Design and testing of a microvalve capable of precisely controlling low fluidic flow rates

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2011.Cataloged from PDF version of thesis.Includes bibliographical references (p. 48).Development of the design, manufacture, and testing for a gas flow regulating microvalve is presented herein. The microvalve project served as a test bed for new micromachining techniques and for exploration of MEMS devices made from non-silicon materials. We developed and tested a novel microvalve utilizing a passive mechanical membrane that allows for accurate flow rate control over a wide range of inlet pressures, requiring power only to adjust the flow rate. Design considerations and functional analysis of a microvalve system are discussed, and manufacturing techniques analyzed. The design was verified by comparing the prototyped system to a commercially available mini ball valve. The valves were run through full actuation at varying pressures and the resulting flow was observed and characterized. At 0.69 MPa, the flexure valve prototype was shown to allow adjustments in flow between 1.0* 10-6 and 2.0* 106 m3/s over the period of about 8 seconds, allowing for a precision adjustment of flow not available in other valves. The experiment demonstrates that the new microvalve offers significant advantages in terms of a wider range of flow rate adjustment available within the operating pressure regime.by Cody R. Daniel and Toomas R. Sepp.S.B

Hábitos de sono e performance académica: estudo comparativo entre Estónia e Portugal

Actualmente, na nossa sociedade, muitas das actividades diárias têm prioridade sobre o sono. A privação do sono em estudantes tem sido documentada em variados países e o problema reside no conflito entre a necessidade física e psicológica, dos estudantes, de dormir e os seus horários. Esta privação do sono é, muitas das vezes, relacionada com a diminuição do humor e do rendimento académico. No intuito de combater estes problemas, alguns estudantes recorrem ao uso de fármacos ou substâncias com vista a melhorar a sua qualidade de vida e o seu rendimento escolar. O objectivo deste estudo é (1) avaliar a qualidade de sono dos estudantes universitários, (2) avaliar a percentagem de estudantes que consomem fármacos ou substâncias para modificar o seu sono e (3) comparar os resultados entre duas escolas de saúde, Escola Superior de Tecnologia da Saúde do Porto, Portugal (ESTSP) e a Tallinn Health Care College, Estónia (THCC)

Crenças, aceitação e atitudes dos utentes perante os medicamentos genéricos: um estudo comparativo entre Portugal e Estónia

Medicamento genérico (MG) é definido como uma fiel imitação de um medicamento original, terapeuticamente equivalente apresentando a mesma forma farmacêutica, composição qualitativa e quantitativa destinado a ser intercambiável com o produto original. Os MGs só podem ser comercializados depois de todas as patentes e certificados complementares de protecção (SPCs) que cobrem o produto original terem expirado. O papel dos MGs tem sido providenciar medicamentos essenciais que são de boa qualidade e de preço acessível em toda a União Europeia e o seu uso aumentou a acessibilidade dos pacientes e proporcionou uma poupança económica significativa para os sistemas de saúde. À medida que as despesas totais em cuidados de saúde têm vindo a aumentar e a maioria dessas despesas é composta de custos fixos (nomeadamente os serviços hospitalares), a indústria farmacêutica tem sido um objectivo de poupança em todos os países da Europa, que têm reformulado os seus sistemas nacionais de saúde de modo a responder ao rápido crescimento dos gastos em saúde. Os governos preocupados com o aumento do custo de produtos farmacêuticos dentro dos seus orçamentos nacionais de saúde, estão a esforçar-se para promover a utilização de genéricos em relação aos produtos originais de preço mais elevado. Portugal e Estónia são dois países pertencentes à União Europeia. Existem algumas diferenças no sector da saúde entre os dois países, especialmente no que concerne a medicamentos, seus preços e reembolso pelos sistemas de seguro obrigatório de saúde e serviços nacionais de saúde, no entanto apresentam em comum a preocupação com o custo dos medicamentos, incentivando o uso de MGs. Actualmente a Estónia apresenta uma quota de mercado de MGs superior a Portugal, que ocupa uma posição inferior à média Europeia. À medida que os sistemas governamentais vão incentivando o uso de MGs e o seu consumo vai aumentando é importante perceber as opiniões que os consumidores têm acerca destes medicamentos. Este estudo teve como objectivo avaliar a aceitação e as crenças dos utentes sobre MGs em relação aos medicamentos de marca (MM), comparando resultados entre Portugal e Estónia

