Focusing and delivery of laser radiation for nano- and microfabrication

The recent advances in nanotechnology and nanofabrication motivate the drive to achieve a tighter focusing of light; this requires a high numerical aperture (NA) optical system. The need for high optical resolution has led scientists to discover the use of optical microlens for improving the performance of high numerical aperture (NA) optical systems. By focusing the laser beam through a microlens, the width of the beam can be reduced according to the needs of the application. In this work, the laser beam was focused by a microspherical lens (NA=0.7) into 150 nm or by tapered fibre into 4 μm diameter spots. The measurements indicate the strong influence of tightly focused beams. This thesis comprises of three parts; the first results chapter investigates the choice of material by considering the material properties and feasibility of fabrication (chapter 2). It has been shown in previous studies that the glass transition temperature of the polymer is an important factor in determining the laser ablation rate. High glass transition temperatures make it a good material candidate for optical waveguides. Polycarbonate (PC), polymethylmethacrylate (PMMA), negative photoresist SU-8, and chitosan have been characterised to choose suitable material as a substrate for soft nanolithography (chapter 3). The choice of material due to the glass transition temperature of the material (from literature), material optical properties are investigated experimentally at the range of wavelength from 190 nm to 1000 nm. Laser ablation experiments on PC, PMMA, SU- 8 and chitosan using a 193 nm ArF laser over a fluence range of 10 mJcm−2 –1000 mJcm−2. The ablation threshold at 193nm was found to be 24, 110, 40, and 95 mJ.cm-2 for PC, PMMA, SU-8, and chitosan respectively. The photoresist SU-8 and chitosan were chosen as both materials are biocompatible, and have a high glass transition temperature. Optical properties measured for these materials found that both materials have much higher absorption coefficients (αSU-8 ~ 4.2×105m-1 and αchitosan ~3.3×105m-1) compared with PC and PMMA (αPC =1×105m-1 and αPMMA=2×105m-1 )at 193 nm.The second part of this thesis reports experimental and computational results of an irradiated laser microsphere supported on biocompatible materials; SU-8 photoresist and chitosan (chapter 3). An ArF excimer laser (193 nm wavelength) was used with 11.5 ns pulse width to modify the underlying substrate, producing a single concave dimple. Atomic force microscopy and scanning electron microscope measurements have been used to quantify the shape and size of laser inscribed dimple. The dimple has a diameter of 150 ± 10 nm FWHM and a depth of 190 ± 10nm on SU-8 compared to 180 ± 10 nm FWHM and a depth of 350 ± 10nm on chitosan due to the optical properties of the materials. Finite-difference time-domain (FDTD) simulations were carried out to simulate the propagation of 193 nm laser radiation, focussed by a 1 µm diameter silica sphere. Finite Element Method (FEM) simulations were carried out to calculate laser- induced temperature rise of the both SU-8 and Chitosan layer beneath the microsphere. The SiO2 microsphere acts as a small ball lens tightly focussing the laser radiation. Delivery of the focussed laser radiation locally heats the substrate beneath the microsphere. As a consequence, mass transport takes place, forming a nano dimple.The third part of this thesis presents the use of a CO2 laser (10.6 μm wavelength) for producing microlenses at the end of silica optical fibre (chapter 4). By focused CO2 laser beam, silica optical fiber is irradiated and heated to the softening points (1800 K) of the silica material. Surface tension and the parameters of the fabrication system shape the melted material into a spherical micro-lens or tapered fiber that remains joined to the optical fiber. Different core diameters (125, 400, 600, 1000, and 1500 μm) of multimode fibres have been used for this fabrication. The roughness of the microlens was reduced to less than 20 ± 1 nm roughness by polishing the surface with a CO2 laser at low power (1- 2 W). Throughout this work, different microlenses (ball/parabolic) and tapered fibres were fabricated at the end of silica optical fibre. The minimum spot diameter at FWHM was close to 160 μm and 110 μm for microball and parabolic lenses, respectively. While the tapers had the minimum waist diameters down to 4 μm and maximum taper length of ~ 3.5 mm using silica multi-mode fibre. Finally, the knife-edge technique and He-Ne laser beam (632.8 nm wavelength) were coupled into a fibre to investigate the properties of the microlenses which produced a minimum spot size of 5 ±1 μm at FWHM in the focal region of the tapered fibre lenses of 125, 400 and 600 μm core diameter of the fibre.As a result, Chitosan and SU-8 have been used as substrate materials for recording tightly focussed focal regions, 193nm ArF laser has been used to realise extremely small, 150nm diameter, Photonic Nano Jets (PNJ’s). FDTD optical simulations accurately predict the spatial properties of microsphere PNJ’s emitting at 193. CO2 laser (10.6 μm) radiation has been used to form tapers and spherical lenses on the distal end of optical fibres. Finally, tight focusing using microspheres and lensed optical fibres could be integrated on lab-on- chip platforms for applications such as optical trapping and cell membrane modifications. An important application related to the results of this study is that focusing laser light produces a force that can be used to remove or trap selected cells or large tissue areas from living cell culture down to a resolution of individual single cells and subcellular components similar to organelles or chromosomes, respectively.The nanostructures fabricated in this chapter can be refined to achieve specific dimensions in; diameter, depth, shape, and periodicity so they can be used as antireflective surfaces for solar-cell applications [1].or could be used in drug delivery [2]. While laser microbeams are frequently used for measurement or imaging of biological parameters as well as using the optical tweezer system for trapping or moving of cells, the future medical applications will be focused on micromanipulation or microdissection methods for delivering molecules or nano drugs into a cell [3]. Delivering such nano- drugs into cancer cells requires overcoming the cell membrane by focusing the laser. This phenomenon is named photoporation which is based on the generation of localized transient pores in the cell membrane using the photonic nano jet [4]

