This thesis deals with the study of the drinking regime for second primary school students and high school students with a focus on drinking schedule at school. The work is divided into theoretical and practical part. In the introduction to the theoretical part there has been characterized the target group. Furthermore, there's given the importance of water for the human body, water balance, principles of drinking regime and specific recommendations for the target group. Furthermore, there's been made a recherche out of several different sources regarding particular nonalcoholic drinks. In the conclusion, the attention is paid to the risks that may be occured due to improper intake of liquids and also to providing the drinking regime in school. The practical part of the thesis describes the research which was done among students and teachers. The way to data collection were questionnaires. Particular results are presented and discussed in the conclusion of the thesis. The results of the survey determine that, although some awareness of the monitored group of students is apparent, keeping the drinking regime principles is unsatisfactory. Based on the research and information from available literature, there've been formulated recommendations for teaching practice.

A research report submitted to Wits Business School, Faculty of Commerce, Law and Management, University of the Witwatersrand, Johannesburg, in partial fulfilment of the Degree of Master of Management in Strategic Marketing November 2015 / Building, maintaining and measuring consumption frequency over a specific period of time has become the primary driver of success for nonalcoholic beverage organisations; however, there is limited research on youth consumption frequency within South Africa. Using the Theory of Planned Behaviour, the study aimed to investigate the impact of brand association, flavour variety, peer influence and perceived value on consumption frequency intention in the sparkling soft drink (SSD) category amongst youth in South Africa. A quantitative research design was followed and data collected from 300 research participants aged between 16 and 24 years in Soweto, Gauteng Province in South Africa. The collected data was analyzed using SPSS 22 and AMOS 21 statistical packages for structural equation modelling. All four hypotheses are supported, with results indicating a positive relationship between brand association, flavour variety, peer influence, perceived value and consumption frequency intention. Peer influence and perceived value have a significantly stronger influence on consumption frequency intention. The results also indicate that flavour variety “ambiguous SSD flavour names” scored higher amongst 16 to 18 years olds. Ambiguous flavour naming strategies have proven to be successful in other beverage categories. Quantity-frequency (QF), a consumption frequency measurement instrument has been used, with consumption skewed towards “sharing” with friends or family. This study contributes significant new knowledge to the existing body of marketing literature in Africa and consumer behaviour in emerging markets. This study has implications for practitioners, academicians and public policy makers. / MT2017

O achocolatado é um alimento bem aceito pelo mercado consumidor, sendo encontrado e consumido por todo o mundo. Outro fator importante no mercado de alimentos é a tendência de diminuição do uso de açúcar e o incentivo ao uso de adoçantes, com o intuito principal de atender aos consumidores em dieta com restrição de glicose e, ainda, de redução calórica; também a adequação dos produtos às exigências atuais de produtos mais saudáveis, já que o consumo de açúcar pode estar relacionado com o efeito negativo à saúde. Em vista da carência no mercado brasileiro de achocolatados em pó com características diferenciadas dos comumente comercializados, os objetivos principais deste projeto são desenvolver produtos achocolatados com formulações diferenciadas devido ao uso de espessantes, utilizando ainda dois tipos diferentes de processamento, bem como analisar as principais características envolvidas em sua formulação e produção através do entendimento das propriedades físicas. Foram utilizados como espessantes goma guar, goma tara, goma xantana e amido pré gelatinizado, além de stevia e isomalte como adoçantes variantes da sacarose. Foi testado e sugerido um método de instantaneização baseado na aplicação de álcool de cereal ao produto. Os resultados sugeriram que, para os produtos em estudo, o isomalte é um bom adoçante substituto à sacarose, diferentemente da stevia que apresentou resultados não satisfatórios. O processo de instantaneização proposto apresentou melhores resultados que o processamento convencional para os testes físicos aplicados (molhabilidade, solubilidade, ângulo de repouso, densidade acomodada, compactação, distribuição granulométrica) mostrando ser uma boa alternativa de processo para a obtenção de um produto de fácil reconstituição como os achocolatados devem ser, além de os adoçantes não terem mostrado influencia na viscosidade do produto, diferentemente do tipo de espessante, no qual a goma guar se mostrou mais viscosa em comparação aos outros espessantes. / Chocolate is a food well accepted by the consumer market, being found and consumed all over the world. Another important factor about food market is the tendency to reduce the use of