16 research outputs found
Degradação e estabilização do diclofenaco em nanocåpsulas poliméricas
I den tidigare gjorda kunskapsöversikten fann vi âhĂ„lâ i forskningen gĂ€llande elevers upplevelser om kooperativt lĂ€rande. Denna studie undersöker dĂ€rför elevers upplevelser och erfarenheter om kamratrespons i matematikĂ€mnet. Lundgren, SĂ€ljö och Liberg (2014, s.308) menar pĂ„ att kunskap Ă€r nĂ„gonting som vĂ€xer fram i interaktion mellan elever. LĂ€randet ses alltsĂ„ som en del av den mĂ€nskliga gemenskapen dĂ€r skolans uppgift Ă€r att involvera mĂ€nniskor i samhĂ€llets kollektiva kunskaper. Fohlin et al. (2017 s.13) menar i sin tur pĂ„ att det samhĂ€llet vi lever i idag Ă€r demokratiskt och förvĂ€ntas dĂ€rför ha sammanlĂ€nkande roller. Varför speglas dĂ„ inte undervisningen av ett hjĂ€lpande beteende. LĂ€roplanen för grundskolan, förskoleklassen och fritidshemmet 2011 (Lgr11, s. 9) slĂ„r fast att skolan ska strĂ€va efter att vara en levande och social gemenskap som ska bidra till vilja, trygghet samt lust att lĂ€ra. Den ska Ă€ven strĂ€va efter att skapa de ultimata förutsĂ€ttningarna för elevernas kunskapsutveckling, bildning och tĂ€nkande. Varje enskild elev i skolan har rĂ€tt att fĂ„ utvecklas, fĂ„ en ökad glĂ€dje, fĂ„ möjlighet till att uppleva tillfredsstĂ€llelse som ges vid framsteg och klara av de svĂ„righeter som kan uppstĂ„. Syftet med studien Ă€r dĂ€rför att undersöka yngre elevers upplevelser och erfarenheter av arbetssĂ€ttet kamratrespons inom matematikĂ€mnet. Vilka Ă€r elevernas upplevelser om kamratrespons och hur arbetar eleverna med kamratrespons och varför gör de det? För att finna svar pĂ„ studiens syfte och frĂ„gestĂ€llningar har en kvalitativ metod anvĂ€nts, genom fokusgruppsdiskussioner. Resultatet i studien indikerar i huvudsak pĂ„ att eleverna har en positiv instĂ€llning och upplevelse till arbetssĂ€ttet kamratrespons. Det framgĂ„r Ă€ven att eleverna inte endast trĂ€nar Ă€mnesinnehĂ„ll utan Ă€ven sociala förmĂ„gor dĂ„ lĂ€randet sker i en social kontext. Resultatet visar att kamratrespons har positiv inverkan pĂ„ elevers kunskapsutveckling, uthĂ„llighet och motivation. Men förmĂ„gan att ge varandra gynnsam respons krĂ€ver övning dĂ€r elevernas ansvarskĂ€nsla behöver utvecklas, bĂ„de för sitt eget men ocksĂ„ för gruppens lĂ€rande. För att kunna genomföra kamratrespons pĂ„ korrekt sĂ€tt krĂ€vs det prioritering frĂ„n lĂ€raren under en lĂ€ngre period. LĂ€raren behöver ocksĂ„ ha en förstĂ„else för att arbetssĂ€ttet inte passar alla elever. Men dĂ„ forskningen belyser goda effekter nĂ€r det gĂ€ller kooperativt lĂ€rande fĂ„r lĂ€raren stöd i sitt didaktiska beslut att arbeta med kamratrespons
InfluĂȘncia do sistema de produção e do armazenamento refrigerado nas caracterĂsticas fĂsico-quĂmicas e no desenvolvimento de compostos volĂĄteis em morangos
Digestibilidade determinada pelo método indireto usando o n-alcano C35 Digestibility determinate by indirect method using C35 n-alkane
Foi feito um trabalho de extração e anĂĄlise de n-alcanos com o objetivo de investigar o uso do n-alcano (C35) presente nas forragens como um indicador interno para determinação de digestibilidade. Foram utilizadas amostras de experimentos de digestibilidade convencional realizados previamente entre os anos de 1978 e 1982. O C35 subestimou as digestibilidades da matĂ©ria seca e orgĂąnica, apresentando diferença mĂ©dia, em relação ao mĂ©todo in vivo, de 4,68 (± 0,69) e 4,43 (± 0,85) unidades percentuais, respectivamente. O coeficiente de regressĂŁo nĂŁo diferiu da unidade, indicando que os mĂ©todos foram equivalentes, havendo, porĂ©m, a necessidade de um fator de correção. Os coeficientes de correlação para a matĂ©ria seca e orgĂąnica, observados entre os dois mĂ©todos, foram 0,87 e 0,85, respectivamente. O C35 apresentou recuperação fecal mĂ©dia de 91,76% (± 7,94), que contribuiu para o vĂcio da tĂ©cnica.