Quantification of condensed tannins in red wines by Fourier transform mid-infrared spectroscopy (FTIR)

Mestrado Vinifera EuroMaster - Instituto Superior de AgronomiaGrape-derived condensed tannins, also known as proanthocyanidins, are critical quality components for red wines. They have been subject of numerous studies in order to find a fast and reliable methodology for their quantification. In this work it has been tested the method using Fourier transform mid-infrared (FTIR) and chemometrics to quantify the amount of condensed tannins present in 88 different red wines, with the reference method of precipitation with methylcellulose. As well it has been provided a single laboratory validation of the method of fractionation of condensed tannins by reverse phase and quantification by reaction with vanillin. The models developed for the FTIR spectroscopy were not enough robust for the estimation of total condensed tannins, with low values of coefficient of determination and low RPD values (R2 cross-validation: 0,76 and RPD cross-validation: 1,86). Validation of the fractionation method showed good performance in precision, with values of coefficient of variance for the three fractions FIII, FII and FI respectively of 5,2%; 11,4% and 11,6% and values of reproducibility of 168,1; 32,9 and 3,4 mg/L of epicatechin equivalents, but it was not possible to perform effective recovery studie

Imaging-in-flow: digital holographic microscopy as a novel tool to detect and classify nanoplanktonic organisms

Traditional taxonomic identification of planktonic organisms is based on light microscopy, which is both time-consuming and tedious. In response, novel ways of automated (machine) identification, such as flow cytometry, have been investigated over the last two decades. To improve the taxonomic resolution of particle analysis, recent developments have focused on "imaging-in-flow," i.e., the ability to acquire microscopic images of planktonic cells in a flow-through mode. Imaging-in-flow systems are traditionally based on classical brightfield microscopy and are faced with a number of issues that decrease the classification performance and accuracy (e. g., projection variance of cells, migration of cells out of the focus plane). Here, we demonstrate that a combination of digital holographic microscopy (DHM) with imaging-in-flow can improve the detection and classification of planktonic organisms. In addition to light intensity information, DHM provides quantitative phase information, which generates an additional and independent set of features that can be used in classification algorithms. Moreover, the capability of digitally refocusing greatly increases the depth of field, enables a more accurate focusing of cells, and reduces the effects of position variance. Nanoplanktonic organisms similar in shape were successfully classified from images captured with an off-axis DHM with partial coherence. Textural features based on DHM phase information proved more efficient in separating the three tested phytoplankton species compared with shape-based features or textural features based on light intensity. An overall classification score of 92.4% demonstrates the potential of holographic-based imaging-in-flow for similar looking organisms in the nanoplankton range