sugar and the encourage the use of sweeteners, with the main aim to cater to consumers in dietary glucose restriction and also the calorie reduction, also the suitability of the products the current requirements of healthier products, since the sugar consumption may be related to the negative effect on health. In view of the shortage of chocolate powder with different characteristics in the common market of Brazil, the main objectives of this project are to develop chocolate products with different formulations due to the use of thickeners, even using two different types of processing and analyzing the main features involved in their design and production through the understanding of the physical properties. Were used as thickeners, guar gum, tara gum, xanthan gum and pre-gelatinized starch, and as sweeteners stevia and isomalt variants of sucrose. Was tested and suggested a instantization method based on the application of alcohol cereal to the product. The results suggested that, for the products studied, isomalt is a good substitute for sucrose, stevia unlike that showed unsatisfactory results. The instantisation process proposed gave better results than conventional processing for the physical tests applied (wettability, solubility, angle of repose, accommodated density, compaction, particle size distribution) showing be a good alternative process for obtaining a easy reconstitution product, as a chocolate drink must be, in addition the sweeteners have shown no influence on product viscosity, unlike the type of thickener, whose the guar gum was more viscous in comparison to other thickeners.

O achocolatado é um alimento bem aceito pelo mercado consumidor, sendo encontrado e consumido por todo o mundo. Outro fator importante no mercado de alimentos é a tendência de diminuição do uso de açúcar e o incentivo ao uso de adoçantes, com o intuito principal de atender aos consumidores em dieta com restrição de glicose e, ainda, de redução calórica; também a adequação dos produtos às exigências atuais de produtos mais saudáveis, já que o consumo de açúcar pode estar relacionado com o efeito negativo à saúde. Em vista da carência no mercado brasileiro de achocolatados em pó com características diferenciadas dos comumente comercializados, os objetivos principais deste projeto são desenvolver produtos achocolatados com formulações diferenciadas devido ao uso de espessantes, utilizando ainda dois tipos diferentes de processamento, bem como analisar as principais características envolvidas em sua formulação e produção através do entendimento das propriedades físicas. Foram utilizados como espessantes goma guar, goma tara, goma xantana e amido pré gelatinizado, além de stevia e isomalte como adoçantes variantes da sacarose. Foi testado e sugerido um método de instantaneização baseado na aplicação de álcool de cereal ao produto. Os resultados sugeriram que, para os produtos em estudo, o isomalte é um bom adoçante substituto à sacarose, diferentemente da stevia que apresentou resultados não satisfatórios. O processo de instantaneização proposto apresentou melhores resultados que o processamento convencional para os testes físicos aplicados (molhabilidade, solubilidade, ângulo de repouso, densidade acomodada, compactação, distribuição granulométrica) mostrando ser uma boa alternativa de processo para a obtenção de um produto de fácil reconstituição como os achocolatados devem ser, além de os adoçantes não terem mostrado influencia na viscosidade do produto, diferentemente do tipo de espessante, no qual a goma guar se mostrou mais viscosa em comparação aos outros espessantes. / Chocolate is a food well accepted by the consumer market, being found and consumed all over the world. Another important factor about food market is the tendency to reduce the use of sugar and the encourage the use of sweeteners, with the main aim to cater to consumers in dietary glucose restriction and also the calorie reduction, also the suitability of the products the current requirements of healthier products, since the sugar consumption may be related to the negative effect on health. In view of the shortage of chocolate powder with different characteristics in the common market of Brazil, the main objectives of this project are to develop chocolate products with different formulations due to the use of thickeners, even using two different types of processing and analyzing the main features involved in their design and production through the understanding of the physical properties. Were used as thickeners, guar gum, tara gum, xanthan gum and pre-gelatinized starch, and as sweeteners stevia and isomalt variants of sucrose. Was tested and suggested a instantization method based on the application of alcohol cereal to the product. The results suggested that, for the products studied, isomalt is a good substitute for sucrose, stevia unlike that showed unsatisfactory results. The instantisation process proposed gave better results than conventional processing for the physical tests applied (wettability, solubility, angle of repose, accommodated density, compaction, particle size distribution) showing be a good alternative process for obtaining a easy reconstitution product, as a chocolate drink must be, in addition the sweeteners have shown no influence on product viscosity, unlike the type of thickener, whose the guar gum was more viscous in comparison to other thickeners.

