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Jurnal Tekno ◽  
2021 ◽  
Vol 18 (2) ◽  
pp. 71-80
Author(s):  
Kiagus Ahmad Roni

Transesterification of oil with alcohol produces glycerol and methyl esters (biodiesel). The reaction is influenced, among others, by the amount of catalyst and the ratio of oil and meth hanol reagents. This purpose of research to determine the effect of the amount of catalyst and the ratio of reagents on the conversion of glycerol. The experiment was carried out in a three-necked flask equipped with a stirrer and reverse cooling. In a three-necked flask, 150 ml of castor oil was added, 0.375 ml of H2SO4 was added, heated to a temperature of 650C. Then add 185 ml of methanol and stir for 30 minutes. Then let stand 24 hours to form two layers. The bottom layer is glycerol. The transesterification process was continued by adding 100 ml of glycerol in a mixture of methanol (variation 1:2, 1:3, 1:4) with RCC catalyst (variation 1.7gr;1.9gr;2.1gr;2.3gr ;2.5gr) The mixture was then stirred at 90 rpm for 75 minutes. Based on the results of research conducted, the highest glycerol conversion value was in the amount of catalyst 2.1 g with a ratio of reagents between castor oil and methanol of 1:3 of 55.33%.


2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Bingbing Yan ◽  
Chuanying Zhang

With the continuous popularization of smart medicine, the protective effect of silibinin in the liver has attracted much attention. This study mainly explores the liver protection mechanism and absorption promotion technology of silybin based on intelligent medical analysis. Refining of silibinin: accurately weigh 1.0 g of silibinin in a three-necked flask; gradually add 50 mL of anhydrous methanol, reflux and filter the precipitated solid; and weigh it after drying. ICR male mice were taken as experimental subjects and randomly divided into groups of 10 each. The mice in the normal group and the model group were given intragastrically with 0.5% CMC-Na solution; the mice in the silibinin group were given intragastrically with SB/CMC-Na suspension; the mice in the remaining groups were given low, medium, and high-dose suspensions to their stomachs, and silibinin 23 acylate/CMC-Na suspension was administered at a dose of 10 mL/kg for 7 consecutive days. After that, the mice were fasted for 12 hours. After 6 hours of fasting (18 hours after modeling), the blood cells from their orbits were taken, placed in a 37°C water bath for 30 minutes, and centrifuged at 4000 rpm for 10 minutes, and then the serum was taken; the activity equivalent of AST and ALT in serum was measured; serum determination Medium AST and ALT vitality. The mice were killed by decapitation, fresh liver tissue was immediately collected, and part of it was frozen in liquid nitrogen for the RT-PCR test. The hepatocyte expansion and death were observed using a transmission electron microscope, and the oncosis index (OI) was calculated. Another part of the liver tissue was fixed in 4% paraformaldehyde solution, embedded in paraffin, dehydrated, and sliced at 4 μm. Some sections were stained with conventional HE, and the pathological changes of liver cells were observed under light microscope; some sections were subjected to immunohistochemistry. Only one mouse died when 240 mg/kg of silibinin was given 10 minutes after the model was modeled. However, when 240 mg/kg silibinin was given to the mice 20 minutes after modeling, the mortality rate of the mice rose to 50%, and the therapeutic effect was significantly weakened. This research is helpful to advance the research of silybin in liver protection.


2020 ◽  
Vol 5 (2) ◽  
pp. 108
Author(s):  
Boy Chandra Sitanggang ◽  
Zainal Abidin

High electrical conductivity material Fe-Chitosan Schiff base produced via two stages mechanism, reaction of salicylaldehyde and chitosan in three necked flask following the formation of complex by soak Chitosan Schiff base in FeCl3 solution in various times. The formed Schiff base was confirmed by presence of imine at 1604.77 cm-1. Next, Fe absorption was analyzed by using ICP-MS gives highest results at 492,51 ppm at 5 hours immersion time. The electrical conductivity exhibit tendency to increase and the highest point at 3.5 x 10-6 S cm­-1