Towards supramolecular heterojunctions : self-assembled hydrogen-bonded architectures for organic photovoltaic devices

Ces travaux ont pour but la conception et la synthèse de composants moléculaires photo-et électro-actifs programmés l’auto-organiser en hétérojonctions supramoléculaires actives en conversion photovoltaïque. L’utilisation de fullerène (C60) et d'oligothiophène portant des motifs de reconnaissances moléculaires par liaisons hydrogène permet la conception d’architectures supramoléculaires en ruban, optimisées pour la séparation et la transport de charges efficaces. L’étude de monocouches auto-assemblées portant des groupes de reconnaissance moléculaires permet de structurer la couche active et augmente la réponse photovoltaïque des dispositifs. La fabrication de cellules solaires organiques à l’état solide avec ces matériaux auto-assemblées a également été étudiée.The aim of this research is to focus on the implementation of supramolecular self-assembly of photo-and electro-active components programmed to self-organize into molecular heterojunctions for efficient light-to-electrical energy conversion. The incorporation of fullerene and oligothiophene appended with complementary hydrogen-bonding molecular recognition motifs allows the design of supramolecular architectures engineered to achieve efficient charge separation and transport. In addition, the incorporation of self-assembled monolayers bearing hydrogen-bonding molecular recognition end-groups on electrode surface further enhances the photovoltaic response of the functional supramolecular devices. The fabrication of solid-state organic solar cells with the self-assembled photoactive materials also has been investigated

Metal-Based Antireflective Coatings with Improved Durability for Ophthalmic Applications