Bakgrund: Preoperativ fasta är nödvändigt innan anestesi för att reducera magsäckens innehåll och därmed minska risken för aspiration. Trots att internationella riktlinjer rekommenderar två timmars fasta för klar vätska är det många sjukhus som fortfarande använder sig av rutinmässig praxis att låta patienter fasta från midnatt. Detta kan innebära en onödigt lång fasta som ger patienten komplikationer i form av sekundära biverkningar och insulinresistens. Syfte: Att undersöka preoperativ omvårdnad i samband med fasta inför kirurgi. Metod: En litteraturstudie med beskrivande design bestående av 14 utvalda originalartiklar från databaserna Pubmed och Cinahl användes. Den teoretiska referensramen för denna studie var Katie Erikssons omvårdnadsteori gällande förståelse av lidande och lidandets drama. Resultat: Många patienter fastade längre än American Society of anesthesiologists (ASAs) rekommenderade riktlinjer. Att fasta längre än två timmar innan operation minskade inte risken för aspiration och gav inte någon mindre volym av magsäckens innehåll hos patienterna. Att ge patienter kolhydratrik dryck innan operation ökade patienternas pre- och postoperativa välbefinnande och innebar inga risker. Slutsats: Genom ett mer flexibelt arbetssätt vid planerad operation kan längden på fastan anpassas efter patientens individuella behov. I samband med planerad kirurgi kan kolhydratrik dryck vara ett bra komplement vid fasta för att minska patientens lidande. Sjuksköterskan är omvårdnadsansvarig och ska arbeta evidensbaserat samt se till patienternas bästa och tillgodose deras behov. Sjuksköterskan kan använda detta som underlag för att minska lidandet i samband med fastan. / Background: Preoperative fasting is necessary before anesthesia to reduce gastric contents and decrease the risk of aspiration. Although international guidelines recommend two hours fasting of liquids, many hospitals still practice nil-by-mouth after midnight. This might give an unnecessarily prolonged fasting which give the patient discomfort and insulin resistance. Aim:  To examine preoperative care in connection with fasting prior to surgery. Method: A literature study with descriptive design based on 14 original articles selected from the databases Pubmed and Cinahl was used. The theoretical frame of reference for this study was Katie Eriksson's nursing theory regarding understanding of suffering and the drama of suffering. Results: Many patients fast longer than American Society of anesthesiologists (ASAs) recommended guidelines. Fasting more than two hours before surgery did not decrease the risk of aspiration and did not decrease the gastric volume. To give patients a high carbohydrate drink before surgery increased the patient's pre- and postoperative comfort. Conclusion: Through a more flexible working method during the planned operation, the length of the fast can be adapted to the patient's individual needs. In conjunction with planned surgery, carbohydrate-rich beverages can be a good complement to fasting to reduce the patient's suffering. The nurse is responsible for nursing care and should work evidence-based and ensure the patients' best and meet their needs. The nurse can use this as a basis for reducing the suffering associated with fasting.

