Energy efficiency in power transformers

The objective of this report is to calculate the amount of incentives in order to achieve the potential energy saving of distribution transformer in distribution network. Firstly, a case study for Spain with the basic data of the power installed of three different energy efficiency rates of transformers has been created. Then the problem formulation in GAMS is presented with the objective function to maximize the benefit in year n to fulfill with the demand growth, under the control of the economic constraint RD222/2008 and the improvement overall efficiency constraint. As a result, the objective of this project can be achieved

Microencapsulação da curcumina em partículas lipídicas sólidas visando aplicações alimentares sujeitas a processamento térmico

Mestrado de dupla diplomação com a UTFPR - Universidade Tecnológica Federal do ParanáA utilização de corantes naturais é uma tendência de marketing atual, pois possuem benefícios para a saúde e o seu uso vai ao encontro das preocupações dos consumidores com a segurança dos corantes artificiais. Porém, a sua utilização eficiente apresenta vários desafios. A curcumina é um corante natural que, além de conferir cor, possui diversas atividades biológicas, servindo de alternativa a alguns corantes artificiais. Tal como grande parte dos corantes naturais, apresenta sensibilidade a tratamentos térmicos, o que limita a sua aplicação em produtos alimentares submetidos ao cozimento em fornos, como por exemplo, os produtos de pastelaria/panificação, sendo a encapsulação uma alternativa que pode ser utilizada para superar este problema. Neste contexto, o trabalho teve como objetivo encapsular a curcumina em matrizes lipídicas sólidas, viabilizando a sua estabilidade térmica para posterior aplicação em produtos de pastelaria/panificação, garantindo a manutenção da cor. A composição do material encapsulante foi definida por um planeamento experimental simplex-centroid. A técnica utilizada para a produção das partículas foi o Spray Congealing, tendo sido produzidas três formulações compostas por cera de abelha, cera de carnaúba e miglyol 812 em diferentes proporções. Estudos de caracterização foram realizados mostrando que a curcumina foi eficientemente encapsulada e análises de microscopia ótica mostraram que as micropartículas produzidas apresentaram formato esférico com tamanhos na faixa de micrômetros (0,19-139 μm). A estabilidade térmica das partículas foi avaliada por Calorimetria de Varrimento Diferencial (DSC), as interações entre o material encapsulante e o principio ativo foram analisadas por Espectroscopia de Infravermelho com Transformada de Fourier (FTIR) e um delineamento Box-Behenken foi realizado permitindo descrever a variação da cor com a temperatura, o tempo de aquecimento e a composição do material encapsulante. Os resultados do planeamento foram também submetidos a uma análise de componentes principais (PCA), tendo as micropartículas encapsuladas com cera de abelha pura e com a mistura cera de abelha, carnaúba e miglyol as que conduziram a uma menor variação de cor. Por fim as micropartículas foram adicionadas a matrizes alimentares com diferente carácter hidrofílico/lipofílico, sendo elas, queijo fundido, nata de culinária, manteiga, leite condensado, margarina vegetal líquida, iogurte natural com 0% de matéria gorda, iogurte natural, iogurte natural batido (tipo Grego) e maionese, tendo-se avaliado o seu comportamento quanto à estabilidade da cor durante o armazenamento por 7 dias, tendo o teor de humidade influência direta na homogeneidade do ingrediente corante com a matriz alimentar.The use of natural colorants is a current marketing trend; they have health benefits and their use meets consumer’s concerns with the safety of artificial counterparts. However, their efficient use presents several challenges. Curcumin is a natural colorant that, in addition to conferring color, has several biological activities, serving as an alternative to some artificial colorants. Like most natural colorants, it is sensitive to heat treatments, which limits its application in foodstuffs submitted to cooking in ovens, as is the case of pastry/bakery products, being encapsulation an alternative that can be used to overcome this problem. In this context, the objective of the present work was to encapsulate curcumin in solid lipid matrices, increasing thermal stability for subsequent application in pastry/bakery products, ensuring color maintenance. The composition of the encapsulating material was defined by a simplex-centroid experimental design. The technique used for the production of the particles was Spray Congealing, and three formulations comprising beeswax, carnauba wax and miglyol 812 in different proportions were produced. Characterization studies were performed showing that curcumin was efficiently encapsulated and optical microscopy analyzes showed that the produced microparticles had a spherical shape with sizes in the micrometer range (0,19-139 μm). The thermal stability of the particles was evaluated by Differential Scanning Calorimetry (DSC), the interactions between the encapsulating material and the active principle were analyzed by Fourier Transform Infrared Spectroscopy (FTIR), and a Box-Behnken design was performed allowing to describe the color variation with temperature, heating time and the composition of the encapsulating material. The results of the planning were also submitted to a principal component analysis (PCA) showing that the microparticles encapsulated with pure beeswax and the mixture of beeswax, carnauba and miglyol were the ones conducting to the lowest color variation. Finally, the microparticles were added into food matrices with different hydrophilic/lipophilic character, such as melted cheese, cooking cream, butter, condensed milk, liquid vegetable margarine, natural yogurt with 0% fat, natural yogurt, natural yogurt whipped (Greek type) and mayonnaise, and color stability was evaluated during a storage period of 7 days, having the moisture content a direct influence on the color homogeneity of the food matrix.Este trabalho é financiado pelo Fundo Europeu de Desenvolvimento Regional (FEDER) através do Programa Operacional Regional Norte 2020, no âmbito do Projeto Norte-01-0247-FEDER-024479 (projeto Mobilizador ValorNatural®)