Dans une ère de supraconducteurs et d’isolants topologiques, les matériaux typiques peuvent sembler comme il n’ont plus rien à nous offrir. Mais au contraire, la plasmonique a prouvé qu’avec de la physique classique et un concept ingénieux, les métaux peuvent produire des phénomènes optiques intéressants et inattendus, et a inspiré une multitude de nouveaux moyens d’utiliser les métaux en optique. Dans ce travail, nous avons tenté d’utiliser des couches métalliques pour améliorer la performance et la durabilité des lunettes. Plus précisément, le but était de produire un revêtement optique contenant une couche mince métallique permettant un effet antireflet important, et offrant une durabilité suffisante afin de résister à l’usage quotidien d’une paire de lunettes. Les revêtements antireflets (AR), ont été produits selon une architecture diélectrique-métaldiélectrique. L’argent (Ag) fût sélectionné pour la couche métallique en raison de ses propriétés optiques hautement désirables, même parmi les métaux nobles. Cela étant dit, l’utilisation de l’Ag apporte son lot de défis. Tout d’abord, les couches minces d’Ag tendent à former des îlots lorsque déposées sur un diélectrique; ces îlots mènent alors à une absorption indésirable par résonance plasmon localisée. De plus, l’Ag est susceptible chimiquement, pouvant être dégradé par le chlore dans les huiles naturelles de la peau ou l’oxygène de l’air ambiant. Ainsi ce travail traitait de deux aspects: la performance optique devait être contrôlée via la dynamique de croissance, sans introduire de susceptibilités à l’environnement et des mesures de protection devaient être implémentées tout en minimisant leur impact sur la transparence et la performance de l’AR. L’étude a été menée sur des échantillons produits par pulvérisation magnétron et par évaporation par faisceau d’électrons. La dynamique de croissance et les propriétés optiques des couches d’argent ont été étudiées par ellipsométrie spectroscopique in situ, ainsi que par des mesures de la résistance de feuille, par spectrophotométrie et par ellipsométrie ex situ. Les effets des différentes architectures et conditions de dépôt sur la nanostructure et la durabilité des revêtements ont été étudiés par diffraction de rayons-X et dans divers tests de durabilité standardisés conçus pour les lentilles ophthalmiques, tels que la résistance à l’abrasion, à la délamination, à l’humidité et à la corrosion dans une solution aqueuse de NaCl. Le recouvrement de l’Ag par un diélectrique et le dopage à l’aluminium se sont révélés être des mesures de protection insuffisantes.----------Abstract In an era of superconductors and topological insulators, common materials may sometimes seem like they have nothing left to offer. But on the contrary, the field of plasmonics has proved that, with classical physics and a clever concept, metals can provide us with interesting and unexpected optical phenomena and has inspired a multitude of novel uses for metals in optics. In this work, we have attempted to use metallic layers to improve both the performance and durability of eyeglasses. More precisely, the goal was to create an optical coating containing a thin metallic layer to enable a strong antireflective effect, while proving durable enough to survive the daily ordeals of a pair of glasses. Antireflective (AR) coatings were made following a dielectric-metal-dielectric architecture. Silver (Ag) was chosen to constitute the metal layer, due to its highly coveted optical properties even amongst noble metals. That being said, the use of Ag brings about challenges of its own. First, thin Ag layers tend to form islands when deposited on dielectrics; these islands then lead to undesirable absorption due to localized plasmon resonance. Moreover, Ag is susceptible to degradation by a host of chemicals, including the chlorine found in oils naturally coating our skin and the oxygen we breathe. Thus, the work was twofold: optical performance was to be improved through control of the film growth without introducing durability issues and protective measures were to be implemented while minimising their impact on coating transparency and AR performance. The study was performed on samples deposited by magnetron sputtering and electron beam evaporation. Growth dynamics and optical properties of silver films were studied by in situ spectroscopic ellipsometry, as well as ex situ ellipsometry, spectrophotometry and sheet resistance measurements. The effects of these different deposition conditions and architectures on the nanostructure and durability of the coatings were investigated by X-ray diffraction measurements and standardized durability tests designed for ophthalmic lenses, such as resistance to abrasion and delamination, humidity and corrosion in an aqueous NaCl solution. Coating Ag with a dielectric layer and aluminum doping both proved to be insufficient protective measures. The use of nickel (Ni) and chromium nitride (CrNx) based coatings of a few angstroms allow increased chemical and mechanical durability. By separating the Ni and CrNx depositions and using a zinc oxide (ZnO) seed layer, chemically and vii mechanically durable stacks with less than 11% absorption and 1% reflection in the visible spectrum were produced

Synthesis and characterization of copper chalcogenide nanoparticles and their use in solution processed photovoltaics

