Syftet med denna studie är att undersöka hur undervisningen i årskurs F-6 kan utformas för att stödja elevers begreppsbildning inom de naturorienterande ämnena. Studiens syfte är även att studera hur lärarna riktar elevers uppmärksamhet i meningsskapandet av naturvetenskapliga begrepp och fenomen i undervisningen. Studie har genomförts genom intervjuer och observationer av fyra lärare. Intervjuerna har bearbetats och analyserats med en innehållsanalys medan observationerna har analyserats utifrån EMA-riktningsgivare. Resultatet från intervjuerna visar att arbetssätten samtal, praktiskt arbete, grupparbete, återkoppling till vardag och varierande arbetssätt beskrivs av lärarna som stödjande för elevernas begreppsbildning i NO-ämnena. I samband med detta beskriver även lärarna vikten av att låta eleverna resonera och diskutera kring NO-begrepp tillsammans. Resultatet av observationerna indikerar att även om lärarna i studien använde riktningsgivare på olika sätt fanns ändå gemensamma drag för i vilka sammanhang lärarna använde riktningsgivarna. Lärarna använde exempelvis genererande riktningsgivare i samband med praktiskt arbete, samtal och grupparbete genom frågor till eleverna. / <p>NO</p><p>Naturorienterande ämnen</p><p>naturorienterande ämnenas didaktik</p>

A ema (Rhea americana americana) é uma ave que pertence ao grupo das Ratitas, ordem Rheiforme e a família Rheidae. Neste trabalho foram analisadas as características morfológicas, macroscópicas e microscópicas, dos órgãos do aparelho reprodutor masculino (testículos, epidídimos, ductos deferentes e falo) e a cloaca em 23 emas, quatro filhotes com duas semanas, sete jovens (de três a oito meses) e doze adultas (três anos), provenientes do abatedouro da Cooperativa Emas do Brasil, RS e do CEMAS, Mossoró, RN. Fragmentos de cada órgão foram fixados por imersão em formoldeído 10%, tampão fosfato pH 7,4, 0,1M ou em solução de Karnovsky (paraformoldeído 4% e glutaraldeído 2,5%, tampão fosfato pH 7,4, 0,1M) e processados na rotina para microscopia de luz e eletrônica de varredura, respectivamente. Os testículos da ema possuem formato alongado e localizam-se na cavidade celomática, na região intra-abdominal dorsal, com comprimento e largura médias de 7,6 ± 1,2 cm e 2,6 ± 0,7 cm nos adultos; 4,5 ± 1,5 cm e 0,9 ± 0,4 cm nos jovens; e 0,8 ± 0,3 cm, e 0,2 ± 0,1 cm nos filhotes. O testículo está envolto pela túnica albugínea e seu parênquima possui túbulos seminíferos, compostos por epitélio espermatogênico e por células de sustentação, e pelo tecido intersticial, com as células endócrinas intersticiais, tecido conjuntivo frouxo e vasos. Nos adultos observaram-se todas as células da linhagem espermatogênica, enquanto nos jovens com 3 meses os testículos apresentaram túbulos seminíferos com luz reduzidas, espermatogônia e células de sustentação indiferenciadas. O epidídimo apresentou-se alongado e fusiforme junto a margem medial do testículo. Os ductos eferentes possuem um epitélio pseudoestratificado colunar ciliado baixo, enquanto no ducto epididimário o epitélio é alto. O ducto deferentes apresentou trajeto sinuoso nos adultos, retilíneo nos jovens, convoluto na sua porção média, diminuindo seu formato sigmóide em sua porção caudal, próximo à cloaca. O epitélio é pseudoestratificado reveste a luz irregular nos adultos, e circular nos jovens, mantendo proximidade com o ureter. A cloaca dividiu-se em três segmentos: o coprodeu, o urodeo e o proctodeo. No urodeu os ductos deferentes desembocaram em papilas na parede ventro-lateral, próximo a inserção do falo fibroso. O falo é um órgão fibroso linfático, localizado na parede ventral, no assoalho da cloaca, e apresentou duas porções: uma rígida bifurcada e contorcida, e outra simples espiralada e flexível, a qual normalmente esteve invertida. De forma geral os órgãos reprodutores das emas compartilharam da morfologia de outras aves, principalmente aquelas descritas para os avestruzes. / The ema (Rhea american american) is a bird that belongs to the group of the Ratitas, order Rheiforme and family Rheidae. At this study were analyzed the morphological characteristics, macroscopic and microscopic, of the male genital organ (testes, epididymis, deferent ducts, and fhallus) and the cloaca in 23 emas, four chicken (two weeks old), young witer three to ten months