Toluene
Mostrando 1-12 de 852 artigos, teses e dissertações.
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1. SYNTHESIS OF TOLUENE DIISOCYANATE URETHANE PREPOLYMER USING CASTOR OIL AND EVALUATION OF MECHANICAL PROPERTIES
This research is the synthesis of urethane prepolymer cast elastomer which had been produced using toluene diisocyanate and castor oil to replace the synthetic polyol, from petroleum origin, and the evaluation of mechanical properties of the polyurethane. The focus was to replace polyol from petroleum to vegetable material looking for renewable resources. Th
Química Nova. Publicado em: 2022
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2. AN ADAPTED UNMANNED AERIAL VEHICLE FOR ENVIRONMENTAL WATER SAMPLING
In this work an unmanned aerial vehicle (UAV) was adapted to be used as an environmental tool to collect water samples of sea, estuary, and mangrove for further analysis by gas chromatography with a mass detector (GC-MS). The sampling automated system was based on a microcontroller, a solenoid valve, and a peristaltic mini-pump that was coupled to a quadcopt
Química Nova. Publicado em: 2022
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3. Through-Bond and Through-Space Interactions in [2,2]Cyclophanes
The interpretation of the distortions of the electron distribution in [2,2]cyclophanes (22-CPs) is controversial. Some studies indicate that there is an accumulation of electron density (ρ) outside the cavity of 22-CPs. The nature of through-space (ts) interaction is still under debate. The relative importance of ts and through-bond (tb) is an open question
J. Braz. Chem. Soc.. Publicado em: 2021-07
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4. The Stabilization of Asphaltenes in Different Crude Fractions: A Molecular Approach
The conditions of petroleum extraction may allow asphaltenes to precipitate, causing deposition that clogs wells, pipes and equipment, consequently reducing productivity. In this work, the solubility parameters and precipitation onset of polar fractions of heavy crudes from Brazilian fields were estimated using a simplified system of n-heptane/toluene mixtur
J. Braz. Chem. Soc.. Publicado em: 2021-04
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5. POLÍMERO DE IMPRESSÃO MOLECULAR PARA O TIACLOPRIDO: UMA INVESTIGAÇÃO TEÓRICA
Thiacloprid (TCP) is a synthetic insecticide, belonging to the class of neonicotinoids (NNCs), which present potential damages to the environment, biodiversity and human health, being necessary its constant monitoring. In this sense, molecularly imprinted polymers (MIPs) have been shown as an excellent alternative for the separation science, since they can r
Quím. Nova. Publicado em: 2020-12
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6. IAO Systematic Review Award 2020
Abstract Background: Cosmetics are part of the daily life of the population, and their use can lead to allergic contact dermatitis. Objectives: To assess the profile of patients diagnosed with allergic contact dermatitis to cosmetics treated at a referral center for 13 years, as well as the characteristics of the clinical picture and allergens involved. M
Int. Arch. Otorhinolaryngol.. Publicado em: 2020-12
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7. Allergic contact dermatitis to cosmetics: retrospective analysis of a population subjected to patch tests between 2004 and 2017,
Abstract Background: Cosmetics are part of the daily life of the population, and their use can lead to allergic contact dermatitis. Objectives: To assess the profile of patients diagnosed with allergic contact dermatitis to cosmetics treated at a referral center for 13 years, as well as the characteristics of the clinical picture and allergens involved. M
An. Bras. Dermatol.. Publicado em: 2020-12
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8. DETERMINATION OF THE PESTICIDES IN WATER USED IN THE CULTURE AND PROCESSING OF POTATOES
The contamination of water bodies by pesticide residues through direct flow, leaching and other methods has motivated the development of analytical methods for the determination of these compounds in water. A vortex-assisted liquid-liquid microextraction method followed by gas chromatography coupled to mass spectrometry for the determination of anilazine, li
Quím. Nova. Publicado em: 2020-09
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9. IMPACTOS DOS BTEX EM ÁREAS URBANAS DA CIDADE DO RIO DE JANEIRO
Most volatile organic compounds (VOC) have adverse effects on human health and the environment and react individually with different velocities and mechanisms to form ozone. The present work determined the concentration of 55 samples of benzene, toluene, ethylbenzene and xylenes (BTEX), an important subgroup of VOC, by active sampling with active carbon cart
Quím. Nova. Publicado em: 20/07/2020
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10. Understanding Solvent/Bixin Interactions by Raman Spectroscopy
In this work, Raman spectroscopy and density functional theory (DFT) calculations have been used in order to understand the nature of the interaction between the carotenoid bixin and organic solvents with dielectric constant varying from ca. 2 (toluene) to ca. 47 (dimethyl sulfoxide). Raman shifts registered for the main carotenoid marker band, the C=C stret
J. Braz. Chem. Soc.. Publicado em: 2020-07
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11. DEEP EUTECTIC SOLVENTS BASED ON BETAINE AND PROPYLENE GLYCOL AS POTENTIAL DENITRIFICATION AGENTS: A LIQUID-LIQUID EQUILIBRIUM STUDY
Abstract Two deep eutectic solvents (DES) based on betaine (B) and propylene glycol (PG) in molar ratios of 1:4 and 1:5 were prepared and their physico-chemical properties were determined. Liquid-liquid equilibria at 298.15 K and atmospheric pressure were determined for 13 quasi-three-component systems with a hydrocarbon (n-hexane, n-heptane, i-octane or tol
Braz. J. Chem. Eng.. Publicado em: 13/01/2020
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12. ENERGY AND EXERGETIC EVALUATION OF THE MULTICOMPONENT SEPARATION OF PETROCHEMICAL NAPHTHA IN FALLING FILM DISTILLATION COLUMNS
Abstract Multicomponent separation of synthetic petrochemical naphtha (hexane, cyclohexane, toluene and xylene) was carried out in a falling film distillation sequence with heat supply using a vapor chamber (thermosyphon). Tests were carried out by varying feed flow rate and temperatures of the feed and the vapor chamber in two ways of heat supply: isotherma
Braz. J. Chem. Eng.. Publicado em: 09/12/2019