Influence of Sodium Hydroxide on the Properties of FGD Gypsum-Slag Composite Materials

2014 ◽  
Vol 675-677 ◽  
pp. 750-755
Author(s):  
Fang Huang ◽  
Bao Long Jiao ◽  
Dong Dong Wang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Composite Materials ◽  
Flexural Strength ◽  
Sodium Hydroxide ◽  
Setting Time ◽  
Maximal Strength ◽  
Action Mechanism ◽  
Fgd Gypsum ◽  
Scanning Electron

By examining the compressive and flexural strength of composite and using scanning electron microscopy (SEM), we analyzed the influence of sodium hydroxide on the properties of FGD gypsum and slag composite materials and discussed the influence of sodium hydroxide on the setting time and mechanical strength of the composite materials and presented the action mechanism of sodium hydroxide as a stimulator. The results show that when the content of sodium hydroxide was percent of 0.25, the maximal strength of FGD gypsum-slag composite materials was reached.

Effect of BN Short Fiber Content on Mechanical Properties of ZrB2-SiC UHTCs

2012 ◽  
Vol 512-515 ◽  
pp. 706-709 ◽  
Author(s):  
Chang Ling Zhou ◽  
Yan Yan Wang ◽  
Zhi Qiang Cheng ◽  
Chong Hai Wang ◽  
Rui Xiang Liu
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Fracture Toughness ◽  
Scanning Electron Microscopy ◽  
Flexural Strength ◽  
Hot Pressing ◽  
Ceramic Composites ◽  
Short Fiber ◽  
Hot Pressing Sintering ◽  
Scanning Electron

ZrB2-20%volSiC ceramic composites with different volume of BN short fiber were fabricated by the hot-pressing sintering under 2000°C. The content of BN short fiber changed from 0 to 15vol%. The density, flexural strength, fracture toughness and thermal expansions coefficient were studied. The microstructures of the samples were observed by scanning electron microscopy. The results show that the introducing of BN short fiber into the ZrB2-20%volSiC lead to a serious of change to the mechanical properties of the ceramic. When the content of the BN short fiber is 10vol%, the flexural strength and fracture toughness reach 422.1MPa and 6.15 MPa•m 1/2 respectively. And the mechanism of the increasing toughness was studied.

scholarly journals Influence of the Treatment Temperature on the Microstructure and Hydration Behavior of Thermoactivated Recycled Cement

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 3937
Author(s):  
Sofia Real ◽  
Ana Carriço ◽  
José Alexandre Bogas ◽  
Mafalda Guedes
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Mechanical Strength ◽  
Water Demand ◽  
Isothermal Calorimetry ◽  
Setting Time ◽  
Treatment Temperature ◽  
Diffraction Field ◽  
Resonance Spectroscopy ◽  
Scanning Electron

This paper intends to contribute to a better knowledge of the production and rehydration of thermoactivated recycled cement and its incorporation in cement-based materials. To this end, the influence of the treatment temperature on the properties of recycled cements and recycled cement pastes was assessed by means of a wide array of tests. Anhydrous recycled cement as well as the resulting pastes were characterized through density and particle size, water demand and setting time, thermogravimetry, X-ray diffraction, field emission gun scanning electron microscopy, isothermal calorimetry, 29Si nuclear magnetic resonance spectroscopy, flowability, mechanical strength, mercury intrusion porosimetry and scanning electron microscopy. The treatment temperature had a significant influence on the dehydration and hydration of recycled cement, essentially resulting in the formation of C2S polymorphs of varying reactivity, which led to pastes of different fresh and hardened behaviors. The high water demand and the pre-hydration of recycled cement resulted in high setting times and low compressive strengths. The highest mechanical strength was obtained for a treatment temperature of 650 °C.

scholarly journals Properties of Luffa Fiber Reinforced PHBV Biodegradable Composites

Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1765 ◽  
Author(s):  
Yong Guo ◽  
Li Wang ◽  
Yuxia Chen ◽  
Panpan Luo ◽  
Tong Chen
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Flexural Strength ◽  
Room Temperature ◽  
Moisture Resistance ◽  
Hot Press ◽  
Biodegradable Composites ◽  
Hot Press Forming ◽  
Pre Treatment ◽  
Scanning Electron

