe43.2Co28.8B19.2Si4.8Nb4 Processed by Spray Forming and Wedge Mold Casting Techniques

2011 ◽  
Vol 691 ◽  
pp. 23-26 ◽  
Author(s):  
C. Triveño Rios ◽  
Conrado R. M. Afonso ◽  
Claudemiro Bolfarini ◽  
Walter José Botta Filho ◽  
Claudio Shyinti Kiminami
Keyword(s):  
Amorphous Structure ◽  
Spray Forming ◽  
Bulk Glass ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Glass Forming ◽  
Glassy Alloys ◽  
Mold Casting

Bulk glassy alloys based on the Fe-Co-B-Si-Nb system have already achieved high levels of mechanical strength. The present work investigated the microstructural evolution of Fe43.2Co28.8B19.2Si4.8Nb4 alloy during the spray forming and wedge mold casting processes, with emphasis on the formation of amorphous phase. The microstructure was evaluated by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and X-ray diffraction (XRD). The region outer the spray deposit showed the formation of an amorphous structure with a thickness of ~2.5 mm, while that of the wedge-shaped sample exhibited a thickness of up to ~1.5 mm, suggesting that both processes show a promising potential for the production of bulk glass alloys.

Effect of Crystallization on the Electrical Resistance and Structure of Amorphous Fe-Co-Cr-B-Si Alloys / Wpływ Krystalizacji Na Oporność Elektryczną I Strukturę Amorficznych Stopów Fe-Co-Cr-B-Si

2012 ◽  
Vol 57 (4) ◽  
pp. 1031-1039
Author(s):  
H. Solomon ◽  
N. Solomon
Keyword(s):  
Electrical Resistivity ◽  
Electrical Properties ◽  
Amorphous Alloys ◽  
Melt Spinning ◽  
Amorphous Structure ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Investigation Methods ◽  
Melt Spinning Technique

The goal of this paper is to present the influence of temperature variation and iron substitution with Co on the structure and electrical properties of amorphous Fe75-xCoxCr1B7Si17 alloys (where x=1, 4, 7, and 10 at.%), obtained by melt-spinning technique. The electrical resistivity of the samples was measured by using a usual four-probe method from -160°C to 750°C. The electrical resistivity was also measured at room temperature for the amorphous Fe75-xCoxCr1B7Si17 ribbons annealed at various temperatures for different holding time. The annealed samples were also investigated by Vickers microhardness test. The amorphous structure of tested materials was examined by X-ray diffraction (XRD), Mossbauer spectroscopy, differential scanning calorimetry (DSC) and scanning electron microscopy (SEM) methods. Experimental results confirmed the utility of applied investigation methods and the influence of the Co content and annealing process on the crystallization, structure and electrical properties of examined amorphous alloys.

Study on Amorphization of Mechanical Alloyed Cu50Zr40Ag10 Alloy

2011 ◽  
Vol 306-307 ◽  
pp. 1379-1382
Author(s):  
Lin Yan Xia ◽  
Yan Wang
Keyword(s):  
Mechanical Alloying ◽  
Amorphous Phase ◽  
Milling Time ◽  
Nearest Neighbor ◽  
Mechanical Stability ◽  
Amorphous Structure ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Short Range Ordering

The amorphization and crystallization of mechanical alloyed Cu50Zr40Ag10 alloy have been investigated using X-ray diffraction (XRD) and differential scanning calorimetry (DSC). The results demonstrate that a full amorphous phase of Cu50Zr40Ag10 can be obtained through mechanical alloying. The amorphous phase begins to show the initial mechanical crystallization when the milling time is 108 h and subsequently the main milling product is still amorphous structure with increasing milling time up to 208 h. Therefore, the amorphous alloy exhibits the excellent mechanical stability during mechanical alloying. The nearest-neighbor distance of atoms firstly increases then reduces with the increasing milling time, indicating that there is a closely correlation between the initial crystallization behavior and short range ordering.

Scaffolds of Collagen from Nukbone ®

2012 ◽  
Vol 1487 ◽  
Author(s):  
Benjamín H. León ◽  
Miguel A. Araiza ◽  
M. Cristina Piña
Keyword(s):  
Pore Size ◽  
Physical Adsorption ◽  
Thermo Gravimetric Analysis ◽  
Nitrogen Adsorption ◽  
Biological Tissues ◽  
Bovine Bone ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray

ABSTRACTThe scaffold is obtained from acellular bovine bone: Nukbone® (produced by Biocriss SAPI de CV). This acellular bone was subjected to a demineralization process after which the composition was found to be 10% water, 65% of collagen and 25% of hydroxyapatite. The techniques used to characterize these natural scaffolds were: optical microscopy, scanning electron microscopy, X-ray diffraction, energy dispersive X-ray spectroscopy, thermo gravimetric analysis, differential scanning calorimetry and determination of pore size using nitrogen adsorption, and physical adsorption of N2. The pore size is between 100 and 500 microns. These scaffolds have been tested in several biological tissues as urethra, trachea, blood vessels, bone and heart successfully.

Sign in / Sign up

Export Citation Format

Share Document