COST 733 - WG4: Applications of weather type classification

The main objective of the COST Action 733 is to achieve a general numerical method for assessing, comparing and classifying typical weather situations in the European regions. To accomplish this goal, different workgroups are established, each with their specific aims: WG1: Existing methods and applications (finished); WG2: Implementation and development of weather types classification methods; WG3: Comparison of selected weather types classifications; WG4: Testing methods for various applications. The main task of Workgroup 4 (WG4) in COST 733 implies the testing of the selected weather type methods for various classifications. In more detail, WG4 focuses on the following topics:• Selection of dedicated applications (using results from WG1), • Performance of the selected applications using available weather types provided by WG2, • Intercomparison of the application results as a results of different methods • Final assessment of the results and uncertainties, • Presentation and release of results to the other WGs and external interested • Recommend specifications for a new (common) method WG2 Introduction In order to address these specific aims, various applications are selected and WG4 is divided in subgroups accordingly: 1.Air quality 2. Hydrology (& Climatological mapping) 3. Forest fires 4. Climate change and variability 5. Risks and hazards Simultaneously, the special attention is paid to the several wide topics concerning some other COST Actions such as: phenology (COST725), biometeorology (COST730), agriculture (COST 734) and mesoscale modelling and air pollution (COST728). Sub-groups are established to find advantages and disadvantages of different classification methods for different applications. Focus is given to data requirements, spatial and temporal scale, domain area, specifi

Probing scalar particle and unparticle couplings in e+ e- -> t tbar with transversely polarized beams

In searching for indications of new physics scalar particle and unparticle couplings in e^+ e^- \to t\bar t, we consider the role of transversely polarized initial beams at e^+ e^- colliders. By using a general relativistic spin density matrix formalism for describing the particles spin states, we find analytical expressions for the squared amplitude of the process with t or \bar t polarization measured, including the anomalous coupling contributions. Thanks to the transversely polarized initial beams these contributions are first order anomalous coupling corrections to the Standard Model (SM) contributions. We present and analyse the main features of the SM and anomalous coupling contributions. We show how differences between SM and anomalous coupling contributions provide means to search for anomalous coupling manifestations at future e^+ e^- linear colliders.Comment: 28 pages in LaTeX, including 7 encapsulated PostScript figures, published versio

Adsorption of CO on a Platinum (111) surface - a study within a four-component relativistic density functional approach

We report on results of a theoretical study of the adsorption process of a single carbon oxide molecule on a Platinum (111) surface. A four-component relativistic density functional method was applied to account for a proper description of the strong relativistic effects. A limited number of atoms in the framework of a cluster approach is used to describe the surface. Different adsorption sites are investigated. We found that CO is preferably adsorbed at the top position.Comment: 23 Pages with 4 figure

Liver-Targeting of Interferon-Alpha with Tissue-Specific Domain Antibodies

PMCID: PMC3581439This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Assessing the role of EO in biodiversity monitoring: options for integrating in-situ observations with EO within the context of the EBONE concept

The European Biodiversity Observation Network (EBONE) is a European contribution on terrestrial monitoring to GEO BON, the Group on Earth Observations Biodiversity Observation Network. EBONE’s aims are to develop a system of biodiversity observation at regional, national and European levels by assessing existing approaches in terms of their validity and applicability starting in Europe, then expanding to regions in Africa. The objective of EBONE is to deliver: 1. A sound scientific basis for the production of statistical estimates of stock and change of key indicators; 2. The development of a system for estimating past changes and forecasting and testing policy options and management strategies for threatened ecosystems and species; 3. A proposal for a cost-effective biodiversity monitoring system. There is a consensus that Earth Observation (EO) has a role to play in monitoring biodiversity. With its capacity to observe detailed spatial patterns and variability across large areas at regular intervals, our instinct suggests that EO could deliver the type of spatial and temporal coverage that is beyond reach with in-situ efforts. Furthermore, when considering the emerging networks of in-situ observations, the prospect of enhancing the quality of the information whilst reducing cost through integration is compelling. This report gives a realistic assessment of the role of EO in biodiversity monitoring and the options for integrating in-situ observations with EO within the context of the EBONE concept (cfr. EBONE-ID1.4). The assessment is mainly based on a set of targeted pilot studies. Building on this assessment, the report then presents a series of recommendations on the best options for using EO in an effective, consistent and sustainable biodiversity monitoring scheme. The issues that we faced were many: 1. Integration can be interpreted in different ways. One possible interpretation is: the combined use of independent data sets to deliver a different but improved data set; another is: the use of one data set to complement another dataset. 2. The targeted improvement will vary with stakeholder group: some will seek for more efficiency, others for more reliable estimates (accuracy and/or precision); others for more detail in space and/or time or more of everything. 3. Integration requires a link between the datasets (EO and in-situ). The strength of the link between reflected electromagnetic radiation and the habitats and their biodiversity observed in-situ is function of many variables, for example: the spatial scale of the observations; timing of the observations; the adopted nomenclature for classification; the complexity of the landscape in terms of composition, spatial structure and the physical environment; the habitat and land cover types under consideration. 4. The type of the EO data available varies (function of e.g. budget, size and location of region, cloudiness, national and/or international investment in airborne campaigns or space technology) which determines its capability to deliver the required output. EO and in-situ could be combined in different ways, depending on the type of integration we wanted to achieve and the targeted improvement. We aimed for an improvement in accuracy (i.e. the reduction in error of our indicator estimate calculated for an environmental zone). Furthermore, EO would also provide the spatial patterns for correlated in-situ data. EBONE in its initial development, focused on three main indicators covering: (i) the extent and change of habitats of European interest in the context of a general habitat assessment; (ii) abundance and distribution of selected species (birds, butterflies and plants); and (iii) fragmentation of natural and semi-natural areas. For habitat extent, we decided that it did not matter how in-situ was integrated with EO as long as we could demonstrate that acceptable accuracies could be achieved and the precision could consistently be improved. The nomenclature used to map habitats in-situ was the General Habitat Classification. We considered the following options where the EO and in-situ play different roles: using in-situ samples to re-calibrate a habitat map independently derived from EO; improving the accuracy of in-situ sampled habitat statistics, by post-stratification with correlated EO data; and using in-situ samples to train the classification of EO data into habitat types where the EO data delivers full coverage or a larger number of samples. For some of the above cases we also considered the impact that the sampling strategy employed to deliver the samples would have on the accuracy and precision achieved. Restricted access to European wide species data prevented work on the indicator ‘abundance and distribution of species’. With respect to the indicator ‘fragmentation’, we investigated ways of delivering EO derived measures of habitat patterns that are meaningful to sampled in-situ observations

