Value of Options in Airport Expansion - Example of AICM

http://www-sre.wu.ac.at/ersa/ersaconfs/ersa11/e110830aFinal00149.pdfInvestments decisions for airport capacity expansion are usually taken, either when demand exceeds the current capacity and the airport is working under congestion, or when current demand is expected to overcome current capacity sometime in the near future. In any case, decisions are taken taking into account forecasts of future demand. In many situations, deterministic analysis lead to a discouraging net present value (NPV) which in turn causes delays in the deciding process and eventually leads to further losses. This paper takes the Mexico City International Airport (AICM) as example, and performs an analysis of expansion investment, both in runways and terminals capacity, taking a perspective that is twofold: we take uncertainty of demand into account based on historical data of relevant parameters; we use flexibility in design by incorporating options in project, for both new runways and new terminal. Using a binomial lattice model, we calculate the value of options, perform sensitivity analysis and determine the expected statistical distribution of NPV. We obtain significant differences when compared with the deterministic perspective, and illustrate by example how real options and flexible design may dramatically improve the attractiveness of an investment decision

Proposta de calibração da técnica LIBS para minérios de sulfuretos metálicos: um exemplo para a Mina de Aljustrel

Neste trabalho estuda-se a capacidade da técnica laser induced-breakdown spectroscopy (LIBS), para a quantificação expedita das concentrações de alguns elementos químicos de interesse mineiro, em minérios de sulfuretos metálicos. O LIBS é uma técnica de espectroscopia de emissão atómica, onde a incidência de um laser intenso na amostra gera uma nuvem de plasma. Os átomos e iões desprendidos da amostra e vaporizados produzem um espectro e assim, a análise dos picos de radiação emitida permite a identificação da presença dos elementos químicos e a sua quantidade na amostra. Os espectros resultantes são muito sensíveis à matriz, assim cada matriz deve ser calibrada separadamente para que os resultados possam ser utilizados com confiança. Esta técnica é uma alternativa à tradicional fluorescência de raios X (XRF), que embora quantifique os elementos químicos de interesse por assinatura é mais morosa e expõe o utilizador a pequenas doses de radiação. Neste trabalho foram utilizados dois conjuntos de amostras de sulfuretos metálicos de cobre e zinco da Mina de Aljustrel, o primeiro foi utilizado para treino e calibração e o segundo foi utilizado para validação. As amostras referem-se a minérios maciços e de stockwork, com teores de cobre e zinco representativos do intervalo de valores que ocorrem na mina. Para a calibração, os valores dos picos de intensidade dos espectros do LIBS foram comparados com os teores fornecidos pelo laboratório da Mina de Aljustrel das mesmas amostras. A calibração foi feita para cada elemento em separado, tendo sido selecionados os comprimentos de onda da Base de Dados NIST e LIBS-info, assim como mais alguns comprimentos de onda onde se verificaram as melhores correlações. Depois de se conseguir a melhor calibração para cada elemento com as amostras de treino, numa segunda fase aplicaram-se as calibrações ao segundo conjunto de amostras, tendo-se quantificado dos erros de previsão. Os resultados de R2 ficaram sempre acima de 0,85 o que demonstra que a calibração é eficaz para as matrizes testadas. Fica assim demonstrado, que os equipamentos portáteis de tipo LIBS, como o que foi utilizado neste estudo, constituem uma mais valia para a indústria extrativa, podendo ser utilizados nas várias fases do processo produtivo, desde a prospeção nas frentes, análise de sondagens e até ao processamento dos minérios.In this work, the ability of the laser induced-breakdown spectroscopy (LIBS) technique to quantify the concentrations of some chemical elements of mining interest in metal sulphide ores is studied. LIBS is an atomic emission spectroscopic technique, where the incidence of an intense laser in the sample generates a plasma. The laser makes the atoms and ions vaporized from the sample produce a spectrum, so the analysis of the emitted radiation peaks allows the identification of the presence of the chemical elements and their quantity in the sample. The results of the spectra are very sensitive to the matrix, so each matrix must be calibrated separately so that the results can be used with confidence. This technique is an alternative to the traditional X-ray fluorescence (XRF), which although it quantifies the chemical elements of interest by fingerprints it is more time consuming and exposes the user to small doses of radiation. In this work, two sets of samples of copper and zinc sulphides ores from the Aljustrel Mine were used, the first was used for training and calibration and the second was used for validation. The samples refer to massive and stockwork ores, with copper and zinc contents representative of the range of values that occur in the mine. For calibration, the peaks values spectra of intensity registered by the LIBS were compared with the levels provided by the Aljustrel Mine laboratory for the same samples. The calibration was done for each element separately, having been selected the wavelengths of the NIST Database as well as some more peak wavelengths where the best correlations were found. After achieving the best calibration for each element with the training samples, in a second phase the calibrations were applied to the second set of samples, and the forecasting errors were iv quantified. The R2 values were always above 0,85, which shows that the calibration is very effective for the tested matrices. It is thus demonstrated that portable LIBS-type equipment, such as the one used in this study, constitutes an added-value for the mining industry towards digitalization, and can be used in the various stages of the production process, from development tunnels and shafts, cores drilling and mineral processing facilities