old and twelve adult animals (three years old), originating from Cooperativa Emas do Brasil, RS and also from CEMAS, Mossoró, RN. Slices from each organ were fixed by immersion in phorformaldehyde 10%, or in Karnovsky solution (phorformaldehyde 10%, buffer phosphate pH 7.4, 0.1M and glutaraldehyde 2.5% buffer phosphate pH 7.4, 0.1M) and processed for light and scanning microscopy, respectively. The testis of rhea had elongated shape and were located inside coelomatic cavity, in dorsal region of abdominal cavity, with medium length and width of 7.6 ± 1.2 cm and 2.6 ± 0.7 cm at adult animals; 4.5 ± 1.5 cm and 0.9 ± 0.4 cm at young animals; and 0.8 ± 0.3 cm, and 0.2 ±0.1 cm at chicken. The testis were recovered by the tunica albuginea and its parenchyma had seminiferous tubules composed by spermatogenic epithelium and by sustentation cells, and also interstitial tissue, with interstitial endocrine cells, connective tissue and vessels. At the adult animals were observed all the cells from spermatogenic lineage, whilst at the youngs with 3 months the seminiferous tubules had a smale lumen with spermatogonia and undifferentiated sustentacular cells. The epididymis was elongated and fusiform closely to medial testis board. The efferents ductus were composed by a low ciliated pseudoestratified epithelium, while the epididimydis duct had a light epithelium. The deferent duct had sinuous stretch at adult animals, rectilineae at young animal, convolute at its medium portion, decreasing its sigmoid shape at caudal portion, next to cloaca. The epithelium was pseudostratified ciliated, irregular lumen at adult animal, and circular at young animal, closely with urether. The cloaca was divided into three segments: coprodeum, urodeum and proctodeum. At urodeum the deferent ducts discharged into papillas at the ventral side wall, next to fibrous phallus`s insertion. The phallus was a lymphatic fibrous organ, located at ventral wall, at the cloaca floor, and was composed by two portions: one rigid forked and twisted, and another simple spiraled and flexible, which normally was inverted. In a general way the Rhea genital organs shared the morphology from others birds, mainly those described to the ostrich.

O objetivo do presente estudo foi avaliar o desempenho, saúde intestinal e metabolizabilidade de dietas para frangos de corte alimentados com o uso contínuo ou mudança brusca de diferentes rações à base de milho e sorgo moído ou inteiro. No Exp. 1 foi estudada a mudança no tipo de grão com as dietas: M100% (ração à base de milho); S100% (ração à base de sorgo); M:S50% (ração à base de 50% milho e 50% sorgo); PS-M (ração à base de sorgo na fase pré-inicial e milho nas demais fases); PM-S (ração à base de milho na fase pré-inicial e sorgo nas demais fases). No Exp. 2 foi estudada a mudança na forma do grão de sorgo: Sm100% (ração à base de sorgo moído); Si100% (ação à base de sorgo inteiro); PSm-Si (ração à base de sorgo moído na fase pré-inicial e inteiro nas demais fases) e PSi- Sm (ração à base de sorgo inteiro na fase pré-inicial e moído nas demais fases). Os experimentos foram conduzidos em um delineamento em blocos casualizados (blocos no tempo) para avaliar o desempenho e epitélio jejunal (r=8), microbiota intestinal (r=4) e metabolizabilidade das dietas (r=10). As mudanças entre milho e sorgo não alteraram o desempenho, epitélio jejunal nem a metabolizabilidade das rações, mas influenciaram a porcentagem de Clostridium, Weissella, Bacillus e Alkaliphilus no intestino delgado e Lactobacillus e Desulfotomaculum nos cecos. O uso de sorgo inteiro piorou o desempenho aos sete dias. Aos 40 dias, Sm100% e PSm-Si apresentaram desempenhos semelhantes, PSi-Sm apresentou menor ganho de peso, mas melhor conversão alimentar e Si100% apresentou o pior desempenho. Si100% e PSm-Si apresentaram aumento no peso relativo da moela e na metabolizabilidade das rações, assim como diminuição de Clostridium e aumento de bactérias das famílias Actinomycetales e Bacillales no intestino delgado, Si100% resultou em menor porcentagem de Alkaliphilus e Enterococcus que Sm100% nos cecos. Conclui-se que a melhor estratégia de uso do sorgo é a substituição total de milho por sorgo moído ao alojamento com posterior mudança para sorgo inteiro, pois não afeta o desempenho e epitélio jejunal das