Quenched
Mostrando 1-12 de 241 artigos, teses e dissertações.
-
1. Temperature Dependent Emission Properties of ReI Tricarbonyl Complexes with Dipyrido-Quinoxaline and Phenazine Ligands
In this work, the emission properties of fac-[Re(CO)3(NN)(py)]+, NN = 1,10-phenanthroline (phen), dipyrido[3,2-f:2’,3’-h]quinoxaline (dpq) and dipyrido[3,2-a:2’3’-c]phenazine (dppz); py = pyridine were investigated in different temperatures, ranging from 80 to 300 K, and in different solvent mixtures and in polymethyl methacrylate. The changes observ
Journal of the Brazilian Chemical Society. Publicado em: 2022
-
2. What is new for 2020
Photophysical processes in multicomponent solutions composed by natural pigments, extracted from Caesalpinia echinata (Brazil-wood) leaves, are investigated. Beacuse of the main fluorescent molecules in these solutions are the chlorophyll a, chlorophyll b and pheophytin a, all features are discussed regarding these three pigments. It is observed that the flu
J. Braz. Chem. Soc.. Publicado em: 2020-01
-
3. Selective Inner-Filter on the Fluorescence Response of Chlorophyll and Pheophytin Molecules Extracted from Caesalpinia echinata Leaves
Photophysical processes in multicomponent solutions composed by natural pigments, extracted from Caesalpinia echinata (Brazil-wood) leaves, are investigated. Beacuse of the main fluorescent molecules in these solutions are the chlorophyll a, chlorophyll b and pheophytin a, all features are discussed regarding these three pigments. It is observed that the flu
J. Braz. Chem. Soc.. Publicado em: 2020-01
-
4. Efeitos da variação da concentração de solução polimérica aquosa a base de PVP na têmpera de aço AISI 4140
RESUMO A têmpera é um tratamento térmico que tem como principal objetivo a elevação de dureza e resistência mecânica dos aços por meio da sua transformação microestrutural. O processo se baseia na elevação da temperatura do material até a austenitização, seguida do arrefecimento por meio da imersão em um fluido, a qual precisa ser rápida o s
Matéria (Rio J.). Publicado em: 16/09/2019
-
5. Hydrothermal Synthesis to Water-stable Luminescent Carbon Dots from Acerola Fruit for Photoluminescent Composites Preparation and its Application as Sensors
Carbon dots (C-dots) possess the attractive properties of high stability, low toxicity, good water solubility, simple synthetic routes as well as size and excitation-dependent photoluminescence (PL).The aim of this work was to synthesize photoluminescent C-dots by hydrothermal method using acerola fruit (Malpighiaemarginata) as a row material, since this fru
Mat. Res.. Publicado em: 06/06/2019
-
6. Effect of the Chemical Homogeneity of a Quenched and Tempered C-Mn Steel Pipe on the Mechanical Properties and Phase Transformations
Seamless steel pipes for application in the oil and gas industries are manufactured from quenched and tempered steel. Aiming to meet the required characteristics, it is necessary that the microstructure and the mechanical properties are homogeneous along the wall thickness of the pipes, which is even more critical for thick wall pipes. Considering the seamle
Mat. Res.. Publicado em: 03/06/2019
-
7. Dependence of Wear and Mechanical Behavior of Nitrocarburized/CrN/DLC Layer on Film Thickness
Diamond-like carbon (DLC) films are amorphous metastable carbon form that provide interesting mechanical and tribological properties. The role of film thickness influence upon wear and mechanical properties is of interest and not yet fully reported. In this study, two samples of previously plasma nitrocarburized, quenched and tempered H13 steel were duplex t
Mat. Res.. Publicado em: 31/01/2019
-
8. Heat Treatment of Sintered Valve Seat Inserts
The characterization of sintered valve seat inserts (VSIs) after being subjected to different heat treatment operations has been carried out. The VSIs were obtained from three different alloys by mixing iron powder with AISI M3:2, AISI M2 high-speed steels, and AISI D2 tool steel. After sintering, the VSI were quenched in air followed by double tempering at
Mat. Res.. Publicado em: 02/08/2018
-
9. Surface Integrity Analisys in the Hard Turning of Cemented Steel AISI 4317
This work was based on the surface integrity analysis of hardened steel, AISI 4317 case carburized, quenched and tempered with 58 HRC, obtained by a turning operation executed with CBN (cubic boron nitride) tool, varying three basic cutting parameters (cutting speed, feed rate and cutting depth). The surface integrity characterization was conducted analyzing
Mat. Res.. Publicado em: 26/07/2018
-
10. Vida a fatiga de uniones soldadas mediante PAW de aceros microaleados al boro
ABSTRACT In the last years microalloyed boron steels have been adopted in the automotive industry to achieve weight reductions. Namely, they are used as load-bearing elements such as pillars and reinforcements, in a quenched and tempered (QT) condition with tensile strength ranging from 800 to 1300 MPa. Dual-Phase (DP) steels have also been introduced in thi
Matéria (Rio J.). Publicado em: 19/07/2018
-
11. Influence of defects on the irreversible phase transition in the Fe-Pd doped with Co and Mn
ABSTRACT The appearance of BCT martensite in Fe-Pd-based ferromagnetic shape memory alloys, which develops at lower temperatures than the thermoelastic martensitic transition, deteriorates the shape memory properties. In a previous work performed in Fe70Pd30, it was shown that a reduction in defects density reduces the non thermoelastic FCT-BCT transformatio
Matéria (Rio J.). Publicado em: 19/07/2018
-
12. Obtención de aceros de baja aleación con diferentes contenidos de Ni y similares microestructuras y propiedades mecánicas
ABSTRACT Low alloy steels are used in many applications in the oil and gas industry. The addition of Ni in these steels improves their low temperature fracture toughness and hardenability, with a low penalty on weldability. However, ISO 15156-2 standard restricts Ni content up to a 1 wt% limit, requiring additional and expensive tests if higher Ni steels are
Matéria (Rio J.). Publicado em: 19/07/2018