Preparation of biopolymer-drug formulations for cancer drug delivery

Mannans are highly water-soluble mannose heteropolymers produced by a number of organisms, including yeasts. Polyhydroxyalkanoates (PHAs) are aliphatic polyesters produced by numerous bacteria as a carbon and energy source, with interesting thermal and mechanical properties. The main objective of this thesis was to prepare different polymeric structures base on mannans and PHAs for use in the pharmaceutical and biomedical areas. Mannans were produced by Komagataella pastoris using glycerol as carbon source, extracted with a heat-alkali treatment and purified using dialysis. PHAs were produced by mixed cultures using fermented fruit pulp waste, extracted using chloroform or hypochlorite and purified in ethanol. A successful deproteinization and an unsuccessful phosphorylation procedure was performed in mannans. The results show a decrease in protein content of 69.49 ± 0.44 % and a decrease in phosphate content of 60.45 ± 1.23 %, respectively. Mannans were tested in normal fibroblasts, HCT116 and A2780 cell lines for their cytotoxicity, by MTS assay, and no cytotoxicity was discovered. They were then used to prepare gel structures, and gelled using di- and tri-valent cations of iron and copper at low temperature (4 ⁰C) and alkaline pH. Gel particles were obtained in the above conditions and tested for their stability in water. Particles made using tri-valent iron were found the most stable. Mannans were also used to produce films. Films were obtained from i) mannans in water dried at 30 ⁰C or freeze dried, ii) from the previously produced films (30 ⁰C) and then coated with iron, at neutral pH or followed by immersion in an alkaline solution and, iii) from gel beads dried at 30 ⁰C or freeze dried. Films were tested for cell adhesion in vitro using normal fibroblasts, but no positive results were found. PHAs with different HV ratios were used to produce films, pure and blended with mannans, using chloroform as solvent by a solvent casting method. The produced films were tested for cell adhesion in vitro, using fibroblasts and MCF7-GFP. Pure PHA films were deemed good matrices for this application with cells adherent to their surface, whereas blend matrices failed in this regard. Some pure PHA matrices were then tested for their cytotoxicity using MCF7-GFP, and with the exception of co-polymer PHBHV with HV content of 18 % (extracted with hypochlorite), they were found to be non-cytotoxic, rendering them useful for biomedical applications such as wound dressing or drug delivery

Algebric Thinking manifestations on geometric patterns investigation

O presente trabalho expõe os dados oriundos de resoluções de tarefas exploratório-investigativas de Álgebra, objetivando identificar as manifestações do caracterizador do pensamento algébrico “perceber e tentar expressar regularidades ou invariâncias”, de acordo com Fiorentini, Fernandes e Cristóvão (2005). As atividades que foram realizadas por estudantes do 8º ano do ensino fundamental de uma escola estadual pelotense abordavam sequências com padrões definidos pelas variáveis: forma geométrica, posição e cor. Caracterizamos as manifestações do pensamento algébrico dos participantes a partir de dois tipos de resoluções: um com a identificação e expressão do padrão geométrico, variando as formas de representação, e outro em que, ou não houve identificação da regularidade, ou houve a identificação do padrão sem, entretanto, expressá-lo.The present paper exposes the data from the resolutions of Algebra exploratory-investigative tasks, aiming to identify the manifestations of the characteristic of algebraic thinking “perceiving and trying to express regularities or invariances” according to Fiorentini, Fernandes and Cristóvão (2005). The activities, which were carried out by students in the 8th year of elementary school at a state public school in Pelotas, addressed sequences with patterns defined by the variables geometric shape, position and color. We characterized the manifestations of the algebraic thinking of the participants from two resolutions types: one with the geometric pattern identification and expression, varying the representation forms, and another in which, either there was no regularity identification, or there was standard identification without, however, expressing it

