Ultrasound assisted crystallization of cephalexin monohydrate: Nucleation mechanism and crystal habit control

2021 ◽  
Author(s):  
Zeren Shang ◽  
Mingchen Li ◽  
Baohong Hou ◽  
Junli Zhang ◽  
Kuo Wang ◽  
...  
Keyword(s):  
Nucleation Mechanism ◽  
Crystal Habit ◽  
Ultrasound Assisted

scholarly journals Investigation of an Unusual Crystal Habit of Hydrochlorothiazide Reveals Large Polar Enantiopure Domains and a Possible Crystal Nucleation Mechanism

2019 ◽  
Vol 58 (30) ◽  
pp. 10255-10259 ◽  
Author(s):  
Sajesh P. Thomas ◽  
Arnaud Grosjean ◽  
Gavin R. Flematti ◽  
Amir Karton ◽  
Alexandre N. Sobolev ◽  
...  
Keyword(s):  
Nucleation Mechanism ◽  
Crystal Nucleation ◽  
Crystal Habit

scholarly journals Investigation of an Unusual Crystal Habit of Hydrochlorothiazide Reveals Large Polar Enantiopure Domains and a Possible Crystal Nucleation Mechanism

2019 ◽  
Vol 131 (30) ◽  
pp. 10361-10365 ◽  
Author(s):  
Sajesh P. Thomas ◽  
Arnaud Grosjean ◽  
Gavin R. Flematti ◽  
Amir Karton ◽  
Alexandre N. Sobolev ◽  
...  
Keyword(s):  
Nucleation Mechanism ◽  
Crystal Nucleation ◽  
Crystal Habit

Transmission Electron Microscopy characterization of epitaxial III-V semiconductor thin films grown on Si(100) by ion-assisted deposition

1990 ◽  
Vol 48 (4) ◽  
pp. 686-687
Author(s):  
L. Hultman ◽  
C.-H. Choi ◽  
R. Kaspi ◽  
R. Ai ◽  
S.A. Barnett
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Ion Irradiation ◽  
High Energy ◽  
Nucleation Mechanism ◽  
Layer By Layer ◽  
Extended Defect ◽  
Island Formation ◽  
Si Substrates ◽  
Transmission Electron

III-V semiconductor films nucleate by the Stranski-Krastanov (SK) mechanism on Si substrates. Many of the extended defects present in the films are believed to result from the island formation and coalescence stage of SK growth. We have recently shown that low (-30 eV) energy, high flux (4 ions per deposited atom), Ar ion irradiation during nucleation of III-V semiconductors on Si substrates prolongs the 1ayer-by-layer stage of SK nucleation, leading to a decrease in extended defect densities. Furthermore, the epitaxial temperature was reduced by >100°C due to ion irradiation. The effect of ion bombardment on the nucleation mechanism was explained as being due to ion-induced dissociation of three-dimensional islands and ion-enhanced surface diffusion.For the case of InAs grown at 380°C on Si(100) (11% lattice mismatch), where island formation is expected after ≤ 1 monolayer (ML) during molecular beam epitaxy (MBE), in-situ reflection high-energy electron diffraction (RHEED) showed that 28 eV Ar ion irradiation prolonged the layer-by-layer stage of SK nucleation up to 10 ML. Otherion energies maintained layer-by-layer growth to lesser thicknesses. The ion-induced change in nucleation mechanism resulted in smoother surfaces and improved the crystalline perfection of thicker films as shown by transmission electron microscopy and X-ray rocking curve studies.

Innovative Extraction Techniques for the Optimum Extraction of Phenolic Compounds from Peanut Meal and Evaluation of Their Biological Activities

2019 ◽  
Vol 4 (2) ◽  
Keyword(s):  
Phenolic Compounds ◽  
Carcinoma Cell ◽  
Biological Activities ◽  
Peanut Meal ◽  
Ultrasound Assisted Extraction ◽  
Carcinoma Cell Lines ◽  
Assisted Extraction ◽  
Phenolic Extract ◽  
Ultrasound Assisted ◽  
Water Ratio

There is a worldwide demand for phenolic compounds (PC) because they exhibit several biological activities. This work aimed at extracting phenolic compounds from peanut meal. The methods of extraction were mainly: conventional solvent extraction (traditional methods) and ultrasound assisted extraction (recent methods) and comparing their results. Peanut meal (PM) was prepared by defatting with n-hexane, and then extracted by the two previous methods. First, the conventional solvents used were 80% methanol, ethanol, acetone, isopropanol, and distilled water. Then studied Different parameters such as meal: water ratio, also the effect of temperature and the pH on the extraction process. Second, ultrasonic assisted extractions (USAE), the parameters investigated were temperature, time and speed of sonication. Finally, all the extracts were analyzed by HPLC for their phenolic contents. Results indicated that the highest extracted PC achieved by solvents was in distilled water where 1:100, Meal: Water ratio which extracted 40 mg PC / g PM at 30& 35°C. Highest extracted PC was achieved by alkaline medium at pH 12 more than acidic and neutral medium. While (USAE) at speed 8 ultrasonication and temperature 30ᵒC, extracted 49.2mg PC /g PM. Sothe ultrasound assisted extraction exhibited great influence on the extraction of phenolic compounds from peanut meal. The ultrasonic peanut extract was examined for its antioxidant, antimicrobial and anticarcinogenic activities. The antioxidant activity of PM phenolic extract prepared by ultrasonic technique, was measured by, β-carotene, and DPPH methods, and reducing antioxidant power. Results revealed values: 84.57, 57.72 and 5960 respectively. The PM extract showed different levels of antimicrobial activity against the pathogenic bacteria used. As for the anticarcinogenic effect PM phenolic extract most effective on inhibiting colon carcinoma and lung carcinoma cell lines with IC50 = 20.7 and 20.8 µ/ml., respectively. This was followed by intestinal carcinoma and liver carcinoma cell lines with IC50= 39.6 and 40.2µ/ml.

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