Droplet oscillations in high gradient magnetic field

In high intensity and high gradient magnetic fields the volumetric force on diamagnetic material, such as water, leads to conditions very similar to microgravity in a terrestrial laboratory. In principle, this opens the possibility to determine material properties of liquid samples without wall contact, even for electrically non-conducting materials. In contrast, AC field levitation is used for conductors, but then terrestrial conditions lead to turbulent flow driven by Lorentz forces. DC field damping of the flow is feasible and indeed practiced to allow property measurements. However, the AC/DC field combination acts preferentially on certain oscillation modes and leads to a shift in the droplet oscillation spectrum.What is the cause? A nonlinear spectral numerical model is presented, to address these problems

Droplet oscillations in high gradient static magnetic field

In high intensity and high gradient magnetic fields the volumetric force on diamagnetic material, such as water, leads to conditions very similar to microgravity in a terrestrial laboratory. In principle, this opens the possibility to determine material properties of liquid samples without wall contact, even for electrically non-conducting materials. In contrast, AC field levitation is used for conductors, but then terrestrial conditions lead to turbulent flow driven by Lorentz forces. DC field damping of the flow is feasible and indeed practiced to allow property measurements. However, the AC/DC field combination acts preferentially on certain oscillation modes and leads to a shift in the droplet oscillation spectrum.What is the cause? A nonlinear spectral numerical model is presented, to address these problems.

Valorização de resíduos carbonosos de gasificação como precursores de materiais para adsorção de poluentes em fase aquosa

Tese de doutoramento, Energia e Ambiente (Energia e Desenvolvimento Sustentável), Universidade de Lisboa, Faculdade de Ciências, 2014

Conceção e construção de um simulador de controlo de vibrações

Trabalho Final de Mestrado para obtenção do grau de Mestre em Engenharia Mecânica

Desenvolvimento e aplicação de um biossensor para monitorização de creatinina, um biomarcador associado a doenças emergentes

Este trabalho descreve o desenvolvimento de um material sensor para creatinina por impressão molecular em estrutura polimérica (MIP) e a sua aplicação no desenvolvimento de um dispositivo de natureza potenciométrica para a determinação da molécula alvo em fluidos biológicos. A creatinina é um dos biomarcadores mais utilizados no acompanhamento da doença renal, já que é um bom indicador da taxa de filtração glomerular (TFG). Os materiais biomiméticos desenhados para interação com a creatinina foram obtidos por polimerização radicalar, recorrendo a monómeros de ácido metacríclico ou de vinilpiridina e a um agente de reticulação apropriado. De modo a aferir o efeito da impressão da creatinina na resposta dos materiais MIP à sua presença, foram também preparados e avaliados materiais de controlo, obtidos sem impressão molecular (NIP). O controlo da constituição química destes materiais, incluindo a extração da molécula impressa, foi realizado por Espectroscopia de Raman e de Infravermelho com Transformada de Fourrier. A afinidade de ligação entre estes materiais e a creatinina foi também avaliada com base em estudos cinéticos. Todos os materiais descritos foram integrados em membranas selectivas de elétrodos seletivos de ião, preparadas sem ou com aditivo iónico lipófilo, de carga negativa ou positiva. A avaliação das características gerais de funcionamento destes elétrodos, em meios de composição e pH diferentes, indicaram que as membranas com materiais impressos e aditivo aniónico eram as únicas com utilidade analítica. Os melhores resultados foram obtidos em solução tampão Piperazine-N,N′-bis(2- ethanesulfonic acid), PIPES, de pH 2,8, condição que permitiu obter uma resposta quasi-Nernstiana, a partir de 1,6×10-5 mol L-1. Estes elétrodos demonstraram ainda uma boa selectividade ao apresentaram uma resposta preferencial para a creatinina quando na presença de ureia, carnitina, glucose, ácido ascórbico, albumina, cloreto de cálcio, cloreto de potássio, cloreto de sódio e sulfato de magnésio. Os elétrodos foram ainda aplicados com sucesso na análise de amostras sintéticas de urina, quando os materiais sensores eram baseados em ácido metacrilico, e soro, quando os materiais sensores utilizados eram baseados em vinilpiridina.

