Juliana Kloss - Academia.edu (original) (raw)

Papers by Juliana Kloss

DELOS: DESARROLLO LOCAL SOSTENIBLE

Aproximadamente 23 milhões de pessoas praticam surfe em todo o mundo, das quais cerca de 3 milhõe... more Aproximadamente 23 milhões de pessoas praticam surfe em todo o mundo, das quais cerca de 3 milhões são brasileiros, segundo levantamento feito pela International Surfing Association (ISA). O principal equipamento necessário para a prática desse esporte é a prancha de surfe, que em geral é produzida com espuma de poliuretano rígido expandido (PUR), revestida com resina de poliéster, fibra de vidro e outras substâncias químicas. Neste trabalho, foi verificado a possibilidade de incorporar os resíduos de PUR em formulações de concreto visando a produção de blocos de vedação para aplicação na construção civil. O resíduo foi caracterizado através das análises de resistência à compressão, resiliência, densidade, dureza e espectroscopia na região do infravermelho com transformada de Fourier. Para avaliação das formulações e propriedades, corpos cilíndricos de concreto foram confeccionados de acordo com a norma ABNT NBR 12821:2009, incorporando na formulação PUR triturado, granulometria si...

Revista Ibero-Americana de Ciências Ambientais, 2021

A crescente utilização de materiais poliméricos descartáveis, contrapondo o tempo longo de decomp... more A crescente utilização de materiais poliméricos descartáveis, contrapondo o tempo longo de decomposição, torna necessário pensar em propostas para minimizar o impacto ambiental decorrente do descarte inadequado na natureza. Dessa forma, uma das alternativas é a reciclagem mecânica, possibilitando o resíduo ter viabilidade comercial. Nessa perspectiva o presente trabalho teve como objetivo construir luminárias de poliestireno (PS) reciclado mecanicamente a partir de copos descartáveis. Os copos foram recolhidos quinzenalmente durante seis meses, submetidos à triagem e secagem. Em seguida, triturados, processados via extrusão, granulados e processados via injeção. Os materiais foram analisados através das seguintes técnicas: espectroscopia na região do infravermelho, ensaio mecânico de tração, teste de chama, teste de ausência de cloro (teste de Beilstein) e teste prévio de amarelamento. Foram comparados o PS cristal virgem e o PS reciclado. Após a caracterização, os cor...

Journal of the Brazilian Society of Mechanical Sciences and Engineering, 2021

Developing new materials for additive manufacturing (AM) technologies is an important topic, usua... more Developing new materials for additive manufacturing (AM) technologies is an important topic, usually targeting cost reduction or better physical properties, or both. This research aims to evaluate the mechanical properties and thermal stability of a non-commercial basic photosensitive acrylic material by the addition of organophilic clays. The organophilic clays Cloisite 20 ® and organophilic bentonite clay modified with cetyltrimethyl ammonium bromide (BN-CT) were dispersed-0.5, 1.0 and 1.5 (wt%)-in the monomer trimethylolpropane triacrylate, using two dispersion methods. The samples were obtained by the AM principle, similar to the vat photopolymerization technology, in which the deposition and curing were performed layer by layer with Ultraviolet-C radiation. The formulations were checked for viscosity, shrinkage, warping, and strength (tensile and bending test), and analyzed using a scanning electron microscope (SEM), an energy dispersive X-ray spectrometer (EDS), X-ray diffraction (XRD), and thermogravimetry (TGA). The characterization of the formulations obtained from the two organophilic clays, Cloisite 20 ® and BN-CT, by the two methods of dispersion, in principle, indicated the formation of a material with an intercalated hybrid morphology structure. The formulations showed improvements in tensile strength (15% for Cloisite 20 ® and 18% for BN-CT) and flexural strength (14% for Cloisite 20 ® and 10% BN-CT). The formations´ thermal stability (degradation) was not affected by the addition of the clays; therefore, the cheaper BN-CT would be preferred to improve their mechanical properties.

