Polyethylene
Mostrando 1-12 de 1541 artigos, teses e dissertações.
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1. Per-Aqueous Liquid Chromatography for the Separation of Polar Compounds Preparation and Characterization of Poly(ethylene oxide co dimethylsiloxane) Based Stationary Phase
Poly(ethylene oxide-co-dimethylsiloxane) was thermally immobilized on silica particles-Si(PEO)-to separate small polar compounds with water-rich mobile phases. Poly(ethylene oxide-co-dimethylsiloxane) content on Si(PEO) stationary phase was optimized using a central composite design. Infrared spectroscopy, scanning electron microscopy, and thermogravimetric
Journal of the Brazilian Chemical Society. Publicado em: 2022
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2. Gas permeability and compressive strength evaluation of porous Al2O3 supported membrane
Abstract The aim was to investigate the feasibility of using a device to characterize permeability in porous substrates with low gas flux. Al2O3 supports were prepared by dry pressing using 1 to 3 wt% of polyethylene glycol (PEG) as a pore-forming agent. The green body was partially sintered at 1300 ºC. CO2 gas was used to measure both the pressure loss and
Cerâmica. Publicado em: 2022
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3. DEVELOPMENT AND OPTIMIZATION OF A SPECTROPHOTOMETRIC METHOD WITH CLOUD POINT EXTRACTION FOR DETERMINATION OF GADOLINIUM
This work describes a simple, sensible, and low-cost analytical method, based on cloud-point extraction (CPE) of the surfactant (1,1,3,3-Tetramethylbutyl)phenyl-polyethylene glycol (Triton X-114), for the efficient extraction and sensible determination of gadolinium after its complexation with 1-(2-pyridylazo)-2-naphthol (PAN) and subsequent determination by
Química Nova. Publicado em: 2022
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4. Management of children with functional constipation referred to tertiary care
Abstract Objectives: To describe the management, to compare treatment at initial referral vs. during specialized follow-up, and to describe outcomes of children with functional constipation (FC) referred to a Brazilian tertiary care center. Methods: Retrospective study, including children (4–18 years) with FC followed at a single center from 2006 to 2019
Jornal de Pediatria. Publicado em: 2022
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5. Elemental Chalcogen (Se, S) in PEG-400 to the Synthesis of Seleno- and Thioflavones from 2-Chlorophenyl Ethynyl Ketone and Nucleophilic Species of Chalcogen
An alternative green method was developed for the synthesis of thio-and selenoflavones by the ring closure of 2-chlorophenyl ethynyl ketone with NaHY (Y = S, Se). These nucleophilic chalcogen species were generated in situ using NaBH4 to reduce the elemental chalcogen in the presence of polyethylene glycol-400 (PEG-400). The efficiency of this reaction is st
J. Braz. Chem. Soc.. Publicado em: 2021-08
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6. Trypanocidal Activity and Increased Solubility of Benznidazole Incorporated in PEG 4000 and Its Derivatives
Selecting a polymer depends on its characteristics, the properties of the drug and of the remaining ingredients in the formulation. The drug, when incorporated into a polymeric matrix, can show several advantages when compared with its conventional form. In this context, this work describes the preparation and characterization of polyethylene glycol (PEG 400
J. Braz. Chem. Soc.. Publicado em: 2021-06
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7. ORNAMENTAL PEPPER ON REFLECTIVE BENCH UNDER PROTECTED ENVIRONMENTS
ABSTRACT Plant ambiance studies the environmental condition favorable to plant growth at the initial stage of seedlings or the complete production cycle. This study aimed to evaluate the cultivation of the ornamental pepper ‘Pyramid’ under protected environments and growing benches with and without reflective material. The protected environments consiste
Eng. Agríc.. Publicado em: 2021-05
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8. Incorporation of Fluorescent Dyes in Electrospun Chitosan/Poly(ethylene oxide)
Polymeric films have been increasingly investigated due to the ease of miniaturization and integration in several sensor devices. Films obtained from the electrospinning technique have a controlled diameter and homogeneity, and substances can be incorporated into the polymeric network. Electrospinning fiber of chitosan (Ch) and poly(ethylene oxide) (PEO) was
J. Braz. Chem. Soc.. Publicado em: 2021-05
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9. Trace analysis of environmental endocrine disrupting contaminant bisphenol A in canned, glass and polyethylene terephthalate plastic carbonated beverages of diverse flavors and origin
Abstract Bisphenol A (BPA) is a hazardous contaminant demonstrating endocrine disrupting properties, and assumed to be involved in the pathogenesis of various cancer diseases for instance prostate, lung and breast cancer. The objective of the present study was to estimate the BPA amounts in carbonated beverages from the Saudi Arabian market for the first tim
Food Sci. Technol. Publicado em: 2021-03
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10. Productivity and photosynthetic pigments in bell pepper plants grown in soil with biofertilizer and protected against water loss
ABSTRACT The search for techniques that maximize the use of water is becoming necessary for the sustainability of agriculture in semi-arid areas. In this sense, the present work aimed to evaluate the effects of soil protection against water loss and the use of bovine biofertilizer on fruit production and chlorophyll content in bell pepper plants. The experim
Rev. Ceres. Publicado em: 2021-02
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11. Development of a Methodology Based on Extraction Induced by Emulsion Breaking for Copper Determination in Gasohol by Graphite Furnace Atomic Absorption Spectrometry
The development of a method based on extraction induced by emulsion breaking (EIEB) aiming copper determination in gasohol using graphite furnace atomic absorption spectrometry (GF AAS) is reported. Emulsification of the gasohol samples was carried out using nitric acid solution, (1,1,3,3-tetramethylbutyl)phenyl-polyethylene glycol surfactant (Triton X-114),
J. Braz. Chem. Soc.. Publicado em: 2021-02
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12. Isotopic Analysis of Sugarcane/Petroleum Polyethylene Blends: A Perspective on the Application of Stable Isotope Method (δ13C)
In the present work, we propose the application of stable isotope analysis (δ13C) as an auxiliary tool for the inspection of sugarcane/petroleum polyethylene blends. Our results are supported from the analysis of selected samples by accelerator mass spectrometry (14C-AMS). From the results, it was concluded that the δ13C method is suitable to discriminate
J. Braz. Chem. Soc.. Publicado em: 2021-01