O presente estudo consistiu na formulação, no processamento em escala piloto, na avaliação da esterilidade comercial (EC) e no estudo da vida útil de um suplemento hidroeletrolítico (isotônico) elaborado com soro de ricota. O soro de ricota deslactosado foi pasteurizado a 75 ºC/15 s, acondicionado assepticamente em garrafas plásticas e estocado a 0 ºC para ser utilizado no desenvolvimento da formulação do isotônico. O desenvolvimento da formulação contendo soro de ricota, água deionizada, corante, aroma, sacarose e cloreto de sódio foi norteado pela aplicação de testes sensoriais de Ordenação-Preferência, de Escala do Ideal e testes físico-químicos. Utilizando-se um delineamento experimental fatorial, investigou-se o binômio tempo de retenção (30 a 50 s) x temperatura de pasteurização (85 a 95 ºC) adequado à obtenção de uma bebida comercialmente esterilizada com elevada aceitação sensorial. A estabilização da bebida foi baseada na seguinte combinação de métodos térmicos e não térmicos: acidificação, pasteurização e envase asséptico. Testes físico-químicos, sensoriais e microbiológicos, incluindo o teste de EC, foram realizados na bebida recém-processada (tempo zero do estudo da vida útil (VU)). Um terço, aproximadamente, de cada lote processado foi estocado a -18 ºC (amostras controle) e dois terços estocados a 25 ºC (amostras codificadas), na ausência de luz. A estimativa da VU da bebida foi fundamentada em testes microbiológicos e sensoriais. A avaliação da estabilidade microbiológica baseou-se na enumeração de bactérias aeróbias mesófilas e a estabilidade sensorial em testes de Escala Hedônica de nove pontos para avaliação da impressão global do produto. A formulação isotônica desenvolvida atendeu aos requisitos estabelecidos pela Legislação Alimentar Brasileira, com pH 3,15, teor de sólidos solúveis de 6,4 ºBrix, osmolalidade de 306 mOsm/kg água e níveis de sódio e de potássio equivalentes a 500 e 650 mg/L, respectivamente. A bebida recém-processada apresentou contagens de bactérias mesófilas aeróbias inferiores a 10¹ UFC/mL e as médias das notas obtidas nos testes de Escala Hedônica de nove pontos alcançaram 6 (gostei ligeiramente) para o aroma e para o sabor, e situaram-se entre 6 (gostei ligeiramente) e 7 (gostei moderadamente) para a aparência. A análise estatística dos resultados revelou que somente o tempo de retenção aplicado no tratamento térmico produziu efeito significativo (p < 0,05) no sabor da bebida recém-processada, não apresentando efeitos significativos para aroma, aparência, parâmetros de cor (L*, a* e b*), pH, acidez titulável e teor de sólidos solúveis. Somente os processamentos 3 (95 ºC/50 s), 4 (90 ºC/40 s) e 5 (85 ºC/30 s) alcançaram a EC e tiveram seus tempos de VU limitados pela depreciação sensorial, estimados em 100, 128 e 153 dias, respectivamente. Os tempos de VU estimados para os lotes dos processamentos 2 (95 ºC/30 s), 6 (85 ºC/50 s) e 7 (90 ºC/40 s) foram equivalentes a 70, 42 e 42 dias, respectivamente, tendo sido limitado pelo desenvolvimento de micro-organismos, resultando em alterações na aparência da bebida e no estufamento de algumas embalagens. O lote 1 (90 ºC/40 s) teve sua vida útil estimada em 128 dias devido a falta de amostras. O soro de ricota revelou-se uma alternativa tecnologicamente viável para elaboração de um suplemento hidroeletrolítico permitindo o aproveitamento e a agregação de valor ao referido subproduto. A combinação dos métodos empregados na estabilização da bebida foi eficiente para a redução da carga microbiana inicial e para a obtenção de uma bebida com boa aceitação sensorial. / This study focused the formulation, small scale processing, commercial sterility (CS) evaluation and shelf life (SL) study of a ricotta cheese whey (RCW) based sports drink (isotonic). The RCW was pre-treated with lactase, pasteurized at 75 ºC/15 s, aseptically filled into plastic bottles and stored at 0 ºC. Then it was used to develop the isotonic formulation (RCW, deionized water, coloring, flavor, sucrose and sodium chloride) by applying Rank Preference, Just Right Scale and physicochemical tests. A factorial experiment was designed to investigate the binomial holding time (30 to 50 s) and pasteurization temperature (85 to 95 ºC) appropriate for attaining a commercially sterilized drink with a high sensory acceptance. The drink stabilization was based on the combination of thermal and non-thermal