In this study, composites of poly (hydroxybutyrate-co-valerate) (PHBV) with untreated luffa fibers (ULF) and NaOH-H2O2 treated luffa fibers (TLF) were prepared by hot press forming. The properties of luffa fibers (LFs) and composites were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and other analysis methods. Results showed that pre-treatment effectively removed pectin, hemicellulose, and lignin, thus reducing the moisture absorptivity of LFs. The flexural strength of TLF/PHBV was higher than that of ULF/PHBV. With 60% LF content, the flexural strengths of ULF/PHBV and TLF/PHBV reached 75.23 MPa and 90.73 MPa, respectively, 219.7% and 285.6% more than that of pure PHBV. Water absorptivities of composites increased with increase in LF content. Water absorptivity of TLF/PHBV was lower than that of ULF/PHBV. The flexural strengths of composites decreased after immersion in water at room temperature. Meanwhile, flexural strength of TLF/PHBV was lower than that of ULF/PHBV. Pretreatment of LFs effectively improved the bonding between fibers and PHBV, resulting in enhanced and thus improved the moisture resistance of composites.

Influence of Foaming Agent on Properties of Red Mud Lightweight Baking-Free Brick

2014 ◽  
Vol 541-542 ◽  
pp. 388-391
Author(s):  
Long Ma ◽  
Guo Zhong Li
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Compressive Strength ◽  
Fly Ash ◽  
Flexural Strength ◽  
Red Mud ◽  
Micro Structure ◽  
Foaming Agent ◽  
Scanning Electron

Red mud lightweight baking-free brick was prepared by red mud, fly ash and cement, mixed with a certain amount of activator agent and foaming agent. The influence of foaming agent on properties of red mud lightweight baking-free brick was studied. The micro-structure of red mud lightweight baking-free brick was characterized by scanning electron microscopy (SEM). The results show that when the foaming agent content is 10ml, the sample with better performance obtained and the density is 423kg/m3, flexural strength is 0.49MPa and compressive strength is 1.87MPa.

Biopolymer Encapsulation of PEI-Derivatives for Heavy Metal Sorption

2015 ◽  
Vol 1130 ◽  
pp. 529-532
Author(s):  
Caroline Bertagnolli ◽  
Thierry Vincent ◽  
Eric Guibal
Keyword(s):  
Electron Microscopy ◽  
Heavy Metal ◽  
Scanning Electron Microscopy ◽  
Composite Materials ◽  
Metal Sorption ◽  
Initial Concentration ◽  
Heavy Metal Sorption ◽  
Maximum Sorption ◽  
Complex Solutions ◽  
Scanning Electron

Composite materials have been synthesized by alginate or chitosan encapsulation of polyethylenimine (PEI) derivatives (obtained by glutaraldehyde grafting of histidine and carbon disulfide). Discrete or agglomerated PEI-derivative particles are immobilized in the macroporous network of biopolymer matrix (as shown by scanning electron microscopy and SEM-EDX analysis). The effect of pH and initial concentration on Zn (II) and Cu (II) sorption performance were analyzed. The incorporation of PEI-derivatives biopolymer matrix improves sorption performance in complex solutions (doped with CaCl2) compared to pristine biopolymer. Maximum sorption capacities range from 0.64 to 1 mmol L-1 for Zn (II) and from 1.13 to 1.67 mmol L-1 for Cu (II).

Preparation and Study on the Performance of Glazed Hollow Beads Thermal Insulation Materials

2013 ◽  
Vol 662 ◽  
pp. 335-338
Author(s):  
Xiao Long Li ◽  
Guo Zhong Li
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Thermal Insulation ◽  
Material Properties ◽  
Cementitious Materials ◽  
Insulation Material ◽  
Action Mechanism ◽  
Molding Process ◽  
Internal Morphology ◽  
Scanning Electron

The glazed hollow beads thermal insulation board was made of glazed hollow beads and perlite by selecting cement and fly ash as cementitious materials, and adding appropriate amount of VAE emulsion and fibers, in the compression molding process. In this paper, the influence of different dosages of perlite replacing vitrified beads, VAE emulsion and fiber on the material properties were studied. Besides, the internal morphology of the sample was observed by scanning electron microscopy, and the action mechanism of the insulation material was explored.