Os poliuretanos (PU’s) foram desenvolvidos por Otto Bayer em 1937 e sao produtos de uma reacao en... more Os poliuretanos (PU’s) foram desenvolvidos por Otto Bayer em 1937 e sao produtos de uma reacao entre um isocianato e um poliol. No meio reacional podem ser adicionados tambem catalisadores, aditivos, corantes, cargas, entre outros, para melhorar as caracteristicas e propriedades do produto final. A natureza dos reagentes e a composicao da formulacao oferece uma grande flexibilidade a esta classe de polimero, fato que a torna importante no mercado mundial. Dentre os tipos de poliuretanos encontram-se as espumas, que podem ser rigidas, semi-rigidas ou flexiveis. As espumas possuem grande aplicabilidade no mercado de colchoes, estofados, protetores de equipamentos eletronicos, isolamento acustico e termico. Porem, o descarte e acumulo desses produtos constituem um problema ambiental crescente. Desta forma, o presente estudo propoe uma revisao bibliografica sobre o desenvolvimento, testes e os beneficios que as espumas (rigidas e flexiveis) biodegradaveis vem trazendo para o cenario amb...

EnglishIn the process of manufacture of tire treads, carbon black is incorporated in formulation ... more EnglishIn the process of manufacture of tire treads, carbon black is incorporated in formulation for improved rolling resistance property of the tire. However, some alternative additives, such as bentonite clays, are partially being added in the formulations to reduce the amount of heat accumulated in the tire, increasing durability, reducing manufacturing cost and therefore the value of the final product. In this work, part of the carbon black used in the preparation of formulations of tread, by bentonite clay, an alternative and renewable source coming from load was replaced. For this study, five formulations were developed, one conventional and four replacing 5.00 or 10.00 PHR of carbon black by bentonites Vulgel CN 45 or Cloisite® Na+. Rheometry analysis, hardness, density and abrasion resistance were made in all compositions. The addition of 5.0 PHR alternative load, was enough to maintain the original properties of the compound, reaching 10.0 PHR without significant changes. I...

Chinese Traditional Patent Medicine, 2004

AIM:To make a evaluation of high-dose Senmai(Radix Ginseng Rubra, Radix Ophiopogonis, Fructus sch... more AIM:To make a evaluation of high-dose Senmai(Radix Ginseng Rubra, Radix Ophiopogonis, Fructus schisandrae.)(HD-SM)in treating patients with advanced cancer.METHODS:32 patients with advanced cancer were assigned to treatment group. And 28 cases were assigned to the control group. The treatment group received chemotherapy and HD-SM, the control group received chemotherapy and the routine supporting treatment (except HD-SM). The toxicity and effect of all patients were observed, and the value of HD-SM was assessed.RESULTS:All cases in treatment group received 4 chemotherapy courses according to plan. The toxicities were tolerable, and the effect was satisfactory. All cases in the control group were only performed 1 course of treatmeur.CONCLUSION:HD-SM can decrease the effect of chemotherapy and reduce chemotherapeutic toxicities, and it is a very effective supporting treatment in chemotherapy.

L'invention concerne l'utilisation d'une argile nanostructuree organophile exempte de... more L'invention concerne l'utilisation d'une argile nanostructuree organophile exempte de sel d'ammonium dans du polyethylene, consistant en la preparation d'un nanocomposite au moyen de la technique d'intercalation du polymere fondu, par trois modes de traitement distincts, faisant intervenir un polymere appartenant a la famille des polyolefines, de preference un polyethylene (basse densite, haute densite, basse densite lineaire) et une argile naturelle appartenant a la famille des phyllosilicates, de preference du groupe 2:1, modifiee avec un agent tensioactif derive de l'acide carboxylique. Le compose recommande pour cette invention est le stearate de sodium, CH 3 (CH 2 ) 16 COO - Na + ou o lauril sulfato de sodio, CH 3 (CH 2 ) 11 SO 4 "Na + (methodologie en phase d'obtention de brevet - DEPR 015100000646), soit un agent tensioactif different du sel d'ammonium.

Journal of Perinatology, 2021

We compared neonatal immunity after vaccination against SARS-CoV-2 during pregnancy to that achie... more We compared neonatal immunity after vaccination against SARS-CoV-2 during pregnancy to that achieved after maternal infection. STUDY DESIGN: We tested cord blood from women infected with SARS-CoV-2 during pregnancy (group 1, n = 29), women who were vaccinated during pregnancy (group 2, n = 29) and from women not infected and not vaccinated (Group 3, n = 21) for titers of antibodies to both SARS-CoV-2 spike and 'N' proteins. RESULTS: Seventy-nine women were included: Antibodies against SARS-CoV-2 spike protein were detected in all samples from Group 1 and 2. Antibodies to the 'N' protein were detected in 25/29 samples in Group 1. None of the samples from Group 3 had antibodies to either protein. Mean titers of SARS-CoV-2 antibodies were significantly higher in Group 2 than in Group 1 (p < 0.05). CONCLUSIONS: Neonates born to mothers vaccinated during pregnancy have higher antibody titers and may therefore have more prolonged protection than those born to women infected during pregnancy.

