1,879 research outputs found
A Comparative Study of Physicochemical, Dielectric and Thermal Properties of Pressboard Insulation Impregnated with Natural Ester and Mineral Oil
Get PDFNatural ester is considered to be a substitute of mineral oil in the future. To apply natural ester in large transformers safely, natural ester impregnated solid insulation should be proved to have comparable dielectric strength and thermal stability to mineral oil impregnated solid insulation. This paper mainly focuses on a comparative study of physicochemical, ac breakdown strength and thermal stability behavior of BIOTEMP natural ester/pressboard insulation and Karamay 25# naphthenic mineral oil/pressboard insulation after long term thermal ageing. The physicochemical and dielectric parameters including moisture, acids and the ac breakdown strength of these two oil/pressboard insulation systems at different ageing status were compared. The permittivity and ac breakdown strength of these two oil/pressboard insulation systems at different temperatures were also investigated. And a comparative result of the thermal stability behavior of these two oil/pressboard insulation systems with different ageing status was provided at last. Results show that though natural ester has higher absolute humidity and acidity during the long ageing period, the lower relative humidity of natural ester helps to keep its ac breakdown strength higher than mineral oil. The pressboard aged in natural ester also has higher ac breakdown strength than that aged in mineral oil. The lower relative permittivity ratio of natural ester impregnated paper to natural ester is beneficial to its dielectric strength. Using natural ester in transformer, the resistance to thermal decomposition of the oil/pressboard insulation system could be also effectively improved
<i>No se sabe</i>: entrevista a Nilda Ester Radman
No full textEntrevista a la médica veterinaria y bacterióloga clínica industrial Nilda Ester Radman, profesora titular de Parasitología Comparada en la Facultad de Ciencias Veterinarias de nuestra universidad y estudiosa de las enfermedades zoonóticas.Al hacer clic en el enlace que figura en "Documentos relacionados", pueden accederse a todos los trabajos de Nilda Ester Radman presentes en el repositorio.Radio Universidad Nacional de La Plat
Quantitative Analysis Ageing Status of Natural Ester-paper Insulation and Mineral Oil-paper Insulation by Polarization/Depolarization Current
No full textPolarization and Depolarization Current (PDC) technique is an effective tool to assess the condition of oil-paper insulation system in power transformers. So far the PDC behaviors of mineral oil-paper insulation have been widely investigated. However, with the increasing number of transformer choosing natural ester as its insulation oil, it is important to investigate the PDC characteristics of natural ester-paper insulation to see whether the PDC technique can also be used to assess the condition of new insulation system using natural ester in transformers accurately. In this research, natural esterpaper insulation sample and mineral oil-paper insulation sample were subjected to thermally accelerated ageing experiment at 110 °C for 120 days. The PDC characteristics of natural ester-paper insulation sample and mineral oil-paper insulation sample were compared over the ageing process. A new method for assessing the ageing condition of the oil-paper insulation in terms of the depolarization charge quantity was proposed. Results show that the polarization/depolarization current of natural ester-paper insulation sample is higher than that of mineral oil-paper insulation sample with the same ageing intervals. The depolarization charge quantity of both kinds of oil-paper insulation sample is very sensitive to their ageing conditions. There is an exponential relation between the stable depolarization charge quantity of both kinds of oil-paper insulation sample and the degree of polymerization (DP) of paper. The depolarization charge quantity can be used to predict the ageing condition of oil-paper insulation providing the measurement temperature is kept the same
Ester Formation
No full textThe present invention is in the field of a process for producing an ester, such as a biobased ester, from an aqueous biomass comprising solution, batch wise or continuously, wherein use of raw material is limited and if possible re-used. The present invention is in the field of green technology.BT/BiotechnologyApplied Science
Unsex me here. Ambivalenza e metamorfosi di Lady Macbeth