A method for continuous239Pu determinations in Arctic and Antarctic ice cores

Atmospheric nuclear weapons testing (NWT) resulted in the injection of plutonium (Pu) into the atmosphere and subsequent global deposition. We present a new method for continuous semi-quantitative measurement of 239Pu in ice cores, which was used to develop annual records of fallout from NWT in ten ice cores from Greenland and Antarctica. The 239Pu was measured directly using an Inductively Coupled Plasma – Sector Field Mass Spectrometer, thereby reducing analysis time and increasing depth-resolution with respect to previous methods. To validate this method, we compared our one year averaged results to published 239Pu records and other records of NWT. The 239Pu profiles from four Arctic ice cores reflected global trends in NWT and were in agreement with discrete Pu profiles from lower latitude ice cores. The 239Pu measurements in the Antarctic ice cores tracked low latitude NWT, consistent with previously published discrete records from Antarctica. Advantages of the continuous 239Pu measurement method are (1) reduced sample preparation and analysis time; (2) no requirement for additional ice samples for NWT fallout determinations; (3) measurements are exactly co-registered with all other chemical, elemental, isotopic, and gas measurements from the continuous analytical system; and (4) the long half-life means the 239Pu record is stable through time

Molecular genetic analysis of Giardia intestinalis isolates at the glutamate dehydrogenase locus

Samples of DNA from a panel of Giardia isolated from humans and animals in Europe and shown previously to consist of 2 major genotypes–‘Polish’ and ‘Belgian’–have been compared with human-derived Australian isolates chosen to represent distinct genotypes (genetic groups I–IV) defined previously by allozymic analysis. Homologous 0·52 kilobase (kb) segments of 2 trophozoite surface protein genes (tsa417 and tsp11, both present in isolates belonging to genetic groups I and II) and a 1·2 kb segment of the glutamate dehydrogenase (gdh) gene were amplified by the polymerase chain reaction (PCR) and examined for restriction fragment length polymorphisms (RFLPs). Of 21 ‘Polish’ isolates that were tested, all yielded tsa417-like and tsp11-like PCR products that are characteristic of genetic groups I or II (15 and 6 isolates respectively) in a distinct assemblage of G. intestinalis from Australia (Assemblage A). Conversely, most of the 19 ‘Belgian’ isolates resembled a second assemblage of genotypes defined in Australia (Assemblage B) which contains genetic groups III and IV. RFLP analysis of gdh amplification products showed also that ‘Polish’ isolates-were equivalent to Australian Assemblage A isolates (this analysis does not distinguish between genetic groups I and II) and that ‘Belgian’ isolates were equivalent to Australian Assemblage B isolates. Comparison of nucleotide sequences determined for a 690 base-pair portion of the gdh PCR products revealed ≥ 99·0% identity between group I and group II (Assemblage A/‘Polish’) genotypes, 88·3–89·7% identity between Assemblage A and Assemblage B genotypes, and ≥ 98·4% identity between various Assemblage B/‘Belgian’ genotypes. The results confirm that the G. duodenalis isolates examined in this study (inclusive of G. intestinalis from humans) can be divided into 2 major genetic clusters: Assemblage A (= ‘Polish’ genotype) containing allozymically defined groups I and II, and Assemblage B (= ‘Belgian’ genotype) containing allozymically defined groups III and IV and other related genotypes