33 research outputs found

    Experimental Studies of Flow Patterns of Different Fluids in a Partially Filled Rotating Cylinder

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    An attempt has been made to investigate the various parameters affecting the fluid behaviour, partially filled in a rotating cylinder. When the cylinder is rotating at ‘high’ speed, a liquid forms a hollow cylinder. Different patterns are observed in the fluids for the rotatioal speeds below a critical speed. This study should give us some insight into molten metal behaviour during centrifugal casting. An extensive experimental investigation is required to obtain an appropriate functional relationship by knowing and understanding some dimensionless parameters. Here the effect of dimensionless parameters ε (which is 2 g/ω2d, where g, ω and d denotes gravitational acceleration, container rotation rate and inner diameter of liquid cylinder) and G (number of times the gravity) was studied as variation of rotation speed, viscosity and aspect ratio of the mould

    UniHI 7: an enhanced database for retrieval and interactive analysis of human molecular interaction networks.

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    Unified Human Interactome (UniHI) (http://www.unihi.org) is a database for retrieval, analysis and visualization of human molecular interaction networks. Its primary aim is to provide a comprehensive and easy-to-use platform for network-based investigations to a wide community of researchers in biology and medicine. Here, we describe a major update (version 7) of the database previously featured in NAR Database Issue. UniHI 7 currently includes almost 350,000 molecular interactions between genes, proteins and drugs, as well as numerous other types of data such as gene expression and functional annotation. Multiple options for interactive filtering and highlighting of proteins can be employed to obtain more reliable and specific network structures. Expression and other genomic data can be uploaded by the user to examine local network structures. Additional built-in tools enable ready identification of known drug targets, as well as of biological processes, phenotypes and pathways enriched with network proteins. A distinctive feature of UniHI 7 is its user-friendly interface designed to be utilized in an intuitive manner, enabling researchers less acquainted with network analysis to perform state-of-the-art network-based investigations

    RANTES/CCL5 and risk for coronary events: Results from the MONICA/KORA Augsburg case-cohort, Athero-express and CARDIoGRAM studies

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    Background: The chemokine RANTES (regulated on activation, normal T-cell expressed and secreted)/CCL5 is involved in the pathogenesis of cardiovascular disease in mice, whereas less is known in humans. We hypothesised that its relevance for atherosclerosis should be reflected by associations between CCL5 gene variants, RANTES serum concentrations and protein levels in atherosclerotic plaques and risk for coronary events. Methods and Findings: We conducted a case-cohort study within the population-based MONICA/KORA Augsburg studies. Baseline RANTES serum levels were measured in 363 individuals with incident coronary events and 1,908 non-cases (mean follow-up: 10.2±

    Large expert-curated database for benchmarking document similarity detection in biomedical literature search

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    Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

    The Cholecystectomy As A Day Case (CAAD) Score: A Validated Score of Preoperative Predictors of Successful Day-Case Cholecystectomy Using the CholeS Data Set

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    Background Day-case surgery is associated with significant patient and cost benefits. However, only 43% of cholecystectomy patients are discharged home the same day. One hypothesis is day-case cholecystectomy rates, defined as patients discharged the same day as their operation, may be improved by better assessment of patients using standard preoperative variables. Methods Data were extracted from a prospectively collected data set of cholecystectomy patients from 166 UK and Irish hospitals (CholeS). Cholecystectomies performed as elective procedures were divided into main (75%) and validation (25%) data sets. Preoperative predictors were identified, and a risk score of failed day case was devised using multivariate logistic regression. Receiver operating curve analysis was used to validate the score in the validation data set. Results Of the 7426 elective cholecystectomies performed, 49% of these were discharged home the same day. Same-day discharge following cholecystectomy was less likely with older patients (OR 0.18, 95% CI 0.15–0.23), higher ASA scores (OR 0.19, 95% CI 0.15–0.23), complicated cholelithiasis (OR 0.38, 95% CI 0.31 to 0.48), male gender (OR 0.66, 95% CI 0.58–0.74), previous acute gallstone-related admissions (OR 0.54, 95% CI 0.48–0.60) and preoperative endoscopic intervention (OR 0.40, 95% CI 0.34–0.47). The CAAD score was developed using these variables. When applied to the validation subgroup, a CAAD score of ≤5 was associated with 80.8% successful day-case cholecystectomy compared with 19.2% associated with a CAAD score >5 (p < 0.001). Conclusions The CAAD score which utilises data readily available from clinic letters and electronic sources can predict same-day discharges following cholecystectomy