methods: acidification, pasteurization and aseptic filling. Physicochemical, sensory and microbiological tests were performed in the freshly processed drink. Approximately one third of each processed batch was stored at -18 º C (control samples) and two thirds stored at 25 ºC (coded samples), in the dark. The estimate of the isotonic shelf life relied on the microbiological and sensory tests. The microbiological stability evaluation was based on the total mesophilic aerobic counts. The sensory stability study relied on a nine-point Hedonic Scale tests. The developed formulation met the Brazilian Food Legislation and obtained acceptance average scores of 6.3, pH 3.15, soluble solids of 6.4 ºBrix, osmolality of 306 mOsm/kg água, 500 mg/L of sodium and 650 mg/L of potassium. The freshly processed product presented mesophilic aerobic bacteria counts below 10¹ CFU/mL. The average of the ratings obtained for aroma and flavor in the nine-point Hedonic Scale tests reached 6 (liked slightly); it ranged from 6 (liked slightly) to 7 (liked moderately) for appearance. The statistical analysis showed that only the holding time applied to the heat treatment had significant effect (p < 0.05) in the flavor of the drink. Neither the holding time nor the pasteurization temperature affected other sensory attributes and physicochemical parameters. Only batches 3 (95 ºC/50 s), 4 (90 ºC/40s) and 5 (85 ºC /30 s) reached the commercial sterility; their shelf lives were limited by sensory depreciation and estimated at 100, 128 and 153 days, respectively. The shelf lives for batches 2 (95 ºC/30 s), 6 (85 ºC/50 s) and 7 (90 ºC/40 s) were 70, 42 and 42 days, respectively; they were limited by the microbial growth. The findings indicate that RCW could be a technologically feasible alternative to produce a sports drink. The combination of methods employed in this study was effective in reducing the initial microbial load and obtained a drink with good acceptance.

Salt sensitivity of blood pressure (BP) is an independent cardiovascular disease (CVD) and mortality risk factor, present in both hypertensive and normotensive population. Better understanding of this phenotype in healthy individuals may lead to more effective prevention of hypertension and CVD. Salt sensitivity is genetically determined and it may affect the relationship between salt taste perception and salt intake. This thesis, for the first time, comprehensively explored the associations between genetics, salt sensitivity of BP, salt taste perception and salt intake as well as the potential of using genetic information in salt sensitivity biomarker development. The study population comprised young to middle-aged, healthy adults. Salt sensitivity was defined as the change in BP after seven days of low-salt (51 mmol sodium/day) and seven days of high-salt diet (308 mmol sodium/day). Salt taste perception was identified using British Standards Institution sensory analysis method (BS ISO 3972:2011). Salt intake was assessed with a validated food frequency questionnaire and two 24-hour dietary recalls based on the 5-step multiple pass method. DNA was genotyped for single nucleotide polymorphisms (SNPs) in the SLC4A5, SCNN1B and TRPV1 genes coding for sodium and ion channels and transporters. Protein levels were measured from urinary exosomes with the focus, for the first time, on methods readily used in clinical setting, such as enzyme-linked immunosorbent assay (ELISA). Results showed that the participants with AA genotype of the rs7571842 (SLC4A5) exhibited the highest increase in BP (ΔSBP = 7.75 mmHg, p = 0.002). There was no association between genetics and salt taste perception as well as genetics and salt intake. No associations were observed between salt sensitivity of BP, salt taste perception and salt intake. These results warrant further investigation in a larger sample size study. Nevertheless, preference for salty taste or awareness of health risks related to increased salt intake may be a driver of salt intake in younger and healthy population and warrants further investigation. The involvement of SLC4A5 in salt sensitivity of BP, together with functional effects of the investigated SNPs, makes it a candidate for genetic and physiological marker of salt sensitivity. The ELISA measurement of its expression from urinary exosomes may serve as a method of choice in a clinical setting, if further optimised.