aves, melhora a metabolizabilidade das rações e potencializa a redução de Clostridium no intestino delgado de frangos de corte. / The aim of this study was to evaluate performance, intestinal health and metabolizability of diets in broilers fed different corn- or sorghum (ground or whole)- based diets, continuously or with abrupt change between the diets. Exp. 1 - Change in the type of grain: C100% (corn-based diet); S100% (sorghum-based diet); C:S50% (50% corn and 50% sorghum-based diet); PC-S (corn-based diet in pre-starter phase and sorghum-based diet in other phases); PS-C (sorghum-based diet in pre-starter phase and corn-based diet in other phases). Exp. 2 - Change in the form of sorghum grain: Gs100% (ground sorghum-based diet); Ws100% (whole sorghum-based diet); PGs-Ws (ground sorghum-based diet in pre-starter phase and whole sorghum-based diet in other phases); PWs-Gs (whole sorghum-based diet in pre-starter phase and ground sorghum-based diet in other phases). Experiments were conducted in a randomized block design for to evaluate performance and jejunal epithelium (r=8), intestinal microbiota (r=4) and metabolizabilty of diets (r=10). The changes between corn and sorghum did not affect performance, jejunal epithelium or metabolizability of the diets, but influenced the genera Clostridium, Weissella, Bacillus and Alkaliphilus in the small intestine, and Lactobacillus and Desulfotomaculum in the caecum. Whole sorghum resulted in decreased performance at seven days of age. At 40 days, Gs100% and PGs-Ws showed similar performance, PWs-Gs showed lower weight gain and the best feed conversion rate, and Ws100% showed the worst performance. Ws100% and PGs-Ws resulted in the biggest gizzard relative weight and the highest diet metabolizability values, as well as the lowest level of Clostridium and highest level of Actinomycetales and Bacillales in the small intestine. Ws100% showed lower level of Alkaliphilus and Enterococcus than Gs100% in the caecum. The best strategy to use sorghum in broilers diets is replacing 100% of corn for ground sorghum since the first day followed by change to whole sorghum, because this diet did not affect performance or jejunal epithelium, improved diet metabolizability values, and reduced Clostridium in the small intestine of broilers.

Hearing loss can significantly hinder an individual's ability to engage socially and, when left untreated, can lead to anxiety, depression, and even dementia. The most common type of hearing loss is sensor-neural hearing loss that is treated using hearing aids (HAs). However, a significant fraction of individuals that may benefit from using HA do not use them and, the satisfaction of those that do, is only around 60%. Today, we have only a limited understanding regarding the factors that contribute to the low adoption and satisfaction rates. This is a limitation of existing laboratory-based assessment methods that cannot accurately predict the performance of HAs in the real-world as they do not fully reproduce the complexities of real-world environments. There four core contributions of my PhD thesis: i) the development new computer-based methods for assessing HAs in the real-world. Our approach is based on the insight that HA performance is intrinsically dependent on the context in which a HA is used. A context includes characteristics of the listening activity, social context, and acoustic environment. To evaluate this hypothesis, we have developed AudioSense, a system that uses mobile phones to jointly characterize the context of users and the performance of HAs. ii) We provide the first instance of characterization of the auditory lifestyle of hearing aid users, and the relationships that exist between the context and hearing aid outcomes. iii) We utilize the subjective data collected using AudioSense to build novel models that can predict the success of hearing aid prescriptions for new and experienced users. We also quantitatively prove the importance of collecting contextual information for evaluating hearing aids. iv) We use the objective audio data collected with AudioSense to predict contextual information like acoustic activity and noise level. This provides us a way to intelligently infer contextual information automatically and reduce the burden on the study participants.