Polímeros, 2020

EVA systems, using an environmentally friendly organoclay modified with a non-ionic and free of a... more EVA systems, using an environmentally friendly organoclay modified with a non-ionic and free of ammonium ions modifier (BN-AM), were prepared in a single-screw laboratory extruder and characterized by rheological, morphological and thermal properties. WAXD analysis suggested that the nanocomposites with 1.5 wt% of BN-AM presented an exfoliated structure, while the rheological results showed that the nanocomposites with BN-AM organoclay tended to present a more pronounced shear thinning behavior when compared to EVA and the nanocomposites with the traditional organoclay. The SEM/EDS analysis by using elemental mappings showed good dispersion of the organoclays (BN-AM and BN-CT) in the EVA matrix. Thermogravimetry analysis showed an improvement in thermal stability of EVA when the non-ionic modifier was used instead of the traditional one. In general, it was concluded that the addition of low content of BN-AM organoclay in EVA matrices is a promising option for the production of nanocomposites.

Journal of Photochemistry and Photobiology A: Chemistry, 2019

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Abstracts, 2019

Conclusions Although recommendations are being followed, there is still place for antibiotic ther... more Conclusions Although recommendations are being followed, there is still place for antibiotic therapy in RSV infection. The need for antibiotic cannot be easily predicted upon traditionally used inflammatory markers. Due to prolonged hospital stay, there is strong need for minimizing antibiotic use, and more precise clinical tools to assess the risk of antibiotic.

Agradeço sinceramente a todos que, com boa intenção, colaboraram para a realização e finalização ... more Agradeço sinceramente a todos que, com boa intenção, colaboraram para a realização e finalização deste trabalho. Agradeço de maneira muito especial, à Profa. Dra. Sônia Faria Zawadzki, pela orientação em todas as etapas da minha vida acadêmica, pelos ensinamentos e confiança ao longo dos anos.

Revista Virtual de Química, 2015

Macromolecular Symposia, 2012

Disposal of petroleum-derived polymers is a growing global environmental problem of alarming prop... more Disposal of petroleum-derived polymers is a growing global environmental problem of alarming proportions, which has increased interest in the use and production of biodegradable materials. In addition to biodegradation, investment in research and development in the nanotechnology area is also significant. This study evaluated the effect of incorporation of an organophilic nanoclay ammonium-free salt (Novaclay TM) on the mechanical properties and biodegradation of a biodegradable polyester (Ecoflex 1), according to ASTM G 160. Ecoflex with and without incorporated Novaclay was characterized before and after biodegradation in organically enriched soil for up to 180 days, by visual analysis, optical microscopy, weight loss, differential scanning calorimetry, dynamic mechanical analysis, mechanical testing, and scanning electron microscopy. The pure Ecoflex and the Ecoflex/Novaclay nanocomposite were partially biodegraded by the method used, and showed changes in their morphological and mechanical properties.

Macromolecular Symposia, 2003

Macromolecular Symposia, 2011

Bentonite is a technical term applied to layered silicates of very thin granulation, mainly compo... more Bentonite is a technical term applied to layered silicates of very thin granulation, mainly composed by minerals of the smectites group. Montmorillonite, a phylossilicate with layers as thick as 1 nm, is the most common structure in the bentonite clay. The polarity of these materials is incompatible with most of the usual polymers and in order to overcome this problem, chemical modifications are often necessary. The purpose of this work is to evaluate the chemical and physical characteristics of different bentonites by comparing their product data sheets, their performance in the water Foster swelling and their response to chemical modifications of their surfaces structures. The samples were characterized by infrared spectroscopy and X-ray diffraction analysis. All bentonite samples showed effective intercalations of the modifying agent on their surface structures. This behavior showed the possibility of usage of these materials in the polymer layered silicates nanocomposites preparations.

Journal of Polymer Science Part A: Polymer Chemistry, 2002

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Journal of Applied Polymer Science, 2007