Fabrication of Bioactive Apatite Nuclei-Precipitated Titanium Alloys by Using Sandblasting

2012 ◽  
Vol 529-530 ◽  
pp. 553-558 ◽  
Author(s):  
Hiroshi Mizuno ◽  
Takeshi Yabutsuka ◽  
Takeshi Yao

Micropores were formed on the surface of Ti metal, Ti-15Mo-5Zr-3Al alloy, Ti-12Ta-9Nb-3V-6Zr-O alloy plate by doubled sandblasting process using silicon carbide particles with 14.0 μm for average particle size as first process, then using the particles with 3.0 μm for average particle size as second process. Apatite Nuclei (AN) were precipitated in the pores. By these treatments, bioactive AN-precipitated Ti alloys were fabricated. Bioactivity of the AN-precipitated Ti alloys was examined by soaking in SBF and it was observed that hydroxyapatite was induced on the surface of the Ti alloys within 1 d. High adhesive strength of hydroxyapatite layer was achieved due to a mechanical interlocking effect between hydroxyapatite formed in the micropores and the plate.

2014 ◽  
Vol 631 ◽  
pp. 231-235 ◽  
Author(s):  
Takeshi Yabutsuka ◽  
Hiroshi Mizuno ◽  
Ryoki Karashima ◽  
Takeshi Yao

Micropores were formed on the surface of Ti-15Mo-5Zr-3Al alloy plate by doubled sandblasting process using silicon carbide particles with 14.0 μm and/or 3.0 µm average particle size by changing the combination of the size of particles. Apatite Nucleus (AN) was precipitated in the pores. By these treatments, bioactive AN precipitated Ti alloys were fabricated. Bioactivity of the Ti alloys was examined by soaking in SBF. Formed hydroxyapatite showed highest adhesive strength in the case of sandblasting using 14.0 μm particles then using 3.0 μm particles.


2013 ◽  
Vol 587 ◽  
pp. 165-170 ◽  
Author(s):  
Takeshi Yabutsuka ◽  
Hiroshi Mizuno ◽  
Takeshi Yao

Micropores were formed on the surface of polylactic acid (PLA) plate by doubled sandblasting process using alumina particles with 14.0 μm for average particle size as first process, then using the particles with 3.0 μm for average particle size as second process. Apatite Nucleus (AN) was precipitated in the pores. By these treatments, bioactive AN precipitated PLA was fabricated. Bioactivity of the AN precipitated PLA was examined by soaking in SBF and it was observed that hydroxyapatite was induced on the surface of the PLA within 1 d. High adhesive strength of hydroxyapatite layer was achieved due to a mechanical interlocking effect between hydroxyapatite formed in the micropores and the PLA plate.


1996 ◽  
Vol 11 (7) ◽  
pp. 1601-1604 ◽  
Author(s):  
Mamoru Mitomo ◽  
Young-Wook Kim ◽  
Hideki Hirotsuru

Ultrafine silicon carbide powder with an average particle size of 90 nm was densified by hot-processing with the addition of Al2O3, Y2O3, and CaO at 1750 °C. Silicon carbide nanoceramics with an average grain size of 110 nm were prepared by liquid phase sintering at low temperature. The materials showed superplastic deformation at a strain rate of 5.0 × 10-4/s at 1700 °C, which is the lowest temperature published. The microstructure and deformation behavior of materials from a submicrometer powder were also investigated as a reference.


2019 ◽  
Vol 944 ◽  
pp. 705-713
Author(s):  
Xiao Hong Wang ◽  
Qiao Gang Hu ◽  
Shi Yu Zhong ◽  
Teng Dang ◽  
Hai Lun Wang ◽  
...  

The wettability between silicon carbide and aluminum is poor, silicon carbide is difficult to fuse or the distribution of silicon carbide is not uniform in the ingot when the SiCp / 7075 composite is prepared by melt casting.The surface modification of SiCp by nickel plating can significantly reduce the wetting angle of SiC/Al and improve the distribution uniformity of silicon carbide in SiCp / 7075. In this thesis, the thermal compression process 6.5% SiCp / 7075 reinforced by nickel-plated modified silicon carbide is simulated by DEFOEM-3D software.The influence of the shape and particle size of nickel-plated modified silicon carbide on its compressive damage has been highlighted, and the deformation characteristics of the SiC/Ni/Al interface layer in the thermal compression process have been discussed. The numerical simulation results show that the 6.5% SiCp / 7075 reinforced by spherical nickel-plated modified silicon carbide particles with a particle size of 15 μm has the smallest compression damage value of 0.0426, at this point the compression temperature is 400°C, the compression ratio is 15, and the compression rate is 0.03s-1. the hot compression test of 6.5% SiCp / 7075 reinforced by spherical nickel-plated modified silicon carbide particles with a particle size of 15 μm was performed by using the same compression parameters as the numerical simulation. After hot pressing, the sample had a smooth surface with few obvious cracks, which was consistent with the numerical simulation results. Key words: nickel-plating modification; silicon carbide particles; compressive damage; grain size; grain morphology


1970 ◽  
Vol 26 (1) ◽  
pp. 16 ◽  
Author(s):  
S Balasubramanian ◽  
Rajkumar Rajkumar ◽  
K K Singh