2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Huashan Yang ◽  
Yujun Che

The agglomeration of nano-CaCO3 (NC) is the largest bottleneck in applications in cementitious materials. If nano-CaCO3 modifies the surface of micron-scale limestone powder (LS), then it will form nano-CaCO3/limestone composite particles (NC/LS). It is known that micron-scale limestone is easily dispersed, and the “dispersion” of NC is governed by that of LS. Therefore, the dispersion of nano-CaCO3 can be improved by the NC/LS in cementitious materials. In this work, the preparation of NC/LS was carried out in a three-necked flask using the Ca(OH)2-H2O-CO2 reaction system. The morphology of NC/LS was observed by a field emission scanning electron microscope (FE-SEM). The effects of NC/LS on the hydration products and pore structure of cementitious materials are proposed. 5% NC/LS was added into cement paste and mortar, and the mechanical properties of the specimens were measured at a certain age. Differential scanning calorimetry (DSC), thermal gravimetric analysis (TG), and backscattered electron imaging (BSE) were conducted on the specimens to investigate the hydration products and pore structure. The properties of specimens with NC/LS were compared to that of control specimens (without NC/LS). The results revealed that NC/LS reduced the porosity and improved the mechanical properties of the cementitious materials.


2018 ◽  
Vol 154 ◽  
pp. 01033 ◽  
Author(s):  
Hendrik Setiawan ◽  
Himawan T.B.M. Petrus ◽  
Indra Perdana

Lithium-ion batteries (LIBs) are secondary rechargeable power sources which increasing production also leads to large amount of waste. In order to environmentally friendly reduce the waste, this work aimed to use acetic acid as a substitute leaching agent to leach Co metals which constitutes about 72.39% wt of the battery cathode. The leaching process was done in a three-necked-flask where calcined LIB cathode powder was mixed with acetic acid solution. The variables of the leaching process under investigation were solution pH, concentration of H2O2 in the solution, S/L ratio, temperature and reaction time. Experimental results showed that only temperature significantly influenced the leaching rate of Co. Since the process was exothermic, the maximum recovery decreased as temperature increased. Conventional shrinking core model that considers diffusion and irreversible surface reaction resistances was found not sufficient to predict the kinetics of the Co leaching with acetic acid. A more representative kinetics model that considers a reversible reaction of Co complex formation needs to be further developed.


2016 ◽  
Vol 23 (4) ◽  
pp. 401-406 ◽  
Author(s):  
Yu Guo ◽  
Yan-qing Wang ◽  
Zhong-ming Wang ◽  
Cheng-jin Shen

AbstractThis article reports on experiments aimed at modifying nanosilica powder by adding a silane coupling agent, KH570, to achieve high dispersibility and strengthen the compatibility and interface bonding between it and the organic phases. Experiments were first done to prepare the common nanosilica powder, dried at 120°C for 4 h in a drying oven; second, an ethanol/water solution (volume ratio 11:1, total volume not more than two-thirds of the capacity of the flask) was blended in a three-necked flask with a reflux condenser and magnetic stirring; third, appropriate amount of dried nanosilica powder and appropriate mass fraction ratio of the silane coupling agent KH570 were added into the ethanol/water solution, and the pH of the mixture was adjusted to about 4–5 by adding acetic acid solution; fourth, the three-necked flask was placed in a water bath, and the modification reaction of the above mixing solution was sustained for an appropriate time in the appropriate temperature with magnetic stirring; fifth, the above mixing solution was separated by using a centrifuge (10,000 rpm) for 3 min, and the precipitate at the bottom of the flask was obtained after the supernatant was poured out; sixth, the precipitate was dried at 120°C for 48 h in a drying oven after it was washed with acetone several times, finally yielding the high-dispersibility nanosilica powder. The orthogonal test method was adopted to optimize three key test parameters: mass fraction ratio of the silane coupling agent KH570, modification reaction temperature, and modification reaction time. The dispersion effect of the high-dispersibility nanosilica powder was characterized by using infrared, X-ray diffraction, and scanning electron microscopic analyses from different views. The results revealed that the best dispersibility effect was achieved when the mass fraction ratio of the silane coupling agent KH570 was 3%, the modification reaction temperature was 80°C, and the modification reaction time was 2 h. Furthermore, the modification reaction resulted in chemical bonding, but not simple physical adsorption, owing to the presence of organic bond groups in the nanosilica modified by the silane coupling agent. The crystal structure of the nanosilica powder remained amorphous after the modification reaction.


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