    Experimental evidence on the prolonged stability of CO2 hydrates in the self-preservation region

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    Most chemical engineering firms value carbon dioxide as a valuable commodity and the main greenhouse gas that is alarming climate change. The importance of limiting CO2 emissions while also providing sectors with beneficial CO2 is paramount. The current work defines the viability of CO2 capture via gas hydrates, followed by storage and transportation. 0.5 wt% of l-methionine amino acid powder is used as an additive. The experiments were performed in non-stir conditions, and the CO2 hydrate nucleation was observed at 268.3 ± 2.2 K and 2370.7 ± 56.2 kPa. l-methionine accelerated the gas uptake kinetics, and 90% of the hydrate conversion was within 28.7 ± 4.6 minutes, which is 6.25 times faster than the bulk system (without additive). It acted as a catalyst and did not alter the hydrate's structural characteristics. The stochastic nature of hydrate nucleation is abated, and water reuse yielded a similar conversion. The maximum achieved CO2 hydrate yield is 100.3 ± 1.5 v/v, accounting for ∼67% of the maximum feasible value (149.3 v/v). For viable transportation of the captured CO2 in hydrate form, the self-preservation phenomenon is experimentally evaluated at ∼268 K. The study established the prolonged stability of CO2 hydrates in the self-preservation zone for 50 hours. The hydrate preservation is interrelated to the ice capping theory, which describes how a thin layer of liquid water forms on the surface of the hydrate and eventually freezes to form the ice cap. The boil-off observed due to the hydrate melting, and self-annealing was 25% of the total gas. Regasification is easy and accomplished by raising the temperature over the ice melting point. The findings highlight the significance of more extended hydrate stability in the self-preservation window, which could be a valuable tool for CO2 storage and transportation under milder pressure-temperature conditions

    A Comparative Study of DG Impacts on Power System Stability under Equal and Unequal Load Growth Scenarios

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    The distributed generation (DG) technology is developed to meet the increasing load demand at a load centre by exploring locally available energy sources, including renewables. Although DG technology offers many technical and economic benefits, certain issues need further research. The impact of DG penetration on the system’s stability is one such issue that requires significant attention in power system research. This study investigates the impact of DG penetration on the system’s small-signal and transient stability under equal and unequal load growth scenarios. The unequal load growth condition is simulated by employing an orthogonal array (OA), and the impact of DG penetration on small-signal stability is analyzed through critical eigenvalues while time-domain indicators were employed to analyze transient stability. The importance of unequal load growth conditions while evaluating the impact of DG penetration on stability is demonstrated on a 3 generators, 9 bus WSCC power system

    Experimental investigations on tetrahydrofuran – methane – water system: Rapid methane gas storage in hydrates

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    This study reports methane (CH4) gas storage capacity along with TetraHydroFuran (THF) as guest molecules in mixed hydrates. This process has been studied in two reactors of 100 and 400 mL capacity, having 4.5 and 7.5 cm internal diameter respectively, in non-stirred configuration. Experiments were conducted in each reactor at constant initial gas pressure (7.5 MPa) and by increasing the height of the solution from 1 to 8 cm, resulting in volume scale-up factor of 5. The total CH4 gas uptake (moles) passes through a maximum at around 50% volume of the reactor indicating a transition from gas-rich to solution rich conditions. Observed variations in gas uptake are within ±20% of the maximum, upon different solution volume from 35% to 70% of reactor’s volume. Another set of experiments were conducted keeping the amount of the solution constant and increasing gas pressure in the range of 0.5–11.0 MPa. The gas uptake increased upon an increase in the gas pressure, but this is at least 40% less compared to the theoretical estimate. The stirring of solution or addition of promoter (Sodium Dodecyl Sulfate, SDS) is also not effective in increasing the gas consumption. Kinetics of gas uptake, in both stirred and non-stirred conditions, are quicker and 90% of gas consumption occurs in an hour after the hydrate nucleation event
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