Effect of Bentonite on the Structure and Performance of Sodium Alginate as Microsphere Carrier of Essential Oil

2022 ◽  
Vol 905 ◽  
pp. 271-276
Author(s):  
Hui Wang ◽  
Cong Ying Hou ◽  
Yan Bai
Keyword(s):  
Essential Oil ◽  
Sodium Alginate ◽  
Loss Rate ◽  
Mass Loss Rate ◽  
Interlayer Spacing ◽  
Xrd Analysis ◽  
Cinnamon Oil ◽  
Single Carrier ◽  
And Performance ◽  
Composite Carrier

The effect of bentonite (BT) on the structure and performance of sodium alginate (SA) as microsphere carrier of essential oil is studied. The addition of BT can improve the performance of alginate gel microspheres through the study of the properties of single carrier SA and composite carrier SA/BT. The experimental results show that the viscosity of composite carrier SA/BT solution is higher than that of carrier SA solution, and the increasing rate of viscosity of composite solution with temperature is less than that of SA. The addition of BT can effectively inhibit the swelling of SA microspheres. The hydrogen bonding between SA and BT is shown in FTIR, and the interlayer spacing of BT crystal structure is not changed in XRD analysis. The mass loss rate of SA/BT microspheres is lower than that of SA in TGA analysis. The more dense structure of SA/BT microspheres than that of SA microspheres is confirmed by SEM. The release rate of cinnamon oil in SA/BT gel microspheres is significantly lower than that in SA gel microspheres under different temperature conditions. The addition of BT could better control the volatilization of essential oil encapsulated in SA gel microspheres.

Chitosanase Immobilization Using Composite Carrier of Sodium Alginate/Cellulose

2011 ◽  
Vol 236-238 ◽  
pp. 2371-2377 ◽  
Author(s):  
Yan Wang ◽  
Chen Lu Zhang ◽  
Ping Li ◽  
Pei Gen Zhou ◽  
Xiao Rong Pan
Keyword(s):  
Thermal Stability ◽  
Sodium Alginate ◽  
Industrial Production ◽  
Free Enzyme ◽  
Optimum Ratio ◽  
Single Carrier ◽  
Km Value ◽  
Composite Carrier

Sodium alginate and cellulose were combined to use as a composite carrier forPseudomonassp. CUY8 chitosanase immobilization. For free enzyme, immobilized chitosanase within different carriers of sodium alginate and composite carrier, Km values were 1.919, 9.27, and 5.91µM, respectively. The increase of Km value of immobilized chitosanase with composite carrier was lower than that of single carrier. This indicates that the composite carrier of sodium alginate/ cellulose improves the affinity of chitosanase to the substrate. Furthermore, chitosanase immobilization using composite carrier shows improved thermal stability ranging from 65 to 80°C, and enzyme residual activities were more than 75%. The effects of ratio of enzyme to substrate on chitooligosaccharides (COS) production were determined, and COS yields with composite carrier was 68% at optimum ratio of 1:1. Since the immobilization process using composite carrier is simple and effective, this method could be used for the industrial production of COS.

scholarly journals Corrosion Performance of Nano-TiO2-Modified Concrete under a Dry–Wet Sulfate Environment

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5900
Author(s):  
Chao Xu ◽  
Hao-Hao Liao ◽  
You-Liang Chen ◽  
Xi Du ◽  
Bin Peng ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Mass Loss ◽  
Loss Rate ◽  
Mass Loss Rate ◽  
Peak Stress ◽  
Xrd Analysis ◽  
Concrete Surface ◽  
Test Results ◽  
Nano Tio2 ◽  
Ordinary Concrete

This study compared the effects of the sulfate dry–wet cycle on the properties of ordinary concrete and nano-TiO2-modified concrete, including the mass loss rate, ultrasonic wave velocity, compressive strength, and XRD characteristics. In addition, a series of compression simulations carried out using the PFC2D software are also presented for comparison. The results show the following: (1) with an increase in dry–wet cycles, the damage to the concrete gradually increased, and adding nano-TiO2 into ordinary concrete can improve the material’s sulfate resistance; (2) after 50 sulfate dry–wet cycles, the mass loss rate of ordinary concrete was –3.744%, while that of nano-TiO2-modified concrete was −1.363%; (3) the compressive strength of ordinary concrete was reduced from 41.53 to 25.12 MPa (a reduction of 39.51%), but the compressive strength of nano-TiO2-modified concrete was reduced from 49.91 to 32.12 MPa (a reduction of 35.64%); (4) after a sulfate dry–wet cycle, the nano-TiO2-modified concrete surface produced white crystalline products, considered to be ettringite based on the XRD analysis; (5) when considering the peak stress and strain of the concrete samples, the numerical results agreed well with the test results, indicating the reliability of the method.

scholarly journals SN 2009ip: CONSTRAINTS ON THE PROGENITOR MASS-LOSS RATE

2013 ◽  
Vol 768 (1) ◽  
pp. 47 ◽  
Author(s):  
E. O. Ofek ◽  
L. Lin ◽  
C. Kouveliotou ◽  
G. Younes ◽  
E. Göğüş ◽  
...  
Keyword(s):  
Mass Loss ◽  
Loss Rate ◽  
Mass Loss Rate

scholarly journals AGB Winds with Gas-Dust Drift in Stellar Evolution Codes

Universe ◽  
2021 ◽  
Vol 7 (5) ◽  
pp. 113
Author(s):  
Lars Mattsson ◽  
Christer Sandin
Keyword(s):  
Stellar Evolution ◽  
Loss Rate ◽  
Mass Loss Rate ◽  
Carbon Star ◽  
Intermediate Mass ◽  
Future Directions ◽  
Physical Description ◽  
Intermediate Mass Stars ◽  
Dust Component ◽  
Improved Model

A significant fraction of new metals produced in stars enter the interstellar medium in the form of dust grains. Including dust and wind formation in stellar evolution models of late-stage low- and intermediate-mass stars provides a way to quantify their contribution to the cosmic dust component. In doing so, a correct physical description of dust formation is of course required, but also a reliable prescription for the mass-loss rate. Here, we present an improved model of dust-driven winds to be used in stellar evolution codes and insights from recent detailed numerical simulations of carbon-star winds including drift (decoupling of dust and gas). We also discuss future directions for further improvement.

Effect of Sample Width on Downward Flame Spread over Typical Energy Conservation Material at a High Elevation Area

2014 ◽  
Vol 664 ◽  
pp. 199-203 ◽  
Author(s):  
Wei Guang An ◽  
Lin Jiang ◽  
Jin Hua Sun ◽  
K.M. Liew
Keyword(s):  
Mass Loss ◽  
Flame Spread ◽  
Loss Rate ◽  
Mass Loss Rate ◽  
High Elevation ◽  
Flame Height ◽  
Spread Rate ◽  
Flame Spread Rate ◽  
Sample Width ◽  
Downward Flame Spread

An experimental study on downward flame spread over extruded polystyrene (XPS) foam at a high elevation is presented. The flame shape, flame height, mass loss rate and flame spread rate were measured. The influences of width and high altitude were investigated. The flame fronts are approximately horizontal. Both the intensity of flame pulsation and the average flame height increase with the rise of sample width. The flame spread rate first drops and then rises with an increase in width. The average flame height, mass loss rate and flame spread rate at the higher elevation is smaller than that at a low elevation, which demonstrates that the XPS fire risk at the higher elevation area is lower. The experimental results agree well with the theoretical analysis. This work is vital to the fire safety design of building energy conservation system.

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