A Thesis submitted to the Faculty of Science, School of Chemistry at University of the Witwatersrand, in fulfilment of the requirements for the degree of Doctor of Philosophy. Johannesburg 2015Photovoltaic cells offer a good alternative to the fossil fuels. Several approaches are being analysed in order to have solar cells that are capable to conquer the energy market all around the world. Quantum dots (QDs) have already proven features that can be taken into account to improve the properties of solar cells. Metal selenide nanoparticles (NPs) possess semiconducting behaviours that can vary with their structural and optical properties evolving from their synthesis. The reaction parameters such as the method, time, solvent and precursors can affect the growth and nucleation of particles and thus impose on the properties of the synthesized materials. The performance of solar cells made of the synthesized metal selenides will then be dependent upon the properties of the NPs used as active layer. Furthermore, the electrical current generation also depends on the structure of the deposited active layer and its interface with other films to be assembled for the device. The binary copper selenide, ternary copper indium selenide (CISe), quaternary copper indium gallium selenide (CIGSe) and quinary copper zinc tin sulphur selenide (CZTSSe) NPs were synthesized via conventional colloidal method (CCM) and microwave assisted method (MAM). The MAM has a particular interest as it is less time consuming and can easily be a large scale synthesis. Photovoltaic devices were fabricated from the synthesized materials as proof of concept for photovoltaic activities. The CCM was used to optimize various parameters for the synthesis of each type of the chalcogenide materials as this is easily controllable than the ones from the sealed vessel from MAM. The dependency of properties of all copper chalcogenide NPs on the time, precursor concentration, temperature and solvent of synthesis have been demonstrated via various characterization techniques including ultraviolet-visible-near infrared spectroscopy, photoluminescence spectroscopy, X-ray diffractometry and transmission electron microscopy. The binary copper selenide was first synthesized and considered as a template for evaluation of the use of copper chalcogenide materials in solar cells. Relatively smaller copper selenide NPs with average sizes of 4.5 and 6.0 nm were obtained from conventional colloidal and microwave assisted methods respectively. The sample yielded from the microwave assisted method possessed less polydispersed NPs. The later had better crystallinity in which prevailed a single cubic Cu2Se phase. To the best of our knowledge this is the first evidence of defined shapes and nearly single phase of small sized copper selenide NPs synthesized by mean of the MAM. The copper selenide particles synthesized via this method were used to fabricate a Schottky device. The conditions of copper selenide synthesis were optimized to 250 oC, 30 iii min of CCM synthesis using oleylamine (OLA) and a Cu/Se ratio of 1:1. Nearly hexagonal facets with blue-shifted absorption band edge of monodispersed NPs sizing 4-8 nm in diameter were obtained. The synthesized copper selenide showed better crystallinity with a single cubic Cu2Se phase. A Schottky device using MAM synthesized copper selenide NPs as the semiconducting layer was fabricated at room temperature. The diode effect was demonstrated with the electrical parameters such as the ideality factor, barrier height and the series resistances extracted from the experimental current-voltage data using the thermionic theory and Cheung’s modification. The thermionic theory resulted in the ideality factor of 4.35 and the barrier height of 0.895 eV whilst the Cheung’s method resulted in the ideality factor, barrier height and series resistance of 1.04, 2.59 10-3 eV and 0.870 Ω respectively. The ternary copper indium selenide NPs showed that