La cryptologie est un moyen de protéger la confidentialité, d'assurer l'intégrité, ou d'authentifier un système, tandis que la cryptanalyse est le moyen de retrouver l'information secrète. Les algorithmes cryptographiques modernes tels que AES ou DES sont impossibles à attaquer au niveau mathématique. La fuite d'information liée aux fonctionnements de ces machines est devenue un moyen puissant de cryptanalyse pour retrouver la clé secrète. Ces attaques sont connues sous le nom d'attaques par canaux cachés. Ce travail de thèse tente de trouver une réponse aux questions suivantes : * Existe t'il une architecture dont la fuite d'information ne permet pas à l'attaquant de retrouver la clé plus vite que par la cryptanalyse classique ? * Jusqu'à quel point ces fuites sont-elles tolérables, et comment peut-on maximiser l'utilisation de ces machines sans compromettre leur secret ? * Quelles sont les métriques pour déterminer la vulnérabilité des circuits électroniques face à une multitude de méthodes d'attaques ? Récemment d'innombrables chercheurs ont posé ces questions pour les différentes catégories de circuits électroniques. Dans ce travail de thèse nous restreignons notre espace de recherche parmi les circuits de type "FPGA" et de type "asynchrone". L'atout principal des circuits FPGA est leur reconfigurabilité, qui peut être utilisée pour modifier l'implémentation de l'algorithme face à une attaque. Les circuits asynchrones ont de bonnes propriétés telles que la tolérance aux fautes, la décorrélation de la consommation avec le calcul, qui permettent de réduire la portée des attaques par canaux cachés.

Mobile appliances and especially smart cards have found more and more applications in the past two decades. A little more than ten years ago, the security of those devices still only relied on mathematical complexity and computational infeasibility to force cryptographic systems. Unfortunately, during the execution of cryptographic algorithms, unintentional leakage may be observed. Indeed, the power consumption or the electromagnetic emanations of the device are correlated to the encryption/decryption process. Those unintended channels are called “sidechannel”. Our work was not targeted at the discovery of new “side-channel” sources but rather at a thorough investigation of two of them: the power consumption and the electromagnetic emanation in the near-field domain. In this respect, we dealt with three different aspects of the problem: 1. We carried out many experiments on small microcontrollers but also on FPGAs in order to provide an explanation on the sources and on the set up of an efficient measurement process. Moreover, we provide the first XY scanning pictures of the electromagnetic field radiated by a small microcontroller. 2. Obtaining several measures of the observed side-channel, how is it possible to statistically analyzed these observations? We detail here the different methods available and we introduce an enhancement in the Template Attack process with Principal Component Analysis. 3. Finally, on the basis of this experience, we tried to answer the following question: “Is it possible to provide a theoretical tool to evaluate secure implementations?” The idea was to follow the notion of “Physical Computer” introduced by Micali and Reyzin. In this respect, we provide here two metrics that we consider necessary to evaluate both the strength of the adversary and the information held in the leakage. Respectively we choose the average success rate and the Shannon's mutual information.