Novel Prostate Specific Antigen plastic antibody designed withcharged binding sites for an improved protein binding and itsapplication in a biosensor of potentiometric transduction

This work shows that the synthesis of protein plastic antibodies tailored with selected charged monomersaround the binding site enhances protein binding. These charged receptor sites are placed over a neutralpolymeric matrix, thus inducing a suitable orientation the protein reception to its site. This is confirmed bypreparing control materials with neutral monomers and also with non-imprinted template. This concepthas been applied here to Prostate Specific Antigen (PSA), the protein of choice for screening prostate can-cer throughout the population, with serum levels >10 ng/mL pointing out a high probability of associatedcancer.Protein Imprinted Materials with charged binding sites (C/PIM) have been produced by surfaceimprinting over graphene layers to which the protein was first covalently attached. Vinylben-zyl(trimethylammonium chloride) and vinyl benzoate were introduced as charged monomers labellingthe binding site and were allowed to self-organize around the protein. The subsequent polymerizationwas made by radical polymerization of vinylbenzene. Neutral PIM (N/PIM) prepared without orientedcharges and non imprinted materials (NIM) obtained without template were used as controls.These materials were used to develop simple and inexpensive potentiometric sensor for PSA. Theywere included as ionophores in plasticized PVC membranes, and tested over electrodes of solid or liq-uid conductive contacts, made of conductive carbon over a syringe or of inner reference solution overmicropipette tips. The electrodes with charged monomers showed a more stable and sensitive response,with an average slope of -44.2 mV/decade and a detection limit of 5.8 × 10−11mol/L (2 ng/mL). The cor-responding non-imprinted sensors showed lower sensitivity, with average slopes of -24.8 mV/decade.The best sensors were successfully applied to the analysis of serum, with recoveries ranging from 96.9to 106.1% and relative errors of 6.8%.

Smart Plastic Antibody Material (SPAM) tailored on disposable screen printed electrodes for protein recognition: application to Myoglobin detection

This work introduces two major changes to the conventional protocol for designing plastic antibodies: (i) the imprinted sites were created with charged monomers while the surrounding environment was tailored using neutral material; and (ii) the protein was removed from its imprinted site by means of a protease, aiming at preserving the polymeric network of the plastic antibody. To our knowledge, these approaches were never presented before and the resulting material was named here as smart plastic antibody material (SPAM). As proof of concept, SPAM was tailored on top of disposable gold-screen printed electrodes (Au-SPE), following a bottom-up approach, for targeting myoglobin (Myo) in a point-of-care context. The existence of imprinted sites was checked by comparing a SPAM modified surface to a negative control, consisting of similar material where the template was omitted from the procedure and called non-imprinted materials (NIMs). All stages of the creation of the SPAM and NIM on the Au layer were followed by both electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). AFM imaging was also performed to characterize the topography of the surface. There are two major reasons supporting the fact that plastic antibodies were effectively designed by the above approach: (i) they were visualized for the first time by AFM, being present only in the SPAM network; and (ii) only the SPAM material was able to rebind to the target protein and produce a linear electrical response against EIS and square wave voltammetry (SWV) assays, with NIMs showing a similar-to-random behavior. The SPAM/Au-SPE devices displayed linear responses to Myo in EIS and SWV assays down to 3.5 μg/mL and 0.58 μg/mL, respectively, with detection limits of 1.5 and 0.28 μg/mL. SPAM materials also showed negligible interference from troponin T (TnT), bovine serum albumin (BSA) and urea under SWV assays, showing promising results for point-of-care applications when applied to spiked biological fluids.

Label-free Detection of Microcystin-LR in Waters Using Real-Time Potentiometric Biosensors Based on Single-Walled Carbon Nanotubes Imprinted Polymers

Microcystin-LR (MC-LR) is a dangerous toxin found in environmental waters, quantified by high performance liquid chromatography and/or enzyme-linked immunosorbent assays. Quick, low cost and on-site analysis is thus required to ensure human safety and wide screening programs. This work proposes label-free potentiometric sensors made of solid-contact electrodes coated with a surface imprinted polymer on the surface of Multi-Walled Carbon NanoTubes (CNTs) incorporated in a polyvinyl chloride membrane. The imprinting effect was checked by using non-imprinted materials. The MC-LR sensitive sensors were evaluated, characterized and applied successfully in spiked environmental waters. The presented method offered the advantages of low cost, portability, easy operation and suitability for adaptation to flow methods.