the MAM allowed the formation of copper rich NPs alongside secondary products. The synthesis of the ternary sample via CCM was optimized using uncapped precursors (no TOP was added) in OLA at 220 oC for 30 min. The synthesized CuInSe2 NPs possessed a large blue-shift in their absorption band edges and emission peaks. The nearly stoichiometric CuInSe2 particles with diameter sizes of 5-9 nm were found in tetragonal crystalline orientation. The cyclic voltametry (CV) and the absorption spectra showed a large blue-shifted energy gap, about 0.95 eV, an increase from the bulk, proving the quantum confinement effects of synthesized copper indium selenide quantum dots. The CuInSe2 NPs were thus used as absorbing materials in the quantum dot sensitized solar cell devices (QDSSCs). The QDSSC devices were assembled via treatment of the titanium oxide, quantum dot layers and their interface. This was done by the treatment of copper indium selenide surface with mercapto-propionic acid (MPA) and ethanedithiol (EDT) during the deposition of the quantum dots onto TiO2 films. The MPA treatment did not reveal positive effects on copper indium selenide thin film and the assembled device under our optimized working conditions. However the use of EDT allowed the improvement of electron transport. The short circuit current (Jsc), open circuit voltage (Voc) and fill factor (FF) obtained from the current-voltage (J-V) curves reached the values of 324 μA cm-2, 487 mV and 43% respectively, indicating that the investigated quantum dots possess electrical properties. For the quaternary copper indium gallium selenide, relatively small sized NPs were synthesized via CCM and MAM. The CCM synthesized CIGSe NPs were less agglomerated iv with a shorter tailing in absorption than those from MAM. The stoichiometric CuIn0.75Ga0.25Se2 showed less agglomerated and highly crystalline particles with a large blueshifted absorption band edge and a smaller full width at halth maximum (FWHM) of the emission peak compared to CuIn0.5Ga0.5Se2 and CuIn0.25Ga0.75Se2. The use of OLA as solvent of synthesis improved the growth and dispersivity of copper indium gallium selenide NPs. The particles with a large blue-shifted absorption band edge, a lattice of tetragonal phase, more monodispersed CIGSe and possessing an average size of 6.5 nm were obtained from CCM synthesis using OLA. The OLA as-synthesized CIGSe NPs were used in thin film for the assembly of QDSSC. The device exhibited electrical properties with the Jsc, Voc and FF of 168 μA cm-2, 162 mV and 33% respectively. The overall device performance was poor but may further be improved for further photovoltaic application. The quinary CZTSSe NPs possessed large blue-shifted absorption band edges of 450-460 nm than the bulk material (827 nm). The emission peak at 532 nm and similar FWHM of less than 50 nm were observed in samples from both CCM and MAM. More monodispersed crystals were obtained with both methods whilst the average particle sizes of 10 and 9 nm were yielded from MAM and CCM respectively. The nanoparticles crystallized in tetragonal lattices between copper zinc tin sulphide and copper zinc tin selenide crystals. However, the MAM gave more crystalline phases. The CV and the absorption spectra showed a blue shifted energy gap, about 0.21 eV increase from the buk which is located at 1.51 eV. This is indicative of the quantum confinement effects of synthesized NPs. The evidence of electrical properties was also shown in the QDSSCs fabricated using the MAM synthesized quinary QDs. This was done following the same treatments as for copper indium selenide devices. The Jsc, Voc and FF were found at the maxima of 258 μA cm-2, 395 mV and 38% respectively. The MPA and EDT treatments did not improve the device performance under our working conditions. Nevertheless, the electrical properties observed in the assembled device were indicative of promising efficient solar cells from synthesized CZTSSe NPs