No full textMacbeth is the tragedy of desire. Lady Macbeth’s identity is a fiction of closure, namely a metonymic part that cannot represent the whole, the predetermined complexity with which being coincides with its subjectuality, made even more evident by the non-allocation of a name from the author. Being of Lady Macbeth is an aporia that says the true, because it built on an identification of opposites and destined inevitably to death to get a resolution of the internal conflict that embodies
Uso da Papaína, Calendula officinalis e Própolis no processo de cicatrização de lesões cutâneas
Get PDFArtigo apresentado ao curso de graduação em Farmácia da UniCesumar – Centro Universitário de Maringá como requisito parcial para a obtenção do título de bacharel (a) em Farmácia, sob a orientação do Prof. Dr. Bruna Muller Cardoso e Co-orientadores Sônia Maria de Matos Pereira Silveira e Suzana Ester Nascimento Ogava.Este estudo tem por objetivo avaliar a evolução terapêutica dos géis de Papaína, Própolis e Calêndula em casos de lesões cutâneas e verificar a efetividade desses produtos no processo de cicatrização dessas feridas, assim como contribuir para a ampliação do uso de fitoterápicos em Maringá. Os dados foram obtidos através do acompanhamento de 11 pacientes no Ambulatório de Feridas do Hospital Municipal de Maringá Drª Thelma Villanova Kasprowicz, sendo observado os curativos realizados, registro de avaliação e medidas, evolução e mudanças fisiológicas e características das lesões. Para avaliar a cicatrização, foi realizado a mensuração da lesão no início e ao término do tratamento e ainda foram realizados registros fotográficos para comprovação da efetividade dos géis. Por meio de análise estatística através do cálculo do coeficiente de correlação de Pearson foi possível determinar a evolução cicatricial das lesões. Durante os três meses de acompanhamento das feridas 33,0% apresentaram completa cicatrização e em 56,0% dos casos obteve-se redução da lesão com contração das bordas. Em 6,0%, houve redução do processo inflamatório e cicatrização parcial, no entanto o paciente foi encaminhado para procedimento cirúrgico. E apenas 5,0% dos pacientes desistiram do tratamento após melhora do quadro clínico. Com relação a atuação terapêutica da Papaína, Própolis e Calêndula, o estudo demonstrou resultados satisfatórios com evolução de todos os quadros clínicos. O uso dos géis reduziu o tempo de cicatrização, acelerou a regeneração do tecido e proporcionou reepitelização total em 33,0% das lesões durante apenas três semanas de tratamento, confirmando assim a eficácia dos produtos
Apertura del fallimento e rapporti di lavoro
No full textA partire dall’apertura della procedura liquidatoria, i lavoratori sono sospesi senza retribuzione
e senza diritto di percepire misure di sostegno al reddito, a meno che non vi siano
rapide prospettive di cessione dell’azienda o di suoi rami. Per un certo periodo di tempo, inoltre,
ai prestatori è precluso dimettersi per giusta causa. Dopo essersi soffermati sulla natura e
sul fondamento giuridico della sospensione dei rapporti, regolata nell’art. 72 l.f. e, a partire dal
1° settembre 2021, nell’art. 189, d.lgs. n. 14/2019, ci si interroga sulla legittimità costituzionale
di tali norme che paiono arrecare un vulnus all’art. 4 Cost. e 38 Cost. per la combinazione fra
sospensione non retribuita del rapporto di lavoro e divieto di dimissioni “in tronco”.Starting from the opening of the liquidation procedure, employees are suspended without pay and without the right to receive income support measures, unless there are rapid prospects for the sale of the company. Furthermore, for a certain period of time, employees are not allowed to resign for just cause. After linging on the nature and the legal basis of the suspension of the contractual relation, the Author investigates the constitutional legitimacy of these rules which seem to cause a violation of art. 4 and art. 38 of the Constitution for the combination of unpaid suspension of the employment relationship and prohibition of immediate resignation
Black European Inscriptions and the Challenge to Modern Essentialist Identities: The Case of Bernardine Evaristo’s Soul Tourists