The introduction of new species within the cattle sector has been growing and among the most representative animals in this sector is the ostrich (Struthio camellus). Although generating benefits, these activities are difficult to be deeply studied in terms of their physiology, pathology and clinics due to the speed they evolve. Many physiological parameters which are essential for the diagnosis of disturb and diseases are not available. Thus, the objective of this work was to outline the plasmatic protein electrophoresis profile of ostrich, as well as to identify differences among the fractions of these proteins among specific age groups. Blood samples of 72 ostriches were collected in different farms in Rio Grande do Sul. The samples were distributed in six groups, according to the animal s age and gender, in which 2 were chick, 2 young and 2 adults. These samples were submitted to the biuret method and to the electrophoresis, for quantification, separation and identification of proteins. Along the same line of study, there were also processed and analyzed 9 blood samples of adult rheas (Rhea americana) and a couple of emus (Dromaius novaehollandiae), these animals that, along with the ostrich, which also belong to the Struthioniformes order. The levels of Total Proteins (PPT) and the relation between Albumin and Globulin (A/G) were found and determined through the biuret method and the technique of electrophoresis. For each group of female ostrich chick, the average PPT was 2.23 ± 0.23g/dL, for male chick it was 2.40 ± 0.30g/dL, for young females the average was 3.67 ± 0.42g/dL and young males it was 3.90 ± 0.44g/dL; the adult females presented an average of 4.11 ± 0.65g/dL and the adult males, 4.07 ± 0.69g/dL. For the group of adult rheas were found average values of 5:22 ± 0.66 g / dL of total plasma proteins and 0.97 ± 0.24 for the relationship between albumin and globulins. For a couple of emus, in turn, resulted in values of 5.30 g / dL and 4.10 g / dL of plasma total protein and 0.67 and 0.81 for the ratio of albumin and globulin, for female and male respectively. The protein fractions were defined as albumin, alpha-globulin, beta 1-globulin, beta2-globulin e gamma-globulin for the three species. / A introdução de novas espécies dentro do setor pecuário vem crescendo e entre os animais que figuram, com importância, está o avestruz (Struthio camellus). Essas atividades geram benefícios, mas, a velocidade com que evoluem dificulta o acompanhamento de estudos aprofundados e seguros sobre fisiologia, patologia e clínica desses animais. Muitos parâmetros fisiológicos não estão disponíveis, sendo estes imprescindíveis para o diagnóstico de distúrbios e enfermidades. Desse modo, o objetivo deste trabalho foi traçar o perfil eletroforético de proteínas plasmáticas de avestruzes, bem como identificar diferenças nas frações dessas proteínas entre determinadas faixas etárias. Para tanto, foram coletadas amostras de sangue de 72 avestruzes de diferentes criatórios do Rio Grande do Sul, distribuídos em seis grupos, por idade e por sexo, sendo 2 de filhotes, 2 de juvenis e 2 de adultos. Essas amostras passaram pela realização do método de biureto e pela eletroforese, para a quantificação, separação e identificação das proteínas. Dentro da mesma linha de estudo, foram processadas e analisadas 9 amostras de sangue de emas (Rhea americana) adultas e de um casal de emus (Dromaius novaehollandiae), animais esses que, junto com o avestruz, também pertencem à ordem Struthioniformes. Foram encontrados e determinados os níveis de proteínas plasmáticas totais (PPT) e a relação entre albumina e globulinas (A/G), por meio da realização do método de biureto e da técnica da eletroforese. Para o grupo de avestruzes filhotes fêmeas, a média de PPT foi de 2.23 ± 0.23g/dL, para os filhotes machos foi 2.40 ± 0.30g/dL; para as fêmeas juvenis a média foi de 3.67 ± 0.42g/dL e para os machos juvenis foi 3.90 ± 0.44g/dL; as fêmeas adultas, por sua vez, apresentaram uma média de 4.11 ± 0.65g/dL e os machos adultos, 4.07 ± 0.69g/dL. Para o grupo das emas foram encontradas médias de valores de 5.22 ± 0.66 g/dL de proteínas plasmáticas totais e 0.97 ± 0.24 para a relação entre a albumina e as globulinas. Para o casal de emus, por sua vez, obteve-se valores de 5,30 g/dL e 4,10 g/dL de proteínas plasmáticas totais e 0,67 e 0,81 para a relação entre a albumina e as globulinas, para a fêmea e o macho respectivamente. As frações protéicas, nesse estudo, foram definidas como albumina, alfa-globulina, beta1-globulina, beta2-globulina e gama-globulina, para as três espécies.