PHYSIOLOGICAL RESPONSES OF WHITE GRAPE BERRIES TO SUNLIGHT EXPOSURE

Reflectance spectroscopy was used in 2013, to investigate about varietal behaviors to different agronomics condition: (i) composition and quantification of pigments by using non-invasive method; (ii) photosynthetic pigments assessment by new reflectance indices (iii) how different microclimatic bunch conditions could affect the appearance of sunburn. The experiment was performed in the Regional Research Station of Riccagioia (Lombardy region, Northern Italy), at the University of Milan, on 16 white grape accessions, during 3 phenological stages: pre-veraison (77 BBCH), veraison (81 BBCH) and harvest (89 BBCH). New specific indices for the evaluation and estimation of photosynthetic pigments were proposed on the basis of grape berry reflectance spectra. Validations with classical extraction analysis were done. About 200 berries were analyzed (over 1000 reflectance spectra were collected). First the chlorophyll a and b absorption maxima in the reflectance spectra were established: 675 and 650 nm respectively. These new equations are also able to discriminate between chlorophyll a and b. Indeed, the wavelengths of major interest for their absorption detection were identified. If chlorophyll quantifications were achieved directly from reflectance spectra, for carotenoids the absorption bands did not allow good reflectance correlations. Nonetheless, thanks to the physiological relation of photosynthetic pigments, the chlorophyll/carotenoid ratio was used to estimate carotenoid content. Because their proportion changes during berry development, the index coefficients can be adapted in relation to the BBCH phenological stage. These indices demonstrated good correlations with the destructive quantifications. Also, the degradation intensity of the chlorophyll was different from that of the carotenoid during maturation, leading to a change in their absorption proportion throughout ripening. This finding allows suggesting that in white berries, the colour change during berry development is not related to the activation of a specific biosynthetic pathway, but is mostly the result of catabolic processes. Chardonnay and Riesling showed different susceptibility to sunburn. The results suggest that for each variety, the timing of leaf removal during the day is fundamental to reducing the appearance of brown color in the berry skin. In Chardonnay it would be better to avoid any leaf removal especially in pre-veraison, in the morning. Because Riesling was more susceptible during the afternoon, it would be recommendable to remove leaves, if necessary, during the early morning. The aims of the last two years (2014-2015) data collection were: (i) to evaluate phenolics in Riesling and Chardonnay berries in response to sunlight exposure under different irrigation regimes; (ii) to study the relation of water stress to sunburn appearance. The experiment was carried out in the Columbia Crest vineyards (Columbia Valley, Washington State, USA). Chardonnay and Riesling berries were collected from two different vineyards. Two different irrigation regimes were applied in both vineyards. Full irrigation (FI): vines were irrigated to replace 100% crop evapotranspiration, from fruit set to harvest, with no water stress imposed. Deficit irrigation (DI): vines were irrigated to maintain a moderate water stress (stem water potential (\uf059stem) at midday between -0.7 and -1 MPa) from fruit set to harvest. For compositional analysis two cluster exposures were considered: one exposed to direct sunlight (sun), and the other totally shaded from sunlight (shade). Skin flavonol, flavan3ol and proanthocyanidin content were analysed by HPLC methods. Total tannins were measured by spectrophotometer. Six temperature/light sensors per irrigation treatment were randomly installed on 3 sun and 3 shade bunches. In terms of absolute concentration in both varieties, several statistical tests indicate greater amount of variance accounted for by the effect exposure and phenological stages, and their interaction. No effect was due to the irrigation, in both varieties. Chardonnay had much higher flavanol concentration than Riesling. Chardonnay had much higher flavanols in the pre- veraison than during ripening. In Chardonnay the amount of monomers, dimers, trimers and polymers was greater in sun exposed berries than in shaded berries. Unlike in Chardonnay, in Riesling no flavan3ols monomers were detected by HPLC during the pre-veraison and veraison. In Riesling the amount of monomers, dimers and trimers was greater in sun exposed berries than in shaded berries. In both varieties flavonol concentrations were much higher in sun exposed berries than in shaded berries, with absolute much higher concentration in Chardonnay. Flavonols increased during ripening, especially in the sun in both Chardonnay and Riesling. Under similar light conditions the difference in temperature within the two irrigation treatments in the sun, could be due to the less vigorous canopy of DI plants compared with FI plants, which overall lead to greater cluster exposure, in both varieties. Nonetheless, the temperatures were always lower in FI and higher in DI, supporting the hypothesis of a possible no (or little) effect on flavonol biosynthesis. Shaded-bunch temperatures were always lower as compared to sun exposed ones, as direct solar heating did not occur in the shaded-conditions

