Microwave Heating
Mostrando 13-24 de 102 artigos, teses e dissertações.
-
13. Synergistic Effect of 4A Zeolite from Rice Husk Ash without Aging Time and Silane on the Adhesion Properties of a Warm Mix Asphalt
4A Zeolite was synthesized using rice husk ash (RHA) as a raw material in a microwave-assisted hydrothermal synthesis. Two new procedures were proposed: procedure A, using RHA as the raw material, and procedure B, using the depolymerized RHA. Both procedures were performed using microwave-assisted hydrothermal synthesis, and neither synthesis required an agi
J. Braz. Chem. Soc.. Publicado em: 2018-01
-
14. Effective Synthesis of Silicon Carbide Nanotubes by Microwave Heating of Blended Silicon Dioxide and Multi-Walled Carbon Nanotube
Silicon carbide nanotube (SiCNTs) has been proven as a suitable material for wide applications in high power, elevated temperature and harsh environment. For the first time, we reported in this article an effective synthesis of SiCNTs by microwave heating of SiO2 and MWCNTs in molar ratio of 1:1, 1:3, 1:5 and 1:7. Blend of SiO2 and MWCNTs in the molar ratio
Mat. Res.. Publicado em: 18/09/2017
-
15. Microwave-Assisted Oxidation of Organic Matter Using Diluted HNO 3 under O 2 Pressure: Rationalization of the Temperature Gradient Effect for Acid Regeneration
Oxidation using diluted HNO3 solution is dependent on reactions taking place in the gas phase, resulting in HNO3 regeneration, thus allowing sub stoichiometric reactions (16.7 mmol of C oxidized with 10.4 mmol of HNO3). Reactions for HNO3 regeneration are dependent on temperature gradient along reaction vessel. Thermographic images were obtained of external
J. Braz. Chem. Soc.. Publicado em: 2017-09
-
16. Effect of Heating Method on Microstructure and Mechanical Properties of Zircon Reinforced Aluminum Composites
The mechanical properties and microstructure of aluminum matrix composites containing of zircon (10, 15 and 20 wt.%) as a reinforcement particles and cobalt additive (1, 1.5 and 2 wt.%) were investigated. The aluminum matrix composites were prepared by powder metallurgy technique and sintered in both conventional and microwave furnaces at temperatures higher
Mat. Res.. Publicado em: 10/11/2016
-
17. Method Development and Total Uncertainty Estimation for Boron, Sulfur and Phosphorus Determination in Mineral Fertilizer Using ICP OES
This study deals with B, S, and P determination in mineral fertilizer and S in commercial sulfur-formulation using inductively coupled plasma optical emission spectrometry. According to multivariate optimization using a Doehlert matrix, the analytes extraction in fertlizer can be conducted in open flask and heating on hot plate or in closed flask in microwav
J. Braz. Chem. Soc.. Publicado em: 2016-11
-
18. Selective Synthesis of (Z)-Chalcogenoenynes and (Z,Z)-1,4-bis-Chalcogenbuta-1,3-dienes Using PEG-400
We present here our results on the temperature controlled, selective hydrochalcogenation of 1,4-diorganyl-1,3-butadiynes with nucleophilic species of selenium, tellurium and sulfur generated in situ from the respective diaryl dichalcogenide and NaBH4. Using polyethylene glycol (PEG)-400 at 30 ºC the (Z)-chalcogenoenynes are obtained and at 90 ºC the (Z,Z)-
J. Braz. Chem. Soc.. Publicado em: 2016-11
-
19. DETERMINAÇÃO SIMULTÂNEA DE METAIS E ENXOFRE POR ICP-OES EM RESÍDUOS DE DESTILAÇÃO DE PETRÓLEO
A method for digestion of crude oil distillation residues (atmospheric residue, AR and vacuum residue, VR) using microwave-induced combustion (MIC) was developed for simultaneous determination of metals (Ba, Co, Fe, Mg, Mn, Ni and V) and sulfur by inductively coupled plasma optical emission spectrometry (ICP-OES). Samples were wrapped in polyethylene films a
Quím. Nova. Publicado em: 2016-11
-
20. Evaluating the "Tape Tea" Myth as Low Cost Abuse Drug through Mass Spectrometry
The role of the "tape tea" as a low cost abuse drug is evaluated, by searching for possible inorganic and organic compounds after its preparation. Two energy sources are evaluated (conventional and microwave heating) for preparing the "tape tea" using new or used cassette (K7) or video home system (VHS) tapes. After optimizing all the inductively coupled pla
J. Braz. Chem. Soc.. Publicado em: 2016-10
-
21. Microwave-assisted Synthesis of a ZrC-SiC Nanocomposite by Carbothermal Reduction and its Effect on Mean Particle Size
ZrC-SiC nanopowders were prepared by carbothermal reduction of ZrO2 and SiO2 with carbon black in argon gas atmosphere, using microwave energy as an alternative heating source. The samples were characterized by XRD, SEM and BET surface area analysis. The results indicate that highly crystalline ZrC-SiC composites with a mean particle size of about 80 nm can
Mat. Res.. Publicado em: 04/08/2016
-
22. Microwave Assisted Combustion Synthesis and Characterization of Nanocrystalline Nickel-doped Cobalt Ferrites
Abstract Nanoparticles nickel-doped cobalt ferrites [NixCo1-xFe2O4 (x = 0.0, 0.25, 0.50, 0.75 and 1.0 of Ni2+)] were prepared by the microwave combustion synthesis, using a stoichiometric mixture of metal nitrates and urea as the oxidizer and fuel to drive the reaction. The effect of microwave irradiation on the phase composition was favorable to promote the
Mat. Res.. Publicado em: 01/08/2016
-
23. Generation of Volatile Compounds from Carotenoids of Dunaliella bardawil Algae by Water Bath Heating and Microwave Irradiation
The volatile compounds formed by thermal degradation of the carotenoids present in Dunaliella bardawil were investigated by microwave irradiation (MW) and water bath heating (WB) in different conditions of temperature and time using central composite design. Volatiles extraction by solid phase microextraction (SPME) was optimized and performed at 40 °C for
J. Braz. Chem. Soc.. Publicado em: 2016-08
-
24. Derivatives of Cardanol through the Ene Reaction with Diethyl Azodicarboxylate
Cardanol is an alkyl/alkenyl phenolic material obtained from cashew nut shell liquid (CNSL), which is a byproduct of cashew nut processing. In an effort to develop new uses, cardanol was derivatized for the first time with diethyl azodicarboxylate (DEAD) through the ene reaction. The reaction was facile and required only the application of heat without a cat
J. Braz. Chem. Soc.. Publicado em: 2016-06