ultrasonic irradiation
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Author(s):  
Rosalina Rosalina ◽  
Ferry Ikhsandy ◽  
Agung Kurnia Yahya ◽  
Hibrah Hibrah

Nagari Sikucua, Kampung Dalam Subdistrict, Padang Pariaman produces nearly 800 tons of fragrant areca nut every year which is sent to Jambi to meet export needs. Areca nut contains tannins, substances that have many benefits, some of which are anti-inflammatory, corrosion inhibitors, antioxidants. This study aims to obtain tannins in areca nut extract through a kinetic maceration process with pre-treatment with ultrasonic irradiation wave. The dried areca nut was ground and sieved with various sizes of 20, 40 and 70 mesh and then extracted with ethanol as solvent. The concentration of ethanol used consisted of 35%, 50%, 65% and 80%. Ultrasonic irradiation waves were given for the initial 15 minutes of maceration and then continued with kinetic maceration for up to 4 hours in a water bath at 45°C. The extraction results were concentrated in a rotary evaporator and then tested for tannin levels using Follin Denish reagent in the standard series of tannic acid as a comparison with spectrophotometer UV-Vis. The highest yield of tannin content 11.10% was obtained in the 4-hour maceration process with pre-treatment ultrasonic irradiation at concentration of 80% ethanol with a size of 40 mesh.


2021 ◽  
Vol 11 (2) ◽  
Author(s):  
Aleksandra Minić Jančić ◽  
Danijela Ilić Komatina ◽  
Anka Todosijević ◽  
Dragana Stevanović

In this work we will report the formulation of novel 3-(pyridinylamino)-1-ferrocenylpropan-1-ones. A fruitful aza-Michael addition of pyridinamine moiety to a conjugated enone, 1-ferrocenylpropenone, has been accomplished by an ultrasonic irradiation of the mixture of these reactants. As the catalyst montmorillonite K-10 has been used and the reaction has been carried out as solvent-free, yielding ferrocene containing Mannich bases, compounds considered as important precursors in organic synthesis. The reaction score has been evaluated on three examples. The prepared products have been purified by column chromatography. In addition, a detailed characterization of the obtained 3-(pyridin-2-ylamino)-1-ferrocenylpropan-1-on and 3-(pyridin-3-ylamino)-1-ferrocenylpropan-1-on has been completed by IR and NMR spectroscopy, as well as elemental analyses.


Author(s):  
Hideto Onishi ◽  
Miyake Mikio ◽  
Hajime SHIRAI

Abstract Alkaline treatment of the photoresist under ultrasonic irradiation has been investigated to improve the resolution capability of resist patterns with higher throughput. The selectively dissolved phenol resin for the combination of the alkaline treatment with ultrasonic irradiation was increased by 2.3 times compared to the solely alkaline treatment. The sensitizing effect of naphthoquinone diazide (sensitizer) based on phenol was increased to 0.46 against dip treatment of 0.31. As a result, resist sensitivity was increased to 26% and the resolution capability was drastically improved. Consequently, the 0.5 μm line and space resist patterns were resolved completely with fine profile by using the photoresist with a 0.7 μm resolution limit together with g-line exposure machine with a 0.6 μm resolution limit. As a consequence, a high throughput of 25 wafers/min was achieved, which was more than 25 times higher than that of electron beam (EB) lithography.


2021 ◽  
pp. 105906
Author(s):  
Yu-qiong Gao ◽  
Jin-qiang Zhou ◽  
Yan-yan Rao ◽  
Han Ning ◽  
Jia Zhang ◽  
...  

Metals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1904
Author(s):  
Kyeong Woo Chung ◽  
Ho-Sung Yoon ◽  
Chul-Joo Kim ◽  
Ho-Seok Jeon

This paper proposes selective leaching of molybdenum from Mo/Cu complex bulk concentrates in a 5 M NaCl solution using the electro-oxidation method. Here, the effects of several factors such as pH, pulp density, current density, and temperatures were investigated. A higher leaching yield of Mo increased with increasing pH from 5 to 9 and decreased with increasing pulp density from 1 to 10%. A rise in current density did not help enhance Mo, and the elevating temperature did not always result in a higher leaching yield. Application of ultrasonic led to higher leaching yield of Mo. Ninety-two percent of leaching yield was obtained upon leaching of Mo in 5 M NaCl at 25 °C, pulp density of 5%, and the current density of 0.292 A/g under ultrasonic irradiation with a power of 27 kW. The resultant residue mainly consisted of chalcopyrite.


Author(s):  
masahiro tahashi ◽  
Akikazu Nanbu ◽  
Hiroyuki Yamada ◽  
Makoto Takahashi ◽  
Hideo Goto ◽  
...  

Abstract We previously reported that a swollen gel possessing a uniform composition and prolonged stability can be conveniently prepared by simple ultrasonic irradiation of an ethanol suspension of calcium acetate, which is poorly soluble in ethanol. In this study, the same gel synthesis method was applied to prepare the multicomponent oxide (Pr1−yYy)1−xCaxCoO3 (PYCCO), which undergoes a metal-insulator phase transition. Calcination of the Pr–Y–Ca–Co swollen gel at 800 °C for 12 h in air afforded PYCCO nanoparticles with good crystallinity, representing a faster and more convenient route compared with conventional solid-phase reaction methods or sol–gel methods.


2021 ◽  
Author(s):  
Hourieh Sadat Oboudatian ◽  
Javad Safaei-Ghomi

Abstract Fibrous nano-silica sphere (KCC-1) has appeared as a good and efficient catalyst for ultrasonic irradiation conditions in chemical reactions. This catalyst has the unique properties such as a fibrous surface morphology, high surface area and high mechanical stability. The results indicated that the KCC-1 nanocatalyst could be used as high-performance catalysts under high temperature and pressure condition in organic reaction under ultrasonic irradiation. Morphology, structure, and composition of the fibrous nano-silica sphere were described by N2 adsorption–desorption analysis, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray powder diffraction (XRD), thermogravimetric analysis (TGA) and Fourier-transform infrared spectroscopy (FT-IR). In this work, we used KCC-1@NH2 nanosilica as a basic catalyst for the preparation of chromenes under ultrasonic irradiation conditions for the first time. The recyclability, nontoxicity and high stability of the catalyst, combined with low reaction times and excellent yields, make the present protocol very useful for the synthesis of the title products under ultrasonic conditions. The produced products were confirmed via 1H NMR, 13C NMR, FT-IR analysis.


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