The increasing government and consumer interest in, and growing concerns about environmental issues have pressured businesses to adopt eco-innovative measures and activities. These pressures have been felt particularly by the food and drink sector in Scotland, a sector that is of considerable importance to the Scottish economy. To date, few studies have considered the challenges businesses in this sector face with regard to the adoption of eco-innovations. In particular, there has been little research on the challenges faced by the SMEs in the sector and how they are adopting eco-innovations. This study seeks to address this research gap through utilization of the diffusion of innovation theory to explore the adoption of eco-innovations by the Scottish food and drink SMEs. A qualitative survey of the website of 52 businesses was used to collect data and analysed using content analysis to generate five categories of eco-innovations namely; Waste, Energy, GSCM, Carbon and Embedding. This data collected informed the next phase of the research where in-depth interviews was conducted with 18 businesses to understand their eco-innovation adoption processes. The findings revealed two groups of attitudes among the participants namely; the positive and the sceptics. The main motivators to adoption were found to be; moral principles and beliefs, eco-consumer drive, cost saving, legislation and the creation of jobs and new opportunities. The major barriers to eco-innovation were more profound and found to include; non-recyclable waste, non-compliance by suppliers, cost of adoption, lack of interest, the challenge of finding credible and reliable sources, attitudes and behaviours, and a general lack of education and awareness. Using the categorisation of eco-innovations that emerged from the website data analysis, the research developed a scale of greenness reflecting the adoption of eco-innovation along with a classification of adopter types namely; advanced, intermediate and basic adopters. The thesis contributes to the theory of diffusion by illustrating ways to capture and evidence innovation adoption without dependency on the time element and enabled a classification of eco- innovation adopters. The contribution to methodology is viewed from the application of a qualitative approach that enabled the categorisation of the forms of eco-innovation which resulted in the model depicting eco-innovation adoption and the profiling tool for innovation diffusion. Practical contributions are offered to enable businesses to understand their adoption of eco-innovation through the use of the model, adopter type classification and the application of a best practice guide to facilitate adoption. Recommendations for policy, practice and further areas for research are also proposed within the thesis.

Aimer, boire et manger: c'est ainsi que se définit la « bonne vie » selon les fabliaux. L'idéal qui prévaut dans ces contes, profondément ancrés dans le monde matériel et centrés sur des préoccupations charnelles plutôt que spirituelles, est en effet celui la satisfaction des désirs corporels, de la recherche des plaisirs charnels et de la jouissance. L'alimentation, la boisson et la sexualité y sont si bien représentées que la bonne vie peut être envisagée comme un élément constitutif, voire un trait définitoire du fabliau. Omniprésente, elle se place incontestablement au carrefour d'un nombre important de problématiques et de traits caractéristiques du genre. Plus qu'un simple thème unificateur du corpus, elle a de véritables implications rhétoriques et stylistiques. Son écriture, qui se révèle stéréotypée et qui reste « en surface », traduit l'ancrage du fabliau dans le monde matériel, concret et quotidien et contribue à la construction de l'idéal de plaisir et de satisfaction immédiate, aisément accessible à l'ensemble des estats de la société, que véhiculent ces contes. Il existe ainsi une véritable « poétique de la bonne vie » dans les fabliaux. Toutefois, le monde qu'ils donnent à voir n'est pas exclusivement positif et joyeux et la mauvaise vie y a également sa place, en particulier au sein du système de valeurs propre au genre et fondé sur la recherche de l'équilibre et la morale de la compensation. Enfin, en apparaissant comme une autre voie possible qui s'inscrit, non pas en opposition, mais à côté de celles proposées par les genres contemporains, la bonne vie contribue à faire du fabliau un genre singulier au sein du paysage littéraire de l'époque. / Loving, eating, and drinking: that is how the fabliau defines “the good life”. The prevailing ideal of these tales, which are deeply rooted in the material world and preoccupied with the carnal instead of the spiritual, encompasses the search for sensual pleasures and the satisfaction of earthly desires. Ever-present, food, drink and sexuality are so well represented that the good life may be seen as an integral part of that which defines the fabliau. More than just a theme which unifies the corpus, its presence has definite rhetorical and stylistic implications. This writing of the good life, which uses stereotypes and thus remains on the descriptive surface of things, anchors the fabliau in the material world, in the concrete and the quotidian. It contributes to the creation of these tales’ hedonistic ideal, accessible to all levels of society, in which desires are immediately satisfied. The fabliaux thus transmit a veritable “poetics of the good life”. Nevertheless, the world these tales represent is not exclusively positive. A less joyful life also surfaces, especially as reflected in the genre’s value system, which seeks a balance between morality and compensation. As another possible path which runs not in opposition to but parallel to those offered by contemporary works, the good life helps to make the fabliau a singular genre at the heart of the period’s literary landscape.

