An experimental and computational strategy for an increased understanding of two-phase flow of natural gas

Paper presented at the 5th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 1-4 July, 2007.This paper presents a research strategy aimed towards understanding transient two-phase flow in compact low temperature equipment, with emphasis on heat exchangers. The strategy is based on the hypothesis that to meet the many two-phase challenges occurring in compact process equipment, detailed knowledge about basic flow phenomena is needed. To provide this knowledge, a relevant computer simulation model and experimental setups are under development. The computer model is based on the level-set method, which is suitable for detailed two-phase flow calculations, and which has been shown to be able to reproduce flow phenomena observed in small channels. Two experimental setups are presented, one for measuring details regarding flow topology, such as film behaviour, droplet tear-off, droplet-droplet and droplet-film interaction, and a second for measuring integral quantities like pressure drop and heat transfer during condensation of natural gas mixtures in microtubes. The tubes range from 0.25–1 mm in diameter and the experiments will be performed at low temperatures. This setup will provide data to design compact heat exchangers

Epidemiology and outcomes of Clostridium difficile infection in allogeneic hematopoietic cell and lung transplant recipients

BackgroundClostridium difficile infection (CDI) is a common complication of lung and allogeneic hematopoietic cell (HCT) transplant, but the epidemiology and outcomes of CDI after transplant are poorly described.MethodsWe performed a prospective, multicenter study of CDI within 365 days post‐allogeneic HCT or lung transplantation. Data were collected via patient interviews and medical chart review. Participants were followed weekly in the 12 weeks post‐transplant and while hospitalized and contacted monthly up to 18 months post‐transplantation.ResultsSix sites participated in the study with 614 total participants; 4 enrolled allogeneic HCT (385 participants) and 5 enrolled lung transplant recipients (229 participants). One hundred and fifty CDI cases occurred within 1 year of transplantation; the incidence among lung transplant recipients was 13.1% and among allogeneic HCTs was 31.2%. Median time to CDI was significantly shorter among allogeneic HCT than lung transplant recipients (27 days vs 90 days; P = .037). CDI was associated with significantly higher mortality from 31 to 180 days post‐index date among the allogeneic HCT recipients (Hazard ratio [HR] = 1.80; P = .007). There was a trend towards increased mortality among lung transplant recipients from 120 to 180 days post‐index date (HR = 4.7, P = .09).ConclusionsThe epidemiology and outcomes of CDI vary by transplant population; surveillance for CDI should continue beyond the immediate post‐transplant period.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/143790/1/tid12855_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/143790/2/tid12855.pd

First-principles extrapolation method for accurate CO adsorption energies on metal surfaces

We show that a simple first-principles correction based on the difference between the singlet-triplet CO excitation energy values obtained by DFT and high-level quantum chemistry methods yields accurate CO adsorption properties on a variety of metal surfaces. We demonstrate a linear relationship between the CO adsorption energy and the CO singlet-triplet splitting, similar to the linear dependence of CO adsorption energy on the energy of the CO 2$\pi$* orbital found recently {[Kresse {\em et al.}, Physical Review B {\bf 68}, 073401 (2003)]}. Converged DFT calculations underestimate the CO singlet-triplet excitation energy $\Delta E_{\rm S-T}$, whereas coupled-cluster and CI calculations reproduce the experimental $\Delta E_{\rm S-T}$. The dependence of $E_{\rm chem}$ on $\Delta E_{\rm S-T}$ is used to extrapolate $E_{\rm chem}$ for the top, bridge and hollow sites for the (100) and (111) surfaces of Pt, Rh, Pd and Cu to the values that correspond to the coupled-cluster and CI $\Delta E_{\rm S-T}$ value. The correction reproduces experimental adsorption site preference for all cases and obtains $E_{\rm chem}$ in excellent agreement with experimental results.Comment: Table sent as table1.eps. 3 figure

Supporting users tasks with personal information management and web forms augmentation

Currently, many tasks performed on the Web prompt users to provide personal information through forms. Despite the fact that most users are familiarized with this kind of interaction technique, the use of Web forms is not always straightforward. Indeed, some users might need assistance to understand labels and complex data format required to fill in form fields that, quite often, vary from a Web site to another even when requesting similar data. Filling in forms can be tedious and repetitive as many Web sites request similar information. In this work we analyze user's interactions with Web forms and propose an approach for enhancing Web forms using client-side adaptation techniques in order to assist users to fill in Web forms. As the use of Web forms is closely related to the management of personal information our approach includes the support for data exchange between user's personal information management systems (PIMs) and third-party Web forms. The approach is illustrated by a set of client-side adaptation tools and a pervasive Personal Information Management Systems called PIMI.Publicado en Lecture Notes in Computer Science book series (vol. 7387).Laboratorio de Investigación y Formación en Informática Avanzad

Very Strong Binding for a Neutral Calix[4]pyrrole Receptor Displaying Positive Allosteric Binding