Biopulping of Paddy Straw by Pleurotus eous

Biopulping being less energy intensive, inexpensive and causing lesser pollution, can be a viable alternative to chemical and mechanical pulping in paper and pulp industry. In view of shrinking forest reserves, agricultural residues are considered as an alternative raw material for making paper and board. By suitable treatment agriwaste can be converted into substrate for mushroom cultivation. Mushrooms of Pleurotus sp. can preferentially remove lignin from agriwaste with limited degradation to cellulose. The present study examines utilization of Pleurotus eous for biopulping of paddy straw by solid substrate fermentation. SMS, the mushroom growing medium that results from cultivation process, is a good source of fibre and can be pulped easily. Ligninases present in SMS were able to reduce lignin content to nearly half the initial amount by 21st day of cultivation. Highest cellulose content (% dry weight) was observed on 21st day, while cellulase production commenced from 28th day of cultivation. SEM images revealed that SMS fibres are still associated with non-cellulosic materials when compared to chemically (20% w/v NaOH) extracted fibres.

Classification of recycled sands and their applications as fine aggregates for concrete and bituminous mixtures

As a result of the drive towards waste-poor world and reserving the non-renewable materials, recycling the construction and demolition materials become very essential. Now reuse of the recycled concrete aggregate more than 4 mm in producing new concrete is allowed but with natural sand a fine aggregate while. While the sand portion that represent about 30\% to 60\% of the crushed demolition materials is disposed off. To perform this research, recycled concrete sand was produced in the laboratory while nine recycled sands produced from construction and demolitions materials and two sands from natural crushed limestone were delivered from three plants. Ten concrete mix designs representing the concrete exposition classes XC1, XC2, XF3 and XF4 according to European standard EN 206 were produced with partial and full replacement of natural sand by the different recycled sands. Bituminous mixtures achieving the requirements of base courses according to Germany standards and both base and binder courses according to Egyptian standards were produced with the recycled sands as a substitution to the natural sands. The mechanical properties and durability of concrete produced with the different recycled sands were investigated and analyzed. Also the volumetric analysis and Marshall test were performed hot bituminous mixtures produced with the recycled sands. According to the effect of replacement the natural sand by the different recycled sands on the concrete compressive strength and durability, the recycled sands were classified into three groups. The maximum allowable recycled sand that can be used in the different concrete exposition class was determined for each group. For the asphalt concrete mixes all the investigated recycled sands can be used in mixes for base and binder courses up to 21\% of the total aggregate mass.

Exploring conference proceedings contribution to marketing knowledge : some initial evidence and directions for the future

This paper examines the degree to which works appearing in JM, JMR and JCR cite materials other than academic journals. The results suggest the number of citations to proceedings has fallen since earlier works (Anderson and Haley, 1984). This may be explained by the increased number of marketing related journals available in hard copy and through electronic databases. Citations of non-journal materials within marketing literature are however, higher than were found by Armstrong and Pagell (2003) in the forecasting literature. Some suggestions for future research are provided.

Applications of electrospun nanofibers

Polymeric nanofiber non-woven materials produced by electrospinning have extremely high surface-to-mass (or volume) ratio and a porous structure with excellent pore-interconnectivity. These characteristics plus the functionalities and surface chemistry of the polymer itself impart the nanofibers with desirable properties for a range of advanced applications. This review summarizes the recent progress in electrospun nanofibers, with an emphasis on their applications.

The unstable print: Material challenges in printmaking and the moving image

The past few years have seen an emergence of printmakers motivated by moving-image technology to use print as performative creative practice; in film and animation, as installation and in various processes of thinking and production. Notions of movement and change that could be said to identify much of our contemporary world reflect the interests of a number of printmakers who utilize printmaking characteristics of multiplicity and reproduction by integrating the digital and the handmade within the moving-image. There seems to be a restlessness by some artists who wish to explore an unbounded, experimental approach to printmaking; perhaps it is a natural progression for printmakers to relate their processes of thinking and production to concepts of frame-by-frame production – to additive and subtractive methods, multiple imagery and the reproduced or copy. But what happens when printmaking that has entered the realm of multimedia technology returns to the physical, material print? This paper presents and discusses printmaking as moving image, and in particular the practice of printmaking that utilizes the copy and multiplicity while exploiting qualities of change through, for example, organic non-archival materials. Drawing from my own print projects and practice as well as the work of other Australian printmakers, the paper asks: can the physical print convincingly perform, not only represent, movement and change as analog experience through its materiality, and how is it to be valued within printmaking conventions concerned with longevity and permanence?