[pt] Desenvolveu-se um modelo de simulação para trocadores de calor de placas soldadas (BPHE – Brazed Plate Heat Exchanger) operando em regime permanente em um sistema de refrigeração em cascata por compressão de vapor, ou seja, condensador, trocador de calor intermediário (ou condensador em cascata) e evaporador. O modelo adota o método de análise local, onde o trocador de calor é dividido em uma série de pequenos volumes de controle, para os quais as equações de troca de calor e de conservação de massa e de energia são aplicadas. Para o calculo dos coeficientes locais de transferência de calor e fator de atrito foram utilizadas correlações disponíveis na literatura, considerando as regiões de escoamento monofásico ou bifásico em cada um dos trocadores, Estas correlações cobrem valores de fluxo de calor entre 2,5 kW/m2 e 185 kW/m2, temperaturas de saturação entre 5 graus Celsius e 30 graus Celsius, e aplicam-se a geometrias com ângulos de corrugação entre 20 e 60 graus. Um programa computacional foi desenvolvido em FORTRAN para o cálculo do desempenho térmico dos trocadores de calor e das correlações de asida dos dois fluidos. Na simulação foram consideradas conhecidas as condições de entrada dos fluidos e a geometria do trocador. As propriedades termo-físicas dos fluidos foram calculadas utilizandose a mais recente versão do padrão NIST de referência de propriedades termodinâmicas e de transporte (REFPROP 9.0), permitindo a simulação dos trocadores de calor operando com uma vasta gama de refrigerantes. Os resultados da simulação foram comparados com os dados experimentais (condensador e evaporador) levantados por outros autores para os refrigerantes R22 e R290, tendose obtido boa concordância. Uma analise de sensibilidade para os trocadores de calor, utilizando os novos refrigerantes R1234yf e R1234ze, foi também realizada. / [en] A simulation model of brazed plate heat exchangers (BPHE) operating in steady-state in a cascade vapor compression refrigeration system has been developed. For this system the heat exchangers were the condenser, intermediate heat exchanger or cascade-condenser and evaporator. The model adopts a local analysis method, where the heat exchanger is divided into a series of small control volumes, to which the heat transfer rate equations and the fundamental of conservation of mass and energy equation. Local heat exchanger coefficients and friction factor are calculated using correlations available in literature, considering regions of single-phase or twophase flow for each one of the heat exchangers. These correlations have heat flux values ranging from 2,5kW/m2 to 185kW/m2, saturation temperatures from 5 degrees Celsius to 35 degrees Celsius and were applied to geometries with corrugation angle ranging from 20 degrees to 60 degrees. In order to calculate the thermal performance of the heat exchangers and the output conditions of the two fluids a computational program was developed in FORTRAN. This simulation considers known inlet conditions of the fluids and the geometry of the heat exchanger. The thermophysical properties of the refrigerants fluids were calculated using the version 7 of REFPROP, a package by NIST (National Institute of Standards and Technology), that allow for the simulation of heat exchangers with a wide operating range of refrigerants. The simulation results were compared with experimental data (condenser and evaporator) for R22 and R290 refrigerants, obtaining a good agreement. A sensibility analysis for heat exchangers, using the new R1234yf and R1234ze has also been carried out.