Surgical Punctal Occlusion; Combined Lacrimal Canaliculi Cauterization and Punctal Suturing for Severe Dry Eye

Purpose: To evaluate the treatment outcome of surgical punctal occlusion with combined canaliculi ablation and punctal suturing in patients with severe dry eye. Methods: Eleven eyes of seven patients were diagnosed with severe dry eye with decreased lacrimal secretion and were refractory to treatment with various eye drops and/or had repeatedly experienced loss of punctal plugs, and continued to experience subjective symptoms received surgical punctal occlusion. In 20 puncta, lacrimal canaliculi ablation was performed along the entire length of the lacrimal canaliculus where a diathermy needle could be inserted. After resection of the annulus fibrosus in the peri-punctal area, tight cross-stitch suturing of the puncta was performed with 8-0 absorbent thread. Visual acuity, corneal staining score according to the area (A) and density (D) classification, and Schirmer tear test (STT); tear break up time (tBUT); and subjective symptoms assessed by the University of North Carolina (UNC) and Dry Eye Management Scale were compared before and one year after surgery. Results: Recanalization occurred in 1/20 puncta (5.0% at month 5) in 1/11 eyes. Student’s t-test showed significant improvement at one year compared with preoperative values for LogMAR value (P = 0.019), corneal staining score A (P = 0.00003) and D (P = 0.0003), STT (P = 0.004), and subjective symptoms (P = 0.015). No change was shown in tBUT and no serious adverse event occurred. Conclusion: This improved, minimally invasive surgical procedure has a low recanalization rate and achieves both objective and subjective improvements at one year. Keywords: Cauterization; Dry Eye; Lacrimal Canaliculi; Lacrimal Puncta; Punctal Occlusio

Tailoring swelling of alginate-gelatin hydrogel microspheres by crosslinking with calcium chloride combined with transglutaminase

lginate-based hydrogels can find uses in a wide range of applications, including in the encapsulation field. This type of hydrogels is usually ionically crosslinked using calcium sources giving rise to products with limited internal crosslinking. In this work, it is hypothesized that the combination of alginate crosslinked by calcium chloride (external crosslinking; ionic mechanism) with gelatin crosslinked by transglutaminase (internal crosslinking; enzymatic induced mechanism) can be used to tailor the swelling behavior of alginate-based hydrogel microspheres. A systematic study was conducted by covering process variables such as gelatin content, TGase concentration, and CaCl2 contact time, added by statistic tools as central composite rotatable design (CCRD), principal component analysis (PCA) and multiobjective optimization, to map their effect on the resulting water content after production (expressed as swelling ratio), and swelling properties at pH 3 and 7. Among the studied variables, particle's swelling was mostly affected by the gelatin content and transglutaminase concentration.This work was financially supported by Associate Laboratory LSRELCM (UID/EQU/50020/2019) funded by national funds through FCT/ MCTES (PIDDAC), and Foundation for Science and Technology (FCT, Portugal) and by CIMO (UID/AGR/00690/2019) trough FEDER under Program PT2020. The authors are grateful to CAPES, CNPq and Fundação Araucária for the support and also to Ajinomoto Foods Europe S.A.S. (France) for kindly provide the transglutaminase sample used in this work. I.P. Fernandes thanks the national funding by FCT, P.I., through the institutional scientific employment program-contract for her contract.info:eu-repo/semantics/publishedVersio

Heat and pH stable curcumin-based hydrophylic colorants obtained by the solid dispersion technology assisted by spray-drying

Natural food colorants are on demand due to food safety concerns related with some synthetic counterparts. Health-friendly alternatives can be available from plant sources, which include curcumin extracted from Curcuma longa L. However, its industrial use is difficult to achieve due to the low water affinity, pH and thermal instability, which is particularly challenging, e.g. for baked foods. In this work, the solid dispersion technique followed by spray-drying, an emergent approach in the context of colorants, was applied to curcumin using k-carrageenan, poly(vinyl alcohol) and polyvinylpyrrolidone, as the encapsulant materials. An orthogonal central composite design with dummy-variables was applied, and principal component analysis (PCA) and hierarchical cluster analysis (HCA) carried out to identify the experimental conditions leading to the most effective formulations. In general, particles with a wide range of pH and heat stability have been produced depending on the chosen encapsulant material, used formulation (curcumin, surfactant and polymer contents), and synthesis conditions (pH). Moreover, the used mathematical approach showed to be a valuable tool to support the development of tailor-made formulations directed to specific applications where pH and temperature are relevant processing parameters.This work was financially supported by Associate Laboratory LSRE-LCM (UID/EQU/50020/2019) funded by national funds through FCT/MCTES (PIDDAC), and Foundation for Science and Technology (FCT, Portugal). CIMO (UID/AGR/00690/2019) through FEDER under Program PT2020. Authors thank CAPES (Brazil), CNPq (Brazil) and Fundação Araucária (Brazil) for the support.info:eu-repo/semantics/publishedVersio