A ema (Rhea americana americana) é uma ave que pertence ao grupo das Ratitas, ordem Rheiforme e a família Rheidae. Neste trabalho foram analisadas as características morfológicas, macroscópicas e microscópicas, dos órgãos do aparelho reprodutor masculino (testículos, epidídimos, ductos deferentes e falo) e a cloaca em 23 emas, quatro filhotes com duas semanas, sete jovens (de três a oito meses) e doze adultas (três anos), provenientes do abatedouro da Cooperativa Emas do Brasil, RS e do CEMAS, Mossoró, RN. Fragmentos de cada órgão foram fixados por imersão em formoldeído 10%, tampão fosfato pH 7,4, 0,1M ou em solução de Karnovsky (paraformoldeído 4% e glutaraldeído 2,5%, tampão fosfato pH 7,4, 0,1M) e processados na rotina para microscopia de luz e eletrônica de varredura, respectivamente. Os testículos da ema possuem formato alongado e localizam-se na cavidade celomática, na região intra-abdominal dorsal, com comprimento e largura médias de 7,6 ± 1,2 cm e 2,6 ± 0,7 cm nos adultos; 4,5 ± 1,5 cm e 0,9 ± 0,4 cm nos jovens; e 0,8 ± 0,3 cm, e 0,2 ± 0,1 cm nos filhotes. O testículo está envolto pela túnica albugínea e seu parênquima possui túbulos seminíferos, compostos por epitélio espermatogênico e por células de sustentação, e pelo tecido intersticial, com as células endócrinas intersticiais, tecido conjuntivo frouxo e vasos. Nos adultos observaram-se todas as células da linhagem espermatogênica, enquanto nos jovens com 3 meses os testículos apresentaram túbulos seminíferos com luz reduzidas, espermatogônia e células de sustentação indiferenciadas. O epidídimo apresentou-se alongado e fusiforme junto a margem medial do testículo. Os ductos eferentes possuem um epitélio pseudoestratificado colunar ciliado baixo, enquanto no ducto epididimário o epitélio é alto. O ducto deferentes apresentou trajeto sinuoso nos adultos, retilíneo nos jovens, convoluto na sua porção média, diminuindo seu formato sigmóide em sua porção caudal, próximo à cloaca. O epitélio é pseudoestratificado reveste a luz irregular nos adultos, e circular nos jovens, mantendo proximidade com o ureter. A cloaca dividiu-se em três segmentos: o coprodeu, o urodeo e o proctodeo. No urodeu os ductos deferentes desembocaram em papilas na parede ventro-lateral, próximo a inserção do falo fibroso. O falo é um órgão fibroso linfático, localizado na parede ventral, no assoalho da cloaca, e apresentou duas porções: uma rígida bifurcada e contorcida, e outra simples espiralada e flexível, a qual normalmente esteve invertida. De forma geral os órgãos reprodutores das emas compartilharam da morfologia de outras aves, principalmente aquelas descritas para os avestruzes. / The ema (Rhea american american) is a bird that belongs to the group of the Ratitas, order Rheiforme and family Rheidae. At this study were analyzed the morphological characteristics, macroscopic and microscopic, of the male genital organ (testes, epididymis, deferent ducts, and fhallus) and the cloaca in 23 emas, four chicken (two weeks old), young witer three to ten months old and twelve adult animals (three years old), originating from Cooperativa Emas do Brasil, RS and also from CEMAS, Mossoró, RN. Slices from each organ were fixed by immersion in phorformaldehyde 10%, or in Karnovsky solution (phorformaldehyde 10%, buffer phosphate pH 7.4, 0.1M and glutaraldehyde 2.5% buffer phosphate pH 7.4, 0.1M) and processed for light and scanning microscopy, respectively. The testis of rhea had elongated shape and were located inside coelomatic cavity, in dorsal region of abdominal cavity, with medium length and width of 7.6 ± 1.2 cm and 2.6 ± 0.7 cm at adult animals; 4.5 ± 1.5 cm and 0.9 ± 0.4 cm at young animals; and 0.8 ± 0.3 cm, and 0.2 ±0.1 cm at chicken. The testis were recovered by the tunica albuginea and its parenchyma had seminiferous tubules composed by spermatogenic epithelium and by sustentation cells, and also interstitial tissue, with interstitial endocrine cells, connective tissue and vessels. At the adult animals were observed all the cells from spermatogenic lineage, whilst at the youngs with 3 months the seminiferous tubules had a smale lumen with spermatogonia and undifferentiated sustentacular cells. The epididymis was elongated and fusiform closely to medial testis board. The efferents ductus were composed by a low ciliated pseudoestratified