PEDOT:PSS-coated polybenzimidazole electroconductive nanofibers for biomedical applications

Bioelectricity drives several processes in the human body. The development of new materials that can deliver electrical stimuli is gaining increasing attention in the field of tissue engineering. In this work, novel, highly electrically conductive nanofibers made of poly [2,20 - m-(phenylene)-5,50 -bibenzimidazole] (PBI) have been manufactured by electrospinning and then coated with cross-linked poly (3,4-ethylenedioxythiophene) doped with poly (styrene sulfonic acid) (PEDOT:PSS) by spin coating or dip coating. These scaffolds have been characterized by scanning electron microscopy (SEM) imaging and attenuated total reflectance Fourier-transform infrared (ATR-FTIR) spectroscopy. The electrical conductivity was measured by the four-probe method at values of 28.3 S·m−1 for spin coated fibers and 147 S·m−1 for dip coated samples, which correspond, respectively, to an increase of about 105 and 106 times in relation to the electrical conductivity of PBI fibers. Human bone marrow-derived mesenchymal stromal cells (hBM-MSCs) cultured on the produced scaffolds for one week showed high viability, typical morphology and proliferative capacity, as demonstrated by calcein fluorescence staining, 40 ,6-diamidino-2-phenylindole (DAPI)/Phalloidin staining and MTT [3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyl tetrazolium bromide] assay. Therefore, all fiber samples demonstrated biocompatibility. Overall, our findings highlight the great potential of PEDOT:PSS-coated PBI electrospun scaffolds for a wide variety of biomedical applications, including their use as reliable in vitro models to study pathologies and the development of strategies for the regeneration of electroactive tissues or in the design of new electrodes for in vivo electrical stimulation protocols.info:eu-repo/semantics/publishedVersio

Perfil energético e hormonal de ovelhas Santa Inês do terço médio da gestação ao pós-parto

No período periparto ocorrem importantes adequações fisiológicas que, se não forem efetivas predispõem a fêmea a enfermidades metabólicas. O conhecimento desta adaptação é relevante para que sejam implementadas, precocemente, medidas preventivas a poupar perdas produtivas. Com este objetivo foi avaliado o perfil energético e hormonal de ovelhas Santa Inês durante a gestação e puerpério. Foram utilizadas 10 ovelhas não gestantes (G0), 10 gestantes de um (G1) e 14 gestantes de dois e três fetos (G2). Foram avaliadas concentrações plasmáticas de glicose, ácidos graxos não esterificados (AGNE), betahidroxibutirato (BHB), e as concentrações séricas de insulina, glucagon, cortisol, triiodotironina (T3) e tiroxina (T4) a partir do 88º dia de gestação até o 28º dia pós-parto. No terço final de gestação, ovelhas gestantes apresentaram maiores concentrações de AGNE, T3 e T4 que as ovelhas não gestantes. No momento do parto foram observadas maiores concentrações de glicose, AGNE e T3 para todas as ovelhas gestantes em relação às não gestantes. Não houve diferença entre as ovelhas gestantes de um, dois ou três fetos. As diferenças observadas ocorreram apenas entre ovelhas gestantes e as vazias. Portanto, quando há adequada adaptação neste período de elevado desafio metabólico, os parâmetros bioquímicos aqui considerados independem do número de fetos gestados e podem ser considerados como valores de referência para ovelhas gestantes de um feto ou mais fetos do terço médio de gestação ao primeiro mês pós-parto

Strong Interaction Physics at the Luminosity Frontier with 22 GeV Electrons at Jefferson Lab