STUDY OF MECHANICAL PROPERTIES AND FRACTURE MODE OF ALUMINA-SILICON CARBIDE NANOCOMPOSITES

2012 ◽  
Vol 05 ◽  
pp. 551-558 ◽  
Author(s):  
A. RAHIMNEZHAD YAZDI ◽  
H.R. BAHARVANDI ◽  
H. ABDIZADEH ◽  
N. EHSANI
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Silicon Carbide ◽  
Flexural Strength ◽  
Fracture Mode ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sic Particles ◽  
Scanning Electron

In this study Al 2 O 3- SiC nanocomposites have been fabricated by mixing of alumina and silicon carbide nano powders, followed by hot pressing at 1700°C. The mechanical properties and fracture mode of Al 2 O 3- SiC nanocomposites containing different volume fractions (5, 10 and 15%) of nano scale SiC particles were investigated and compared with those of alumina. Al 2 O 3- SiC powders were prepared by planetary milling in isopropanol. Fracture mode of specimens was investigated by means of scanning electron microscopy. Nanocomposites were tougher than alumina when they were hot pressed at the same temperature, and the values of nanocomposite's flexural strength and hardness were higher than those of alumina. Flexural strength, hardness and fracture toughness of the nanocomposites increase by increasing the volume percent of SiC up to 10% and then decrease slightly. The Scanning electron microscopy observations showed that fracture mode changes from intergranular for alumina to transgranular for nanocomposites. Finally X-ray diffraction analysis couldn't detect any chemical reactions between Al 2 O 3 and SiC particles.

Arg-substituted VmCT1 analogs reveals promising candidate for the development of new antichagasic agent

Parasitology ◽  
2020 ◽  
Vol 147 (14) ◽  
pp. 1810-1818
Author(s):  
Cibele Nicolaski Pedron ◽  
Katielle Albuquerque Freire ◽  
Marcelo Der Torossian Torres ◽  
Dânya Bandeira Lima ◽  
Marília Lopes Monteiro ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Flow Cytometry ◽  
Mammalian Cells ◽  
Rational Design ◽  
Membrane Damage ◽  
Action Mechanism ◽  
Promising Candidate ◽  
Cell Death Pathway ◽  
Scanning Electron

AbstractVmCT1 is an antimicrobial peptide (AMP) isolated from the venom of the scorpion Vaejovis mexicanus with antimicrobial, anticancer and antimalarial activities, which the rational design with Arg-substitution has yielded AMPs with higher antimicrobial activity than VmCT1. Chagas is a neglected tropical disease, becoming the development of new antichagasic agents is urgent. Thus, we aimed to evaluate the antichagasic effect of VmCT1 and three Arg-substituted analogues, as well their action mechanism. Peptides were tested against the epimastigote, trypomastigote, amastigote forms of Trypanossoma cruzi Y strain and against LLC-MK2 mammalian cells. The mechanism of action of these peptides was evaluated by means of flow cytometry and scanning electron microscopy. VmCT1 presented activity against all three forms of T. cruzi, with EC50 against trypomastigote forms of 1.37 μmol L−1 and selectivity index (SI) of 58. [Arg]3-VmCT1, [Arg]7-VmCT1 and [Arg]11-VmCT1 also showed trypanocidal effect, but [Arg]11-VmCT1 had the best effect, being able to decrease the EC50 against trypomastigote forms to 0.8 μmol L−1 and increase SI to 175. Necrosis was cell death pathway of VmCT1, as well [Arg]7-VmCT1 and [Arg]11-VmCT1, such as observed by membrane damage in flow cytometry analyses and scanning-electron-microscopy. In conclusion, [Arg]11-VmCT1 revealed promising as a candidate for new antichagasic therapeutics.

The structure of reaction wood as indicated by scanning electron microscopy

1969 ◽  
Vol 17 (3) ◽  
pp. 391 ◽  
Author(s):  
G Scurfield ◽  
S Silva
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Sodium Hydroxide ◽  
Osmic Acid ◽  
Reaction Wood ◽  
Chemical Treatments ◽  
Before And After ◽  
Cupressus Arizonica ◽  
S2 Layer ◽  
Scanning Electron

Scanning electron microscopy was used to investigate the structure of normal and reaction wood of Cupressus arizonica Greene, Pinus canariensis C. Sm., and P. radiata D. Don. The wood of P. radiata was examined before and after various chemical treatments. These included chlorine water-sodium hydroxide, glacial acetic acid-hydrogen peroxide, sodium hydroxide-sodium sulphide, 17.5 % sodium hydroxide, 78 % phosphoric acid, 72 % sulphuric acid, 1 % osmic acid, and 2% potassium permanganate. The helical ribs of the S2 layer in reaction wood cells appeared to be multistranded. Warts tended to become fewer and restricted to the grooves in the S2 layer during the change-over from normal to reaction wood cells. The origin and chemical composition of the warts and associated membrane are considered.

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