An investigation of spark discharge parameters for material processing with high power ultrasound

2007 ◽  
Vol 20 (12) ◽  
pp. 1159-1169 ◽  
Author(s):  
M.P. Wilson ◽  
L. Balmer ◽  
M.J. Given ◽  
S.J. MacGregor ◽  
I.V. Timoshkin
Keyword(s):  
Material Processing ◽  
High Power ◽  
Spark Discharge ◽  
Power Ultrasound ◽  
High Power Ultrasound ◽  
Discharge Parameters

scholarly journals Synthesis and Characterization of Nano-Sized 4-Aminosalicylic Acid–Sulfamethazine Cocrystals

Pharmaceutics ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 277 ◽  
Author(s):  
Ala’ Salem ◽  
Anna Takácsi-Nagy ◽  
Sándor Nagy ◽  
Alexandra Hagymási ◽  
Fruzsina Gősi ◽  
...  
Keyword(s):  
High Power ◽  
Active Pharmaceutical Ingredient ◽  
Polymorphic Form ◽  
Degree Of Crystallinity ◽  
Dissolution Enhancement ◽  
Aminosalicylic Acid ◽  
Nano Technology ◽  
Power Ultrasound ◽  
High Power Ultrasound ◽  
High Degree

Drug–drug cocrystals are formulated to produce combined medication, not just to modulate active pharmaceutical ingredient (API) properties. Nano-crystals adjust the pharmacokinetic properties and enhance the dissolution of APIs. Nano-cocrystals seem to enhance API properties by combining the benefits of both technologies. Despite the promising opportunities of nano-sized cocrystals, the research at the interface of nano-technology and cocrystals has, however, been described to be in its infancy. In this study, high-pressure homogenization (HPH) and high-power ultrasound were used to prepare nano-sized cocrystals of 4-aminosalysilic acid and sulfamethazine in order to establish differences between the two methods in terms of cocrystal size, morphology, polymorphic form, and dissolution rate enhancement. It was found that both methods resulted in the formation of form I cocrystals with a high degree of crystallinity. HPH yielded nano-sized cocrystals, while those prepared by high-power ultrasound were in the micro-size range. Furthermore, HPH produced smaller-size cocrystals with a narrow size distribution when a higher pressure was used. Cocrystals appeared to be needle-like when prepared by HPH compared to those prepared by high-power ultrasound, which had a different morphology. The highest dissolution enhancement was observed in cocrystals prepared by HPH; however, both micro- and nano-sized cocrystals enhanced the dissolution of sulfamethazine.

Particle Size Distribution of ZrO2:Pr3+ – Influences of pH, High Power Ultrasound, Surfactant and Dopant Quantity

2007 ◽  
Vol 128 ◽  
pp. 97-100 ◽  
Author(s):  
Stephanie Möller ◽  
Janusz D. Fidelus ◽  
Witold Łojkowski
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
High Power ◽  
Average Particle Size ◽  
Sodium Dodecyl ◽  
Average Particle ◽  
Power Ultrasound ◽  
High Power Ultrasound ◽  
Influence Of Ph

The aim of the work was to examine the influence of pH, high power ultrasound, surfactant and dopant quantity on the particle size distribution of ZrO2:Pr3+, with praseodymium content varying between 0.05 and 10 %. The nanopowders were obtained via a hydrothermal microwave driven process. To establish if the dopant was located on the surface of the zirconia nanoparticles, the particle size distribution, as a function of pH, was measured to obtain an estimate of the isoelectric point of the samples. All results indicated that the dopant was concentrated on the surface: the measurements of the particle size distribution show that the pH corresponding to maximum average particle size changes towards higher values when the Pr content increases. Measurements of the particle size distribution dependency on the application of high power ultrasound and the addition of the sodium dodecyl sulphate surfactant show that, under certain conditions, there is a better stabilisation of the nanopowders in a dispersion and undesirable agglomeration is hindered.

scholarly journals Production of large graphene sheets by exfoliation of graphite under high power ultrasound in the presence of tiopronin

2012 ◽  
Vol 48 (100) ◽  
pp. 12159 ◽  
Author(s):  
Mildred Quintana ◽  
Marek Grzelczak ◽  
Konstantinos Spyrou ◽  
Bart Kooi ◽  
Sara Bals ◽  
...  
Keyword(s):  
High Power ◽  
Graphene Sheets ◽  
Power Ultrasound ◽  
High Power Ultrasound
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