Experiment to identify ambient grinding conditions and energy consumed was conducted for fenugreek. Fenugreek seeds at three moisture content (5.1%, 11.5% and 17.3%, d.b.) were ground using a micro pulverizer hammer mill with different grinding screen openings (0.5, 1.0 and 1.5 mm) and feed rate (8, 16 and 24 kg h-1) at 3000 rpm. Physical properties of fenugreek seeds were also determined. Specific energy consumptions were found to decrease from 204.67 to 23.09 kJ kg-1 for increasing levels of feed rate and grinder screen openings. On the other hand specific energy consumption increased with increasing moisture content. The highest specific energy consumption was recorded for 17.3% moisture content and 8 kg h-1 feed rate with 0.5 mm screen opening. Average particle size decreased from 1.06 to 0.39 mm with increase of moisture content and grinder screen opening. It has been observed that the average particle size was minimum at 0.5 mm screen opening and 8 kg h-1 feed rate at lower moisture content. Bond’s work index and Kick’s constant were found to increase from 8.97 to 950.92 kWh kg-1 and 0.932 to 78.851 kWh kg-1 with the increase of moisture content, feed rate and grinder screen opening, respectively. Size reduction ratio and grinding effectiveness of fenugreek seed were found to decrease from 4.11 to 1.61 and 0.0118 to 0.0018 with the increase of moisture content, feed rate and grinder screen opening, respectively. The loose and compact bulk densities varied from 219.2 to 719.4 kg m-3 and 137.3 to 736.2 kg m-3, respectively.  


2020 ◽  
Vol 27 (22) ◽  
pp. 3623-3656 ◽  
Author(s):  
Bruno Fonseca-Santos ◽  
Patrícia Bento Silva ◽  
Roberta Balansin Rigon ◽  
Mariana Rillo Sato ◽  
Marlus Chorilli

Colloidal carriers diverge depending on their composition, ability to incorporate drugs and applicability, but the common feature is the small average particle size. Among the carriers with the potential nanostructured drug delivery application there are SLN and NLC. These nanostructured systems consist of complex lipids and highly purified mixtures of glycerides having varying particle size. Also, these systems have shown physical stability, protection capacity of unstable drugs, release control ability, excellent tolerability, possibility of vectorization, and no reported production problems related to large-scale. Several production procedures can be applied to achieve high association efficiency between the bioactive and the carrier, depending on the physicochemical properties of both, as well as on the production procedure applied. The whole set of unique advantages such as enhanced drug loading capacity, prevention of drug expulsion, leads to more flexibility for modulation of drug release and makes Lipid-based nanocarriers (LNCs) versatile delivery system for various routes of administration. The route of administration has a significant impact on the therapeutic outcome of a drug. Thus, the non-invasive routes, which were of minor importance as parts of drug delivery in the past, have assumed added importance drugs, proteins, peptides and biopharmaceuticals drug delivery and these include nasal, buccal, vaginal and transdermal routes. The objective of this paper is to present the state of the art concerning the application of the lipid nanocarriers designated for non-invasive routes of administration. In this manner, this review presents an innovative technological platform to develop nanostructured delivery systems with great versatility of application in non-invasive routes of administration and targeting drug release.


2020 ◽  
Vol 17 ◽  
Author(s):  
Mohammad Hossain Shariare ◽  
Tonmoy Kumar Mondal ◽  
Hani Alothaid ◽  
Md. Didaruzzaman Sohel ◽  
MD Wadud ◽  
...  

Aim: EPAS (evaporative precipitation into aqueous solution) was used in the current studies to prepare azithromycin nanosuspensions and investigate the physicochemical characteristics for the nanosuspension batches with the aim of enhancing the dissolution rate of the nanopreparation to improve bioavailability. Methods: EPAS method used in this study for preparing azithromycin nanosuspension was achieved through developing an in-house instrumentation method. Particle size distribution was measured using Zetasizer Nano S without sample dilution. Dissolved azithromycin nanosuspensions were also compared with raw azithromycin powder and commercially available products. Total drug content of nanosuspension batches were measured using an Ultra-Performance Liquid Chromatography (UPLC) system with Photodiode Array (PDA) detector while residual solvent was measured using gas chromatography (GC). Results: The average particle size of azithromycin nanosuspension was 447.2 nm and total drug content was measured to be 97.81% upon recovery. Dissolution study data showed significant increase in dissolution rate for nanosuspension batch when compared to raw azithromycin and commercial version (microsuspension). The residual solvent found for azithromycin nanosuspension is 0.000098023 mg/ mL or 98.023 ppb. Conclusion: EPAS was successfully used to prepare azithromycin nanoparticles that exhibited significantly enhanced dissolution rate. Further studies are required to scale up the process and determine long term stability of the nanoparticles.


Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2003
Author(s):  
Wei Xu ◽  
Jintao Wei ◽  
Zhengxiong Chen ◽  
Feng Wang ◽  
Jian Zhao

The type and fineness of a filler significantly affect the performance of an asphalt mixture. There is a lack of specific research on the effects of filler fineness and dust from aggregates on the properties of epoxy asphalt (EA) mixtures. The effects of aggregate dust and mineral powder on the properties of an EA mixture were evaluated. These filler were tested to determine their fineness, specific surface area and mineral composition. The effects of these fillers on the EA mastic sample and mixture were evaluated. The morphology of the EA mastic samples was analyzed using scanning electron microscopy (SEM). The effects of the fillers on the Marshall stability, tensile strength and fatigue performance of the EA mixture were evaluated. The dust from the aggregates exhibited an even particle size distribution, and its average particle size was approximately 20% of that of the mineral powder. The SEM microanalysis showed that the EA mastic sample containing relatively fine dust formed a tight and dense interfacial bonding structure with the aggregate. The EA mixture sample containing filler composed of dust from aggregate had a significantly higher strength and longer fatigue life than that of the EA sample containing filler composed of mineral powder.


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