Towards early hemolysis detection: a smartphone based approach

Os especialistas em diagnóstico in vitro (IVDs) têm confiado maioritariamente na inspeção visual (ótica) manual e, em segundo lugar, em sensores óticos ou câmaras embutidas ou dispositivos médicos incorporados que suportam o exame da qualidade da amostra na fase pré-analítica. Com o aumento dos volumes de amostras para serem processadas e dos respetivos dados complexos gerados por esse processamento, aquelas técnicas tornaram-se cada vez mais difíceis de utilizar, ou os respetivos resultados não ficam imediatamente disponíveis. Para superar as complexidades impostas por tais técnicas tradicionais, o aumento do uso de dispositivos móveis e algoritmos de processamento de imagem no setor de saúde abriu caminho para a constituição de novos casos de uso baseados em análises móveis de amostras, pois fornecem uma interação simples e intuitiva com objetos gráficos familiares que são mostrados no ecrã dos smartphones. As interfaces gráficas e as técnicas de interação suportadas por dispositivos móveis podem pois proporcionar ao especialista em IVD uma série de vantagens e valor agregado devido à maior familiaridade com estes dispositivos e à grande acessibilidade que evidenciam atualmente, tendo o potencial de facilitar as análises de amostras. No entanto, o uso sistemático de dispositivos móveis no setor da saúde encontra-se ainda numa fase muito incipiente, em particular na área de IVD. Nesta tese, propõe-se conceber e discutir a arquitetura, a conceção e a implementação de um protótipo de uma aplicação móvel para smartphone (designada por "HemoDetect") que implementa um conjunto sugerido de algoritmos, interfaces e técnicas de interação que foram desenvolvidos com o objetivo de contribuir para a compreensão de técnicas mais eficientes para ajudar a detetar a hemólise, um processo que designa a rotura de glóbulos vermelhos (eritrócitos) e libertação do respetivo conteúdo (citoplasma) para o fluído circundante (por exemplo, plasma sanguíneo), complementando-as com estatísticas e medições de laboratório, mostrando a utilização de um protótipo durante experiências, permitindo assim chegar-se a um conceito viável que permita apoiar eficazmente a deteção precoce de hemólise.In Vitro Diagnostics (IVDs) specialists have been firstly relying on manual visual (optical) inspection and, secondly, on optical sensors or cameras embedded or built-in medical devices which support the examination of sample quality in pre-analytical phase. With increasing sample processing volumes and their generated complex data, these techniques have become increasingly difficult or results are not readily available. In order to overcome the complexities posed by these traditional techniques, the increased usage of mobile devices and algorithms in the healthcare industry paves the way into shaping new use cases and discovery of mobile analysis of samples, as they provide a user-friendly and familiar interaction with objects displayed on their screens. The interfaces and interaction techniques rendered by mobile devices, bring, to the IVD specialist, a number of advantages and added value due to increased familiarity with the devices or their accessibility, which is made easier. However, they are at the beginning of their journey in the healthcare industry, in particular in the IVD and point-of-care areas. In this thesis, the proposal is to discover and discuss the architecture, design and implementation of a smartphone prototype app (called “HemoDetect”) with its algorithms, interfaces and interaction techniques which was developed to help detect hemolysis which represents the rupture of red blood cells (erythrocytes) and release of their contents (cytoplasm) into surrounding fluid (e.g. blood plasma), and complementing it with from-the-lab statistics and measurements showing its utilization during experiments, which ultimately may be a feasible concept that could support early hemolysis detection.Les spécialistes du diagnostic in vitro (DIV) se sont d'abord appuyés sur l'inspection visuelle (optique) manuelle et, ensuite, sur des capteurs optiques ou des caméras intégrées ou intégrées à des dispositifs médicaux qui facilitent l'examen de la qualité des échantillons en phase pré-analytique. Avec l'augmentation des volumes de traitement des échantillons et des données complexes générées, ces techniques sont devenues de plus en plus difficiles ou les résultats ne sont pas facilement disponibles. Afin de surmonter les complexités posées par ces techniques traditionnelles, l'utilisation croissante des appareils mobiles et des algorithmes dans le secteur de la santé ouvre la voie à la définition de nouveaux cas d'utilisation et à la découverte d'analyses d'échantillons mobiles, car ils fournissent une interaction conviviale et familière. avec des objets affichés sur leurs écrans. Les interfaces et les techniques d'interaction rendues par les appareils mobiles apportent au spécialiste des dispositifs de DIV un certain nombre d'avantages et de valeur ajoutée en raison d'une familiarisation accrue avec les appareils ou de leur accessibilité, ce qui est facilité. Cependant, ils sont au début de leur parcours dans le secteur de la santé, en particulier dans le domains des DIV et point-of-care. Dans cette thèse, la proposition est de découvrir et de discuter de l’architecture, de la conception et de la mise en oeuvre d’une application pour smartphone (appelée «HemoDetect») avec ses algorithmes, interfaces et techniques d’interaction, qui a été développée pour aider à détecter l’hémolyse qui représente une rupture des globules rouges (érythrocytes) et la libération de leur contenu (cytoplasme) dans le liquide environnant (par exemple, le plasma sanguin), en le complétant par des statistiques de laboratoire et des mesures montrant son utilisation au cours des expériences, ce qui pourrait finalement être un concept réalisable qui pourrait permettre une détection précoce de l'hémolyse