The dual-analyte responsive behavior of tetraTTF-calix[4]pyrrole receptor 1 has been shown to complex electron-deficient planar guests in a 2:1 fashion by adopting a so-called 1,3-alternate conformation. However, stronger 1:1 complexes have been demonstrated with tetraalkylammonium halide salts that defer receptor 1 to its cone conformation. Herein, we report the complexation of an electron-deficient planar guest, 1,4,5,8-naphthalenetetracarboxylic dianhydride (NTCDA, 2) that champions the complexation with 1, resulting in a high association constant Ka = 3 × 1010 M–2. The tetrathiafulvalene (TTF) subunits in the tetraTTF-calix[4]pyrrole receptor 1 present a near perfect shape and electronic complementarity to the NTCDA guest, which was confirmed by X-ray crystal structure analysis, DFT calculations, and electron density surface mapping. Moreover, the complexation of these species results in the formation of a charge transfer complex (22⊂1) as visualized by a readily apparent color change from yellow to brown

Exploring Large Digital Library Collections Using a Map-Based Visualisation

In this paper we describe a novel approach for exploring large document collections using a map-based visualisation. We use hierarchically structured semantic concepts that are attached to the documents to create a visualisation of the semantic space that resembles a Google Map. The approach is novel in that we exploit the hierarchical structure to enable the approach to scale to large document collections and to create a map where the higher levels of spatial abstraction have semantic meaning. An informal evaluation is carried out to gather subjective feedback from users. Overall results are positive with users finding the visualisation enticing and easy to use

Study protocol: Our Cultures Count, the Mayi Kuwayu Study, a national longitudinal study of Aboriginal and Torres Strait Islander wellbeing

IntroductionAboriginal and Torres Strait Islander peoples are Australia's first peoples and have been connected to the land for ≥65 000 years. Their enduring cultures and values are considered critical to health and wellbeing, alongside physical, psychological and social factors. We currently lack large-scale data that adequately represent the experiences of Aboriginal and Torres Strait Islander people; the absence of evidence on cultural practice and expression is particularly striking, given its foundational importance to wellbeing.Method and analysisMayi Kuwayu: The National Study of Aboriginal and Torres Strait Islander Wellbeing (Mayi Kuwayu Study) will be a large-scale, national longitudinal study of Aboriginal and Torres Strait Islander adults, with linkage to health-related administrative records. The baseline survey was developed through extensive community consultation, and includes items on: cultural practice and expression, sociodemographic factors, health and wellbeing, health behaviours, experiences and environments, and family support and connection. The baseline survey will be mailed to 200 000 Aboriginal and Torres Strait Islander adults (≥16 years), yielding an estimated 16 000-40 000 participants, supplemented through face-to-face recruitment. Follow-up surveys will be conducted every 3-5 years, or as funding allows. The Mayi Kuwayu Study will contribute to filling key evidence gaps, including quantifying the contribution of cultural factors to wellbeing, alongside standard elements of health and risk.Ethics and disseminationThis study has received approval from national Human Research Ethics Committees, and from State and Territory committees, including relevant Aboriginal and Torres Strait Islander organisations. The study was developed and is conducted in partnership with Aboriginal and Torres Strait Islander organisations across states and territories. It will provide an enduring and shared infrastructure to underpin programme and policy development, based on measures and values important to Aboriginal and Torres Strait Islander peoples. Approved researchers can access confidentialised data and disseminate findings according to study data access and governance protocols.Roxanne Jones, Katherine A Thurber, Jan Chapman, Catherine D, Este, Terry Dunbar, Mark Wenitong, Sandra J Eades, Lisa Strelein, Maureen Davey, Wei Du, Anna Olsen, Janet K Smylie, Emily Banks, Raymond Lovett, on behalf of the Mayi Kuwayu Study Tea

Search for a W' boson decaying to a bottom quark and a top quark in pp collisions at sqrt(s) = 7 TeV

Results are presented from a search for a W' boson using a dataset corresponding to 5.0 inverse femtobarns of integrated luminosity collected during 2011 by the CMS experiment at the LHC in pp collisions at sqrt(s)=7 TeV. The W' boson is modeled as a heavy W boson, but different scenarios for the couplings to fermions are considered, involving both left-handed and right-handed chiral projections of the fermions, as well as an arbitrary mixture of the two. The search is performed in the decay channel W' to t b, leading to a final state signature with a single lepton (e, mu), missing transverse energy, and jets, at least one of which is tagged as a b-jet. A W' boson that couples to fermions with the same coupling constant as the W, but to the right-handed rather than left-handed chiral projections, is excluded for masses below 1.85 TeV at the 95% confidence level. For the first time using LHC data, constraints on the W' gauge coupling for a set of left- and right-handed coupling combinations have been placed. These results represent a significant improvement over previously published limits.Comment: Submitted to Physics Letters B. Replaced with version publishe