No full textThis essay shows how the London-born Anglo-Nigerian author Bernardine Evaristo contributes, with her Soul Tourists (2005), to deconstructing modern European nationalist and racially exclusivist models by means of anti-essentialist representational strategies. Centred around the voyage by car and across Europe which, in the late eighties, leads two black Britons, Stanley Williams and Jessie O’Donnell, from England to the Middle East, the novel becomes an imaginative vehicle through which Evaristo represents the black presence as intrinsic to Europe since the th century and foregrounds the substantial contribution of black and mixed-race men and women to the cultural development of Western civilisation
Nella biblioteca di Hartmann Schedel: l'index librorum aldino del 1498 e le Decades rerum Venetarum di Marcantonio Sabellico
No full textThe contribution examines the first catalogue issued by Aldo Manuzio on 1 October 1498 and in particular the copy in the Österreichische Nationalbibliothek in Vienna (Ink. 7.A.13). A careful examination of the manuscript annotations, known to be by Hartmann Schedel, has enabled the author to identify the volume in which Schedel had the catalogue bound in his lifetime: a copy of Marcantonio Sabellico’s Decades rerum Venetarum (Venice, Andrea Torresani, 1487) also in the Österreichische Nationalbibliothek (Ink. 7.A.7). A detailed description of the item and Schedel's textual and graphic additions reveals for the first time what was one of the most significant books in the humanist's library and allow us to reconstruct the overall context of its use in the years immediately following its publication
Thermo analitycal study of ethoxylated sorbitan ester
No full textO éster de sorbitan etoxilado (ESE) é obtido por meio de duas reações consecutivas. Na primeira reação, ácidos graxos são esterificados com sorbitol, gerando os ésteres de sorbitan, podendo ser utilizados nesta reação diferentes tipos de ácidos graxos, de diversas origens, produzindo ésteres com diferentes características. Em seguida, estes ésteres são modificados pela adição de óxido de eteno, obtendo-se então os ésteres de sorbitan etoxilados. Esses ésteres constituem um grupo de tensoativos não-iônicos com ampla aplicação em cosméticos, detergentes, produtos farmacêuticos, formulações agroquímicas e alimentos. Para determinadas aplicações, o produto líquido é convertido para a forma sólida a partir da adsorção em composto mineral. Este trabalho teve como objetivo estudar o comportamento térmico do produto sólido, empregando-se as técnicas termoanalíticas. Os ensaios TG e DSC mostraram que o composto mineral catalisa a decomposição térmica do produto diminuindo seu tempo de vida útil. Os espectros no infravermelho dos voláteis liberados durante o processo térmico indicaram a formação de aldeídos e/ou ácidos carboxílicos como produtos da oxidação. Alguns antioxidantes foram testados e o BHA apresentou melhor desempenho. Observou-se que, mesmo com a adição de antioxidantes, o processo de auto-aquecimento do ESE em composto mineral não é inibido totalmente e isso torna recomendável estocar o material em local apropriado e em embalagens pequenas. Também se sugere embalar o produto sob pressão reduzida ou empregando atmosfera inerte, por exemplo, nitrogênioThe ethoxylated sorbitan ester is produced by two consecutive reactions. In the first reaction, fatty acids are esterified with sorbitol producing sorbitan esters; different types of fatty acids from various sources can be used, producing ester with different characteristics. Afterwards these esters are modified by the addition of ethylene oxide, resulting in the ethoxylated sorbitan esters. These esters are a group of nonionic surfactants with wide application in cosmetics, detergents, pharmaceuticals, agrochemical formulations and food. For certain applications the liquid product is converted into the solid state by adsorption in mineral compound. This study aimed to evaluate the thermal behavior of the product in the solid form using the thermalanalytical techniques. TG and DSC experiments have demonstrated that the mineral compound catalyzes the thermal decomposition of the product, reducing its shelf life. The infrared spectra of the volatile released during the thermal process indicated the formation of aldehydes and/or carboxylic acids as oxidation products. Some antioxidants were tested and BHA showed the best performance. It was observed, however, that even with the addition of antioxidants the process of self-heating of ESE in mineral compound is not completely inhibited and this makes it advisable to store the material in an appropriate area and in smaller packages. It also suggests packing the product under reduced pressure or using inert atmosphere as nitrogen, for example
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