This document presents the initial scientific case for upgrading the Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab (JLab) to 22 GeV. It is the result of a community effort, incorporating insights from a series of workshops conducted between March 2022 and April 2023. With a track record of over 25 years in delivering the world's most intense and precise multi-GeV electron beams, CEBAF's potential for a higher energy upgrade presents a unique opportunity for an innovative nuclear physics program, which seamlessly integrates a rich historical background with a promising future. The proposed physics program encompass a diverse range of investigations centered around the nonperturbative dynamics inherent in hadron structure and the exploration of strongly interacting systems. It builds upon the exceptional capabilities of CEBAF in high-luminosity operations, the availability of existing or planned Hall equipment, and recent advancements in accelerator technology. The proposed program cover various scientific topics, including Hadron Spectroscopy, Partonic Structure and Spin, Hadronization and Transverse Momentum, Spatial Structure, Mechanical Properties, Form Factors and Emergent Hadron Mass, Hadron-Quark Transition, and Nuclear Dynamics at Extreme Conditions, as well as QCD Confinement and Fundamental Symmetries. Each topic highlights the key measurements achievable at a 22 GeV CEBAF accelerator. Furthermore, this document outlines the significant physics outcomes and unique aspects of these programs that distinguish them from other existing or planned facilities. In summary, this document provides an exciting rationale for the energy upgrade of CEBAF to 22 GeV, outlining the transformative scientific potential that lies within reach, and the remarkable opportunities it offers for advancing our understanding of hadron physics and related fundamental phenomena.Comment: Updates to the list of authors; Preprint number changed from theory to experiment; Updates to sections 4 and 6, including additional figure

Designing Electrical Stimulation Platforms for Neural Cell Cultivation Using Poly(aniline): Camphorsulfonic Acid

Electrical stimulation is a powerful strategy to improve the differentiation of neural stem cells into neurons. Such an approach can be implemented, in association with biomaterials and nanotechnology, for the development of new therapies for neurological diseases, including direct cell transplantation and the development of platforms for drug screening and disease progression evaluation. Poly(aniline):camphorsulfonic acid (PANI:CSA) is one of the most well-studied electroconductive polymers, capable of directing an externally applied electrical field to neural cells in culture. There are several examples in the literature on the development of PANI:CSA-based scaffolds and platforms for electrical stimulation, but no review has examined the fundamentals and physico-chemical determinants of PANI:CSA for the design of platforms for electrical stimulation. This review evaluates the current literature regarding the application of electrical stimulation to neural cells, specifically reviewing: (1) the fundamentals of bioelectricity and electrical stimulation; (2) the use of PANI:CSA-based systems for electrical stimulation of cell cultures; and (3) the development of scaffolds and setups to support the electrical stimulation of cells. Throughout this work, we critically evaluate the revised literature and provide a steppingstone for the clinical application of the electrical stimulation of cells using electroconductive PANI:CSA platforms/scaffolds

Perfil energético e hormonal de ovelhas Santa Inês do terço médio da gestação ao pós-parto

No período periparto ocorrem importantes adequações fisiológicas que, se não forem efetivas predispõem a fêmea a enfermidades metabólicas. O conhecimento desta adaptação é relevante para que sejam implementadas, precocemente, medidas preventivas a poupar perdas produtivas. Com este objetivo foi avaliado o perfil energético e hormonal de ovelhas Santa Inês durante a gestação e puerpério. Foram utilizadas 10 ovelhas não gestantes (G0), 10 gestantes de um (G1) e 14 gestantes de dois e três fetos (G2). Foram avaliadas concentrações plasmáticas de glicose, ácidos graxos não esterificados (AGNE), betahidroxibutirato (BHB), e as concentrações séricas de insulina, glucagon, cortisol, triiodotironina (T3) e tiroxina (T4) a partir do 88º dia de gestação até o 28º dia pós-parto. No terço final de gestação, ovelhas gestantes apresentaram maiores concentrações de AGNE, T3 e T4 que as ovelhas não gestantes. No momento do parto foram observadas maiores concentrações de glicose, AGNE e T3 para todas as ovelhas gestantes em relação às não gestantes. Não houve diferença entre as ovelhas gestantes de um, dois ou três fetos. As diferenças observadas ocorreram apenas entre ovelhas gestantes e as vazias. Portanto, quando há adequada adaptação neste período de elevado desafio metabólico, os parâmetros bioquímicos aqui considerados independem do número de fetos gestados e podem ser considerados como valores de referência para ovelhas gestantes de um feto ou mais fetos do terço médio de gestação ao primeiro mês pós-parto