<br>An experiment was conducted, on extraction and analysis of n-alkanes, to investigate the use of n-alkane (C35) present in forages as an internal marker for the digestibility determination. Samples of forages and feces were taken from conventional digestibility trials, which were previous conducted from 1978 to 1982. The C35 underestimated the dry matter and organic matter digestibilities, presenting an average difference in relation to in vivo of 4.68 (± 0.69) and 4,43 (± 0.85) perceptual units, respectively. The coefficient of regression did not differ from the unit, indicating that both methods were equivalent, having, however, the necessity of a correction factor. The coefficients of correlation observed for the dry and organic matter between the two methods were 0.87 and 0.85, respectively. The average fecal recovery of C35 was 91.76% (± 7.94), and this contributed to the bias of the method
Optimization of ethyl ester production from olive and palm oils using mixtures of immobilized lipases
Although reactions of transesterification are generally catalyzed by one specific lipase preparation, the concept of âcombi-lipaseâ could be better explored for the production of biodiesel, since oils are heterogeneous substrates. In this research, we tested this concept by evaluating the enzymatic transesterification of olive and palm oils, two diverse fatty acid compositions, using standalone or mixtures of three immobilized lipases as biocatalysts: Novozym 435 (CALB), Lipozyme TL-IM (TLL), and Lipozyme RM-IM (RML). For olive oil, the combination of 29.0% of TLL, 12.5% of RML, and 58.5% of CALB was the best, allowing for 95% conversion efficiency in 18 h of reaction, up from 50% for the best individual lipase (CALB). For palm oil, the best enzyme combination was 52.5% of TLL and 47.5% of RML, resulting in 80% of conversion of ethyl esters in 18 h, compared to only 44% when standalone TLL was used. Repeated batches of reaction were carried out in order to test the operational stability of the combi-lipase systems, with results showing that they could be used for at least seven cycles keeping higher than 80% of their initial activities.This work was supported by grants from Brazilian Coordenação de Aperfoiçoamento de Pessoal de NĂvel Superior (CAPES) and CTQ2013-41507-R from Spanish MINECO.Peer Reviewe
Degradação e estabilização do diclofenaco em nanocåpsulas poliméricas
The parameters which affect the degradation and stabilization of diclofenac in suspensions of nanocapsules and of the corresponding spray-dried powders were investigated. Formulations were subjected to 14 months of storage at room temperature. In addition, a study of the degradation of diclofenac was carried out by exposing the formulations or mixtures (drug and adjuvants) to UVC wavelengths. The presence of Epikuron 170Âź in a concentration higher than 3.06 mg/mL stabilizes the drug, avoiding its reduction or degradation. The degradation products were isolated, analyzed by gas chromatography-mass spectrometry, and identified as 2-(2',6'-dichlorophenyl)aminobenzyl alcohol and N-(2',6'-dichlorophenyl)anthranilylaldehyde