epithelium, while the epididimydis duct had a light epithelium. The deferent duct had sinuous stretch at adult animals, rectilineae at young animal, convolute at its medium portion, decreasing its sigmoid shape at caudal portion, next to cloaca. The epithelium was pseudostratified ciliated, irregular lumen at adult animal, and circular at young animal, closely with urether. The cloaca was divided into three segments: coprodeum, urodeum and proctodeum. At urodeum the deferent ducts discharged into papillas at the ventral side wall, next to fibrous phallus`s insertion. The phallus was a lymphatic fibrous organ, located at ventral wall, at the cloaca floor, and was composed by two portions: one rigid forked and twisted, and another simple spiraled and flexible, which normally was inverted. In a general way the Rhea genital organs shared the morphology from others birds, mainly those described to the ostrich.

Abstract While numerous publications deal with the properties and applications of porous silicon (PS), some of the related topics are not complete or could be investigated from different aspects. Therefore, the main objective of this thesis is to provide novel information associated with the optical and chemical properties of PS. For the investigations, various PS samples are manufactured by electrochemical dark etching of boron-doped p+-type Si wafers. Amongst others, (i) the wavelength-dependent refractive indices of freestanding PS monolayers having different porosities were obtained from optical transmission and reflection spectra in the 700–1700 nm wavelength range, and compared to those calculated from Bruggeman's effective medium approximation (EMA). The refractive indices of the PS samples are shown to be described well with the EMA. In addition, optical scattering at the air-PS interface was demonstrated. (ii) Multilayer stacks are created by alternating the porosities of PS layers within the same sample to form Bragg filters. The Bragg conditions of the filters are calculated and compared to optical transmission measurements. (iii) The oxidation of PS membranes in dry air is investigated with emphases on the reaction kinetics and on the structural changes of the porous matter. As revealed, oxidation proceeds faster in PS than in Si bulk. The formed SiO2 is amorphous and causes stress in the lattice of the residual Si skeleton. (iv) The effect of oxidation extent of PS layers on the growth mechanism of multi-walled carbon nanotubes (CNTs) is investigated. The density of the CNT network is found proportional to the oxidation extent of the substrates. (v) Finally, the chemically-reductive nature of PS is studied and exploited via the immersion plating method to deposit palladium and silver nanoparticles in the nanopores and on the surface of PS samples. The presented novel results have potential in silicon-based technologies, including integrated active and passive optical components (waveguides, filters, antireflection coatings, optical gas/liquid sensors), electronic devices (electrochemical gas/liquid sensors, diodes, field effect devices) and selective chemical catalysis (substrates, growth templates).

Magister Pharmaceuticae - MPharm / Medicines (CMs) are widely available to the South African public. However, CMs have not yet been evaluated by the Medicines Control Council (MCC). The MCC has published new guidelines for the regulation of CMs, with which CM companies are required to comply. OBJECTIVE: Determine to what degree Western Herbal CM labelling complies with the MCC’s requirements. METHODS: Thirteen CM products containing recognised Western Herbal ingredients were selected from pharmacies in the northern suburbs of Johannesburg. Labelling information on the immediate and outer container labels, as well as the package inserts, was investigated. The relevant corresponding European Medicines Agency (EMA) monographs and MCC guidelines were used to assess compliance. RESULTS: None of the products complied with the product dosage section of the monographs. Furthermore, the products contained indications that were not present in the monographs. The products did not fully meet the MCC’s mandatory minimum labelling requirements, and they did not demonstrate total compliance with all of the MCC’s requirements for product labels and package inserts.